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
23 /* Auto-increment disabled. Normal mode */
24 #define PCA995X_MODE1_CFG 0x00
25
26 /* LED select registers determine the source that drives LED outputs */
27 #define PCA995X_LED_OFF 0x0
28 #define PCA995X_LED_ON 0x1
29 #define PCA995X_LED_PWM_MODE 0x2
30 #define PCA995X_LDRX_MASK 0x3
31 #define PCA995X_LDRX_BITS 2
32
33 #define PCA995X_MAX_OUTPUTS 24
34 #define PCA995X_OUTPUTS_PER_REG 4
35
36 #define PCA995X_IREFALL_FULL_CFG 0xFF
37 #define PCA995X_IREFALL_HALF_CFG (PCA995X_IREFALL_FULL_CFG / 2)
38
39 #define ldev_to_led(c) container_of(c, struct pca995x_led, ldev)
40
41 struct pca995x_chipdef {
42 unsigned int num_leds;
43 u8 pwm_base;
44 u8 irefall;
45 };
46
47 static const struct pca995x_chipdef pca9952_chipdef = {
48 .num_leds = 16,
49 .pwm_base = 0x0a,
50 .irefall = 0x43,
51 };
52
53 static const struct pca995x_chipdef pca9955b_chipdef = {
54 .num_leds = 16,
55 .pwm_base = 0x08,
56 .irefall = 0x45,
57 };
58
59 static const struct pca995x_chipdef pca9956b_chipdef = {
60 .num_leds = 24,
61 .pwm_base = 0x0a,
62 .irefall = 0x40,
63 };
64
65 struct pca995x_led {
66 unsigned int led_no;
67 struct led_classdev ldev;
68 struct pca995x_chip *chip;
69 };
70
71 struct pca995x_chip {
72 struct regmap *regmap;
73 struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
74 const struct pca995x_chipdef *chipdef;
75 };
76
pca995x_brightness_set(struct led_classdev * led_cdev,enum led_brightness brightness)77 static int pca995x_brightness_set(struct led_classdev *led_cdev,
78 enum led_brightness brightness)
79 {
80 struct pca995x_led *led = ldev_to_led(led_cdev);
81 struct pca995x_chip *chip = led->chip;
82 const struct pca995x_chipdef *chipdef = chip->chipdef;
83 u8 ledout_addr, pwmout_addr;
84 int shift, ret;
85
86 pwmout_addr = chipdef->pwm_base + led->led_no;
87 ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
88 shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
89
90 switch (brightness) {
91 case LED_FULL:
92 return regmap_update_bits(chip->regmap, ledout_addr,
93 PCA995X_LDRX_MASK << shift,
94 PCA995X_LED_ON << shift);
95 case LED_OFF:
96 return regmap_update_bits(chip->regmap, ledout_addr,
97 PCA995X_LDRX_MASK << shift, 0);
98 default:
99 /* Adjust brightness as per user input by changing individual PWM */
100 ret = regmap_write(chip->regmap, pwmout_addr, brightness);
101 if (ret)
102 return ret;
103
104 /*
105 * Change LDRx configuration to individual brightness via PWM.
106 * LED will stop blinking if it's doing so.
107 */
108 return regmap_update_bits(chip->regmap, ledout_addr,
109 PCA995X_LDRX_MASK << shift,
110 PCA995X_LED_PWM_MODE << shift);
111 }
112 }
113
114 static const struct regmap_config pca995x_regmap = {
115 .reg_bits = 8,
116 .val_bits = 8,
117 .max_register = 0x49,
118 };
119
pca995x_probe(struct i2c_client * client)120 static int pca995x_probe(struct i2c_client *client)
121 {
122 struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
123 struct device *dev = &client->dev;
124 const struct pca995x_chipdef *chipdef;
125 struct pca995x_chip *chip;
126 struct pca995x_led *led;
127 int i, j, reg, ret;
128
129 chipdef = device_get_match_data(&client->dev);
130
131 if (!dev_fwnode(dev))
132 return -ENODEV;
133
134 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
135 if (!chip)
136 return -ENOMEM;
137
138 chip->chipdef = chipdef;
139 chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
140 if (IS_ERR(chip->regmap))
141 return PTR_ERR(chip->regmap);
142
143 i2c_set_clientdata(client, chip);
144
145 device_for_each_child_node_scoped(dev, child) {
146 ret = fwnode_property_read_u32(child, "reg", ®);
147 if (ret)
148 return ret;
149
150 if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg])
151 return -EINVAL;
152
153 led = &chip->leds[reg];
154 led_fwnodes[reg] = fwnode_handle_get(child);
155 led->chip = chip;
156 led->led_no = reg;
157 led->ldev.brightness_set_blocking = pca995x_brightness_set;
158 led->ldev.max_brightness = 255;
159 }
160
161 for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
162 struct led_init_data init_data = {};
163
164 if (!led_fwnodes[i])
165 continue;
166
167 init_data.fwnode = led_fwnodes[i];
168
169 ret = devm_led_classdev_register_ext(dev,
170 &chip->leds[i].ldev,
171 &init_data);
172 if (ret < 0) {
173 for (j = i; j < PCA995X_MAX_OUTPUTS; j++)
174 fwnode_handle_put(led_fwnodes[j]);
175 return dev_err_probe(dev, ret,
176 "Could not register LED %s\n",
177 chip->leds[i].ldev.name);
178 }
179 }
180
181 /* Disable LED all-call address and set normal mode */
182 ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
183 if (ret)
184 return ret;
185
186 /* IREF Output current value for all LEDn outputs */
187 return regmap_write(chip->regmap, chipdef->irefall, PCA995X_IREFALL_HALF_CFG);
188 }
189
190 static const struct i2c_device_id pca995x_id[] = {
191 { "pca9952", .driver_data = (kernel_ulong_t)&pca9952_chipdef },
192 { "pca9955b", .driver_data = (kernel_ulong_t)&pca9955b_chipdef },
193 { "pca9956b", .driver_data = (kernel_ulong_t)&pca9956b_chipdef },
194 {}
195 };
196 MODULE_DEVICE_TABLE(i2c, pca995x_id);
197
198 static const struct of_device_id pca995x_of_match[] = {
199 { .compatible = "nxp,pca9952", .data = &pca9952_chipdef },
200 { .compatible = "nxp,pca9955b", . data = &pca9955b_chipdef },
201 { .compatible = "nxp,pca9956b", .data = &pca9956b_chipdef },
202 {},
203 };
204 MODULE_DEVICE_TABLE(of, pca995x_of_match);
205
206 static struct i2c_driver pca995x_driver = {
207 .driver = {
208 .name = "leds-pca995x",
209 .of_match_table = pca995x_of_match,
210 },
211 .probe = pca995x_probe,
212 .id_table = pca995x_id,
213 };
214 module_i2c_driver(pca995x_driver);
215
216 MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
217 MODULE_DESCRIPTION("PCA995x LED driver");
218 MODULE_LICENSE("GPL");
219