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kernel/drivers/leds/leds-an30259a.c
Simon Shields 2d00f35c55 leds: add Panasonic AN30259A support 
AN30259A is a 3-channel LED driver which uses I2C. It supports timed
operation via an internal PWM clock, and variable brightness. This
driver offers support for basic hardware-based blinking and brightness
control.

The datasheet is freely available:
https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf

Signed-off-by: Simon Shields <simon@lineageos.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2018-09-10 21:31:11 +02:00

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// SPDX-License-Identifier: GPL-2.0+
//
// Driver for Panasonic AN30259A 3-channel LED driver
//
// Copyright (c) 2018 Simon Shields <simon@lineageos.org>
//
// Datasheet:
// https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <uapi/linux/uleds.h>
#define AN30259A_MAX_LEDS 3
#define AN30259A_REG_SRESET 0x00
#define AN30259A_LED_SRESET BIT(0)
/* LED power registers */
#define AN30259A_REG_LED_ON 0x01
#define AN30259A_LED_EN(x) BIT((x) - 1)
#define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4)
#define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1))
/* slope control registers */
#define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1))
#define AN30259A_LED_SLOPETIME1(x) (x)
#define AN30259A_LED_SLOPETIME2(x) ((x) << 4)
#define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1)))
#define AN30259A_LED_DUTYMAX(x) ((x) << 4)
#define AN30259A_LED_DUTYMID(x) (x)
#define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1)))
#define AN30259A_LED_DELAY(x) ((x) << 4)
#define AN30259A_LED_DUTYMIN(x) (x)
/* detention time control (length of each slope step) */
#define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1)))
#define AN30259A_LED_DT1(x) (x)
#define AN30259A_LED_DT2(x) ((x) << 4)
#define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1)))
#define AN30259A_LED_DT3(x) (x)
#define AN30259A_LED_DT4(x) ((x) << 4)
#define AN30259A_REG_MAX 0x14
#define AN30259A_BLINK_MAX_TIME 7500 /* ms */
#define AN30259A_SLOPE_RESOLUTION 500 /* ms */
#define STATE_OFF 0
#define STATE_KEEP 1
#define STATE_ON 2
struct an30259a;
struct an30259a_led {
struct an30259a *chip;
struct led_classdev cdev;
u32 num;
u32 default_state;
bool sloping;
char label[LED_MAX_NAME_SIZE];
};
struct an30259a {
struct mutex mutex; /* held when writing to registers */
struct i2c_client *client;
struct an30259a_led leds[AN30259A_MAX_LEDS];
struct regmap *regmap;
int num_leds;
};
static int an30259a_brightness_set(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct an30259a_led *led;
int ret;
unsigned int led_on;
led = container_of(cdev, struct an30259a_led, cdev);
mutex_lock(&led->chip->mutex);
ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
if (ret)
goto error;
switch (brightness) {
case LED_OFF:
led_on &= ~AN30259A_LED_EN(led->num);
led_on &= ~AN30259A_LED_SLOPE(led->num);
led->sloping = false;
break;
default:
led_on |= AN30259A_LED_EN(led->num);
if (led->sloping)
led_on |= AN30259A_LED_SLOPE(led->num);
ret = regmap_write(led->chip->regmap,
AN30259A_REG_LEDCNT1(led->num),
AN30259A_LED_DUTYMAX(0xf) |
AN30259A_LED_DUTYMID(0xf));
if (ret)
goto error;
break;
}
ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
if (ret)
goto error;
ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num),
brightness);
error:
mutex_unlock(&led->chip->mutex);
return ret;
}
static int an30259a_blink_set(struct led_classdev *cdev,
unsigned long *delay_off, unsigned long *delay_on)
{
struct an30259a_led *led;
int ret, num;
unsigned int led_on;
unsigned long off = *delay_off, on = *delay_on;
led = container_of(cdev, struct an30259a_led, cdev);
mutex_lock(&led->chip->mutex);
num = led->num;
/* slope time can only be a multiple of 500ms. */
if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) {
ret = -EINVAL;
goto error;
}
/* up to a maximum of 7500ms. */
if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) {
ret = -EINVAL;
goto error;
}
/* if no blink specified, default to 1 Hz. */
if (!off && !on) {
*delay_off = off = 500;
*delay_on = on = 500;
}
/* convert into values the HW will understand. */
off /= AN30259A_SLOPE_RESOLUTION;
on /= AN30259A_SLOPE_RESOLUTION;
/* duty min should be zero (=off), delay should be zero. */
ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num),
AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0));
if (ret)
goto error;
/* reset detention time (no "breathing" effect). */
ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num),
AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0));
if (ret)
goto error;
ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num),
AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0));
if (ret)
goto error;
/* slope time controls on/off cycle length. */
ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num),
AN30259A_LED_SLOPETIME1(off) |
AN30259A_LED_SLOPETIME2(on));
if (ret)
goto error;
/* Finally, enable slope mode. */
ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on);
if (ret)
goto error;
led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num);
ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on);
if (!ret)
led->sloping = true;
error:
mutex_unlock(&led->chip->mutex);
return ret;
}
static int an30259a_dt_init(struct i2c_client *client,
struct an30259a *chip)
{
struct device_node *np = client->dev.of_node, *child;
int count, ret;
int i = 0;
const char *str;
struct an30259a_led *led;
count = of_get_child_count(np);
if (!count || count > AN30259A_MAX_LEDS)
return -EINVAL;
for_each_available_child_of_node(np, child) {
u32 source;
ret = of_property_read_u32(child, "reg", &source);
if (ret != 0 || !source || source > AN30259A_MAX_LEDS) {
dev_err(&client->dev, "Couldn't read LED address: %d\n",
ret);
count--;
continue;
}
led = &chip->leds[i];
led->num = source;
led->chip = chip;
if (of_property_read_string(child, "label", &str))
snprintf(led->label, sizeof(led->label), "an30259a::");
else
snprintf(led->label, sizeof(led->label), "an30259a:%s",
str);
led->cdev.name = led->label;
if (!of_property_read_string(child, "default-state", &str)) {
if (!strcmp(str, "on"))
led->default_state = STATE_ON;
else if (!strcmp(str, "keep"))
led->default_state = STATE_KEEP;
else
led->default_state = STATE_OFF;
}
of_property_read_string(child, "linux,default-trigger",
&led->cdev.default_trigger);
i++;
}
if (!count)
return -EINVAL;
chip->num_leds = i;
return 0;
}
static const struct regmap_config an30259a_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = AN30259A_REG_MAX,
};
static void an30259a_init_default_state(struct an30259a_led *led)
{
struct an30259a *chip = led->chip;
int led_on, err;
switch (led->default_state) {
case STATE_ON:
led->cdev.brightness = LED_FULL;
break;
case STATE_KEEP:
err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on);
if (err)
break;
if (!(led_on & AN30259A_LED_EN(led->num))) {
led->cdev.brightness = LED_OFF;
break;
}
regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num),
&led->cdev.brightness);
break;
default:
led->cdev.brightness = LED_OFF;
}
an30259a_brightness_set(&led->cdev, led->cdev.brightness);
}
static int an30259a_probe(struct i2c_client *client)
{
struct an30259a *chip;
int i, err;
chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
err = an30259a_dt_init(client, chip);
if (err < 0)
return err;
mutex_init(&chip->mutex);
chip->client = client;
i2c_set_clientdata(client, chip);
chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config);
for (i = 0; i < chip->num_leds; i++) {
an30259a_init_default_state(&chip->leds[i]);
chip->leds[i].cdev.brightness_set_blocking =
an30259a_brightness_set;
chip->leds[i].cdev.blink_set = an30259a_blink_set;
err = devm_led_classdev_register(&client->dev,
&chip->leds[i].cdev);
if (err < 0)
goto exit;
}
return 0;
exit:
mutex_destroy(&chip->mutex);
return err;
}
static int an30259a_remove(struct i2c_client *client)
{
struct an30259a *chip = i2c_get_clientdata(client);
mutex_destroy(&chip->mutex);
return 0;
}
static const struct of_device_id an30259a_match_table[] = {
{ .compatible = "panasonic,an30259a", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, an30259a_match_table);
static const struct i2c_device_id an30259a_id[] = {
{ "an30259a", 0 },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(i2c, an30259a_id);
static struct i2c_driver an30259a_driver = {
.driver = {
.name = "leds-an32059a",
.of_match_table = of_match_ptr(an30259a_match_table),
},
.probe_new = an30259a_probe,
.remove = an30259a_remove,
.id_table = an30259a_id,
};
module_i2c_driver(an30259a_driver);
MODULE_AUTHOR("Simon Shields <simon@lineageos.org>");
MODULE_DESCRIPTION("AN32059A LED driver");
MODULE_LICENSE("GPL v2");
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