[linux-block.git] / drivers / leds / leds-pca955x.c

/*
 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
 *
 * Author: Nate Case <ncase@xes-inc.com>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * LED driver for various PCA955x I2C LED drivers
 *
 * Supported devices:
 *
 *	Device		Description		7-bit slave address
 *	------		-----------		-------------------
 *	PCA9550		2-bit driver		0x60 .. 0x61
 *	PCA9551		8-bit driver		0x60 .. 0x67
 *	PCA9552		16-bit driver		0x60 .. 0x67
 *	PCA9553/01	4-bit driver		0x62
 *	PCA9553/02	4-bit driver		0x63
 *
 * Philips PCA955x LED driver chips follow a register map as shown below:
 *
 *	Control Register		Description
 *	----------------		-----------
 *	0x0				Input register 0
 *					..
 *	NUM_INPUT_REGS - 1		Last Input register X
 *
 *	NUM_INPUT_REGS			Frequency prescaler 0
 *	NUM_INPUT_REGS + 1		PWM register 0
 *	NUM_INPUT_REGS + 2		Frequency prescaler 1
 *	NUM_INPUT_REGS + 3		PWM register 1
 *
 *	NUM_INPUT_REGS + 4		LED selector 0
 *	NUM_INPUT_REGS + 4
 *	    + NUM_LED_REGS - 1		Last LED selector
 *
 *  where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
 *  bits the chip supports.
 */

#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/string.h>

#include <dt-bindings/leds/leds-pca955x.h>

/* LED select registers determine the source that drives LED outputs */
#define PCA955X_LS_LED_ON	0x0	/* Output LOW */
#define PCA955X_LS_LED_OFF	0x1	/* Output HI-Z */
#define PCA955X_LS_BLINK0	0x2	/* Blink at PWM0 rate */
#define PCA955X_LS_BLINK1	0x3	/* Blink at PWM1 rate */

#define PCA955X_GPIO_INPUT	LED_OFF
#define PCA955X_GPIO_HIGH	LED_OFF
#define PCA955X_GPIO_LOW	LED_FULL

enum pca955x_type {
	pca9550,
	pca9551,
	pca9552,
	pca9553,
};

struct pca955x_chipdef {
	int			bits;
	u8			slv_addr;	/* 7-bit slave address mask */
	int			slv_addr_shift;	/* Number of bits to ignore */
};

static struct pca955x_chipdef pca955x_chipdefs[] = {
	[pca9550] = {
		.bits		= 2,
		.slv_addr	= /* 110000x */ 0x60,
		.slv_addr_shift	= 1,
	},
	[pca9551] = {
		.bits		= 8,
		.slv_addr	= /* 1100xxx */ 0x60,
		.slv_addr_shift	= 3,
	},
	[pca9552] = {
		.bits		= 16,
		.slv_addr	= /* 1100xxx */ 0x60,
		.slv_addr_shift	= 3,
	},
	[pca9553] = {
		.bits		= 4,
		.slv_addr	= /* 110001x */ 0x62,
		.slv_addr_shift	= 1,
	},
};

static const struct i2c_device_id pca955x_id[] = {
	{ "pca9550", pca9550 },
	{ "pca9551", pca9551 },
	{ "pca9552", pca9552 },
	{ "pca9553", pca9553 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pca955x_id);

struct pca955x {
	struct mutex lock;
	struct pca955x_led *leds;
	struct pca955x_chipdef	*chipdef;
	struct i2c_client	*client;
#ifdef CONFIG_LEDS_PCA955X_GPIO
	struct gpio_chip gpio;
#endif
};

struct pca955x_led {
	struct pca955x	*pca955x;
	struct led_classdev	led_cdev;
	int			led_num;	/* 0 .. 15 potentially */
	char			name[32];
	u32			type;
	const char		*default_trigger;
};

struct pca955x_platform_data {
	struct pca955x_led	*leds;
	int			num_leds;
};

/* 8 bits per input register */
static inline int pca95xx_num_input_regs(int bits)
{
	return (bits + 7) / 8;
}

/* 4 bits per LED selector register */
static inline int pca95xx_num_led_regs(int bits)
{
	return (bits + 3)  / 4;
}

/*
 * Return an LED selector register value based on an existing one, with
 * the appropriate 2-bit state value set for the given LED number (0-3).
 */
static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
{
	return (oldval & (~(0x3 << (led_num << 1)))) |
		((state & 0x3) << (led_num << 1));
}

/*
 * Write to frequency prescaler register, used to program the
 * period of the PWM output.  period = (PSCx + 1) / 38
 */
static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
{
	struct pca955x *pca955x = i2c_get_clientdata(client);
	int ret;

	ret = i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
		val);
	if (ret < 0)
		dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
			__func__, n, val, ret);
	return ret;
}

/*
 * Write to PWM register, which determines the duty cycle of the
 * output.  LED is OFF when the count is less than the value of this
 * register, and ON when it is greater.  If PWMx == 0, LED is always OFF.
 *
 * Duty cycle is (256 - PWMx) / 256
 */
static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
{
	struct pca955x *pca955x = i2c_get_clientdata(client);
	int ret;

	ret = i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
		val);
	if (ret < 0)
		dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
			__func__, n, val, ret);
	return ret;
}

/*
 * Write to LED selector register, which determines the source that
 * drives the LED output.
 */
static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
{
	struct pca955x *pca955x = i2c_get_clientdata(client);
	int ret;

	ret = i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
		val);
	if (ret < 0)
		dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
			__func__, n, val, ret);
	return ret;
}

/*
 * Read the LED selector register, which determines the source that
 * drives the LED output.
 */
static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
{
	struct pca955x *pca955x = i2c_get_clientdata(client);
	int ret;

	ret = i2c_smbus_read_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
	if (ret < 0) {
		dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
			__func__, n, ret);
		return ret;
	}
	*val = (u8)ret;
	return 0;
}

static int pca955x_led_set(struct led_classdev *led_cdev,
			    enum led_brightness value)
{
	struct pca955x_led *pca955x_led;
	struct pca955x *pca955x;
	u8 ls;
	int chip_ls;	/* which LSx to use (0-3 potentially) */
	int ls_led;	/* which set of bits within LSx to use (0-3) */
	int ret;

	pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
	pca955x = pca955x_led->pca955x;

	chip_ls = pca955x_led->led_num / 4;
	ls_led = pca955x_led->led_num % 4;

	mutex_lock(&pca955x->lock);

	ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
	if (ret)
		goto out;

	switch (value) {
	case LED_FULL:
		ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
		break;
	case LED_OFF:
		ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
		break;
	case LED_HALF:
		ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
		break;
	default:
		/*
		 * Use PWM1 for all other values.  This has the unwanted
		 * side effect of making all LEDs on the chip share the
		 * same brightness level if set to a value other than
		 * OFF, HALF, or FULL.  But, this is probably better than
		 * just turning off for all other values.
		 */
		ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
		if (ret)
			goto out;
		ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
		break;
	}

	ret = pca955x_write_ls(pca955x->client, chip_ls, ls);

out:
	mutex_unlock(&pca955x->lock);

	return ret;
}

#ifdef CONFIG_LEDS_PCA955X_GPIO
/*
 * Read the INPUT register, which contains the state of LEDs.
 */
static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
{
	int ret = i2c_smbus_read_byte_data(client, n);

	if (ret < 0) {
		dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
			__func__, n, ret);
		return ret;
	}
	*val = (u8)ret;
	return 0;

}

static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
{
	struct pca955x *pca955x = gpiochip_get_data(gc);
	struct pca955x_led *led = &pca955x->leds[offset];

	if (led->type == PCA955X_TYPE_GPIO)
		return 0;

	return -EBUSY;
}

static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
			     int val)
{
	struct pca955x *pca955x = gpiochip_get_data(gc);
	struct pca955x_led *led = &pca955x->leds[offset];

	if (val)
		return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);

	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
}

static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
				   int val)
{
	pca955x_set_value(gc, offset, val);
}

static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
{
	struct pca955x *pca955x = gpiochip_get_data(gc);
	struct pca955x_led *led = &pca955x->leds[offset];
	u8 reg = 0;

	/* There is nothing we can do about errors */
	pca955x_read_input(pca955x->client, led->led_num / 8, &reg);

	return !!(reg & (1 << (led->led_num % 8)));
}

static int pca955x_gpio_direction_input(struct gpio_chip *gc,
					unsigned int offset)
{
	struct pca955x *pca955x = gpiochip_get_data(gc);
	struct pca955x_led *led = &pca955x->leds[offset];

	/* To use as input ensure pin is not driven. */
	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
}

static int pca955x_gpio_direction_output(struct gpio_chip *gc,
					 unsigned int offset, int val)
{
	return pca955x_set_value(gc, offset, val);
}
#endif /* CONFIG_LEDS_PCA955X_GPIO */

static struct pca955x_platform_data *
pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
{
	struct pca955x_platform_data *pdata;
	struct fwnode_handle *child;
	int count;

	count = device_get_child_node_count(&client->dev);
	if (!count || count > chip->bits)
		return ERR_PTR(-ENODEV);

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

	pdata->leds = devm_kcalloc(&client->dev,
				   chip->bits, sizeof(struct pca955x_led),
				   GFP_KERNEL);
	if (!pdata->leds)
		return ERR_PTR(-ENOMEM);

	device_for_each_child_node(&client->dev, child) {
		const char *name;
		u32 reg;
		int res;

		res = fwnode_property_read_u32(child, "reg", &reg);
		if ((res != 0) || (reg >= chip->bits))
			continue;

		res = fwnode_property_read_string(child, "label", &name);
		if ((res != 0) && is_of_node(child))
			name = to_of_node(child)->name;

		snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
			 "%s", name);

		pdata->leds[reg].type = PCA955X_TYPE_LED;
		fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
		fwnode_property_read_string(child, "linux,default-trigger",
					&pdata->leds[reg].default_trigger);
	}

	pdata->num_leds = chip->bits;

	return pdata;
}

static const struct of_device_id of_pca955x_match[] = {
	{ .compatible = "nxp,pca9550", .data = (void *)pca9550 },
	{ .compatible = "nxp,pca9551", .data = (void *)pca9551 },
	{ .compatible = "nxp,pca9552", .data = (void *)pca9552 },
	{ .compatible = "nxp,pca9553", .data = (void *)pca9553 },
	{},
};
MODULE_DEVICE_TABLE(of, of_pca955x_match);

static int pca955x_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	struct pca955x *pca955x;
	struct pca955x_led *pca955x_led;
	struct pca955x_chipdef *chip;
	struct i2c_adapter *adapter;
	int i, err;
	struct pca955x_platform_data *pdata;
	int ngpios = 0;

	chip = &pca955x_chipdefs[id->driver_data];
	adapter = to_i2c_adapter(client->dev.parent);
	pdata = dev_get_platdata(&client->dev);
	if (!pdata) {
		pdata =	pca955x_get_pdata(client, chip);
		if (IS_ERR(pdata))
			return PTR_ERR(pdata);
	}

	/* Make sure the slave address / chip type combo given is possible */
	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
	    chip->slv_addr) {
		dev_err(&client->dev, "invalid slave address %02x\n",
				client->addr);
		return -ENODEV;
	}

	dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
			"slave address 0x%02x\n",
			client->name, chip->bits, client->addr);

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -EIO;

	if (pdata->num_leds != chip->bits) {
		dev_err(&client->dev,
			"board info claims %d LEDs on a %d-bit chip\n",
			pdata->num_leds, chip->bits);
		return -ENODEV;
	}

	pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
	if (!pca955x)
		return -ENOMEM;

	pca955x->leds = devm_kcalloc(&client->dev,
			chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
	if (!pca955x->leds)
		return -ENOMEM;

	i2c_set_clientdata(client, pca955x);

	mutex_init(&pca955x->lock);
	pca955x->client = client;
	pca955x->chipdef = chip;

	for (i = 0; i < chip->bits; i++) {
		pca955x_led = &pca955x->leds[i];
		pca955x_led->led_num = i;
		pca955x_led->pca955x = pca955x;
		pca955x_led->type = pdata->leds[i].type;

		switch (pca955x_led->type) {
		case PCA955X_TYPE_NONE:
			break;
		case PCA955X_TYPE_GPIO:
			ngpios++;
			break;
		case PCA955X_TYPE_LED:
			/*
			 * Platform data can specify LED names and
			 * default triggers
			 */
			if (pdata->leds[i].name[0] == '\0')
				snprintf(pdata->leds[i].name,
					sizeof(pdata->leds[i].name), "%d", i);

			snprintf(pca955x_led->name,
				sizeof(pca955x_led->name), "pca955x:%s",
				pdata->leds[i].name);

			if (pdata->leds[i].default_trigger)
				pca955x_led->led_cdev.default_trigger =
					pdata->leds[i].default_trigger;

			pca955x_led->led_cdev.name = pca955x_led->name;
			pca955x_led->led_cdev.brightness_set_blocking =
				pca955x_led_set;

			err = devm_led_classdev_register(&client->dev,
							&pca955x_led->led_cdev);
			if (err)
				return err;

			/* Turn off LED */
			err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
			if (err)
				return err;
		}
	}

	/* PWM0 is used for half brightness or 50% duty cycle */
	err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
	if (err)
		return err;

	/* PWM1 is used for variable brightness, default to OFF */
	err = pca955x_write_pwm(client, 1, 0);
	if (err)
		return err;

	/* Set to fast frequency so we do not see flashing */
	err = pca955x_write_psc(client, 0, 0);
	if (err)
		return err;
	err = pca955x_write_psc(client, 1, 0);
	if (err)
		return err;

#ifdef CONFIG_LEDS_PCA955X_GPIO
	if (ngpios) {
		pca955x->gpio.label = "gpio-pca955x";
		pca955x->gpio.direction_input = pca955x_gpio_direction_input;
		pca955x->gpio.direction_output = pca955x_gpio_direction_output;
		pca955x->gpio.set = pca955x_gpio_set_value;
		pca955x->gpio.get = pca955x_gpio_get_value;
		pca955x->gpio.request = pca955x_gpio_request_pin;
		pca955x->gpio.can_sleep = 1;
		pca955x->gpio.base = -1;
		pca955x->gpio.ngpio = ngpios;
		pca955x->gpio.parent = &client->dev;
		pca955x->gpio.owner = THIS_MODULE;

		err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
					     pca955x);
		if (err) {
			/* Use data->gpio.dev as a flag for freeing gpiochip */
			pca955x->gpio.parent = NULL;
			dev_warn(&client->dev, "could not add gpiochip\n");
			return err;
		}
		dev_info(&client->dev, "gpios %i...%i\n",
			 pca955x->gpio.base, pca955x->gpio.base +
			 pca955x->gpio.ngpio - 1);
	}
#endif

	return 0;
}

static struct i2c_driver pca955x_driver = {
	.driver = {
		.name	= "leds-pca955x",
		.of_match_table = of_pca955x_match,
	},
	.probe	= pca955x_probe,
	.id_table = pca955x_id,
};

module_i2c_driver(pca955x_driver);

MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
MODULE_DESCRIPTION("PCA955x LED driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
f46e9203 NC	1	/*
	2	* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
	3	*
	4	* Author: Nate Case <ncase@xes-inc.com>
	5	*
	6	* This file is subject to the terms and conditions of version 2 of
	7	* the GNU General Public License. See the file COPYING in the main
	8	* directory of this archive for more details.
	9	*
	10	* LED driver for various PCA955x I2C LED drivers
	11	*
	12	* Supported devices:
	13	*
	14	* Device Description 7-bit slave address
	15	* ------ ----------- -------------------
	16	* PCA9550 2-bit driver 0x60 .. 0x61
	17	* PCA9551 8-bit driver 0x60 .. 0x67
	18	* PCA9552 16-bit driver 0x60 .. 0x67
	19	* PCA9553/01 4-bit driver 0x62
	20	* PCA9553/02 4-bit driver 0x63
	21	*
	22	* Philips PCA955x LED driver chips follow a register map as shown below:
	23	*
	24	* Control Register Description
	25	* ---------------- -----------
	26	* 0x0 Input register 0
	27	* ..
	28	* NUM_INPUT_REGS - 1 Last Input register X
	29	*
	30	* NUM_INPUT_REGS Frequency prescaler 0
	31	* NUM_INPUT_REGS + 1 PWM register 0
	32	* NUM_INPUT_REGS + 2 Frequency prescaler 1
	33	* NUM_INPUT_REGS + 3 PWM register 1
	34	*
	35	* NUM_INPUT_REGS + 4 LED selector 0
	36	* NUM_INPUT_REGS + 4
	37	* + NUM_LED_REGS - 1 Last LED selector
	38	*
	39	* where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
	40	* bits the chip supports.
	41	*/
	42
f46e9203	43	#include <linux/ctype.h>
ed1f4b96	44	#include <linux/delay.h>
f46e9203	45	#include <linux/err.h>
ed1f4b96	46	#include <linux/gpio.h>
f46e9203	47	#include <linux/i2c.h>
ed1f4b96 CLG	48	#include <linux/leds.h>
ed1f4b96 CLG	49	#include <linux/module.h>
ed1f4b96	50	#include <linux/of.h>
967f69de	51	#include <linux/property.h>
5a0e3ad6	52	#include <linux/slab.h>
ed1f4b96	53	#include <linux/string.h>
f46e9203	54
561099a1 CLG	55	#include <dt-bindings/leds/leds-pca955x.h>
561099a1 CLG	56
f46e9203 NC	57	/* LED select registers determine the source that drives LED outputs */
	58	#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
	59	#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
	60	#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
	61	#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
	62
52ca7d0f AJ	63	#define PCA955X_GPIO_INPUT LED_OFF
	64	#define PCA955X_GPIO_HIGH LED_OFF
	65	#define PCA955X_GPIO_LOW LED_FULL
	66
f46e9203 NC	67	enum pca955x_type {
	68	pca9550,
	69	pca9551,
	70	pca9552,
	71	pca9553,
	72	};
	73
	74	struct pca955x_chipdef {
	75	int bits;
	76	u8 slv_addr; /* 7-bit slave address mask */
	77	int slv_addr_shift; /* Number of bits to ignore */
	78	};
	79
	80	static struct pca955x_chipdef pca955x_chipdefs[] = {
	81	[pca9550] = {
	82	.bits = 2,
	83	.slv_addr = /* 110000x */ 0x60,
	84	.slv_addr_shift = 1,
	85	},
	86	[pca9551] = {
	87	.bits = 8,
	88	.slv_addr = /* 1100xxx */ 0x60,
	89	.slv_addr_shift = 3,
	90	},
	91	[pca9552] = {
	92	.bits = 16,
	93	.slv_addr = /* 1100xxx */ 0x60,
	94	.slv_addr_shift = 3,
	95	},
	96	[pca9553] = {
	97	.bits = 4,
	98	.slv_addr = /* 110001x */ 0x62,
	99	.slv_addr_shift = 1,
	100	},
	101	};
	102
	103	static const struct i2c_device_id pca955x_id[] = {
	104	{ "pca9550", pca9550 },
	105	{ "pca9551", pca9551 },
	106	{ "pca9552", pca9552 },
	107	{ "pca9553", pca9553 },
	108	{ }
	109	};
	110	MODULE_DEVICE_TABLE(i2c, pca955x_id);
	111
e7e11d8b AS	112	struct pca955x {
	113	struct mutex lock;
	114	struct pca955x_led *leds;
f46e9203 NC	115	struct pca955x_chipdef *chipdef;
f46e9203 NC	116	struct i2c_client *client;
561099a1 CLG	117	#ifdef CONFIG_LEDS_PCA955X_GPIO
	118	struct gpio_chip gpio;
	119	#endif
e7e11d8b AS	120	};
	121
	122	struct pca955x_led {
	123	struct pca955x *pca955x;
f46e9203 NC	124	struct led_classdev led_cdev;
	125	int led_num; /* 0 .. 15 potentially */
	126	char name[32];
561099a1	127	u32 type;
ed1f4b96 CLG	128	const char *default_trigger;
	129	};
	130
	131	struct pca955x_platform_data {
	132	struct pca955x_led *leds;
	133	int num_leds;
f46e9203 NC	134	};
	135
	136	/* 8 bits per input register */
	137	static inline int pca95xx_num_input_regs(int bits)
	138	{
	139	return (bits + 7) / 8;
	140	}
	141
	142	/* 4 bits per LED selector register */
	143	static inline int pca95xx_num_led_regs(int bits)
	144	{
	145	return (bits + 3) / 4;
	146	}
	147
	148	/*
	149	* Return an LED selector register value based on an existing one, with
	150	* the appropriate 2-bit state value set for the given LED number (0-3).
	151	*/
	152	static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
	153	{
	154	return (oldval & (~(0x3 << (led_num << 1)))) \|
	155	((state & 0x3) << (led_num << 1));
	156	}
	157
	158	/*
	159	* Write to frequency prescaler register, used to program the
	160	* period of the PWM output. period = (PSCx + 1) / 38
	161	*/
1591caf2	162	static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
f46e9203	163	{
e7e11d8b	164	struct pca955x *pca955x = i2c_get_clientdata(client);
1591caf2	165	int ret;
f46e9203	166
1591caf2	167	ret = i2c_smbus_write_byte_data(client,
f46e9203 NC	168	pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
f46e9203 NC	169	val);
1591caf2 CLG	170	if (ret < 0)
	171	dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
	172	__func__, n, val, ret);
	173	return ret;
f46e9203 NC	174	}
	175
	176	/*
	177	* Write to PWM register, which determines the duty cycle of the
	178	* output. LED is OFF when the count is less than the value of this
	179	* register, and ON when it is greater. If PWMx == 0, LED is always OFF.
	180	*
	181	* Duty cycle is (256 - PWMx) / 256
	182	*/
1591caf2	183	static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
f46e9203	184	{
e7e11d8b	185	struct pca955x *pca955x = i2c_get_clientdata(client);
1591caf2	186	int ret;
f46e9203	187
1591caf2	188	ret = i2c_smbus_write_byte_data(client,
f46e9203 NC	189	pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
f46e9203 NC	190	val);
1591caf2 CLG	191	if (ret < 0)
	192	dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
	193	__func__, n, val, ret);
	194	return ret;
f46e9203 NC	195	}
	196
	197	/*
	198	* Write to LED selector register, which determines the source that
	199	* drives the LED output.
	200	*/
1591caf2	201	static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
f46e9203	202	{
e7e11d8b	203	struct pca955x *pca955x = i2c_get_clientdata(client);
1591caf2	204	int ret;
f46e9203	205
1591caf2	206	ret = i2c_smbus_write_byte_data(client,
f46e9203 NC	207	pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
f46e9203 NC	208	val);
1591caf2 CLG	209	if (ret < 0)
	210	dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
	211	__func__, n, val, ret);
	212	return ret;
f46e9203 NC	213	}
	214
	215	/*
	216	* Read the LED selector register, which determines the source that
	217	* drives the LED output.
	218	*/
1591caf2	219	static int pca955x_read_ls(struct i2c_client client, int n, u8 val)
f46e9203	220	{
e7e11d8b	221	struct pca955x *pca955x = i2c_get_clientdata(client);
1591caf2	222	int ret;
f46e9203	223
1591caf2	224	ret = i2c_smbus_read_byte_data(client,
f46e9203	225	pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
1591caf2 CLG	226	if (ret < 0) {
	227	dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
	228	__func__, n, ret);
	229	return ret;
	230	}
	231	*val = (u8)ret;
	232	return 0;
f46e9203 NC	233	}
f46e9203 NC	234
c3482b82 AL	235	static int pca955x_led_set(struct led_classdev *led_cdev,
c3482b82 AL	236	enum led_brightness value)
f46e9203	237	{
e7e11d8b AS	238	struct pca955x_led *pca955x_led;
e7e11d8b AS	239	struct pca955x *pca955x;
f46e9203 NC	240	u8 ls;
	241	int chip_ls; /* which LSx to use (0-3 potentially) */
	242	int ls_led; /* which set of bits within LSx to use (0-3) */
1591caf2	243	int ret;
f46e9203	244
c3482b82	245	pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
e7e11d8b AS	246	pca955x = pca955x_led->pca955x;
	247
	248	chip_ls = pca955x_led->led_num / 4;
	249	ls_led = pca955x_led->led_num % 4;
	250
	251	mutex_lock(&pca955x->lock);
f46e9203	252
1591caf2 CLG	253	ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
	254	if (ret)
	255	goto out;
f46e9203	256
c3482b82	257	switch (value) {
f46e9203 NC	258	case LED_FULL:
	259	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
	260	break;
	261	case LED_OFF:
	262	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
	263	break;
	264	case LED_HALF:
	265	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
	266	break;
	267	default:
	268	/*
	269	* Use PWM1 for all other values. This has the unwanted
	270	* side effect of making all LEDs on the chip share the
	271	* same brightness level if set to a value other than
	272	* OFF, HALF, or FULL. But, this is probably better than
	273	* just turning off for all other values.
	274	*/
1591caf2 CLG	275	ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
	276	if (ret)
	277	goto out;
f46e9203 NC	278	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
	279	break;
	280	}
	281
1591caf2	282	ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
e7e11d8b	283
1591caf2	284	out:
e7e11d8b	285	mutex_unlock(&pca955x->lock);
f46e9203	286
1591caf2	287	return ret;
f46e9203 NC	288	}
f46e9203 NC	289
561099a1 CLG	290	#ifdef CONFIG_LEDS_PCA955X_GPIO
	291	/*
	292	* Read the INPUT register, which contains the state of LEDs.
	293	*/
1591caf2	294	static int pca955x_read_input(struct i2c_client client, int n, u8 val)
561099a1	295	{
1591caf2 CLG	296	int ret = i2c_smbus_read_byte_data(client, n);
	297
	298	if (ret < 0) {
	299	dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
	300	__func__, n, ret);
	301	return ret;
	302	}
	303	*val = (u8)ret;
	304	return 0;
	305
561099a1 CLG	306	}
	307
	308	static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
	309	{
	310	struct pca955x *pca955x = gpiochip_get_data(gc);
	311	struct pca955x_led *led = &pca955x->leds[offset];
	312
	313	if (led->type == PCA955X_TYPE_GPIO)
	314	return 0;
	315
	316	return -EBUSY;
	317	}
	318
1591caf2 CLG	319	static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
1591caf2 CLG	320	int val)
561099a1 CLG	321	{
	322	struct pca955x *pca955x = gpiochip_get_data(gc);
	323	struct pca955x_led *led = &pca955x->leds[offset];
	324
	325	if (val)
52ca7d0f AJ	326	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
	327
	328	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
1591caf2 CLG	329	}
	330
	331	static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
	332	int val)
	333	{
	334	pca955x_set_value(gc, offset, val);
561099a1 CLG	335	}
	336
	337	static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
	338	{
	339	struct pca955x *pca955x = gpiochip_get_data(gc);
	340	struct pca955x_led *led = &pca955x->leds[offset];
1591caf2 CLG	341	u8 reg = 0;
	342
	343	/* There is nothing we can do about errors */
	344	pca955x_read_input(pca955x->client, led->led_num / 8, &reg);
561099a1 CLG	345
	346	return !!(reg & (1 << (led->led_num % 8)));
	347	}
	348
	349	static int pca955x_gpio_direction_input(struct gpio_chip *gc,
	350	unsigned int offset)
	351	{
52ca7d0f AJ	352	struct pca955x *pca955x = gpiochip_get_data(gc);
	353	struct pca955x_led *led = &pca955x->leds[offset];
	354
	355	/* To use as input ensure pin is not driven. */
	356	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
561099a1 CLG	357	}
	358
	359	static int pca955x_gpio_direction_output(struct gpio_chip *gc,
	360	unsigned int offset, int val)
	361	{
1591caf2	362	return pca955x_set_value(gc, offset, val);
561099a1 CLG	363	}
	364	#endif /* CONFIG_LEDS_PCA955X_GPIO */
	365
ed1f4b96	366	static struct pca955x_platform_data *
967f69de	367	pca955x_get_pdata(struct i2c_client client, struct pca955x_chipdef chip)
ed1f4b96	368	{
ed1f4b96	369	struct pca955x_platform_data *pdata;
967f69de	370	struct fwnode_handle *child;
ed1f4b96 CLG	371	int count;
ed1f4b96 CLG	372
967f69de	373	count = device_get_child_node_count(&client->dev);
ed1f4b96 CLG	374	if (!count \|\| count > chip->bits)
	375	return ERR_PTR(-ENODEV);
	376
	377	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
	378	if (!pdata)
	379	return ERR_PTR(-ENOMEM);
	380
a86854d0 KC	381	pdata->leds = devm_kcalloc(&client->dev,
a86854d0 KC	382	chip->bits, sizeof(struct pca955x_led),
ed1f4b96 CLG	383	GFP_KERNEL);
	384	if (!pdata->leds)
	385	return ERR_PTR(-ENOMEM);
	386
967f69de	387	device_for_each_child_node(&client->dev, child) {
ed1f4b96 CLG	388	const char *name;
	389	u32 reg;
	390	int res;
	391
967f69de	392	res = fwnode_property_read_u32(child, "reg", &reg);
ed1f4b96 CLG	393	if ((res != 0) \|\| (reg >= chip->bits))
	394	continue;
	395
967f69de AS	396	res = fwnode_property_read_string(child, "label", &name);
	397	if ((res != 0) && is_of_node(child))
	398	name = to_of_node(child)->name;
ed1f4b96 CLG	399
	400	snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
	401	"%s", name);
	402
561099a1	403	pdata->leds[reg].type = PCA955X_TYPE_LED;
967f69de AS	404	fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
967f69de AS	405	fwnode_property_read_string(child, "linux,default-trigger",
ed1f4b96 CLG	406	&pdata->leds[reg].default_trigger);
	407	}
	408
	409	pdata->num_leds = chip->bits;
	410
	411	return pdata;
	412	}
	413
	414	static const struct of_device_id of_pca955x_match[] = {
	415	{ .compatible = "nxp,pca9550", .data = (void *)pca9550 },
	416	{ .compatible = "nxp,pca9551", .data = (void *)pca9551 },
	417	{ .compatible = "nxp,pca9552", .data = (void *)pca9552 },
	418	{ .compatible = "nxp,pca9553", .data = (void *)pca9553 },
	419	{},
	420	};
ed1f4b96	421	MODULE_DEVICE_TABLE(of, of_pca955x_match);
ed1f4b96	422
98ea1ea2	423	static int pca955x_probe(struct i2c_client *client,
f46e9203 NC	424	const struct i2c_device_id *id)
f46e9203 NC	425	{
e7e11d8b AS	426	struct pca955x *pca955x;
e7e11d8b AS	427	struct pca955x_led *pca955x_led;
f46e9203 NC	428	struct pca955x_chipdef *chip;
f46e9203 NC	429	struct i2c_adapter *adapter;
95bf14bf	430	int i, err;
ed1f4b96	431	struct pca955x_platform_data *pdata;
561099a1	432	int ngpios = 0;
f46e9203	433
5b6cd445	434	chip = &pca955x_chipdefs[id->driver_data];
f46e9203	435	adapter = to_i2c_adapter(client->dev.parent);
87aae1ea	436	pdata = dev_get_platdata(&client->dev);
ed1f4b96	437	if (!pdata) {
967f69de	438	pdata = pca955x_get_pdata(client, chip);
ed1f4b96 CLG	439	if (IS_ERR(pdata))
	440	return PTR_ERR(pdata);
	441	}
f46e9203 NC	442
	443	/* Make sure the slave address / chip type combo given is possible */
	444	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
	445	chip->slv_addr) {
	446	dev_err(&client->dev, "invalid slave address %02x\n",
	447	client->addr);
	448	return -ENODEV;
	449	}
	450
b40b0c17	451	dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
f46e9203	452	"slave address 0x%02x\n",
44b3e31d	453	client->name, chip->bits, client->addr);
f46e9203	454
aace34c0	455	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
f46e9203 NC	456	return -EIO;
f46e9203 NC	457
ed1f4b96 CLG	458	if (pdata->num_leds != chip->bits) {
	459	dev_err(&client->dev,
	460	"board info claims %d LEDs on a %d-bit chip\n",
	461	pdata->num_leds, chip->bits);
	462	return -ENODEV;
f46e9203 NC	463	}
f46e9203 NC	464
73759f6a	465	pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
95bf14bf SW	466	if (!pca955x)
	467	return -ENOMEM;
	468
a86854d0 KC	469	pca955x->leds = devm_kcalloc(&client->dev,
a86854d0 KC	470	chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
73759f6a BW	471	if (!pca955x->leds)
73759f6a BW	472	return -ENOMEM;
e7e11d8b	473
95bf14bf SW	474	i2c_set_clientdata(client, pca955x);
95bf14bf SW	475
e7e11d8b AS	476	mutex_init(&pca955x->lock);
	477	pca955x->client = client;
	478	pca955x->chipdef = chip;
	479
f46e9203	480	for (i = 0; i < chip->bits; i++) {
e7e11d8b AS	481	pca955x_led = &pca955x->leds[i];
	482	pca955x_led->led_num = i;
	483	pca955x_led->pca955x = pca955x;
561099a1 CLG	484	pca955x_led->type = pdata->leds[i].type;
	485
	486	switch (pca955x_led->type) {
	487	case PCA955X_TYPE_NONE:
	488	break;
	489	case PCA955X_TYPE_GPIO:
	490	ngpios++;
	491	break;
	492	case PCA955X_TYPE_LED:
	493	/*
	494	* Platform data can specify LED names and
	495	* default triggers
	496	*/
390c97dc JA	497	if (pdata->leds[i].name[0] == '\0')
	498	snprintf(pdata->leds[i].name,
	499	sizeof(pdata->leds[i].name), "%d", i);
	500
	501	snprintf(pca955x_led->name,
	502	sizeof(pca955x_led->name), "pca955x:%s",
	503	pdata->leds[i].name);
	504
f46e9203	505	if (pdata->leds[i].default_trigger)
e7e11d8b	506	pca955x_led->led_cdev.default_trigger =
f46e9203	507	pdata->leds[i].default_trigger;
f46e9203	508
561099a1 CLG	509	pca955x_led->led_cdev.name = pca955x_led->name;
	510	pca955x_led->led_cdev.brightness_set_blocking =
	511	pca955x_led_set;
f46e9203	512
561099a1 CLG	513	err = devm_led_classdev_register(&client->dev,
	514	&pca955x_led->led_cdev);
	515	if (err)
	516	return err;
f46e9203	517
561099a1	518	/* Turn off LED */
1591caf2 CLG	519	err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
	520	if (err)
	521	return err;
561099a1 CLG	522	}
561099a1 CLG	523	}
f46e9203 NC	524
f46e9203 NC	525	/* PWM0 is used for half brightness or 50% duty cycle */
1591caf2 CLG	526	err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
	527	if (err)
	528	return err;
f46e9203 NC	529
f46e9203 NC	530	/* PWM1 is used for variable brightness, default to OFF */
1591caf2 CLG	531	err = pca955x_write_pwm(client, 1, 0);
	532	if (err)
	533	return err;
f46e9203 NC	534
f46e9203 NC	535	/* Set to fast frequency so we do not see flashing */
1591caf2 CLG	536	err = pca955x_write_psc(client, 0, 0);
	537	if (err)
	538	return err;
	539	err = pca955x_write_psc(client, 1, 0);
	540	if (err)
	541	return err;
f46e9203	542
561099a1 CLG	543	#ifdef CONFIG_LEDS_PCA955X_GPIO
	544	if (ngpios) {
	545	pca955x->gpio.label = "gpio-pca955x";
	546	pca955x->gpio.direction_input = pca955x_gpio_direction_input;
	547	pca955x->gpio.direction_output = pca955x_gpio_direction_output;
	548	pca955x->gpio.set = pca955x_gpio_set_value;
	549	pca955x->gpio.get = pca955x_gpio_get_value;
	550	pca955x->gpio.request = pca955x_gpio_request_pin;
	551	pca955x->gpio.can_sleep = 1;
	552	pca955x->gpio.base = -1;
	553	pca955x->gpio.ngpio = ngpios;
	554	pca955x->gpio.parent = &client->dev;
	555	pca955x->gpio.owner = THIS_MODULE;
	556
	557	err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
	558	pca955x);
	559	if (err) {
	560	/* Use data->gpio.dev as a flag for freeing gpiochip */
	561	pca955x->gpio.parent = NULL;
	562	dev_warn(&client->dev, "could not add gpiochip\n");
	563	return err;
	564	}
	565	dev_info(&client->dev, "gpios %i...%i\n",
	566	pca955x->gpio.base, pca955x->gpio.base +
	567	pca955x->gpio.ngpio - 1);
	568	}
	569	#endif
	570
f46e9203	571	return 0;
f46e9203 NC	572	}
	573
	574	static struct i2c_driver pca955x_driver = {
	575	.driver = {
	576	.name = "leds-pca955x",
967f69de	577	.of_match_table = of_pca955x_match,
f46e9203 NC	578	},
f46e9203 NC	579	.probe = pca955x_probe,
f46e9203 NC	580	.id_table = pca955x_id,
	581	};
	582
09a0d183	583	module_i2c_driver(pca955x_driver);
f46e9203 NC	584
	585	MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
	586	MODULE_DESCRIPTION("PCA955x LED driver");
	587	MODULE_LICENSE("GPL v2");