[1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver

Message ID 20171113205052.25884-1-dmurphy@ti.com
State Superseded
Headers show
Series
  • [1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver
Related show

Commit Message

Dan Murphy Nov. 13, 2017, 8:50 p.m.
This adds the devicetree bindings for the LM3692x
I2C LED string driver.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---
 .../devicetree/bindings/leds/leds-lm3692x.txt      | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-lm3692x.txt

Comments

Pavel Machek Nov. 15, 2017, 10:35 a.m. | #1
On Mon 2017-11-13 14:50:51, Dan Murphy wrote:
> This adds the devicetree bindings for the LM3692x
> I2C LED string driver.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

> diff --git a/Documentation/devicetree/bindings/leds/leds-lm3692x.txt b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
> new file mode 100644
> index 000000000000..cfef67bd4100
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
> @@ -0,0 +1,28 @@
> +* Texas Instruments - LM3692x Highly Efficient Dual-String White LED Driver
> +
> +The LM36922 is an ultra-compact, highly efficient,
> +two string white-LED driver designed for LCD display
> +backlighting.
> +
> +Required properties:
> +	- compatible:
> +		"ti,lm3692x"
> +	- reg -  I2C slave address
> +
> +Optional properties:
> +	- label - Used for naming LEDs
> +	- enable-gpio - gpio pin to enable/disable the device.
> +	- supply - "vled" - LED supply
> +
> +Example:
> +
> +leds: leds@6 {
> +	compatible = "ti,lm3692x";
> +	reg = <0x36>;
> +	label = "backlight_cluster";
> +	enable-gpio = <&gpio1 28 GPIO_ACTIVE_HIGH>;
> +	vled-supply = <&vbatt>;
> +}
> +
> +For more product information please see the link below:
> +http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
Pavel Machek Nov. 15, 2017, 10:45 a.m. | #2
On Mon 2017-11-13 14:50:52, Dan Murphy wrote:
> Introducing the LM3692x Dual-String white LED driver.
> 
> Data sheet is located
> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
>  drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 380 insertions(+)
>  create mode 100644 drivers/leds/leds-lm3692x.c
> 
> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
> new file mode 100644
> index 000000000000..beb753abc7b0
> --- /dev/null
> +++ b/drivers/leds/leds-lm3692x.c
> @@ -0,0 +1,380 @@
> +/*
> + * TI lm3692x LED Driver
> + *
> + * Copyright (C) 2017 Texas Instruments
> + *
> + * Author: Dan Murphy <dmurphy@ti.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.
> + *
> + */

I'd put data sheet link here.

> +/**
> + * struct lm3692x_led -
> + * @lock - Lock for reading/writing the device
> + * @client - Pointer to the I2C client
> + * @led_dev - led class device pointer
> + * @regmap - Devices register map
> + * @enable_gpio - VDDIO/EN gpio to enable communication interface
> + * @regulator - LED supply regulator pointer
> + * @label - LED label
> + **/

Are you sure this is linuxdoc? Would */ at the end be enough?

> +static int lm3692x_fault_check(struct lm3692x_led *led)
> +{
> +	int ret, fault;
> +	unsigned int read_buf;
> +
> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
> +	if (ret)
> +		goto out;

Just return here.

> +	/*
> +	 * For glitch free operation, the following data should
> +	 * only be written while device enable bit is 0
> +	 * Per Section 7.5.14 of the data sheet
> +	 */

"per section 7.5.14 of the data sheet."

> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
> +			LM3692X_BRHT_MODE_RAMP_MULTI |
> +			LM3692X_BL_ADJ_POL |
> +			LM3692X_RAMP_RATE_250us);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");

If something fails, is it wise to continue?

Thanks,
									Pavel
Dan Murphy Nov. 15, 2017, 12:47 p.m. | #3
Pavel

Thanks

On 11/15/2017 04:45 AM, Pavel Machek wrote:
> On Mon 2017-11-13 14:50:52, Dan Murphy wrote:
>> Introducing the LM3692x Dual-String white LED driver.
>>
>> Data sheet is located
>> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>  drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 380 insertions(+)
>>  create mode 100644 drivers/leds/leds-lm3692x.c
>>
>> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
>> new file mode 100644
>> index 000000000000..beb753abc7b0
>> --- /dev/null
>> +++ b/drivers/leds/leds-lm3692x.c
>> @@ -0,0 +1,380 @@
>> +/*
>> + * TI lm3692x LED Driver
>> + *
>> + * Copyright (C) 2017 Texas Instruments
>> + *
>> + * Author: Dan Murphy <dmurphy@ti.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.
>> + *
>> + */
> 
> I'd put data sheet link here.

OK

> 
>> +/**
>> + * struct lm3692x_led -
>> + * @lock - Lock for reading/writing the device
>> + * @client - Pointer to the I2C client
>> + * @led_dev - led class device pointer
>> + * @regmap - Devices register map
>> + * @enable_gpio - VDDIO/EN gpio to enable communication interface
>> + * @regulator - LED supply regulator pointer
>> + * @label - LED label
>> + **/
> 
> Are you sure this is linuxdoc? Would */ at the end be enough?

I will fix this

> 
>> +static int lm3692x_fault_check(struct lm3692x_led *led)
>> +{
>> +	int ret, fault;
>> +	unsigned int read_buf;
>> +
>> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
>> +	if (ret)
>> +		goto out;
> 
> Just return here.

OK

> 
>> +	/*
>> +	 * For glitch free operation, the following data should
>> +	 * only be written while device enable bit is 0
>> +	 * Per Section 7.5.14 of the data sheet
>> +	 */
> 
> "per section 7.5.14 of the data sheet."

OK

> 
>> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
>> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
>> +	if (ret)
>> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
>> +
>> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
>> +			LM3692X_BRHT_MODE_RAMP_MULTI |
>> +			LM3692X_BL_ADJ_POL |
>> +			LM3692X_RAMP_RATE_250us);
>> +	if (ret)
>> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
>> +
>> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
>> +	if (ret)
>> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
> 
> If something fails, is it wise to continue?
> 
> Thanks,
> 									Pavel
>
Pavel Machek Nov. 15, 2017, 1 p.m. | #4
Hi!

> >> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
> >> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
> >> +	if (ret)
> >> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
> >> +
> >> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
> >> +			LM3692X_BRHT_MODE_RAMP_MULTI |
> >> +			LM3692X_BL_ADJ_POL |
> >> +			LM3692X_RAMP_RATE_250us);
> >> +	if (ret)
> >> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
> >> +
> >> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
> >> +	if (ret)
> >> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
> > 
> > If something fails, is it wise to continue?

If something fails, is it wise to continue?

									Pavel
Dan Murphy Nov. 15, 2017, 1:06 p.m. | #5
Pavel

On 11/15/2017 07:00 AM, Pavel Machek wrote:
> Hi!
> 
>>>> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
>>>> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
>>>> +	if (ret)
>>>> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
>>>> +
>>>> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
>>>> +			LM3692X_BRHT_MODE_RAMP_MULTI |
>>>> +			LM3692X_BL_ADJ_POL |
>>>> +			LM3692X_RAMP_RATE_250us);
>>>> +	if (ret)
>>>> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
>>>> +
>>>> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
>>>> +	if (ret)
>>>> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
>>>
>>> If something fails, is it wise to continue?
> 
> If something fails, is it wise to continue?
> 

Sorry missed that comment.  It is ok to continue but probably should goto out and return
an error so the probe fails.

Dan

> 									Pavel
>
Dan Murphy Nov. 15, 2017, 1:11 p.m. | #6
On 11/13/2017 02:50 PM, Dan Murphy wrote:
> Introducing the LM3692x Dual-String white LED driver.
> 
> Data sheet is located
> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
>  drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 380 insertions(+)
>  create mode 100644 drivers/leds/leds-lm3692x.c
> 
> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
> new file mode 100644
> index 000000000000..beb753abc7b0
> --- /dev/null
> +++ b/drivers/leds/leds-lm3692x.c
> @@ -0,0 +1,380 @@
> +/*
> + * TI lm3692x LED Driver
> + *
> + * Copyright (C) 2017 Texas Instruments
> + *
> + * Author: Dan Murphy <dmurphy@ti.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/i2c.h>
> +#include <linux/init.h>
> +#include <linux/leds.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/slab.h>
> +
> +#define LM3692X_LED_NAME	"lm3692x_led"
> +
> +#define LM3692X_REV		0x0
> +#define LM3692X_RESET		0x1
> +#define LM3692X_EN		0x10
> +#define LM3692X_BRT_CTRL	0x11
> +#define LM3692X_PWM_CTRL	0x12
> +#define LM3692X_BOOST_CTRL	0x13
> +#define LM3692X_AUTO_FREQ_HI	0x15
> +#define LM3692X_AUTO_FREQ_LO	0x16
> +#define LM3692X_BL_ADJ_THRESH	0x17
> +#define LM3692X_BRT_LSB		0x18
> +#define LM3692X_BRT_MSB		0x19
> +#define LM3692X_FAULT_CTRL	0x1e
> +#define LM3692X_FAULT_FLAGS	0x1f
> +
> +#define LM3692X_SW_RESET	BIT(0)
> +#define LM3692X_DEVICE_EN	BIT(0)
> +#define LM3692X_LED1_EN		BIT(1)
> +#define LM3692X_LED2_EN		BIT(2)
> +
> +/* Brightness Control Bits */
> +#define LM3692X_BL_ADJ_POL	BIT(0)
> +#define LM3692X_RAMP_RATE_125us	0x00
> +#define LM3692X_RAMP_RATE_250us	BIT(1)
> +#define LM3692X_RAMP_RATE_500us BIT(2)
> +#define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
> +#define LM3692X_RAMP_RATE_2ms	BIT(3)
> +#define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
> +#define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
> +#define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))
> +#define LM3692X_RAMP_EN		BIT(4)
> +#define LM3692X_BRHT_MODE_REG	0x00
> +#define LM3692X_BRHT_MODE_PWM	BIT(5)
> +#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
> +#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
> +#define LM3692X_MAP_MODE_EXP	BIT(7)
> +
> +/* PWM Register Bits */
> +#define LM3692X_PWM_FILTER_100	BIT(0)
> +#define LM3692X_PWM_FILTER_150	BIT(1)
> +#define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
> +#define LM3692X_PWM_HYSTER_1LSB BIT(2)
> +#define LM3692X_PWM_HYSTER_2LSB	BIT(3)
> +#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
> +#define LM3692X_PWM_HYSTER_4LSB BIT(4)
> +#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
> +#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
> +#define LM3692X_PWM_POLARITY	BIT(5)
> +#define LM3692X_PWM_SAMP_4MHZ	BIT(6)
> +#define LM3692X_PWM_SAMP_24MHZ	BIT(7)
> +
> +/* Boost Control Bits */
> +#define LM3692X_OCP_PROT_1A	BIT(0)
> +#define LM3692X_OCP_PROT_1_25A	BIT(1)
> +#define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
> +#define LM3692X_OVP_21V		BIT(2)
> +#define LM3692X_OVP_25V		BIT(3)
> +#define LM3692X_OVP_29V		(BIT(2) | BIT(3))
> +#define LM3692X_MIN_IND_22UH	BIT(4)
> +#define LM3692X_BOOST_SW_1MHZ	BIT(5)
> +#define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)
> +
> +/* Fault Control Bits */
> +#define LM3692X_FAULT_CTRL_OVP BIT(0)
> +#define LM3692X_FAULT_CTRL_OCP BIT(1)
> +#define LM3692X_FAULT_CTRL_TSD BIT(2)
> +#define LM3692X_FAULT_CTRL_OPEN BIT(3)
> +
> +/* Fault Flag Bits */
> +#define LM3692X_FAULT_FLAG_OVP BIT(0)
> +#define LM3692X_FAULT_FLAG_OCP BIT(1)
> +#define LM3692X_FAULT_FLAG_TSD BIT(2)
> +#define LM3692X_FAULT_FLAG_SHRT BIT(3)
> +#define LM3692X_FAULT_FLAG_OPEN BIT(4)
> +
> +/**
> + * struct lm3692x_led -
> + * @lock - Lock for reading/writing the device
> + * @client - Pointer to the I2C client
> + * @led_dev - led class device pointer
> + * @regmap - Devices register map
> + * @enable_gpio - VDDIO/EN gpio to enable communication interface
> + * @regulator - LED supply regulator pointer
> + * @label - LED label
> + **/
> +struct lm3692x_led {
> +	struct mutex lock;
> +	struct i2c_client *client;
> +	struct led_classdev led_dev;
> +	struct regmap *regmap;
> +	struct gpio_desc *enable_gpio;
> +	struct regulator *regulator;
> +	const char *label;
> +};
> +
> +static const struct reg_default lm3692x_reg_defs[] = {
> +	{LM3692X_EN, 0xf},
> +	{LM3692X_BRT_CTRL, 0x61},
> +	{LM3692X_PWM_CTRL, 0x73},
> +	{LM3692X_BOOST_CTRL, 0x6f},
> +	{LM3692X_AUTO_FREQ_HI, 0x0},
> +	{LM3692X_AUTO_FREQ_LO, 0x0},
> +	{LM3692X_BL_ADJ_THRESH, 0x0},
> +	{LM3692X_BRT_LSB, 0x7},
> +	{LM3692X_BRT_MSB, 0xff},
> +	{LM3692X_FAULT_CTRL, 0x7},
> +};
> +
> +static const struct regmap_config lm3692x_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = LM3692X_FAULT_FLAGS,
> +	.reg_defaults = lm3692x_reg_defs,
> +	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
> +	.cache_type = REGCACHE_RBTREE,
> +};
> +
> +static int lm3692x_fault_check(struct lm3692x_led *led)
> +{
> +	int ret, fault;
> +	unsigned int read_buf;
> +
> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
> +	if (ret)
> +		goto out;
> +
> +	fault = read_buf;
> +
> +	if (fault)
> +		dev_err(&led->client->dev, "Detected a fault 0x%X\n",
> +			fault);
> +out:
> +	return ret;
> +}
> +
> +static int lm3692x_brightness_set(struct led_classdev *led_cdev,
> +				enum led_brightness brt_val)
> +{
> +	struct lm3692x_led *led =
> +			container_of(led_cdev, struct lm3692x_led, led_dev);
> +	int led_brightness = (brt_val << 4) + 7;

After a peer review with the hardware team it was determined that the brightness value
calculation always sets the LSB to a value of 7.  Therefore this will be changed in patch
v2 so that the MSB will contain the brt_val and the LSB will contain the 3 MSB bits of the
brt_val.

So the values will look something like this:

Code 0x00 thru code 0x1f --> LSB = 0 
Code 0x20 thru code 0x3f --> LSB = 1, 0x101 up to 0x1f9
Code 0x40 thru code 0x5f --> LSB = 2, 0x202 up to 0x2fa
Code 0x60 thru code 0x7f --> LSB = 3, 0x303 thru 0x3fb
Code 0x80 thru code 0x9f --> LSB = 4, 0x404 thru 0x4fc
.
.
Code 0xe0 thru code 0xff --> LSB = 7, 0x707 thru 0x7ff

> +	int ret;
> +
> +	if (brt_val == LED_OFF)
> +		led_brightness = 0;
> +
> +	mutex_lock(&led->lock);
> +
> +	ret = lm3692x_fault_check(led);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_MSB,
> +			(led_brightness & 0xff0) >> 4);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot write MSB\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_LSB,
> +			led_brightness & 0x07);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot write LSB\n");
> +		goto out;
> +	}
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3692x_init(struct lm3692x_led *led)
> +{
> +	int ret;
> +
> +	if (led->regulator) {
> +		ret = regulator_enable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to enable regulator\n");
> +	}
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 1);
> +
> +	ret = lm3692x_fault_check(led);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Fail writing BRT CTRL\n");
> +	/*
> +	 * For glitch free operation, the following data should
> +	 * only be written while device enable bit is 0
> +	 * Per Section 7.5.14 of the data sheet
> +	 */
> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
> +			LM3692X_BRHT_MODE_RAMP_MULTI |
> +			LM3692X_BL_ADJ_POL |
> +			LM3692X_RAMP_RATE_250us);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming AUTO LO FREQ\n");
> +
> +
> +	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BL Threshold\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
> +			LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BRT CTRL\n");
> +
> +	return ret;
> +out:
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 0);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to disable regulator\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int lm3692x_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	int ret;
> +	struct lm3692x_led *led;
> +	struct device_node *np = client->dev.of_node;
> +
> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	if (client->dev.of_node) {
> +		ret = of_property_read_string(np, "label", &led->label);
> +		if (ret)
> +			led->label = LM3692X_LED_NAME;
> +	}
> +
> +	led->enable_gpio = devm_gpiod_get_optional(&client->dev,
> +						   "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(led->enable_gpio)) {
> +		ret = PTR_ERR(led->enable_gpio);
> +		dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->regulator = devm_regulator_get(&client->dev, "vled");
> +	if (IS_ERR(led->regulator))
> +		led->regulator = NULL;
> +
> +	led->client = client;
> +	led->led_dev.name = led->label;
> +	led->led_dev.max_brightness = LED_FULL;
> +	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
> +
> +	mutex_init(&led->lock);
> +
> +	i2c_set_clientdata(client, led);
> +
> +	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
> +	if (IS_ERR(led->regmap)) {
> +		ret = PTR_ERR(led->regmap);
> +		dev_err(&client->dev, "Failed to allocate register map: %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = lm3692x_init(led);
> +	if (ret)
> +		return ret;
> +
> +	ret = led_classdev_register(&client->dev, &led->led_dev);
> +	if (ret) {
> +		dev_err(&client->dev, "led register err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lm3692x_remove(struct i2c_client *client)
> +{
> +	struct lm3692x_led *led = i2c_get_clientdata(client);
> +	int ret;
> +
> +	led_classdev_unregister(&led->led_dev);
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 0);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to disable regulator\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id lm3692x_id[] = {
> +	{ "lm3692x", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, lm3692x_id);
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id of_lm3692x_leds_match[] = {
> +	{ .compatible = "ti,lm3692x", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
> +#endif
> +
> +static struct i2c_driver lm3692x_driver = {
> +	.driver = {
> +		.name	= "lm3692x",
> +		.of_match_table = of_match_ptr(of_lm3692x_leds_match),
> +	},
> +	.probe		= lm3692x_probe,
> +	.remove		= lm3692x_remove,
> +	.id_table	= lm3692x_id,
> +};
> +module_i2c_driver(lm3692x_driver);
> +
> +MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
> +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
> +MODULE_LICENSE("GPL");
>
Andrew F. Davis Nov. 16, 2017, 3:48 a.m. | #7
On 11/13/2017 02:50 PM, Dan Murphy wrote:
> Introducing the LM3692x Dual-String white LED driver.
> 
> Data sheet is located
> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---

Looks like v3 is posted but I can't find it in my mailbox :/ but the
comments below should still be valid.

>  drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 380 insertions(+)
>  create mode 100644 drivers/leds/leds-lm3692x.c
> 
> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
> new file mode 100644
> index 000000000000..beb753abc7b0
> --- /dev/null
> +++ b/drivers/leds/leds-lm3692x.c
> @@ -0,0 +1,380 @@
> +/*
> + * TI lm3692x LED Driver
> + *
> + * Copyright (C) 2017 Texas Instruments
> + *
> + * Author: Dan Murphy <dmurphy@ti.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/i2c.h>
> +#include <linux/init.h>
> +#include <linux/leds.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/slab.h>
> +
> +#define LM3692X_LED_NAME	"lm3692x_led"
> +
> +#define LM3692X_REV		0x0
> +#define LM3692X_RESET		0x1
> +#define LM3692X_EN		0x10
> +#define LM3692X_BRT_CTRL	0x11
> +#define LM3692X_PWM_CTRL	0x12
> +#define LM3692X_BOOST_CTRL	0x13
> +#define LM3692X_AUTO_FREQ_HI	0x15
> +#define LM3692X_AUTO_FREQ_LO	0x16
> +#define LM3692X_BL_ADJ_THRESH	0x17
> +#define LM3692X_BRT_LSB		0x18
> +#define LM3692X_BRT_MSB		0x19
> +#define LM3692X_FAULT_CTRL	0x1e
> +#define LM3692X_FAULT_FLAGS	0x1f
> +
> +#define LM3692X_SW_RESET	BIT(0)
> +#define LM3692X_DEVICE_EN	BIT(0)
> +#define LM3692X_LED1_EN		BIT(1)
> +#define LM3692X_LED2_EN		BIT(2)
> +
> +/* Brightness Control Bits */
> +#define LM3692X_BL_ADJ_POL	BIT(0)
> +#define LM3692X_RAMP_RATE_125us	0x00
> +#define LM3692X_RAMP_RATE_250us	BIT(1)
> +#define LM3692X_RAMP_RATE_500us BIT(2)
> +#define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
> +#define LM3692X_RAMP_RATE_2ms	BIT(3)
> +#define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
> +#define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
> +#define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))

The above look like you are just counting in binary, I'd just list the
numbers then shift them by one.

> +#define LM3692X_RAMP_EN		BIT(4)
> +#define LM3692X_BRHT_MODE_REG	0x00
> +#define LM3692X_BRHT_MODE_PWM	BIT(5)
> +#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
> +#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
> +#define LM3692X_MAP_MODE_EXP	BIT(7)
> +
> +/* PWM Register Bits */
> +#define LM3692X_PWM_FILTER_100	BIT(0)
> +#define LM3692X_PWM_FILTER_150	BIT(1)
> +#define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
> +#define LM3692X_PWM_HYSTER_1LSB BIT(2)
> +#define LM3692X_PWM_HYSTER_2LSB	BIT(3)
> +#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
> +#define LM3692X_PWM_HYSTER_4LSB BIT(4)
> +#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
> +#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))

Same here, looks like a couple below too.

> +#define LM3692X_PWM_POLARITY	BIT(5)
> +#define LM3692X_PWM_SAMP_4MHZ	BIT(6)
> +#define LM3692X_PWM_SAMP_24MHZ	BIT(7)
> +
> +/* Boost Control Bits */
> +#define LM3692X_OCP_PROT_1A	BIT(0)
> +#define LM3692X_OCP_PROT_1_25A	BIT(1)
> +#define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
> +#define LM3692X_OVP_21V		BIT(2)
> +#define LM3692X_OVP_25V		BIT(3)
> +#define LM3692X_OVP_29V		(BIT(2) | BIT(3))
> +#define LM3692X_MIN_IND_22UH	BIT(4)
> +#define LM3692X_BOOST_SW_1MHZ	BIT(5)
> +#define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)
> +
> +/* Fault Control Bits */
> +#define LM3692X_FAULT_CTRL_OVP BIT(0)
> +#define LM3692X_FAULT_CTRL_OCP BIT(1)
> +#define LM3692X_FAULT_CTRL_TSD BIT(2)
> +#define LM3692X_FAULT_CTRL_OPEN BIT(3)
> +
> +/* Fault Flag Bits */
> +#define LM3692X_FAULT_FLAG_OVP BIT(0)
> +#define LM3692X_FAULT_FLAG_OCP BIT(1)
> +#define LM3692X_FAULT_FLAG_TSD BIT(2)
> +#define LM3692X_FAULT_FLAG_SHRT BIT(3)
> +#define LM3692X_FAULT_FLAG_OPEN BIT(4)
> +
> +/**
> + * struct lm3692x_led -
> + * @lock - Lock for reading/writing the device
> + * @client - Pointer to the I2C client
> + * @led_dev - led class device pointer
> + * @regmap - Devices register map
> + * @enable_gpio - VDDIO/EN gpio to enable communication interface
> + * @regulator - LED supply regulator pointer
> + * @label - LED label
> + **/
> +struct lm3692x_led {
> +	struct mutex lock;
> +	struct i2c_client *client;
> +	struct led_classdev led_dev;
> +	struct regmap *regmap;
> +	struct gpio_desc *enable_gpio;
> +	struct regulator *regulator;
> +	const char *label;
> +};
> +
> +static const struct reg_default lm3692x_reg_defs[] = {
> +	{LM3692X_EN, 0xf},
> +	{LM3692X_BRT_CTRL, 0x61},
> +	{LM3692X_PWM_CTRL, 0x73},
> +	{LM3692X_BOOST_CTRL, 0x6f},
> +	{LM3692X_AUTO_FREQ_HI, 0x0},
> +	{LM3692X_AUTO_FREQ_LO, 0x0},
> +	{LM3692X_BL_ADJ_THRESH, 0x0},
> +	{LM3692X_BRT_LSB, 0x7},
> +	{LM3692X_BRT_MSB, 0xff},
> +	{LM3692X_FAULT_CTRL, 0x7},
> +};
> +
> +static const struct regmap_config lm3692x_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +
> +	.max_register = LM3692X_FAULT_FLAGS,
> +	.reg_defaults = lm3692x_reg_defs,
> +	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
> +	.cache_type = REGCACHE_RBTREE,
> +};
> +
> +static int lm3692x_fault_check(struct lm3692x_led *led)
> +{
> +	int ret, fault;
> +	unsigned int read_buf;
> +
> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
> +	if (ret)
> +		goto out;
> +
> +	fault = read_buf;
> +
> +	if (fault)
> +		dev_err(&led->client->dev, "Detected a fault 0x%X\n",
> +			fault);
> +out:
> +	return ret;
> +}
> +
> +static int lm3692x_brightness_set(struct led_classdev *led_cdev,
> +				enum led_brightness brt_val)
> +{
> +	struct lm3692x_led *led =
> +			container_of(led_cdev, struct lm3692x_led, led_dev);
> +	int led_brightness = (brt_val << 4) + 7;

Magic numbers?

BRIGHTNESS_SHIFT/MASK maybe?

And below we undo the operation anyway before we write it to the
register. Why not just drop that and to the shift/mask when you write it.

> +	int ret;
> +
> +	if (brt_val == LED_OFF)
> +		led_brightness = 0;
> +
> +	mutex_lock(&led->lock);
> +
> +	ret = lm3692x_fault_check(led);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_MSB,
> +			(led_brightness & 0xff0) >> 4);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot write MSB\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_LSB,
> +			led_brightness & 0x07);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot write LSB\n");
> +		goto out;
> +	}
> +out:
> +	mutex_unlock(&led->lock);
> +	return ret;
> +}
> +
> +static int lm3692x_init(struct lm3692x_led *led)
> +{
> +	int ret;
> +
> +	if (led->regulator) {
> +		ret = regulator_enable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to enable regulator\n");
> +	}
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 1);
> +
> +	ret = lm3692x_fault_check(led);
> +	if (ret) {
> +		dev_err(&led->client->dev, "Cannot read/clear faults\n");
> +		goto out;
> +	}
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Fail writing BRT CTRL\n");
> +	/*
> +	 * For glitch free operation, the following data should
> +	 * only be written while device enable bit is 0
> +	 * Per Section 7.5.14 of the data sheet
> +	 */
> +	ret = regmap_write(led->regmap, LM3692X_PWM_CTRL,
> +		LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming PWM CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
> +			LM3692X_BRHT_MODE_RAMP_MULTI |
> +			LM3692X_BL_ADJ_POL |
> +			LM3692X_RAMP_RATE_250us);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BOOST CTRL\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming AUTO HI FREQ\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming AUTO LO FREQ\n");
> +
> +
> +	ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BL Threshold\n");
> +
> +	ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
> +			LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
> +	if (ret)
> +		dev_err(&led->client->dev, "Failed programming BRT CTRL\n");
> +
> +	return ret;
> +out:
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 0);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to disable regulator\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int lm3692x_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	int ret;
> +	struct lm3692x_led *led;
> +	struct device_node *np = client->dev.of_node;
> +
> +	led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	if (client->dev.of_node) {
> +		ret = of_property_read_string(np, "label", &led->label);
> +		if (ret)
> +			led->label = LM3692X_LED_NAME;
> +	}
> +
> +	led->enable_gpio = devm_gpiod_get_optional(&client->dev,
> +						   "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(led->enable_gpio)) {
> +		ret = PTR_ERR(led->enable_gpio);
> +		dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
> +		return ret;
> +	}
> +
> +	led->regulator = devm_regulator_get(&client->dev, "vled");
> +	if (IS_ERR(led->regulator))
> +		led->regulator = NULL;
> +
> +	led->client = client;
> +	led->led_dev.name = led->label;
> +	led->led_dev.max_brightness = LED_FULL;
> +	led->led_dev.brightness_set_blocking = lm3692x_brightness_set;
> +
> +	mutex_init(&led->lock);
> +
> +	i2c_set_clientdata(client, led);
> +
> +	led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config);
> +	if (IS_ERR(led->regmap)) {
> +		ret = PTR_ERR(led->regmap);
> +		dev_err(&client->dev, "Failed to allocate register map: %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = lm3692x_init(led);
> +	if (ret)
> +		return ret;
> +
> +	ret = led_classdev_register(&client->dev, &led->led_dev);
> +	if (ret) {
> +		dev_err(&client->dev, "led register err: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lm3692x_remove(struct i2c_client *client)
> +{
> +	struct lm3692x_led *led = i2c_get_clientdata(client);
> +	int ret;
> +
> +	led_classdev_unregister(&led->led_dev);
> +
> +	if (led->enable_gpio)
> +		gpiod_direction_output(led->enable_gpio, 0);
> +
> +	if (led->regulator) {
> +		ret = regulator_disable(led->regulator);
> +		if (ret)
> +			dev_err(&led->client->dev,
> +				"Failed to disable regulator\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id lm3692x_id[] = {
> +	{ "lm3692x", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, lm3692x_id);
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id of_lm3692x_leds_match[] = {
> +	{ .compatible = "ti,lm3692x", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
> +#endif
> +
> +static struct i2c_driver lm3692x_driver = {
> +	.driver = {
> +		.name	= "lm3692x",
> +		.of_match_table = of_match_ptr(of_lm3692x_leds_match),
> +	},
> +	.probe		= lm3692x_probe,
> +	.remove		= lm3692x_remove,
> +	.id_table	= lm3692x_id,
> +};
> +module_i2c_driver(lm3692x_driver);
> +
> +MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver");
> +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
> +MODULE_LICENSE("GPL");
> 
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Dan Murphy Nov. 16, 2017, 12:46 p.m. | #8
Andrew

Thanks

On 11/15/2017 09:48 PM, Andrew F. Davis wrote:
> On 11/13/2017 02:50 PM, Dan Murphy wrote:
>> Introducing the LM3692x Dual-String white LED driver.
>>
>> Data sheet is located
>> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
> 
> Looks like v3 is posted but I can't find it in my mailbox :/ but the
> comments below should still be valid.

v3 did post and some of the changes you pointed out were made

> 
>>  drivers/leds/leds-lm3692x.c | 380 ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 380 insertions(+)
>>  create mode 100644 drivers/leds/leds-lm3692x.c
>>
>> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
>> new file mode 100644
>> index 000000000000..beb753abc7b0
>> --- /dev/null
>> +++ b/drivers/leds/leds-lm3692x.c
>> @@ -0,0 +1,380 @@
>> +/*
>> + * TI lm3692x LED Driver
>> + *
>> + * Copyright (C) 2017 Texas Instruments
>> + *
>> + * Author: Dan Murphy <dmurphy@ti.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/i2c.h>
>> +#include <linux/init.h>
>> +#include <linux/leds.h>
>> +#include <linux/regmap.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/slab.h>
>> +
>> +#define LM3692X_LED_NAME	"lm3692x_led"
>> +
>> +#define LM3692X_REV		0x0
>> +#define LM3692X_RESET		0x1
>> +#define LM3692X_EN		0x10
>> +#define LM3692X_BRT_CTRL	0x11
>> +#define LM3692X_PWM_CTRL	0x12
>> +#define LM3692X_BOOST_CTRL	0x13
>> +#define LM3692X_AUTO_FREQ_HI	0x15
>> +#define LM3692X_AUTO_FREQ_LO	0x16
>> +#define LM3692X_BL_ADJ_THRESH	0x17
>> +#define LM3692X_BRT_LSB		0x18
>> +#define LM3692X_BRT_MSB		0x19
>> +#define LM3692X_FAULT_CTRL	0x1e
>> +#define LM3692X_FAULT_FLAGS	0x1f
>> +
>> +#define LM3692X_SW_RESET	BIT(0)
>> +#define LM3692X_DEVICE_EN	BIT(0)
>> +#define LM3692X_LED1_EN		BIT(1)
>> +#define LM3692X_LED2_EN		BIT(2)
>> +
>> +/* Brightness Control Bits */
>> +#define LM3692X_BL_ADJ_POL	BIT(0)
>> +#define LM3692X_RAMP_RATE_125us	0x00
>> +#define LM3692X_RAMP_RATE_250us	BIT(1)
>> +#define LM3692X_RAMP_RATE_500us BIT(2)
>> +#define LM3692X_RAMP_RATE_1ms	(BIT(1) | BIT(2))
>> +#define LM3692X_RAMP_RATE_2ms	BIT(3)
>> +#define LM3692X_RAMP_RATE_4ms	(BIT(3) | BIT(1))
>> +#define LM3692X_RAMP_RATE_8ms	(BIT(2) | BIT(3))
>> +#define LM3692X_RAMP_RATE_16ms	(BIT(1) | BIT(2) | BIT(3))
> 
> The above look like you are just counting in binary, I'd just list the
> numbers then shift them by one.

This is just another way to do it.
Its just a matter of preference.

> 
>> +#define LM3692X_RAMP_EN		BIT(4)
>> +#define LM3692X_BRHT_MODE_REG	0x00
>> +#define LM3692X_BRHT_MODE_PWM	BIT(5)
>> +#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6)
>> +#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6))
>> +#define LM3692X_MAP_MODE_EXP	BIT(7)
>> +
>> +/* PWM Register Bits */
>> +#define LM3692X_PWM_FILTER_100	BIT(0)
>> +#define LM3692X_PWM_FILTER_150	BIT(1)
>> +#define LM3692X_PWM_FILTER_200	(BIT(0) | BIT(1))
>> +#define LM3692X_PWM_HYSTER_1LSB BIT(2)
>> +#define LM3692X_PWM_HYSTER_2LSB	BIT(3)
>> +#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2))
>> +#define LM3692X_PWM_HYSTER_4LSB BIT(4)
>> +#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2))
>> +#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3))
> 
> Same here, looks like a couple below too.

Same as above

> 
>> +#define LM3692X_PWM_POLARITY	BIT(5)
>> +#define LM3692X_PWM_SAMP_4MHZ	BIT(6)
>> +#define LM3692X_PWM_SAMP_24MHZ	BIT(7)
>> +
>> +/* Boost Control Bits */
>> +#define LM3692X_OCP_PROT_1A	BIT(0)
>> +#define LM3692X_OCP_PROT_1_25A	BIT(1)
>> +#define LM3692X_OCP_PROT_1_5A	(BIT(0) | BIT(1))
>> +#define LM3692X_OVP_21V		BIT(2)
>> +#define LM3692X_OVP_25V		BIT(3)
>> +#define LM3692X_OVP_29V		(BIT(2) | BIT(3))
>> +#define LM3692X_MIN_IND_22UH	BIT(4)
>> +#define LM3692X_BOOST_SW_1MHZ	BIT(5)
>> +#define LM3692X_BOOST_SW_NO_SHIFT	BIT(6)
>> +
>> +/* Fault Control Bits */
>> +#define LM3692X_FAULT_CTRL_OVP BIT(0)
>> +#define LM3692X_FAULT_CTRL_OCP BIT(1)
>> +#define LM3692X_FAULT_CTRL_TSD BIT(2)
>> +#define LM3692X_FAULT_CTRL_OPEN BIT(3)
>> +
>> +/* Fault Flag Bits */
>> +#define LM3692X_FAULT_FLAG_OVP BIT(0)
>> +#define LM3692X_FAULT_FLAG_OCP BIT(1)
>> +#define LM3692X_FAULT_FLAG_TSD BIT(2)
>> +#define LM3692X_FAULT_FLAG_SHRT BIT(3)
>> +#define LM3692X_FAULT_FLAG_OPEN BIT(4)
>> +
>> +/**
>> + * struct lm3692x_led -
>> + * @lock - Lock for reading/writing the device
>> + * @client - Pointer to the I2C client
>> + * @led_dev - led class device pointer
>> + * @regmap - Devices register map
>> + * @enable_gpio - VDDIO/EN gpio to enable communication interface
>> + * @regulator - LED supply regulator pointer
>> + * @label - LED label
>> + **/
>> +struct lm3692x_led {
>> +	struct mutex lock;
>> +	struct i2c_client *client;
>> +	struct led_classdev led_dev;
>> +	struct regmap *regmap;
>> +	struct gpio_desc *enable_gpio;
>> +	struct regulator *regulator;
>> +	const char *label;
>> +};
>> +
>> +static const struct reg_default lm3692x_reg_defs[] = {
>> +	{LM3692X_EN, 0xf},
>> +	{LM3692X_BRT_CTRL, 0x61},
>> +	{LM3692X_PWM_CTRL, 0x73},
>> +	{LM3692X_BOOST_CTRL, 0x6f},
>> +	{LM3692X_AUTO_FREQ_HI, 0x0},
>> +	{LM3692X_AUTO_FREQ_LO, 0x0},
>> +	{LM3692X_BL_ADJ_THRESH, 0x0},
>> +	{LM3692X_BRT_LSB, 0x7},
>> +	{LM3692X_BRT_MSB, 0xff},
>> +	{LM3692X_FAULT_CTRL, 0x7},
>> +};
>> +
>> +static const struct regmap_config lm3692x_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +
>> +	.max_register = LM3692X_FAULT_FLAGS,
>> +	.reg_defaults = lm3692x_reg_defs,
>> +	.num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs),
>> +	.cache_type = REGCACHE_RBTREE,
>> +};
>> +
>> +static int lm3692x_fault_check(struct lm3692x_led *led)
>> +{
>> +	int ret, fault;
>> +	unsigned int read_buf;
>> +
>> +	ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
>> +	if (ret)
>> +		goto out;
>> +
>> +	fault = read_buf;
>> +
>> +	if (fault)
>> +		dev_err(&led->client->dev, "Detected a fault 0x%X\n",
>> +			fault);
>> +out:
>> +	return ret;
>> +}
>> +
>> +static int lm3692x_brightness_set(struct led_classdev *led_cdev,
>> +				enum led_brightness brt_val)
>> +{
>> +	struct lm3692x_led *led =
>> +			container_of(led_cdev, struct lm3692x_led, led_dev);
>> +	int led_brightness = (brt_val << 4) + 7;
> 
> Magic numbers?
> 
> BRIGHTNESS_SHIFT/MASK maybe?
> 
> And below we undo the operation anyway before we write it to the
> register. Why not just drop that and to the shift/mask when you write it.
> 

v3 has this changed anyway to something newer.

<snip>

Patch

diff --git a/Documentation/devicetree/bindings/leds/leds-lm3692x.txt b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
new file mode 100644
index 000000000000..cfef67bd4100
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-lm3692x.txt
@@ -0,0 +1,28 @@ 
+* Texas Instruments - LM3692x Highly Efficient Dual-String White LED Driver
+
+The LM36922 is an ultra-compact, highly efficient,
+two string white-LED driver designed for LCD display
+backlighting.
+
+Required properties:
+	- compatible:
+		"ti,lm3692x"
+	- reg -  I2C slave address
+
+Optional properties:
+	- label - Used for naming LEDs
+	- enable-gpio - gpio pin to enable/disable the device.
+	- supply - "vled" - LED supply
+
+Example:
+
+leds: leds@6 {
+	compatible = "ti,lm3692x";
+	reg = <0x36>;
+	label = "backlight_cluster";
+	enable-gpio = <&gpio1 28 GPIO_ACTIVE_HIGH>;
+	vled-supply = <&vbatt>;
+}
+
+For more product information please see the link below:
+http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf