linux/drivers/leds/leds-lm36274.c

180 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
// TI LM36274 LED chip family driver
// Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/leds.h>
#include <linux/leds-ti-lmu-common.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/mfd/ti-lmu.h>
#include <linux/mfd/ti-lmu-register.h>
#include <uapi/linux/uleds.h>
#define LM36274_MAX_STRINGS 4
#define LM36274_BL_EN BIT(4)
/**
* struct lm36274
* @pdev: platform device
* @led_dev: led class device
* @lmu_data: Register and setting values for common code
* @regmap: Devices register map
* @dev: Pointer to the devices device struct
* @led_sources - The LED strings supported in this array
* @num_leds - Number of LED strings are supported in this array
*/
struct lm36274 {
struct platform_device *pdev;
struct led_classdev led_dev;
struct ti_lmu_bank lmu_data;
struct regmap *regmap;
struct device *dev;
u32 led_sources[LM36274_MAX_STRINGS];
int num_leds;
};
static int lm36274_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brt_val)
{
struct lm36274 *led = container_of(led_cdev, struct lm36274, led_dev);
return ti_lmu_common_set_brightness(&led->lmu_data, brt_val);
}
static int lm36274_init(struct lm36274 *lm36274_data)
{
int enable_val = 0;
int i;
for (i = 0; i < lm36274_data->num_leds; i++)
enable_val |= (1 << lm36274_data->led_sources[i]);
if (!enable_val) {
dev_err(lm36274_data->dev, "No LEDs were enabled\n");
return -EINVAL;
}
enable_val |= LM36274_BL_EN;
return regmap_write(lm36274_data->regmap, LM36274_REG_BL_EN,
enable_val);
}
static int lm36274_parse_dt(struct lm36274 *lm36274_data)
{
struct fwnode_handle *child = NULL;
char label[LED_MAX_NAME_SIZE];
struct device *dev = &lm36274_data->pdev->dev;
const char *name;
int child_cnt;
int ret = -EINVAL;
/* There should only be 1 node */
child_cnt = device_get_child_node_count(dev);
if (child_cnt != 1)
return -EINVAL;
device_for_each_child_node(dev, child) {
ret = fwnode_property_read_string(child, "label", &name);
if (ret)
snprintf(label, sizeof(label),
"%s::", lm36274_data->pdev->name);
else
snprintf(label, sizeof(label),
"%s:%s", lm36274_data->pdev->name, name);
lm36274_data->num_leds = fwnode_property_count_u32(child, "led-sources");
if (lm36274_data->num_leds <= 0)
return -ENODEV;
ret = fwnode_property_read_u32_array(child, "led-sources",
lm36274_data->led_sources,
lm36274_data->num_leds);
if (ret) {
dev_err(dev, "led-sources property missing\n");
return ret;
}
fwnode_property_read_string(child, "linux,default-trigger",
&lm36274_data->led_dev.default_trigger);
}
lm36274_data->lmu_data.regmap = lm36274_data->regmap;
lm36274_data->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT;
lm36274_data->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB;
lm36274_data->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB;
lm36274_data->led_dev.name = label;
lm36274_data->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT;
lm36274_data->led_dev.brightness_set_blocking = lm36274_brightness_set;
return 0;
}
static int lm36274_probe(struct platform_device *pdev)
{
struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent);
struct lm36274 *lm36274_data;
int ret;
lm36274_data = devm_kzalloc(&pdev->dev, sizeof(*lm36274_data),
GFP_KERNEL);
if (!lm36274_data)
return -ENOMEM;
lm36274_data->pdev = pdev;
lm36274_data->dev = lmu->dev;
lm36274_data->regmap = lmu->regmap;
platform_set_drvdata(pdev, lm36274_data);
ret = lm36274_parse_dt(lm36274_data);
if (ret) {
dev_err(lm36274_data->dev, "Failed to parse DT node\n");
return ret;
}
ret = lm36274_init(lm36274_data);
if (ret) {
dev_err(lm36274_data->dev, "Failed to init the device\n");
return ret;
}
return led_classdev_register(lm36274_data->dev, &lm36274_data->led_dev);
}
static int lm36274_remove(struct platform_device *pdev)
{
struct lm36274 *lm36274_data = platform_get_drvdata(pdev);
led_classdev_unregister(&lm36274_data->led_dev);
return 0;
}
static const struct of_device_id of_lm36274_leds_match[] = {
{ .compatible = "ti,lm36274-backlight", },
{},
};
MODULE_DEVICE_TABLE(of, of_lm36274_leds_match);
static struct platform_driver lm36274_driver = {
.probe = lm36274_probe,
.remove = lm36274_remove,
.driver = {
.name = "lm36274-leds",
},
};
module_platform_driver(lm36274_driver)
MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");