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
23 struct max5970_led {
24 struct device *dev;
25 struct regmap *regmap;
26 struct led_classdev cdev;
27 unsigned int index;
28 };
29
max5970_led_set_brightness(struct led_classdev * cdev,enum led_brightness brightness)30 static 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
max5970_led_probe(struct platform_device * pdev)46 static 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", ®))
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
100 static struct platform_driver max5970_led_driver = {
101 .driver = {
102 .name = "max5970-led",
103 },
104 .probe = max5970_led_probe,
105 };
106 module_platform_driver(max5970_led_driver);
107
108 MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
109 MODULE_AUTHOR("Naresh Solanki <Naresh.Solanki@9elements.com>");
110 MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
111 MODULE_LICENSE("GPL");
112