1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED driver for PCA995x I2C LED drivers
4 *
5 * Copyright 2011 bct electronic GmbH
6 * Copyright 2013 Qtechnology/AS
7 * Copyright 2022 NXP
8 * Copyright 2023 Marek Vasut
9 */
10
11#include <linux/i2c.h>
12#include <linux/leds.h>
13#include <linux/module.h>
14#include <linux/mod_devicetable.h>
15#include <linux/property.h>
16#include <linux/regmap.h>
17
18/* Register definition */
19#define PCA995X_MODE1 0x00
20#define PCA995X_MODE2 0x01
21#define PCA995X_LEDOUT0 0x02
22#define PCA9955B_PWM0 0x08
23#define PCA9952_PWM0 0x0A
24#define PCA9952_IREFALL 0x43
25#define PCA9955B_IREFALL 0x45
26
27/* Auto-increment disabled. Normal mode */
28#define PCA995X_MODE1_CFG 0x00
29
30/* LED select registers determine the source that drives LED outputs */
31#define PCA995X_LED_OFF 0x0
32#define PCA995X_LED_ON 0x1
33#define PCA995X_LED_PWM_MODE 0x2
34#define PCA995X_LDRX_MASK 0x3
35#define PCA995X_LDRX_BITS 2
36
37#define PCA995X_MAX_OUTPUTS 16
38#define PCA995X_OUTPUTS_PER_REG 4
39
40#define PCA995X_IREFALL_FULL_CFG 0xFF
41#define PCA995X_IREFALL_HALF_CFG (PCA995X_IREFALL_FULL_CFG / 2)
42
43#define PCA995X_TYPE_NON_B 0
44#define PCA995X_TYPE_B 1
45
46#define ldev_to_led(c) container_of(c, struct pca995x_led, ldev)
47
48struct pca995x_led {
49 unsigned int led_no;
50 struct led_classdev ldev;
51 struct pca995x_chip *chip;
52};
53
54struct pca995x_chip {
55 struct regmap *regmap;
56 struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
57 int btype;
58};
59
60static int pca995x_brightness_set(struct led_classdev *led_cdev,
61 enum led_brightness brightness)
62{
63 struct pca995x_led *led = ldev_to_led(led_cdev);
64 struct pca995x_chip *chip = led->chip;
65 u8 ledout_addr, pwmout_addr;
66 int shift, ret;
67
68 pwmout_addr = (chip->btype ? PCA9955B_PWM0 : PCA9952_PWM0) + led->led_no;
69 ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
70 shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
71
72 switch (brightness) {
73 case LED_FULL:
74 return regmap_update_bits(map: chip->regmap, reg: ledout_addr,
75 PCA995X_LDRX_MASK << shift,
76 PCA995X_LED_ON << shift);
77 case LED_OFF:
78 return regmap_update_bits(map: chip->regmap, reg: ledout_addr,
79 PCA995X_LDRX_MASK << shift, val: 0);
80 default:
81 /* Adjust brightness as per user input by changing individual PWM */
82 ret = regmap_write(map: chip->regmap, reg: pwmout_addr, val: brightness);
83 if (ret)
84 return ret;
85
86 /*
87 * Change LDRx configuration to individual brightness via PWM.
88 * LED will stop blinking if it's doing so.
89 */
90 return regmap_update_bits(map: chip->regmap, reg: ledout_addr,
91 PCA995X_LDRX_MASK << shift,
92 PCA995X_LED_PWM_MODE << shift);
93 }
94}
95
96static const struct regmap_config pca995x_regmap = {
97 .reg_bits = 8,
98 .val_bits = 8,
99 .max_register = 0x49,
100};
101
102static int pca995x_probe(struct i2c_client *client)
103{
104 struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
105 struct fwnode_handle *np, *child;
106 struct device *dev = &client->dev;
107 struct pca995x_chip *chip;
108 struct pca995x_led *led;
109 int i, btype, reg, ret;
110
111 btype = (unsigned long)device_get_match_data(dev: &client->dev);
112
113 np = dev_fwnode(dev);
114 if (!np)
115 return -ENODEV;
116
117 chip = devm_kzalloc(dev, size: sizeof(*chip), GFP_KERNEL);
118 if (!chip)
119 return -ENOMEM;
120
121 chip->btype = btype;
122 chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
123 if (IS_ERR(ptr: chip->regmap))
124 return PTR_ERR(ptr: chip->regmap);
125
126 i2c_set_clientdata(client, data: chip);
127
128 fwnode_for_each_available_child_node(np, child) {
129 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &reg);
130 if (ret) {
131 fwnode_handle_put(fwnode: child);
132 return ret;
133 }
134
135 if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg]) {
136 fwnode_handle_put(fwnode: child);
137 return -EINVAL;
138 }
139
140 led = &chip->leds[reg];
141 led_fwnodes[reg] = child;
142 led->chip = chip;
143 led->led_no = reg;
144 led->ldev.brightness_set_blocking = pca995x_brightness_set;
145 led->ldev.max_brightness = 255;
146 }
147
148 for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
149 struct led_init_data init_data = {};
150
151 if (!led_fwnodes[i])
152 continue;
153
154 init_data.fwnode = led_fwnodes[i];
155
156 ret = devm_led_classdev_register_ext(parent: dev,
157 led_cdev: &chip->leds[i].ldev,
158 init_data: &init_data);
159 if (ret < 0) {
160 fwnode_handle_put(fwnode: child);
161 return dev_err_probe(dev, err: ret,
162 fmt: "Could not register LED %s\n",
163 chip->leds[i].ldev.name);
164 }
165 }
166
167 /* Disable LED all-call address and set normal mode */
168 ret = regmap_write(map: chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
169 if (ret)
170 return ret;
171
172 /* IREF Output current value for all LEDn outputs */
173 return regmap_write(map: chip->regmap,
174 reg: btype ? PCA9955B_IREFALL : PCA9952_IREFALL,
175 PCA995X_IREFALL_HALF_CFG);
176}
177
178static const struct i2c_device_id pca995x_id[] = {
179 { "pca9952", .driver_data = (kernel_ulong_t)PCA995X_TYPE_NON_B },
180 { "pca9955b", .driver_data = (kernel_ulong_t)PCA995X_TYPE_B },
181 {}
182};
183MODULE_DEVICE_TABLE(i2c, pca995x_id);
184
185static const struct of_device_id pca995x_of_match[] = {
186 { .compatible = "nxp,pca9952", .data = (void *)PCA995X_TYPE_NON_B },
187 { .compatible = "nxp,pca9955b", .data = (void *)PCA995X_TYPE_B },
188 {},
189};
190MODULE_DEVICE_TABLE(of, pca995x_of_match);
191
192static struct i2c_driver pca995x_driver = {
193 .driver = {
194 .name = "leds-pca995x",
195 .of_match_table = pca995x_of_match,
196 },
197 .probe = pca995x_probe,
198 .id_table = pca995x_id,
199};
200module_i2c_driver(pca995x_driver);
201
202MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
203MODULE_DESCRIPTION("PCA995x LED driver");
204MODULE_LICENSE("GPL");
205

source code of linux/drivers/leds/leds-pca995x.c