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774 lines
19 KiB
774 lines
19 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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i2c-dev.c - i2c-bus driver, char device interface |
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|
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Copyright (C) 1995-97 Simon G. Vogl |
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Copyright (C) 1998-99 Frodo Looijaard <[email protected]> |
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Copyright (C) 2003 Greg Kroah-Hartman <[email protected]> |
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*/ |
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|
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/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. |
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But I have used so much of his original code and ideas that it seems |
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only fair to recognize him as co-author -- Frodo */ |
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|
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/* The I2C_RDWR ioctl code is written by Kolja Waschk <[email protected]> */ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/cdev.h> |
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#include <linux/compat.h> |
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#include <linux/device.h> |
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#include <linux/fs.h> |
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#include <linux/i2c-dev.h> |
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#include <linux/i2c.h> |
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#include <linux/init.h> |
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#include <linux/jiffies.h> |
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#include <linux/kernel.h> |
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#include <linux/list.h> |
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#include <linux/module.h> |
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#include <linux/notifier.h> |
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#include <linux/slab.h> |
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#include <linux/uaccess.h> |
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|
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/* |
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* An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a |
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* slave (i2c_client) with which messages will be exchanged. It's coupled |
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* with a character special file which is accessed by user mode drivers. |
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* |
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* The list of i2c_dev structures is parallel to the i2c_adapter lists |
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* maintained by the driver model, and is updated using bus notifications. |
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*/ |
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struct i2c_dev { |
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struct list_head list; |
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struct i2c_adapter *adap; |
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struct device dev; |
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struct cdev cdev; |
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}; |
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#define I2C_MINORS (MINORMASK + 1) |
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static LIST_HEAD(i2c_dev_list); |
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static DEFINE_SPINLOCK(i2c_dev_list_lock); |
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static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) |
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{ |
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struct i2c_dev *i2c_dev; |
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spin_lock(&i2c_dev_list_lock); |
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list_for_each_entry(i2c_dev, &i2c_dev_list, list) { |
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if (i2c_dev->adap->nr == index) |
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goto found; |
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} |
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i2c_dev = NULL; |
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found: |
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spin_unlock(&i2c_dev_list_lock); |
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return i2c_dev; |
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} |
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static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
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{ |
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struct i2c_dev *i2c_dev; |
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if (adap->nr >= I2C_MINORS) { |
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pr_err("Out of device minors (%d)\n", adap->nr); |
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return ERR_PTR(-ENODEV); |
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} |
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i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
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if (!i2c_dev) |
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return ERR_PTR(-ENOMEM); |
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i2c_dev->adap = adap; |
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spin_lock(&i2c_dev_list_lock); |
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list_add_tail(&i2c_dev->list, &i2c_dev_list); |
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spin_unlock(&i2c_dev_list_lock); |
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return i2c_dev; |
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} |
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static void put_i2c_dev(struct i2c_dev *i2c_dev, bool del_cdev) |
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{ |
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spin_lock(&i2c_dev_list_lock); |
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list_del(&i2c_dev->list); |
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spin_unlock(&i2c_dev_list_lock); |
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if (del_cdev) |
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cdev_device_del(&i2c_dev->cdev, &i2c_dev->dev); |
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put_device(&i2c_dev->dev); |
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} |
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static ssize_t name_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
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if (!i2c_dev) |
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return -ENODEV; |
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return sysfs_emit(buf, "%s\n", i2c_dev->adap->name); |
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} |
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static DEVICE_ATTR_RO(name); |
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static struct attribute *i2c_attrs[] = { |
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&dev_attr_name.attr, |
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NULL, |
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}; |
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ATTRIBUTE_GROUPS(i2c); |
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|
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/* ------------------------------------------------------------------------- */ |
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/* |
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* After opening an instance of this character special file, a file |
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* descriptor starts out associated only with an i2c_adapter (and bus). |
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* |
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* Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg |
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* traffic to any devices on the bus used by that adapter. That's because |
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* the i2c_msg vectors embed all the addressing information they need, and |
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* are submitted directly to an i2c_adapter. However, SMBus-only adapters |
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* don't support that interface. |
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* |
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* To use read()/write() system calls on that file descriptor, or to use |
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* SMBus interfaces (and work with SMBus-only hosts!), you must first issue |
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* an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous |
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* (never registered) i2c_client so it holds the addressing information |
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* needed by those system calls and by this SMBus interface. |
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*/ |
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static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
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loff_t *offset) |
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{ |
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char *tmp; |
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int ret; |
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struct i2c_client *client = file->private_data; |
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if (count > 8192) |
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count = 8192; |
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tmp = kzalloc(count, GFP_KERNEL); |
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if (tmp == NULL) |
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return -ENOMEM; |
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pr_debug("i2c-%d reading %zu bytes.\n", iminor(file_inode(file)), count); |
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ret = i2c_master_recv(client, tmp, count); |
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if (ret >= 0) |
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if (copy_to_user(buf, tmp, ret)) |
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ret = -EFAULT; |
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kfree(tmp); |
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return ret; |
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} |
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static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
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size_t count, loff_t *offset) |
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{ |
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int ret; |
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char *tmp; |
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struct i2c_client *client = file->private_data; |
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if (count > 8192) |
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count = 8192; |
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tmp = memdup_user(buf, count); |
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if (IS_ERR(tmp)) |
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return PTR_ERR(tmp); |
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pr_debug("i2c-%d writing %zu bytes.\n", iminor(file_inode(file)), count); |
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ret = i2c_master_send(client, tmp, count); |
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kfree(tmp); |
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return ret; |
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} |
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static int i2cdev_check(struct device *dev, void *addrp) |
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{ |
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struct i2c_client *client = i2c_verify_client(dev); |
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if (!client || client->addr != *(unsigned int *)addrp) |
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return 0; |
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return dev->driver ? -EBUSY : 0; |
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} |
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/* walk up mux tree */ |
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static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) |
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{ |
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struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
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int result; |
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result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); |
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if (!result && parent) |
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result = i2cdev_check_mux_parents(parent, addr); |
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return result; |
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} |
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/* recurse down mux tree */ |
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static int i2cdev_check_mux_children(struct device *dev, void *addrp) |
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{ |
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int result; |
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if (dev->type == &i2c_adapter_type) |
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result = device_for_each_child(dev, addrp, |
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i2cdev_check_mux_children); |
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else |
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result = i2cdev_check(dev, addrp); |
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return result; |
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} |
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/* This address checking function differs from the one in i2c-core |
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in that it considers an address with a registered device, but no |
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driver bound to it, as NOT busy. */ |
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static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
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{ |
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struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
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int result = 0; |
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if (parent) |
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result = i2cdev_check_mux_parents(parent, addr); |
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if (!result) |
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result = device_for_each_child(&adapter->dev, &addr, |
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i2cdev_check_mux_children); |
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return result; |
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} |
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static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
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unsigned nmsgs, struct i2c_msg *msgs) |
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{ |
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u8 __user **data_ptrs; |
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int i, res; |
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data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL); |
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if (data_ptrs == NULL) { |
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kfree(msgs); |
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return -ENOMEM; |
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} |
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res = 0; |
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for (i = 0; i < nmsgs; i++) { |
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/* Limit the size of the message to a sane amount */ |
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if (msgs[i].len > 8192) { |
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res = -EINVAL; |
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break; |
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} |
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data_ptrs[i] = (u8 __user *)msgs[i].buf; |
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msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len); |
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if (IS_ERR(msgs[i].buf)) { |
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res = PTR_ERR(msgs[i].buf); |
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break; |
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} |
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/* memdup_user allocates with GFP_KERNEL, so DMA is ok */ |
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msgs[i].flags |= I2C_M_DMA_SAFE; |
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/* |
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* If the message length is received from the slave (similar |
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* to SMBus block read), we must ensure that the buffer will |
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* be large enough to cope with a message length of |
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* I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus |
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* drivers allow. The first byte in the buffer must be |
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* pre-filled with the number of extra bytes, which must be |
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* at least one to hold the message length, but can be |
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* greater (for example to account for a checksum byte at |
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* the end of the message.) |
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*/ |
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if (msgs[i].flags & I2C_M_RECV_LEN) { |
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if (!(msgs[i].flags & I2C_M_RD) || |
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msgs[i].len < 1 || msgs[i].buf[0] < 1 || |
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msgs[i].len < msgs[i].buf[0] + |
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I2C_SMBUS_BLOCK_MAX) { |
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i++; |
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res = -EINVAL; |
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break; |
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} |
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msgs[i].len = msgs[i].buf[0]; |
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} |
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} |
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if (res < 0) { |
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int j; |
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for (j = 0; j < i; ++j) |
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kfree(msgs[j].buf); |
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kfree(data_ptrs); |
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kfree(msgs); |
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return res; |
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} |
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res = i2c_transfer(client->adapter, msgs, nmsgs); |
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while (i-- > 0) { |
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if (res >= 0 && (msgs[i].flags & I2C_M_RD)) { |
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if (copy_to_user(data_ptrs[i], msgs[i].buf, |
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msgs[i].len)) |
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res = -EFAULT; |
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} |
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kfree(msgs[i].buf); |
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} |
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kfree(data_ptrs); |
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kfree(msgs); |
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return res; |
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} |
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static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, |
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u8 read_write, u8 command, u32 size, |
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union i2c_smbus_data __user *data) |
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{ |
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union i2c_smbus_data temp = {}; |
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int datasize, res; |
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if ((size != I2C_SMBUS_BYTE) && |
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(size != I2C_SMBUS_QUICK) && |
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(size != I2C_SMBUS_BYTE_DATA) && |
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(size != I2C_SMBUS_WORD_DATA) && |
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(size != I2C_SMBUS_PROC_CALL) && |
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(size != I2C_SMBUS_BLOCK_DATA) && |
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(size != I2C_SMBUS_I2C_BLOCK_BROKEN) && |
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(size != I2C_SMBUS_I2C_BLOCK_DATA) && |
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(size != I2C_SMBUS_BLOCK_PROC_CALL)) { |
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dev_dbg(&client->adapter->dev, |
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"size out of range (%x) in ioctl I2C_SMBUS.\n", |
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size); |
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return -EINVAL; |
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} |
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/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, |
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so the check is valid if size==I2C_SMBUS_QUICK too. */ |
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if ((read_write != I2C_SMBUS_READ) && |
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(read_write != I2C_SMBUS_WRITE)) { |
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dev_dbg(&client->adapter->dev, |
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"read_write out of range (%x) in ioctl I2C_SMBUS.\n", |
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read_write); |
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return -EINVAL; |
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} |
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/* Note that command values are always valid! */ |
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if ((size == I2C_SMBUS_QUICK) || |
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((size == I2C_SMBUS_BYTE) && |
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(read_write == I2C_SMBUS_WRITE))) |
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/* These are special: we do not use data */ |
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return i2c_smbus_xfer(client->adapter, client->addr, |
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client->flags, read_write, |
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command, size, NULL); |
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if (data == NULL) { |
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dev_dbg(&client->adapter->dev, |
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"data is NULL pointer in ioctl I2C_SMBUS.\n"); |
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return -EINVAL; |
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} |
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if ((size == I2C_SMBUS_BYTE_DATA) || |
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(size == I2C_SMBUS_BYTE)) |
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datasize = sizeof(data->byte); |
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else if ((size == I2C_SMBUS_WORD_DATA) || |
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(size == I2C_SMBUS_PROC_CALL)) |
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datasize = sizeof(data->word); |
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else /* size == smbus block, i2c block, or block proc. call */ |
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datasize = sizeof(data->block); |
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if ((size == I2C_SMBUS_PROC_CALL) || |
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(size == I2C_SMBUS_BLOCK_PROC_CALL) || |
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(size == I2C_SMBUS_I2C_BLOCK_DATA) || |
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(read_write == I2C_SMBUS_WRITE)) { |
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if (copy_from_user(&temp, data, datasize)) |
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return -EFAULT; |
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} |
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if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) { |
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/* Convert old I2C block commands to the new |
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convention. This preserves binary compatibility. */ |
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size = I2C_SMBUS_I2C_BLOCK_DATA; |
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if (read_write == I2C_SMBUS_READ) |
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temp.block[0] = I2C_SMBUS_BLOCK_MAX; |
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} |
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res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
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read_write, command, size, &temp); |
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if (!res && ((size == I2C_SMBUS_PROC_CALL) || |
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(size == I2C_SMBUS_BLOCK_PROC_CALL) || |
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(read_write == I2C_SMBUS_READ))) { |
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if (copy_to_user(data, &temp, datasize)) |
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return -EFAULT; |
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} |
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return res; |
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} |
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static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
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{ |
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struct i2c_client *client = file->private_data; |
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unsigned long funcs; |
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dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
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cmd, arg); |
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switch (cmd) { |
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case I2C_SLAVE: |
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case I2C_SLAVE_FORCE: |
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if ((arg > 0x3ff) || |
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(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
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return -EINVAL; |
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if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
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return -EBUSY; |
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/* REVISIT: address could become busy later */ |
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client->addr = arg; |
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return 0; |
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case I2C_TENBIT: |
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if (arg) |
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client->flags |= I2C_M_TEN; |
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else |
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client->flags &= ~I2C_M_TEN; |
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return 0; |
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case I2C_PEC: |
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/* |
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* Setting the PEC flag here won't affect kernel drivers, |
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* which will be using the i2c_client node registered with |
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* the driver model core. Likewise, when that client has |
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* the PEC flag already set, the i2c-dev driver won't see |
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* (or use) this setting. |
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*/ |
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if (arg) |
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client->flags |= I2C_CLIENT_PEC; |
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else |
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client->flags &= ~I2C_CLIENT_PEC; |
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return 0; |
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case I2C_FUNCS: |
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funcs = i2c_get_functionality(client->adapter); |
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return put_user(funcs, (unsigned long __user *)arg); |
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|
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case I2C_RDWR: { |
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struct i2c_rdwr_ioctl_data rdwr_arg; |
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struct i2c_msg *rdwr_pa; |
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if (copy_from_user(&rdwr_arg, |
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(struct i2c_rdwr_ioctl_data __user *)arg, |
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sizeof(rdwr_arg))) |
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return -EFAULT; |
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|
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if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0) |
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return -EINVAL; |
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/* |
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* Put an arbitrary limit on the number of messages that can |
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* be sent at once |
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*/ |
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if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) |
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return -EINVAL; |
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rdwr_pa = memdup_user(rdwr_arg.msgs, |
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rdwr_arg.nmsgs * sizeof(struct i2c_msg)); |
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if (IS_ERR(rdwr_pa)) |
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return PTR_ERR(rdwr_pa); |
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return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); |
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} |
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case I2C_SMBUS: { |
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struct i2c_smbus_ioctl_data data_arg; |
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if (copy_from_user(&data_arg, |
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(struct i2c_smbus_ioctl_data __user *) arg, |
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sizeof(struct i2c_smbus_ioctl_data))) |
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return -EFAULT; |
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return i2cdev_ioctl_smbus(client, data_arg.read_write, |
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data_arg.command, |
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data_arg.size, |
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data_arg.data); |
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} |
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case I2C_RETRIES: |
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if (arg > INT_MAX) |
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return -EINVAL; |
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|
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client->adapter->retries = arg; |
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break; |
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case I2C_TIMEOUT: |
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if (arg > INT_MAX) |
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return -EINVAL; |
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|
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/* For historical reasons, user-space sets the timeout |
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* value in units of 10 ms. |
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*/ |
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client->adapter->timeout = msecs_to_jiffies(arg * 10); |
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break; |
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default: |
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/* NOTE: returning a fault code here could cause trouble |
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* in buggy userspace code. Some old kernel bugs returned |
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* zero in this case, and userspace code might accidentally |
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* have depended on that bug. |
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*/ |
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return -ENOTTY; |
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} |
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return 0; |
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} |
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|
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#ifdef CONFIG_COMPAT |
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|
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struct i2c_smbus_ioctl_data32 { |
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u8 read_write; |
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u8 command; |
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u32 size; |
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compat_caddr_t data; /* union i2c_smbus_data *data */ |
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}; |
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struct i2c_msg32 { |
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u16 addr; |
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u16 flags; |
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u16 len; |
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compat_caddr_t buf; |
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}; |
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|
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struct i2c_rdwr_ioctl_data32 { |
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compat_caddr_t msgs; /* struct i2c_msg __user *msgs */ |
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u32 nmsgs; |
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}; |
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|
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static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
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{ |
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struct i2c_client *client = file->private_data; |
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unsigned long funcs; |
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switch (cmd) { |
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case I2C_FUNCS: |
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funcs = i2c_get_functionality(client->adapter); |
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return put_user(funcs, (compat_ulong_t __user *)arg); |
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case I2C_RDWR: { |
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struct i2c_rdwr_ioctl_data32 rdwr_arg; |
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struct i2c_msg32 __user *p; |
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struct i2c_msg *rdwr_pa; |
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int i; |
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|
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if (copy_from_user(&rdwr_arg, |
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(struct i2c_rdwr_ioctl_data32 __user *)arg, |
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sizeof(rdwr_arg))) |
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return -EFAULT; |
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|
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if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) |
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return -EINVAL; |
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|
|
rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg), |
|
GFP_KERNEL); |
|
if (!rdwr_pa) |
|
return -ENOMEM; |
|
|
|
p = compat_ptr(rdwr_arg.msgs); |
|
for (i = 0; i < rdwr_arg.nmsgs; i++) { |
|
struct i2c_msg32 umsg; |
|
if (copy_from_user(&umsg, p + i, sizeof(umsg))) { |
|
kfree(rdwr_pa); |
|
return -EFAULT; |
|
} |
|
rdwr_pa[i] = (struct i2c_msg) { |
|
.addr = umsg.addr, |
|
.flags = umsg.flags, |
|
.len = umsg.len, |
|
.buf = compat_ptr(umsg.buf) |
|
}; |
|
} |
|
|
|
return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); |
|
} |
|
case I2C_SMBUS: { |
|
struct i2c_smbus_ioctl_data32 data32; |
|
if (copy_from_user(&data32, |
|
(void __user *) arg, |
|
sizeof(data32))) |
|
return -EFAULT; |
|
return i2cdev_ioctl_smbus(client, data32.read_write, |
|
data32.command, |
|
data32.size, |
|
compat_ptr(data32.data)); |
|
} |
|
default: |
|
return i2cdev_ioctl(file, cmd, arg); |
|
} |
|
} |
|
#else |
|
#define compat_i2cdev_ioctl NULL |
|
#endif |
|
|
|
static int i2cdev_open(struct inode *inode, struct file *file) |
|
{ |
|
unsigned int minor = iminor(inode); |
|
struct i2c_client *client; |
|
struct i2c_adapter *adap; |
|
|
|
adap = i2c_get_adapter(minor); |
|
if (!adap) |
|
return -ENODEV; |
|
|
|
/* This creates an anonymous i2c_client, which may later be |
|
* pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. |
|
* |
|
* This client is ** NEVER REGISTERED ** with the driver model |
|
* or I2C core code!! It just holds private copies of addressing |
|
* information and maybe a PEC flag. |
|
*/ |
|
client = kzalloc(sizeof(*client), GFP_KERNEL); |
|
if (!client) { |
|
i2c_put_adapter(adap); |
|
return -ENOMEM; |
|
} |
|
snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
|
|
|
client->adapter = adap; |
|
file->private_data = client; |
|
|
|
return 0; |
|
} |
|
|
|
static int i2cdev_release(struct inode *inode, struct file *file) |
|
{ |
|
struct i2c_client *client = file->private_data; |
|
|
|
i2c_put_adapter(client->adapter); |
|
kfree(client); |
|
file->private_data = NULL; |
|
|
|
return 0; |
|
} |
|
|
|
static const struct file_operations i2cdev_fops = { |
|
.owner = THIS_MODULE, |
|
.llseek = no_llseek, |
|
.read = i2cdev_read, |
|
.write = i2cdev_write, |
|
.unlocked_ioctl = i2cdev_ioctl, |
|
.compat_ioctl = compat_i2cdev_ioctl, |
|
.open = i2cdev_open, |
|
.release = i2cdev_release, |
|
}; |
|
|
|
/* ------------------------------------------------------------------------- */ |
|
|
|
static struct class *i2c_dev_class; |
|
|
|
static void i2cdev_dev_release(struct device *dev) |
|
{ |
|
struct i2c_dev *i2c_dev; |
|
|
|
i2c_dev = container_of(dev, struct i2c_dev, dev); |
|
kfree(i2c_dev); |
|
} |
|
|
|
static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
|
{ |
|
struct i2c_adapter *adap; |
|
struct i2c_dev *i2c_dev; |
|
int res; |
|
|
|
if (dev->type != &i2c_adapter_type) |
|
return 0; |
|
adap = to_i2c_adapter(dev); |
|
|
|
i2c_dev = get_free_i2c_dev(adap); |
|
if (IS_ERR(i2c_dev)) |
|
return PTR_ERR(i2c_dev); |
|
|
|
cdev_init(&i2c_dev->cdev, &i2cdev_fops); |
|
i2c_dev->cdev.owner = THIS_MODULE; |
|
|
|
device_initialize(&i2c_dev->dev); |
|
i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr); |
|
i2c_dev->dev.class = i2c_dev_class; |
|
i2c_dev->dev.parent = &adap->dev; |
|
i2c_dev->dev.release = i2cdev_dev_release; |
|
dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr); |
|
|
|
res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev); |
|
if (res) { |
|
put_i2c_dev(i2c_dev, false); |
|
return res; |
|
} |
|
|
|
pr_debug("adapter [%s] registered as minor %d\n", adap->name, adap->nr); |
|
return 0; |
|
} |
|
|
|
static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
|
{ |
|
struct i2c_adapter *adap; |
|
struct i2c_dev *i2c_dev; |
|
|
|
if (dev->type != &i2c_adapter_type) |
|
return 0; |
|
adap = to_i2c_adapter(dev); |
|
|
|
i2c_dev = i2c_dev_get_by_minor(adap->nr); |
|
if (!i2c_dev) /* attach_adapter must have failed */ |
|
return 0; |
|
|
|
put_i2c_dev(i2c_dev, true); |
|
|
|
pr_debug("adapter [%s] unregistered\n", adap->name); |
|
return 0; |
|
} |
|
|
|
static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
|
void *data) |
|
{ |
|
struct device *dev = data; |
|
|
|
switch (action) { |
|
case BUS_NOTIFY_ADD_DEVICE: |
|
return i2cdev_attach_adapter(dev, NULL); |
|
case BUS_NOTIFY_DEL_DEVICE: |
|
return i2cdev_detach_adapter(dev, NULL); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static struct notifier_block i2cdev_notifier = { |
|
.notifier_call = i2cdev_notifier_call, |
|
}; |
|
|
|
/* ------------------------------------------------------------------------- */ |
|
|
|
/* |
|
* module load/unload record keeping |
|
*/ |
|
|
|
static int __init i2c_dev_init(void) |
|
{ |
|
int res; |
|
|
|
pr_info("i2c /dev entries driver\n"); |
|
|
|
res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); |
|
if (res) |
|
goto out; |
|
|
|
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
|
if (IS_ERR(i2c_dev_class)) { |
|
res = PTR_ERR(i2c_dev_class); |
|
goto out_unreg_chrdev; |
|
} |
|
i2c_dev_class->dev_groups = i2c_groups; |
|
|
|
/* Keep track of adapters which will be added or removed later */ |
|
res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); |
|
if (res) |
|
goto out_unreg_class; |
|
|
|
/* Bind to already existing adapters right away */ |
|
i2c_for_each_dev(NULL, i2cdev_attach_adapter); |
|
|
|
return 0; |
|
|
|
out_unreg_class: |
|
class_destroy(i2c_dev_class); |
|
out_unreg_chrdev: |
|
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
|
out: |
|
pr_err("Driver Initialisation failed\n"); |
|
return res; |
|
} |
|
|
|
static void __exit i2c_dev_exit(void) |
|
{ |
|
bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
|
i2c_for_each_dev(NULL, i2cdev_detach_adapter); |
|
class_destroy(i2c_dev_class); |
|
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
|
} |
|
|
|
MODULE_AUTHOR("Frodo Looijaard <[email protected]>"); |
|
MODULE_AUTHOR("Simon G. Vogl <[email protected]>"); |
|
MODULE_DESCRIPTION("I2C /dev entries driver"); |
|
MODULE_LICENSE("GPL"); |
|
|
|
module_init(i2c_dev_init); |
|
module_exit(i2c_dev_exit);
|
|
|