// 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");