Commit 49c34b8e authored by Jacek Anaszewski's avatar Jacek Anaszewski Committed by Bryan Wu

leds: Add driver for AAT1290 flash LED controller

This patch adds a driver for the 1.5A Step-Up Current Regulator
for Flash LEDs. The device is programmed through a Skyworks proprietary
AS2Cwire serial digital interface.
Signed-off-by: default avatarJacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Acked-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarBryan Wu <cooloney@gmail.com>
parent 2269fe09
......@@ -42,6 +42,14 @@ config LEDS_88PM860X
This option enables support for on-chip LED drivers found on Marvell
Semiconductor 88PM8606 PMIC.
config LEDS_AAT1290
tristate "LED support for the AAT1290"
depends on LEDS_CLASS_FLASH
depends on GPIOLIB
depends on OF
help
This option enables support for the LEDs on the AAT1290.
config LEDS_LM3530
tristate "LCD Backlight driver for LM3530"
depends on LEDS_CLASS
......
......@@ -7,6 +7,7 @@ obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o
# LED Platform Drivers
obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o
obj-$(CONFIG_LEDS_AAT1290) += leds-aat1290.o
obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o
obj-$(CONFIG_LEDS_LOCOMO) += leds-locomo.o
obj-$(CONFIG_LEDS_LM3530) += leds-lm3530.o
......
/*
* 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>
*
* 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/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/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.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
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;
/* 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;
/* 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;
/* assures led-triggers compatibility */
struct work_struct work_brightness_set;
};
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 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);
}
static void aat1290_brightness_set(struct aat1290_led *led,
enum led_brightness brightness)
{
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);
}
/* LED subsystem callbacks */
static void aat1290_brightness_set_work(struct work_struct *work)
{
struct aat1290_led *led =
container_of(work, struct aat1290_led, work_brightness_set);
aat1290_brightness_set(led, led->torch_brightness);
}
static void aat1290_led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
struct aat1290_led *led = fled_cdev_to_led(fled_cdev);
led->torch_brightness = brightness;
schedule_work(&led->work_brightness_set);
}
static int aat1290_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 aat1290_led *led = fled_cdev_to_led(fled_cdev);
aat1290_brightness_set(led, brightness);
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 led_classdev *led_cdev = &led->fled_cdev.led_cdev;
struct device *dev = &led->pdev->dev;
struct device_node *child_node;
int ret = 0;
led->gpio_fl_en = devm_gpiod_get(dev, "flen");
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");
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;
}
child_node = of_get_next_available_child(dev->of_node, NULL);
if (!child_node) {
dev_err(dev, "No DT child node found for connected LED.\n");
return -EINVAL;
}
led_cdev->name = of_get_property(child_node, "label", NULL) ? :
child_node->name;
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");
return ret;
}
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");
return ret;
}
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;
}
int init_mm_current_scale(struct aat1290_led *led,
struct aat1290_led_config_data *cfg)
{
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 = kzalloc(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)
{
int ret;
ret = aat1290_led_parse_dt(led, cfg);
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);
kfree(led->mm_current_scale);
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;
}
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 aat1290_led *led;
struct led_classdev *led_cdev;
struct led_classdev_flash *fled_cdev;
struct aat1290_led_config_data led_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);
if (ret < 0)
return ret;
mutex_init(&led->lock);
/* Initialize LED Flash class device */
led_cdev->brightness_set = aat1290_led_brightness_set;
led_cdev->brightness_set_sync = aat1290_led_brightness_set_sync;
led_cdev->max_brightness = led_cfg.max_brightness;
led_cdev->flags |= LED_DEV_CAP_FLASH;
INIT_WORK(&led->work_brightness_set, aat1290_brightness_set_work);
aat1290_init_flash_timeout(led, &led_cfg);
/* Register LED Flash class device */
ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
if (ret < 0)
goto err_flash_register;
return 0;
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);
led_classdev_flash_unregister(&led->fled_cdev);
cancel_work_sync(&led->work_brightness_set);
mutex_destroy(&led->lock);
return 0;
}
static const struct of_device_id aat1290_led_dt_match[] = {
{ .compatible = "skyworks,aat1290" },
{},
};
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");
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