Release 4.14 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/acpi.h>
#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_device.h>
#include <linux/of.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 */


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);


static const struct acpi_device_id pca955x_acpi_ids[] = {
	{ "PCA9550",  pca9550 },
	{ "PCA9551",  pca9551 },
	{ "PCA9552",  pca9552 },
	{ "PCA9553",  pca9553 },
	{ }
};
MODULE_DEVICE_TABLE(acpi, pca955x_acpi_ids);


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;
}

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/* 4 bits per LED selector register */


static inline int pca95xx_num_led_regs(int bits)
{
	return (bits + 3)  / 4;
}

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/*
 * 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));
}

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/*
 * 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;
}

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/*
 * 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;
}

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/*
 * 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;
}

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/*
 * 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;
}

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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;
}

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#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;

}

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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;
}

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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, LED_FULL);
	else
		return pca955x_led_set(&led->led_cdev, LED_OFF);
}

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

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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)));
}

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static int pca955x_gpio_direction_input(struct gpio_chip *gc,
					unsigned int offset)
{
	/* To use as input ensure pin is not driven */
	return pca955x_set_value(gc, offset, 0);
}

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

#if IS_ENABLED(CONFIG_OF)

static struct pca955x_platform_data *

pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
{
	struct device_node *np = client->dev.of_node;
	struct device_node *child;
	struct pca955x_platform_data *pdata;
	int count;

	count = of_get_child_count(np);
	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_kzalloc(&client->dev,
				   sizeof(struct pca955x_led) * chip->bits,
				   GFP_KERNEL);
	if (!pdata->leds)
		return ERR_PTR(-ENOMEM);

	for_each_child_of_node(np, child) {
		const char *name;
		u32 reg;
		int res;

		res = of_property_read_u32(child, "reg", &reg);
		if ((res != 0) || (reg >= chip->bits))
			continue;

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

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

		pdata->leds[reg].type = PCA955X_TYPE_LED;
		of_property_read_u32(child, "type", &pdata->leds[reg].type);
		of_property_read_string(child, "linux,default-trigger",
					&pdata->leds[reg].default_trigger);
	}

	pdata->num_leds = chip->bits;

	return pdata;
}

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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);
#else

static struct pca955x_platform_data *

pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
{
	return ERR_PTR(-ENODEV);
}
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#endif



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;

	if (id) {
		chip = &pca955x_chipdefs[id->driver_data];
	} else {
		const struct acpi_device_id *acpi_id;

		acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev);
		if (!acpi_id)
			return -ENODEV;
		chip = &pca955x_chipdefs[acpi_id->driver_data];
	}
	adapter = to_i2c_adapter(client->dev.parent);
	pdata = dev_get_platdata(&client->dev);
	if (!pdata) {
		pdata =	pca955x_pdata_of_init(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_kzalloc(&client->dev,
			sizeof(*pca955x_led) * chip->bits, 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Nate Case
317
37.21%
1
7.14%
Cédric Le Goater
307
36.03%
4
28.57%
Alexander Stein
77
9.04%
1
7.14%
Tin Huynh
48
5.63%
2
14.29%
Sven Wegener
45
5.28%
1
7.14%
Jacek Anaszewski
33
3.87%
1
7.14%
Bryan Wu
14
1.64%
1
7.14%
Sachin Kamat
6
0.70%
1
7.14%
Jingoo Han
4
0.47%
1
7.14%
Andrew Lunn
1
0.12%
1
7.14%
Total
852
100.00%
14
100.00%


static struct i2c_driver pca955x_driver = {
	.driver = {
		.name	= "leds-pca955x",
		.acpi_match_table = ACPI_PTR(pca955x_acpi_ids),
		.of_match_table = of_match_ptr(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");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Cédric Le Goater
1293
48.72%
4
25.00%
Nate Case
1009
38.02%
1
6.25%
Alexander Stein
131
4.94%
1
6.25%
Tin Huynh
101
3.81%
2
12.50%
Sven Wegener
45
1.70%
1
6.25%
Jacek Anaszewski
33
1.24%
1
6.25%
Andrew Lunn
15
0.57%
1
6.25%
Bryan Wu
14
0.53%
1
6.25%
Sachin Kamat
6
0.23%
1
6.25%
Jingoo Han
4
0.15%
1
6.25%
Axel Lin
2
0.08%
1
6.25%
Tejun Heo
1
0.04%
1
6.25%
Total
2654
100.00%
16
100.00%
Directory: drivers/leds

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