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1// SPDX-License-Identifier: GPL-2.02// TI LM36274 LED chip family driver3// Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/4 5#include <linux/bitops.h>6#include <linux/device.h>7#include <linux/err.h>8#include <linux/leds.h>9#include <linux/leds-ti-lmu-common.h>10#include <linux/mod_devicetable.h>11#include <linux/module.h>12#include <linux/platform_device.h>13#include <linux/property.h>14 15#include <linux/mfd/ti-lmu.h>16#include <linux/mfd/ti-lmu-register.h>17 18#include <uapi/linux/uleds.h>19 20#define LM36274_MAX_STRINGS 421#define LM36274_BL_EN BIT(4)22 23/**24 * struct lm3627425 * @pdev: platform device26 * @led_dev: led class device27 * @lmu_data: Register and setting values for common code28 * @regmap: Devices register map29 * @dev: Pointer to the devices device struct30 * @led_sources: The LED strings supported in this array31 * @num_leds: Number of LED strings are supported in this array32 */33struct lm36274 {34 struct platform_device *pdev;35 struct led_classdev led_dev;36 struct ti_lmu_bank lmu_data;37 struct regmap *regmap;38 struct device *dev;39 40 u32 led_sources[LM36274_MAX_STRINGS];41 int num_leds;42};43 44static int lm36274_brightness_set(struct led_classdev *led_cdev,45 enum led_brightness brt_val)46{47 struct lm36274 *chip = container_of(led_cdev, struct lm36274, led_dev);48 49 return ti_lmu_common_set_brightness(&chip->lmu_data, brt_val);50}51 52static int lm36274_init(struct lm36274 *chip)53{54 int enable_val = 0;55 int i;56 57 for (i = 0; i < chip->num_leds; i++)58 enable_val |= (1 << chip->led_sources[i]);59 60 if (!enable_val) {61 dev_err(chip->dev, "No LEDs were enabled\n");62 return -EINVAL;63 }64 65 enable_val |= LM36274_BL_EN;66 67 return regmap_write(chip->regmap, LM36274_REG_BL_EN, enable_val);68}69 70static int lm36274_parse_dt(struct lm36274 *chip,71 struct led_init_data *init_data)72{73 struct device *dev = chip->dev;74 struct fwnode_handle *child;75 int ret;76 77 /* There should only be 1 node */78 if (device_get_child_node_count(dev) != 1)79 return -EINVAL;80 81 child = device_get_next_child_node(dev, NULL);82 83 init_data->fwnode = child;84 init_data->devicename = chip->pdev->name;85 /* for backwards compatibility when `label` property is not present */86 init_data->default_label = ":";87 88 chip->num_leds = fwnode_property_count_u32(child, "led-sources");89 if (chip->num_leds <= 0) {90 ret = -ENODEV;91 goto err;92 }93 94 ret = fwnode_property_read_u32_array(child, "led-sources",95 chip->led_sources, chip->num_leds);96 if (ret) {97 dev_err(dev, "led-sources property missing\n");98 goto err;99 }100 101 return 0;102err:103 fwnode_handle_put(child);104 return ret;105}106 107static int lm36274_probe(struct platform_device *pdev)108{109 struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent);110 struct led_init_data init_data = {};111 struct lm36274 *chip;112 int ret;113 114 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);115 if (!chip)116 return -ENOMEM;117 118 chip->pdev = pdev;119 chip->dev = &pdev->dev;120 chip->regmap = lmu->regmap;121 platform_set_drvdata(pdev, chip);122 123 ret = lm36274_parse_dt(chip, &init_data);124 if (ret) {125 dev_err(chip->dev, "Failed to parse DT node\n");126 return ret;127 }128 129 ret = lm36274_init(chip);130 if (ret) {131 fwnode_handle_put(init_data.fwnode);132 dev_err(chip->dev, "Failed to init the device\n");133 return ret;134 }135 136 chip->lmu_data.regmap = chip->regmap;137 chip->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT;138 chip->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB;139 chip->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB;140 141 chip->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT;142 chip->led_dev.brightness_set_blocking = lm36274_brightness_set;143 144 ret = devm_led_classdev_register_ext(chip->dev, &chip->led_dev,145 &init_data);146 if (ret)147 dev_err(chip->dev, "Failed to register LED for node %pfw\n",148 init_data.fwnode);149 150 fwnode_handle_put(init_data.fwnode);151 152 return ret;153}154 155static const struct of_device_id of_lm36274_leds_match[] = {156 { .compatible = "ti,lm36274-backlight", },157 {},158};159MODULE_DEVICE_TABLE(of, of_lm36274_leds_match);160 161static struct platform_driver lm36274_driver = {162 .probe = lm36274_probe,163 .driver = {164 .name = "lm36274-leds",165 .of_match_table = of_lm36274_leds_match,166 },167};168module_platform_driver(lm36274_driver)169 170MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver");171MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");172MODULE_LICENSE("GPL v2");173