linux/drivers/leds/leds-lp55xx-common.c
Kim, Milo 2dac912809 leds: lp55xx: support dynamic channel settings in the device tree structure
Currently, the LP55xx DT structure supports max 3 channels.
However, LP5523 has max 9 channels and LP5562 has 4 channels.
To enhance this constraint, the DT structure has been changed.

 (a) Use the child node for various channel settings instead of fixed array
 (b) Remove 'num_channel' property.
     This value can be retrieved by counting the children node.
 (c) 'chan-name' property supported
 (d) Documentation updates for LP5521 and LP5523

(cooloney@gmail.com: fix a coding style issue in leds-lp55xx.txt)

Cc: Gabriel Fernandez <gabriel.fernandez@stericsson.com>
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-06-20 16:21:32 -07:00

605 lines
13 KiB
C

/*
* LP5521/LP5523/LP55231/LP5562 Common Driver
*
* Copyright 2012 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.
*
* Derived from leds-lp5521.c, leds-lp5523.c
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_data/leds-lp55xx.h>
#include <linux/slab.h>
#include "leds-lp55xx-common.h"
/* External clock rate */
#define LP55XX_CLK_32K 32768
static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
{
return container_of(cdev, struct lp55xx_led, cdev);
}
static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
{
return cdev_to_lp55xx_led(dev_get_drvdata(dev));
}
static void lp55xx_reset_device(struct lp55xx_chip *chip)
{
struct lp55xx_device_config *cfg = chip->cfg;
u8 addr = cfg->reset.addr;
u8 val = cfg->reset.val;
/* no error checking here because no ACK from the device after reset */
lp55xx_write(chip, addr, val);
}
static int lp55xx_detect_device(struct lp55xx_chip *chip)
{
struct lp55xx_device_config *cfg = chip->cfg;
u8 addr = cfg->enable.addr;
u8 val = cfg->enable.val;
int ret;
ret = lp55xx_write(chip, addr, val);
if (ret)
return ret;
usleep_range(1000, 2000);
ret = lp55xx_read(chip, addr, &val);
if (ret)
return ret;
if (val != cfg->enable.val)
return -ENODEV;
return 0;
}
static int lp55xx_post_init_device(struct lp55xx_chip *chip)
{
struct lp55xx_device_config *cfg = chip->cfg;
if (!cfg->post_init_device)
return 0;
return cfg->post_init_device(chip);
}
static ssize_t lp55xx_show_current(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct lp55xx_led *led = dev_to_lp55xx_led(dev);
return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
}
static ssize_t lp55xx_store_current(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct lp55xx_led *led = dev_to_lp55xx_led(dev);
struct lp55xx_chip *chip = led->chip;
unsigned long curr;
if (kstrtoul(buf, 0, &curr))
return -EINVAL;
if (curr > led->max_current)
return -EINVAL;
if (!chip->cfg->set_led_current)
return len;
mutex_lock(&chip->lock);
chip->cfg->set_led_current(led, (u8)curr);
mutex_unlock(&chip->lock);
return len;
}
static ssize_t lp55xx_show_max_current(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct lp55xx_led *led = dev_to_lp55xx_led(dev);
return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
}
static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
lp55xx_store_current);
static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
static struct attribute *lp55xx_led_attributes[] = {
&dev_attr_led_current.attr,
&dev_attr_max_current.attr,
NULL,
};
static struct attribute_group lp55xx_led_attr_group = {
.attrs = lp55xx_led_attributes
};
static void lp55xx_set_brightness(struct led_classdev *cdev,
enum led_brightness brightness)
{
struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
led->brightness = (u8)brightness;
schedule_work(&led->brightness_work);
}
static int lp55xx_init_led(struct lp55xx_led *led,
struct lp55xx_chip *chip, int chan)
{
struct lp55xx_platform_data *pdata = chip->pdata;
struct lp55xx_device_config *cfg = chip->cfg;
struct device *dev = &chip->cl->dev;
char name[32];
int ret;
int max_channel = cfg->max_channel;
if (chan >= max_channel) {
dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
return -EINVAL;
}
if (pdata->led_config[chan].led_current == 0)
return 0;
led->led_current = pdata->led_config[chan].led_current;
led->max_current = pdata->led_config[chan].max_current;
led->chan_nr = pdata->led_config[chan].chan_nr;
if (led->chan_nr >= max_channel) {
dev_err(dev, "Use channel numbers between 0 and %d\n",
max_channel - 1);
return -EINVAL;
}
led->cdev.brightness_set = lp55xx_set_brightness;
if (pdata->led_config[chan].name) {
led->cdev.name = pdata->led_config[chan].name;
} else {
snprintf(name, sizeof(name), "%s:channel%d",
pdata->label ? : chip->cl->name, chan);
led->cdev.name = name;
}
/*
* register led class device for each channel and
* add device attributes
*/
ret = led_classdev_register(dev, &led->cdev);
if (ret) {
dev_err(dev, "led register err: %d\n", ret);
return ret;
}
ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group);
if (ret) {
dev_err(dev, "led sysfs err: %d\n", ret);
led_classdev_unregister(&led->cdev);
return ret;
}
return 0;
}
static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
{
struct lp55xx_chip *chip = context;
struct device *dev = &chip->cl->dev;
if (!fw) {
dev_err(dev, "firmware request failed\n");
goto out;
}
/* handling firmware data is chip dependent */
mutex_lock(&chip->lock);
chip->fw = fw;
if (chip->cfg->firmware_cb)
chip->cfg->firmware_cb(chip);
mutex_unlock(&chip->lock);
out:
/* firmware should be released for other channel use */
release_firmware(chip->fw);
}
static int lp55xx_request_firmware(struct lp55xx_chip *chip)
{
const char *name = chip->cl->name;
struct device *dev = &chip->cl->dev;
return request_firmware_nowait(THIS_MODULE, true, name, dev,
GFP_KERNEL, chip, lp55xx_firmware_loaded);
}
static ssize_t lp55xx_show_engine_select(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;
return sprintf(buf, "%d\n", chip->engine_idx);
}
static ssize_t lp55xx_store_engine_select(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
unsigned long val;
int ret;
if (kstrtoul(buf, 0, &val))
return -EINVAL;
/* select the engine to be run */
switch (val) {
case LP55XX_ENGINE_1:
case LP55XX_ENGINE_2:
case LP55XX_ENGINE_3:
mutex_lock(&chip->lock);
chip->engine_idx = val;
ret = lp55xx_request_firmware(chip);
mutex_unlock(&chip->lock);
break;
default:
dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
return -EINVAL;
}
if (ret) {
dev_err(dev, "request firmware err: %d\n", ret);
return ret;
}
return len;
}
static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
{
if (chip->cfg->run_engine)
chip->cfg->run_engine(chip, start);
}
static ssize_t lp55xx_store_engine_run(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
struct lp55xx_chip *chip = led->chip;
unsigned long val;
if (kstrtoul(buf, 0, &val))
return -EINVAL;
/* run or stop the selected engine */
if (val <= 0) {
lp55xx_run_engine(chip, false);
return len;
}
mutex_lock(&chip->lock);
lp55xx_run_engine(chip, true);
mutex_unlock(&chip->lock);
return len;
}
static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
lp55xx_show_engine_select, lp55xx_store_engine_select);
static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
static struct attribute *lp55xx_engine_attributes[] = {
&dev_attr_select_engine.attr,
&dev_attr_run_engine.attr,
NULL,
};
static const struct attribute_group lp55xx_engine_attr_group = {
.attrs = lp55xx_engine_attributes,
};
int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
{
return i2c_smbus_write_byte_data(chip->cl, reg, val);
}
EXPORT_SYMBOL_GPL(lp55xx_write);
int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
{
s32 ret;
ret = i2c_smbus_read_byte_data(chip->cl, reg);
if (ret < 0)
return ret;
*val = ret;
return 0;
}
EXPORT_SYMBOL_GPL(lp55xx_read);
int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
{
int ret;
u8 tmp;
ret = lp55xx_read(chip, reg, &tmp);
if (ret)
return ret;
tmp &= ~mask;
tmp |= val & mask;
return lp55xx_write(chip, reg, tmp);
}
EXPORT_SYMBOL_GPL(lp55xx_update_bits);
bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
{
struct clk *clk;
int err;
clk = devm_clk_get(&chip->cl->dev, "32k_clk");
if (IS_ERR(clk))
goto use_internal_clk;
err = clk_prepare_enable(clk);
if (err)
goto use_internal_clk;
if (clk_get_rate(clk) != LP55XX_CLK_32K) {
clk_disable_unprepare(clk);
goto use_internal_clk;
}
dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K);
chip->clk = clk;
return true;
use_internal_clk:
dev_info(&chip->cl->dev, "internal clock used\n");
return false;
}
EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
int lp55xx_init_device(struct lp55xx_chip *chip)
{
struct lp55xx_platform_data *pdata;
struct lp55xx_device_config *cfg;
struct device *dev = &chip->cl->dev;
int ret = 0;
WARN_ON(!chip);
pdata = chip->pdata;
cfg = chip->cfg;
if (!pdata || !cfg)
return -EINVAL;
if (pdata->setup_resources) {
ret = pdata->setup_resources();
if (ret < 0) {
dev_err(dev, "setup resoure err: %d\n", ret);
goto err;
}
}
if (pdata->enable) {
pdata->enable(0);
usleep_range(1000, 2000); /* Keep enable down at least 1ms */
pdata->enable(1);
usleep_range(1000, 2000); /* 500us abs min. */
}
lp55xx_reset_device(chip);
/*
* Exact value is not available. 10 - 20ms
* appears to be enough for reset.
*/
usleep_range(10000, 20000);
ret = lp55xx_detect_device(chip);
if (ret) {
dev_err(dev, "device detection err: %d\n", ret);
goto err;
}
/* chip specific initialization */
ret = lp55xx_post_init_device(chip);
if (ret) {
dev_err(dev, "post init device err: %d\n", ret);
goto err_post_init;
}
return 0;
err_post_init:
lp55xx_deinit_device(chip);
err:
return ret;
}
EXPORT_SYMBOL_GPL(lp55xx_init_device);
void lp55xx_deinit_device(struct lp55xx_chip *chip)
{
struct lp55xx_platform_data *pdata = chip->pdata;
if (chip->clk)
clk_disable_unprepare(chip->clk);
if (pdata->enable)
pdata->enable(0);
if (pdata->release_resources)
pdata->release_resources();
}
EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
{
struct lp55xx_platform_data *pdata = chip->pdata;
struct lp55xx_device_config *cfg = chip->cfg;
int num_channels = pdata->num_channels;
struct lp55xx_led *each;
u8 led_current;
int ret;
int i;
if (!cfg->brightness_work_fn) {
dev_err(&chip->cl->dev, "empty brightness configuration\n");
return -EINVAL;
}
for (i = 0; i < num_channels; i++) {
/* do not initialize channels that are not connected */
if (pdata->led_config[i].led_current == 0)
continue;
led_current = pdata->led_config[i].led_current;
each = led + i;
ret = lp55xx_init_led(each, chip, i);
if (ret)
goto err_init_led;
INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
chip->num_leds++;
each->chip = chip;
/* setting led current at each channel */
if (cfg->set_led_current)
cfg->set_led_current(each, led_current);
}
return 0;
err_init_led:
lp55xx_unregister_leds(led, chip);
return ret;
}
EXPORT_SYMBOL_GPL(lp55xx_register_leds);
void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
{
int i;
struct lp55xx_led *each;
for (i = 0; i < chip->num_leds; i++) {
each = led + i;
led_classdev_unregister(&each->cdev);
flush_work(&each->brightness_work);
}
}
EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
int lp55xx_register_sysfs(struct lp55xx_chip *chip)
{
struct device *dev = &chip->cl->dev;
struct lp55xx_device_config *cfg = chip->cfg;
int ret;
if (!cfg->run_engine || !cfg->firmware_cb)
goto dev_specific_attrs;
ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
if (ret)
return ret;
dev_specific_attrs:
return cfg->dev_attr_group ?
sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
}
EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
{
struct device *dev = &chip->cl->dev;
struct lp55xx_device_config *cfg = chip->cfg;
if (cfg->dev_attr_group)
sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
}
EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
{
struct device_node *child;
struct lp55xx_platform_data *pdata;
struct lp55xx_led_config *cfg;
int num_channels;
int i = 0;
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
num_channels = of_get_child_count(np);
if (num_channels == 0) {
dev_err(dev, "no LED channels\n");
return -EINVAL;
}
cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
if (!cfg)
return -ENOMEM;
pdata->led_config = &cfg[0];
pdata->num_channels = num_channels;
for_each_child_of_node(np, child) {
cfg[i].chan_nr = i;
of_property_read_string(child, "chan-name", &cfg[i].name);
of_property_read_u8(child, "led-cur", &cfg[i].led_current);
of_property_read_u8(child, "max-cur", &cfg[i].max_current);
i++;
}
of_property_read_string(np, "label", &pdata->label);
of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
dev->platform_data = pdata;
return 0;
}
EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
MODULE_DESCRIPTION("LP55xx Common Driver");
MODULE_LICENSE("GPL");