linux/drivers/leds/leds-lp8501.c

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/*
* TI LP8501 9 channel LED Driver
*
* Copyright (C) 2013 Texas Instruments
*
* Author: Milo(Woogyom) Kim <milo.kim@ti.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/firmware.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_data/leds-lp55xx.h>
#include <linux/slab.h>
#include "leds-lp55xx-common.h"
#define LP8501_PROGRAM_LENGTH 32
#define LP8501_MAX_LEDS 9
/* Registers */
#define LP8501_REG_ENABLE 0x00
#define LP8501_ENABLE BIT(6)
#define LP8501_EXEC_M 0x3F
#define LP8501_EXEC_ENG1_M 0x30
#define LP8501_EXEC_ENG2_M 0x0C
#define LP8501_EXEC_ENG3_M 0x03
#define LP8501_RUN_ENG1 0x20
#define LP8501_RUN_ENG2 0x08
#define LP8501_RUN_ENG3 0x02
#define LP8501_REG_OP_MODE 0x01
#define LP8501_MODE_ENG1_M 0x30
#define LP8501_MODE_ENG2_M 0x0C
#define LP8501_MODE_ENG3_M 0x03
#define LP8501_LOAD_ENG1 0x10
#define LP8501_LOAD_ENG2 0x04
#define LP8501_LOAD_ENG3 0x01
#define LP8501_REG_PWR_CONFIG 0x05
#define LP8501_PWR_CONFIG_M 0x03
#define LP8501_REG_LED_PWM_BASE 0x16
#define LP8501_REG_LED_CURRENT_BASE 0x26
#define LP8501_REG_CONFIG 0x36
#define LP8501_PWM_PSAVE BIT(7)
#define LP8501_AUTO_INC BIT(6)
#define LP8501_PWR_SAVE BIT(5)
#define LP8501_CP_AUTO 0x18
#define LP8501_INT_CLK BIT(0)
#define LP8501_DEFAULT_CFG \
(LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO)
#define LP8501_REG_RESET 0x3D
#define LP8501_RESET 0xFF
#define LP8501_REG_PROG_PAGE_SEL 0x4F
#define LP8501_PAGE_ENG1 0
#define LP8501_PAGE_ENG2 1
#define LP8501_PAGE_ENG3 2
#define LP8501_REG_PROG_MEM 0x50
#define LP8501_ENG1_IS_LOADING(mode) \
((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1)
#define LP8501_ENG2_IS_LOADING(mode) \
((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2)
#define LP8501_ENG3_IS_LOADING(mode) \
((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3)
static inline void lp8501_wait_opmode_done(void)
{
usleep_range(1000, 2000);
}
static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
{
led->led_current = led_current;
lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
led_current);
}
static int lp8501_post_init_device(struct lp55xx_chip *chip)
{
int ret;
u8 val = LP8501_DEFAULT_CFG;
ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE);
if (ret)
return ret;
/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
usleep_range(1000, 2000);
if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT)
val |= LP8501_INT_CLK;
ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
if (ret)
return ret;
/* Power selection for each output */
return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
}
static void lp8501_load_engine(struct lp55xx_chip *chip)
{
enum lp55xx_engine_index idx = chip->engine_idx;
u8 mask[] = {
[LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
[LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
[LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
};
u8 val[] = {
[LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
[LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
[LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
};
u8 page_sel[] = {
[LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
[LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
[LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
};
lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
lp8501_wait_opmode_done();
lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
}
static void lp8501_stop_engine(struct lp55xx_chip *chip)
{
lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
lp8501_wait_opmode_done();
}
static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
{
int i;
for (i = 0; i < LP8501_MAX_LEDS; i++)
lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
}
static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
{
int ret;
u8 mode;
u8 exec;
/* stop engine */
if (!start) {
lp8501_stop_engine(chip);
lp8501_turn_off_channels(chip);
return;
}
/*
* To run the engine,
* operation mode and enable register should updated at the same time
*/
ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
if (ret)
return;
ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
if (ret)
return;
/* change operation mode to RUN only when each engine is loading */
if (LP8501_ENG1_IS_LOADING(mode)) {
mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
}
if (LP8501_ENG2_IS_LOADING(mode)) {
mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
}
if (LP8501_ENG3_IS_LOADING(mode)) {
mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
}
lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
lp8501_wait_opmode_done();
lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
}
static int lp8501_update_program_memory(struct lp55xx_chip *chip,
const u8 *data, size_t size)
{
u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
unsigned cmd;
char c[3];
int update_size;
int nrchars;
int offset = 0;
int ret;
int i;
/* clear program memory before updating */
for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
i = 0;
while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
/* separate sscanfs because length is working only for %s */
ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
if (ret != 1)
goto err;
ret = sscanf(c, "%2x", &cmd);
if (ret != 1)
goto err;
pattern[i] = (u8)cmd;
offset += nrchars;
i++;
}
/* Each instruction is 16bit long. Check that length is even */
if (i % 2)
goto err;
update_size = i;
for (i = 0; i < update_size; i++)
lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
return 0;
err:
dev_err(&chip->cl->dev, "wrong pattern format\n");
return -EINVAL;
}
static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
{
const struct firmware *fw = chip->fw;
if (fw->size > LP8501_PROGRAM_LENGTH) {
dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
fw->size);
return;
}
/*
* Program memory sequence
* 1) set engine mode to "LOAD"
* 2) write firmware data into program memory
*/
lp8501_load_engine(chip);
lp8501_update_program_memory(chip, fw->data, fw->size);
}
static int lp8501_led_brightness(struct lp55xx_led *led)
{
struct lp55xx_chip *chip = led->chip;
int ret;
mutex_lock(&chip->lock);
ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
led->brightness);
mutex_unlock(&chip->lock);
return ret;
}
/* Chip specific configurations */
static struct lp55xx_device_config lp8501_cfg = {
.reset = {
.addr = LP8501_REG_RESET,
.val = LP8501_RESET,
},
.enable = {
.addr = LP8501_REG_ENABLE,
.val = LP8501_ENABLE,
},
.max_channel = LP8501_MAX_LEDS,
.post_init_device = lp8501_post_init_device,
.brightness_fn = lp8501_led_brightness,
.set_led_current = lp8501_set_led_current,
.firmware_cb = lp8501_firmware_loaded,
.run_engine = lp8501_run_engine,
};
static int lp8501_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct lp55xx_chip *chip;
struct lp55xx_led *led;
struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
struct device_node *np = client->dev.of_node;
if (!pdata) {
if (np) {
pdata = lp55xx_of_populate_pdata(&client->dev, np);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
} else {
dev_err(&client->dev, "no platform data\n");
return -EINVAL;
}
}
chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
led = devm_kzalloc(&client->dev,
sizeof(*led) * pdata->num_channels, GFP_KERNEL);
if (!led)
return -ENOMEM;
chip->cl = client;
chip->pdata = pdata;
chip->cfg = &lp8501_cfg;
mutex_init(&chip->lock);
i2c_set_clientdata(client, led);
ret = lp55xx_init_device(chip);
if (ret)
goto err_init;
dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
ret = lp55xx_register_leds(led, chip);
if (ret)
goto err_register_leds;
ret = lp55xx_register_sysfs(chip);
if (ret) {
dev_err(&client->dev, "registering sysfs failed\n");
goto err_register_sysfs;
}
return 0;
err_register_sysfs:
lp55xx_unregister_leds(led, chip);
err_register_leds:
lp55xx_deinit_device(chip);
err_init:
return ret;
}
static int lp8501_remove(struct i2c_client *client)
{
struct lp55xx_led *led = i2c_get_clientdata(client);
struct lp55xx_chip *chip = led->chip;
lp8501_stop_engine(chip);
lp55xx_unregister_sysfs(chip);
lp55xx_unregister_leds(led, chip);
lp55xx_deinit_device(chip);
return 0;
}
static const struct i2c_device_id lp8501_id[] = {
{ "lp8501", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lp8501_id);
#ifdef CONFIG_OF
static const struct of_device_id of_lp8501_leds_match[] = {
{ .compatible = "ti,lp8501", },
{},
};
MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
#endif
static struct i2c_driver lp8501_driver = {
.driver = {
.name = "lp8501",
.of_match_table = of_match_ptr(of_lp8501_leds_match),
},
.probe = lp8501_probe,
.remove = lp8501_remove,
.id_table = lp8501_id,
};
module_i2c_driver(lp8501_driver);
MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");