[linux-2.6-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/module.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/workqueue.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);

struct pca955x_led {
	struct pca955x_chipdef	*chipdef;
	struct i2c_client	*client;
	struct work_struct	work;
	spinlock_t		lock;
	enum led_brightness	brightness;
	struct led_classdev	led_cdev;
	int			led_num;	/* 0 .. 15 potentially */
	char			name[32];
};

/* 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 void pca955x_write_psc(struct i2c_client *client, int n, u8 val)
{
	struct pca955x_led *pca955x = i2c_get_clientdata(client);

	i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
		val);
}

/*
 * 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 void pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
{
	struct pca955x_led *pca955x = i2c_get_clientdata(client);

	i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
		val);
}

/*
 * Write to LED selector register, which determines the source that
 * drives the LED output.
 */
static void pca955x_write_ls(struct i2c_client *client, int n, u8 val)
{
	struct pca955x_led *pca955x = i2c_get_clientdata(client);

	i2c_smbus_write_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
		val);
}

/*
 * Read the LED selector register, which determines the source that
 * drives the LED output.
 */
static u8 pca955x_read_ls(struct i2c_client *client, int n)
{
	struct pca955x_led *pca955x = i2c_get_clientdata(client);

	return (u8) i2c_smbus_read_byte_data(client,
		pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
}

static void pca955x_led_work(struct work_struct *work)
{
	struct pca955x_led *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) */

	pca955x = container_of(work, struct pca955x_led, work);
	chip_ls = pca955x->led_num / 4;
	ls_led = pca955x->led_num % 4;

	ls = pca955x_read_ls(pca955x->client, chip_ls);

	switch (pca955x->brightness) {
	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.
		 */
		pca955x_write_pwm(pca955x->client, 1, 255-pca955x->brightness);
		ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
		break;
	}

	pca955x_write_ls(pca955x->client, chip_ls, ls);
}

static void pca955x_led_set(struct led_classdev *led_cdev, enum led_brightness value)
{
	struct pca955x_led *pca955x;

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

	spin_lock(&pca955x->lock);
	pca955x->brightness = value;

	/*
	 * Must use workqueue for the actual I/O since I2C operations
	 * can sleep.
	 */
	schedule_work(&pca955x->work);

	spin_unlock(&pca955x->lock);
}

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

	chip = &pca955x_chipdefs[id->driver_data];
	adapter = to_i2c_adapter(client->dev.parent);
	pdata = client->dev.platform_data;

	/* 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;
	}

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

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

	if (pdata) {
		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 = kzalloc(sizeof(*pca955x) * chip->bits, GFP_KERNEL);
	if (!pca955x)
		return -ENOMEM;

	i2c_set_clientdata(client, pca955x);

	for (i = 0; i < chip->bits; i++) {
		pca955x[i].chipdef = chip;
		pca955x[i].client = client;
		pca955x[i].led_num = i;

		/* Platform data can specify LED names and default triggers */
		if (pdata) {
			if (pdata->leds[i].name)
				snprintf(pca955x[i].name,
					 sizeof(pca955x[i].name), "pca955x:%s",
					 pdata->leds[i].name);
			if (pdata->leds[i].default_trigger)
				pca955x[i].led_cdev.default_trigger =
					pdata->leds[i].default_trigger;
		} else {
			snprintf(pca955x[i].name, sizeof(pca955x[i].name),
				 "pca955x:%d", i);
		}

		spin_lock_init(&pca955x[i].lock);

		pca955x[i].led_cdev.name = pca955x[i].name;
		pca955x[i].led_cdev.brightness_set = pca955x_led_set;

		INIT_WORK(&pca955x[i].work, pca955x_led_work);

		err = led_classdev_register(&client->dev, &pca955x[i].led_cdev);
		if (err < 0)
			goto exit;
	}

	/* Turn off LEDs */
	for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++)
		pca955x_write_ls(client, i, 0x55);

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

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

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

	return 0;

exit:
	while (i--) {
		led_classdev_unregister(&pca955x[i].led_cdev);
		cancel_work_sync(&pca955x[i].work);
	}

	kfree(pca955x);
	i2c_set_clientdata(client, NULL);

	return err;
}

static int __devexit pca955x_remove(struct i2c_client *client)
{
	struct pca955x_led *pca955x = i2c_get_clientdata(client);
	int i;

	for (i = 0; i < pca955x->chipdef->bits; i++) {
		led_classdev_unregister(&pca955x[i].led_cdev);
		cancel_work_sync(&pca955x[i].work);
	}

	kfree(pca955x);
	i2c_set_clientdata(client, NULL);

	return 0;
}

static struct i2c_driver pca955x_driver = {
	.driver = {
		.name	= "leds-pca955x",
		.owner	= THIS_MODULE,
	},
	.probe	= pca955x_probe,
	.remove	= __devexit_p(pca955x_remove),
	.id_table = pca955x_id,
};

static int __init pca955x_leds_init(void)
{
	return i2c_add_driver(&pca955x_driver);
}

static void __exit pca955x_leds_exit(void)
{
	i2c_del_driver(&pca955x_driver);
}

module_init(pca955x_leds_init);
module_exit(pca955x_leds_exit);

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
	43	#include <linux/module.h>
	44	#include <linux/delay.h>
	45	#include <linux/string.h>
	46	#include <linux/ctype.h>
	47	#include <linux/leds.h>
	48	#include <linux/err.h>
	49	#include <linux/i2c.h>
	50	#include <linux/workqueue.h>
	51
	52	/* LED select registers determine the source that drives LED outputs */
	53	#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
	54	#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
	55	#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
	56	#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
	57
	58	enum pca955x_type {
	59	pca9550,
	60	pca9551,
	61	pca9552,
	62	pca9553,
	63	};
	64
65	struct pca955x_chipdef {
66	int bits;
67	u8 slv_addr; /* 7-bit slave address mask */
68	int slv_addr_shift; /* Number of bits to ignore */
69	};
70
71	static struct pca955x_chipdef pca955x_chipdefs[] = {
72	[pca9550] = {
73	.bits = 2,
74	.slv_addr = /* 110000x */ 0x60,
75	.slv_addr_shift = 1,
76	},
77	[pca9551] = {
78	.bits = 8,
79	.slv_addr = /* 1100xxx */ 0x60,
80	.slv_addr_shift = 3,
81	},
82	[pca9552] = {
83	.bits = 16,
84	.slv_addr = /* 1100xxx */ 0x60,
85	.slv_addr_shift = 3,
86	},
87	[pca9553] = {
88	.bits = 4,
89	.slv_addr = /* 110001x */ 0x62,
90	.slv_addr_shift = 1,
91	},
92	};
93
94	static const struct i2c_device_id pca955x_id[] = {
95	{ "pca9550", pca9550 },
96	{ "pca9551", pca9551 },
97	{ "pca9552", pca9552 },
98	{ "pca9553", pca9553 },
99	{ }
100	};
101	MODULE_DEVICE_TABLE(i2c, pca955x_id);
102
103	struct pca955x_led {
104	struct pca955x_chipdef *chipdef;
105	struct i2c_client *client;
106	struct work_struct work;
107	spinlock_t lock;
108	enum led_brightness brightness;
109	struct led_classdev led_cdev;
110	int led_num; /* 0 .. 15 potentially */
111	char name[32];
112	};
113
114	/* 8 bits per input register */
115	static inline int pca95xx_num_input_regs(int bits)
116	{
117	return (bits + 7) / 8;
118	}
119
120	/* 4 bits per LED selector register */
121	static inline int pca95xx_num_led_regs(int bits)
122	{
123	return (bits + 3) / 4;
124	}
125
126	/*
127	* Return an LED selector register value based on an existing one, with
128	* the appropriate 2-bit state value set for the given LED number (0-3).
129	*/
130	static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
131	{
132	return (oldval & (~(0x3 << (led_num << 1)))) \|
133	((state & 0x3) << (led_num << 1));
134	}
135
136	/*
137	* Write to frequency prescaler register, used to program the
138	* period of the PWM output. period = (PSCx + 1) / 38
139	*/
140	static void pca955x_write_psc(struct i2c_client *client, int n, u8 val)
141	{
142	struct pca955x_led *pca955x = i2c_get_clientdata(client);
143
144	i2c_smbus_write_byte_data(client,
145	pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
146	val);
147	}
148
149	/*
150	* Write to PWM register, which determines the duty cycle of the
151	* output. LED is OFF when the count is less than the value of this
152	* register, and ON when it is greater. If PWMx == 0, LED is always OFF.
153	*
154	* Duty cycle is (256 - PWMx) / 256
155	*/
156	static void pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
157	{
158	struct pca955x_led *pca955x = i2c_get_clientdata(client);
159
160	i2c_smbus_write_byte_data(client,
161	pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
162	val);
163	}
164
165	/*
166	* Write to LED selector register, which determines the source that
167	* drives the LED output.
168	*/
169	static void pca955x_write_ls(struct i2c_client *client, int n, u8 val)
170	{
171	struct pca955x_led *pca955x = i2c_get_clientdata(client);
172
173	i2c_smbus_write_byte_data(client,
174	pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
175	val);
176	}
177
178	/*
179	* Read the LED selector register, which determines the source that
180	* drives the LED output.
181	*/
182	static u8 pca955x_read_ls(struct i2c_client *client, int n)
183	{
184	struct pca955x_led *pca955x = i2c_get_clientdata(client);
185
186	return (u8) i2c_smbus_read_byte_data(client,
187	pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
188	}
189
190	static void pca955x_led_work(struct work_struct *work)
191	{
192	struct pca955x_led *pca955x;
193	u8 ls;
194	int chip_ls; /* which LSx to use (0-3 potentially) */
195	int ls_led; /* which set of bits within LSx to use (0-3) */
196
197	pca955x = container_of(work, struct pca955x_led, work);
198	chip_ls = pca955x->led_num / 4;
199	ls_led = pca955x->led_num % 4;
200
201	ls = pca955x_read_ls(pca955x->client, chip_ls);
202
203	switch (pca955x->brightness) {
204	case LED_FULL:
205	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
206	break;
207	case LED_OFF:
208	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
209	break;
210	case LED_HALF:
211	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
212	break;
213	default:
214	/*
215	* Use PWM1 for all other values. This has the unwanted
216	* side effect of making all LEDs on the chip share the
217	* same brightness level if set to a value other than
218	* OFF, HALF, or FULL. But, this is probably better than
219	* just turning off for all other values.
220	*/
221	pca955x_write_pwm(pca955x->client, 1, 255-pca955x->brightness);
222	ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
223	break;
224	}
225
226	pca955x_write_ls(pca955x->client, chip_ls, ls);
227	}
228
0adaf6e4	229	static void pca955x_led_set(struct led_classdev *led_cdev, enum led_brightness value)
f46e9203 NC	230	{
	231	struct pca955x_led *pca955x;
	232
	233	pca955x = container_of(led_cdev, struct pca955x_led, led_cdev);
	234
	235	spin_lock(&pca955x->lock);
	236	pca955x->brightness = value;
	237
	238	/*
	239	* Must use workqueue for the actual I/O since I2C operations
	240	* can sleep.
	241	*/
	242	schedule_work(&pca955x->work);
	243
	244	spin_unlock(&pca955x->lock);
	245	}
	246
	247	static int __devinit pca955x_probe(struct i2c_client *client,
	248	const struct i2c_device_id *id)
	249	{
	250	struct pca955x_led *pca955x;
f46e9203 NC	251	struct pca955x_chipdef *chip;
	252	struct i2c_adapter *adapter;
	253	struct led_platform_data *pdata;
95bf14bf	254	int i, err;
f46e9203 NC	255
	256	chip = &pca955x_chipdefs[id->driver_data];
	257	adapter = to_i2c_adapter(client->dev.parent);
	258	pdata = client->dev.platform_data;
	259
	260	/* Make sure the slave address / chip type combo given is possible */
	261	if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
	262	chip->slv_addr) {
	263	dev_err(&client->dev, "invalid slave address %02x\n",
	264	client->addr);
	265	return -ENODEV;
	266	}
	267
	268	printk(KERN_INFO "leds-pca955x: Using %s %d-bit LED driver at "
	269	"slave address 0x%02x\n",
	270	id->name, chip->bits, client->addr);
	271
	272	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
	273	return -EIO;
	274
	275	if (pdata) {
	276	if (pdata->num_leds != chip->bits) {
	277	dev_err(&client->dev, "board info claims %d LEDs"
	278	" on a %d-bit chip\n",
	279	pdata->num_leds, chip->bits);
	280	return -ENODEV;
	281	}
	282	}
	283
95bf14bf SW	284	pca955x = kzalloc(sizeof(pca955x) chip->bits, GFP_KERNEL);
	285	if (!pca955x)
	286	return -ENOMEM;
	287
	288	i2c_set_clientdata(client, pca955x);
	289
f46e9203	290	for (i = 0; i < chip->bits; i++) {
95bf14bf SW	291	pca955x[i].chipdef = chip;
	292	pca955x[i].client = client;
	293	pca955x[i].led_num = i;
f46e9203	294
f46e9203 NC	295	/* Platform data can specify LED names and default triggers */
	296	if (pdata) {
	297	if (pdata->leds[i].name)
95bf14bf SW	298	snprintf(pca955x[i].name,
	299	sizeof(pca955x[i].name), "pca955x:%s",
	300	pdata->leds[i].name);
f46e9203	301	if (pdata->leds[i].default_trigger)
95bf14bf	302	pca955x[i].led_cdev.default_trigger =
f46e9203 NC	303	pdata->leds[i].default_trigger;
f46e9203 NC	304	} else {
95bf14bf SW	305	snprintf(pca955x[i].name, sizeof(pca955x[i].name),
95bf14bf SW	306	"pca955x:%d", i);
f46e9203	307	}
f46e9203	308
95bf14bf	309	spin_lock_init(&pca955x[i].lock);
f46e9203	310
95bf14bf SW	311	pca955x[i].led_cdev.name = pca955x[i].name;
95bf14bf SW	312	pca955x[i].led_cdev.brightness_set = pca955x_led_set;
f46e9203	313
95bf14bf	314	INIT_WORK(&pca955x[i].work, pca955x_led_work);
f46e9203	315
95bf14bf SW	316	err = led_classdev_register(&client->dev, &pca955x[i].led_cdev);
	317	if (err < 0)
	318	goto exit;
f46e9203 NC	319	}
	320
	321	/* Turn off LEDs */
	322	for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++)
	323	pca955x_write_ls(client, i, 0x55);
	324
	325	/* PWM0 is used for half brightness or 50% duty cycle */
	326	pca955x_write_pwm(client, 0, 255-LED_HALF);
	327
	328	/* PWM1 is used for variable brightness, default to OFF */
	329	pca955x_write_pwm(client, 1, 0);
	330
	331	/* Set to fast frequency so we do not see flashing */
	332	pca955x_write_psc(client, 0, 0);
	333	pca955x_write_psc(client, 1, 0);
	334
	335	return 0;
95bf14bf	336
f46e9203	337	exit:
95bf14bf SW	338	while (i--) {
	339	led_classdev_unregister(&pca955x[i].led_cdev);
	340	cancel_work_sync(&pca955x[i].work);
	341	}
	342
	343	kfree(pca955x);
	344	i2c_set_clientdata(client, NULL);
	345
f46e9203 NC	346	return err;
	347	}
	348
	349	static int __devexit pca955x_remove(struct i2c_client *client)
	350	{
	351	struct pca955x_led *pca955x = i2c_get_clientdata(client);
f46e9203 NC	352	int i;
f46e9203 NC	353
95bf14bf SW	354	for (i = 0; i < pca955x->chipdef->bits; i++) {
	355	led_classdev_unregister(&pca955x[i].led_cdev);
	356	cancel_work_sync(&pca955x[i].work);
f46e9203 NC	357	}
f46e9203 NC	358
95bf14bf SW	359	kfree(pca955x);
	360	i2c_set_clientdata(client, NULL);
	361
f46e9203 NC	362	return 0;
	363	}
	364
	365	static struct i2c_driver pca955x_driver = {
	366	.driver = {
	367	.name = "leds-pca955x",
	368	.owner = THIS_MODULE,
	369	},
	370	.probe = pca955x_probe,
	371	.remove = __devexit_p(pca955x_remove),
	372	.id_table = pca955x_id,
	373	};
	374
	375	static int __init pca955x_leds_init(void)
	376	{
	377	return i2c_add_driver(&pca955x_driver);
	378	}
	379
	380	static void __exit pca955x_leds_exit(void)
	381	{
	382	i2c_del_driver(&pca955x_driver);
	383	}
	384
	385	module_init(pca955x_leds_init);
	386	module_exit(pca955x_leds_exit);
	387
	388	MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
	389	MODULE_DESCRIPTION("PCA955x LED driver");
	390	MODULE_LICENSE("GPL v2");