Re: [PATCH v2 3/3] leds: rt5033: Add RT5033 Flash led device driver

[Jacek Anaszewski <j.anaszewski@samsung.com>]

Hi Ingi,

Thanks for the update. Few comments below.

On 10/12/2015 03:12 PM, Ingi Kim wrote:
> This patch adds device driver of Richtek RT5033 PMIC.
> The driver supports a current regulated output to drive
> white LEDs for camera flash.
>
> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
> ---
>   drivers/leds/Kconfig               |   8 ++
>   drivers/leds/Makefile              |   1 +
>   drivers/leds/leds-rt5033.c         | 223 +++++++++++++++++++++++++++++++++++++
>   include/linux/mfd/rt5033-private.h |  49 ++++++++
>   include/linux/mfd/rt5033.h         |  22 +++-
>   5 files changed, 301 insertions(+), 2 deletions(-)
>   create mode 100644 drivers/leds/leds-rt5033.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 42990f2..29613e3 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -345,6 +345,14 @@ config LEDS_PCA963X
>   	  LED driver chip accessed via the I2C bus. Supported
>   	  devices include PCA9633 and PCA9634
>
> +config LEDS_RT5033
> +	tristate "LED support for RT5033 PMIC"
> +	depends on LEDS_CLASS_FLASH && OF
> +	depends on MFD_RT5033
> +	help
> +	  This option enables support for on-chip LED driver on
> +	  RT5033 PMIC.
> +
>   config LEDS_WM831X_STATUS
>   	tristate "LED support for status LEDs on WM831x PMICs"
>   	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index b503f92..bcc4d93 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_LEDS_COBALT_QUBE)		+= leds-cobalt-qube.o
>   obj-$(CONFIG_LEDS_COBALT_RAQ)		+= leds-cobalt-raq.o
>   obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o
>   obj-$(CONFIG_LEDS_PCA9532)		+= leds-pca9532.o
> +obj-$(CONFIG_LEDS_RT5033)		+= leds-rt5033.o
>   obj-$(CONFIG_LEDS_GPIO_REGISTER)	+= leds-gpio-register.o
>   obj-$(CONFIG_LEDS_GPIO)			+= leds-gpio.o
>   obj-$(CONFIG_LEDS_LP3944)		+= leds-lp3944.o
> diff --git a/drivers/leds/leds-rt5033.c b/drivers/leds/leds-rt5033.c
> new file mode 100644
> index 0000000..b470c94
> --- /dev/null
> +++ b/drivers/leds/leds-rt5033.c
> @@ -0,0 +1,223 @@
> +/*
> + * led driver for RT5033
> + *
> + * Copyright (C) 2015 Samsung Electronics, Co., Ltd.
> + * Ingi Kim <ingi2.kim@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/mfd/rt5033.h>
> +#include <linux/mfd/rt5033-private.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#define RT5033_LED_FLASH_TIMEOUT_MIN		64000
> +#define RT5033_LED_FLASH_TIMEOUT_STEPS		32000
> +#define RT5033_LED_TORCH_CURRENT_LEVEL_MAX	16
> +
> +/* Macro for getting offset of flash timeout */
> +#define GET_TIMEOUT_OFFSET(tm, step)	((tm) / (step) - 2)
> +
> +static struct rt5033_led *flcdev_to_led(
> +				struct led_classdev_flash *fled_cdev)
> +{
> +	return container_of(fled_cdev, struct rt5033_led, fled_cdev);
> +}
> +
> +static int rt5033_led_brightness_set(struct led_classdev *led_cdev,
> +				     enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
> +	struct rt5033_led *led = flcdev_to_led(fled_cdev);

I assume that you don't use mutex here deliberately?

> +	if (!brightness) {
> +		regmap_update_bits(led->regmap, RT5033_REG_FLED_FUNCTION2,
> +				   RT5033_FLED_CTRL2_MASK, 0x0);
> +	} else {
> +		regmap_update_bits(led->regmap, RT5033_REG_FLED_FUNCTION1,
> +				   RT5033_FLED_FUNC1_MASK, RT5033_FLED_PINCTRL);
> +		regmap_update_bits(led->regmap,	RT5033_REG_FLED_CTRL1,
> +				   RT5033_FLED_CTRL1_MASK,
> +				   (brightness - 1) << 4);
> +		regmap_update_bits(led->regmap, RT5033_REG_FLED_FUNCTION2,
> +				   RT5033_FLED_CTRL2_MASK, RT5033_FLED_ENFLED);
> +	}
> +
> +	return 0;
> +}
> +
> +static void rt5033_init_flash_timeout(struct rt5033_led *led)
> +{
> +	struct led_flash_setting *setting;
> +
> +	setting = &led->fled_cdev.timeout;
> +	setting->min = RT5033_LED_FLASH_TIMEOUT_MIN;
> +	setting->max = led->data->flash_max_timeout;
> +	setting->step = RT5033_LED_FLASH_TIMEOUT_STEPS;
> +	setting->val = led->data->flash_max_timeout;
> +}
> +
> +static int rt5033_led_parse_dt(struct rt5033_led *led, struct device *dev)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct device_node *child_node;
> +	struct rt5033_led_config_data *data;
> +	int ret = 0;
> +
> +	if (!np)
> +		return -ENXIO;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;

This way data will remain allocated until driver removal, whereas
you are using it only in rt5033_init_flash_timeout during driver
probing AFAICS. Please define local variable in rt5033_led_probe,
pass its pointer to this function and than pass the pointer to
rt5033_init_flash_timeout.

> +	child_node = of_get_next_available_child(np, NULL);
> +	if (!child_node) {
> +		dev_err(dev, "DT child node isn't found\n");
> +		return -EINVAL;
> +	}
> +
> +	led->fled_cdev.led_cdev.name =
> +		of_get_property(child_node, "label", NULL) ? : child_node->name;
> +
> +	ret = of_property_read_u32(child_node, "led-max-microamp",
> +				   &data->torch_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse led-max-microamp\n");
> +		return ret;
> +	}

data->torch_max_microamp isn't used anywhere, while it should be used
for initializing led_cdev->max_brightness.

> +
> +	ret = of_property_read_u32(child_node, "flash-max-microamp",
> +				   &data->flash_max_microamp);
> +	if (ret) {
> +		dev_err(dev, "failed to parse flash-max-microamp\n");
> +		return ret;
> +	}

data->flash_max_microamp also isn't used anywhere. Does your device
support flash brightness setting? If yes then you should implement
also flash_brightness_set op. Otherwise this property is redundant.

> +	ret = of_property_read_u32(child_node, "flash-max-timeout-us",
> +				   &data->flash_max_timeout);
> +	if (ret)
> +		dev_err(dev, "failed to parse flash-max-timeout-us\n");
> +
> +	of_node_put(child_node);
> +	led->data = data;
> +
> +	return ret;
> +}
> +
> +static int rt5033_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
> +					u32 timeout)
> +{
> +	return 0;
> +}
> +
> +static int rt5033_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
> +				       bool state)
> +{
> +	struct rt5033_led *led = flcdev_to_led(fled_cdev);
> +	u32 flash_tm_reg;

I think that you need a mutex here and in rt5033_led_flash_strobe_set. 
Otherwise following is possible:

Process 1:
	rt5033_led_flash_strobe_set(led_cdev, 1);

	regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION1,
			RT5033_FLED_FUNC1_MASK, RT5033_FLED_RESET);
	fled_cdev->led_cdev.brightness = LED_OFF;

Process 2:
	led_set_brightness(led_cdev, 1);

	fled_cdev->led_cdev.brightness = 1;

	rt5033_led_brightness_set(led_cdev, LED_FULL);

	regmap_update_bits(led->regmap, RT5033_REG_FLED_FUNCTION1,
			RT5033_FLED_FUNC1_MASK, RT5033_FLED_PINCTRL);
	regmap_update_bits(led->regmap,	RT5033_REG_FLED_CTRL1,
			RT5033_FLED_CTRL1_MASK,
			(brightness - 1) << 4);
	regmap_update_bits(led->regmap, RT5033_REG_FLED_FUNCTION2,
			RT5033_FLED_CTRL2_MASK, RT5033_FLED_ENFLED);

Process 1:
	regmap_update_bits(led->regmap,	RT5033_REG_FLED_STROBE_CTRL2,
		RT5033_FLED_STRBCTRL2_MASK, flash_tm_reg);
	regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION1,
		RT5033_FLED_FUNC1_MASK, RT5033_FLED_STRB_SEL
		| RT5033_FLED_PINCTRL);
	regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION2,
		RT5033_FLED_FUNC2_MASK, RT5033_FLED_ENFLED

In a result LED class device will report brightness value 1,
whereas it would be inconsistent with hardware state, since
flash strobe turns torch mode off.


> +
> +	regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION1,
> +			   RT5033_FLED_FUNC1_MASK, RT5033_FLED_RESET);
> +	fled_cdev->led_cdev.brightness = LED_OFF;
 > +
> +	if (state) {
> +		flash_tm_reg = GET_TIMEOUT_OFFSET(fled_cdev->timeout.val,
> +						  fled_cdev->timeout.step);
> +		regmap_update_bits(led->regmap,	RT5033_REG_FLED_STROBE_CTRL2,
> +				   RT5033_FLED_STRBCTRL2_MASK, flash_tm_reg);
> +		regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION1,
> +				   RT5033_FLED_FUNC1_MASK, RT5033_FLED_STRB_SEL
> +				   | RT5033_FLED_PINCTRL);
> +		regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION2,
> +				   RT5033_FLED_FUNC2_MASK, RT5033_FLED_ENFLED
> +				   | RT5033_FLED_SREG_STRB);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct led_flash_ops flash_ops = {
> +	.strobe_set = rt5033_led_flash_strobe_set,
> +	.timeout_set = rt5033_led_flash_timeout_set,
> +};
> +
> +static int rt5033_led_probe(struct platform_device *pdev)
> +{
> +	struct rt5033_dev *rt5033 = dev_get_drvdata(pdev->dev.parent);
> +	struct rt5033_led *led;
> +	struct led_classdev *led_cdev;
> +	int ret;
> +
> +	led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, led);
> +	led->dev = &pdev->dev;
> +	led->regmap = rt5033->regmap;
> +
> +	ret = rt5033_led_parse_dt(led, &pdev->dev);
> +	if (ret)
> +		return ret;
> +
> +	rt5033_init_flash_timeout(led);
> +	led->fled_cdev.ops = &flash_ops;
> +	led_cdev = &led->fled_cdev.led_cdev;
> +
> +	led_cdev->max_brightness = RT5033_LED_TORCH_CURRENT_LEVEL_MAX;

This should depend on led-max-microamp.

> +	led_cdev->brightness_set_sync = rt5033_led_brightness_set;
> +	led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;

You need also a work queue since your ops can sleep.

> +
> +	ret = led_classdev_flash_register(&pdev->dev, &led->fled_cdev);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
> +		return ret;
> +	}
> +
> +	regmap_update_bits(led->regmap,	RT5033_REG_FLED_FUNCTION1,
> +			   RT5033_FLED_FUNC1_MASK, RT5033_FLED_RESET);
> +
> +	return 0;
> +}
> +
> +static int rt5033_led_remove(struct platform_device *pdev)
> +{
> +	struct rt5033_led *led = platform_get_drvdata(pdev);
> +
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +
> +	return 0;
> +}
> +
> +static const struct platform_device_id rt5033_led_id[] = {
> +	{ "rt5033-led", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(platform, rt5033_led_id);
> +
> +static const struct of_device_id rt5033_led_match[] = {
> +	{ .compatible = "richtek,rt5033-led", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, rt5033_led_match);
> +
> +static struct platform_driver rt5033_led_driver = {
> +	.driver = {
> +		.name = "rt5033-led",
> +		.of_match_table = rt5033_led_match,
> +	},
> +	.probe		= rt5033_led_probe,
> +	.id_table	= rt5033_led_id,
> +	.remove		= rt5033_led_remove,
> +};
> +module_platform_driver(rt5033_led_driver);
> +
> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
> +MODULE_DESCRIPTION("Richtek RT5033 LED driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:rt5033-led");
> diff --git a/include/linux/mfd/rt5033-private.h b/include/linux/mfd/rt5033-private.h
> index 1b63fc2..c8e99e4 100644
> --- a/include/linux/mfd/rt5033-private.h
> +++ b/include/linux/mfd/rt5033-private.h
> @@ -93,6 +93,55 @@ enum rt5033_reg {
>   #define RT5033_RT_CTRL1_UUG_MASK	0x02
>   #define RT5033_RT_HZ_MASK		0x01
>
> +/* RT5033 FLED Function1 register */
> +#define RT5033_FLED_FUNC1_MASK		0x94
> +#define RT5033_FLED_STRB_SEL		0x04
> +#define RT5033_FLED_PINCTRL		0x10
> +#define RT5033_FLED_RESET		0x80
> +
> +/* RT5033 FLED Function2 register */
> +#define RT5033_FLED_FUNC2_MASK		0x81
> +#define RT5033_FLED_ENFLED		0x01
> +#define RT5033_FLED_SREG_STRB		0x80
> +
> +/* RT5033 FLED Strobe Control1 */
> +#define RT5033_FLED_STRBCTRL1_MASK		0xFF
> +#define RT5033_FLED_STRBCTRL1_TM_CUR_MAX	0xE0
> +#define RT5033_FLED_STRBCTRL1_FL_CUR_DEF	0x0D
> +#define RT5033_FLED_STRBCTRL1_FL_CUR_MAX	0x1F
> +
> +/* RT5033 FLED Strobe Control2 */
> +#define RT5033_FLED_STRBCTRL2_MASK	0x3F
> +#define RT5033_FLED_STRBCTRL2_TM_DEF	0x0F
> +#define RT5033_FLED_STRBCTRL2_TM_MAX	0x3F
> +
> +/* RT5033 FLED Control1 */
> +#define RT5033_FLED_CTRL1_MASK		0xF7
> +#define RT5033_FLED_CTRL1_TORCH_CUR_DEF	0x20
> +#define RT5033_FLED_CTRL1_TORCH_CUR_MAX	0xF0
> +#define RT5033_FLED_CTRL1_LBP_DEF	0x02
> +#define RT5033_FLED_CTRL1_LBP_MAX	0x07
> +
> +/* RT5033 FLED Control2 */
> +#define RT5033_FLED_CTRL2_MASK		0xFF
> +#define RT5033_FLED_CTRL2_VMID_DEF	0x37
> +#define RT5033_FLED_CTRL2_VMID_MAX	0x3F
> +#define RT5033_FLED_CTRL2_TRACK_ALIVE	0x40
> +#define RT5033_FLED_CTRL2_MID_TRACK	0x80
> +
> +/* RT5033 FLED Control4 */
> +#define RT5033_FLED_CTRL4_MASK		0xE0
> +#define RT5033_FLED_CTRL4_RESV		0x14
> +#define RT5033_FLED_CTRL4_VTRREG_DEF	0x40
> +#define RT5033_FLED_CTRL4_VTRREG_MAX	0x60
> +#define RT5033_FLED_CTRL4_TRACK_CLK	0x80
> +
> +/* RT5033 FLED Control5 */
> +#define RT5033_FLED_CTRL5_MASK		0xC0
> +#define RT5033_FLED_CTRL5_RESV		0x10
> +#define RT5033_FLED_CTRL5_TA_GOOD	0x40
> +#define RT5033_FLED_CTRL5_TA_EXIST	0x80
> +
>   /* RT5033 control register */
>   #define RT5033_CTRL_FCCM_BUCK_MASK		0x00
>   #define RT5033_CTRL_BUCKOMS_MASK		0x01
> diff --git a/include/linux/mfd/rt5033.h b/include/linux/mfd/rt5033.h
> index 6cff5cf..6374d84 100644
> --- a/include/linux/mfd/rt5033.h
> +++ b/include/linux/mfd/rt5033.h
> @@ -12,10 +12,11 @@
>   #ifndef __RT5033_H__
>   #define __RT5033_H__
>
> -#include <linux/regulator/consumer.h>
>   #include <linux/i2c.h>
> -#include <linux/regmap.h>
> +#include <linux/led-class-flash.h>
>   #include <linux/power_supply.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>
>   /* RT5033 regulator IDs */
>   enum rt5033_regulators {
> @@ -59,4 +60,21 @@ struct rt5033_charger {
>   	struct rt5033_charger_data	*chg;
>   };
>
> +/* RT5033 Flash led platform data */
> +struct rt5033_led_config_data {
> +	u32 torch_max_microamp;
> +	u32 flash_max_microamp;
> +	u32 flash_max_timeout;
> +	enum led_brightness max_brightness;
> +};
> +
> +struct rt5033_led {
> +	struct device		*dev;
> +	struct rt5033_dev	*rt5033;
> +	struct regmap		*regmap;
> +
> +	struct led_classdev_flash fled_cdev;
> +	struct rt5033_led_config_data  *data;

It is not needed to have config data here.

> +};
> +
>   #endif /* __RT5033_H__ */
>


-- 
Best Regards,
Jacek Anaszewski