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    Subject[PATCH 3/3] leds: add sgm3140 driver
    Date
    Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.

    This device is controlled by two GPIO pins, one for enabling and the
    second one for switching between torch and flash mode.

    Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
    ---
    Changes since RFC:
    - address review comments from Jacek Anaszewski:
    - implement strobe_get op
    - implement timeout_set op
    - init v4l2_sd_cfg variable
    - remove init_data.devicename assignemnt
    - use devm_ version of led_classdev_flash_register_ext
    - release child_node in case of success

    drivers/leds/Kconfig | 9 ++
    drivers/leds/Makefile | 1 +
    drivers/leds/leds-sgm3140.c | 260 ++++++++++++++++++++++++++++++++++++
    3 files changed, 270 insertions(+)
    create mode 100644 drivers/leds/leds-sgm3140.c

    diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
    index 4b68520ac251..9206fc66799d 100644
    --- a/drivers/leds/Kconfig
    +++ b/drivers/leds/Kconfig
    @@ -836,6 +836,15 @@ config LEDS_LM36274
    Say Y to enable the LM36274 LED driver for TI LMU devices.
    This supports the LED device LM36274.

    +config LEDS_SGM3140
    + tristate "LED support for the SGM3140"
    + depends on LEDS_CLASS_FLASH
    + depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
    + depends on OF
    + help
    + This option enables support for the SGM3140 500mA Buck/Boost Charge
    + Pump LED Driver.
    +
    comment "LED Triggers"
    source "drivers/leds/trigger/Kconfig"

    diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
    index 2da39e896ce8..38d57dd53e4b 100644
    --- a/drivers/leds/Makefile
    +++ b/drivers/leds/Makefile
    @@ -85,6 +85,7 @@ obj-$(CONFIG_LEDS_LM3601X) += leds-lm3601x.o
    obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
    obj-$(CONFIG_LEDS_LM3697) += leds-lm3697.o
    obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o
    +obj-$(CONFIG_LEDS_SGM3140) += leds-sgm3140.o

    # LED SPI Drivers
    obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
    diff --git a/drivers/leds/leds-sgm3140.c b/drivers/leds/leds-sgm3140.c
    new file mode 100644
    index 000000000000..357f4cbb279a
    --- /dev/null
    +++ b/drivers/leds/leds-sgm3140.c
    @@ -0,0 +1,260 @@
    +// SPDX-License-Identifier: GPL-2.0
    +// Copyright (C) 2020 Luca Weiss <luca@z3ntu.xyz>
    +
    +#include <linux/gpio/consumer.h>
    +#include <linux/led-class-flash.h>
    +#include <linux/module.h>
    +#include <linux/of.h>
    +#include <linux/platform_device.h>
    +
    +#include <media/v4l2-flash-led-class.h>
    +
    +#define FLASH_TIMEOUT_DEFAULT 250000 /* 250ms */
    +#define FLASH_MAX_TIMEOUT_DEFAULT 300000 /* 300ms */
    +
    +struct sgm3140 {
    + struct gpio_desc *flash_gpio;
    + struct gpio_desc *enable_gpio;
    +
    + /* current timeout in us */
    + u32 timeout;
    + /* maximum timeout in us */
    + u32 max_timeout;
    +
    + struct led_classdev_flash fled_cdev;
    + struct v4l2_flash *v4l2_flash;
    +
    + struct timer_list powerdown_timer;
    +};
    +
    +static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
    +{
    + return container_of(flcdev, struct sgm3140, fled_cdev);
    +}
    +
    +static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
    +{
    + struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
    +
    + if (state) {
    + gpiod_set_value_cansleep(priv->flash_gpio, 1);
    + gpiod_set_value_cansleep(priv->enable_gpio, 1);
    + mod_timer(&priv->powerdown_timer,
    + jiffies + usecs_to_jiffies(priv->timeout));
    + } else {
    + gpiod_set_value_cansleep(priv->enable_gpio, 0);
    + gpiod_set_value_cansleep(priv->flash_gpio, 0);
    + del_timer_sync(&priv->powerdown_timer);
    + }
    +
    + return 0;
    +}
    +
    +static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
    +{
    + struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
    +
    + *state = timer_pending(&priv->powerdown_timer);
    +
    + return 0;
    +}
    +
    +static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev, u32 timeout)
    +{
    + struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
    +
    + priv->timeout = timeout;
    +
    + return 0;
    +}
    +
    +struct led_flash_ops sgm3140_flash_ops = {
    + .strobe_set = sgm3140_strobe_set,
    + .strobe_get = sgm3140_strobe_get,
    + .timeout_set = sgm3140_timeout_set,
    +};
    +
    +int sgm3140_brightness_set(struct led_classdev *led_cdev,
    + enum led_brightness brightness)
    +{
    + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
    + struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
    +
    + if (brightness == LED_OFF)
    + gpiod_set_value_cansleep(priv->enable_gpio, 0);
    + else
    + gpiod_set_value_cansleep(priv->enable_gpio, 1);
    +
    + return 0;
    +}
    +
    +static void sgm3140_powerdown_timer(struct timer_list *t)
    +{
    + struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
    +
    + gpiod_set_value_cansleep(priv->enable_gpio, 0);
    + gpiod_set_value_cansleep(priv->flash_gpio, 0);
    +}
    +
    +static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
    +{
    + struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
    + struct led_flash_setting *s;
    +
    + /* Init flash timeout setting */
    + s = &fled_cdev->timeout;
    + s->min = 1;
    + s->max = priv->max_timeout;
    + s->step = 1;
    + s->val = FLASH_TIMEOUT_DEFAULT;
    +}
    +
    +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
    +static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
    + struct v4l2_flash_config *v4l2_sd_cfg)
    +{
    + struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
    + struct led_flash_setting *s;
    +
    + strlcpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
    + sizeof(v4l2_sd_cfg->dev_name));
    +
    + /* Init flash intensity setting */
    + s = &v4l2_sd_cfg->intensity;
    + s->min = 0;
    + s->max = 1;
    + s->step = 1;
    + s->val = 1;
    +}
    +
    +#else
    +static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
    + struct v4l2_flash_config *v4l2_sd_cfg)
    +{
    +}
    +#endif
    +
    +static int sgm3140_probe(struct platform_device *pdev)
    +{
    + struct sgm3140 *priv;
    + struct led_classdev *led_cdev;
    + struct led_classdev_flash *fled_cdev;
    + struct led_init_data init_data = {};
    + struct device_node *child_node;
    + struct v4l2_flash_config v4l2_sd_cfg = {};
    + int ret;
    +
    + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
    + if (!priv)
    + return -ENOMEM;
    +
    + priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
    + ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
    + if (ret) {
    + if (ret != -EPROBE_DEFER)
    + dev_err(&pdev->dev, "Failed to request flash gpio: %d\n",
    + ret);
    + return ret;
    + }
    +
    + priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
    + ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
    + if (ret) {
    + if (ret != -EPROBE_DEFER)
    + dev_err(&pdev->dev, "Failed to request enable gpio: %d\n",
    + ret);
    + return ret;
    + }
    +
    + child_node = of_get_next_available_child(pdev->dev.of_node, NULL);
    + if (!child_node) {
    + dev_err(&pdev->dev, "No DT child node found for connected LED.\n");
    + return -EINVAL;
    + }
    +
    +
    + ret = of_property_read_u32(child_node, "flash-max-timeout-us",
    + &priv->max_timeout);
    + if (ret < 0) {
    + priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
    + dev_warn(&pdev->dev, "flash-max-timeout-us DT property missing\n");
    + }
    +
    + /*
    + * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
    + * from DT is lower.
    + */
    + priv->timeout = min(priv->max_timeout, (u32)FLASH_TIMEOUT_DEFAULT);
    +
    + timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);
    +
    + fled_cdev = &priv->fled_cdev;
    + led_cdev = &fled_cdev->led_cdev;
    +
    + fled_cdev->ops = &sgm3140_flash_ops;
    +
    + led_cdev->brightness_set_blocking = sgm3140_brightness_set;
    + led_cdev->max_brightness = LED_ON;
    + led_cdev->flags |= LED_DEV_CAP_FLASH;
    +
    + sgm3140_init_flash_timeout(priv);
    +
    + init_data.fwnode = of_fwnode_handle(child_node);
    +
    + platform_set_drvdata(pdev, priv);
    +
    + /* Register in the LED subsystem */
    + ret = devm_led_classdev_flash_register_ext(&pdev->dev, fled_cdev, &init_data);
    + if (ret < 0) {
    + dev_err(&pdev->dev, "Failed to register flash device: %d\n",
    + ret);
    + goto err;
    + }
    +
    + sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);
    +
    + /* Create V4L2 Flash subdev */
    + priv->v4l2_flash = v4l2_flash_init(&pdev->dev, of_fwnode_handle(child_node),
    + fled_cdev, NULL,
    + &v4l2_sd_cfg);
    + if (IS_ERR(priv->v4l2_flash)) {
    + ret = PTR_ERR(priv->v4l2_flash);
    + goto err;
    + }
    +
    +err:
    + of_node_put(child_node);
    + return ret;
    +}
    +
    +static int sgm3140_remove(struct platform_device *pdev)
    +{
    + struct sgm3140 *priv = platform_get_drvdata(pdev);
    +
    + del_timer_sync(&priv->powerdown_timer);
    +
    + v4l2_flash_release(priv->v4l2_flash);
    +
    + return 0;
    +}
    +
    +static const struct of_device_id sgm3140_dt_match[] = {
    + { .compatible = "sgmicro,sgm3140" },
    + { /* sentinel */ }
    +};
    +MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
    +
    +static struct platform_driver sgm3140_driver = {
    + .probe = sgm3140_probe,
    + .remove = sgm3140_remove,
    + .driver = {
    + .name = "sgm3140",
    + .of_match_table = sgm3140_dt_match,
    + },
    +};
    +
    +module_platform_driver(sgm3140_driver);
    +
    +MODULE_AUTHOR("Luca Weiss <luca@z3ntu.xyz>");
    +MODULE_DESCRIPTION("SG Micro SGM3140 charge pump led driver");
    +MODULE_LICENSE("GPL v2");
    --
    2.25.1
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      Last update: 2020-03-09 21:37    [W:3.337 / U:0.052 seconds]
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