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1054 lines
27 KiB
1054 lines
27 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* OF helpers for the GPIO API |
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* |
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* Copyright (c) 2007-2008 MontaVista Software, Inc. |
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* |
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* Author: Anton Vorontsov <[email protected]> |
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*/ |
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|
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/errno.h> |
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#include <linux/module.h> |
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#include <linux/io.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/of.h> |
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#include <linux/of_address.h> |
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#include <linux/of_gpio.h> |
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#include <linux/pinctrl/pinctrl.h> |
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#include <linux/slab.h> |
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#include <linux/gpio/machine.h> |
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|
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#include "gpiolib.h" |
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#include "gpiolib-of.h" |
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|
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/** |
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* of_gpio_spi_cs_get_count() - special GPIO counting for SPI |
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* @dev: Consuming device |
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* @con_id: Function within the GPIO consumer |
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* |
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* Some elder GPIO controllers need special quirks. Currently we handle |
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* the Freescale and PPC GPIO controller with bindings that doesn't use the |
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* established "cs-gpios" for chip selects but instead rely on |
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* "gpios" for the chip select lines. If we detect this, we redirect |
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* the counting of "cs-gpios" to count "gpios" transparent to the |
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* driver. |
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*/ |
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static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id) |
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{ |
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struct device_node *np = dev->of_node; |
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|
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if (!IS_ENABLED(CONFIG_SPI_MASTER)) |
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return 0; |
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if (!con_id || strcmp(con_id, "cs")) |
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return 0; |
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if (!of_device_is_compatible(np, "fsl,spi") && |
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!of_device_is_compatible(np, "aeroflexgaisler,spictrl") && |
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!of_device_is_compatible(np, "ibm,ppc4xx-spi")) |
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return 0; |
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return of_gpio_named_count(np, "gpios"); |
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} |
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|
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/* |
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* This is used by external users of of_gpio_count() from <linux/of_gpio.h> |
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* |
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* FIXME: get rid of those external users by converting them to GPIO |
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* descriptors and let them all use gpiod_count() |
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*/ |
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int of_gpio_get_count(struct device *dev, const char *con_id) |
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{ |
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int ret; |
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char propname[32]; |
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unsigned int i; |
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|
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ret = of_gpio_spi_cs_get_count(dev, con_id); |
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if (ret > 0) |
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return ret; |
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|
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for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { |
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if (con_id) |
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snprintf(propname, sizeof(propname), "%s-%s", |
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con_id, gpio_suffixes[i]); |
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else |
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snprintf(propname, sizeof(propname), "%s", |
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gpio_suffixes[i]); |
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|
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ret = of_gpio_named_count(dev->of_node, propname); |
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if (ret > 0) |
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break; |
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} |
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return ret ? ret : -ENOENT; |
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} |
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|
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static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data) |
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{ |
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struct of_phandle_args *gpiospec = data; |
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|
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return chip->gpiodev->dev.of_node == gpiospec->np && |
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chip->of_xlate && |
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chip->of_xlate(chip, gpiospec, NULL) >= 0; |
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} |
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|
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static struct gpio_chip *of_find_gpiochip_by_xlate( |
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struct of_phandle_args *gpiospec) |
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{ |
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return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate); |
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} |
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|
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static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, |
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struct of_phandle_args *gpiospec, |
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enum of_gpio_flags *flags) |
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{ |
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int ret; |
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|
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if (chip->of_gpio_n_cells != gpiospec->args_count) |
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return ERR_PTR(-EINVAL); |
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|
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ret = chip->of_xlate(chip, gpiospec, flags); |
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if (ret < 0) |
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return ERR_PTR(ret); |
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|
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return gpiochip_get_desc(chip, ret); |
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} |
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|
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/** |
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* of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs |
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* to set the .valid_mask |
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* @gc: the target gpio_chip |
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* |
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* Return: true if the valid mask needs to be set |
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*/ |
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bool of_gpio_need_valid_mask(const struct gpio_chip *gc) |
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{ |
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int size; |
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const struct device_node *np = gc->of_node; |
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|
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size = of_property_count_u32_elems(np, "gpio-reserved-ranges"); |
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if (size > 0 && size % 2 == 0) |
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return true; |
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return false; |
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} |
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|
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static void of_gpio_flags_quirks(const struct device_node *np, |
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const char *propname, |
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enum of_gpio_flags *flags, |
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int index) |
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{ |
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/* |
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* Some GPIO fixed regulator quirks. |
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* Note that active low is the default. |
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*/ |
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if (IS_ENABLED(CONFIG_REGULATOR) && |
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(of_device_is_compatible(np, "regulator-fixed") || |
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of_device_is_compatible(np, "reg-fixed-voltage") || |
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(!(strcmp(propname, "enable-gpio") && |
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strcmp(propname, "enable-gpios")) && |
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of_device_is_compatible(np, "regulator-gpio")))) { |
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bool active_low = !of_property_read_bool(np, |
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"enable-active-high"); |
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/* |
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* The regulator GPIO handles are specified such that the |
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* presence or absence of "enable-active-high" solely controls |
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* the polarity of the GPIO line. Any phandle flags must |
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* be actively ignored. |
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*/ |
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if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) { |
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pr_warn("%s GPIO handle specifies active low - ignored\n", |
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of_node_full_name(np)); |
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*flags &= ~OF_GPIO_ACTIVE_LOW; |
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} |
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if (active_low) |
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*flags |= OF_GPIO_ACTIVE_LOW; |
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} |
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/* |
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* Legacy open drain handling for fixed voltage regulators. |
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*/ |
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if (IS_ENABLED(CONFIG_REGULATOR) && |
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of_device_is_compatible(np, "reg-fixed-voltage") && |
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of_property_read_bool(np, "gpio-open-drain")) { |
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*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN); |
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pr_info("%s uses legacy open drain flag - update the DTS if you can\n", |
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of_node_full_name(np)); |
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} |
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|
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/* |
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* Legacy handling of SPI active high chip select. If we have a |
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* property named "cs-gpios" we need to inspect the child node |
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* to determine if the flags should have inverted semantics. |
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*/ |
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if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") && |
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of_property_read_bool(np, "cs-gpios")) { |
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struct device_node *child; |
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u32 cs; |
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int ret; |
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|
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for_each_child_of_node(np, child) { |
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ret = of_property_read_u32(child, "reg", &cs); |
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if (ret) |
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continue; |
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if (cs == index) { |
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/* |
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* SPI children have active low chip selects |
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* by default. This can be specified negatively |
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* by just omitting "spi-cs-high" in the |
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* device node, or actively by tagging on |
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* GPIO_ACTIVE_LOW as flag in the device |
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* tree. If the line is simultaneously |
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* tagged as active low in the device tree |
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* and has the "spi-cs-high" set, we get a |
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* conflict and the "spi-cs-high" flag will |
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* take precedence. |
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*/ |
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if (of_property_read_bool(child, "spi-cs-high")) { |
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if (*flags & OF_GPIO_ACTIVE_LOW) { |
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pr_warn("%s GPIO handle specifies active low - ignored\n", |
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of_node_full_name(child)); |
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*flags &= ~OF_GPIO_ACTIVE_LOW; |
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} |
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} else { |
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if (!(*flags & OF_GPIO_ACTIVE_LOW)) |
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pr_info("%s enforce active low on chipselect handle\n", |
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of_node_full_name(child)); |
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*flags |= OF_GPIO_ACTIVE_LOW; |
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} |
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of_node_put(child); |
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break; |
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} |
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} |
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} |
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|
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/* Legacy handling of stmmac's active-low PHY reset line */ |
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if (IS_ENABLED(CONFIG_STMMAC_ETH) && |
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!strcmp(propname, "snps,reset-gpio") && |
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of_property_read_bool(np, "snps,reset-active-low")) |
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*flags |= OF_GPIO_ACTIVE_LOW; |
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} |
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|
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/** |
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* of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API |
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* @np: device node to get GPIO from |
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* @propname: property name containing gpio specifier(s) |
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* @index: index of the GPIO |
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* @flags: a flags pointer to fill in |
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* |
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* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno |
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* value on the error condition. If @flags is not NULL the function also fills |
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* in flags for the GPIO. |
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*/ |
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static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np, |
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const char *propname, int index, enum of_gpio_flags *flags) |
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{ |
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struct of_phandle_args gpiospec; |
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struct gpio_chip *chip; |
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struct gpio_desc *desc; |
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int ret; |
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ret = of_parse_phandle_with_args_map(np, propname, "gpio", index, |
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&gpiospec); |
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if (ret) { |
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pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n", |
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__func__, propname, np, index); |
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return ERR_PTR(ret); |
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} |
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chip = of_find_gpiochip_by_xlate(&gpiospec); |
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if (!chip) { |
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desc = ERR_PTR(-EPROBE_DEFER); |
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goto out; |
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} |
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desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); |
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if (IS_ERR(desc)) |
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goto out; |
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if (flags) |
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of_gpio_flags_quirks(np, propname, flags, index); |
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|
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pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", |
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__func__, propname, np, index, |
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PTR_ERR_OR_ZERO(desc)); |
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|
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out: |
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of_node_put(gpiospec.np); |
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|
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return desc; |
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} |
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|
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int of_get_named_gpio_flags(const struct device_node *np, const char *list_name, |
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int index, enum of_gpio_flags *flags) |
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{ |
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struct gpio_desc *desc; |
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desc = of_get_named_gpiod_flags(np, list_name, index, flags); |
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if (IS_ERR(desc)) |
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return PTR_ERR(desc); |
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else |
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return desc_to_gpio(desc); |
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} |
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EXPORT_SYMBOL_GPL(of_get_named_gpio_flags); |
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|
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/** |
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* gpiod_get_from_of_node() - obtain a GPIO from an OF node |
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* @node: handle of the OF node |
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* @propname: name of the DT property representing the GPIO |
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* @index: index of the GPIO to obtain for the consumer |
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* @dflags: GPIO initialization flags |
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* @label: label to attach to the requested GPIO |
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* |
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* Returns: |
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* On successful request the GPIO pin is configured in accordance with |
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* provided @dflags. |
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* |
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* In case of error an ERR_PTR() is returned. |
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*/ |
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struct gpio_desc *gpiod_get_from_of_node(const struct device_node *node, |
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const char *propname, int index, |
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enum gpiod_flags dflags, |
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const char *label) |
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{ |
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unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT; |
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struct gpio_desc *desc; |
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enum of_gpio_flags flags; |
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bool active_low = false; |
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bool single_ended = false; |
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bool open_drain = false; |
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bool transitory = false; |
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int ret; |
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desc = of_get_named_gpiod_flags(node, propname, |
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index, &flags); |
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|
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if (!desc || IS_ERR(desc)) { |
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return desc; |
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} |
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active_low = flags & OF_GPIO_ACTIVE_LOW; |
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single_ended = flags & OF_GPIO_SINGLE_ENDED; |
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open_drain = flags & OF_GPIO_OPEN_DRAIN; |
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transitory = flags & OF_GPIO_TRANSITORY; |
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|
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ret = gpiod_request(desc, label); |
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if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) |
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return desc; |
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if (ret) |
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return ERR_PTR(ret); |
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|
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if (active_low) |
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lflags |= GPIO_ACTIVE_LOW; |
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|
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if (single_ended) { |
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if (open_drain) |
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lflags |= GPIO_OPEN_DRAIN; |
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else |
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lflags |= GPIO_OPEN_SOURCE; |
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} |
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|
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if (transitory) |
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lflags |= GPIO_TRANSITORY; |
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|
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if (flags & OF_GPIO_PULL_UP) |
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lflags |= GPIO_PULL_UP; |
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|
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if (flags & OF_GPIO_PULL_DOWN) |
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lflags |= GPIO_PULL_DOWN; |
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|
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ret = gpiod_configure_flags(desc, propname, lflags, dflags); |
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if (ret < 0) { |
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gpiod_put(desc); |
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return ERR_PTR(ret); |
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} |
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|
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return desc; |
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} |
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EXPORT_SYMBOL_GPL(gpiod_get_from_of_node); |
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|
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/* |
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* The SPI GPIO bindings happened before we managed to establish that GPIO |
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* properties should be named "foo-gpios" so we have this special kludge for |
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* them. |
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*/ |
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static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id, |
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enum of_gpio_flags *of_flags) |
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{ |
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char prop_name[32]; /* 32 is max size of property name */ |
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const struct device_node *np = dev->of_node; |
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struct gpio_desc *desc; |
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|
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/* |
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* Hopefully the compiler stubs the rest of the function if this |
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* is false. |
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*/ |
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if (!IS_ENABLED(CONFIG_SPI_MASTER)) |
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return ERR_PTR(-ENOENT); |
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|
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/* Allow this specifically for "spi-gpio" devices */ |
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if (!of_device_is_compatible(np, "spi-gpio") || !con_id) |
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return ERR_PTR(-ENOENT); |
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|
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/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */ |
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snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id); |
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|
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desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags); |
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return desc; |
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} |
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|
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/* |
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* The old Freescale bindings use simply "gpios" as name for the chip select |
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* lines rather than "cs-gpios" like all other SPI hardware. Account for this |
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* with a special quirk. |
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*/ |
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static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev, |
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const char *con_id, |
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unsigned int idx, |
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unsigned long *flags) |
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{ |
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const struct device_node *np = dev->of_node; |
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|
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if (!IS_ENABLED(CONFIG_SPI_MASTER)) |
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return ERR_PTR(-ENOENT); |
|
|
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/* Allow this specifically for Freescale and PPC devices */ |
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if (!of_device_is_compatible(np, "fsl,spi") && |
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!of_device_is_compatible(np, "aeroflexgaisler,spictrl") && |
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!of_device_is_compatible(np, "ibm,ppc4xx-spi")) |
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return ERR_PTR(-ENOENT); |
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/* Allow only if asking for "cs-gpios" */ |
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if (!con_id || strcmp(con_id, "cs")) |
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return ERR_PTR(-ENOENT); |
|
|
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/* |
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* While all other SPI controllers use "cs-gpios" the Freescale |
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* uses just "gpios" so translate to that when "cs-gpios" is |
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* requested. |
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*/ |
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return of_find_gpio(dev, NULL, idx, flags); |
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} |
|
|
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/* |
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* Some regulator bindings happened before we managed to establish that GPIO |
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* properties should be named "foo-gpios" so we have this special kludge for |
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* them. |
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*/ |
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static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id, |
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enum of_gpio_flags *of_flags) |
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{ |
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/* These are the connection IDs we accept as legacy GPIO phandles */ |
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const char *whitelist[] = { |
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"wlf,ldoena", /* Arizona */ |
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"wlf,ldo1ena", /* WM8994 */ |
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"wlf,ldo2ena", /* WM8994 */ |
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}; |
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const struct device_node *np = dev->of_node; |
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struct gpio_desc *desc; |
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int i; |
|
|
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if (!IS_ENABLED(CONFIG_REGULATOR)) |
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return ERR_PTR(-ENOENT); |
|
|
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if (!con_id) |
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return ERR_PTR(-ENOENT); |
|
|
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i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id); |
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if (i < 0) |
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return ERR_PTR(-ENOENT); |
|
|
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desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags); |
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return desc; |
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} |
|
|
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static struct gpio_desc *of_find_arizona_gpio(struct device *dev, |
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const char *con_id, |
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enum of_gpio_flags *of_flags) |
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{ |
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if (!IS_ENABLED(CONFIG_MFD_ARIZONA)) |
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return ERR_PTR(-ENOENT); |
|
|
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if (!con_id || strcmp(con_id, "wlf,reset")) |
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return ERR_PTR(-ENOENT); |
|
|
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return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags); |
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} |
|
|
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static struct gpio_desc *of_find_usb_gpio(struct device *dev, |
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const char *con_id, |
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enum of_gpio_flags *of_flags) |
|
{ |
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/* |
|
* Currently this USB quirk is only for the Fairchild FUSB302 host which is using |
|
* an undocumented DT GPIO line named "fcs,int_n" without the compulsory "-gpios" |
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* suffix. |
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*/ |
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if (!IS_ENABLED(CONFIG_TYPEC_FUSB302)) |
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return ERR_PTR(-ENOENT); |
|
|
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if (!con_id || strcmp(con_id, "fcs,int_n")) |
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return ERR_PTR(-ENOENT); |
|
|
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return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags); |
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} |
|
|
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struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, |
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unsigned int idx, unsigned long *flags) |
|
{ |
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char prop_name[32]; /* 32 is max size of property name */ |
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enum of_gpio_flags of_flags; |
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struct gpio_desc *desc; |
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unsigned int i; |
|
|
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/* Try GPIO property "foo-gpios" and "foo-gpio" */ |
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for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { |
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if (con_id) |
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snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, |
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gpio_suffixes[i]); |
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else |
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snprintf(prop_name, sizeof(prop_name), "%s", |
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gpio_suffixes[i]); |
|
|
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desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, |
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&of_flags); |
|
|
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if (!gpiod_not_found(desc)) |
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break; |
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} |
|
|
|
if (gpiod_not_found(desc)) { |
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/* Special handling for SPI GPIOs if used */ |
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desc = of_find_spi_gpio(dev, con_id, &of_flags); |
|
} |
|
|
|
if (gpiod_not_found(desc)) { |
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/* This quirk looks up flags and all */ |
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desc = of_find_spi_cs_gpio(dev, con_id, idx, flags); |
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if (!IS_ERR(desc)) |
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return desc; |
|
} |
|
|
|
if (gpiod_not_found(desc)) { |
|
/* Special handling for regulator GPIOs if used */ |
|
desc = of_find_regulator_gpio(dev, con_id, &of_flags); |
|
} |
|
|
|
if (gpiod_not_found(desc)) |
|
desc = of_find_arizona_gpio(dev, con_id, &of_flags); |
|
|
|
if (gpiod_not_found(desc)) |
|
desc = of_find_usb_gpio(dev, con_id, &of_flags); |
|
|
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if (IS_ERR(desc)) |
|
return desc; |
|
|
|
if (of_flags & OF_GPIO_ACTIVE_LOW) |
|
*flags |= GPIO_ACTIVE_LOW; |
|
|
|
if (of_flags & OF_GPIO_SINGLE_ENDED) { |
|
if (of_flags & OF_GPIO_OPEN_DRAIN) |
|
*flags |= GPIO_OPEN_DRAIN; |
|
else |
|
*flags |= GPIO_OPEN_SOURCE; |
|
} |
|
|
|
if (of_flags & OF_GPIO_TRANSITORY) |
|
*flags |= GPIO_TRANSITORY; |
|
|
|
if (of_flags & OF_GPIO_PULL_UP) |
|
*flags |= GPIO_PULL_UP; |
|
if (of_flags & OF_GPIO_PULL_DOWN) |
|
*flags |= GPIO_PULL_DOWN; |
|
|
|
return desc; |
|
} |
|
|
|
/** |
|
* of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API |
|
* @np: device node to get GPIO from |
|
* @chip: GPIO chip whose hog is parsed |
|
* @idx: Index of the GPIO to parse |
|
* @name: GPIO line name |
|
* @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from |
|
* of_find_gpio() or of_parse_own_gpio() |
|
* @dflags: gpiod_flags - optional GPIO initialization flags |
|
* |
|
* Returns GPIO descriptor to use with Linux GPIO API, or one of the errno |
|
* value on the error condition. |
|
*/ |
|
static struct gpio_desc *of_parse_own_gpio(struct device_node *np, |
|
struct gpio_chip *chip, |
|
unsigned int idx, const char **name, |
|
unsigned long *lflags, |
|
enum gpiod_flags *dflags) |
|
{ |
|
struct device_node *chip_np; |
|
enum of_gpio_flags xlate_flags; |
|
struct of_phandle_args gpiospec; |
|
struct gpio_desc *desc; |
|
unsigned int i; |
|
u32 tmp; |
|
int ret; |
|
|
|
chip_np = chip->of_node; |
|
if (!chip_np) |
|
return ERR_PTR(-EINVAL); |
|
|
|
xlate_flags = 0; |
|
*lflags = GPIO_LOOKUP_FLAGS_DEFAULT; |
|
*dflags = GPIOD_ASIS; |
|
|
|
ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); |
|
if (ret) |
|
return ERR_PTR(ret); |
|
|
|
gpiospec.np = chip_np; |
|
gpiospec.args_count = tmp; |
|
|
|
for (i = 0; i < tmp; i++) { |
|
ret = of_property_read_u32_index(np, "gpios", idx * tmp + i, |
|
&gpiospec.args[i]); |
|
if (ret) |
|
return ERR_PTR(ret); |
|
} |
|
|
|
desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags); |
|
if (IS_ERR(desc)) |
|
return desc; |
|
|
|
if (xlate_flags & OF_GPIO_ACTIVE_LOW) |
|
*lflags |= GPIO_ACTIVE_LOW; |
|
if (xlate_flags & OF_GPIO_TRANSITORY) |
|
*lflags |= GPIO_TRANSITORY; |
|
if (xlate_flags & OF_GPIO_PULL_UP) |
|
*lflags |= GPIO_PULL_UP; |
|
if (xlate_flags & OF_GPIO_PULL_DOWN) |
|
*lflags |= GPIO_PULL_DOWN; |
|
|
|
if (of_property_read_bool(np, "input")) |
|
*dflags |= GPIOD_IN; |
|
else if (of_property_read_bool(np, "output-low")) |
|
*dflags |= GPIOD_OUT_LOW; |
|
else if (of_property_read_bool(np, "output-high")) |
|
*dflags |= GPIOD_OUT_HIGH; |
|
else { |
|
pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n", |
|
desc_to_gpio(desc), np); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
if (name && of_property_read_string(np, "line-name", name)) |
|
*name = np->name; |
|
|
|
return desc; |
|
} |
|
|
|
/** |
|
* of_gpiochip_add_hog - Add all hogs in a hog device node |
|
* @chip: gpio chip to act on |
|
* @hog: device node describing the hogs |
|
* |
|
* Returns error if it fails otherwise 0 on success. |
|
*/ |
|
static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog) |
|
{ |
|
enum gpiod_flags dflags; |
|
struct gpio_desc *desc; |
|
unsigned long lflags; |
|
const char *name; |
|
unsigned int i; |
|
int ret; |
|
|
|
for (i = 0;; i++) { |
|
desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags); |
|
if (IS_ERR(desc)) |
|
break; |
|
|
|
ret = gpiod_hog(desc, name, lflags, dflags); |
|
if (ret < 0) |
|
return ret; |
|
|
|
#ifdef CONFIG_OF_DYNAMIC |
|
desc->hog = hog; |
|
#endif |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions |
|
* @chip: gpio chip to act on |
|
* |
|
* This is only used by of_gpiochip_add to request/set GPIO initial |
|
* configuration. |
|
* It returns error if it fails otherwise 0 on success. |
|
*/ |
|
static int of_gpiochip_scan_gpios(struct gpio_chip *chip) |
|
{ |
|
struct device_node *np; |
|
int ret; |
|
|
|
for_each_available_child_of_node(chip->of_node, np) { |
|
if (!of_property_read_bool(np, "gpio-hog")) |
|
continue; |
|
|
|
ret = of_gpiochip_add_hog(chip, np); |
|
if (ret < 0) { |
|
of_node_put(np); |
|
return ret; |
|
} |
|
|
|
of_node_set_flag(np, OF_POPULATED); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_OF_DYNAMIC |
|
/** |
|
* of_gpiochip_remove_hog - Remove all hogs in a hog device node |
|
* @chip: gpio chip to act on |
|
* @hog: device node describing the hogs |
|
*/ |
|
static void of_gpiochip_remove_hog(struct gpio_chip *chip, |
|
struct device_node *hog) |
|
{ |
|
struct gpio_desc *descs = chip->gpiodev->descs; |
|
unsigned int i; |
|
|
|
for (i = 0; i < chip->ngpio; i++) { |
|
if (test_bit(FLAG_IS_HOGGED, &descs[i].flags) && |
|
descs[i].hog == hog) |
|
gpiochip_free_own_desc(&descs[i]); |
|
} |
|
} |
|
|
|
static int of_gpiochip_match_node(struct gpio_chip *chip, void *data) |
|
{ |
|
return chip->gpiodev->dev.of_node == data; |
|
} |
|
|
|
static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np) |
|
{ |
|
return gpiochip_find(np, of_gpiochip_match_node); |
|
} |
|
|
|
static int of_gpio_notify(struct notifier_block *nb, unsigned long action, |
|
void *arg) |
|
{ |
|
struct of_reconfig_data *rd = arg; |
|
struct gpio_chip *chip; |
|
int ret; |
|
|
|
/* |
|
* This only supports adding and removing complete gpio-hog nodes. |
|
* Modifying an existing gpio-hog node is not supported (except for |
|
* changing its "status" property, which is treated the same as |
|
* addition/removal). |
|
*/ |
|
switch (of_reconfig_get_state_change(action, arg)) { |
|
case OF_RECONFIG_CHANGE_ADD: |
|
if (!of_property_read_bool(rd->dn, "gpio-hog")) |
|
return NOTIFY_OK; /* not for us */ |
|
|
|
if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) |
|
return NOTIFY_OK; |
|
|
|
chip = of_find_gpiochip_by_node(rd->dn->parent); |
|
if (chip == NULL) |
|
return NOTIFY_OK; /* not for us */ |
|
|
|
ret = of_gpiochip_add_hog(chip, rd->dn); |
|
if (ret < 0) { |
|
pr_err("%s: failed to add hogs for %pOF\n", __func__, |
|
rd->dn); |
|
of_node_clear_flag(rd->dn, OF_POPULATED); |
|
return notifier_from_errno(ret); |
|
} |
|
break; |
|
|
|
case OF_RECONFIG_CHANGE_REMOVE: |
|
if (!of_node_check_flag(rd->dn, OF_POPULATED)) |
|
return NOTIFY_OK; /* already depopulated */ |
|
|
|
chip = of_find_gpiochip_by_node(rd->dn->parent); |
|
if (chip == NULL) |
|
return NOTIFY_OK; /* not for us */ |
|
|
|
of_gpiochip_remove_hog(chip, rd->dn); |
|
of_node_clear_flag(rd->dn, OF_POPULATED); |
|
break; |
|
} |
|
|
|
return NOTIFY_OK; |
|
} |
|
|
|
struct notifier_block gpio_of_notifier = { |
|
.notifier_call = of_gpio_notify, |
|
}; |
|
#endif /* CONFIG_OF_DYNAMIC */ |
|
|
|
/** |
|
* of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags |
|
* @gc: pointer to the gpio_chip structure |
|
* @gpiospec: GPIO specifier as found in the device tree |
|
* @flags: a flags pointer to fill in |
|
* |
|
* This is simple translation function, suitable for the most 1:1 mapped |
|
* GPIO chips. This function performs only one sanity check: whether GPIO |
|
* is less than ngpios (that is specified in the gpio_chip). |
|
*/ |
|
static int of_gpio_simple_xlate(struct gpio_chip *gc, |
|
const struct of_phandle_args *gpiospec, |
|
u32 *flags) |
|
{ |
|
/* |
|
* We're discouraging gpio_cells < 2, since that way you'll have to |
|
* write your own xlate function (that will have to retrieve the GPIO |
|
* number and the flags from a single gpio cell -- this is possible, |
|
* but not recommended). |
|
*/ |
|
if (gc->of_gpio_n_cells < 2) { |
|
WARN_ON(1); |
|
return -EINVAL; |
|
} |
|
|
|
if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) |
|
return -EINVAL; |
|
|
|
if (gpiospec->args[0] >= gc->ngpio) |
|
return -EINVAL; |
|
|
|
if (flags) |
|
*flags = gpiospec->args[1]; |
|
|
|
return gpiospec->args[0]; |
|
} |
|
|
|
/** |
|
* of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) |
|
* @np: device node of the GPIO chip |
|
* @mm_gc: pointer to the of_mm_gpio_chip allocated structure |
|
* @data: driver data to store in the struct gpio_chip |
|
* |
|
* To use this function you should allocate and fill mm_gc with: |
|
* |
|
* 1) In the gpio_chip structure: |
|
* - all the callbacks |
|
* - of_gpio_n_cells |
|
* - of_xlate callback (optional) |
|
* |
|
* 3) In the of_mm_gpio_chip structure: |
|
* - save_regs callback (optional) |
|
* |
|
* If succeeded, this function will map bank's memory and will |
|
* do all necessary work for you. Then you'll able to use .regs |
|
* to manage GPIOs from the callbacks. |
|
*/ |
|
int of_mm_gpiochip_add_data(struct device_node *np, |
|
struct of_mm_gpio_chip *mm_gc, |
|
void *data) |
|
{ |
|
int ret = -ENOMEM; |
|
struct gpio_chip *gc = &mm_gc->gc; |
|
|
|
gc->label = kasprintf(GFP_KERNEL, "%pOF", np); |
|
if (!gc->label) |
|
goto err0; |
|
|
|
mm_gc->regs = of_iomap(np, 0); |
|
if (!mm_gc->regs) |
|
goto err1; |
|
|
|
gc->base = -1; |
|
|
|
if (mm_gc->save_regs) |
|
mm_gc->save_regs(mm_gc); |
|
|
|
mm_gc->gc.of_node = np; |
|
|
|
ret = gpiochip_add_data(gc, data); |
|
if (ret) |
|
goto err2; |
|
|
|
return 0; |
|
err2: |
|
iounmap(mm_gc->regs); |
|
err1: |
|
kfree(gc->label); |
|
err0: |
|
pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data); |
|
|
|
/** |
|
* of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) |
|
* @mm_gc: pointer to the of_mm_gpio_chip allocated structure |
|
*/ |
|
void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) |
|
{ |
|
struct gpio_chip *gc = &mm_gc->gc; |
|
|
|
if (!mm_gc) |
|
return; |
|
|
|
gpiochip_remove(gc); |
|
iounmap(mm_gc->regs); |
|
kfree(gc->label); |
|
} |
|
EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove); |
|
|
|
static void of_gpiochip_init_valid_mask(struct gpio_chip *chip) |
|
{ |
|
int len, i; |
|
u32 start, count; |
|
struct device_node *np = chip->of_node; |
|
|
|
len = of_property_count_u32_elems(np, "gpio-reserved-ranges"); |
|
if (len < 0 || len % 2 != 0) |
|
return; |
|
|
|
for (i = 0; i < len; i += 2) { |
|
of_property_read_u32_index(np, "gpio-reserved-ranges", |
|
i, &start); |
|
of_property_read_u32_index(np, "gpio-reserved-ranges", |
|
i + 1, &count); |
|
if (start >= chip->ngpio || start + count >= chip->ngpio) |
|
continue; |
|
|
|
bitmap_clear(chip->valid_mask, start, count); |
|
} |
|
}; |
|
|
|
#ifdef CONFIG_PINCTRL |
|
static int of_gpiochip_add_pin_range(struct gpio_chip *chip) |
|
{ |
|
struct device_node *np = chip->of_node; |
|
struct of_phandle_args pinspec; |
|
struct pinctrl_dev *pctldev; |
|
int index = 0, ret; |
|
const char *name; |
|
static const char group_names_propname[] = "gpio-ranges-group-names"; |
|
struct property *group_names; |
|
|
|
if (!np) |
|
return 0; |
|
|
|
group_names = of_find_property(np, group_names_propname, NULL); |
|
|
|
for (;; index++) { |
|
ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, |
|
index, &pinspec); |
|
if (ret) |
|
break; |
|
|
|
pctldev = of_pinctrl_get(pinspec.np); |
|
of_node_put(pinspec.np); |
|
if (!pctldev) |
|
return -EPROBE_DEFER; |
|
|
|
if (pinspec.args[2]) { |
|
if (group_names) { |
|
of_property_read_string_index(np, |
|
group_names_propname, |
|
index, &name); |
|
if (strlen(name)) { |
|
pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n", |
|
np); |
|
break; |
|
} |
|
} |
|
/* npins != 0: linear range */ |
|
ret = gpiochip_add_pin_range(chip, |
|
pinctrl_dev_get_devname(pctldev), |
|
pinspec.args[0], |
|
pinspec.args[1], |
|
pinspec.args[2]); |
|
if (ret) |
|
return ret; |
|
} else { |
|
/* npins == 0: special range */ |
|
if (pinspec.args[1]) { |
|
pr_err("%pOF: Illegal gpio-range format.\n", |
|
np); |
|
break; |
|
} |
|
|
|
if (!group_names) { |
|
pr_err("%pOF: GPIO group range requested but no %s property.\n", |
|
np, group_names_propname); |
|
break; |
|
} |
|
|
|
ret = of_property_read_string_index(np, |
|
group_names_propname, |
|
index, &name); |
|
if (ret) |
|
break; |
|
|
|
if (!strlen(name)) { |
|
pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n", |
|
np); |
|
break; |
|
} |
|
|
|
ret = gpiochip_add_pingroup_range(chip, pctldev, |
|
pinspec.args[0], name); |
|
if (ret) |
|
return ret; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
#else |
|
static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } |
|
#endif |
|
|
|
int of_gpiochip_add(struct gpio_chip *chip) |
|
{ |
|
int ret; |
|
|
|
if (!chip->of_node) |
|
return 0; |
|
|
|
if (!chip->of_xlate) { |
|
chip->of_gpio_n_cells = 2; |
|
chip->of_xlate = of_gpio_simple_xlate; |
|
} |
|
|
|
if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) |
|
return -EINVAL; |
|
|
|
of_gpiochip_init_valid_mask(chip); |
|
|
|
ret = of_gpiochip_add_pin_range(chip); |
|
if (ret) |
|
return ret; |
|
|
|
of_node_get(chip->of_node); |
|
|
|
ret = of_gpiochip_scan_gpios(chip); |
|
if (ret) |
|
of_node_put(chip->of_node); |
|
|
|
return ret; |
|
} |
|
|
|
void of_gpiochip_remove(struct gpio_chip *chip) |
|
{ |
|
of_node_put(chip->of_node); |
|
} |
|
|
|
void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev) |
|
{ |
|
/* Set default OF node to parent's one if present */ |
|
if (gc->parent) |
|
gdev->dev.of_node = gc->parent->of_node; |
|
|
|
/* If the gpiochip has an assigned OF node this takes precedence */ |
|
if (gc->of_node) |
|
gdev->dev.of_node = gc->of_node; |
|
else |
|
gc->of_node = gdev->dev.of_node; |
|
}
|
|
|