Jacek

Thanks for the review

On 11/29/2017 03:52 PM, Jacek Anaszewski wrote:
> Hi Dan,
> 
> Thanks for the update.
> 
> On 11/28/2017 09:40 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 <dmur...@ti.com>
>> ---
>> v4 - Converted to devm led class register, changed MODULE_LICENSE to GPL v2, 
>> set the led name based on child node name or label entry, removed fault and
>> returned read_buf for fault checking, added mutex_destroy to remove function,
>> and removed LED_FULL - https://patchwork.kernel.org/patch/10060109/
>>
>> v3 - Add missing Makefile and Kconfig from v1 and v2 - 
>> https://patchwork.kernel.org/patch/10060075/
>> v2 - Added data sheet link, fixed linuxdoc format, returned on failure in 
>> init
>> routine, return on fault_check failure, updated brightness calculation and
>> fixed capitalization issue - https://patchwork.kernel.org/patch/10056675/
>>
>>  drivers/leds/Kconfig        |   7 +
>>  drivers/leds/Makefile       |   1 +
>>  drivers/leds/leds-lm3692x.c | 382 
>> ++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 390 insertions(+)
>>  create mode 100644 drivers/leds/leds-lm3692x.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 318a28fd58fe..c0583f1bc8ea 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -137,6 +137,13 @@ config LEDS_LM3642
>>        converter plus 1.5A constant current driver for a high-current
>>        white LED.
>>  
>> +config LEDS_LM3692X
>> +    tristate "LED support for LM3692x Chips"
>> +    depends on LEDS_CLASS && I2C
>> +    select REGMAP_I2C
>> +    help
>> +      This option enables support for the TI LM3692x family
>> +      of white LED string drivers used for backlighting.
>>  
>>  config LEDS_LOCOMO
>>      tristate "LED Support for Locomo device"
>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>> index a2a6b5a4f86d..987884a5b9a5 100644
>> --- a/drivers/leds/Makefile
>> +++ b/drivers/leds/Makefile
>> @@ -74,6 +74,7 @@ obj-$(CONFIG_LEDS_PM8058)          += leds-pm8058.o
>>  obj-$(CONFIG_LEDS_MLXCPLD)          += leds-mlxcpld.o
>>  obj-$(CONFIG_LEDS_NIC78BX)          += leds-nic78bx.o
>>  obj-$(CONFIG_LEDS_MT6323)           += leds-mt6323.o
>> +obj-$(CONFIG_LEDS_LM3692X)          += leds-lm3692x.o
>>  
>>  # LED SPI Drivers
>>  obj-$(CONFIG_LEDS_DAC124S085)               += leds-dac124s085.o
>> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c
>> new file mode 100644
>> index 000000000000..fcf0573fb985
>> --- /dev/null
>> +++ b/drivers/leds/leds-lm3692x.c
>> @@ -0,0 +1,382 @@
>> +/*
>> + * TI lm3692x LED Driver
>> + *
>> + * Copyright (C) 2017 Texas Instruments
>> + *
>> + * Author: Dan Murphy <dmur...@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.
>> + *
>> + * Data sheet is located
>> + * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf
>> + */
>> +
>> +#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_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
> 
> s/led class/LED class/
> 

ACK

>> + * @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;
>> +    unsigned int read_buf;
>> +
>> +    ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
>> +    if (ret)
>> +            return ret;
>> +
>> +    if (read_buf)
>> +            dev_err(&led->client->dev, "Detected a fault 0x%X\n",
>> +                    read_buf);
>> +
>> +    return read_buf;
>> +}
>> +
>> +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 ret;
>> +    int led_brightness_lsb = (brt_val >> 5);
>> +
>> +    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, brt_val);
>> +    if (ret) {
>> +            dev_err(&led->client->dev, "Cannot write MSB\n");
>> +            goto out;
>> +    }
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb);
>> +    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");
>> +                    return ret;
>> +            }
>> +    }
>> +
>> +    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)
>> +            goto out;
>> +
>> +    /*
>> +     * 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)
>> +            goto out;
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL,
>> +                    LM3692X_BRHT_MODE_RAMP_MULTI |
>> +                    LM3692X_BL_ADJ_POL |
>> +                    LM3692X_RAMP_RATE_250us);
>> +    if (ret)
>> +            goto out;
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00);
>> +    if (ret)
>> +            goto out;
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00);
>> +    if (ret)
>> +            goto out;
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00);
>> +    if (ret)
>> +            goto out;
>> +
>> +    ret = regmap_write(led->regmap, LM3692X_BRT_CTRL,
>> +                    LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB);
>> +    if (ret)
>> +            goto out;
>> +
>> +    return ret;
>> +out:
>> +    dev_err(&led->client->dev, "Fail writing initialization values\n");
>> +
>> +    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;
>> +    struct device_node *child_node;
>> +
>> +    led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL);
>> +    if (!led)
>> +            return -ENOMEM;
>> +
>> +    for_each_available_child_of_node(np, child_node) {
>> +            led->led_dev.name = of_get_property(child_node, "label", NULL) 
>> ? :
>> +                                             child_node->name;
> 
> You need also devicename segment in the LED class device name.
> You can take it from the parent node name. Please follow what has been
> done for drivers/leds/leds-as3645a.c, with a reservation that your
> DT binding is correct, as it doesn't contain devicename segment,
> which turned out to be against DT specification. So you'll need
> to tweak a bit leds-as3645a.c way of composing LED class device
> name to take devicename from parent DT node also for the case
> when DT label property is present.
> 
> I will be convenient to create some generic LED core function
> for composing LED class device name basing on DT data.
> 
> All these findings are quite recent, that's why there is no
> well established approach to the problem.
> 

ACK

>> +
>> +            led->led_dev.default_trigger = of_get_property(child_node,
>> +                                                "linux,default-trigger",
>> +                                                NULL);
>> +    };
>> +
>> +    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.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 = devm_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);
> 
> You don't need it if registering with devm* API.
> 

ACK

>> +
>> +    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");
>> +    }
>> +
>> +    mutex_destroy(&led->lock);
>> +
>> +    return 0;
>> +}
>> +
>> +static const struct i2c_device_id lm3692x_id[] = {
>> +    { "lm36922", 0 },
>> +    { "lm36923", 1 },
>> +    { }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, lm3692x_id);
>> +
>> +#ifdef CONFIG_OF
> 
> We seem to entirely rely on OF.
> Let's drop this guard and add OF dependency to Kconfig.
> 

ACK

>> +static const struct of_device_id of_lm3692x_leds_match[] = {
>> +    { .compatible = "ti,lm36922", },
>> +    { .compatible = "ti,lm36923", },
>> +    {},
>> +};
>> +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),
> 
> Also of_match_ptr() will be redundant then.
> 

ACK

>> +    },
>> +    .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 <dmur...@ti.com>");
>> +MODULE_LICENSE("GPL v2");
>>
> 


-- 
------------------
Dan Murphy

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