Date:   Tue, 22 May 2018 22:53:38 +0200
From:   Jacek Anaszewski <jacek.anaszewski@...il.com>
To:     Dan Murphy <dmurphy@...com>, robh+dt@...nel.org,
        mark.rutland@....com, andy.shevchenko@...il.com
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-leds@...r.kernel.org
Subject: Re: [PATCH v8 2/2] leds: lm3601x: Introduce the lm3601x LED driver

Hi Dan,

In three cases we should have "strobe" instead of "flash"
Please refer to the code below.

Otherwise it looks good to me - you even fixed some earlier
unnoticed issues.

On 05/22/2018 04:24 PM, Dan Murphy wrote:
> Introduce the family of LED devices that can
> drive a torch, strobe or IR LED.
> 
> The LED driver can be configured with a strobe
> timer to execute a strobe flash.  The IR LED
> brightness is controlled via the torch brightness
> register.
> 
> The data sheet for each the LM36010 and LM36011
> LED drivers can be found here:
> http://www.ti.com/product/LM36010
> http://www.ti.com/product/LM36011
> 
> Signed-off-by: Dan Murphy <dmurphy@...com>
> ---
> 
> v8 - Removed OF Kconfig dependency, change strobe to flash, updated label generation,
> fixed brightness calculation, added mutex_destroy and flash_unregister - https://patchwork.kernel.org/patch/10416163/
> 
> v7 - Numerous fixes to many to list.  Highlights are moved from OF APIs to device_property
> APIs, updated LED registration, timeout to reg algorithim, and fixed label generation -
> https://patchwork.kernel.org/patch/10401437/
> v6 - This driver has been heavily modified from v5.  There is no longer reading
> of individual child nodes.  There are too many changes to list here see -
> https://patchwork.kernel.org/patch/10392123/
> v5 - Fixed magic numbers, change reg cache type, added of_put_node to release
> the dt node ref, and I did not change the remove function to leave the LED in its
> state on driver removal - https://patchwork.kernel.org/patch/10391741/
> v4 - Fixed Cocci issue using ARRAY_SIZE - https://patchwork.kernel.org/patch/10389259/
> v3 - removed wildcard dt compatible, fixed copyright, fixed struct doc, removed
> RO registers from default, added regmap volatile for FLAGS_REG, updated regmap cache type,
> fixed unlock and extra semi colon in strobe_set, removed unnecessary out label
> in led register and fixed checking of the ret in brightness_set - https://patchwork.kernel.org/patch/10386243/
> v2 - Fixed kbuild issue and removed unused cdev_strobe - https://patchwork.kernel.org/patch/10384585/
> 
> 
>   drivers/leds/Kconfig        |   9 +
>   drivers/leds/Makefile       |   1 +
>   drivers/leds/leds-lm3601x.c | 492 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 502 insertions(+)
>   create mode 100644 drivers/leds/leds-lm3601x.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 2c896c0e69e1..d95d436e6089 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -145,6 +145,15 @@ config LEDS_LM3692X
>   	  This option enables support for the TI LM3692x family
>   	  of white LED string drivers used for backlighting.
>   
> +config LEDS_LM3601X
> +	tristate "LED support for LM3601x Chips"
> +	depends on LEDS_CLASS && I2C
> +	depends on LEDS_CLASS_FLASH
> +	select REGMAP_I2C
> +	help
> +	  This option enables support for the TI LM3601x family
> +	  of flash, torch and indicator classes.
> +
>   config LEDS_LOCOMO
>   	tristate "LED Support for Locomo device"
>   	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 91eca81cae82..b79807fe1b67 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -76,6 +76,7 @@ obj-$(CONFIG_LEDS_MLXREG)		+= leds-mlxreg.o
>   obj-$(CONFIG_LEDS_NIC78BX)		+= leds-nic78bx.o
>   obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
>   obj-$(CONFIG_LEDS_LM3692X)		+= leds-lm3692x.o
> +obj-$(CONFIG_LEDS_LM3601X)		+= leds-lm3601x.o
>   
>   # LED SPI Drivers
>   obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
> diff --git a/drivers/leds/leds-lm3601x.c b/drivers/leds/leds-lm3601x.c
> new file mode 100644
> index 000000000000..b1f0ede704c1
> --- /dev/null
> +++ b/drivers/leds/leds-lm3601x.c
> @@ -0,0 +1,492 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Flash and torch driver for Texas Instruments LM3601X LED
> +// Flash driver chip family
> +// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/led-class-flash.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <uapi/linux/uleds.h>
> +
> +#define LM3601X_LED_IR		0x0
> +#define LM3601X_LED_TORCH	0x1
> +
> +/* Registers */
> +#define LM3601X_ENABLE_REG	0x01
> +#define LM3601X_CFG_REG		0x02
> +#define LM3601X_LED_FLASH_REG	0x03
> +#define LM3601X_LED_TORCH_REG	0x04
> +#define LM3601X_FLAGS_REG	0x05
> +#define LM3601X_DEV_ID_REG	0x06
> +
> +#define LM3601X_SW_RESET	BIT(7)
> +
> +/* Enable Mode bits */
> +#define LM3601X_MODE_STANDBY	0x00
> +#define LM3601X_MODE_IR_DRV	BIT(0)
> +#define LM3601X_MODE_TORCH	BIT(1)
> +#define LM3601X_MODE_STROBE	(BIT(0) | BIT(1))
> +#define LM3601X_STRB_EN		BIT(2)
> +#define LM3601X_STRB_EDGE_TRIG	BIT(3)
> +#define LM3601X_IVFM_EN		BIT(4)
> +
> +#define LM36010_BOOST_LIMIT_28	BIT(5)
> +#define LM36010_BOOST_FREQ_4MHZ	BIT(6)
> +#define LM36010_BOOST_MODE_PASS	BIT(7)
> +
> +/* Flag Mask */
> +#define LM3601X_FLASH_TIME_OUT	BIT(0)
> +#define LM3601X_UVLO_FAULT	BIT(1)
> +#define LM3601X_THERM_SHUTDOWN	BIT(2)
> +#define LM3601X_THERM_CURR	BIT(3)
> +#define LM36010_CURR_LIMIT	BIT(4)
> +#define LM3601X_SHORT_FAULT	BIT(5)
> +#define LM3601X_IVFM_TRIP	BIT(6)
> +#define LM36010_OVP_FAULT	BIT(7)
> +
> +#define LM3601X_MAX_TORCH_I_UA	376000
> +#define LM3601X_MIN_TORCH_I_UA	2400
> +#define LM3601X_TORCH_REG_DIV	2965
> +
> +#define LM3601X_MAX_STROBE_I_UA	1500000
> +#define LM3601X_MIN_STROBE_I_UA	11000
> +#define LM3601X_STROBE_REG_DIV	11800
> +
> +#define LM3601X_TIMEOUT_MASK	0x1e
> +#define LM3601X_ENABLE_MASK	(LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)
> +
> +#define LM3601X_LOWER_STEP_US	40000
> +#define LM3601X_UPPER_STEP_US	200000
> +#define LM3601X_MIN_TIMEOUT_US	40000
> +#define LM3601X_MAX_TIMEOUT_US	1600000
> +#define LM3601X_TIMEOUT_XOVER_US 400000
> +
> +enum lm3601x_type {
> +	CHIP_LM36010 = 0,
> +	CHIP_LM36011,
> +};
> +
> +/**
> + * struct lm3601x_led -
> + * @fled_cdev: flash LED class device pointer
> + * @client: Pointer to the I2C client
> + * @regmap: Devices register map
> + * @lock: Lock for reading/writing the device
> + * @led_name: LED label for the Torch or IR LED
> + * @flash_timeout: the timeout for the flash
> + * @last_flag: last known flags register value
> + * @torch_current_max: maximum current for the torch
> + * @flash_current_max: maximum current for the flash
> + * @max_flash_timeout: maximum timeout for the flash
> + * @led_mode: The mode to enable either IR or Torch
> + */
> +struct lm3601x_led {
> +	struct led_classdev_flash fled_cdev;
> +	struct i2c_client *client;
> +	struct regmap *regmap;
> +	struct mutex lock;
> +
> +	char led_name[LED_MAX_NAME_SIZE];
> +
> +	unsigned int flash_timeout;
> +	unsigned int last_flag;
> +
> +	u32 torch_current_max;
> +	u32 flash_current_max;
> +	u32 max_flash_timeout;
> +
> +	u32 led_mode;
> +};
> +
> +static const struct reg_default lm3601x_regmap_defs[] = {
> +	{ LM3601X_ENABLE_REG, 0x20 },
> +	{ LM3601X_CFG_REG, 0x15 },
> +	{ LM3601X_LED_FLASH_REG, 0x00 },
> +	{ LM3601X_LED_TORCH_REG, 0x00 },
> +};
> +
> +static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	switch (reg) {
> +	case LM3601X_FLAGS_REG:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct regmap_config lm3601x_regmap = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = LM3601X_DEV_ID_REG,
> +	.reg_defaults = lm3601x_regmap_defs,
> +	.num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
> +	.cache_type = REGCACHE_RBTREE,
> +	.volatile_reg = lm3601x_volatile_reg,
> +};
> +
> +static struct lm3601x_led *fled_cdev_to_led(
> +				struct led_classdev_flash *fled_cdev)
> +{
> +	return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
> +}
> +
> +static int lm3601x_read_faults(struct lm3601x_led *led)
> +{
> +	int flags_val;
> +	int ret;
> +
> +	ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
> +	if (ret < 0)
> +		return -EIO;
> +
> +	led->last_flag = 0;
> +
> +	if (flags_val & LM36010_OVP_FAULT)
> +		led->last_flag |= LED_FAULT_OVER_VOLTAGE;
> +
> +	if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
> +		led->last_flag |= LED_FAULT_OVER_TEMPERATURE;
> +
> +	if (flags_val & LM3601X_SHORT_FAULT)
> +		led->last_flag |= LED_FAULT_SHORT_CIRCUIT;
> +
> +	if (flags_val & LM36010_CURR_LIMIT)
> +		led->last_flag |= LED_FAULT_OVER_CURRENT;
> +
> +	if (flags_val & LM3601X_UVLO_FAULT)
> +		led->last_flag |= LED_FAULT_UNDER_VOLTAGE;
> +
> +	if (flags_val & LM3601X_IVFM_TRIP)
> +		led->last_flag |= LED_FAULT_INPUT_VOLTAGE;
> +
> +	if (flags_val & LM3601X_THERM_SHUTDOWN)
> +		led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;
> +
> +	return led->last_flag;
> +}
> +
> +static int lm3601x_brightness_set(struct led_classdev *cdev,
> +					enum led_brightness brightness)
> +{
> +	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +	int ret, led_mode_val;
> +
> +	mutex_lock(&led->lock);
> +
> +	ret = lm3601x_read_faults(led);
> +	if (ret < 0)
> +		goto out;
> +
> +	if (led->led_mode == LM3601X_LED_TORCH)
> +		led_mode_val = LM3601X_MODE_TORCH;
> +	else
> +		led_mode_val = LM3601X_MODE_IR_DRV;
> +
> +	if (brightness == LED_OFF) {
> +		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +					led_mode_val, LED_OFF);
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +				LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
> +				led_mode_val);
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3601x_flash_set(struct led_classdev_flash *fled_cdev,
> +				bool state)
> +{
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +	int timeout_reg_val = 0;
> +	int current_timeout;
> +	int ret;
> +
> +	mutex_lock(&led->lock);
> +
> +	ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
> +	if (ret < 0)
> +		goto out;
> +
> +	if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
> +		timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
> +	else
> +		timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;
> +
> +	if (led->flash_timeout != current_timeout)
> +		ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
> +					LM3601X_TIMEOUT_MASK, timeout_reg_val);
> +
> +	if (state)
> +		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +					LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
> +					LM3601X_MODE_STROBE);
> +	else
> +		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +					LM3601X_MODE_STROBE, LED_OFF);
> +
> +	ret = lm3601x_read_faults(led);
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
> +					u32 brightness)
> +{
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +	int ret;
> +	u8 brightness_val;
> +
> +	mutex_lock(&led->lock);
> +	ret = lm3601x_read_faults(led);
> +	if (ret < 0)
> +		goto out;
> +
> +	if (brightness == LED_OFF) {
> +		ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +					LM3601X_MODE_STROBE, LED_OFF);
> +		goto out;
> +	}
> +
> +	brightness_val = brightness / LM3601X_STROBE_REG_DIV;
> +
> +	ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
> +				u32 timeout)
> +{
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +	int ret = 0;
> +
> +	mutex_lock(&led->lock);
> +
> +	led->flash_timeout = timeout;
> +
> +	mutex_unlock(&led->lock);
> +
> +	return ret;
> +}
> +
> +static int lm3601x_flash_get(struct led_classdev_flash *fled_cdev,
> +				bool *state)
> +{
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +	int ret;
> +	int flash_state;

s/flash_state/strobe_state/

> +
> +	mutex_lock(&led->lock);
> +
> +	ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &flash_state);
> +	if (ret < 0)
> +		goto out;
> +
> +	*state = flash_state & LM3601X_MODE_STROBE;
> +
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
> +				u32 *fault)
> +{
> +	struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
> +
> +	lm3601x_read_faults(led);
> +
> +	*fault = led->last_flag;
> +
> +	return 0;
> +}
> +
> +static const struct led_flash_ops flash_ops = {
> +	.flash_brightness_set	= lm3601x_flash_brightness_set,
> +	.strobe_set		= lm3601x_flash_set,
> +	.strobe_get		= lm3601x_flash_get,

In case of the above two functions let's stay by "strobe".

I.e.: lm3601x_strobe_set and lm3601x_strobe_get.

> +	.timeout_set		= lm3601x_flash_timeout_set,
> +	.fault_get		= lm3601x_flash_fault_get,
> +};
> +
> +static int lm3601x_register_leds(struct lm3601x_led *led)
> +{
> +	struct led_classdev *led_cdev;
> +	struct led_flash_setting *setting;
> +
> +	led->fled_cdev.ops = &flash_ops;
> +
> +	setting = &led->fled_cdev.timeout;
> +	setting->min = LM3601X_MIN_TIMEOUT_US;
> +	setting->max = led->max_flash_timeout;
> +	setting->step = LM3601X_LOWER_STEP_US;
> +	setting->val = led->max_flash_timeout;
> +
> +	setting = &led->fled_cdev.brightness;
> +	setting->min = LM3601X_MIN_STROBE_I_UA;
> +	setting->max = led->flash_current_max;
> +	setting->step = LM3601X_TORCH_REG_DIV;
> +	setting->val = led->flash_current_max;
> +
> +	led_cdev = &led->fled_cdev.led_cdev;
> +	led_cdev->name = led->led_name;
> +	led_cdev->brightness_set_blocking = lm3601x_brightness_set;
> +	led_cdev->max_brightness = DIV_ROUND_UP(led->torch_current_max,
> +						LM3601X_TORCH_REG_DIV);
> +	led_cdev->flags |= LED_DEV_CAP_FLASH;
> +
> +	return led_classdev_flash_register(&led->client->dev, &led->fled_cdev);
> +}
> +
> +static int lm3601x_parse_node(struct lm3601x_led *led,
> +			      struct device_node *node)
> +{
> +	struct fwnode_handle *child = NULL;
> +	int ret = -ENODEV;
> +	const char *name;
> +
> +	child = device_get_next_child_node(&led->client->dev, child);
> +	if (!child) {
> +		dev_err(&led->client->dev, "No LED Child node\n");
> +		return ret;
> +	}
> +
> +	ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
> +	if (ret) {
> +		dev_err(&led->client->dev, "reg DT property missing\n");
> +		goto out_err;
> +	}
> +
> +	if (led->led_mode > LM3601X_LED_TORCH ||
> +	    led->led_mode < LM3601X_LED_IR) {
> +		dev_warn(&led->client->dev, "Invalid led mode requested\n");
> +		ret = -EINVAL;
> +		goto out_err;
> +	}
> +
> +	ret = fwnode_property_read_string(child, "label", &name);
> +	if (ret) {
> +		if (led->led_mode == LM3601X_LED_TORCH)
> +			name = "torch";
> +		else
> +			name = "infrared";
> +	}
> +
> +	snprintf(led->led_name, sizeof(led->led_name),
> +		"%s:%s", led->client->name, name);
> +
> +	ret = fwnode_property_read_u32(child, "led-max-microamp",
> +					&led->torch_current_max);
> +	if (ret < 0) {
> +		dev_warn(&led->client->dev,
> +			"led-max-microamp DT property missing\n");
> +		goto out_err;
> +	}
> +
> +	ret = fwnode_property_read_u32(child, "flash-max-microamp",
> +				&led->flash_current_max);
> +	if (ret < 0) {
> +		dev_warn(&led->client->dev,
> +			 "flash-max-microamp DT property missing\n");
> +		goto out_err;
> +	}
> +
> +	ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
> +				&led->max_flash_timeout);
> +	if (ret < 0) {
> +		dev_warn(&led->client->dev,
> +			 "flash-max-timeout-us DT property missing\n");
> +		goto out_err;
> +	}
> +
> +out_err:
> +	fwnode_handle_put(child);
> +	return ret;
> +}
> +
> +static int lm3601x_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct lm3601x_led *led;
> +	int err;
> +
> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	led->client = client;
> +	i2c_set_clientdata(client, led);
> +
> +	err = lm3601x_parse_node(led, client->dev.of_node);
> +	if (err < 0)
> +		return -ENODEV;
> +
> +	led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
> +	if (IS_ERR(led->regmap)) {
> +		err = PTR_ERR(led->regmap);
> +		dev_err(&client->dev,
> +			"Failed to allocate register map: %d\n", err);
> +		return err;
> +	}
> +
> +	mutex_init(&led->lock);
> +
> +	return lm3601x_register_leds(led);
> +}
> +
> +static int lm3601x_remove(struct i2c_client *client)
> +{
> +	struct lm3601x_led *led = i2c_get_clientdata(client);
> +
> +	led_classdev_flash_unregister(&led->fled_cdev);
> +	mutex_destroy(&led->lock);
> +
> +	return regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
> +			   LM3601X_ENABLE_MASK,
> +			   LM3601X_MODE_STANDBY);
> +}
> +
> +static const struct i2c_device_id lm3601x_id[] = {
> +	{ "LM36010", CHIP_LM36010 },
> +	{ "LM36011", CHIP_LM36011 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, lm3601x_id);
> +
> +static const struct of_device_id of_lm3601x_leds_match[] = {
> +	{ .compatible = "ti,lm36010", },
> +	{ .compatible = "ti,lm36011", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);
> +
> +static struct i2c_driver lm3601x_i2c_driver = {
> +	.driver = {
> +		.name = "lm3601x",
> +		.of_match_table = of_lm3601x_leds_match,
> +	},
> +	.probe = lm3601x_probe,
> +	.remove = lm3601x_remove,
> +	.id_table = lm3601x_id,
> +};
> +module_i2c_driver(lm3601x_i2c_driver);
> +
> +MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
> +MODULE_AUTHOR("Dan Murphy <dmurphy@...com>");
> +MODULE_LICENSE("GPL v2");
> 

-- 
Best regards,
Jacek Anaszewski

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