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alistair23-linux/drivers/leds/leds-ktd2692.c
Uwe Kleine-König 5e324ebf01 leds: ktd2692: pass flags parameter to devm_gpiod_get 
Since 39b2bbe3d7 (gpio: add flags argument to gpiod_get*() functions)
which appeared in v3.17-rc1, the gpiod_get* functions take an additional
parameter that allows to specify direction and initial value for output.

In this case the driver cannot easily be simplified but as the flags
parameter will become mandatory soon this change is necessary
beforehand.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2015-06-22 13:57:16 -07:00

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/*
* 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", GPIOD_ASIS);
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", GPIOD_ASIS);
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");
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