Re: [PATCH v10 2/2] leds: lm3692x: Introduce LM3692x dual string driver
From: Dan Murphy
Date: Tue Dec 12 2017 - 13:05:18 EST
One minor change
On 12/12/2017 11:00 AM, 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@xxxxxx>
> ---
>
> v10 - No changes - https://patchwork.kernel.org/patch/10105651/
>
> v9 - Change the no DT label case to pull the device name from the i2c_id struct
> so that the device name can be part of the sysfs node - https://patchwork.kernel.org/patch/10093759/
> v8 - No changes
> v7 - Reverted back to creating the LED label within the driver -
> https://patchwork.kernel.org/patch/10087473/
> v6 - Use new LED API to compose LED label as opposed to creating it. -
> https://patchwork.kernel.org/patch/10085565/
> v5 - Added OF dependency in Kconfig, added extra fault flag read to ensure that
> if a fault exists and it is not a artifact, fixed LED class label to be derived
> from either the DT child "label" node or create a label based on
> parent_node_name:led color:trigger, removed ifdef for CONFIG_OF and removed
> of_match_ptr - https://patchwork.kernel.org/patch/10081073/
> 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 | 393 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 401 insertions(+)
> create mode 100644 drivers/leds/leds-lm3692x.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 318a28fd58fe..1d215b39cefd 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 && OF
> + 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..7077f9459bce
> --- /dev/null
> +++ b/drivers/leds/leds-lm3692x.c
> @@ -0,0 +1,393 @@
> +/*
> + * TI lm3692x LED Driver
> + *
> + * Copyright (C) 2017 Texas Instruments
> + *
> + * Author: Dan Murphy <dmurphy@xxxxxx>
> + *
> + * 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>
> +#include <uapi/linux/uleds.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
> + * @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;
> + char label[LED_MAX_NAME_SIZE];
> +};
> +
> +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);
> +
> + /* The first read may clear the fault. Check again to see if the fault
> + * still exits and return that value.
> + */
> + regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf);
> + if (read_buf)
> + dev_err(&led->client->dev, "Second read of fault flags 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;
> + const char *name;
> +
> + 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.default_trigger = of_get_property(child_node,
> + "linux,default-trigger",
> + NULL);
> +
> + ret = of_property_read_string(child_node, "label", &name);
> + if (!ret)
> + snprintf(led->label, sizeof(led->label), "%s:%s",
> + np->name, name);
This needs to be id->name like below
Dan
> + else
> + snprintf(led->label, sizeof(led->label),
> + "%s::backlight_cluster", id->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.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;
> +
> + 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);
> +
> +static const struct of_device_id of_lm3692x_leds_match[] = {
> + { .compatible = "ti,lm36922", },
> + { .compatible = "ti,lm36923", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match);
> +
> +static struct i2c_driver lm3692x_driver = {
> + .driver = {
> + .name = "lm3692x",
> + .of_match_table = 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@xxxxxx>");
> +MODULE_LICENSE("GPL v2");
>
--
------------------
Dan Murphy