Re: [PATCH v4 3/3] leds: Add ktd2692 flash LED driver

[Varka Bhadram <varkabhadram@gmail.com>]

On 03/25/2015 07:00 AM, Ingi Kim wrote:

> This patch adds a driver to support the ktd2692 flash LEDs.
> ktd2692 can control flash current by ExpressWire interface.
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> ---
>   drivers/leds/Kconfig        |   9 +
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-ktd2692.c | 412 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 422 insertions(+)
>   create mode 100644 drivers/leds/leds-ktd2692.c
>
(...)

> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
> +				u32 *flash_timeout_us)
> +{
> +	struct device_node *np = dev->of_node;
> +

Unnecessary one line space..

> +	int ret;
> +
> +	led->ctrl_gpio = of_get_named_gpio(np, "ctrl-gpio", 0);
> +	if (!gpio_is_valid(led->ctrl_gpio)) {
> +		dev_err(dev, "no ctrl-gpio property found\n");
> +		return -EINVAL;
> +	}
> +
> +	led->aux_gpio = of_get_named_gpio(np, "aux-gpio", 0);
> +	if (!gpio_is_valid(led->aux_gpio)) {
> +		dev_err(dev, "no aux-gpio property found\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = devm_gpio_request_one(dev, led->ctrl_gpio,
> +					GPIOF_OPEN_SOURCE, "ctrl-gpio");
> +	if (ret) {
> +		dev_err(dev, "failed to request ctrl-gpio %d error %d\n",
> +				led->ctrl_gpio, ret);
> +		return ret;
> +	}
> +
> +	ret = devm_gpio_request_one(dev, led->aux_gpio,
> +					GPIOF_OPEN_SOURCE, "aux-gpio");
> +	if (ret) {
> +		dev_err(dev, "failed to request aux-gpio %d error %d\n",
> +				led->aux_gpio, ret);
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(np, "flash-timeout-us", flash_timeout_us);
> +	/* default setting */
> +	if (ret)
> +		*flash_timeout_us = KTD2692_FLASH_MODE_TIMEOUT_DEFAULT_US;
> +
> +	return 0;
> +}
> +
> +static const struct led_flash_ops flash_ops = {
> +	.strobe_set = ktd2692_led_flash_strobe_set,
> +	.timeout_set = ktd2692_led_flash_timeout_set,
> +};
> +
> +static int ktd2692_probe(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led;
> +	struct led_classdev *led_cdev;
> +	struct led_classdev_flash *fled_cdev;
> +	struct led_flash_setting flash_timeout;
> +	u32 flash_timeout_us;
> +	int ret;
> +
> +	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	if (!pdev->dev.of_node)
> +		return -ENXIO;
> +

Above operation dt related. So if you do that in ktd2692_parse_dt(), it will be good

> +	fled_cdev = &led->fled_cdev;
> +	led_cdev = &fled_cdev->led_cdev;
> +
> +	ret = ktd2692_parse_dt(led, &pdev->dev, &flash_timeout_us);
> +	if (ret)
> +		return ret;
> +
> +	led->regulator = devm_regulator_get(&pdev->dev, "vin");
> +	if (IS_ERR(led->regulator)) {
> +		dev_err(&pdev->dev, "regulator get failed\n");
> +		return PTR_ERR(led->regulator);
> +	}
> +
> +	ktd2692_init_flash_timeout(flash_timeout_us, &flash_timeout);
> +
> +	fled_cdev->timeout = flash_timeout;
> +	fled_cdev->ops = &flash_ops;
> +
> +	led_cdev->name = KTD2692_DEFAULT_NAME;
> +	led_cdev->brightness_set = ktd2692_led_brightness_set;
> +	led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
> +	led_cdev->flags |= LED_CORE_SUSPENDRESUME;
> +	led_cdev->flags |= LED_DEV_CAP_FLASH;
> +
> +	mutex_init(&led->lock);
> +	INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
> +
> +	platform_set_drvdata(pdev, led);
> +
> +	ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
> +		cancel_work_sync(&led->work_brightness_set);

Is the above API is correct to use in this place.?

cancel_work_sync — cancel a work and wait for it to finish...

Work is not yet scheduled..?

What about mutex destroy..?

> +		return ret;
> +	}
> +
> +	ktd2692_setup(led);
> +	ktd2692_led_regulator_enable(led);
> +
> +	return 0;
> +}
> +
> +static int ktd2692_remove(struct platform_device *pdev)
> +{
> +	struct ktd2692_context *led = platform_get_drvdata(pdev);
> +
> +	ktd2692_led_regulator_disable(led);
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +	cancel_work_sync(&led->work_brightness_set);
> +
> +	mutex_destroy(&led->lock);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id ktd2692_match[] = {
> +	{ .compatible = "kinetic,ktd2692", },
> +	{ /* sentinel */ },
> +};
> +
> +static struct platform_driver ktd2692_driver = {
> +	.driver = {
> +		.name  = "leds-ktd2692",
> +		.of_match_table = ktd2692_match,
> +	},
> +	.probe  = ktd2692_probe,
> +	.remove = ktd2692_remove,
> +};
> +
> +module_platform_driver(ktd2692_driver);
> +
> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
> +MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
> +MODULE_LICENSE("GPL v2");


-- 
Varka Bhadram