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(map: 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 *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: dev->parent, NULL);
55 if (!regmap)
56 return -ENODEV;
57
58 struct fwnode_handle *led_node __free(fwnode_handle) =
59 device_get_named_child_node(dev: dev->parent, childname: "leds");
60 if (!led_node)
61 return -ENODEV;
62
63 fwnode_for_each_available_child_node(led_node, child) {
64 u32 reg;
65
66 if (fwnode_property_read_u32(fwnode: child, propname: "reg", val: &reg))
67 continue;
68
69 if (reg >= MAX5970_NUM_LEDS) {
70 dev_err_probe(dev, err: -EINVAL, fmt: "invalid LED (%u >= %d)\n", reg, MAX5970_NUM_LEDS);
71 continue;
72 }
73
74 ddata = devm_kzalloc(dev, size: sizeof(*ddata), GFP_KERNEL);
75 if (!ddata) {
76 fwnode_handle_put(fwnode: child);
77 return -ENOMEM;
78 }
79
80 ddata->index = reg;
81 ddata->regmap = regmap;
82 ddata->dev = dev;
83
84 if (fwnode_property_read_string(fwnode: child, propname: "label", val: &ddata->cdev.name))
85 ddata->cdev.name = fwnode_get_name(fwnode: child);
86
87 ddata->cdev.max_brightness = 1;
88 ddata->cdev.brightness_set_blocking = max5970_led_set_brightness;
89 ddata->cdev.default_trigger = "none";
90
91 ret = devm_led_classdev_register(parent: dev, led_cdev: &ddata->cdev);
92 if (ret < 0) {
93 fwnode_handle_put(fwnode: child);
94 return dev_err_probe(dev, err: ret, fmt: "Failed to initialize LED %u\n", reg);
95 }
96 }
97
98 return ret;
99}
100
101static struct platform_driver max5970_led_driver = {
102 .driver = {
103 .name = "max5970-led",
104 },
105 .probe = max5970_led_probe,
106};
107module_platform_driver(max5970_led_driver);
108
109MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
110MODULE_AUTHOR("Naresh Solanki <Naresh.Solanki@9elements.com>");
111MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
112MODULE_LICENSE("GPL");
113

source code of linux/drivers/leds/leds-max5970.c