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");
112