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