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/property.h>
15 #include <linux/regmap.h>
16
17 /* Register definition */
18 #define PCA995X_MODE1 0x00
19 #define PCA995X_MODE2 0x01
20 #define PCA995X_LEDOUT0 0x02
21
22 /* Auto-increment disabled. Normal mode */
23 #define PCA995X_MODE1_CFG 0x00
24
25 /* LED select registers determine the source that drives LED outputs */
26 #define PCA995X_LED_OFF 0x0
27 #define PCA995X_LED_ON 0x1
28 #define PCA995X_LED_PWM_MODE 0x2
29 #define PCA995X_LDRX_MASK 0x3
30 #define PCA995X_LDRX_BITS 2
31
32 #define PCA995X_MAX_OUTPUTS 24
33 #define PCA995X_OUTPUTS_PER_REG 4
34
35 #define PCA995X_IREFALL_FULL_CFG 0xFF
36 #define PCA995X_IREFALL_HALF_CFG (PCA995X_IREFALL_FULL_CFG / 2)
37
38 #define ldev_to_led(c) container_of(c, struct pca995x_led, ldev)
39
40 struct pca995x_chipdef {
41 unsigned int num_leds;
42 u8 pwm_base;
43 u8 irefall;
44 };
45
46 static const struct pca995x_chipdef pca9952_chipdef = {
47 .num_leds = 16,
48 .pwm_base = 0x0a,
49 .irefall = 0x43,
50 };
51
52 static const struct pca995x_chipdef pca9955b_chipdef = {
53 .num_leds = 16,
54 .pwm_base = 0x08,
55 .irefall = 0x45,
56 };
57
58 static const struct pca995x_chipdef pca9956b_chipdef = {
59 .num_leds = 24,
60 .pwm_base = 0x0a,
61 .irefall = 0x40,
62 };
63
64 struct pca995x_led {
65 unsigned int led_no;
66 struct led_classdev ldev;
67 struct pca995x_chip *chip;
68 };
69
70 struct pca995x_chip {
71 struct regmap *regmap;
72 struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
73 const struct pca995x_chipdef *chipdef;
74 };
75
pca995x_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)76 static int pca995x_brightness_set(struct led_classdev *led_cdev,
77 enum led_brightness brightness)
78 {
79 struct pca995x_led *led = ldev_to_led(led_cdev);
80 struct pca995x_chip *chip = led->chip;
81 const struct pca995x_chipdef *chipdef = chip->chipdef;
82 u8 ledout_addr, pwmout_addr;
83 int shift, ret;
84
85 pwmout_addr = chipdef->pwm_base + led->led_no;
86 ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
87 shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
88
89 switch (brightness) {
90 case LED_FULL:
91 return regmap_update_bits(chip->regmap, ledout_addr,
92 PCA995X_LDRX_MASK << shift,
93 PCA995X_LED_ON << shift);
94 case LED_OFF:
95 return regmap_update_bits(chip->regmap, ledout_addr,
96 PCA995X_LDRX_MASK << shift, 0);
97 default:
98 /* Adjust brightness as per user input by changing individual PWM */
99 ret = regmap_write(chip->regmap, pwmout_addr, brightness);
100 if (ret)
101 return ret;
102
103 /*
104 * Change LDRx configuration to individual brightness via PWM.
105 * LED will stop blinking if it's doing so.
106 */
107 return regmap_update_bits(chip->regmap, ledout_addr,
108 PCA995X_LDRX_MASK << shift,
109 PCA995X_LED_PWM_MODE << shift);
110 }
111 }
112
113 static const struct regmap_config pca995x_regmap = {
114 .reg_bits = 8,
115 .val_bits = 8,
116 .max_register = 0x49,
117 };
118
pca995x_probe(struct i2c_client * client)119 static int pca995x_probe(struct i2c_client *client)
120 {
121 struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
122 struct device *dev = &client->dev;
123 const struct pca995x_chipdef *chipdef;
124 struct pca995x_chip *chip;
125 struct pca995x_led *led;
126 int i, j, reg, ret;
127
128 chipdef = device_get_match_data(&client->dev);
129
130 if (!dev_fwnode(dev))
131 return -ENODEV;
132
133 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
134 if (!chip)
135 return -ENOMEM;
136
137 chip->chipdef = chipdef;
138 chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
139 if (IS_ERR(chip->regmap))
140 return PTR_ERR(chip->regmap);
141
142 i2c_set_clientdata(client, chip);
143
144 device_for_each_child_node_scoped(dev, child) {
145 ret = fwnode_property_read_u32(child, "reg", ®);
146 if (ret)
147 return ret;
148
149 if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg])
150 return -EINVAL;
151
152 led = &chip->leds[reg];
153 led_fwnodes[reg] = fwnode_handle_get(child);
154 led->chip = chip;
155 led->led_no = reg;
156 led->ldev.brightness_set_blocking = pca995x_brightness_set;
157 led->ldev.max_brightness = 255;
158 }
159
160 for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
161 struct led_init_data init_data = {};
162
163 if (!led_fwnodes[i])
164 continue;
165
166 init_data.fwnode = led_fwnodes[i];
167
168 ret = devm_led_classdev_register_ext(dev,
169 &chip->leds[i].ldev,
170 &init_data);
171 if (ret < 0) {
172 for (j = i; j < PCA995X_MAX_OUTPUTS; j++)
173 fwnode_handle_put(led_fwnodes[j]);
174 return dev_err_probe(dev, ret,
175 "Could not register LED %s\n",
176 chip->leds[i].ldev.name);
177 }
178 }
179
180 /* Disable LED all-call address and set normal mode */
181 ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
182 if (ret)
183 return ret;
184
185 /* IREF Output current value for all LEDn outputs */
186 return regmap_write(chip->regmap, chipdef->irefall, PCA995X_IREFALL_HALF_CFG);
187 }
188
189 static const struct i2c_device_id pca995x_id[] = {
190 { .name = "pca9952", .driver_data = (kernel_ulong_t)&pca9952_chipdef },
191 { .name = "pca9955b", .driver_data = (kernel_ulong_t)&pca9955b_chipdef },
192 { .name = "pca9956b", .driver_data = (kernel_ulong_t)&pca9956b_chipdef },
193 { }
194 };
195 MODULE_DEVICE_TABLE(i2c, pca995x_id);
196
197 static const struct of_device_id pca995x_of_match[] = {
198 { .compatible = "nxp,pca9952", .data = &pca9952_chipdef },
199 { .compatible = "nxp,pca9955b", .data = &pca9955b_chipdef },
200 { .compatible = "nxp,pca9956b", .data = &pca9956b_chipdef },
201 {},
202 };
203 MODULE_DEVICE_TABLE(of, pca995x_of_match);
204
205 static struct i2c_driver pca995x_driver = {
206 .driver = {
207 .name = "leds-pca995x",
208 .of_match_table = pca995x_of_match,
209 },
210 .probe = pca995x_probe,
211 .id_table = pca995x_id,
212 };
213 module_i2c_driver(pca995x_driver);
214
215 MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
216 MODULE_DESCRIPTION("PCA995x LED driver");
217 MODULE_LICENSE("GPL");
218