[deliverable/linux.git] / drivers / input / misc / pcf8574_keypad.c

/*
 * Driver for a keypad w/16 buttons connected to a PCF8574 I2C I/O expander
 *
 * Copyright 2005-2008 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#define DRV_NAME "pcf8574_keypad"

static const unsigned char pcf8574_kp_btncode[] = {
	[0] = KEY_RESERVED,
	[1] = KEY_ENTER,
	[2] = KEY_BACKSLASH,
	[3] = KEY_0,
	[4] = KEY_RIGHTBRACE,
	[5] = KEY_C,
	[6] = KEY_9,
	[7] = KEY_8,
	[8] = KEY_7,
	[9] = KEY_B,
	[10] = KEY_6,
	[11] = KEY_5,
	[12] = KEY_4,
	[13] = KEY_A,
	[14] = KEY_3,
	[15] = KEY_2,
	[16] = KEY_1
};

struct kp_data {
	unsigned short btncode[ARRAY_SIZE(pcf8574_kp_btncode)];
	struct input_dev *idev;
	struct i2c_client *client;
	char name[64];
	char phys[32];
	unsigned char laststate;
};

static short read_state(struct kp_data *lp)
{
	unsigned char x, y, a, b;

	i2c_smbus_write_byte(lp->client, 240);
	x = 0xF & (~(i2c_smbus_read_byte(lp->client) >> 4));

	i2c_smbus_write_byte(lp->client, 15);
	y = 0xF & (~i2c_smbus_read_byte(lp->client));

	for (a = 0; x > 0; a++)
		x = x >> 1;
	for (b = 0; y > 0; b++)
		y = y >> 1;

	return ((a - 1) * 4) + b;
}

static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id)
{
	struct kp_data *lp = dev_id;
	unsigned char nextstate = read_state(lp);

	if (lp->laststate != nextstate) {
		int key_down = nextstate < ARRAY_SIZE(lp->btncode);
		unsigned short keycode = key_down ?
			lp->btncode[nextstate] : lp->btncode[lp->laststate];

		input_report_key(lp->idev, keycode, key_down);
		input_sync(lp->idev);

		lp->laststate = nextstate;
	}

	return IRQ_HANDLED;
}

static int pcf8574_kp_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	int i, ret;
	struct input_dev *idev;
	struct kp_data *lp;

	if (i2c_smbus_write_byte(client, 240) < 0) {
		dev_err(&client->dev, "probe: write fail\n");
		return -ENODEV;
	}

	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
	if (!lp)
		return -ENOMEM;

	idev = input_allocate_device();
	if (!idev) {
		dev_err(&client->dev, "Can't allocate input device\n");
		ret = -ENOMEM;
		goto fail_allocate;
	}

	lp->idev = idev;
	lp->client = client;

	idev->evbit[0] = BIT_MASK(EV_KEY);
	idev->keycode = lp->btncode;
	idev->keycodesize = sizeof(lp->btncode[0]);
	idev->keycodemax = ARRAY_SIZE(lp->btncode);

	for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
		lp->btncode[i] = pcf8574_kp_btncode[i];
		__set_bit(lp->btncode[i] & KEY_MAX, idev->keybit);
	}

	sprintf(lp->name, DRV_NAME);
	sprintf(lp->phys, "kp_data/input0");

	idev->name = lp->name;
	idev->phys = lp->phys;
	idev->id.bustype = BUS_I2C;
	idev->id.vendor = 0x0001;
	idev->id.product = 0x0001;
	idev->id.version = 0x0100;

	lp->laststate = read_state(lp);

	ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
				   DRV_NAME, lp);
	if (ret) {
		dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
		goto fail_free_device;
	}

	ret = input_register_device(idev);
	if (ret) {
		dev_err(&client->dev, "input_register_device() failed\n");
		goto fail_free_irq;
	}

	i2c_set_clientdata(client, lp);
	return 0;

 fail_free_irq:
	free_irq(client->irq, lp);
 fail_free_device:
	input_free_device(idev);
 fail_allocate:
	kfree(lp);

	return ret;
}

static int pcf8574_kp_remove(struct i2c_client *client)
{
	struct kp_data *lp = i2c_get_clientdata(client);

	free_irq(client->irq, lp);

	input_unregister_device(lp->idev);
	kfree(lp);

	return 0;
}

#ifdef CONFIG_PM
static int pcf8574_kp_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	enable_irq(client->irq);

	return 0;
}

static int pcf8574_kp_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	disable_irq(client->irq);

	return 0;
}

static const struct dev_pm_ops pcf8574_kp_pm_ops = {
	.suspend	= pcf8574_kp_suspend,
	.resume		= pcf8574_kp_resume,
};

#else
# define pcf8574_kp_resume  NULL
# define pcf8574_kp_suspend NULL
#endif

static const struct i2c_device_id pcf8574_kp_id[] = {
	{ DRV_NAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);

static struct i2c_driver pcf8574_kp_driver = {
	.driver = {
		.name  = DRV_NAME,
		.owner = THIS_MODULE,
#ifdef CONFIG_PM
		.pm = &pcf8574_kp_pm_ops,
#endif
	},
	.probe    = pcf8574_kp_probe,
	.remove   = pcf8574_kp_remove,
	.id_table = pcf8574_kp_id,
};

module_i2c_driver(pcf8574_kp_driver);

MODULE_AUTHOR("Michael Hennerich");
MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
MODULE_LICENSE("GPL");
Commit	Line	Data
b91c4be7 BW	1	/*
	2	* Driver for a keypad w/16 buttons connected to a PCF8574 I2C I/O expander
	3	*
	4	* Copyright 2005-2008 Analog Devices Inc.
	5	*
	6	* Licensed under the GPL-2 or later.
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/init.h>
	11	#include <linux/input.h>
	12	#include <linux/interrupt.h>
	13	#include <linux/i2c.h>
	14	#include <linux/slab.h>
	15	#include <linux/workqueue.h>
	16
	17	#define DRV_NAME "pcf8574_keypad"
	18
	19	static const unsigned char pcf8574_kp_btncode[] = {
	20	[0] = KEY_RESERVED,
	21	[1] = KEY_ENTER,
	22	[2] = KEY_BACKSLASH,
	23	[3] = KEY_0,
	24	[4] = KEY_RIGHTBRACE,
	25	[5] = KEY_C,
	26	[6] = KEY_9,
	27	[7] = KEY_8,
	28	[8] = KEY_7,
	29	[9] = KEY_B,
	30	[10] = KEY_6,
	31	[11] = KEY_5,
	32	[12] = KEY_4,
	33	[13] = KEY_A,
	34	[14] = KEY_3,
	35	[15] = KEY_2,
	36	[16] = KEY_1
	37	};
	38
	39	struct kp_data {
	40	unsigned short btncode[ARRAY_SIZE(pcf8574_kp_btncode)];
	41	struct input_dev *idev;
	42	struct i2c_client *client;
	43	char name[64];
	44	char phys[32];
	45	unsigned char laststate;
	46	};
	47
	48	static short read_state(struct kp_data *lp)
	49	{
	50	unsigned char x, y, a, b;
	51
	52	i2c_smbus_write_byte(lp->client, 240);
	53	x = 0xF & (~(i2c_smbus_read_byte(lp->client) >> 4));
	54
	55	i2c_smbus_write_byte(lp->client, 15);
	56	y = 0xF & (~i2c_smbus_read_byte(lp->client));
	57
	58	for (a = 0; x > 0; a++)
	59	x = x >> 1;
	60	for (b = 0; y > 0; b++)
	61	y = y >> 1;
	62
	63	return ((a - 1) * 4) + b;
	64	}
65
66	static irqreturn_t pcf8574_kp_irq_handler(int irq, void *dev_id)
67	{
68	struct kp_data *lp = dev_id;
69	unsigned char nextstate = read_state(lp);
70
71	if (lp->laststate != nextstate) {
0b75f775	72	int key_down = nextstate < ARRAY_SIZE(lp->btncode);
b91c4be7 BW	73	unsigned short keycode = key_down ?
	74	lp->btncode[nextstate] : lp->btncode[lp->laststate];
	75
	76	input_report_key(lp->idev, keycode, key_down);
	77	input_sync(lp->idev);
	78
	79	lp->laststate = nextstate;
	80	}
	81
	82	return IRQ_HANDLED;
	83	}
	84
5298cc4c	85	static int pcf8574_kp_probe(struct i2c_client client, const struct i2c_device_id id)
b91c4be7 BW	86	{
	87	int i, ret;
	88	struct input_dev *idev;
	89	struct kp_data *lp;
	90
	91	if (i2c_smbus_write_byte(client, 240) < 0) {
	92	dev_err(&client->dev, "probe: write fail\n");
	93	return -ENODEV;
	94	}
	95
	96	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
	97	if (!lp)
	98	return -ENOMEM;
	99
	100	idev = input_allocate_device();
	101	if (!idev) {
	102	dev_err(&client->dev, "Can't allocate input device\n");
	103	ret = -ENOMEM;
	104	goto fail_allocate;
	105	}
	106
	107	lp->idev = idev;
	108	lp->client = client;
	109
	110	idev->evbit[0] = BIT_MASK(EV_KEY);
	111	idev->keycode = lp->btncode;
	112	idev->keycodesize = sizeof(lp->btncode[0]);
	113	idev->keycodemax = ARRAY_SIZE(lp->btncode);
	114
	115	for (i = 0; i < ARRAY_SIZE(pcf8574_kp_btncode); i++) {
	116	lp->btncode[i] = pcf8574_kp_btncode[i];
	117	__set_bit(lp->btncode[i] & KEY_MAX, idev->keybit);
	118	}
	119
	120	sprintf(lp->name, DRV_NAME);
	121	sprintf(lp->phys, "kp_data/input0");
	122
	123	idev->name = lp->name;
	124	idev->phys = lp->phys;
	125	idev->id.bustype = BUS_I2C;
	126	idev->id.vendor = 0x0001;
	127	idev->id.product = 0x0001;
	128	idev->id.version = 0x0100;
	129
b91c4be7 BW	130	lp->laststate = read_state(lp);
	131
	132	ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
	133	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	134	DRV_NAME, lp);
	135	if (ret) {
	136	dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
17d01f28 DC	137	goto fail_free_device;
	138	}
	139
	140	ret = input_register_device(idev);
	141	if (ret) {
	142	dev_err(&client->dev, "input_register_device() failed\n");
	143	goto fail_free_irq;
b91c4be7 BW	144	}
	145
	146	i2c_set_clientdata(client, lp);
	147	return 0;
	148
17d01f28 DC	149	fail_free_irq:
	150	free_irq(client->irq, lp);
	151	fail_free_device:
b91c4be7 BW	152	input_free_device(idev);
	153	fail_allocate:
	154	kfree(lp);
	155
	156	return ret;
	157	}
	158
e2619cf7	159	static int pcf8574_kp_remove(struct i2c_client *client)
b91c4be7 BW	160	{
	161	struct kp_data *lp = i2c_get_clientdata(client);
	162
	163	free_irq(client->irq, lp);
	164
	165	input_unregister_device(lp->idev);
	166	kfree(lp);
	167
b91c4be7 BW	168	return 0;
	169	}
	170
	171	#ifdef CONFIG_PM
10ee2ded	172	static int pcf8574_kp_resume(struct device *dev)
b91c4be7	173	{
10ee2ded DT	174	struct i2c_client *client = to_i2c_client(dev);
10ee2ded DT	175
b91c4be7 BW	176	enable_irq(client->irq);
	177
	178	return 0;
	179	}
	180
10ee2ded	181	static int pcf8574_kp_suspend(struct device *dev)
b91c4be7	182	{
10ee2ded DT	183	struct i2c_client *client = to_i2c_client(dev);
10ee2ded DT	184
b91c4be7 BW	185	disable_irq(client->irq);
	186
	187	return 0;
	188	}
10ee2ded DT	189
	190	static const struct dev_pm_ops pcf8574_kp_pm_ops = {
	191	.suspend = pcf8574_kp_suspend,
	192	.resume = pcf8574_kp_resume,
	193	};
	194
b91c4be7 BW	195	#else
	196	# define pcf8574_kp_resume NULL
	197	# define pcf8574_kp_suspend NULL
	198	#endif
	199
	200	static const struct i2c_device_id pcf8574_kp_id[] = {
	201	{ DRV_NAME, 0 },
	202	{ }
	203	};
	204	MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
	205
	206	static struct i2c_driver pcf8574_kp_driver = {
	207	.driver = {
	208	.name = DRV_NAME,
	209	.owner = THIS_MODULE,
10ee2ded DT	210	#ifdef CONFIG_PM
	211	.pm = &pcf8574_kp_pm_ops,
	212	#endif
b91c4be7 BW	213	},
b91c4be7 BW	214	.probe = pcf8574_kp_probe,
1cb0aa88	215	.remove = pcf8574_kp_remove,
b91c4be7 BW	216	.id_table = pcf8574_kp_id,
	217	};
	218
1b92c1cf	219	module_i2c_driver(pcf8574_kp_driver);
b91c4be7 BW	220
	221	MODULE_AUTHOR("Michael Hennerich");
	222	MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
	223	MODULE_LICENSE("GPL");