linux/drivers/leds/leds-lp8501.c
Milo Kim ed13335204 leds:lp55xx: use the private data instead of updating I2C device platform data
Currently, lp55xx_of_populate_pdata() allocates lp55xx_platform_data if
it's null. And it parses the DT and copies values into the
'client->dev.platform_data'. This may have architectural issue.
Platform data is configurable through the DT or I2C board info inside the
platform area. However, lp55xx common driver changes this configuration
when it is loaded. So 'client->dev.platform_data' is not null anymore.
Eventually, the driver initialization is not identical when it's unloaded
and loaded again.
The lp55xx common driver should use the private data, 'lp55xx_chip->pdata'
instead of changing the original platform data.

So, lp55xx_of_populate_pdata() is modified as follows.
* Do not update 'dev->platform_data'. Return the pointer of new allocated
   lp55xx_platform_data. Then the driver points it to private data,
   'lp55xx_chip->pdata'.
* Each lp55xx driver checks the pointer and handles an error case.

Then, original platform data configuration will be kept regardless of
loading or unloading the driver.
The driver allocates the memory and copies them from the DT if it's NULL.
After the driver is loaded again, 'client->dev.platform_data' is same as
initial load, so the driver is initialized identically.

Cc: Toshi Kikuchi <toshik@chromium.org>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
2015-08-28 14:06:28 +02:00

411 lines
9.5 KiB
C

/*
* 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 void lp8501_led_brightness_work(struct work_struct *work)
{
struct lp55xx_led *led = container_of(work, struct lp55xx_led,
brightness_work);
struct lp55xx_chip *chip = led->chip;
mutex_lock(&chip->lock);
lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
led->brightness);
mutex_unlock(&chip->lock);
}
/* 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_work_fn = lp8501_led_brightness_work,
.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");