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
 41struct pca995x_chipdef {
 42	unsigned int num_leds;
 43	u8 pwm_base;
 44	u8 irefall;
 45};
 46
 47static const struct pca995x_chipdef pca9952_chipdef = {
 48	.num_leds	= 16,
 49	.pwm_base	= 0x0a,
 50	.irefall	= 0x43,
 51};
 52
 53static const struct pca995x_chipdef pca9955b_chipdef = {
 54	.num_leds	= 16,
 55	.pwm_base	= 0x08,
 56	.irefall	= 0x45,
 57};
 58
 59static const struct pca995x_chipdef pca9956b_chipdef = {
 60	.num_leds	= 24,
 61	.pwm_base	= 0x0a,
 62	.irefall	= 0x40,
 63};
 64
 65struct pca995x_led {
 66	unsigned int led_no;
 67	struct led_classdev ldev;
 68	struct pca995x_chip *chip;
 69};
 70
 71struct pca995x_chip {
 72	struct regmap *regmap;
 73	struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
 74	const struct pca995x_chipdef *chipdef;
 75};
 76
 77static 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
114static const struct regmap_config pca995x_regmap = {
115	.reg_bits = 8,
116	.val_bits = 8,
117	.max_register = 0x49,
118};
119
120static 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
190static 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};
196MODULE_DEVICE_TABLE(i2c, pca995x_id);
197
198static 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};
204MODULE_DEVICE_TABLE(of, pca995x_of_match);
205
206static 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};
214module_i2c_driver(pca995x_driver);
215
216MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
217MODULE_DESCRIPTION("PCA995x LED driver");
218MODULE_LICENSE("GPL");