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2378 lines
60 KiB
2378 lines
60 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/anon_inodes.h> |
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#include <linux/atomic.h> |
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#include <linux/bitmap.h> |
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#include <linux/build_bug.h> |
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#include <linux/cdev.h> |
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#include <linux/compat.h> |
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#include <linux/compiler.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/file.h> |
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#include <linux/gpio.h> |
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#include <linux/gpio/driver.h> |
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#include <linux/interrupt.h> |
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#include <linux/irqreturn.h> |
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#include <linux/kernel.h> |
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#include <linux/kfifo.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/pinctrl/consumer.h> |
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#include <linux/poll.h> |
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#include <linux/spinlock.h> |
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#include <linux/timekeeping.h> |
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#include <linux/uaccess.h> |
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#include <linux/workqueue.h> |
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#include <uapi/linux/gpio.h> |
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#include "gpiolib.h" |
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#include "gpiolib-cdev.h" |
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/* |
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* Array sizes must ensure 64-bit alignment and not create holes in the |
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* struct packing. |
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*/ |
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static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); |
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static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); |
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|
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/* |
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* Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility |
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*/ |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); |
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static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); |
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|
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/* Character device interface to GPIO. |
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* |
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* The GPIO character device, /dev/gpiochipN, provides userspace an |
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* interface to gpiolib GPIOs via ioctl()s. |
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*/ |
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|
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/* |
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* GPIO line handle management |
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*/ |
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#ifdef CONFIG_GPIO_CDEV_V1 |
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/** |
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* struct linehandle_state - contains the state of a userspace handle |
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* @gdev: the GPIO device the handle pertains to |
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* @label: consumer label used to tag descriptors |
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* @descs: the GPIO descriptors held by this handle |
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* @num_descs: the number of descriptors held in the descs array |
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*/ |
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struct linehandle_state { |
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struct gpio_device *gdev; |
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const char *label; |
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struct gpio_desc *descs[GPIOHANDLES_MAX]; |
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u32 num_descs; |
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}; |
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#define GPIOHANDLE_REQUEST_VALID_FLAGS \ |
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(GPIOHANDLE_REQUEST_INPUT | \ |
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GPIOHANDLE_REQUEST_OUTPUT | \ |
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GPIOHANDLE_REQUEST_ACTIVE_LOW | \ |
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GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ |
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GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ |
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GPIOHANDLE_REQUEST_BIAS_DISABLE | \ |
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GPIOHANDLE_REQUEST_OPEN_DRAIN | \ |
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GPIOHANDLE_REQUEST_OPEN_SOURCE) |
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|
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static int linehandle_validate_flags(u32 flags) |
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{ |
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/* Return an error if an unknown flag is set */ |
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if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) |
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return -EINVAL; |
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/* |
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* Do not allow both INPUT & OUTPUT flags to be set as they are |
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* contradictory. |
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*/ |
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if ((flags & GPIOHANDLE_REQUEST_INPUT) && |
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(flags & GPIOHANDLE_REQUEST_OUTPUT)) |
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return -EINVAL; |
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|
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/* |
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* Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If |
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* the hardware actually supports enabling both at the same time the |
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* electrical result would be disastrous. |
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*/ |
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if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && |
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(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) |
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return -EINVAL; |
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|
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/* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ |
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if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && |
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((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || |
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(flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) |
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return -EINVAL; |
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|
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/* Bias flags only allowed for input or output mode. */ |
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if (!((flags & GPIOHANDLE_REQUEST_INPUT) || |
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(flags & GPIOHANDLE_REQUEST_OUTPUT)) && |
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((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || |
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || |
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) |
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return -EINVAL; |
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|
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/* Only one bias flag can be set. */ |
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if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && |
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(flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | |
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GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || |
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((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && |
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(flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) |
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return -EINVAL; |
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|
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return 0; |
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} |
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static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp) |
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{ |
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assign_bit(FLAG_ACTIVE_LOW, flagsp, |
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lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); |
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assign_bit(FLAG_OPEN_DRAIN, flagsp, |
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lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); |
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assign_bit(FLAG_OPEN_SOURCE, flagsp, |
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lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); |
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assign_bit(FLAG_PULL_UP, flagsp, |
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lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); |
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assign_bit(FLAG_PULL_DOWN, flagsp, |
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lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); |
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assign_bit(FLAG_BIAS_DISABLE, flagsp, |
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lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); |
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} |
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static long linehandle_set_config(struct linehandle_state *lh, |
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void __user *ip) |
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{ |
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struct gpiohandle_config gcnf; |
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struct gpio_desc *desc; |
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int i, ret; |
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u32 lflags; |
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|
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if (copy_from_user(&gcnf, ip, sizeof(gcnf))) |
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return -EFAULT; |
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lflags = gcnf.flags; |
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ret = linehandle_validate_flags(lflags); |
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if (ret) |
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return ret; |
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for (i = 0; i < lh->num_descs; i++) { |
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desc = lh->descs[i]; |
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linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags); |
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/* |
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* Lines have to be requested explicitly for input |
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* or output, else the line will be treated "as is". |
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*/ |
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if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { |
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int val = !!gcnf.default_values[i]; |
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ret = gpiod_direction_output(desc, val); |
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if (ret) |
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return ret; |
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} else if (lflags & GPIOHANDLE_REQUEST_INPUT) { |
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ret = gpiod_direction_input(desc); |
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if (ret) |
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return ret; |
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} |
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blocking_notifier_call_chain(&desc->gdev->notifier, |
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GPIO_V2_LINE_CHANGED_CONFIG, |
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desc); |
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} |
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return 0; |
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} |
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static long linehandle_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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struct linehandle_state *lh = file->private_data; |
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void __user *ip = (void __user *)arg; |
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struct gpiohandle_data ghd; |
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DECLARE_BITMAP(vals, GPIOHANDLES_MAX); |
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int i; |
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|
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if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { |
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/* NOTE: It's ok to read values of output lines. */ |
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int ret = gpiod_get_array_value_complex(false, |
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true, |
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lh->num_descs, |
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lh->descs, |
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NULL, |
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vals); |
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if (ret) |
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return ret; |
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memset(&ghd, 0, sizeof(ghd)); |
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for (i = 0; i < lh->num_descs; i++) |
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ghd.values[i] = test_bit(i, vals); |
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if (copy_to_user(ip, &ghd, sizeof(ghd))) |
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return -EFAULT; |
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|
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return 0; |
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} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) { |
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/* |
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* All line descriptors were created at once with the same |
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* flags so just check if the first one is really output. |
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*/ |
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if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) |
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return -EPERM; |
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if (copy_from_user(&ghd, ip, sizeof(ghd))) |
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return -EFAULT; |
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|
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/* Clamp all values to [0,1] */ |
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for (i = 0; i < lh->num_descs; i++) |
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__assign_bit(i, vals, ghd.values[i]); |
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|
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/* Reuse the array setting function */ |
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return gpiod_set_array_value_complex(false, |
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true, |
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lh->num_descs, |
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lh->descs, |
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NULL, |
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vals); |
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} else if (cmd == GPIOHANDLE_SET_CONFIG_IOCTL) { |
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return linehandle_set_config(lh, ip); |
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} |
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return -EINVAL; |
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} |
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#ifdef CONFIG_COMPAT |
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static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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return linehandle_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
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} |
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#endif |
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static void linehandle_free(struct linehandle_state *lh) |
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{ |
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int i; |
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for (i = 0; i < lh->num_descs; i++) |
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if (lh->descs[i]) |
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gpiod_free(lh->descs[i]); |
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kfree(lh->label); |
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put_device(&lh->gdev->dev); |
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kfree(lh); |
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} |
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static int linehandle_release(struct inode *inode, struct file *file) |
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{ |
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linehandle_free(file->private_data); |
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return 0; |
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} |
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|
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static const struct file_operations linehandle_fileops = { |
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.release = linehandle_release, |
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.owner = THIS_MODULE, |
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.llseek = noop_llseek, |
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.unlocked_ioctl = linehandle_ioctl, |
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#ifdef CONFIG_COMPAT |
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.compat_ioctl = linehandle_ioctl_compat, |
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#endif |
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}; |
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static int linehandle_create(struct gpio_device *gdev, void __user *ip) |
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{ |
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struct gpiohandle_request handlereq; |
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struct linehandle_state *lh; |
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struct file *file; |
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int fd, i, ret; |
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u32 lflags; |
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if (copy_from_user(&handlereq, ip, sizeof(handlereq))) |
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return -EFAULT; |
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if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) |
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return -EINVAL; |
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lflags = handlereq.flags; |
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ret = linehandle_validate_flags(lflags); |
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if (ret) |
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return ret; |
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lh = kzalloc(sizeof(*lh), GFP_KERNEL); |
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if (!lh) |
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return -ENOMEM; |
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lh->gdev = gdev; |
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get_device(&gdev->dev); |
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if (handlereq.consumer_label[0] != '\0') { |
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/* label is only initialized if consumer_label is set */ |
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lh->label = kstrndup(handlereq.consumer_label, |
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sizeof(handlereq.consumer_label) - 1, |
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GFP_KERNEL); |
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if (!lh->label) { |
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ret = -ENOMEM; |
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goto out_free_lh; |
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} |
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} |
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lh->num_descs = handlereq.lines; |
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/* Request each GPIO */ |
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for (i = 0; i < handlereq.lines; i++) { |
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u32 offset = handlereq.lineoffsets[i]; |
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struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); |
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if (IS_ERR(desc)) { |
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ret = PTR_ERR(desc); |
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goto out_free_lh; |
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} |
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ret = gpiod_request(desc, lh->label); |
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if (ret) |
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goto out_free_lh; |
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lh->descs[i] = desc; |
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linehandle_flags_to_desc_flags(handlereq.flags, &desc->flags); |
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|
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ret = gpiod_set_transitory(desc, false); |
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if (ret < 0) |
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goto out_free_lh; |
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/* |
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* Lines have to be requested explicitly for input |
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* or output, else the line will be treated "as is". |
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*/ |
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if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { |
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int val = !!handlereq.default_values[i]; |
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ret = gpiod_direction_output(desc, val); |
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if (ret) |
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goto out_free_lh; |
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} else if (lflags & GPIOHANDLE_REQUEST_INPUT) { |
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ret = gpiod_direction_input(desc); |
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if (ret) |
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goto out_free_lh; |
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} |
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blocking_notifier_call_chain(&desc->gdev->notifier, |
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GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
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|
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dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
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offset); |
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} |
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|
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fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
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if (fd < 0) { |
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ret = fd; |
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goto out_free_lh; |
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} |
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file = anon_inode_getfile("gpio-linehandle", |
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&linehandle_fileops, |
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lh, |
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O_RDONLY | O_CLOEXEC); |
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if (IS_ERR(file)) { |
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ret = PTR_ERR(file); |
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goto out_put_unused_fd; |
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} |
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handlereq.fd = fd; |
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if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { |
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/* |
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* fput() will trigger the release() callback, so do not go onto |
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* the regular error cleanup path here. |
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*/ |
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fput(file); |
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put_unused_fd(fd); |
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return -EFAULT; |
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} |
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fd_install(fd, file); |
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dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", |
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lh->num_descs); |
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return 0; |
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out_put_unused_fd: |
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put_unused_fd(fd); |
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out_free_lh: |
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linehandle_free(lh); |
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return ret; |
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} |
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#endif /* CONFIG_GPIO_CDEV_V1 */ |
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|
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/** |
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* struct line - contains the state of a requested line |
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* @desc: the GPIO descriptor for this line. |
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* @req: the corresponding line request |
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* @irq: the interrupt triggered in response to events on this GPIO |
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* @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or |
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* GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied |
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* @timestamp_ns: cache for the timestamp storing it between hardirq and |
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* IRQ thread, used to bring the timestamp close to the actual event |
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* @req_seqno: the seqno for the current edge event in the sequence of |
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* events for the corresponding line request. This is drawn from the @req. |
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* @line_seqno: the seqno for the current edge event in the sequence of |
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* events for this line. |
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* @work: the worker that implements software debouncing |
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* @sw_debounced: flag indicating if the software debouncer is active |
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* @level: the current debounced physical level of the line |
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*/ |
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struct line { |
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struct gpio_desc *desc; |
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/* |
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* -- edge detector specific fields -- |
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*/ |
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struct linereq *req; |
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unsigned int irq; |
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/* |
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* eflags is set by edge_detector_setup(), edge_detector_stop() and |
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* edge_detector_update(), which are themselves mutually exclusive, |
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* and is accessed by edge_irq_thread() and debounce_work_func(), |
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* which can both live with a slightly stale value. |
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*/ |
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u64 eflags; |
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/* |
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* timestamp_ns and req_seqno are accessed only by |
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* edge_irq_handler() and edge_irq_thread(), which are themselves |
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* mutually exclusive, so no additional protection is necessary. |
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*/ |
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u64 timestamp_ns; |
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u32 req_seqno; |
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/* |
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* line_seqno is accessed by either edge_irq_thread() or |
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* debounce_work_func(), which are themselves mutually exclusive, |
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* so no additional protection is necessary. |
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*/ |
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u32 line_seqno; |
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/* |
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* -- debouncer specific fields -- |
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*/ |
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struct delayed_work work; |
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/* |
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* sw_debounce is accessed by linereq_set_config(), which is the |
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* only setter, and linereq_get_values(), which can live with a |
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* slightly stale value. |
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*/ |
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unsigned int sw_debounced; |
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/* |
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* level is accessed by debounce_work_func(), which is the only |
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* setter, and linereq_get_values() which can live with a slightly |
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* stale value. |
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*/ |
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unsigned int level; |
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}; |
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|
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/** |
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* struct linereq - contains the state of a userspace line request |
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* @gdev: the GPIO device the line request pertains to |
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* @label: consumer label used to tag GPIO descriptors |
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* @num_lines: the number of lines in the lines array |
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* @wait: wait queue that handles blocking reads of events |
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* @event_buffer_size: the number of elements allocated in @events |
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* @events: KFIFO for the GPIO events |
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* @seqno: the sequence number for edge events generated on all lines in |
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* this line request. Note that this is not used when @num_lines is 1, as |
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* the line_seqno is then the same and is cheaper to calculate. |
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* @config_mutex: mutex for serializing ioctl() calls to ensure consistency |
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* of configuration, particularly multi-step accesses to desc flags. |
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* @lines: the lines held by this line request, with @num_lines elements. |
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*/ |
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struct linereq { |
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struct gpio_device *gdev; |
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const char *label; |
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u32 num_lines; |
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wait_queue_head_t wait; |
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u32 event_buffer_size; |
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DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); |
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atomic_t seqno; |
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struct mutex config_mutex; |
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struct line lines[]; |
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}; |
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|
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#define GPIO_V2_LINE_BIAS_FLAGS \ |
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(GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ |
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GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ |
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GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
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|
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#define GPIO_V2_LINE_DIRECTION_FLAGS \ |
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(GPIO_V2_LINE_FLAG_INPUT | \ |
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GPIO_V2_LINE_FLAG_OUTPUT) |
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|
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#define GPIO_V2_LINE_DRIVE_FLAGS \ |
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(GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ |
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GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
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|
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#define GPIO_V2_LINE_EDGE_FLAGS \ |
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(GPIO_V2_LINE_FLAG_EDGE_RISING | \ |
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GPIO_V2_LINE_FLAG_EDGE_FALLING) |
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|
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#define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS |
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|
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#define GPIO_V2_LINE_VALID_FLAGS \ |
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(GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ |
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GPIO_V2_LINE_DIRECTION_FLAGS | \ |
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GPIO_V2_LINE_DRIVE_FLAGS | \ |
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GPIO_V2_LINE_EDGE_FLAGS | \ |
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GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ |
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GPIO_V2_LINE_BIAS_FLAGS) |
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|
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static void linereq_put_event(struct linereq *lr, |
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struct gpio_v2_line_event *le) |
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{ |
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bool overflow = false; |
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|
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spin_lock(&lr->wait.lock); |
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if (kfifo_is_full(&lr->events)) { |
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overflow = true; |
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kfifo_skip(&lr->events); |
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} |
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kfifo_in(&lr->events, le, 1); |
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spin_unlock(&lr->wait.lock); |
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if (!overflow) |
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wake_up_poll(&lr->wait, EPOLLIN); |
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else |
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pr_debug_ratelimited("event FIFO is full - event dropped\n"); |
|
} |
|
|
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static u64 line_event_timestamp(struct line *line) |
|
{ |
|
if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) |
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return ktime_get_real_ns(); |
|
|
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return ktime_get_ns(); |
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} |
|
|
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static irqreturn_t edge_irq_thread(int irq, void *p) |
|
{ |
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struct line *line = p; |
|
struct linereq *lr = line->req; |
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struct gpio_v2_line_event le; |
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u64 eflags; |
|
|
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/* Do not leak kernel stack to userspace */ |
|
memset(&le, 0, sizeof(le)); |
|
|
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if (line->timestamp_ns) { |
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le.timestamp_ns = line->timestamp_ns; |
|
} else { |
|
/* |
|
* We may be running from a nested threaded interrupt in |
|
* which case we didn't get the timestamp from |
|
* edge_irq_handler(). |
|
*/ |
|
le.timestamp_ns = line_event_timestamp(line); |
|
if (lr->num_lines != 1) |
|
line->req_seqno = atomic_inc_return(&lr->seqno); |
|
} |
|
line->timestamp_ns = 0; |
|
|
|
eflags = READ_ONCE(line->eflags); |
|
if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) { |
|
int level = gpiod_get_value_cansleep(line->desc); |
|
|
|
if (level) |
|
/* Emit low-to-high event */ |
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
|
else |
|
/* Emit high-to-low event */ |
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
|
} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) { |
|
/* Emit low-to-high event */ |
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
|
} else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) { |
|
/* Emit high-to-low event */ |
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
|
} else { |
|
return IRQ_NONE; |
|
} |
|
line->line_seqno++; |
|
le.line_seqno = line->line_seqno; |
|
le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; |
|
le.offset = gpio_chip_hwgpio(line->desc); |
|
|
|
linereq_put_event(lr, &le); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static irqreturn_t edge_irq_handler(int irq, void *p) |
|
{ |
|
struct line *line = p; |
|
struct linereq *lr = line->req; |
|
|
|
/* |
|
* Just store the timestamp in hardirq context so we get it as |
|
* close in time as possible to the actual event. |
|
*/ |
|
line->timestamp_ns = line_event_timestamp(line); |
|
|
|
if (lr->num_lines != 1) |
|
line->req_seqno = atomic_inc_return(&lr->seqno); |
|
|
|
return IRQ_WAKE_THREAD; |
|
} |
|
|
|
/* |
|
* returns the current debounced logical value. |
|
*/ |
|
static bool debounced_value(struct line *line) |
|
{ |
|
bool value; |
|
|
|
/* |
|
* minor race - debouncer may be stopped here, so edge_detector_stop() |
|
* must leave the value unchanged so the following will read the level |
|
* from when the debouncer was last running. |
|
*/ |
|
value = READ_ONCE(line->level); |
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
|
value = !value; |
|
|
|
return value; |
|
} |
|
|
|
static irqreturn_t debounce_irq_handler(int irq, void *p) |
|
{ |
|
struct line *line = p; |
|
|
|
mod_delayed_work(system_wq, &line->work, |
|
usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static void debounce_work_func(struct work_struct *work) |
|
{ |
|
struct gpio_v2_line_event le; |
|
struct line *line = container_of(work, struct line, work.work); |
|
struct linereq *lr; |
|
int level; |
|
u64 eflags; |
|
|
|
level = gpiod_get_raw_value_cansleep(line->desc); |
|
if (level < 0) { |
|
pr_debug_ratelimited("debouncer failed to read line value\n"); |
|
return; |
|
} |
|
|
|
if (READ_ONCE(line->level) == level) |
|
return; |
|
|
|
WRITE_ONCE(line->level, level); |
|
|
|
/* -- edge detection -- */ |
|
eflags = READ_ONCE(line->eflags); |
|
if (!eflags) |
|
return; |
|
|
|
/* switch from physical level to logical - if they differ */ |
|
if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) |
|
level = !level; |
|
|
|
/* ignore edges that are not being monitored */ |
|
if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || |
|
((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) |
|
return; |
|
|
|
/* Do not leak kernel stack to userspace */ |
|
memset(&le, 0, sizeof(le)); |
|
|
|
lr = line->req; |
|
le.timestamp_ns = line_event_timestamp(line); |
|
le.offset = gpio_chip_hwgpio(line->desc); |
|
line->line_seqno++; |
|
le.line_seqno = line->line_seqno; |
|
le.seqno = (lr->num_lines == 1) ? |
|
le.line_seqno : atomic_inc_return(&lr->seqno); |
|
|
|
if (level) |
|
/* Emit low-to-high event */ |
|
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; |
|
else |
|
/* Emit high-to-low event */ |
|
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; |
|
|
|
linereq_put_event(lr, &le); |
|
} |
|
|
|
static int debounce_setup(struct line *line, |
|
unsigned int debounce_period_us) |
|
{ |
|
unsigned long irqflags; |
|
int ret, level, irq; |
|
|
|
/* try hardware */ |
|
ret = gpiod_set_debounce(line->desc, debounce_period_us); |
|
if (!ret) { |
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
|
return ret; |
|
} |
|
if (ret != -ENOTSUPP) |
|
return ret; |
|
|
|
if (debounce_period_us) { |
|
/* setup software debounce */ |
|
level = gpiod_get_raw_value_cansleep(line->desc); |
|
if (level < 0) |
|
return level; |
|
|
|
irq = gpiod_to_irq(line->desc); |
|
if (irq < 0) |
|
return -ENXIO; |
|
|
|
WRITE_ONCE(line->level, level); |
|
irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; |
|
ret = request_irq(irq, debounce_irq_handler, irqflags, |
|
line->req->label, line); |
|
if (ret) |
|
return ret; |
|
|
|
WRITE_ONCE(line->sw_debounced, 1); |
|
line->irq = irq; |
|
} |
|
return 0; |
|
} |
|
|
|
static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, |
|
unsigned int line_idx) |
|
{ |
|
unsigned int i; |
|
u64 mask = BIT_ULL(line_idx); |
|
|
|
for (i = 0; i < lc->num_attrs; i++) { |
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
|
(lc->attrs[i].mask & mask)) |
|
return true; |
|
} |
|
return false; |
|
} |
|
|
|
static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, |
|
unsigned int line_idx) |
|
{ |
|
unsigned int i; |
|
u64 mask = BIT_ULL(line_idx); |
|
|
|
for (i = 0; i < lc->num_attrs; i++) { |
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && |
|
(lc->attrs[i].mask & mask)) |
|
return lc->attrs[i].attr.debounce_period_us; |
|
} |
|
return 0; |
|
} |
|
|
|
static void edge_detector_stop(struct line *line) |
|
{ |
|
if (line->irq) { |
|
free_irq(line->irq, line); |
|
line->irq = 0; |
|
} |
|
|
|
cancel_delayed_work_sync(&line->work); |
|
WRITE_ONCE(line->sw_debounced, 0); |
|
WRITE_ONCE(line->eflags, 0); |
|
if (line->desc) |
|
WRITE_ONCE(line->desc->debounce_period_us, 0); |
|
/* do not change line->level - see comment in debounced_value() */ |
|
} |
|
|
|
static int edge_detector_setup(struct line *line, |
|
struct gpio_v2_line_config *lc, |
|
unsigned int line_idx, |
|
u64 eflags) |
|
{ |
|
u32 debounce_period_us; |
|
unsigned long irqflags = 0; |
|
int irq, ret; |
|
|
|
if (eflags && !kfifo_initialized(&line->req->events)) { |
|
ret = kfifo_alloc(&line->req->events, |
|
line->req->event_buffer_size, GFP_KERNEL); |
|
if (ret) |
|
return ret; |
|
} |
|
WRITE_ONCE(line->eflags, eflags); |
|
if (gpio_v2_line_config_debounced(lc, line_idx)) { |
|
debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); |
|
ret = debounce_setup(line, debounce_period_us); |
|
if (ret) |
|
return ret; |
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
|
} |
|
|
|
/* detection disabled or sw debouncer will provide edge detection */ |
|
if (!eflags || READ_ONCE(line->sw_debounced)) |
|
return 0; |
|
|
|
irq = gpiod_to_irq(line->desc); |
|
if (irq < 0) |
|
return -ENXIO; |
|
|
|
if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) |
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; |
|
if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) |
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? |
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; |
|
irqflags |= IRQF_ONESHOT; |
|
|
|
/* Request a thread to read the events */ |
|
ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread, |
|
irqflags, line->req->label, line); |
|
if (ret) |
|
return ret; |
|
|
|
line->irq = irq; |
|
return 0; |
|
} |
|
|
|
static int edge_detector_update(struct line *line, |
|
struct gpio_v2_line_config *lc, |
|
unsigned int line_idx, |
|
u64 eflags, bool polarity_change) |
|
{ |
|
unsigned int debounce_period_us = |
|
gpio_v2_line_config_debounce_period(lc, line_idx); |
|
|
|
if ((READ_ONCE(line->eflags) == eflags) && !polarity_change && |
|
(READ_ONCE(line->desc->debounce_period_us) == debounce_period_us)) |
|
return 0; |
|
|
|
/* sw debounced and still will be...*/ |
|
if (debounce_period_us && READ_ONCE(line->sw_debounced)) { |
|
WRITE_ONCE(line->eflags, eflags); |
|
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); |
|
return 0; |
|
} |
|
|
|
/* reconfiguring edge detection or sw debounce being disabled */ |
|
if ((line->irq && !READ_ONCE(line->sw_debounced)) || |
|
(!debounce_period_us && READ_ONCE(line->sw_debounced))) |
|
edge_detector_stop(line); |
|
|
|
return edge_detector_setup(line, lc, line_idx, eflags); |
|
} |
|
|
|
static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, |
|
unsigned int line_idx) |
|
{ |
|
unsigned int i; |
|
u64 mask = BIT_ULL(line_idx); |
|
|
|
for (i = 0; i < lc->num_attrs; i++) { |
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && |
|
(lc->attrs[i].mask & mask)) |
|
return lc->attrs[i].attr.flags; |
|
} |
|
return lc->flags; |
|
} |
|
|
|
static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, |
|
unsigned int line_idx) |
|
{ |
|
unsigned int i; |
|
u64 mask = BIT_ULL(line_idx); |
|
|
|
for (i = 0; i < lc->num_attrs; i++) { |
|
if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && |
|
(lc->attrs[i].mask & mask)) |
|
return !!(lc->attrs[i].attr.values & mask); |
|
} |
|
return 0; |
|
} |
|
|
|
static int gpio_v2_line_flags_validate(u64 flags) |
|
{ |
|
/* Return an error if an unknown flag is set */ |
|
if (flags & ~GPIO_V2_LINE_VALID_FLAGS) |
|
return -EINVAL; |
|
|
|
/* |
|
* Do not allow both INPUT and OUTPUT flags to be set as they are |
|
* contradictory. |
|
*/ |
|
if ((flags & GPIO_V2_LINE_FLAG_INPUT) && |
|
(flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
|
return -EINVAL; |
|
|
|
/* Edge detection requires explicit input. */ |
|
if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && |
|
!(flags & GPIO_V2_LINE_FLAG_INPUT)) |
|
return -EINVAL; |
|
|
|
/* |
|
* Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single |
|
* request. If the hardware actually supports enabling both at the |
|
* same time the electrical result would be disastrous. |
|
*/ |
|
if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && |
|
(flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) |
|
return -EINVAL; |
|
|
|
/* Drive requires explicit output direction. */ |
|
if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && |
|
!(flags & GPIO_V2_LINE_FLAG_OUTPUT)) |
|
return -EINVAL; |
|
|
|
/* Bias requires explicit direction. */ |
|
if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && |
|
!(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) |
|
return -EINVAL; |
|
|
|
/* Only one bias flag can be set. */ |
|
if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && |
|
(flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | |
|
GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || |
|
((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && |
|
(flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) |
|
return -EINVAL; |
|
|
|
return 0; |
|
} |
|
|
|
static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, |
|
unsigned int num_lines) |
|
{ |
|
unsigned int i; |
|
u64 flags; |
|
int ret; |
|
|
|
if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) |
|
return -EINVAL; |
|
|
|
if (memchr_inv(lc->padding, 0, sizeof(lc->padding))) |
|
return -EINVAL; |
|
|
|
for (i = 0; i < num_lines; i++) { |
|
flags = gpio_v2_line_config_flags(lc, i); |
|
ret = gpio_v2_line_flags_validate(flags); |
|
if (ret) |
|
return ret; |
|
|
|
/* debounce requires explicit input */ |
|
if (gpio_v2_line_config_debounced(lc, i) && |
|
!(flags & GPIO_V2_LINE_FLAG_INPUT)) |
|
return -EINVAL; |
|
} |
|
return 0; |
|
} |
|
|
|
static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, |
|
unsigned long *flagsp) |
|
{ |
|
assign_bit(FLAG_ACTIVE_LOW, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); |
|
|
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) |
|
set_bit(FLAG_IS_OUT, flagsp); |
|
else if (flags & GPIO_V2_LINE_FLAG_INPUT) |
|
clear_bit(FLAG_IS_OUT, flagsp); |
|
|
|
assign_bit(FLAG_EDGE_RISING, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_EDGE_RISING); |
|
assign_bit(FLAG_EDGE_FALLING, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_EDGE_FALLING); |
|
|
|
assign_bit(FLAG_OPEN_DRAIN, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); |
|
assign_bit(FLAG_OPEN_SOURCE, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); |
|
|
|
assign_bit(FLAG_PULL_UP, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); |
|
assign_bit(FLAG_PULL_DOWN, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); |
|
assign_bit(FLAG_BIAS_DISABLE, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); |
|
|
|
assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp, |
|
flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME); |
|
} |
|
|
|
static long linereq_get_values(struct linereq *lr, void __user *ip) |
|
{ |
|
struct gpio_v2_line_values lv; |
|
DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
|
struct gpio_desc **descs; |
|
unsigned int i, didx, num_get; |
|
bool val; |
|
int ret; |
|
|
|
/* NOTE: It's ok to read values of output lines. */ |
|
if (copy_from_user(&lv, ip, sizeof(lv))) |
|
return -EFAULT; |
|
|
|
for (num_get = 0, i = 0; i < lr->num_lines; i++) { |
|
if (lv.mask & BIT_ULL(i)) { |
|
num_get++; |
|
descs = &lr->lines[i].desc; |
|
} |
|
} |
|
|
|
if (num_get == 0) |
|
return -EINVAL; |
|
|
|
if (num_get != 1) { |
|
descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); |
|
if (!descs) |
|
return -ENOMEM; |
|
for (didx = 0, i = 0; i < lr->num_lines; i++) { |
|
if (lv.mask & BIT_ULL(i)) { |
|
descs[didx] = lr->lines[i].desc; |
|
didx++; |
|
} |
|
} |
|
} |
|
ret = gpiod_get_array_value_complex(false, true, num_get, |
|
descs, NULL, vals); |
|
|
|
if (num_get != 1) |
|
kfree(descs); |
|
if (ret) |
|
return ret; |
|
|
|
lv.bits = 0; |
|
for (didx = 0, i = 0; i < lr->num_lines; i++) { |
|
if (lv.mask & BIT_ULL(i)) { |
|
if (lr->lines[i].sw_debounced) |
|
val = debounced_value(&lr->lines[i]); |
|
else |
|
val = test_bit(didx, vals); |
|
if (val) |
|
lv.bits |= BIT_ULL(i); |
|
didx++; |
|
} |
|
} |
|
|
|
if (copy_to_user(ip, &lv, sizeof(lv))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
|
|
static long linereq_set_values_unlocked(struct linereq *lr, |
|
struct gpio_v2_line_values *lv) |
|
{ |
|
DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); |
|
struct gpio_desc **descs; |
|
unsigned int i, didx, num_set; |
|
int ret; |
|
|
|
bitmap_zero(vals, GPIO_V2_LINES_MAX); |
|
for (num_set = 0, i = 0; i < lr->num_lines; i++) { |
|
if (lv->mask & BIT_ULL(i)) { |
|
if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags)) |
|
return -EPERM; |
|
if (lv->bits & BIT_ULL(i)) |
|
__set_bit(num_set, vals); |
|
num_set++; |
|
descs = &lr->lines[i].desc; |
|
} |
|
} |
|
if (num_set == 0) |
|
return -EINVAL; |
|
|
|
if (num_set != 1) { |
|
/* build compacted desc array and values */ |
|
descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); |
|
if (!descs) |
|
return -ENOMEM; |
|
for (didx = 0, i = 0; i < lr->num_lines; i++) { |
|
if (lv->mask & BIT_ULL(i)) { |
|
descs[didx] = lr->lines[i].desc; |
|
didx++; |
|
} |
|
} |
|
} |
|
ret = gpiod_set_array_value_complex(false, true, num_set, |
|
descs, NULL, vals); |
|
|
|
if (num_set != 1) |
|
kfree(descs); |
|
return ret; |
|
} |
|
|
|
static long linereq_set_values(struct linereq *lr, void __user *ip) |
|
{ |
|
struct gpio_v2_line_values lv; |
|
int ret; |
|
|
|
if (copy_from_user(&lv, ip, sizeof(lv))) |
|
return -EFAULT; |
|
|
|
mutex_lock(&lr->config_mutex); |
|
|
|
ret = linereq_set_values_unlocked(lr, &lv); |
|
|
|
mutex_unlock(&lr->config_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static long linereq_set_config_unlocked(struct linereq *lr, |
|
struct gpio_v2_line_config *lc) |
|
{ |
|
struct gpio_desc *desc; |
|
unsigned int i; |
|
u64 flags; |
|
bool polarity_change; |
|
int ret; |
|
|
|
for (i = 0; i < lr->num_lines; i++) { |
|
desc = lr->lines[i].desc; |
|
flags = gpio_v2_line_config_flags(lc, i); |
|
polarity_change = |
|
(!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) != |
|
((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0)); |
|
|
|
gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); |
|
/* |
|
* Lines have to be requested explicitly for input |
|
* or output, else the line will be treated "as is". |
|
*/ |
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
|
int val = gpio_v2_line_config_output_value(lc, i); |
|
|
|
edge_detector_stop(&lr->lines[i]); |
|
ret = gpiod_direction_output(desc, val); |
|
if (ret) |
|
return ret; |
|
} else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
|
ret = gpiod_direction_input(desc); |
|
if (ret) |
|
return ret; |
|
|
|
ret = edge_detector_update(&lr->lines[i], lc, i, |
|
flags & GPIO_V2_LINE_EDGE_FLAGS, |
|
polarity_change); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier, |
|
GPIO_V2_LINE_CHANGED_CONFIG, |
|
desc); |
|
} |
|
return 0; |
|
} |
|
|
|
static long linereq_set_config(struct linereq *lr, void __user *ip) |
|
{ |
|
struct gpio_v2_line_config lc; |
|
int ret; |
|
|
|
if (copy_from_user(&lc, ip, sizeof(lc))) |
|
return -EFAULT; |
|
|
|
ret = gpio_v2_line_config_validate(&lc, lr->num_lines); |
|
if (ret) |
|
return ret; |
|
|
|
mutex_lock(&lr->config_mutex); |
|
|
|
ret = linereq_set_config_unlocked(lr, &lc); |
|
|
|
mutex_unlock(&lr->config_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static long linereq_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
struct linereq *lr = file->private_data; |
|
void __user *ip = (void __user *)arg; |
|
|
|
if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL) |
|
return linereq_get_values(lr, ip); |
|
else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL) |
|
return linereq_set_values(lr, ip); |
|
else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL) |
|
return linereq_set_config(lr, ip); |
|
|
|
return -EINVAL; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static long linereq_ioctl_compat(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
|
} |
|
#endif |
|
|
|
static __poll_t linereq_poll(struct file *file, |
|
struct poll_table_struct *wait) |
|
{ |
|
struct linereq *lr = file->private_data; |
|
__poll_t events = 0; |
|
|
|
poll_wait(file, &lr->wait, wait); |
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, |
|
&lr->wait.lock)) |
|
events = EPOLLIN | EPOLLRDNORM; |
|
|
|
return events; |
|
} |
|
|
|
static ssize_t linereq_read(struct file *file, |
|
char __user *buf, |
|
size_t count, |
|
loff_t *f_ps) |
|
{ |
|
struct linereq *lr = file->private_data; |
|
struct gpio_v2_line_event le; |
|
ssize_t bytes_read = 0; |
|
int ret; |
|
|
|
if (count < sizeof(le)) |
|
return -EINVAL; |
|
|
|
do { |
|
spin_lock(&lr->wait.lock); |
|
if (kfifo_is_empty(&lr->events)) { |
|
if (bytes_read) { |
|
spin_unlock(&lr->wait.lock); |
|
return bytes_read; |
|
} |
|
|
|
if (file->f_flags & O_NONBLOCK) { |
|
spin_unlock(&lr->wait.lock); |
|
return -EAGAIN; |
|
} |
|
|
|
ret = wait_event_interruptible_locked(lr->wait, |
|
!kfifo_is_empty(&lr->events)); |
|
if (ret) { |
|
spin_unlock(&lr->wait.lock); |
|
return ret; |
|
} |
|
} |
|
|
|
ret = kfifo_out(&lr->events, &le, 1); |
|
spin_unlock(&lr->wait.lock); |
|
if (ret != 1) { |
|
/* |
|
* This should never happen - we were holding the |
|
* lock from the moment we learned the fifo is no |
|
* longer empty until now. |
|
*/ |
|
ret = -EIO; |
|
break; |
|
} |
|
|
|
if (copy_to_user(buf + bytes_read, &le, sizeof(le))) |
|
return -EFAULT; |
|
bytes_read += sizeof(le); |
|
} while (count >= bytes_read + sizeof(le)); |
|
|
|
return bytes_read; |
|
} |
|
|
|
static void linereq_free(struct linereq *lr) |
|
{ |
|
unsigned int i; |
|
|
|
for (i = 0; i < lr->num_lines; i++) { |
|
edge_detector_stop(&lr->lines[i]); |
|
if (lr->lines[i].desc) |
|
gpiod_free(lr->lines[i].desc); |
|
} |
|
kfifo_free(&lr->events); |
|
kfree(lr->label); |
|
put_device(&lr->gdev->dev); |
|
kfree(lr); |
|
} |
|
|
|
static int linereq_release(struct inode *inode, struct file *file) |
|
{ |
|
struct linereq *lr = file->private_data; |
|
|
|
linereq_free(lr); |
|
return 0; |
|
} |
|
|
|
static const struct file_operations line_fileops = { |
|
.release = linereq_release, |
|
.read = linereq_read, |
|
.poll = linereq_poll, |
|
.owner = THIS_MODULE, |
|
.llseek = noop_llseek, |
|
.unlocked_ioctl = linereq_ioctl, |
|
#ifdef CONFIG_COMPAT |
|
.compat_ioctl = linereq_ioctl_compat, |
|
#endif |
|
}; |
|
|
|
static int linereq_create(struct gpio_device *gdev, void __user *ip) |
|
{ |
|
struct gpio_v2_line_request ulr; |
|
struct gpio_v2_line_config *lc; |
|
struct linereq *lr; |
|
struct file *file; |
|
u64 flags; |
|
unsigned int i; |
|
int fd, ret; |
|
|
|
if (copy_from_user(&ulr, ip, sizeof(ulr))) |
|
return -EFAULT; |
|
|
|
if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) |
|
return -EINVAL; |
|
|
|
if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding))) |
|
return -EINVAL; |
|
|
|
lc = &ulr.config; |
|
ret = gpio_v2_line_config_validate(lc, ulr.num_lines); |
|
if (ret) |
|
return ret; |
|
|
|
lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); |
|
if (!lr) |
|
return -ENOMEM; |
|
|
|
lr->gdev = gdev; |
|
get_device(&gdev->dev); |
|
|
|
for (i = 0; i < ulr.num_lines; i++) { |
|
lr->lines[i].req = lr; |
|
WRITE_ONCE(lr->lines[i].sw_debounced, 0); |
|
INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); |
|
} |
|
|
|
if (ulr.consumer[0] != '\0') { |
|
/* label is only initialized if consumer is set */ |
|
lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1, |
|
GFP_KERNEL); |
|
if (!lr->label) { |
|
ret = -ENOMEM; |
|
goto out_free_linereq; |
|
} |
|
} |
|
|
|
mutex_init(&lr->config_mutex); |
|
init_waitqueue_head(&lr->wait); |
|
lr->event_buffer_size = ulr.event_buffer_size; |
|
if (lr->event_buffer_size == 0) |
|
lr->event_buffer_size = ulr.num_lines * 16; |
|
else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) |
|
lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; |
|
|
|
atomic_set(&lr->seqno, 0); |
|
lr->num_lines = ulr.num_lines; |
|
|
|
/* Request each GPIO */ |
|
for (i = 0; i < ulr.num_lines; i++) { |
|
u32 offset = ulr.offsets[i]; |
|
struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); |
|
|
|
if (IS_ERR(desc)) { |
|
ret = PTR_ERR(desc); |
|
goto out_free_linereq; |
|
} |
|
|
|
ret = gpiod_request(desc, lr->label); |
|
if (ret) |
|
goto out_free_linereq; |
|
|
|
lr->lines[i].desc = desc; |
|
flags = gpio_v2_line_config_flags(lc, i); |
|
gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); |
|
|
|
ret = gpiod_set_transitory(desc, false); |
|
if (ret < 0) |
|
goto out_free_linereq; |
|
|
|
/* |
|
* Lines have to be requested explicitly for input |
|
* or output, else the line will be treated "as is". |
|
*/ |
|
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { |
|
int val = gpio_v2_line_config_output_value(lc, i); |
|
|
|
ret = gpiod_direction_output(desc, val); |
|
if (ret) |
|
goto out_free_linereq; |
|
} else if (flags & GPIO_V2_LINE_FLAG_INPUT) { |
|
ret = gpiod_direction_input(desc); |
|
if (ret) |
|
goto out_free_linereq; |
|
|
|
ret = edge_detector_setup(&lr->lines[i], lc, i, |
|
flags & GPIO_V2_LINE_EDGE_FLAGS); |
|
if (ret) |
|
goto out_free_linereq; |
|
} |
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier, |
|
GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
|
|
|
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", |
|
offset); |
|
} |
|
|
|
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
|
if (fd < 0) { |
|
ret = fd; |
|
goto out_free_linereq; |
|
} |
|
|
|
file = anon_inode_getfile("gpio-line", &line_fileops, lr, |
|
O_RDONLY | O_CLOEXEC); |
|
if (IS_ERR(file)) { |
|
ret = PTR_ERR(file); |
|
goto out_put_unused_fd; |
|
} |
|
|
|
ulr.fd = fd; |
|
if (copy_to_user(ip, &ulr, sizeof(ulr))) { |
|
/* |
|
* fput() will trigger the release() callback, so do not go onto |
|
* the regular error cleanup path here. |
|
*/ |
|
fput(file); |
|
put_unused_fd(fd); |
|
return -EFAULT; |
|
} |
|
|
|
fd_install(fd, file); |
|
|
|
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", |
|
lr->num_lines); |
|
|
|
return 0; |
|
|
|
out_put_unused_fd: |
|
put_unused_fd(fd); |
|
out_free_linereq: |
|
linereq_free(lr); |
|
return ret; |
|
} |
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
|
|
/* |
|
* GPIO line event management |
|
*/ |
|
|
|
/** |
|
* struct lineevent_state - contains the state of a userspace event |
|
* @gdev: the GPIO device the event pertains to |
|
* @label: consumer label used to tag descriptors |
|
* @desc: the GPIO descriptor held by this event |
|
* @eflags: the event flags this line was requested with |
|
* @irq: the interrupt that trigger in response to events on this GPIO |
|
* @wait: wait queue that handles blocking reads of events |
|
* @events: KFIFO for the GPIO events |
|
* @timestamp: cache for the timestamp storing it between hardirq |
|
* and IRQ thread, used to bring the timestamp close to the actual |
|
* event |
|
*/ |
|
struct lineevent_state { |
|
struct gpio_device *gdev; |
|
const char *label; |
|
struct gpio_desc *desc; |
|
u32 eflags; |
|
int irq; |
|
wait_queue_head_t wait; |
|
DECLARE_KFIFO(events, struct gpioevent_data, 16); |
|
u64 timestamp; |
|
}; |
|
|
|
#define GPIOEVENT_REQUEST_VALID_FLAGS \ |
|
(GPIOEVENT_REQUEST_RISING_EDGE | \ |
|
GPIOEVENT_REQUEST_FALLING_EDGE) |
|
|
|
static __poll_t lineevent_poll(struct file *file, |
|
struct poll_table_struct *wait) |
|
{ |
|
struct lineevent_state *le = file->private_data; |
|
__poll_t events = 0; |
|
|
|
poll_wait(file, &le->wait, wait); |
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) |
|
events = EPOLLIN | EPOLLRDNORM; |
|
|
|
return events; |
|
} |
|
|
|
struct compat_gpioeevent_data { |
|
compat_u64 timestamp; |
|
u32 id; |
|
}; |
|
|
|
static ssize_t lineevent_read(struct file *file, |
|
char __user *buf, |
|
size_t count, |
|
loff_t *f_ps) |
|
{ |
|
struct lineevent_state *le = file->private_data; |
|
struct gpioevent_data ge; |
|
ssize_t bytes_read = 0; |
|
ssize_t ge_size; |
|
int ret; |
|
|
|
/* |
|
* When compatible system call is being used the struct gpioevent_data, |
|
* in case of at least ia32, has different size due to the alignment |
|
* differences. Because we have first member 64 bits followed by one of |
|
* 32 bits there is no gap between them. The only difference is the |
|
* padding at the end of the data structure. Hence, we calculate the |
|
* actual sizeof() and pass this as an argument to copy_to_user() to |
|
* drop unneeded bytes from the output. |
|
*/ |
|
if (compat_need_64bit_alignment_fixup()) |
|
ge_size = sizeof(struct compat_gpioeevent_data); |
|
else |
|
ge_size = sizeof(struct gpioevent_data); |
|
if (count < ge_size) |
|
return -EINVAL; |
|
|
|
do { |
|
spin_lock(&le->wait.lock); |
|
if (kfifo_is_empty(&le->events)) { |
|
if (bytes_read) { |
|
spin_unlock(&le->wait.lock); |
|
return bytes_read; |
|
} |
|
|
|
if (file->f_flags & O_NONBLOCK) { |
|
spin_unlock(&le->wait.lock); |
|
return -EAGAIN; |
|
} |
|
|
|
ret = wait_event_interruptible_locked(le->wait, |
|
!kfifo_is_empty(&le->events)); |
|
if (ret) { |
|
spin_unlock(&le->wait.lock); |
|
return ret; |
|
} |
|
} |
|
|
|
ret = kfifo_out(&le->events, &ge, 1); |
|
spin_unlock(&le->wait.lock); |
|
if (ret != 1) { |
|
/* |
|
* This should never happen - we were holding the lock |
|
* from the moment we learned the fifo is no longer |
|
* empty until now. |
|
*/ |
|
ret = -EIO; |
|
break; |
|
} |
|
|
|
if (copy_to_user(buf + bytes_read, &ge, ge_size)) |
|
return -EFAULT; |
|
bytes_read += ge_size; |
|
} while (count >= bytes_read + ge_size); |
|
|
|
return bytes_read; |
|
} |
|
|
|
static void lineevent_free(struct lineevent_state *le) |
|
{ |
|
if (le->irq) |
|
free_irq(le->irq, le); |
|
if (le->desc) |
|
gpiod_free(le->desc); |
|
kfree(le->label); |
|
put_device(&le->gdev->dev); |
|
kfree(le); |
|
} |
|
|
|
static int lineevent_release(struct inode *inode, struct file *file) |
|
{ |
|
lineevent_free(file->private_data); |
|
return 0; |
|
} |
|
|
|
static long lineevent_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
struct lineevent_state *le = file->private_data; |
|
void __user *ip = (void __user *)arg; |
|
struct gpiohandle_data ghd; |
|
|
|
/* |
|
* We can get the value for an event line but not set it, |
|
* because it is input by definition. |
|
*/ |
|
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { |
|
int val; |
|
|
|
memset(&ghd, 0, sizeof(ghd)); |
|
|
|
val = gpiod_get_value_cansleep(le->desc); |
|
if (val < 0) |
|
return val; |
|
ghd.values[0] = val; |
|
|
|
if (copy_to_user(ip, &ghd, sizeof(ghd))) |
|
return -EFAULT; |
|
|
|
return 0; |
|
} |
|
return -EINVAL; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
return lineevent_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
|
} |
|
#endif |
|
|
|
static const struct file_operations lineevent_fileops = { |
|
.release = lineevent_release, |
|
.read = lineevent_read, |
|
.poll = lineevent_poll, |
|
.owner = THIS_MODULE, |
|
.llseek = noop_llseek, |
|
.unlocked_ioctl = lineevent_ioctl, |
|
#ifdef CONFIG_COMPAT |
|
.compat_ioctl = lineevent_ioctl_compat, |
|
#endif |
|
}; |
|
|
|
static irqreturn_t lineevent_irq_thread(int irq, void *p) |
|
{ |
|
struct lineevent_state *le = p; |
|
struct gpioevent_data ge; |
|
int ret; |
|
|
|
/* Do not leak kernel stack to userspace */ |
|
memset(&ge, 0, sizeof(ge)); |
|
|
|
/* |
|
* We may be running from a nested threaded interrupt in which case |
|
* we didn't get the timestamp from lineevent_irq_handler(). |
|
*/ |
|
if (!le->timestamp) |
|
ge.timestamp = ktime_get_ns(); |
|
else |
|
ge.timestamp = le->timestamp; |
|
|
|
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE |
|
&& le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { |
|
int level = gpiod_get_value_cansleep(le->desc); |
|
|
|
if (level) |
|
/* Emit low-to-high event */ |
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE; |
|
else |
|
/* Emit high-to-low event */ |
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE; |
|
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { |
|
/* Emit low-to-high event */ |
|
ge.id = GPIOEVENT_EVENT_RISING_EDGE; |
|
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { |
|
/* Emit high-to-low event */ |
|
ge.id = GPIOEVENT_EVENT_FALLING_EDGE; |
|
} else { |
|
return IRQ_NONE; |
|
} |
|
|
|
ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, |
|
1, &le->wait.lock); |
|
if (ret) |
|
wake_up_poll(&le->wait, EPOLLIN); |
|
else |
|
pr_debug_ratelimited("event FIFO is full - event dropped\n"); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static irqreturn_t lineevent_irq_handler(int irq, void *p) |
|
{ |
|
struct lineevent_state *le = p; |
|
|
|
/* |
|
* Just store the timestamp in hardirq context so we get it as |
|
* close in time as possible to the actual event. |
|
*/ |
|
le->timestamp = ktime_get_ns(); |
|
|
|
return IRQ_WAKE_THREAD; |
|
} |
|
|
|
static int lineevent_create(struct gpio_device *gdev, void __user *ip) |
|
{ |
|
struct gpioevent_request eventreq; |
|
struct lineevent_state *le; |
|
struct gpio_desc *desc; |
|
struct file *file; |
|
u32 offset; |
|
u32 lflags; |
|
u32 eflags; |
|
int fd; |
|
int ret; |
|
int irq, irqflags = 0; |
|
|
|
if (copy_from_user(&eventreq, ip, sizeof(eventreq))) |
|
return -EFAULT; |
|
|
|
offset = eventreq.lineoffset; |
|
lflags = eventreq.handleflags; |
|
eflags = eventreq.eventflags; |
|
|
|
desc = gpiochip_get_desc(gdev->chip, offset); |
|
if (IS_ERR(desc)) |
|
return PTR_ERR(desc); |
|
|
|
/* Return an error if a unknown flag is set */ |
|
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || |
|
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) |
|
return -EINVAL; |
|
|
|
/* This is just wrong: we don't look for events on output lines */ |
|
if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || |
|
(lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || |
|
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) |
|
return -EINVAL; |
|
|
|
/* Only one bias flag can be set. */ |
|
if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && |
|
(lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | |
|
GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || |
|
((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && |
|
(lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) |
|
return -EINVAL; |
|
|
|
le = kzalloc(sizeof(*le), GFP_KERNEL); |
|
if (!le) |
|
return -ENOMEM; |
|
le->gdev = gdev; |
|
get_device(&gdev->dev); |
|
|
|
if (eventreq.consumer_label[0] != '\0') { |
|
/* label is only initialized if consumer_label is set */ |
|
le->label = kstrndup(eventreq.consumer_label, |
|
sizeof(eventreq.consumer_label) - 1, |
|
GFP_KERNEL); |
|
if (!le->label) { |
|
ret = -ENOMEM; |
|
goto out_free_le; |
|
} |
|
} |
|
|
|
ret = gpiod_request(desc, le->label); |
|
if (ret) |
|
goto out_free_le; |
|
le->desc = desc; |
|
le->eflags = eflags; |
|
|
|
linehandle_flags_to_desc_flags(lflags, &desc->flags); |
|
|
|
ret = gpiod_direction_input(desc); |
|
if (ret) |
|
goto out_free_le; |
|
|
|
blocking_notifier_call_chain(&desc->gdev->notifier, |
|
GPIO_V2_LINE_CHANGED_REQUESTED, desc); |
|
|
|
irq = gpiod_to_irq(desc); |
|
if (irq <= 0) { |
|
ret = -ENODEV; |
|
goto out_free_le; |
|
} |
|
le->irq = irq; |
|
|
|
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) |
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
|
IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; |
|
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) |
|
irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? |
|
IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; |
|
irqflags |= IRQF_ONESHOT; |
|
|
|
INIT_KFIFO(le->events); |
|
init_waitqueue_head(&le->wait); |
|
|
|
/* Request a thread to read the events */ |
|
ret = request_threaded_irq(le->irq, |
|
lineevent_irq_handler, |
|
lineevent_irq_thread, |
|
irqflags, |
|
le->label, |
|
le); |
|
if (ret) |
|
goto out_free_le; |
|
|
|
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); |
|
if (fd < 0) { |
|
ret = fd; |
|
goto out_free_le; |
|
} |
|
|
|
file = anon_inode_getfile("gpio-event", |
|
&lineevent_fileops, |
|
le, |
|
O_RDONLY | O_CLOEXEC); |
|
if (IS_ERR(file)) { |
|
ret = PTR_ERR(file); |
|
goto out_put_unused_fd; |
|
} |
|
|
|
eventreq.fd = fd; |
|
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { |
|
/* |
|
* fput() will trigger the release() callback, so do not go onto |
|
* the regular error cleanup path here. |
|
*/ |
|
fput(file); |
|
put_unused_fd(fd); |
|
return -EFAULT; |
|
} |
|
|
|
fd_install(fd, file); |
|
|
|
return 0; |
|
|
|
out_put_unused_fd: |
|
put_unused_fd(fd); |
|
out_free_le: |
|
lineevent_free(le); |
|
return ret; |
|
} |
|
|
|
static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, |
|
struct gpioline_info *info_v1) |
|
{ |
|
u64 flagsv2 = info_v2->flags; |
|
|
|
memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); |
|
memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); |
|
info_v1->line_offset = info_v2->offset; |
|
info_v1->flags = 0; |
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_USED) |
|
info_v1->flags |= GPIOLINE_FLAG_KERNEL; |
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) |
|
info_v1->flags |= GPIOLINE_FLAG_IS_OUT; |
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) |
|
info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; |
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) |
|
info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; |
|
if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) |
|
info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; |
|
|
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) |
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; |
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) |
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; |
|
if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) |
|
info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; |
|
} |
|
|
|
static void gpio_v2_line_info_changed_to_v1( |
|
struct gpio_v2_line_info_changed *lic_v2, |
|
struct gpioline_info_changed *lic_v1) |
|
{ |
|
memset(lic_v1, 0, sizeof(*lic_v1)); |
|
gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info); |
|
lic_v1->timestamp = lic_v2->timestamp_ns; |
|
lic_v1->event_type = lic_v2->event_type; |
|
} |
|
|
|
#endif /* CONFIG_GPIO_CDEV_V1 */ |
|
|
|
static void gpio_desc_to_lineinfo(struct gpio_desc *desc, |
|
struct gpio_v2_line_info *info) |
|
{ |
|
struct gpio_chip *gc = desc->gdev->chip; |
|
bool ok_for_pinctrl; |
|
unsigned long flags; |
|
u32 debounce_period_us; |
|
unsigned int num_attrs = 0; |
|
|
|
memset(info, 0, sizeof(*info)); |
|
info->offset = gpio_chip_hwgpio(desc); |
|
|
|
/* |
|
* This function takes a mutex so we must check this before taking |
|
* the spinlock. |
|
* |
|
* FIXME: find a non-racy way to retrieve this information. Maybe a |
|
* lock common to both frameworks? |
|
*/ |
|
ok_for_pinctrl = |
|
pinctrl_gpio_can_use_line(gc->base + info->offset); |
|
|
|
spin_lock_irqsave(&gpio_lock, flags); |
|
|
|
if (desc->name) |
|
strscpy(info->name, desc->name, sizeof(info->name)); |
|
|
|
if (desc->label) |
|
strscpy(info->consumer, desc->label, sizeof(info->consumer)); |
|
|
|
/* |
|
* Userspace only need to know that the kernel is using this GPIO so |
|
* it can't use it. |
|
*/ |
|
info->flags = 0; |
|
if (test_bit(FLAG_REQUESTED, &desc->flags) || |
|
test_bit(FLAG_IS_HOGGED, &desc->flags) || |
|
test_bit(FLAG_USED_AS_IRQ, &desc->flags) || |
|
test_bit(FLAG_EXPORT, &desc->flags) || |
|
test_bit(FLAG_SYSFS, &desc->flags) || |
|
!gpiochip_line_is_valid(gc, info->offset) || |
|
!ok_for_pinctrl) |
|
info->flags |= GPIO_V2_LINE_FLAG_USED; |
|
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; |
|
else |
|
info->flags |= GPIO_V2_LINE_FLAG_INPUT; |
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; |
|
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; |
|
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; |
|
|
|
if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; |
|
if (test_bit(FLAG_PULL_DOWN, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; |
|
if (test_bit(FLAG_PULL_UP, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; |
|
|
|
if (test_bit(FLAG_EDGE_RISING, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; |
|
if (test_bit(FLAG_EDGE_FALLING, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; |
|
|
|
if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags)) |
|
info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME; |
|
|
|
debounce_period_us = READ_ONCE(desc->debounce_period_us); |
|
if (debounce_period_us) { |
|
info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; |
|
info->attrs[num_attrs].debounce_period_us = debounce_period_us; |
|
num_attrs++; |
|
} |
|
info->num_attrs = num_attrs; |
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags); |
|
} |
|
|
|
struct gpio_chardev_data { |
|
struct gpio_device *gdev; |
|
wait_queue_head_t wait; |
|
DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); |
|
struct notifier_block lineinfo_changed_nb; |
|
unsigned long *watched_lines; |
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
atomic_t watch_abi_version; |
|
#endif |
|
}; |
|
|
|
static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) |
|
{ |
|
struct gpio_device *gdev = cdev->gdev; |
|
struct gpiochip_info chipinfo; |
|
|
|
memset(&chipinfo, 0, sizeof(chipinfo)); |
|
|
|
strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); |
|
strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); |
|
chipinfo.lines = gdev->ngpio; |
|
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
/* |
|
* returns 0 if the versions match, else the previously selected ABI version |
|
*/ |
|
static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, |
|
unsigned int version) |
|
{ |
|
int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); |
|
|
|
if (abiv == version) |
|
return 0; |
|
|
|
return abiv; |
|
} |
|
|
|
static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, |
|
bool watch) |
|
{ |
|
struct gpio_desc *desc; |
|
struct gpioline_info lineinfo; |
|
struct gpio_v2_line_info lineinfo_v2; |
|
|
|
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) |
|
return -EFAULT; |
|
|
|
/* this doubles as a range check on line_offset */ |
|
desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset); |
|
if (IS_ERR(desc)) |
|
return PTR_ERR(desc); |
|
|
|
if (watch) { |
|
if (lineinfo_ensure_abi_version(cdev, 1)) |
|
return -EPERM; |
|
|
|
if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) |
|
return -EBUSY; |
|
} |
|
|
|
gpio_desc_to_lineinfo(desc, &lineinfo_v2); |
|
gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); |
|
|
|
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { |
|
if (watch) |
|
clear_bit(lineinfo.line_offset, cdev->watched_lines); |
|
return -EFAULT; |
|
} |
|
|
|
return 0; |
|
} |
|
#endif |
|
|
|
static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, |
|
bool watch) |
|
{ |
|
struct gpio_desc *desc; |
|
struct gpio_v2_line_info lineinfo; |
|
|
|
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) |
|
return -EFAULT; |
|
|
|
if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding))) |
|
return -EINVAL; |
|
|
|
desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset); |
|
if (IS_ERR(desc)) |
|
return PTR_ERR(desc); |
|
|
|
if (watch) { |
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
if (lineinfo_ensure_abi_version(cdev, 2)) |
|
return -EPERM; |
|
#endif |
|
if (test_and_set_bit(lineinfo.offset, cdev->watched_lines)) |
|
return -EBUSY; |
|
} |
|
gpio_desc_to_lineinfo(desc, &lineinfo); |
|
|
|
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { |
|
if (watch) |
|
clear_bit(lineinfo.offset, cdev->watched_lines); |
|
return -EFAULT; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) |
|
{ |
|
__u32 offset; |
|
|
|
if (copy_from_user(&offset, ip, sizeof(offset))) |
|
return -EFAULT; |
|
|
|
if (offset >= cdev->gdev->ngpio) |
|
return -EINVAL; |
|
|
|
if (!test_and_clear_bit(offset, cdev->watched_lines)) |
|
return -EBUSY; |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* gpio_ioctl() - ioctl handler for the GPIO chardev |
|
*/ |
|
static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
|
{ |
|
struct gpio_chardev_data *cdev = file->private_data; |
|
struct gpio_device *gdev = cdev->gdev; |
|
void __user *ip = (void __user *)arg; |
|
|
|
/* We fail any subsequent ioctl():s when the chip is gone */ |
|
if (!gdev->chip) |
|
return -ENODEV; |
|
|
|
/* Fill in the struct and pass to userspace */ |
|
if (cmd == GPIO_GET_CHIPINFO_IOCTL) { |
|
return chipinfo_get(cdev, ip); |
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { |
|
return linehandle_create(gdev, ip); |
|
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { |
|
return lineevent_create(gdev, ip); |
|
} else if (cmd == GPIO_GET_LINEINFO_IOCTL || |
|
cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { |
|
return lineinfo_get_v1(cdev, ip, |
|
cmd == GPIO_GET_LINEINFO_WATCH_IOCTL); |
|
#endif /* CONFIG_GPIO_CDEV_V1 */ |
|
} else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL || |
|
cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) { |
|
return lineinfo_get(cdev, ip, |
|
cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL); |
|
} else if (cmd == GPIO_V2_GET_LINE_IOCTL) { |
|
return linereq_create(gdev, ip); |
|
} else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { |
|
return lineinfo_unwatch(cdev, ip); |
|
} |
|
return -EINVAL; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
static long gpio_ioctl_compat(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
return gpio_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
|
} |
|
#endif |
|
|
|
static struct gpio_chardev_data * |
|
to_gpio_chardev_data(struct notifier_block *nb) |
|
{ |
|
return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); |
|
} |
|
|
|
static int lineinfo_changed_notify(struct notifier_block *nb, |
|
unsigned long action, void *data) |
|
{ |
|
struct gpio_chardev_data *cdev = to_gpio_chardev_data(nb); |
|
struct gpio_v2_line_info_changed chg; |
|
struct gpio_desc *desc = data; |
|
int ret; |
|
|
|
if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines)) |
|
return NOTIFY_DONE; |
|
|
|
memset(&chg, 0, sizeof(chg)); |
|
chg.event_type = action; |
|
chg.timestamp_ns = ktime_get_ns(); |
|
gpio_desc_to_lineinfo(desc, &chg.info); |
|
|
|
ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock); |
|
if (ret) |
|
wake_up_poll(&cdev->wait, EPOLLIN); |
|
else |
|
pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); |
|
|
|
return NOTIFY_OK; |
|
} |
|
|
|
static __poll_t lineinfo_watch_poll(struct file *file, |
|
struct poll_table_struct *pollt) |
|
{ |
|
struct gpio_chardev_data *cdev = file->private_data; |
|
__poll_t events = 0; |
|
|
|
poll_wait(file, &cdev->wait, pollt); |
|
|
|
if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, |
|
&cdev->wait.lock)) |
|
events = EPOLLIN | EPOLLRDNORM; |
|
|
|
return events; |
|
} |
|
|
|
static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, |
|
size_t count, loff_t *off) |
|
{ |
|
struct gpio_chardev_data *cdev = file->private_data; |
|
struct gpio_v2_line_info_changed event; |
|
ssize_t bytes_read = 0; |
|
int ret; |
|
size_t event_size; |
|
|
|
#ifndef CONFIG_GPIO_CDEV_V1 |
|
event_size = sizeof(struct gpio_v2_line_info_changed); |
|
if (count < event_size) |
|
return -EINVAL; |
|
#endif |
|
|
|
do { |
|
spin_lock(&cdev->wait.lock); |
|
if (kfifo_is_empty(&cdev->events)) { |
|
if (bytes_read) { |
|
spin_unlock(&cdev->wait.lock); |
|
return bytes_read; |
|
} |
|
|
|
if (file->f_flags & O_NONBLOCK) { |
|
spin_unlock(&cdev->wait.lock); |
|
return -EAGAIN; |
|
} |
|
|
|
ret = wait_event_interruptible_locked(cdev->wait, |
|
!kfifo_is_empty(&cdev->events)); |
|
if (ret) { |
|
spin_unlock(&cdev->wait.lock); |
|
return ret; |
|
} |
|
} |
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
/* must be after kfifo check so watch_abi_version is set */ |
|
if (atomic_read(&cdev->watch_abi_version) == 2) |
|
event_size = sizeof(struct gpio_v2_line_info_changed); |
|
else |
|
event_size = sizeof(struct gpioline_info_changed); |
|
if (count < event_size) { |
|
spin_unlock(&cdev->wait.lock); |
|
return -EINVAL; |
|
} |
|
#endif |
|
ret = kfifo_out(&cdev->events, &event, 1); |
|
spin_unlock(&cdev->wait.lock); |
|
if (ret != 1) { |
|
ret = -EIO; |
|
break; |
|
/* We should never get here. See lineevent_read(). */ |
|
} |
|
|
|
#ifdef CONFIG_GPIO_CDEV_V1 |
|
if (event_size == sizeof(struct gpio_v2_line_info_changed)) { |
|
if (copy_to_user(buf + bytes_read, &event, event_size)) |
|
return -EFAULT; |
|
} else { |
|
struct gpioline_info_changed event_v1; |
|
|
|
gpio_v2_line_info_changed_to_v1(&event, &event_v1); |
|
if (copy_to_user(buf + bytes_read, &event_v1, |
|
event_size)) |
|
return -EFAULT; |
|
} |
|
#else |
|
if (copy_to_user(buf + bytes_read, &event, event_size)) |
|
return -EFAULT; |
|
#endif |
|
bytes_read += event_size; |
|
} while (count >= bytes_read + sizeof(event)); |
|
|
|
return bytes_read; |
|
} |
|
|
|
/** |
|
* gpio_chrdev_open() - open the chardev for ioctl operations |
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* @inode: inode for this chardev |
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* @file: file struct for storing private data |
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* Returns 0 on success |
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*/ |
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static int gpio_chrdev_open(struct inode *inode, struct file *file) |
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{ |
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struct gpio_device *gdev = container_of(inode->i_cdev, |
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struct gpio_device, chrdev); |
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struct gpio_chardev_data *cdev; |
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int ret = -ENOMEM; |
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/* Fail on open if the backing gpiochip is gone */ |
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if (!gdev->chip) |
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return -ENODEV; |
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cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); |
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if (!cdev) |
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return -ENOMEM; |
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cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); |
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if (!cdev->watched_lines) |
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goto out_free_cdev; |
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init_waitqueue_head(&cdev->wait); |
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INIT_KFIFO(cdev->events); |
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cdev->gdev = gdev; |
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|
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cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; |
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ret = blocking_notifier_chain_register(&gdev->notifier, |
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&cdev->lineinfo_changed_nb); |
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if (ret) |
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goto out_free_bitmap; |
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|
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get_device(&gdev->dev); |
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file->private_data = cdev; |
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|
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ret = nonseekable_open(inode, file); |
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if (ret) |
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goto out_unregister_notifier; |
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return ret; |
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out_unregister_notifier: |
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blocking_notifier_chain_unregister(&gdev->notifier, |
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&cdev->lineinfo_changed_nb); |
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out_free_bitmap: |
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bitmap_free(cdev->watched_lines); |
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out_free_cdev: |
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kfree(cdev); |
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return ret; |
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} |
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|
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/** |
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* gpio_chrdev_release() - close chardev after ioctl operations |
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* @inode: inode for this chardev |
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* @file: file struct for storing private data |
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* Returns 0 on success |
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*/ |
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static int gpio_chrdev_release(struct inode *inode, struct file *file) |
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{ |
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struct gpio_chardev_data *cdev = file->private_data; |
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struct gpio_device *gdev = cdev->gdev; |
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|
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bitmap_free(cdev->watched_lines); |
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blocking_notifier_chain_unregister(&gdev->notifier, |
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&cdev->lineinfo_changed_nb); |
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put_device(&gdev->dev); |
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kfree(cdev); |
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|
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return 0; |
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} |
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|
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static const struct file_operations gpio_fileops = { |
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.release = gpio_chrdev_release, |
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.open = gpio_chrdev_open, |
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.poll = lineinfo_watch_poll, |
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.read = lineinfo_watch_read, |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.unlocked_ioctl = gpio_ioctl, |
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#ifdef CONFIG_COMPAT |
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.compat_ioctl = gpio_ioctl_compat, |
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#endif |
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}; |
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|
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int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) |
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{ |
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int ret; |
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|
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cdev_init(&gdev->chrdev, &gpio_fileops); |
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gdev->chrdev.owner = THIS_MODULE; |
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gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); |
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|
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ret = cdev_device_add(&gdev->chrdev, &gdev->dev); |
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if (ret) |
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return ret; |
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|
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chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", |
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MAJOR(devt), gdev->id); |
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|
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return 0; |
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} |
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|
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void gpiolib_cdev_unregister(struct gpio_device *gdev) |
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{ |
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cdev_device_del(&gdev->chrdev, &gdev->dev); |
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}
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