1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2023 Andreas Kemnade
4 *
5 * Datasheet:
6 * https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd2606mvv_1-e.pdf
7 *
8 * If LED brightness cannot be controlled independently due to shared
9 * brightness registers, max_brightness is set to 1 and only on/off
10 * is possible for the affected LED pair.
11 */
12
13 #include <linux/i2c.h>
14 #include <linux/leds.h>
15 #include <linux/module.h>
16 #include <linux/mod_devicetable.h>
17 #include <linux/property.h>
18 #include <linux/regmap.h>
19 #include <linux/slab.h>
20
21 #define BD2606_MAX_LEDS 6
22 #define BD2606_MAX_BRIGHTNESS 63
23 #define BD2606_REG_PWRCNT 3
24 #define ldev_to_led(c) container_of(c, struct bd2606mvv_led, ldev)
25
26 struct bd2606mvv_led {
27 unsigned int led_no;
28 struct led_classdev ldev;
29 struct bd2606mvv_priv *priv;
30 };
31
32 struct bd2606mvv_priv {
33 struct bd2606mvv_led leds[BD2606_MAX_LEDS];
34 struct regmap *regmap;
35 };
36
37 static int
bd2606mvv_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)38 bd2606mvv_brightness_set(struct led_classdev *led_cdev,
39 enum led_brightness brightness)
40 {
41 struct bd2606mvv_led *led = ldev_to_led(led_cdev);
42 struct bd2606mvv_priv *priv = led->priv;
43 int err;
44
45 if (brightness == 0)
46 return regmap_update_bits(priv->regmap,
47 BD2606_REG_PWRCNT,
48 1 << led->led_no,
49 0);
50
51 /* shared brightness register */
52 err = regmap_write(priv->regmap, led->led_no / 2,
53 led_cdev->max_brightness == 1 ?
54 BD2606_MAX_BRIGHTNESS : brightness);
55 if (err)
56 return err;
57
58 return regmap_update_bits(priv->regmap,
59 BD2606_REG_PWRCNT,
60 1 << led->led_no,
61 1 << led->led_no);
62 }
63
64 static const struct regmap_config bd2606mvv_regmap = {
65 .reg_bits = 8,
66 .val_bits = 8,
67 .max_register = 0x3,
68 };
69
bd2606mvv_probe(struct i2c_client * client)70 static int bd2606mvv_probe(struct i2c_client *client)
71 {
72 struct device *dev = &client->dev;
73 struct bd2606mvv_priv *priv;
74 struct fwnode_handle *led_fwnodes[BD2606_MAX_LEDS] = { 0 };
75 int active_pairs[BD2606_MAX_LEDS / 2] = { 0 };
76 int err, reg;
77 int i, j;
78
79 if (!dev_fwnode(dev))
80 return -ENODEV;
81
82 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
83 if (!priv)
84 return -ENOMEM;
85
86 priv->regmap = devm_regmap_init_i2c(client, &bd2606mvv_regmap);
87 if (IS_ERR(priv->regmap)) {
88 err = PTR_ERR(priv->regmap);
89 dev_err(dev, "Failed to allocate register map: %d\n", err);
90 return err;
91 }
92
93 i2c_set_clientdata(client, priv);
94
95 device_for_each_child_node_scoped(dev, child) {
96 struct bd2606mvv_led *led;
97
98 err = fwnode_property_read_u32(child, "reg", ®);
99 if (err)
100 return err;
101
102 if (reg < 0 || reg >= BD2606_MAX_LEDS || led_fwnodes[reg])
103 return -EINVAL;
104
105 led = &priv->leds[reg];
106 led_fwnodes[reg] = fwnode_handle_get(child);
107 active_pairs[reg / 2]++;
108 led->priv = priv;
109 led->led_no = reg;
110 led->ldev.brightness_set_blocking = bd2606mvv_brightness_set;
111 led->ldev.max_brightness = BD2606_MAX_BRIGHTNESS;
112 }
113
114 for (i = 0; i < BD2606_MAX_LEDS; i++) {
115 struct led_init_data init_data = {};
116
117 if (!led_fwnodes[i])
118 continue;
119
120 init_data.fwnode = led_fwnodes[i];
121 /* Check whether brightness can be independently adjusted. */
122 if (active_pairs[i / 2] == 2)
123 priv->leds[i].ldev.max_brightness = 1;
124
125 err = devm_led_classdev_register_ext(dev,
126 &priv->leds[i].ldev,
127 &init_data);
128 if (err < 0) {
129 for (j = i; j < BD2606_MAX_LEDS; j++)
130 fwnode_handle_put(led_fwnodes[j]);
131 return dev_err_probe(dev, err,
132 "couldn't register LED %s\n",
133 priv->leds[i].ldev.name);
134 }
135 }
136 return 0;
137 }
138
139 static const struct of_device_id __maybe_unused of_bd2606mvv_leds_match[] = {
140 { .compatible = "rohm,bd2606mvv", },
141 {},
142 };
143 MODULE_DEVICE_TABLE(of, of_bd2606mvv_leds_match);
144
145 static struct i2c_driver bd2606mvv_driver = {
146 .driver = {
147 .name = "leds-bd2606mvv",
148 .of_match_table = of_match_ptr(of_bd2606mvv_leds_match),
149 },
150 .probe = bd2606mvv_probe,
151 };
152
153 module_i2c_driver(bd2606mvv_driver);
154
155 MODULE_AUTHOR("Andreas Kemnade <andreas@kemnade.info>");
156 MODULE_DESCRIPTION("BD2606 LED driver");
157 MODULE_LICENSE("GPL");
158