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Diffstat (limited to 'drivers/leds/leds-gpio.c')
-rw-r--r--drivers/leds/leds-gpio.c313
1 files changed, 313 insertions, 0 deletions
diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c
new file mode 100644
index 000000000..092eb59a7
--- /dev/null
+++ b/drivers/leds/leds-gpio.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * LEDs driver for GPIOs
+ *
+ * Copyright (C) 2007 8D Technologies inc.
+ * Raphael Assenat <raph@8d.com>
+ * Copyright (C) 2008 Freescale Semiconductor, Inc.
+ */
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include "leds.h"
+
+struct gpio_led_data {
+ struct led_classdev cdev;
+ struct gpio_desc *gpiod;
+ u8 can_sleep;
+ u8 blinking;
+ gpio_blink_set_t platform_gpio_blink_set;
+};
+
+static inline struct gpio_led_data *
+ cdev_to_gpio_led_data(struct led_classdev *led_cdev)
+{
+ return container_of(led_cdev, struct gpio_led_data, cdev);
+}
+
+static void gpio_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
+ int level;
+
+ if (value == LED_OFF)
+ level = 0;
+ else
+ level = 1;
+
+ if (led_dat->blinking) {
+ led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
+ NULL, NULL);
+ led_dat->blinking = 0;
+ } else {
+ if (led_dat->can_sleep)
+ gpiod_set_value_cansleep(led_dat->gpiod, level);
+ else
+ gpiod_set_value(led_dat->gpiod, level);
+ }
+}
+
+static int gpio_led_set_blocking(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ gpio_led_set(led_cdev, value);
+ return 0;
+}
+
+static int gpio_blink_set(struct led_classdev *led_cdev,
+ unsigned long *delay_on, unsigned long *delay_off)
+{
+ struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
+
+ led_dat->blinking = 1;
+ return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
+ delay_on, delay_off);
+}
+
+static int create_gpio_led(const struct gpio_led *template,
+ struct gpio_led_data *led_dat, struct device *parent,
+ struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
+{
+ struct led_init_data init_data = {};
+ int ret, state;
+
+ led_dat->cdev.default_trigger = template->default_trigger;
+ led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
+ if (!led_dat->can_sleep)
+ led_dat->cdev.brightness_set = gpio_led_set;
+ else
+ led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
+ led_dat->blinking = 0;
+ if (blink_set) {
+ led_dat->platform_gpio_blink_set = blink_set;
+ led_dat->cdev.blink_set = gpio_blink_set;
+ }
+ if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
+ state = gpiod_get_value_cansleep(led_dat->gpiod);
+ if (state < 0)
+ return state;
+ } else {
+ state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
+ }
+ led_dat->cdev.brightness = state;
+ led_dat->cdev.max_brightness = 1;
+ if (!template->retain_state_suspended)
+ led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
+ if (template->panic_indicator)
+ led_dat->cdev.flags |= LED_PANIC_INDICATOR;
+ if (template->retain_state_shutdown)
+ led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
+
+ ret = gpiod_direction_output(led_dat->gpiod, state);
+ if (ret < 0)
+ return ret;
+
+ if (template->name) {
+ led_dat->cdev.name = template->name;
+ ret = devm_led_classdev_register(parent, &led_dat->cdev);
+ } else {
+ init_data.fwnode = fwnode;
+ ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
+ &init_data);
+ }
+
+ return ret;
+}
+
+struct gpio_leds_priv {
+ int num_leds;
+ struct gpio_led_data leds[];
+};
+
+static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct fwnode_handle *child;
+ struct gpio_leds_priv *priv;
+ int count, ret;
+
+ count = device_get_child_node_count(dev);
+ if (!count)
+ return ERR_PTR(-ENODEV);
+
+ priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
+ if (!priv)
+ return ERR_PTR(-ENOMEM);
+
+ device_for_each_child_node(dev, child) {
+ struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];
+ struct gpio_led led = {};
+
+ /*
+ * Acquire gpiod from DT with uninitialized label, which
+ * will be updated after LED class device is registered,
+ * Only then the final LED name is known.
+ */
+ led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
+ GPIOD_ASIS,
+ NULL);
+ if (IS_ERR(led.gpiod)) {
+ fwnode_handle_put(child);
+ return ERR_CAST(led.gpiod);
+ }
+
+ led_dat->gpiod = led.gpiod;
+
+ led.default_state = led_init_default_state_get(child);
+
+ if (fwnode_property_present(child, "retain-state-suspended"))
+ led.retain_state_suspended = 1;
+ if (fwnode_property_present(child, "retain-state-shutdown"))
+ led.retain_state_shutdown = 1;
+ if (fwnode_property_present(child, "panic-indicator"))
+ led.panic_indicator = 1;
+
+ ret = create_gpio_led(&led, led_dat, dev, child, NULL);
+ if (ret < 0) {
+ fwnode_handle_put(child);
+ return ERR_PTR(ret);
+ }
+ /* Set gpiod label to match the corresponding LED name. */
+ gpiod_set_consumer_name(led_dat->gpiod,
+ led_dat->cdev.dev->kobj.name);
+ priv->num_leds++;
+ }
+
+ return priv;
+}
+
+static const struct of_device_id of_gpio_leds_match[] = {
+ { .compatible = "gpio-leds", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
+
+static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
+ const struct gpio_led *template)
+{
+ struct gpio_desc *gpiod;
+ unsigned long flags = GPIOF_OUT_INIT_LOW;
+ int ret;
+
+ /*
+ * This means the LED does not come from the device tree
+ * or ACPI, so let's try just getting it by index from the
+ * device, this will hit the board file, if any and get
+ * the GPIO from there.
+ */
+ gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW);
+ if (!IS_ERR(gpiod)) {
+ gpiod_set_consumer_name(gpiod, template->name);
+ return gpiod;
+ }
+ if (PTR_ERR(gpiod) != -ENOENT)
+ return gpiod;
+
+ /*
+ * This is the legacy code path for platform code that
+ * still uses GPIO numbers. Ultimately we would like to get
+ * rid of this block completely.
+ */
+
+ /* skip leds that aren't available */
+ if (!gpio_is_valid(template->gpio))
+ return ERR_PTR(-ENOENT);
+
+ if (template->active_low)
+ flags |= GPIOF_ACTIVE_LOW;
+
+ ret = devm_gpio_request_one(dev, template->gpio, flags,
+ template->name);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ gpiod = gpio_to_desc(template->gpio);
+ if (!gpiod)
+ return ERR_PTR(-EINVAL);
+
+ return gpiod;
+}
+
+static int gpio_led_probe(struct platform_device *pdev)
+{
+ struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct gpio_leds_priv *priv;
+ int i, ret = 0;
+
+ if (pdata && pdata->num_leds) {
+ priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds),
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->num_leds = pdata->num_leds;
+ for (i = 0; i < priv->num_leds; i++) {
+ const struct gpio_led *template = &pdata->leds[i];
+ struct gpio_led_data *led_dat = &priv->leds[i];
+
+ if (template->gpiod)
+ led_dat->gpiod = template->gpiod;
+ else
+ led_dat->gpiod =
+ gpio_led_get_gpiod(&pdev->dev,
+ i, template);
+ if (IS_ERR(led_dat->gpiod)) {
+ dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n",
+ template->gpio, template->name);
+ continue;
+ }
+
+ ret = create_gpio_led(template, led_dat,
+ &pdev->dev, NULL,
+ pdata->gpio_blink_set);
+ if (ret < 0)
+ return ret;
+ }
+ } else {
+ priv = gpio_leds_create(pdev);
+ if (IS_ERR(priv))
+ return PTR_ERR(priv);
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static void gpio_led_shutdown(struct platform_device *pdev)
+{
+ struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < priv->num_leds; i++) {
+ struct gpio_led_data *led = &priv->leds[i];
+
+ if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
+ gpio_led_set(&led->cdev, LED_OFF);
+ }
+}
+
+static struct platform_driver gpio_led_driver = {
+ .probe = gpio_led_probe,
+ .shutdown = gpio_led_shutdown,
+ .driver = {
+ .name = "leds-gpio",
+ .of_match_table = of_gpio_leds_match,
+ },
+};
+
+module_platform_driver(gpio_led_driver);
+
+MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
+MODULE_DESCRIPTION("GPIO LED driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:leds-gpio");