// 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/container_of.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/leds.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/types.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 = {};
        struct pinctrl *pinctrl;
        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);
        }

        if (ret)
                return ret;

        pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
        ret = PTR_ERR_OR_ZERO(pinctrl);
        /* pinctrl-%d not present, not an error */
        if (ret == -ENODEV)
                ret = 0;
        if (ret) {
                dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
                         fwnode, ret);
        }

        return ret;
}

struct gpio_leds_priv {
        int num_leds;
        struct gpio_led_data leds[] __counted_by(num_leds);
};

static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
{
        struct gpio_leds_priv *priv;
        int count, used, 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);
        priv->num_leds = count;
        used = 0;

        device_for_each_child_node_scoped(dev, child) {
                struct gpio_led_data *led_dat = &priv->leds[used];
                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_gpiod_get(dev, child, NULL, GPIOD_ASIS,
                                                  NULL);
                if (IS_ERR(led.gpiod)) {
                        dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
                                      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)
                        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);
                used++;
        }
        priv->num_leds = used;

        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;
        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_optional(dev, NULL, idx, GPIOD_OUT_LOW);
        if (IS_ERR(gpiod))
                return gpiod;
        if (gpiod) {
                gpiod_set_consumer_name(gpiod, template->name);
                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);

        ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW,
                                    template->name);
        if (ret < 0)
                return ERR_PTR(ret);

        gpiod = gpio_to_desc(template->gpio);
        if (!gpiod)
                return ERR_PTR(-EINVAL);

        if (template->active_low ^ gpiod_is_active_low(gpiod))
                gpiod_toggle_active_low(gpiod);

        return gpiod;
}

static int gpio_led_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
        struct gpio_leds_priv *priv;
        int i, ret;

        if (pdata && pdata->num_leds) {
                priv = devm_kzalloc(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(dev, i, template);
                        if (IS_ERR(led_dat->gpiod)) {
                                dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
                                         template->gpio, template->name);
                                continue;
                        }

                        ret = create_gpio_led(template, led_dat, dev, NULL,
                                              pdata->gpio_blink_set);
                        if (ret < 0)
                                return ret;
                }
        } else {
                priv = gpio_leds_create(dev);
                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");