[mirror_ubuntu-jammy-kernel.git] / drivers / leds / leds-is31fl319x.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2015-16 Golden Delicious Computers
 *
 * Author: Nikolaus Schaller <hns@goldelico.com>
 *
 * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
 * effect LEDs.
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>

/* register numbers */
#define IS31FL319X_SHUTDOWN		0x00
#define IS31FL319X_CTRL1		0x01
#define IS31FL319X_CTRL2		0x02
#define IS31FL319X_CONFIG1		0x03
#define IS31FL319X_CONFIG2		0x04
#define IS31FL319X_RAMP_MODE		0x05
#define IS31FL319X_BREATH_MASK		0x06
#define IS31FL319X_PWM(channel)		(0x07 + channel)
#define IS31FL319X_DATA_UPDATE		0x10
#define IS31FL319X_T0(channel)		(0x11 + channel)
#define IS31FL319X_T123_1		0x1a
#define IS31FL319X_T123_2		0x1b
#define IS31FL319X_T123_3		0x1c
#define IS31FL319X_T4(channel)		(0x1d + channel)
#define IS31FL319X_TIME_UPDATE		0x26
#define IS31FL319X_RESET		0xff

#define IS31FL319X_REG_CNT		(IS31FL319X_RESET + 1)

#define IS31FL319X_MAX_LEDS		9

/* CS (Current Setting) in CONFIG2 register */
#define IS31FL319X_CONFIG2_CS_SHIFT	4
#define IS31FL319X_CONFIG2_CS_MASK	0x7
#define IS31FL319X_CONFIG2_CS_STEP_REF	12

#define IS31FL319X_CURRENT_MIN		((u32)5000)
#define IS31FL319X_CURRENT_MAX		((u32)40000)
#define IS31FL319X_CURRENT_STEP		((u32)5000)
#define IS31FL319X_CURRENT_DEFAULT	((u32)20000)

/* Audio gain in CONFIG2 register */
#define IS31FL319X_AUDIO_GAIN_DB_MAX	((u32)21)
#define IS31FL319X_AUDIO_GAIN_DB_STEP	((u32)3)

/*
 * regmap is used as a cache of chip's register space,
 * to avoid reading back brightness values from chip,
 * which is known to hang.
 */
struct is31fl319x_chip {
	const struct is31fl319x_chipdef *cdef;
	struct i2c_client               *client;
	struct gpio_desc		*shutdown_gpio;
	struct regmap                   *regmap;
	struct mutex                    lock;
	u32                             audio_gain_db;

	struct is31fl319x_led {
		struct is31fl319x_chip  *chip;
		struct led_classdev     cdev;
		u32                     max_microamp;
		bool                    configured;
	} leds[IS31FL319X_MAX_LEDS];
};

struct is31fl319x_chipdef {
	int num_leds;
};

static const struct is31fl319x_chipdef is31fl3190_cdef = {
	.num_leds = 1,
};

static const struct is31fl319x_chipdef is31fl3193_cdef = {
	.num_leds = 3,
};

static const struct is31fl319x_chipdef is31fl3196_cdef = {
	.num_leds = 6,
};

static const struct is31fl319x_chipdef is31fl3199_cdef = {
	.num_leds = 9,
};

static const struct of_device_id of_is31fl319x_match[] = {
	{ .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
	{ .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
	{ .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
	{ .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
	{ .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
	{ .compatible = "si-en,sn3199",    .data = &is31fl3199_cdef, },
	{ }
};
MODULE_DEVICE_TABLE(of, of_is31fl319x_match);

static int is31fl319x_brightness_set(struct led_classdev *cdev,
				     enum led_brightness brightness)
{
	struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
						  cdev);
	struct is31fl319x_chip *is31 = led->chip;
	int chan = led - is31->leds;
	int ret;
	int i;
	u8 ctrl1 = 0, ctrl2 = 0;

	dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);

	mutex_lock(&is31->lock);

	/* update PWM register */
	ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
	if (ret < 0)
		goto out;

	/* read current brightness of all PWM channels */
	for (i = 0; i < is31->cdef->num_leds; i++) {
		unsigned int pwm_value;
		bool on;

		/*
		 * since neither cdev nor the chip can provide
		 * the current setting, we read from the regmap cache
		 */

		ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
		dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
			__func__, i, ret, pwm_value);
		on = ret >= 0 && pwm_value > LED_OFF;

		if (i < 3)
			ctrl1 |= on << i;       /* 0..2 => bit 0..2 */
		else if (i < 6)
			ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */
		else
			ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */
	}

	if (ctrl1 > 0 || ctrl2 > 0) {
		dev_dbg(&is31->client->dev, "power up %02x %02x\n",
			ctrl1, ctrl2);
		regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
		regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
		/* update PWMs */
		regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
		/* enable chip from shut down */
		ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
	} else {
		dev_dbg(&is31->client->dev, "power down\n");
		/* shut down (no need to clear CTRL1/2) */
		ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
	}

out:
	mutex_unlock(&is31->lock);

	return ret;
}

static int is31fl319x_parse_child_dt(const struct device *dev,
				     const struct device_node *child,
				     struct is31fl319x_led *led)
{
	struct led_classdev *cdev = &led->cdev;
	int ret;

	if (of_property_read_string(child, "label", &cdev->name))
		cdev->name = child->name;

	ret = of_property_read_string(child, "linux,default-trigger",
				      &cdev->default_trigger);
	if (ret < 0 && ret != -EINVAL) /* is optional */
		return ret;

	led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
	ret = of_property_read_u32(child, "led-max-microamp",
				   &led->max_microamp);
	if (!ret) {
		if (led->max_microamp < IS31FL319X_CURRENT_MIN)
			return -EINVAL;	/* not supported */
		led->max_microamp = min(led->max_microamp,
					  IS31FL319X_CURRENT_MAX);
	}

	return 0;
}

static int is31fl319x_parse_dt(struct device *dev,
			       struct is31fl319x_chip *is31)
{
	struct device_node *np = dev->of_node, *child;
	const struct of_device_id *of_dev_id;
	int count;
	int ret;

	if (!np)
		return -ENODEV;

	is31->shutdown_gpio = devm_gpiod_get_optional(dev,
						"shutdown",
						GPIOD_OUT_HIGH);
	if (IS_ERR(is31->shutdown_gpio)) {
		ret = PTR_ERR(is31->shutdown_gpio);
		dev_err(dev, "Failed to get shutdown gpio: %d\n", ret);
		return ret;
	}

	of_dev_id = of_match_device(of_is31fl319x_match, dev);
	if (!of_dev_id) {
		dev_err(dev, "Failed to match device with supported chips\n");
		return -EINVAL;
	}

	is31->cdef = of_dev_id->data;

	count = of_get_child_count(np);

	dev_dbg(dev, "probe %s with %d leds defined in DT\n",
		of_dev_id->compatible, count);

	if (!count || count > is31->cdef->num_leds) {
		dev_err(dev, "Number of leds defined must be between 1 and %u\n",
			is31->cdef->num_leds);
		return -ENODEV;
	}

	for_each_child_of_node(np, child) {
		struct is31fl319x_led *led;
		u32 reg;

		ret = of_property_read_u32(child, "reg", &reg);
		if (ret) {
			dev_err(dev, "Failed to read led 'reg' property\n");
			goto put_child_node;
		}

		if (reg < 1 || reg > is31->cdef->num_leds) {
			dev_err(dev, "invalid led reg %u\n", reg);
			ret = -EINVAL;
			goto put_child_node;
		}

		led = &is31->leds[reg - 1];

		if (led->configured) {
			dev_err(dev, "led %u is already configured\n", reg);
			ret = -EINVAL;
			goto put_child_node;
		}

		ret = is31fl319x_parse_child_dt(dev, child, led);
		if (ret) {
			dev_err(dev, "led %u DT parsing failed\n", reg);
			goto put_child_node;
		}

		led->configured = true;
	}

	is31->audio_gain_db = 0;
	ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
	if (!ret)
		is31->audio_gain_db = min(is31->audio_gain_db,
					  IS31FL319X_AUDIO_GAIN_DB_MAX);

	return 0;

put_child_node:
	of_node_put(child);
	return ret;
}

static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
{ /* we have no readable registers */
	return false;
}

static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
{ /* volatile registers are not cached */
	switch (reg) {
	case IS31FL319X_DATA_UPDATE:
	case IS31FL319X_TIME_UPDATE:
	case IS31FL319X_RESET:
		return true; /* always write-through */
	default:
		return false;
	}
}

static const struct reg_default is31fl319x_reg_defaults[] = {
	{ IS31FL319X_CONFIG1, 0x00},
	{ IS31FL319X_CONFIG2, 0x00},
	{ IS31FL319X_PWM(0), 0x00},
	{ IS31FL319X_PWM(1), 0x00},
	{ IS31FL319X_PWM(2), 0x00},
	{ IS31FL319X_PWM(3), 0x00},
	{ IS31FL319X_PWM(4), 0x00},
	{ IS31FL319X_PWM(5), 0x00},
	{ IS31FL319X_PWM(6), 0x00},
	{ IS31FL319X_PWM(7), 0x00},
	{ IS31FL319X_PWM(8), 0x00},
};

static struct regmap_config regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = IS31FL319X_REG_CNT,
	.cache_type = REGCACHE_FLAT,
	.readable_reg = is31fl319x_readable_reg,
	.volatile_reg = is31fl319x_volatile_reg,
	.reg_defaults = is31fl319x_reg_defaults,
	.num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
};

static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
{ /* round down to nearest supported value (range check done by caller) */
	u32 step = microamp / IS31FL319X_CURRENT_STEP;

	return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
		IS31FL319X_CONFIG2_CS_MASK) <<
		IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
}

static inline int is31fl319x_db_to_gain(u32 dezibel)
{ /* round down to nearest supported value (range check done by caller) */
	return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
}

static int is31fl319x_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	struct is31fl319x_chip *is31;
	struct device *dev = &client->dev;
	int err;
	int i = 0;
	u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -EIO;

	is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
	if (!is31)
		return -ENOMEM;

	mutex_init(&is31->lock);

	err = is31fl319x_parse_dt(&client->dev, is31);
	if (err)
		goto free_mutex;

	if (is31->shutdown_gpio) {
		gpiod_direction_output(is31->shutdown_gpio, 0);
		mdelay(5);
		gpiod_direction_output(is31->shutdown_gpio, 1);
	}

	is31->client = client;
	is31->regmap = devm_regmap_init_i2c(client, &regmap_config);
	if (IS_ERR(is31->regmap)) {
		dev_err(&client->dev, "failed to allocate register map\n");
		err = PTR_ERR(is31->regmap);
		goto free_mutex;
	}

	i2c_set_clientdata(client, is31);

	/* check for write-reply from chip (we can't read any registers) */
	err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
	if (err < 0) {
		dev_err(&client->dev, "no response from chip write: err = %d\n",
			err);
		err = -EIO; /* does not answer */
		goto free_mutex;
	}

	/*
	 * Kernel conventions require per-LED led-max-microamp property.
	 * But the chip does not allow to limit individual LEDs.
	 * So we take minimum from all subnodes for safety of hardware.
	 */
	for (i = 0; i < is31->cdef->num_leds; i++)
		if (is31->leds[i].configured &&
		    is31->leds[i].max_microamp < aggregated_led_microamp)
			aggregated_led_microamp = is31->leds[i].max_microamp;

	regmap_write(is31->regmap, IS31FL319X_CONFIG2,
		     is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) |
		     is31fl319x_db_to_gain(is31->audio_gain_db));

	for (i = 0; i < is31->cdef->num_leds; i++) {
		struct is31fl319x_led *led = &is31->leds[i];

		if (!led->configured)
			continue;

		led->chip = is31;
		led->cdev.brightness_set_blocking = is31fl319x_brightness_set;

		err = devm_led_classdev_register(&client->dev, &led->cdev);
		if (err < 0)
			goto free_mutex;
	}

	return 0;

free_mutex:
	mutex_destroy(&is31->lock);
	return err;
}

static int is31fl319x_remove(struct i2c_client *client)
{
	struct is31fl319x_chip *is31 = i2c_get_clientdata(client);

	mutex_destroy(&is31->lock);
	return 0;
}

/*
 * i2c-core (and modalias) requires that id_table be properly filled,
 * even though it is not used for DeviceTree based instantiation.
 */
static const struct i2c_device_id is31fl319x_id[] = {
	{ "is31fl3190" },
	{ "is31fl3191" },
	{ "is31fl3193" },
	{ "is31fl3196" },
	{ "is31fl3199" },
	{ "sn3199" },
	{},
};
MODULE_DEVICE_TABLE(i2c, is31fl319x_id);

static struct i2c_driver is31fl319x_driver = {
	.driver   = {
		.name           = "leds-is31fl319x",
		.of_match_table = of_match_ptr(of_is31fl319x_match),
	},
	.probe    = is31fl319x_probe,
	.remove   = is31fl319x_remove,
	.id_table = is31fl319x_id,
};

module_i2c_driver(is31fl319x_driver);

MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
MODULE_DESCRIPTION("IS31FL319X LED driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
36edc939	1	// SPDX-License-Identifier: GPL-2.0-only
8c40b7d0 NS	2	/*
	3	* Copyright 2015-16 Golden Delicious Computers
	4	*
	5	* Author: Nikolaus Schaller <hns@goldelico.com>
	6	*
8c40b7d0 NS	7	* LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light
8c40b7d0 NS	8	* effect LEDs.
8c40b7d0 NS	9	*/
	10
	11	#include <linux/err.h>
	12	#include <linux/i2c.h>
	13	#include <linux/leds.h>
	14	#include <linux/module.h>
	15	#include <linux/of.h>
	16	#include <linux/of_device.h>
	17	#include <linux/regmap.h>
	18	#include <linux/slab.h>
dddb4e38 GF	19	#include <linux/delay.h>
dddb4e38 GF	20	#include <linux/gpio/consumer.h>
8c40b7d0 NS	21
	22	/* register numbers */
	23	#define IS31FL319X_SHUTDOWN 0x00
	24	#define IS31FL319X_CTRL1 0x01
	25	#define IS31FL319X_CTRL2 0x02
	26	#define IS31FL319X_CONFIG1 0x03
	27	#define IS31FL319X_CONFIG2 0x04
	28	#define IS31FL319X_RAMP_MODE 0x05
	29	#define IS31FL319X_BREATH_MASK 0x06
	30	#define IS31FL319X_PWM(channel) (0x07 + channel)
	31	#define IS31FL319X_DATA_UPDATE 0x10
	32	#define IS31FL319X_T0(channel) (0x11 + channel)
	33	#define IS31FL319X_T123_1 0x1a
	34	#define IS31FL319X_T123_2 0x1b
	35	#define IS31FL319X_T123_3 0x1c
	36	#define IS31FL319X_T4(channel) (0x1d + channel)
	37	#define IS31FL319X_TIME_UPDATE 0x26
	38	#define IS31FL319X_RESET 0xff
	39
	40	#define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1)
	41
	42	#define IS31FL319X_MAX_LEDS 9
	43
	44	/* CS (Current Setting) in CONFIG2 register */
	45	#define IS31FL319X_CONFIG2_CS_SHIFT 4
	46	#define IS31FL319X_CONFIG2_CS_MASK 0x7
	47	#define IS31FL319X_CONFIG2_CS_STEP_REF 12
	48
	49	#define IS31FL319X_CURRENT_MIN ((u32)5000)
	50	#define IS31FL319X_CURRENT_MAX ((u32)40000)
	51	#define IS31FL319X_CURRENT_STEP ((u32)5000)
	52	#define IS31FL319X_CURRENT_DEFAULT ((u32)20000)
	53
	54	/* Audio gain in CONFIG2 register */
	55	#define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21)
	56	#define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3)
	57
	58	/*
	59	* regmap is used as a cache of chip's register space,
	60	* to avoid reading back brightness values from chip,
	61	* which is known to hang.
	62	*/
	63	struct is31fl319x_chip {
	64	const struct is31fl319x_chipdef *cdef;
	65	struct i2c_client *client;
dddb4e38	66	struct gpio_desc *shutdown_gpio;
8c40b7d0 NS	67	struct regmap *regmap;
	68	struct mutex lock;
	69	u32 audio_gain_db;
	70
	71	struct is31fl319x_led {
	72	struct is31fl319x_chip *chip;
	73	struct led_classdev cdev;
	74	u32 max_microamp;
	75	bool configured;
	76	} leds[IS31FL319X_MAX_LEDS];
	77	};
	78
	79	struct is31fl319x_chipdef {
	80	int num_leds;
	81	};
	82
	83	static const struct is31fl319x_chipdef is31fl3190_cdef = {
	84	.num_leds = 1,
	85	};
	86
	87	static const struct is31fl319x_chipdef is31fl3193_cdef = {
	88	.num_leds = 3,
	89	};
	90
	91	static const struct is31fl319x_chipdef is31fl3196_cdef = {
	92	.num_leds = 6,
	93	};
	94
	95	static const struct is31fl319x_chipdef is31fl3199_cdef = {
	96	.num_leds = 9,
	97	};
	98
	99	static const struct of_device_id of_is31fl319x_match[] = {
	100	{ .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, },
	101	{ .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, },
	102	{ .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, },
	103	{ .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, },
	104	{ .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, },
	105	{ .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, },
	106	{ }
	107	};
	108	MODULE_DEVICE_TABLE(of, of_is31fl319x_match);
	109
	110	static int is31fl319x_brightness_set(struct led_classdev *cdev,
	111	enum led_brightness brightness)
	112	{
	113	struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led,
	114	cdev);
	115	struct is31fl319x_chip *is31 = led->chip;
	116	int chan = led - is31->leds;
	117	int ret;
	118	int i;
	119	u8 ctrl1 = 0, ctrl2 = 0;
	120
	121	dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness);
	122
	123	mutex_lock(&is31->lock);
	124
	125	/* update PWM register */
	126	ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness);
	127	if (ret < 0)
	128	goto out;
	129
	130	/* read current brightness of all PWM channels */
131	for (i = 0; i < is31->cdef->num_leds; i++) {
132	unsigned int pwm_value;
133	bool on;
134
135	/*
136	* since neither cdev nor the chip can provide
137	* the current setting, we read from the regmap cache
138	*/
139
140	ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value);
141	dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n",
142	__func__, i, ret, pwm_value);
143	on = ret >= 0 && pwm_value > LED_OFF;
144
145	if (i < 3)
146	ctrl1 \|= on << i; /* 0..2 => bit 0..2 */
147	else if (i < 6)
148	ctrl1 \|= on << (i + 1); /* 3..5 => bit 4..6 */
149	else
150	ctrl2 \|= on << (i - 6); /* 6..8 => bit 0..2 */
151	}
152
153	if (ctrl1 > 0 \|\| ctrl2 > 0) {
154	dev_dbg(&is31->client->dev, "power up %02x %02x\n",
155	ctrl1, ctrl2);
156	regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1);
157	regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2);
158	/* update PWMs */
159	regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00);
160	/* enable chip from shut down */
161	ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01);
162	} else {
163	dev_dbg(&is31->client->dev, "power down\n");
164	/* shut down (no need to clear CTRL1/2) */
165	ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00);
166	}
167
168	out:
169	mutex_unlock(&is31->lock);
170
171	return ret;
172	}
173
174	static int is31fl319x_parse_child_dt(const struct device *dev,
175	const struct device_node *child,
176	struct is31fl319x_led *led)
177	{
178	struct led_classdev *cdev = &led->cdev;
179	int ret;
180
181	if (of_property_read_string(child, "label", &cdev->name))
182	cdev->name = child->name;
183
184	ret = of_property_read_string(child, "linux,default-trigger",
185	&cdev->default_trigger);
186	if (ret < 0 && ret != -EINVAL) /* is optional */
187	return ret;
188
189	led->max_microamp = IS31FL319X_CURRENT_DEFAULT;
190	ret = of_property_read_u32(child, "led-max-microamp",
191	&led->max_microamp);
192	if (!ret) {
193	if (led->max_microamp < IS31FL319X_CURRENT_MIN)
194	return -EINVAL; /* not supported */
195	led->max_microamp = min(led->max_microamp,
196	IS31FL319X_CURRENT_MAX);
197	}
198
199	return 0;
200	}
201
202	static int is31fl319x_parse_dt(struct device *dev,
203	struct is31fl319x_chip *is31)
204	{
205	struct device_node np = dev->of_node, child;
206	const struct of_device_id *of_dev_id;
207	int count;
208	int ret;
209
210	if (!np)
211	return -ENODEV;
212
dddb4e38 GF	213	is31->shutdown_gpio = devm_gpiod_get_optional(dev,
	214	"shutdown",
	215	GPIOD_OUT_HIGH);
	216	if (IS_ERR(is31->shutdown_gpio)) {
	217	ret = PTR_ERR(is31->shutdown_gpio);
	218	dev_err(dev, "Failed to get shutdown gpio: %d\n", ret);
	219	return ret;
	220	}
	221
8c40b7d0 NS	222	of_dev_id = of_match_device(of_is31fl319x_match, dev);
	223	if (!of_dev_id) {
	224	dev_err(dev, "Failed to match device with supported chips\n");
	225	return -EINVAL;
	226	}
	227
	228	is31->cdef = of_dev_id->data;
	229
	230	count = of_get_child_count(np);
	231
	232	dev_dbg(dev, "probe %s with %d leds defined in DT\n",
	233	of_dev_id->compatible, count);
	234
	235	if (!count \|\| count > is31->cdef->num_leds) {
	236	dev_err(dev, "Number of leds defined must be between 1 and %u\n",
	237	is31->cdef->num_leds);
	238	return -ENODEV;
	239	}
	240
	241	for_each_child_of_node(np, child) {
	242	struct is31fl319x_led *led;
	243	u32 reg;
	244
	245	ret = of_property_read_u32(child, "reg", &reg);
	246	if (ret) {
	247	dev_err(dev, "Failed to read led 'reg' property\n");
	248	goto put_child_node;
	249	}
	250
	251	if (reg < 1 \|\| reg > is31->cdef->num_leds) {
	252	dev_err(dev, "invalid led reg %u\n", reg);
	253	ret = -EINVAL;
	254	goto put_child_node;
	255	}
	256
	257	led = &is31->leds[reg - 1];
	258
	259	if (led->configured) {
	260	dev_err(dev, "led %u is already configured\n", reg);
	261	ret = -EINVAL;
	262	goto put_child_node;
	263	}
	264
	265	ret = is31fl319x_parse_child_dt(dev, child, led);
	266	if (ret) {
	267	dev_err(dev, "led %u DT parsing failed\n", reg);
	268	goto put_child_node;
	269	}
	270
	271	led->configured = true;
	272	}
	273
	274	is31->audio_gain_db = 0;
	275	ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db);
	276	if (!ret)
	277	is31->audio_gain_db = min(is31->audio_gain_db,
	278	IS31FL319X_AUDIO_GAIN_DB_MAX);
	279
	280	return 0;
	281
	282	put_child_node:
	283	of_node_put(child);
	284	return ret;
	285	}
286
287	static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg)
288	{ /* we have no readable registers */
289	return false;
290	}
291
292	static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg)
293	{ /* volatile registers are not cached */
294	switch (reg) {
295	case IS31FL319X_DATA_UPDATE:
296	case IS31FL319X_TIME_UPDATE:
297	case IS31FL319X_RESET:
298	return true; /* always write-through */
299	default:
300	return false;
301	}
302	}
303
304	static const struct reg_default is31fl319x_reg_defaults[] = {
305	{ IS31FL319X_CONFIG1, 0x00},
306	{ IS31FL319X_CONFIG2, 0x00},
307	{ IS31FL319X_PWM(0), 0x00},
308	{ IS31FL319X_PWM(1), 0x00},
309	{ IS31FL319X_PWM(2), 0x00},
310	{ IS31FL319X_PWM(3), 0x00},
311	{ IS31FL319X_PWM(4), 0x00},
312	{ IS31FL319X_PWM(5), 0x00},
313	{ IS31FL319X_PWM(6), 0x00},
314	{ IS31FL319X_PWM(7), 0x00},
315	{ IS31FL319X_PWM(8), 0x00},
316	};
317
318	static struct regmap_config regmap_config = {
319	.reg_bits = 8,
320	.val_bits = 8,
321	.max_register = IS31FL319X_REG_CNT,
322	.cache_type = REGCACHE_FLAT,
323	.readable_reg = is31fl319x_readable_reg,
324	.volatile_reg = is31fl319x_volatile_reg,
325	.reg_defaults = is31fl319x_reg_defaults,
326	.num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults),
327	};
328
329	static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp)
330	{ /* round down to nearest supported value (range check done by caller) */
331	u32 step = microamp / IS31FL319X_CURRENT_STEP;
332
333	return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) &
334	IS31FL319X_CONFIG2_CS_MASK) <<
335	IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */
336	}
337
338	static inline int is31fl319x_db_to_gain(u32 dezibel)
339	{ /* round down to nearest supported value (range check done by caller) */
340	return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP;
341	}
342
343	static int is31fl319x_probe(struct i2c_client *client,
344	const struct i2c_device_id *id)
345	{
346	struct is31fl319x_chip *is31;
347	struct device *dev = &client->dev;
8c40b7d0 NS	348	int err;
	349	int i = 0;
	350	u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX;
	351
7d9d60bd	352	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
8c40b7d0 NS	353	return -EIO;
	354
	355	is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL);
	356	if (!is31)
	357	return -ENOMEM;
	358
	359	mutex_init(&is31->lock);
	360
	361	err = is31fl319x_parse_dt(&client->dev, is31);
	362	if (err)
	363	goto free_mutex;
	364
dddb4e38 GF	365	if (is31->shutdown_gpio) {
	366	gpiod_direction_output(is31->shutdown_gpio, 0);
	367	mdelay(5);
	368	gpiod_direction_output(is31->shutdown_gpio, 1);
	369	}
	370
8c40b7d0 NS	371	is31->client = client;
	372	is31->regmap = devm_regmap_init_i2c(client, &regmap_config);
	373	if (IS_ERR(is31->regmap)) {
	374	dev_err(&client->dev, "failed to allocate register map\n");
	375	err = PTR_ERR(is31->regmap);
	376	goto free_mutex;
	377	}
	378
	379	i2c_set_clientdata(client, is31);
	380
	381	/* check for write-reply from chip (we can't read any registers) */
	382	err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00);
	383	if (err < 0) {
	384	dev_err(&client->dev, "no response from chip write: err = %d\n",
	385	err);
	386	err = -EIO; /* does not answer */
	387	goto free_mutex;
	388	}
	389
	390	/*
	391	* Kernel conventions require per-LED led-max-microamp property.
	392	* But the chip does not allow to limit individual LEDs.
	393	* So we take minimum from all subnodes for safety of hardware.
	394	*/
	395	for (i = 0; i < is31->cdef->num_leds; i++)
	396	if (is31->leds[i].configured &&
	397	is31->leds[i].max_microamp < aggregated_led_microamp)
	398	aggregated_led_microamp = is31->leds[i].max_microamp;
	399
	400	regmap_write(is31->regmap, IS31FL319X_CONFIG2,
	401	is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) \|
	402	is31fl319x_db_to_gain(is31->audio_gain_db));
	403
	404	for (i = 0; i < is31->cdef->num_leds; i++) {
	405	struct is31fl319x_led *led = &is31->leds[i];
	406
	407	if (!led->configured)
	408	continue;
	409
	410	led->chip = is31;
	411	led->cdev.brightness_set_blocking = is31fl319x_brightness_set;
	412
	413	err = devm_led_classdev_register(&client->dev, &led->cdev);
	414	if (err < 0)
	415	goto free_mutex;
	416	}
	417
	418	return 0;
	419
	420	free_mutex:
	421	mutex_destroy(&is31->lock);
	422	return err;
	423	}
	424
	425	static int is31fl319x_remove(struct i2c_client *client)
	426	{
	427	struct is31fl319x_chip *is31 = i2c_get_clientdata(client);
	428
	429	mutex_destroy(&is31->lock);
	430	return 0;
	431	}
	432
	433	/*
	434	* i2c-core (and modalias) requires that id_table be properly filled,
435	* even though it is not used for DeviceTree based instantiation.
436	*/
437	static const struct i2c_device_id is31fl319x_id[] = {
438	{ "is31fl3190" },
439	{ "is31fl3191" },
440	{ "is31fl3193" },
441	{ "is31fl3196" },
442	{ "is31fl3199" },
443	{ "sn3199" },
444	{},
445	};
446	MODULE_DEVICE_TABLE(i2c, is31fl319x_id);
447
448	static struct i2c_driver is31fl319x_driver = {
449	.driver = {
450	.name = "leds-is31fl319x",
451	.of_match_table = of_match_ptr(of_is31fl319x_match),
452	},
453	.probe = is31fl319x_probe,
454	.remove = is31fl319x_remove,
455	.id_table = is31fl319x_id,
456	};
457
458	module_i2c_driver(is31fl319x_driver);
459
460	MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
461	MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>");
462	MODULE_DESCRIPTION("IS31FL319X LED driver");
463	MODULE_LICENSE("GPL v2");