diff options
Diffstat (limited to 'drivers/leds/leds-aat1290.c')
| -rw-r--r-- | drivers/leds/leds-aat1290.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/drivers/leds/leds-aat1290.c b/drivers/leds/leds-aat1290.c new file mode 100644 index 000000000..589484b22 --- /dev/null +++ b/drivers/leds/leds-aat1290.c @@ -0,0 +1,556 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * LED Flash class driver for the AAT1290 + * 1.5A Step-Up Current Regulator for Flash LEDs + * + * Copyright (C) 2015, Samsung Electronics Co., Ltd. + * Author: Jacek Anaszewski <j.anaszewski@samsung.com> + */ + +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/led-class-flash.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <media/v4l2-flash-led-class.h> + +#define AAT1290_MOVIE_MODE_CURRENT_ADDR 17 +#define AAT1290_MAX_MM_CURR_PERCENT_0 16 +#define AAT1290_MAX_MM_CURR_PERCENT_100 1 + +#define AAT1290_FLASH_SAFETY_TIMER_ADDR 18 + +#define AAT1290_MOVIE_MODE_CONFIG_ADDR 19 +#define AAT1290_MOVIE_MODE_OFF 1 +#define AAT1290_MOVIE_MODE_ON 3 + +#define AAT1290_MM_CURRENT_RATIO_ADDR 20 +#define AAT1290_MM_TO_FL_1_92 1 + +#define AAT1290_MM_TO_FL_RATIO 1000 / 1920 +#define AAT1290_MAX_MM_CURRENT(fl_max) (fl_max * AAT1290_MM_TO_FL_RATIO) + +#define AAT1290_LATCH_TIME_MIN_US 500 +#define AAT1290_LATCH_TIME_MAX_US 1000 +#define AAT1290_EN_SET_TICK_TIME_US 1 +#define AAT1290_FLEN_OFF_DELAY_TIME_US 10 +#define AAT1290_FLASH_TM_NUM_LEVELS 16 +#define AAT1290_MM_CURRENT_SCALE_SIZE 15 + +#define AAT1290_NAME "aat1290" + + +struct aat1290_led_config_data { + /* maximum LED current in movie mode */ + u32 max_mm_current; + /* maximum LED current in flash mode */ + u32 max_flash_current; + /* maximum flash timeout */ + u32 max_flash_tm; + /* external strobe capability */ + bool has_external_strobe; + /* max LED brightness level */ + enum led_brightness max_brightness; +}; + +struct aat1290_led { + /* platform device data */ + struct platform_device *pdev; + /* secures access to the device */ + struct mutex lock; + + /* corresponding LED Flash class device */ + struct led_classdev_flash fled_cdev; + /* V4L2 Flash device */ + struct v4l2_flash *v4l2_flash; + + /* FLEN pin */ + struct gpio_desc *gpio_fl_en; + /* EN|SET pin */ + struct gpio_desc *gpio_en_set; + /* movie mode current scale */ + int *mm_current_scale; + /* device mode */ + bool movie_mode; + /* brightness cache */ + unsigned int torch_brightness; +}; + +static struct aat1290_led *fled_cdev_to_led( + struct led_classdev_flash *fled_cdev) +{ + return container_of(fled_cdev, struct aat1290_led, fled_cdev); +} + +static struct led_classdev_flash *led_cdev_to_fled_cdev( + struct led_classdev *led_cdev) +{ + return container_of(led_cdev, struct led_classdev_flash, led_cdev); +} + +static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value) +{ + int i; + + gpiod_direction_output(led->gpio_fl_en, 0); + gpiod_direction_output(led->gpio_en_set, 0); + + udelay(AAT1290_FLEN_OFF_DELAY_TIME_US); + + /* write address */ + for (i = 0; i < addr; ++i) { + udelay(AAT1290_EN_SET_TICK_TIME_US); + gpiod_direction_output(led->gpio_en_set, 0); + udelay(AAT1290_EN_SET_TICK_TIME_US); + gpiod_direction_output(led->gpio_en_set, 1); + } + + usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US); + + /* write data */ + for (i = 0; i < value; ++i) { + udelay(AAT1290_EN_SET_TICK_TIME_US); + gpiod_direction_output(led->gpio_en_set, 0); + udelay(AAT1290_EN_SET_TICK_TIME_US); + gpiod_direction_output(led->gpio_en_set, 1); + } + + usleep_range(AAT1290_LATCH_TIME_MIN_US, AAT1290_LATCH_TIME_MAX_US); +} + +static void aat1290_set_flash_safety_timer(struct aat1290_led *led, + unsigned int micro_sec) +{ + struct led_classdev_flash *fled_cdev = &led->fled_cdev; + struct led_flash_setting *flash_tm = &fled_cdev->timeout; + int flash_tm_reg = AAT1290_FLASH_TM_NUM_LEVELS - + (micro_sec / flash_tm->step) + 1; + + aat1290_as2cwire_write(led, AAT1290_FLASH_SAFETY_TIMER_ADDR, + flash_tm_reg); +} + +/* LED subsystem callbacks */ + +static int aat1290_led_brightness_set(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + struct led_classdev_flash *fled_cdev = led_cdev_to_fled_cdev(led_cdev); + struct aat1290_led *led = fled_cdev_to_led(fled_cdev); + + mutex_lock(&led->lock); + + if (brightness == 0) { + gpiod_direction_output(led->gpio_fl_en, 0); + gpiod_direction_output(led->gpio_en_set, 0); + led->movie_mode = false; + } else { + if (!led->movie_mode) { + aat1290_as2cwire_write(led, + AAT1290_MM_CURRENT_RATIO_ADDR, + AAT1290_MM_TO_FL_1_92); + led->movie_mode = true; + } + + aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CURRENT_ADDR, + AAT1290_MAX_MM_CURR_PERCENT_0 - brightness); + aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR, + AAT1290_MOVIE_MODE_ON); + } + + mutex_unlock(&led->lock); + + return 0; +} + +static int aat1290_led_flash_strobe_set(struct led_classdev_flash *fled_cdev, + bool state) + +{ + struct aat1290_led *led = fled_cdev_to_led(fled_cdev); + struct led_classdev *led_cdev = &fled_cdev->led_cdev; + struct led_flash_setting *timeout = &fled_cdev->timeout; + + mutex_lock(&led->lock); + + if (state) { + aat1290_set_flash_safety_timer(led, timeout->val); + gpiod_direction_output(led->gpio_fl_en, 1); + } else { + gpiod_direction_output(led->gpio_fl_en, 0); + gpiod_direction_output(led->gpio_en_set, 0); + } + + /* + * To reenter movie mode after a flash event the part must be cycled + * off and back on to reset the movie mode and reprogrammed via the + * AS2Cwire. Therefore the brightness and movie_mode properties needs + * to be updated here to reflect the actual state. + */ + led_cdev->brightness = 0; + led->movie_mode = false; + + mutex_unlock(&led->lock); + + return 0; +} + +static int aat1290_led_flash_timeout_set(struct led_classdev_flash *fled_cdev, + u32 timeout) +{ + /* + * Don't do anything - flash timeout is cached in the led-class-flash + * core and will be applied in the strobe_set op, as writing the + * safety timer register spuriously turns the torch mode on. + */ + + return 0; +} + +static int aat1290_led_parse_dt(struct aat1290_led *led, + struct aat1290_led_config_data *cfg, + struct device_node **sub_node) +{ + struct device *dev = &led->pdev->dev; + struct device_node *child_node; +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS) + struct pinctrl *pinctrl; +#endif + int ret = 0; + + led->gpio_fl_en = devm_gpiod_get(dev, "flen", GPIOD_ASIS); + if (IS_ERR(led->gpio_fl_en)) { + ret = PTR_ERR(led->gpio_fl_en); + dev_err(dev, "Unable to claim gpio \"flen\".\n"); + return ret; + } + + led->gpio_en_set = devm_gpiod_get(dev, "enset", GPIOD_ASIS); + if (IS_ERR(led->gpio_en_set)) { + ret = PTR_ERR(led->gpio_en_set); + dev_err(dev, "Unable to claim gpio \"enset\".\n"); + return ret; + } + +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS) + pinctrl = devm_pinctrl_get_select_default(&led->pdev->dev); + if (IS_ERR(pinctrl)) { + cfg->has_external_strobe = false; + dev_info(dev, + "No support for external strobe detected.\n"); + } else { + cfg->has_external_strobe = true; + } +#endif + + child_node = of_get_next_available_child(dev_of_node(dev), NULL); + if (!child_node) { + dev_err(dev, "No DT child node found for connected LED.\n"); + return -EINVAL; + } + + ret = of_property_read_u32(child_node, "led-max-microamp", + &cfg->max_mm_current); + /* + * led-max-microamp will default to 1/20 of flash-max-microamp + * in case it is missing. + */ + if (ret < 0) + dev_warn(dev, + "led-max-microamp DT property missing\n"); + + ret = of_property_read_u32(child_node, "flash-max-microamp", + &cfg->max_flash_current); + if (ret < 0) { + dev_err(dev, + "flash-max-microamp DT property missing\n"); + goto err_parse_dt; + } + + ret = of_property_read_u32(child_node, "flash-max-timeout-us", + &cfg->max_flash_tm); + if (ret < 0) { + dev_err(dev, + "flash-max-timeout-us DT property missing\n"); + goto err_parse_dt; + } + + *sub_node = child_node; + +err_parse_dt: + of_node_put(child_node); + + return ret; +} + +static void aat1290_led_validate_mm_current(struct aat1290_led *led, + struct aat1290_led_config_data *cfg) +{ + int i, b = 0, e = AAT1290_MM_CURRENT_SCALE_SIZE; + + while (e - b > 1) { + i = b + (e - b) / 2; + if (cfg->max_mm_current < led->mm_current_scale[i]) + e = i; + else + b = i; + } + + cfg->max_mm_current = led->mm_current_scale[b]; + cfg->max_brightness = b + 1; +} + +static int init_mm_current_scale(struct aat1290_led *led, + struct aat1290_led_config_data *cfg) +{ + static const int max_mm_current_percent[] = { + 20, 22, 25, 28, 32, 36, 40, 45, 50, 56, + 63, 71, 79, 89, 100 + }; + int i, max_mm_current = + AAT1290_MAX_MM_CURRENT(cfg->max_flash_current); + + led->mm_current_scale = devm_kzalloc(&led->pdev->dev, + sizeof(max_mm_current_percent), + GFP_KERNEL); + if (!led->mm_current_scale) + return -ENOMEM; + + for (i = 0; i < AAT1290_MM_CURRENT_SCALE_SIZE; ++i) + led->mm_current_scale[i] = max_mm_current * + max_mm_current_percent[i] / 100; + + return 0; +} + +static int aat1290_led_get_configuration(struct aat1290_led *led, + struct aat1290_led_config_data *cfg, + struct device_node **sub_node) +{ + int ret; + + ret = aat1290_led_parse_dt(led, cfg, sub_node); + if (ret < 0) + return ret; + /* + * Init non-linear movie mode current scale basing + * on the max flash current from led configuration. + */ + ret = init_mm_current_scale(led, cfg); + if (ret < 0) + return ret; + + aat1290_led_validate_mm_current(led, cfg); + +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS) +#else + devm_kfree(&led->pdev->dev, led->mm_current_scale); +#endif + + return 0; +} + +static void aat1290_init_flash_timeout(struct aat1290_led *led, + struct aat1290_led_config_data *cfg) +{ + struct led_classdev_flash *fled_cdev = &led->fled_cdev; + struct led_flash_setting *setting; + + /* Init flash timeout setting */ + setting = &fled_cdev->timeout; + setting->min = cfg->max_flash_tm / AAT1290_FLASH_TM_NUM_LEVELS; + setting->max = cfg->max_flash_tm; + setting->step = setting->min; + setting->val = setting->max; +} + +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS) +static enum led_brightness aat1290_intensity_to_brightness( + struct v4l2_flash *v4l2_flash, + s32 intensity) +{ + struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev; + struct aat1290_led *led = fled_cdev_to_led(fled_cdev); + int i; + + for (i = AAT1290_MM_CURRENT_SCALE_SIZE - 1; i >= 0; --i) + if (intensity >= led->mm_current_scale[i]) + return i + 1; + + return 1; +} + +static s32 aat1290_brightness_to_intensity(struct v4l2_flash *v4l2_flash, + enum led_brightness brightness) +{ + struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev; + struct aat1290_led *led = fled_cdev_to_led(fled_cdev); + + return led->mm_current_scale[brightness - 1]; +} + +static int aat1290_led_external_strobe_set(struct v4l2_flash *v4l2_flash, + bool enable) +{ + struct aat1290_led *led = fled_cdev_to_led(v4l2_flash->fled_cdev); + struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev; + struct led_classdev *led_cdev = &fled_cdev->led_cdev; + struct pinctrl *pinctrl; + + gpiod_direction_output(led->gpio_fl_en, 0); + gpiod_direction_output(led->gpio_en_set, 0); + + led->movie_mode = false; + led_cdev->brightness = 0; + + pinctrl = devm_pinctrl_get_select(&led->pdev->dev, + enable ? "isp" : "host"); + if (IS_ERR(pinctrl)) { + dev_warn(&led->pdev->dev, "Unable to switch strobe source.\n"); + return PTR_ERR(pinctrl); + } + + return 0; +} + +static void aat1290_init_v4l2_flash_config(struct aat1290_led *led, + struct aat1290_led_config_data *led_cfg, + struct v4l2_flash_config *v4l2_sd_cfg) +{ + struct led_classdev *led_cdev = &led->fled_cdev.led_cdev; + struct led_flash_setting *s; + + strlcpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name, + sizeof(v4l2_sd_cfg->dev_name)); + + s = &v4l2_sd_cfg->intensity; + s->min = led->mm_current_scale[0]; + s->max = led_cfg->max_mm_current; + s->step = 1; + s->val = s->max; + + v4l2_sd_cfg->has_external_strobe = led_cfg->has_external_strobe; +} + +static const struct v4l2_flash_ops v4l2_flash_ops = { + .external_strobe_set = aat1290_led_external_strobe_set, + .intensity_to_led_brightness = aat1290_intensity_to_brightness, + .led_brightness_to_intensity = aat1290_brightness_to_intensity, +}; +#else +static inline void aat1290_init_v4l2_flash_config(struct aat1290_led *led, + struct aat1290_led_config_data *led_cfg, + struct v4l2_flash_config *v4l2_sd_cfg) +{ +} +static const struct v4l2_flash_ops v4l2_flash_ops; +#endif + +static const struct led_flash_ops flash_ops = { + .strobe_set = aat1290_led_flash_strobe_set, + .timeout_set = aat1290_led_flash_timeout_set, +}; + +static int aat1290_led_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *sub_node = NULL; + struct aat1290_led *led; + struct led_classdev *led_cdev; + struct led_classdev_flash *fled_cdev; + struct led_init_data init_data = {}; + struct aat1290_led_config_data led_cfg = {}; + struct v4l2_flash_config v4l2_sd_cfg = {}; + int ret; + + led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); + if (!led) + return -ENOMEM; + + led->pdev = pdev; + platform_set_drvdata(pdev, led); + + fled_cdev = &led->fled_cdev; + fled_cdev->ops = &flash_ops; + led_cdev = &fled_cdev->led_cdev; + + ret = aat1290_led_get_configuration(led, &led_cfg, &sub_node); + if (ret < 0) + return ret; + + mutex_init(&led->lock); + + /* Initialize LED Flash class device */ + led_cdev->brightness_set_blocking = aat1290_led_brightness_set; + led_cdev->max_brightness = led_cfg.max_brightness; + led_cdev->flags |= LED_DEV_CAP_FLASH; + + aat1290_init_flash_timeout(led, &led_cfg); + + init_data.fwnode = of_fwnode_handle(sub_node); + init_data.devicename = AAT1290_NAME; + + /* Register LED Flash class device */ + ret = led_classdev_flash_register_ext(&pdev->dev, fled_cdev, + &init_data); + if (ret < 0) + goto err_flash_register; + + aat1290_init_v4l2_flash_config(led, &led_cfg, &v4l2_sd_cfg); + + /* Create V4L2 Flash subdev. */ + led->v4l2_flash = v4l2_flash_init(dev, of_fwnode_handle(sub_node), + fled_cdev, &v4l2_flash_ops, + &v4l2_sd_cfg); + if (IS_ERR(led->v4l2_flash)) { + ret = PTR_ERR(led->v4l2_flash); + goto error_v4l2_flash_init; + } + + return 0; + +error_v4l2_flash_init: + led_classdev_flash_unregister(fled_cdev); +err_flash_register: + mutex_destroy(&led->lock); + + return ret; +} + +static int aat1290_led_remove(struct platform_device *pdev) +{ + struct aat1290_led *led = platform_get_drvdata(pdev); + + v4l2_flash_release(led->v4l2_flash); + led_classdev_flash_unregister(&led->fled_cdev); + + mutex_destroy(&led->lock); + + return 0; +} + +static const struct of_device_id aat1290_led_dt_match[] = { + { .compatible = "skyworks,aat1290" }, + {}, +}; +MODULE_DEVICE_TABLE(of, aat1290_led_dt_match); + +static struct platform_driver aat1290_led_driver = { + .probe = aat1290_led_probe, + .remove = aat1290_led_remove, + .driver = { + .name = "aat1290", + .of_match_table = aat1290_led_dt_match, + }, +}; + +module_platform_driver(aat1290_led_driver); + +MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>"); +MODULE_DESCRIPTION("Skyworks Current Regulator for Flash LEDs"); +MODULE_LICENSE("GPL v2"); |