xref: /openbmc/linux/drivers/leds/leds-pca995x.c (revision 34d6f206a88c2651d216bd3487ac956a40b2ba8e)
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", &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