From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Subject: Re: [PATCH v5 2/2] leds: lm3601x: Introduce the lm3601x LED driver
Date: Fri, 11 May 2018 22:26:39 +0200
Message-ID: <52ea9b2b-5a2d-459e-32cf-3aeb1298e7b9@gmail.com>
References: <20180510174717.26540-1-dmurphy@ti.com>
 <20180510174717.26540-2-dmurphy@ti.com>
 <41267191-1308-6b9b-78fa-2893a525b49a@gmail.com>
 <17630aca-1225-df61-7a5d-a921ecd9c78c@ti.com>
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To: Dan Murphy <dmurphy@ti.com>, robh+dt@kernel.org, mark.rutland@arm.com, pavel@ucw.cz, afd@ti.com
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org
List-Id: devicetree@vger.kernel.org

Hi Dan,

On 05/11/2018 01:56 PM, Dan Murphy wrote:
> Jacek
> 
> Thanks for the review
> 
> On 05/10/2018 03:48 PM, Jacek Anaszewski wrote:
>> Hi Dan,
>>
>> Thank you for the patch.
>>
>> On 05/10/2018 07:47 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@ti.com>
>>> ---
>>>
>>> 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 | 622 ++++++++++++++++++++++++++++++++++++
>>>    3 files changed, 632 insertions(+)
>>>    create mode 100644 drivers/leds/leds-lm3601x.c
>>>
>>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>>> index 2c896c0e69e1..50ae536f343f 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 && OF
>>> +    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..3c00886fbc7a
>>> --- /dev/null
>>> +++ b/drivers/leds/leds-lm3601x.c
>>> @@ -0,0 +1,622 @@
>>> +// 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/
>>> + */
>>
>> Please use uniform "//" comment style here.
> 
> Is this a LEDs only requirement because I checked a few other files and this is
> how the license and header is presented.
> 
> Unless I missed some new change to source code headers.  And the documentation
> does not dictate any change to this.

I started to require this since mixed comment styles look just
awkward to me. Moreover Linus also suggested it in [0]:

"And yes, feel free to replace block comments with // while at it."

Also grep shows the same approach at least in the sound subsystem :-)

>>
>>> +#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_TORCH    0x0
>>> +#define LM3601X_LED_STROBE    0x1
>>> +#define LM3601X_LED_IR        0x2
>>> +
>>> +/* 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_LVL_TRIG    ~BIT(3)
>>> +#define LM3601X_STRB_EDGE_TRIG    BIT(3)
>>> +#define LM3601X_IVFM_EN        BIT(4)
>>> +
>>> +#define LM36010_BOOST_LIMIT_19    ~BIT(5)
>>> +#define LM36010_BOOST_LIMIT_28    BIT(5)
>>> +#define LM36010_BOOST_FREQ_2MHZ    ~BIT(6)
>>> +#define LM36010_BOOST_FREQ_4MHZ    BIT(6)
>>> +#define LM36010_BOOST_MODE_NORM    ~BIT(7)
>>> +#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_MIN_TORCH_I_UA    2400
>>> +#define LM3601X_MIN_STROBE_I_MA    11
>>> +
>>> +#define LM3601X_TIMEOUT_MASK    0x1e
>>> +#define LM3601X_ENABLE_MASK    0x03
>>> +
>>> +enum lm3601x_type {
>>> +    CHIP_LM36010 = 0,
>>> +    CHIP_LM36011,
>>> +};
>>> +
>>> +/**
>>> + * struct lm3601x_max_timeouts -
>>> + * @timeout: timeout value in ms
>>> + * @regval: the value of the register to write
>>> + */
>>> +struct lm3601x_max_timeouts {
>>> +    int timeout;
>>> +    int reg_val;
>>> +};
>>> +
>>> +/**
>>> + * struct lm3601x_led -
>>> + * @lock: Lock for reading/writing the device
>>> + * @regmap: Devices register map
>>> + * @client: Pointer to the I2C client
>>> + * @cdev_torch: led class device pointer for the torch
>>> + * @cdev_ir: led class device pointer for infrared
>>> + * @fled_cdev: flash led class device pointer
>>> + * @strobe_node: DT device node for the strobe
>>> + * @torch: LED label for the torch
>>> + * @strobe: LED label for the strobe
>>> + * @ir: LED label for the infrared
>>> + * @last_flag: last known flags register value
>>> + * @strobe_timeout: the timeout for the strobe
>>> + * @torch_current_max: maximum current for the torch
>>> + * @strobe_current_max: maximum current for the strobe
>>> + * @max_strobe_timeout: maximum timeout for the strobe
>>> + */
>>> +struct lm3601x_led {
>>> +    struct mutex lock;
>>> +    struct regmap *regmap;
>>> +    struct i2c_client *client;
>>> +
>>> +    struct led_classdev cdev_torch;
>>> +    struct led_classdev cdev_ir;
>>> +
>>> +    struct led_classdev_flash fled_cdev;
>>> +
>>> +    struct device_node *strobe_node;
>>> +    struct device_node *torch_node;
>>> +    struct device_node *ir_node;
>>> +
>>> +    char torch[LED_MAX_NAME_SIZE];
>>> +    char strobe[LED_MAX_NAME_SIZE];
>>> +    char ir[LED_MAX_NAME_SIZE];
>>> +
>>> +    unsigned int last_flag;
>>> +    unsigned int strobe_timeout;
>>> +
>>> +    u32 torch_current_max;
>>> +    u32 strobe_current_max;
>>> +    u32 max_strobe_timeout;
>>> +};
>>> +
>>> +static const struct lm3601x_max_timeouts strobe_timeouts[] = {
>>> +    { 40, 0x00 },
>>> +    { 80, 0x01 },
>>> +    { 120, 0x02 },
>>> +    { 160, 0x03 },
>>> +    { 200, 0x04 },
>>> +    { 240, 0x05 },
>>> +    { 280, 0x06 },
>>> +    { 320, 0x07 },
>>> +    { 360, 0x08 },
>>> +    { 400, 0x09 },
>>> +    { 600, 0x0a },
>>> +    { 800, 0x0b },
>>> +    { 1000, 0x0c },
>>> +    { 1200, 0x0d },
>>> +    { 1400, 0x0e },
>>> +    { 1600, 0x0f },
>>> +};
>>> +
>>> +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 = flags_val;
>>> +
>>> +    return led->last_flag;
>>> +}
>>> +
>>> +static int lm3601x_torch_brightness_set(struct led_classdev *cdev,
>>> +                    enum led_brightness brightness)
>>> +{
>>> +    struct lm3601x_led *led =
>>> +        container_of(cdev, struct lm3601x_led, cdev_torch);
>>> +    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_TORCH, LED_OFF);
>>> +        goto out;
>>> +    }
>>> +
>>> +    if (brightness == LED_ON)
>>> +        brightness_val = LED_ON;
>>> +    else
>>> +        brightness_val = (brightness/2);
>>> +
>>> +    ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness_val);
>>> +    if (ret < 0)
>>> +        goto out;
>>> +
>>> +    ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
>>> +                    LM3601X_MODE_TORCH,
>>> +                    LM3601X_MODE_TORCH);
>>> +
>>> +out:
>>> +    mutex_unlock(&led->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
>>> +                bool state)
>>> +{
>>> +    struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
>>> +    int ret;
>>> +    int current_timeout;
>>> +    int reg_count;
>>> +    int i;
>>> +    int timeout_reg_val = 0;
>>> +
>>> +    mutex_lock(&led->lock);
>>> +
>>> +    ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
>>> +    if (ret < 0)
>>> +        goto out;
>>> +
>>> +    reg_count = ARRAY_SIZE(strobe_timeouts);
>>> +    for (i = 0; i < reg_count; i++) {
>>> +        if (led->strobe_timeout > strobe_timeouts[i].timeout)
>>> +            continue;
>>> +
>>> +        if (led->strobe_timeout <= strobe_timeouts[i].timeout) {
>>> +            timeout_reg_val = (strobe_timeouts[i].reg_val << 1);
>>> +            break;
>>> +        }
>>> +
>>> +        ret = -EINVAL;
>>> +        goto out;
>>> +    }
>>> +
>>> +    if (led->strobe_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_STROBE,
>>> +                    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_strobe_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;
>>> +    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;
>>> +    }
>>> +
>>> +    if (brightness == LED_ON)
>>> +        brightness_val = LED_ON;
>>> +    else
>>> +        brightness_val = (brightness/2);
>>> +
>>> +    ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
>>> +
>>> +out:
>>> +    mutex_unlock(&led->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int lm3601x_strobe_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);
>>> +
>>> +    if (timeout > led->max_strobe_timeout)
>>> +        ret = -EINVAL;
>>
>> LED flash core takes care of clamping timeout setting
>> according to the defined constraints.
> 
> OK
> 
>>
>>> +    else
>>> +        led->strobe_timeout = timeout;
>>> +
>>> +    mutex_unlock(&led->lock);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev,
>>> +                bool *state)
>>> +{
>>> +    struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
>>> +    int ret;
>>> +    int strobe_state;
>>> +
>>> +    mutex_lock(&led->lock);
>>> +
>>> +    ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
>>> +    if (ret < 0)
>>> +        goto out;
>>> +
>>> +    *state = strobe_state & LM3601X_MODE_STROBE;
>>> +
>>> +out:
>>> +    mutex_unlock(&led->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int lm3601x_ir_brightness_set(struct led_classdev *cdev,
>>> +                     enum led_brightness brightness)
>>> +{
>>> +    struct lm3601x_led *led =
>>> +        container_of(cdev, struct lm3601x_led, cdev_ir);
>>> +    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_LED_IR,
>>> +                    LED_OFF);
>>> +        goto out;
>>> +    }
>>> +
>>> +    if (brightness == LED_ON)
>>> +        brightness_val = LED_ON;
>>> +    else
>>> +        brightness_val = (brightness/2);
>>> +
>>> +    ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
>>> +    if (ret < 0)
>>> +        goto out;
>>> +
>>> +    ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
>>> +                    LM3601X_MODE_IR_DRV,
>>> +                    LM3601X_MODE_IR_DRV);
>>> +
>>> +out:
>>> +    mutex_unlock(&led->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int lm3601x_strobe_fault_get(struct led_classdev_flash *fled_cdev,
>>> +                u32 *fault)
>>
>> Does the device report only strobe related faults?
> 
> No.  It has under/over voltage and thermal.

I'd remove "strobe" from the function name then.

>>> +{
>>> +    struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
>>> +
>>> +    lm3601x_read_faults(led);
>>> +
>>> +    *fault = led->last_flag;
>>
>> You should translate device specific faults to LED_FAULT* flags.
>> Please compare e.g. drivers/leds/leds-max77693.c or
>> driver/leds/leds-as3645a.c.
> 
> Hmm.  This code is in the max77693.c.  I think the translation should be in the
> read_faults function in this file and not here.

Correct.

> I will add that translation above
> 
>>
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct led_flash_ops strobe_ops = {
>>> +    .strobe_set        = lm3601x_strobe_set,
>>> +    .strobe_get        = lm3601x_strobe_get,
>>> +    .timeout_set        = lm3601x_strobe_timeout_set,
>>> +    .fault_get        = lm3601x_strobe_fault_get,
>>> +};
>>> +
>>> +static int lm3601x_register_leds(struct lm3601x_led *led)
>>> +{
>>> +    struct led_classdev_flash *fled_cdev;
>>> +    struct led_classdev *led_cdev;
>>> +    int err = -ENODEV;
>>> +
>>> +    if (led->torch_node) {
>>> +        led->cdev_torch.name = led->torch;
>>> +        led->cdev_torch.max_brightness = LED_FULL;
>>> +        led->cdev_torch.brightness_set_blocking = lm3601x_torch_brightness_set;
>>> +        err = devm_led_classdev_register(&led->client->dev,
>>> +                &led->cdev_torch);
>>> +        if (err < 0)
>>> +            return err;
>>> +    }
>>> +
>>> +    if (led->strobe_node) {
>>> +        fled_cdev = &led->fled_cdev;
>>> +        fled_cdev->ops = &strobe_ops;
>>> +
>>> +        led_cdev = &fled_cdev->led_cdev;
>>> +        led_cdev->name = led->strobe;
>>> +        led_cdev->max_brightness = LED_FULL;
>>> +        led_cdev->brightness_set_blocking = lm3601x_strobe_brightness_set;
>>> +        led_cdev->flags |= LED_DEV_CAP_FLASH;
>>> +
>>> +        err = led_classdev_flash_register(&led->client->dev,
>>> +                fled_cdev);
>>> +        if (err < 0)
>>> +            return err;
>>> +    }
>>> +
>>> +    if (led->ir_node) {
>>> +        led->cdev_ir.name = led->ir;
>>> +        led->cdev_ir.max_brightness = LED_FULL;
>>> +        led->cdev_ir.brightness_set_blocking =
>>> +                        lm3601x_ir_brightness_set;
>>> +
>>> +        err = devm_led_classdev_register(&led->client->dev,
>>> +                &led->cdev_ir);
>>> +    }
>>> +
>>> +    return err;
>>> +}
>>> +
>>> +static void lm3601x_init_flash_timeout(struct lm3601x_led *led)
>>> +{
>>> +    struct led_flash_setting *setting;
>>> +
>>> +    setting = &led->fled_cdev.timeout;
>>> +    setting->min = strobe_timeouts[0].timeout;
>>> +    setting->max = led->max_strobe_timeout;
>>> +    setting->step = 40;
>>> +    setting->val = led->max_strobe_timeout;
>>> +}
>>> +
>>> +static int lm3601x_parse_node(struct lm3601x_led *led,
>>> +                  struct device_node *node)
>>> +{
>>> +    struct device_node *child_node;
>>> +    const char *name;
>>> +    int ret = -ENODEV;
>>> +
>>> +    for_each_available_child_of_node(node, child_node) {
>>> +        u32 id = 0;
>>> +
>>> +        of_property_read_u32(child_node, "reg", &id);
>>> +
>>> +        switch (id) {
>>> +        case LM3601X_LED_TORCH:
>>> +            led->torch_node = of_node_get(child_node);
>>> +            break;
>>> +        case LM3601X_LED_STROBE:
>>> +            led->strobe_node = of_node_get(child_node);
>>> +            break;
>>> +        case LM3601X_LED_IR:
>>> +            led->ir_node = of_node_get(child_node);
>>> +            break;
>>> +        default:
>>> +            dev_warn(&led->client->dev,
>>> +                 "unknown LED %u encountered, ignoring\n", id);
>>> +            break;
>>> +        }
>>> +    }
>>> +
>>> +    if (led->torch_node) {
>>> +        ret = of_property_read_string(led->torch_node, "label", &name);
>>> +        if (!ret)
>>> +            snprintf(led->torch, sizeof(led->torch),
>>> +                "%s:%s", led->torch_node->name, name);
>>> +        else
>>> +            snprintf(led->torch, sizeof(led->torch),
>>> +                "%s:torch", led->torch_node->name);
>>> +        ret = of_property_read_u32(led->torch_node, "led-max-microamp",
>>> +                    &led->torch_current_max);
>>> +        if (ret < 0) {
>>> +            led->torch_current_max = LM3601X_MIN_TORCH_I_UA;
>>> +            dev_warn(&led->client->dev,
>>> +                "led-max-microamp DT property missing\n");
>>> +        }
>>> +
>>> +        of_node_put(led->torch_node);
>>> +    }
>>> +
>>> +    if (led->strobe_node) {
>>> +        ret = of_property_read_string(led->strobe_node, "label", &name);
>>> +        if (!ret)
>>> +            snprintf(led->strobe, sizeof(led->strobe),
>>> +                "%s:%s", led->strobe_node->name, name);
>>> +        else
>>> +            snprintf(led->strobe, sizeof(led->strobe),
>>> +                "%s::strobe", led->strobe_node->name);
>>> +
>>> +        ret = of_property_read_u32(led->strobe_node,
>>> +                    "flash-max-microamp",
>>> +                    &led->strobe_current_max);
>>> +        if (ret < 0) {
>>> +            led->strobe_current_max = LM3601X_MIN_STROBE_I_MA;
>>> +            dev_warn(&led->client->dev,
>>> +                 "flash-max-microamp DT property missing\n");
>>> +        }
>>> +
>>> +        ret = of_property_read_u32(led->strobe_node,
>>> +                    "flash-max-timeout-us",
>>> +                    &led->max_strobe_timeout);
>>> +        if (ret < 0) {
>>> +            led->max_strobe_timeout = strobe_timeouts[0].reg_val;
>>> +            dev_warn(&led->client->dev,
>>> +                 "flash-max-timeout-us DT property missing\n");
>>> +        }
>>
>> Common LED bindings state that flash-max-microamp and
>> flash-max-timeout-us properties are mandatory.
> 
> OK.
> 
>>
>>> +
>>> +        lm3601x_init_flash_timeout(led);
>>> +
>>> +        of_node_put(led->strobe_node);
>>> +    }
>>> +
>>> +    if (led->ir_node) {
>>> +        ret = of_property_read_string(led->ir_node, "label", &name);
>>> +        if (!ret)
>>> +            snprintf(led->ir, sizeof(led->ir),
>>> +                "%s:%s", led->ir_node->name, name);
>>> +        else
>>> +            snprintf(led->ir, sizeof(led->ir),
>>> +                "%s::infrared", led->ir_node->name);
>>> +
>>> +        of_node_put(led->ir_node);
>>> +    }
>>> +
>>> +    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(struct lm3601x_led), GFP_KERNEL);
>>> +    if (!led)
>>> +        return -ENOMEM;
>>> +
>>> +    err = lm3601x_parse_node(led, client->dev.of_node);
>>> +    if (err < 0)
>>> +        return -ENODEV;
>>> +
>>> +    led->client = client;
>>> +    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);
>>> +    i2c_set_clientdata(client, led);
>>> +    err = lm3601x_register_leds(led);
>>> +
>>> +    return err;
>>> +}
>>> +
>>> +static int lm3601x_remove(struct i2c_client *client)
>>> +{
>>> +    struct lm3601x_led *led = i2c_get_clientdata(client);
>>> +
>>> +    regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
>>> +               LM3601X_ENABLE_MASK,
>>> +               LM3601X_MODE_STANDBY);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +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@ti.com>");
>>> +MODULE_LICENSE("GPL v2");
>>>
>>
> 
> 

[0] https://lkml.org/lkml/2017/11/2/715

-- 
Best regards,
Jacek Anaszewski