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![Stefan Wahren](/assets/img/avatar_default.png)
In case leds-gpio fails to get at least one of possibly many GPIOs from the DT (e.g. the GPIO is already requested) neither gpiolib nor the driver does provide any helpful error log: leds-gpio: probe of leds failed with error -16 As the driver knows better how to handle errors with such mandatory GPIOs, let's implement an error log which points to the affected GPIO. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20231202183636.7055-1-wahrenst@gmx.net Signed-off-by: Lee Jones <lee@kernel.org>
331 lines
8.3 KiB
C
331 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* LEDs driver for GPIOs
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*
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* Copyright (C) 2007 8D Technologies inc.
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* Raphael Assenat <raph@8d.com>
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* Copyright (C) 2008 Freescale Semiconductor, Inc.
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*/
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#include <linux/container_of.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/gpio/consumer.h>
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#include <linux/leds.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/overflow.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/property.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include "leds.h"
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struct gpio_led_data {
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struct led_classdev cdev;
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struct gpio_desc *gpiod;
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u8 can_sleep;
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u8 blinking;
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gpio_blink_set_t platform_gpio_blink_set;
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};
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static inline struct gpio_led_data *
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cdev_to_gpio_led_data(struct led_classdev *led_cdev)
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{
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return container_of(led_cdev, struct gpio_led_data, cdev);
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}
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static void gpio_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
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int level;
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if (value == LED_OFF)
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level = 0;
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else
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level = 1;
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if (led_dat->blinking) {
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led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
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NULL, NULL);
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led_dat->blinking = 0;
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} else {
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if (led_dat->can_sleep)
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gpiod_set_value_cansleep(led_dat->gpiod, level);
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else
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gpiod_set_value(led_dat->gpiod, level);
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}
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}
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static int gpio_led_set_blocking(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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gpio_led_set(led_cdev, value);
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return 0;
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}
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static int gpio_blink_set(struct led_classdev *led_cdev,
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unsigned long *delay_on, unsigned long *delay_off)
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{
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struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
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led_dat->blinking = 1;
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return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
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delay_on, delay_off);
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}
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static int create_gpio_led(const struct gpio_led *template,
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struct gpio_led_data *led_dat, struct device *parent,
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struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
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{
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struct led_init_data init_data = {};
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struct pinctrl *pinctrl;
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int ret, state;
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led_dat->cdev.default_trigger = template->default_trigger;
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led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
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if (!led_dat->can_sleep)
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led_dat->cdev.brightness_set = gpio_led_set;
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else
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led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
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led_dat->blinking = 0;
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if (blink_set) {
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led_dat->platform_gpio_blink_set = blink_set;
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led_dat->cdev.blink_set = gpio_blink_set;
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}
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if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
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state = gpiod_get_value_cansleep(led_dat->gpiod);
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if (state < 0)
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return state;
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} else {
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state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
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}
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led_dat->cdev.brightness = state;
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led_dat->cdev.max_brightness = 1;
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if (!template->retain_state_suspended)
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led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
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if (template->panic_indicator)
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led_dat->cdev.flags |= LED_PANIC_INDICATOR;
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if (template->retain_state_shutdown)
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led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
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ret = gpiod_direction_output(led_dat->gpiod, state);
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if (ret < 0)
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return ret;
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if (template->name) {
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led_dat->cdev.name = template->name;
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ret = devm_led_classdev_register(parent, &led_dat->cdev);
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} else {
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init_data.fwnode = fwnode;
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ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
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&init_data);
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}
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if (ret)
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return ret;
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pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
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ret = PTR_ERR_OR_ZERO(pinctrl);
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/* pinctrl-%d not present, not an error */
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if (ret == -ENODEV)
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ret = 0;
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if (ret) {
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dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
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fwnode, ret);
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}
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return ret;
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}
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struct gpio_leds_priv {
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int num_leds;
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struct gpio_led_data leds[] __counted_by(num_leds);
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};
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static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
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{
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struct fwnode_handle *child;
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struct gpio_leds_priv *priv;
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int count, ret;
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count = device_get_child_node_count(dev);
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if (!count)
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return ERR_PTR(-ENODEV);
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priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
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if (!priv)
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return ERR_PTR(-ENOMEM);
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device_for_each_child_node(dev, child) {
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struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
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struct gpio_led led = {};
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/*
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* Acquire gpiod from DT with uninitialized label, which
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* will be updated after LED class device is registered,
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* Only then the final LED name is known.
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*/
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led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS,
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NULL);
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if (IS_ERR(led.gpiod)) {
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dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
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child);
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fwnode_handle_put(child);
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return ERR_CAST(led.gpiod);
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}
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led_dat->gpiod = led.gpiod;
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led.default_state = led_init_default_state_get(child);
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if (fwnode_property_present(child, "retain-state-suspended"))
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led.retain_state_suspended = 1;
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if (fwnode_property_present(child, "retain-state-shutdown"))
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led.retain_state_shutdown = 1;
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if (fwnode_property_present(child, "panic-indicator"))
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led.panic_indicator = 1;
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ret = create_gpio_led(&led, led_dat, dev, child, NULL);
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if (ret < 0) {
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fwnode_handle_put(child);
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return ERR_PTR(ret);
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}
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/* Set gpiod label to match the corresponding LED name. */
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gpiod_set_consumer_name(led_dat->gpiod,
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led_dat->cdev.dev->kobj.name);
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priv->num_leds++;
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}
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return priv;
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}
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static const struct of_device_id of_gpio_leds_match[] = {
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{ .compatible = "gpio-leds", },
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{},
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};
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MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
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static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
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const struct gpio_led *template)
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{
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struct gpio_desc *gpiod;
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unsigned long flags = GPIOF_OUT_INIT_LOW;
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int ret;
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/*
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* This means the LED does not come from the device tree
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* or ACPI, so let's try just getting it by index from the
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* device, this will hit the board file, if any and get
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* the GPIO from there.
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*/
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gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW);
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if (IS_ERR(gpiod))
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return gpiod;
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if (gpiod) {
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gpiod_set_consumer_name(gpiod, template->name);
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return gpiod;
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}
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/*
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* This is the legacy code path for platform code that
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* still uses GPIO numbers. Ultimately we would like to get
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* rid of this block completely.
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*/
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/* skip leds that aren't available */
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if (!gpio_is_valid(template->gpio))
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return ERR_PTR(-ENOENT);
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if (template->active_low)
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flags |= GPIOF_ACTIVE_LOW;
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ret = devm_gpio_request_one(dev, template->gpio, flags,
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template->name);
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if (ret < 0)
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return ERR_PTR(ret);
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gpiod = gpio_to_desc(template->gpio);
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if (!gpiod)
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return ERR_PTR(-EINVAL);
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return gpiod;
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}
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static int gpio_led_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
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struct gpio_leds_priv *priv;
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int i, ret;
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if (pdata && pdata->num_leds) {
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priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->num_leds = pdata->num_leds;
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for (i = 0; i < priv->num_leds; i++) {
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const struct gpio_led *template = &pdata->leds[i];
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struct gpio_led_data *led_dat = &priv->leds[i];
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if (template->gpiod)
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led_dat->gpiod = template->gpiod;
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else
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led_dat->gpiod =
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gpio_led_get_gpiod(dev, i, template);
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if (IS_ERR(led_dat->gpiod)) {
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dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
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template->gpio, template->name);
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continue;
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}
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ret = create_gpio_led(template, led_dat, dev, NULL,
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pdata->gpio_blink_set);
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if (ret < 0)
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return ret;
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}
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} else {
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priv = gpio_leds_create(dev);
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if (IS_ERR(priv))
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return PTR_ERR(priv);
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}
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platform_set_drvdata(pdev, priv);
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return 0;
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}
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static void gpio_led_shutdown(struct platform_device *pdev)
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{
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struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
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int i;
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for (i = 0; i < priv->num_leds; i++) {
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struct gpio_led_data *led = &priv->leds[i];
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if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
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gpio_led_set(&led->cdev, LED_OFF);
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}
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}
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static struct platform_driver gpio_led_driver = {
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.probe = gpio_led_probe,
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.shutdown = gpio_led_shutdown,
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.driver = {
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.name = "leds-gpio",
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.of_match_table = of_gpio_leds_match,
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},
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};
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module_platform_driver(gpio_led_driver);
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MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
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MODULE_DESCRIPTION("GPIO LED driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:leds-gpio");
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