diff options
Diffstat (limited to 'drivers/leds/leds-lm36274.c')
| -rw-r--r-- | drivers/leds/leds-lm36274.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/leds/leds-lm36274.c b/drivers/leds/leds-lm36274.c new file mode 100644 index 000000000..e009b6d17 --- /dev/null +++ b/drivers/leds/leds-lm36274.c @@ -0,0 +1,172 @@ +// 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/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.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 *chip = container_of(led_cdev, struct lm36274, led_dev); + + return ti_lmu_common_set_brightness(&chip->lmu_data, brt_val); +} + +static int lm36274_init(struct lm36274 *chip) +{ + int enable_val = 0; + int i; + + for (i = 0; i < chip->num_leds; i++) + enable_val |= (1 << chip->led_sources[i]); + + if (!enable_val) { + dev_err(chip->dev, "No LEDs were enabled\n"); + return -EINVAL; + } + + enable_val |= LM36274_BL_EN; + + return regmap_write(chip->regmap, LM36274_REG_BL_EN, enable_val); +} + +static int lm36274_parse_dt(struct lm36274 *chip, + struct led_init_data *init_data) +{ + struct device *dev = chip->dev; + struct fwnode_handle *child; + int ret; + + /* There should only be 1 node */ + if (device_get_child_node_count(dev) != 1) + return -EINVAL; + + child = device_get_next_child_node(dev, NULL); + + init_data->fwnode = child; + init_data->devicename = chip->pdev->name; + /* for backwards compatibility when `label` property is not present */ + init_data->default_label = ":"; + + chip->num_leds = fwnode_property_count_u32(child, "led-sources"); + if (chip->num_leds <= 0) { + ret = -ENODEV; + goto err; + } + + ret = fwnode_property_read_u32_array(child, "led-sources", + chip->led_sources, chip->num_leds); + if (ret) { + dev_err(dev, "led-sources property missing\n"); + goto err; + } + + return 0; +err: + fwnode_handle_put(child); + return ret; +} + +static int lm36274_probe(struct platform_device *pdev) +{ + struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent); + struct led_init_data init_data = {}; + struct lm36274 *chip; + int ret; + + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->pdev = pdev; + chip->dev = &pdev->dev; + chip->regmap = lmu->regmap; + platform_set_drvdata(pdev, chip); + + ret = lm36274_parse_dt(chip, &init_data); + if (ret) { + dev_err(chip->dev, "Failed to parse DT node\n"); + return ret; + } + + ret = lm36274_init(chip); + if (ret) { + fwnode_handle_put(init_data.fwnode); + dev_err(chip->dev, "Failed to init the device\n"); + return ret; + } + + chip->lmu_data.regmap = chip->regmap; + chip->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT; + chip->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB; + chip->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB; + + chip->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT; + chip->led_dev.brightness_set_blocking = lm36274_brightness_set; + + ret = devm_led_classdev_register_ext(chip->dev, &chip->led_dev, + &init_data); + if (ret) + dev_err(chip->dev, "Failed to register LED for node %pfw\n", + init_data.fwnode); + + fwnode_handle_put(init_data.fwnode); + + return ret; +} + +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, + .driver = { + .name = "lm36274-leds", + .of_match_table = of_lm36274_leds_match, + }, +}; +module_platform_driver(lm36274_driver) + +MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver"); +MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); +MODULE_LICENSE("GPL v2"); |