1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Device driver for leds in MAX5970 and MAX5978 IC
  4 *
  5 * Copyright (c) 2022 9elements GmbH
  6 *
  7 * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
  8 */
  9
 10#include <linux/bits.h>
 11#include <linux/container_of.h>
 12#include <linux/device.h>
 13#include <linux/leds.h>
 14#include <linux/mfd/max5970.h>
 15#include <linux/mod_devicetable.h>
 16#include <linux/module.h>
 17#include <linux/platform_device.h>
 18#include <linux/property.h>
 19#include <linux/regmap.h>
 20
 21#define ldev_to_maxled(c)       container_of(c, struct max5970_led, cdev)
 22
 23struct max5970_led {
 24	struct device *dev;
 25	struct regmap *regmap;
 26	struct led_classdev cdev;
 27	unsigned int index;
 28};
 29
 30static int max5970_led_set_brightness(struct led_classdev *cdev,
 31				      enum led_brightness brightness)
 32{
 33	struct max5970_led *ddata = ldev_to_maxled(cdev);
 34	int ret, val;
 35
 36	/* Set/clear corresponding bit for given led index */
 37	val = !brightness ? BIT(ddata->index) : 0;
 38
 39	ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
 40	if (ret < 0)
 41		dev_err(cdev->dev, "failed to set brightness %d", ret);
 42
 43	return ret;
 44}
 45
 46static int max5970_led_probe(struct platform_device *pdev)
 47{
 48	struct fwnode_handle *led_node, *child;
 49	struct device *dev = &pdev->dev;
 50	struct regmap *regmap;
 51	struct max5970_led *ddata;
 52	int ret = -ENODEV;
 53
 54	regmap = dev_get_regmap(dev->parent, NULL);
 55	if (!regmap)
 56		return -ENODEV;
 57
 58	led_node = device_get_named_child_node(dev->parent, "leds");
 59	if (!led_node)
 60		return -ENODEV;
 61
 62	fwnode_for_each_available_child_node(led_node, child) {
 63		u32 reg;
 64
 65		if (fwnode_property_read_u32(child, "reg", &reg))
 66			continue;
 67
 68		if (reg >= MAX5970_NUM_LEDS) {
 69			dev_err_probe(dev, -EINVAL, "invalid LED (%u >= %d)\n", reg, MAX5970_NUM_LEDS);
 70			continue;
 71		}
 72
 73		ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 74		if (!ddata) {
 75			fwnode_handle_put(child);
 76			return -ENOMEM;
 77		}
 78
 79		ddata->index = reg;
 80		ddata->regmap = regmap;
 81		ddata->dev = dev;
 82
 83		if (fwnode_property_read_string(child, "label", &ddata->cdev.name))
 84			ddata->cdev.name = fwnode_get_name(child);
 85
 86		ddata->cdev.max_brightness = 1;
 87		ddata->cdev.brightness_set_blocking = max5970_led_set_brightness;
 88		ddata->cdev.default_trigger = "none";
 89
 90		ret = devm_led_classdev_register(dev, &ddata->cdev);
 91		if (ret < 0) {
 92			fwnode_handle_put(child);
 93			return dev_err_probe(dev, ret, "Failed to initialize LED %u\n", reg);
 94		}
 95	}
 96
 97	return ret;
 98}
 99
100static struct platform_driver max5970_led_driver = {
101	.driver = {
102		.name = "max5970-led",
103	},
104	.probe = max5970_led_probe,
105};
106module_platform_driver(max5970_led_driver);
107
108MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
109MODULE_AUTHOR("Naresh Solanki <Naresh.Solanki@9elements.com>");
110MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
111MODULE_LICENSE("GPL");