blob: 735647d1e683b4b69e52c7ee9e105229f6a5e4e1 [file] [log] [blame]
/*
* LP5018 LED chip driver.
*
* Copyright (C) 2019 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/slab.h>
#include <linux/platform_data/leds-lp50xx.h>
/* Register Table */
/* LED mode registers (read/write) */
#define LP5018_DEVICE_CONFIG0 0x00
#define LP5018_DEVICE_CONFIG1 0x01
#define LP5018_GLOBAL_DIMMING 0x03
#define LP5018_BRIGHTNESS_BASE 0x07
#define LP5018_COLOR_BASE 0x0F
#define LP5018_MAX_LED_CHANNELS 24
#define NUM_OF_RETRIES 5
struct lp5018_led {
struct i2c_client *client;
const struct lp50xx_platform_data *pdata;
struct attribute **all_attrs;
struct device_attribute *iref_pwm_attrs;
struct attribute_group iref_pwm_attr_group;
const struct lp5018_registers *reg;
};
enum chip_model_t {
LP5018,
};
static const struct lp5018_registers {
const char* model;
const u8 reg_global_dimming;
const u8 reg_pwm_base;
const u8 reg_iref_base;
const int led_channels;
} kModelRegisterMap[] = {
{ "lp5018",
LP5018_GLOBAL_DIMMING,
LP5018_COLOR_BASE,
LP5018_BRIGHTNESS_BASE,
LP5018_MAX_LED_CHANNELS},
};
static const struct lp5018_registers* lp5018_dev_to_register (struct device *dev) {
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
return data->reg;
}
static int lp5018_led_read_byte(struct i2c_client *client, u8 reg, u8 *buf)
{
s32 ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0)
return ret;
*buf = ret;
return 0;
}
static int lp5018_led_write_byte(struct i2c_client *client, u8 reg, u8 val)
{
int ret = i2c_smbus_write_byte_data(client, reg, val);
if (ret < 0) {
dev_err(&client->dev, "%s: failed to write byte data, ret=%d\n",
__func__, ret);
}
return ret;
}
static int lp5018_led_read_block_data(struct i2c_client *client, u8 reg,
u8 len, void *val)
{
int ret = i2c_smbus_read_i2c_block_data(client, reg, len, val);
if (ret == len)
return 0;
dev_err(&client->dev, "%s: failed on block read.\n", __func__);
return -EIO;
}
static int lp5018_led_write_block_data(struct i2c_client *client, u8 reg,
u8 len, const void *val)
{
int ret;
int retry = 0;
// TODO: We should make sure Auto_Incr_EN is enabled
do {
ret = i2c_smbus_write_i2c_block_data(client,
reg, len, val);
if (ret < 0) {
dev_err(&client->dev, "%s: failed on block write. "
"ret=%d, retry=%d\n",
__func__, ret, retry);
}
++retry;
} while (ret == -ERESTARTSYS && retry < NUM_OF_RETRIES);
return ret;
}
static int lp5018_led_reset(struct lp5018_led *data)
{
struct i2c_client *client = data->client;
int reset = data->pdata->reset_gpio;
int ret = gpio_request(reset, "LedRST");
if (ret) {
dev_err(&client->dev, "%s: failed to request GPIO%d.\n",
__func__, reset);
return ret;
}
ret = gpio_direction_output(reset, 1);
if (ret) {
dev_err(&client->dev,
"%s: failed to set gpio to 1.\n", __func__);
gpio_free(reset);
return ret;
}
gpio_set_value(reset, 0);
msleep(1);
gpio_set_value(reset, 1);
gpio_free(reset);
return ret;
}
static int lp5018_led_init(struct lp5018_led *data)
{
struct i2c_client *client = data->client;
int ret, i;
printk("lp5018_led_init\n");
// Toggle enable pin
ret = lp5018_led_reset(data);
if (ret)
dev_err(&client->dev, "%s: failed to reset LED.\n", __func__);
msleep(1);
// Enable driver
// Set Chip_EN
ret = lp5018_led_write_byte(client, LP5018_DEVICE_CONFIG0, 0x40);
// Set Log_Scale_EN, Power_save_EN, Auto_incr_EN and PWm_Dithering_EN
ret = lp5018_led_write_byte(client, LP5018_DEVICE_CONFIG1, 0x3C);
data->reg = &kModelRegisterMap[LP5018];
// Set brightness to 0x80 for all LEDs (default is 0xFF)
for (i = 0; i < 8; ++i) {
ret = lp5018_led_write_byte(client,
data->reg->reg_iref_base + i,
0x80);
if (ret < 0) {
dev_err(&client->dev, "%s: failed to set brightness"
"for led %d to 0x80. ret=%d.\n",
__func__, i, ret);
return ret;
}
}
return 0;
}
/* Helper function to show pwm control values. */
static ssize_t lp5018_led_pwm_show_helper(struct device *dev,
unsigned int led_index, char *buf,
u8 addr)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int ret;
u8 rgb[3];
if (led_index >= data->pdata->num_leds) {
dev_err(dev, "%s: invalid led number: %d\n", __func__,
led_index);
return -EINVAL;
}
addr += data->pdata->start_num[led_index];
ret = lp5018_led_read_block_data(client, addr, sizeof(rgb), rgb);
if (ret) {
dev_err(dev, "%s: failed to read RGB values.\n", __func__);
return -EIO;
}
return scnprintf(buf, PAGE_SIZE, "%hhu %hhu %hhu\n",
rgb[0], rgb[1], rgb[2]);
}
/* Helper function to show iref control values. */
static ssize_t lp5018_led_iref_show_helper(struct device *dev,
unsigned int led_index, char *buf,
u8 addr)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int ret;
u8 brightness;
if (led_index >= data->pdata->num_leds) {
dev_err(dev, "%s: invalid led number: %d\n", __func__,
led_index);
return -EINVAL;
}
addr += led_index;
ret = lp5018_led_read_byte(client, addr, &brightness);
if (ret) {
dev_err(dev, "%s: failed to read brightness.\n", __func__);
return -EIO;
}
return scnprintf(buf, PAGE_SIZE, "%hhu\n", brightness);
}
/* Helper function to store pwm control value to certain LED.
* Input is a char array.
* Format: "255 255 255"
* The input represent R, G, B values from left to right, respectively.
*/
static ssize_t lp5018_led_pwm_store_helper(struct device *dev,
unsigned int led_index,
const char *buf, size_t count, u8 addr)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int ret;
u8 rgb[3];
if (led_index >= data->pdata->num_leds) {
dev_err(dev, "%s: invalid led number: %d\n", __func__,
led_index);
return -EINVAL;
}
ret = sscanf(buf, "%hhu %hhu %hhu", &rgb[0], &rgb[1], &rgb[2]);
if (ret != 3) {
dev_err(dev, "%s: failed to parse rgb values, ret=%d.\n",
__func__, ret);
return -EINVAL;
}
addr += data->pdata->start_num[led_index];
ret = lp5018_led_write_block_data(client, addr, sizeof(rgb), rgb);
if (ret < 0) {
dev_err(dev, "%s: failed to write rgb values to led%d.\n",
__func__, led_index);
return ret;
}
dev_dbg(dev, "%s %s: set led%u(0x%02x): R=%hhu, G=%hhu, B=%hhu\n",
__func__, client->name, led_index, addr,
rgb[0], rgb[1], rgb[2]);
return count;
}
static ssize_t lp5018_led_iref_store_helper(struct device *dev,
unsigned int led_index,
const char *buf, size_t count, u8 addr)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int ret;
u8 brightness;
if (led_index >= data->pdata->num_leds) {
dev_err(dev, "%s: invalid led number: %d\n", __func__,
led_index);
return -EINVAL;
}
ret = sscanf(buf, "%hhu", &brightness);
if (ret != 1) {
dev_err(dev, "%s: failed to parse brightness, ret=%d.\n",
__func__, ret);
return -EINVAL;
}
addr += led_index;
ret = lp5018_led_write_byte(client, addr, brightness);
if (ret < 0) {
dev_err(dev, "%s: failed to write brightness to led%d.\n",
__func__, led_index);
return ret;
}
dev_dbg(dev, "%s %s: set led%u(0x%02x): Val=%hhu\n",
__func__, client->name, led_index, addr,
brightness);
return count;
}
static ssize_t lp5018_led_pwm_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned int led_index;
int ret = sscanf(attr->attr.name, "pwm%u", &led_index);
if (ret != 1) {
dev_err(dev, "%s: failed to get led index.\n", __func__);
return -EINVAL;
}
return lp5018_led_pwm_show_helper(dev, led_index, buf,
lp5018_dev_to_register(dev)->reg_pwm_base);
}
static ssize_t lp5018_led_pwm_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned int led_index;
int ret = sscanf(attr->attr.name, "pwm%u", &led_index);
if (ret != 1) {
dev_err(dev, "%s: failed to get led index.\n", __func__);
return -EINVAL;
}
return lp5018_led_pwm_store_helper(dev, led_index, buf, count,
lp5018_dev_to_register(dev)->reg_pwm_base);
}
/* Function to store pwm control values to specified LEDs.
* Input Format" "LED_Index R G B LED_Index R G B ..."
* Note: All LED indices not specified will have their
* (R,G,B) set to (0, 0 ,0)
* LED indices can be specified in any order
* For example: "0 255 255 255 1 100 150 200" is equivalent
* to "1 100 150 200 0 255 255 255"
*/
static ssize_t lp5018_led_pwm_all_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int num_leds = 0;
int chars_read = 0;
int led_idx;
int ret;
int rgb_start_idx;
u8 rgb[lp5018_dev_to_register(dev)->led_channels];
memset(rgb, 0, sizeof(rgb));
while (sscanf(buf, "%d%n", &led_idx, &chars_read) == 1) {
if (led_idx > data->pdata->num_leds - 1 || led_idx < 0) {
dev_err(dev, "%s: incorrect led index %d supplied\n", __func__, led_idx);
return -EINVAL;
}
++num_leds;
if (num_leds > data->pdata->num_leds) {
dev_err(dev, "%s: incorrect number of leds supplied\n", __func__);
return -EINVAL;
}
buf += chars_read;
rgb_start_idx = data->pdata->start_num[led_idx];
if (sscanf(buf, "%hhu %hhu %hhu%n", &rgb[rgb_start_idx],
&rgb[rgb_start_idx + 1],
&rgb[rgb_start_idx + 2],
&chars_read) != 3) {
dev_err(dev, "%s: unable to parse led values to write\n", __func__);
return -EINVAL;
}
buf += chars_read;
}
ret = lp5018_led_write_block_data(client,
lp5018_dev_to_register(dev)->reg_pwm_base,
sizeof(rgb), rgb);
if (ret < 0) {
dev_err(dev, "%s: failed to write rgb values to all leds, err: %d\n",
__func__, ret);
return ret;
}
return count;
}
static ssize_t lp5018_led_iref_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned int led_index;
int ret = sscanf(attr->attr.name, "iref%u", &led_index);
if (ret != 1) {
dev_err(dev, "%s: failed to get led index.\n", __func__);
return -EINVAL;
}
return lp5018_led_iref_show_helper(dev, led_index, buf,
lp5018_dev_to_register(dev)->reg_iref_base);
}
static ssize_t lp5018_led_iref_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
unsigned int led_index;
int ret = sscanf(attr->attr.name, "iref%u", &led_index);
if (ret != 1) {
dev_err(dev, "%s: failed to get led index.\n", __func__);
return -EINVAL;
}
return lp5018_led_iref_store_helper(dev, led_index, buf, count,
lp5018_dev_to_register(dev)->reg_iref_base);
}
static ssize_t lp5018_led_show_byte_helper(struct device *dev,
char *buf, u8 addr)
{
struct i2c_client *client = to_i2c_client(dev);
u8 read_buf;
int ret = lp5018_led_read_byte(client, addr, &read_buf);
if (ret < 0)
return ret;
return scnprintf(buf, PAGE_SIZE, "%u\n", read_buf);
}
static ssize_t lp5018_led_global_dimming_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return lp5018_led_show_byte_helper(dev, buf,
lp5018_dev_to_register(dev)->reg_global_dimming);
}
static ssize_t lp5018_led_global_dimming_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
int global_dimming;
int ret;
if (kstrtouint(buf, 10, &global_dimming))
return -EINVAL;
/* Do the mask to handle minor input errors without reporting error. */
global_dimming = global_dimming & 0xFF;
ret = lp5018_led_write_byte(client,
lp5018_dev_to_register(dev)->reg_global_dimming,
global_dimming);
if (ret < 0) {
dev_err(dev, "%s: failed to write global_dimming.\n", __func__);
return ret;
}
return count;
}
static ssize_t lp5018_led_init_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct lp5018_led *data = i2c_get_clientdata(client);
int ret;
dev_info(dev, "%s: initializing LED...\n", __func__);
ret = lp5018_led_init(data);
if (ret) {
dev_err(dev, "%s: failed to initialize LED. ret=%d\n",
__func__, ret);
return ret;
}
return count;
}
static DEVICE_ATTR(global_dimming, S_IWUSR | S_IWGRP | S_IRUGO,
lp5018_led_global_dimming_show,
lp5018_led_global_dimming_store);
static DEVICE_ATTR(init_led, S_IWUSR | S_IWGRP, NULL, lp5018_led_init_store);
static DEVICE_ATTR(pwm_all, S_IWUSR | S_IWGRP | S_IRUGO,
NULL, lp5018_led_pwm_all_store);
static struct attribute *other_led_attrs[] = {
&dev_attr_global_dimming.attr,
&dev_attr_init_led.attr,
&dev_attr_pwm_all.attr,
NULL
};
static const struct attribute_group lp5018_led_other_attr_group = {
.attrs = other_led_attrs,
};
#ifdef CONFIG_OF
static struct lp50xx_platform_data *lp5018_led_parse_devtree(
struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device_node *node;
struct lp50xx_platform_data *pdata;
int reset_gpio = -1;
node = dev->of_node;
if (!node) {
dev_err(dev, "%s: of_node is NULL.\n", __func__);
return ERR_PTR(-ENODEV);
}
pdata = devm_kzalloc(dev, sizeof(struct device_node), GFP_KERNEL);
if (!pdata) {
dev_err(dev, "%s: not enough memory left.\n", __func__);
return ERR_PTR(-ENOMEM);
}
if (of_property_read_u32(node, "num_leds", &pdata->num_leds)) {
dev_err(dev, "%s: failed to get number of leds.\n", __func__);
devm_kfree(dev, pdata);
return ERR_PTR(-EINVAL);
}
printk("lp5018 num_leds=%d\n", pdata->num_leds);
if (of_property_read_u32_array(node, "start_num", (u32 *)&pdata->start_num,
pdata->num_leds)) {
dev_err(dev, "%s: failed to get pwm register addresses.\n",
__func__);
devm_kfree(dev, pdata);
return ERR_PTR(-EINVAL);
}
reset_gpio = of_get_named_gpio(node, "reset_gpio", 0);
if (!gpio_is_valid(reset_gpio)) {
dev_err(dev, "%s: failed to get reset_gpio.\n", __func__);
return ERR_PTR(-ENODEV);
}
pdata->reset_gpio = reset_gpio;
return pdata;
}
#endif
static void delete_iref_pwm_attr_array(struct lp5018_led *data, int num_leds)
{
if (data->iref_pwm_attrs) {
int i;
for (i = 0; i < 2 * num_leds ; i++) {
kfree(data->iref_pwm_attrs[i].attr.name);
}
kfree(data->iref_pwm_attrs);
}
kfree(data->all_attrs);
return;
}
static void construct_iref_pwm_device_attributes(struct lp5018_led *data,
int num_leds,
struct kobject *kobj) {
int i, error;
// need to NULL terminate the list of attributes -> add 1
data->all_attrs = kzalloc(sizeof(struct attribute *) * (num_leds * 2 + 1),
GFP_KERNEL);
if (data->all_attrs == NULL)
return;
data->iref_pwm_attrs =
kzalloc(sizeof(struct device_attribute) * num_leds * 2,
GFP_KERNEL);
if (data->iref_pwm_attrs == NULL)
goto fail;
for (i = 0; i < 2 * num_leds; ++i) {
char buf[8];
char* name;
if (i < num_leds)
snprintf(buf, sizeof(buf), "iref%u", i);
else
snprintf(buf, sizeof(buf), "pwm%u", i - num_leds);
name = kzalloc(strlen(buf) + 1, GFP_KERNEL);
if (name == NULL)
goto fail;
strncpy(name, buf, strlen(buf) + 1);
data->iref_pwm_attrs[i].attr.name = name;
data->iref_pwm_attrs[i].attr.mode = S_IWUSR | S_IWGRP | S_IRUGO;
if (i < num_leds) {
data->iref_pwm_attrs[i].show = lp5018_led_iref_show;
data->iref_pwm_attrs[i].store = lp5018_led_iref_store;
} else {
data->iref_pwm_attrs[i].show = lp5018_led_pwm_show;
data->iref_pwm_attrs[i].store = lp5018_led_pwm_store;
}
data->all_attrs[i] = &data->iref_pwm_attrs[i].attr;
}
data->iref_pwm_attr_group.attrs = data->all_attrs;
error = sysfs_create_group(kobj, &data->iref_pwm_attr_group);
if (error)
printk("%s: failed to create sysfs, err:%d\n", __func__, error);
return;
fail:
delete_iref_pwm_attr_array(data, num_leds);
}
static int lp5018_led_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct lp5018_led *data;
struct device *dev = &client->dev;
struct lp50xx_platform_data *pdata = dev_get_platdata(dev);
int error = 0;
if (!pdata) {
pdata = lp5018_led_parse_devtree(client);
if (IS_ERR(pdata)) {
dev_err(dev,
"%s: failed to get device data from device tree.\n",
__func__);
error = -EINVAL;
goto err_get_pdata;
}
}
dev_info(dev, "%s: %s number of leds supported: %d\n", __func__,
client->name, pdata->num_leds);
data = kzalloc(sizeof(struct lp5018_led), GFP_KERNEL);
if (!data) {
dev_err(dev, "%s: failed to allocate memory.\n",
__func__);
error = -ENOMEM;
goto err_free_mem;
}
data->client = client;
data->pdata = pdata;
i2c_set_clientdata(client, data);
error = lp5018_led_init(data);
if (error) {
dev_err(&client->dev, "%s: failed to initialize leds, err:%d\n",
__func__, error);
goto err_free_mem;
}
construct_iref_pwm_device_attributes(data, pdata->num_leds,
&client->dev.kobj);
error = sysfs_create_group(&client->dev.kobj,
&lp5018_led_other_attr_group);
if (error) {
dev_err(&client->dev, "%s: failed to create sysfs, err:%d\n",
__func__, error);
goto err_free_sysfs;
}
dev_info(dev, "%s: %s probe successfully!\n", __func__, client->name);
return 0;
err_free_sysfs:
delete_iref_pwm_attr_array(data, pdata->num_leds);
err_free_mem:
kfree(data);
err_get_pdata:
return error;
}
static int lp5018_led_remove(struct i2c_client *client)
{
/* There is no power-off for the product so probably i2c driver/device
* unbinding is not called. Leave this function here for driver
* integrity but return 0 directly.
* */
return 0;
}
static void lp5018_led_shutdown(struct i2c_client *client)
{
struct lp5018_led *data = i2c_get_clientdata(client);
int num_leds = data->pdata->num_leds;
int ret;
dev_info(&client->dev, "%s: prepare to shutdown device.\n", __func__);
ret = lp5018_led_reset(data);
if (ret)
dev_err(&client->dev, "%s: failed to reset LED.\n", __func__);
sysfs_remove_group(&client->dev.kobj, &data->iref_pwm_attr_group);
sysfs_remove_group(&client->dev.kobj, &lp5018_led_other_attr_group);
delete_iref_pwm_attr_array(data, num_leds);
kfree(data);
}
static const struct i2c_device_id lp5018_led_id[] = {
{ "led-lp5108", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, lp5018_led_id);
#ifdef CONFIG_OF
static const struct of_device_id lp5018_led_of_match[] = {
{ .compatible = "ti,led-lp5018" },
{ }
};
#endif
static struct i2c_driver lp5018_led_driver = {
.driver = {
.name = "lp5018-leds",
.owner = THIS_MODULE,
.pm = NULL,
.of_match_table = of_match_ptr(lp5018_led_of_match),
},
.probe = lp5018_led_probe,
.remove = lp5018_led_remove,
.shutdown = lp5018_led_shutdown,
.id_table = lp5018_led_id,
};
module_i2c_driver(lp5018_led_driver);
MODULE_AUTHOR("Blake Jacquot <blakejacquot@google.com>");
MODULE_DESCRIPTION("TI LP5018 LED driver");
MODULE_LICENSE("GPL");