Re: [PATCH v8 3/3] leds: Add ktd2692 flash LED driver

Ingi Kim
2015-05-11T02:24:26Z

Hi Jacek,
Thanks for the review

I can improve this driver for your attention
I'm trying to rebase source code for merging it and resending soon.

Thank you

On 2015년 05월 08일 17:33, Jacek Anaszewski wrote:
> Hi Ingi,
>
> Thanks for the update. It looks like we're almost there.
> I can see only two minor issues.
>
> On 05/08/2015 05:03 AM, Ingi Kim wrote:
>> This patch adds a driver to support the ktd2692 flash LEDs.
>> ktd2692 can control flash current by ExpressWire interface.
>>
>> Signed-off-by: Ingi Kim <ingi2.kim@samsung.com>
>> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
>> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com>
>> ---
>> drivers/leds/Kconfig | 9 +
>> drivers/leds/Makefile | 1 +
>> drivers/leds/leds-ktd2692.c | 443 ++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 453 insertions(+)
>> create mode 100644 drivers/leds/leds-ktd2692.c
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 51059bb..bfbdbd1 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -505,6 +505,15 @@ config LEDS_MENF21BMC
>> This driver can also be built as a module. If so the module
>> will be called leds-menf21bmc.
>>
>> +config LEDS_KTD2692
>> + tristate "KTD2692 LED flash support"
>
> Please keep the style of description in line with the existing
> drivers. How about:
>
> "LED support for KTD2692 flash LED controller"
>

Sure, I'll change it

>> + depends on LEDS_CLASS_FLASH && GPIOLIB && OF
>> + help
>> + This option enables support for KTD2692 LED flash connected
>> + through ExpressWire interface.
>> +
>> + Say Y to enable this driver.
>> +
>> comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
>>
>> config LEDS_BLINKM
>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>> index a739ae2..ed5ed79 100644
>> --- a/drivers/leds/Makefile
>> +++ b/drivers/leds/Makefile
>> @@ -59,6 +59,7 @@ obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
>> obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
>> obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o
>> obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
>> +obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o
>>
>> # LED SPI Drivers
>> obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
>> diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c
>> new file mode 100644
>> index 0000000..9d878a4
>> --- /dev/null
>> +++ b/drivers/leds/leds-ktd2692.c
>> @@ -0,0 +1,443 @@
>> +/*
>> + * LED driver : leds-ktd2692.c
>> + *
>> + * Copyright (C) 2015 Samsung Electronics
>> + * Ingi Kim <ingi2.kim@samsung.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/delay.h>
>> +#include <linux/err.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/led-class-flash.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regulator/consumer.h>
>> +#include <linux/workqueue.h>
>> +
>> +/* Value related the movie mode */
>> +#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
>> +#define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
>> +#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE 8
>> +
>> +/* Value related the flash mode */
>> +#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
>> +#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
>> +#define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)
>> +
>> +/* Macro for getting offset of flash timeout */
>> +#define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))
>> +
>> +/* Base register address */
>> +#define KTD2692_REG_LVP_BASE 0x00
>> +#define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
>> +#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
>> +#define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
>> +#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
>> +#define KTD2692_REG_MODE_BASE 0xA0
>> +
>> +/* Set bit coding time for expresswire interface */
>> +#define KTD2692_TIME_RESET_US 700
>> +#define KTD2692_TIME_DATA_START_TIME_US 10
>> +#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
>> +#define KTD2692_TIME_LOW_END_OF_DATA_US 10
>> +#define KTD2692_TIME_SHORT_BITSET_US 4
>> +#define KTD2692_TIME_LONG_BITSET_US 12
>> +
>> +/* KTD2692 default length of name */
>> +#define KTD2692_NAME_LENGTH 20
>> +
>> +enum ktd2692_bitset {
>> + KTD2692_LOW = 0,
>> + KTD2692_HIGH,
>> +};
>> +
>> +/* Movie / Flash Mode Control */
>> +enum ktd2692_led_mode {
>> + KTD2692_MODE_DISABLE = 0, /* default */
>> + KTD2692_MODE_MOVIE,
>> + KTD2692_MODE_FLASH,
>> +};
>> +
>> +struct ktd2692_led_config_data {
>> + /* maximum LED current in movie mode */
>> + u32 movie_max_microamp;
>> + /* maximum LED current in flash mode */
>> + u32 flash_max_microamp;
>> + /* maximum flash timeout */
>> + u32 flash_max_timeout;
>> + /* max LED brightness level */
>> + enum led_brightness max_brightness;
>> +};
>> +
>> +struct ktd2692_context {
>> + /* Related LED Flash class device */
>> + struct led_classdev_flash fled_cdev;
>> +
>> + /* secures access to the device */
>> + struct mutex lock;
>> + struct regulator *regulator;
>> + struct work_struct work_brightness_set;
>> +
>> + struct gpio_desc *aux_gpio;
>> + struct gpio_desc *ctrl_gpio;
>> +
>> + enum ktd2692_led_mode mode;
>> + enum led_brightness torch_brightness;
>> +};
>> +
>> +static struct ktd2692_context *fled_cdev_to_led(
>> + struct led_classdev_flash *fled_cdev)
>> +{
>> + return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
>> +}
>> +
>> +static void ktd2692_expresswire_start(struct ktd2692_context *led)
>> +{
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> + udelay(KTD2692_TIME_DATA_START_TIME_US);
>> +}
>> +
>> +static void ktd2692_expresswire_reset(struct ktd2692_context *led)
>> +{
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> + udelay(KTD2692_TIME_RESET_US);
>> +}
>> +
>> +static void ktd2692_expresswire_end(struct ktd2692_context *led)
>> +{
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> + udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> + udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
>> +}
>> +
>> +static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
>> +{
>> + /*
>> + * The Low Bit(0) and High Bit(1) is based on a time detection
>> + * algorithm between time low and time high
>> + * Time_(L_LB) : Low time of the Low Bit(0)
>> + * Time_(H_LB) : High time of the LOW Bit(0)
>> + * Time_(L_HB) : Low time of the High Bit(1)
>> + * Time_(H_HB) : High time of the High Bit(1)
>> + *
>> + * It can be simplified to:
>> + * Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
>> + * High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
>> + * HIGH ___ ____ _.. _________ ___
>> + * |_________| |_.. |____| |__|
>> + * LOW <L_LB> <H_LB> <L_HB> <H_HB>
>> + * [ Low Bit (0) ] [ High Bit(1) ]
>> + */
>> + if (bit) {
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> + udelay(KTD2692_TIME_SHORT_BITSET_US);
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> + udelay(KTD2692_TIME_LONG_BITSET_US);
>> + } else {
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
>> + udelay(KTD2692_TIME_LONG_BITSET_US);
>> + gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
>> + udelay(KTD2692_TIME_SHORT_BITSET_US);
>> + }
>> +}
>> +
>> +static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
>> +{
>> + int i;
>> +
>> + ktd2692_expresswire_start(led);
>> + for (i = 7; i >= 0; i--)
>> + ktd2692_expresswire_set_bit(led, value & BIT(i));
>> + ktd2692_expresswire_end(led);
>> +}
>> +
>> +static void ktd2692_brightness_set(struct ktd2692_context *led,
>> + enum led_brightness brightness)
>> +{
>> + mutex_lock(&led->lock);
>> +
>> + if (brightness == LED_OFF) {
>> + led->mode = KTD2692_MODE_DISABLE;
>> + gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> + } else {
>> + ktd2692_expresswire_write(led, brightness |
>> + KTD2692_REG_MOVIE_CURRENT_BASE);
>> + led->mode = KTD2692_MODE_MOVIE;
>> + }
>> +
>> + ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
>> + mutex_unlock(&led->lock);
>> +}
>> +
>> +static void ktd2692_brightness_set_work(struct work_struct *work)
>> +{
>> + struct ktd2692_context *led =
>> + container_of(work, struct ktd2692_context, work_brightness_set);
>> +
>> + ktd2692_brightness_set(led, led->torch_brightness);
>> +}
>> +
>> +static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
>> + enum led_brightness brightness)
>> +{
>> + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
>> + struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> +
>> + led->torch_brightness = brightness;
>> + schedule_work(&led->work_brightness_set);
>> +}
>> +
>> +static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
>> + enum led_brightness brightness)
>> +{
>> + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
>> + struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> +
>> + ktd2692_brightness_set(led, brightness);
>> +
>> + return 0;
>> +}
>> +
>> +static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
>> + bool state)
>> +{
>> + struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
>> + struct led_flash_setting *timeout = &fled_cdev->timeout;
>> + u32 flash_tm_reg;
>> +
>> + mutex_lock(&led->lock);
>> +
>> + if (state == 0) {
>
> Coccinelle raises a warning here:
>
> drivers/leds/leds-ktd2692.c:217:5-10: WARNING: Comparison of bool to 0/1
>
> I had to fix it also in my leds-aat1290 driver recently:)
>

Ok, I'll refer to your driver code
Thank you, so kindly :)

>> + led->mode = KTD2692_MODE_DISABLE;
>> + gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> + } else {
>> + flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
>> + ktd2692_expresswire_write(led, flash_tm_reg
>> + | KTD2692_REG_FLASH_TIMEOUT_BASE);
>> +
>> + led->mode = KTD2692_MODE_FLASH;
>> + gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
>> + }
>> +
>> + ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
>> +
>> + fled_cdev->led_cdev.brightness = LED_OFF;
>> + led->mode = KTD2692_MODE_DISABLE;
>> +
>> + mutex_unlock(&led->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
>> + u32 timeout)
>> +{
>> + return 0;
>> +}
>> +
>> +static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
>> +{
>> + u32 offset, step;
>> + u32 movie_current_microamp;
>> +
>> + offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
>> + step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
>> + / KTD2692_MOVIE_MODE_CURRENT_LEVELS;
>> +
>> + do {
>> + movie_current_microamp = step * offset;
>> + offset--;
>> + } while ((movie_current_microamp > cfg->movie_max_microamp) &&
>> + (offset > 0));
>> +
>> + cfg->max_brightness = offset;
>> +}
>> +
>> +static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
>> + struct ktd2692_led_config_data *cfg)
>> +{
>> + struct led_flash_setting *setting;
>> +
>> + setting = &fled_cdev->timeout;
>> + setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
>> + setting->max = cfg->flash_max_timeout;
>> + setting->step = cfg->flash_max_timeout
>> + / (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
>> + setting->val = cfg->flash_max_timeout;
>> +}
>> +
>> +static void ktd2692_setup(struct ktd2692_context *led)
>> +{
>> + led->mode = KTD2692_MODE_DISABLE;
>> + ktd2692_expresswire_reset(led);
>> + gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
>> +
>> + ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
>> + | KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
>> + ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
>> + | KTD2692_REG_FLASH_CURRENT_BASE);
>> +}
>> +
>> +static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
>> + struct ktd2692_led_config_data *cfg)
>> +{
>> + struct device_node *np = dev->of_node;
>> + struct device_node *child_node;
>> + int ret;
>> +
>> + if (!dev->of_node)
>> + return -ENXIO;
>> +
>> + led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
>> + if (IS_ERR(led->ctrl_gpio)) {
>> + ret = PTR_ERR(led->ctrl_gpio);
>> + dev_err(dev, "cannot get ctrl-gpio %d\n", ret);
>> + return ret;
>> + }
>> +
>> + led->aux_gpio = devm_gpiod_get(dev, "aux");
>> + if (IS_ERR(led->aux_gpio)) {
>> + ret = PTR_ERR(led->aux_gpio);
>> + dev_err(dev, "cannot get aux-gpio %d\n", ret);
>> + return ret;
>> + }
>> +
>> + led->regulator = devm_regulator_get(dev, "vin");
>> + if (IS_ERR(led->regulator))
>> + led->regulator = NULL;
>> +
>> + if (led->regulator) {
>> + ret = regulator_enable(led->regulator);
>> + if (ret)
>> + dev_err(dev, "Failed to enable supply: %d\n", ret);
>> + }
>> +
>> + child_node = of_get_next_available_child(np, NULL);
>> + if (!child_node) {
>> + dev_err(dev, "No DT child node found for connected LED.\n");
>> + return -EINVAL;
>> + }
>> +
>> + led->fled_cdev.led_cdev.name =
>> + of_get_property(child_node, "label", NULL) ? : child_node->name;
>> +
>> + ret = of_property_read_u32(child_node, "led-max-microamp",
>> + &cfg->movie_max_microamp);
>> + if (ret) {
>> + dev_err(dev, "failed to parse led-max-microamp\n");
>> + return ret;
>> + }
>> +
>> + ret = of_property_read_u32(child_node, "flash-max-microamp",
>> + &cfg->flash_max_microamp);
>> + if (ret) {
>> + dev_err(dev, "failed to parse flash-max-microamp\n");
>> + return ret;
>> + }
>> +
>> + ret = of_property_read_u32(child_node, "flash-max-timeout-us",
>> + &cfg->flash_max_timeout);
>> + if (ret)
>> + dev_err(dev, "failed to parse flash-max-timeout-us\n");
>> +
>> + of_node_put(child_node);
>> + return ret;
>> +}
>> +
>> +static const struct led_flash_ops flash_ops = {
>> + .strobe_set = ktd2692_led_flash_strobe_set,
>> + .timeout_set = ktd2692_led_flash_timeout_set,
>> +};
>> +
>> +static int ktd2692_probe(struct platform_device *pdev)
>> +{
>> + struct ktd2692_context *led;
>> + struct led_classdev *led_cdev;
>> + struct led_classdev_flash *fled_cdev;
>> + struct ktd2692_led_config_data led_cfg;
>> + int ret;
>> +
>> + led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
>> + if (!led)
>> + return -ENOMEM;
>> +
>> + fled_cdev = &led->fled_cdev;
>> + led_cdev = &fled_cdev->led_cdev;
>> +
>> + ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
>> + if (ret)
>> + return ret;
>> +
>> + ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
>> + ktd2692_init_movie_current_max(&led_cfg);
>> +
>> + fled_cdev->ops = &flash_ops;
>> +
>> + led_cdev->max_brightness = led_cfg.max_brightness;
>> + led_cdev->brightness_set = ktd2692_led_brightness_set;
>> + led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
>> + led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
>> +
>> + mutex_init(&led->lock);
>> + INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
>> +
>> + platform_set_drvdata(pdev, led);
>> +
>> + ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
>> + if (ret) {
>> + dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
>> + mutex_destroy(&led->lock);
>> + return ret;
>> + }
>> +
>> + ktd2692_setup(led);
>> +
>> + return 0;
>> +}
>> +
>> +static int ktd2692_remove(struct platform_device *pdev)
>> +{
>> + struct ktd2692_context *led = platform_get_drvdata(pdev);
>> + int ret;
>> +
>> + led_classdev_flash_unregister(&led->fled_cdev);
>> + cancel_work_sync(&led->work_brightness_set);
>> +
>> + if (led->regulator) {
>> + ret = regulator_disable(led->regulator);
>> + if (ret)
>> + dev_err(&pdev->dev,
>> + "Failed to disable supply: %d\n", ret);
>> + }
>> +
>> + mutex_destroy(&led->lock);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id ktd2692_match[] = {
>> + { .compatible = "kinetic,ktd2692", },
>> + { /* sentinel */ },
>> +};
>> +
>> +static struct platform_driver ktd2692_driver = {
>> + .driver = {
>> + .name = "ktd2692",
>> + .of_match_table = ktd2692_match,
>> + },
>> + .probe = ktd2692_probe,
>> + .remove = ktd2692_remove,
>> +};
>> +
>> +module_platform_driver(ktd2692_driver);
>> +
>> +MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
>> +MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
>> +MODULE_LICENSE("GPL v2");
>>
>
>