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linux/drivers/leds/leds-lp5521.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

617 lines
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/*
* LP5521 LED chip driver.
*
* Copyright (C) 2010 Nokia Corporation
* Copyright (C) 2012 Texas Instruments
*
* Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_data/leds-lp55xx.h>
#include <linux/slab.h>
#include <linux/of.h>
#include "leds-lp55xx-common.h"
#define LP5521_PROGRAM_LENGTH 32
#define LP5521_MAX_LEDS 3
#define LP5521_CMD_DIRECT 0x3F
/* Registers */
#define LP5521_REG_ENABLE 0x00
#define LP5521_REG_OP_MODE 0x01
#define LP5521_REG_R_PWM 0x02
#define LP5521_REG_G_PWM 0x03
#define LP5521_REG_B_PWM 0x04
#define LP5521_REG_R_CURRENT 0x05
#define LP5521_REG_G_CURRENT 0x06
#define LP5521_REG_B_CURRENT 0x07
#define LP5521_REG_CONFIG 0x08
#define LP5521_REG_STATUS 0x0C
#define LP5521_REG_RESET 0x0D
#define LP5521_REG_R_PROG_MEM 0x10
#define LP5521_REG_G_PROG_MEM 0x30
#define LP5521_REG_B_PROG_MEM 0x50
/* Base register to set LED current */
#define LP5521_REG_LED_CURRENT_BASE LP5521_REG_R_CURRENT
/* Base register to set the brightness */
#define LP5521_REG_LED_PWM_BASE LP5521_REG_R_PWM
/* Bits in ENABLE register */
#define LP5521_MASTER_ENABLE 0x40 /* Chip master enable */
#define LP5521_LOGARITHMIC_PWM 0x80 /* Logarithmic PWM adjustment */
#define LP5521_EXEC_RUN 0x2A
#define LP5521_ENABLE_DEFAULT \
(LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
#define LP5521_ENABLE_RUN_PROGRAM \
(LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
/* CONFIG register */
#define LP5521_PWM_HF 0x40 /* PWM: 0 = 256Hz, 1 = 558Hz */
#define LP5521_PWRSAVE_EN 0x20 /* 1 = Power save mode */
#define LP5521_CP_MODE_OFF 0 /* Charge pump (CP) off */
#define LP5521_CP_MODE_BYPASS 8 /* CP forced to bypass mode */
#define LP5521_CP_MODE_1X5 0x10 /* CP forced to 1.5x mode */
#define LP5521_CP_MODE_AUTO 0x18 /* Automatic mode selection */
#define LP5521_R_TO_BATT 0x04 /* R out: 0 = CP, 1 = Vbat */
#define LP5521_CLK_INT 0x01 /* Internal clock */
#define LP5521_DEFAULT_CFG \
(LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO)
/* Status */
#define LP5521_EXT_CLK_USED 0x08
/* default R channel current register value */
#define LP5521_REG_R_CURR_DEFAULT 0xAF
/* Reset register value */
#define LP5521_RESET 0xFF
/* Program Memory Operations */
#define LP5521_MODE_R_M 0x30 /* Operation Mode Register */
#define LP5521_MODE_G_M 0x0C
#define LP5521_MODE_B_M 0x03
#define LP5521_LOAD_R 0x10
#define LP5521_LOAD_G 0x04
#define LP5521_LOAD_B 0x01
#define LP5521_R_IS_LOADING(mode) \
((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
#define LP5521_G_IS_LOADING(mode) \
((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
#define LP5521_B_IS_LOADING(mode) \
((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
#define LP5521_EXEC_R_M 0x30 /* Enable Register */
#define LP5521_EXEC_G_M 0x0C
#define LP5521_EXEC_B_M 0x03
#define LP5521_EXEC_M 0x3F
#define LP5521_RUN_R 0x20
#define LP5521_RUN_G 0x08
#define LP5521_RUN_B 0x02
static inline void lp5521_wait_opmode_done(void)
{
/* operation mode change needs to be longer than 153 us */
usleep_range(200, 300);
}
static inline void lp5521_wait_enable_done(void)
{
/* it takes more 488 us to update ENABLE register */
usleep_range(500, 600);
}
static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
{
led->led_current = led_current;
lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
led_current);
}
static void lp5521_load_engine(struct lp55xx_chip *chip)
{
enum lp55xx_engine_index idx = chip->engine_idx;
u8 mask[] = {
[LP55XX_ENGINE_1] = LP5521_MODE_R_M,
[LP55XX_ENGINE_2] = LP5521_MODE_G_M,
[LP55XX_ENGINE_3] = LP5521_MODE_B_M,
};
u8 val[] = {
[LP55XX_ENGINE_1] = LP5521_LOAD_R,
[LP55XX_ENGINE_2] = LP5521_LOAD_G,
[LP55XX_ENGINE_3] = LP5521_LOAD_B,
};
lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
lp5521_wait_opmode_done();
}
static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
{
lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
lp5521_wait_opmode_done();
}
static void lp5521_stop_engine(struct lp55xx_chip *chip)
{
enum lp55xx_engine_index idx = chip->engine_idx;
u8 mask[] = {
[LP55XX_ENGINE_1] = LP5521_MODE_R_M,
[LP55XX_ENGINE_2] = LP5521_MODE_G_M,
[LP55XX_ENGINE_3] = LP5521_MODE_B_M,
};
lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], 0);
lp5521_wait_opmode_done();
}
static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
{
int ret;
u8 mode;
u8 exec;
/* stop engine */
if (!start) {
lp5521_stop_engine(chip);
lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
lp5521_wait_opmode_done();
return;
}
/*
* To run the engine,
* operation mode and enable register should updated at the same time
*/
ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
if (ret)
return;
ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
if (ret)
return;
/* change operation mode to RUN only when each engine is loading */
if (LP5521_R_IS_LOADING(mode)) {
mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
}
if (LP5521_G_IS_LOADING(mode)) {
mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
}
if (LP5521_B_IS_LOADING(mode)) {
mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
}
lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
lp5521_wait_opmode_done();
lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
lp5521_wait_enable_done();
}
static int lp5521_update_program_memory(struct lp55xx_chip *chip,
const u8 *data, size_t size)
{
enum lp55xx_engine_index idx = chip->engine_idx;
u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
u8 addr[] = {
[LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
[LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
[LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
};
unsigned cmd;
char c[3];
int nrchars;
int ret;
int offset = 0;
int i = 0;
while ((offset < size - 1) && (i < LP5521_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;
for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
if (ret)
return -EINVAL;
}
return size;
err:
dev_err(&chip->cl->dev, "wrong pattern format\n");
return -EINVAL;
}
static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
{
const struct firmware *fw = chip->fw;
if (fw->size > LP5521_PROGRAM_LENGTH) {
dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
fw->size);
return;
}
/*
* Program momery sequence
* 1) set engine mode to "LOAD"
* 2) write firmware data into program memory
*/
lp5521_load_engine(chip);
lp5521_update_program_memory(chip, fw->data, fw->size);
}
static int lp5521_post_init_device(struct lp55xx_chip *chip)
{
int ret;
u8 val;
/*
* Make sure that the chip is reset by reading back the r channel
* current reg. This is dummy read is required on some platforms -
* otherwise further access to the R G B channels in the
* LP5521_REG_ENABLE register will not have any effect - strange!
*/
ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
if (ret) {
dev_err(&chip->cl->dev, "error in resetting chip\n");
return ret;
}
if (val != LP5521_REG_R_CURR_DEFAULT) {
dev_err(&chip->cl->dev,
"unexpected data in register (expected 0x%x got 0x%x)\n",
LP5521_REG_R_CURR_DEFAULT, val);
ret = -EINVAL;
return ret;
}
usleep_range(10000, 20000);
/* Set all PWMs to direct control mode */
ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
/* Update configuration for the clock setting */
val = LP5521_DEFAULT_CFG;
if (!lp55xx_is_extclk_used(chip))
val |= LP5521_CLK_INT;
ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
if (ret)
return ret;
/* Initialize all channels PWM to zero -> leds off */
lp55xx_write(chip, LP5521_REG_R_PWM, 0);
lp55xx_write(chip, LP5521_REG_G_PWM, 0);
lp55xx_write(chip, LP5521_REG_B_PWM, 0);
/* Set engines are set to run state when OP_MODE enables engines */
ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
if (ret)
return ret;
lp5521_wait_enable_done();
return 0;
}
static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
{
struct lp55xx_platform_data *pdata = chip->pdata;
int ret;
u8 status;
ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
if (ret < 0)
return ret;
if (pdata->clock_mode != LP55XX_CLOCK_EXT)
return 0;
/* Check that ext clock is really in use if requested */
if ((status & LP5521_EXT_CLK_USED) == 0)
return -EIO;
return 0;
}
static void lp5521_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, LP5521_REG_LED_PWM_BASE + led->chan_nr,
led->brightness);
mutex_unlock(&chip->lock);
}
static ssize_t show_engine_mode(struct device *dev,
struct device_attribute *attr,
char *buf, int nr)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
switch (mode) {
case LP55XX_ENGINE_RUN:
return sprintf(buf, "run\n");
case LP55XX_ENGINE_LOAD:
return sprintf(buf, "load\n");
case LP55XX_ENGINE_DISABLED:
default:
return sprintf(buf, "disabled\n");
}
}
show_mode(1)
show_mode(2)
show_mode(3)
static ssize_t store_engine_mode(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len, int nr)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
struct lp55xx_engine *engine = &chip->engines[nr - 1];
mutex_lock(&chip->lock);
chip->engine_idx = nr;
if (!strncmp(buf, "run", 3)) {
lp5521_run_engine(chip, true);
engine->mode = LP55XX_ENGINE_RUN;
} else if (!strncmp(buf, "load", 4)) {
lp5521_stop_engine(chip);
lp5521_load_engine(chip);
engine->mode = LP55XX_ENGINE_LOAD;
} else if (!strncmp(buf, "disabled", 8)) {
lp5521_stop_engine(chip);
engine->mode = LP55XX_ENGINE_DISABLED;
}
mutex_unlock(&chip->lock);
return len;
}
store_mode(1)
store_mode(2)
store_mode(3)
static ssize_t store_engine_load(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len, int nr)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
int ret;
mutex_lock(&chip->lock);
chip->engine_idx = nr;
lp5521_load_engine(chip);
ret = lp5521_update_program_memory(chip, buf, len);
mutex_unlock(&chip->lock);
return ret;
}
store_load(1)
store_load(2)
store_load(3)
static ssize_t lp5521_selftest(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
int ret;
mutex_lock(&chip->lock);
ret = lp5521_run_selftest(chip, buf);
mutex_unlock(&chip->lock);
return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
}
/* device attributes */
static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
static struct attribute *lp5521_attributes[] = {
&dev_attr_engine1_mode.attr,
&dev_attr_engine2_mode.attr,
&dev_attr_engine3_mode.attr,
&dev_attr_engine1_load.attr,
&dev_attr_engine2_load.attr,
&dev_attr_engine3_load.attr,
&dev_attr_selftest.attr,
NULL
};
static const struct attribute_group lp5521_group = {
.attrs = lp5521_attributes,
};
/* Chip specific configurations */
static struct lp55xx_device_config lp5521_cfg = {
.reset = {
.addr = LP5521_REG_RESET,
.val = LP5521_RESET,
},
.enable = {
.addr = LP5521_REG_ENABLE,
.val = LP5521_ENABLE_DEFAULT,
},
.max_channel = LP5521_MAX_LEDS,
.post_init_device = lp5521_post_init_device,
.brightness_work_fn = lp5521_led_brightness_work,
.set_led_current = lp5521_set_led_current,
.firmware_cb = lp5521_firmware_loaded,
.run_engine = lp5521_run_engine,
.dev_attr_group = &lp5521_group,
};
static int lp5521_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 = &lp5521_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 lp5521_remove(struct i2c_client *client)
{
struct lp55xx_led *led = i2c_get_clientdata(client);
struct lp55xx_chip *chip = led->chip;
lp5521_stop_all_engines(chip);
lp55xx_unregister_sysfs(chip);
lp55xx_unregister_leds(led, chip);
lp55xx_deinit_device(chip);
return 0;
}
static const struct i2c_device_id lp5521_id[] = {
{ "lp5521", 0 }, /* Three channel chip */
{ }
};
MODULE_DEVICE_TABLE(i2c, lp5521_id);
#ifdef CONFIG_OF
static const struct of_device_id of_lp5521_leds_match[] = {
{ .compatible = "national,lp5521", },
{},
};
MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
#endif
static struct i2c_driver lp5521_driver = {
.driver = {
.name = "lp5521",
.of_match_table = of_match_ptr(of_lp5521_leds_match),
},
.probe = lp5521_probe,
.remove = lp5521_remove,
.id_table = lp5521_id,
};
module_i2c_driver(lp5521_driver);
MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
MODULE_DESCRIPTION("LP5521 LED engine");
MODULE_LICENSE("GPL v2");
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