diff options
Diffstat (limited to 'drivers/leds/leds-ktd2692.c')
| -rw-r--r-- | drivers/leds/leds-ktd2692.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/drivers/leds/leds-ktd2692.c b/drivers/leds/leds-ktd2692.c new file mode 100644 index 000000000000..fe05cd113b9d --- /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) { + 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); + } else { + led->mode = KTD2692_MODE_DISABLE; + gpiod_direction_output(led->aux_gpio, KTD2692_LOW); + } + + 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-gpios %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-gpios %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"); |