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(chip->regmap, ledout_addr,
 75					  PCA995X_LDRX_MASK << shift,
 76					  PCA995X_LED_ON << shift);
 77	case LED_OFF:
 78		return regmap_update_bits(chip->regmap, ledout_addr,
 79					  PCA995X_LDRX_MASK << shift, 0);
 80	default:
 81		/* Adjust brightness as per user input by changing individual PWM */
 82		ret = regmap_write(chip->regmap, pwmout_addr, 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(chip->regmap, 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(&client->dev);
112
113	np = dev_fwnode(dev);
114	if (!np)
115		return -ENODEV;
116
117	chip = devm_kzalloc(dev, 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(chip->regmap))
124		return PTR_ERR(chip->regmap);
125
126	i2c_set_clientdata(client, chip);
127
128	fwnode_for_each_available_child_node(np, child) {
129		ret = fwnode_property_read_u32(child, "reg", &reg);
130		if (ret) {
131			fwnode_handle_put(child);
132			return ret;
133		}
134
135		if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg]) {
136			fwnode_handle_put(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(dev,
157						     &chip->leds[i].ldev,
158						     &init_data);
159		if (ret < 0) {
160			fwnode_handle_put(child);
161			return dev_err_probe(dev, ret,
162					     "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(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(chip->regmap,
174			    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");