[net-next-2.6.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 __devinit 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;

	input_set_drvdata(idev, lp);

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

	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_irq;
	}

	i2c_set_clientdata(client, lp);
	return 0;

 fail_irq:
	input_unregister_device(idev);
 fail_register:
	input_set_drvdata(idev, NULL);
	input_free_device(idev);
 fail_allocate:
	kfree(lp);

	return ret;
}

static int __devexit 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 i2c_client *client)
{
	enable_irq(client->irq);

	return 0;
}

static int pcf8574_kp_suspend(struct i2c_client *client, pm_message_t mesg)
{
	disable_irq(client->irq);

	return 0;
}
#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,
	},
	.probe    = pcf8574_kp_probe,
	.remove   = __devexit_p(pcf8574_kp_remove),
	.suspend  = pcf8574_kp_suspend,
	.resume   = pcf8574_kp_resume,
	.id_table = pcf8574_kp_id,
};

static int __init pcf8574_kp_init(void)
{
	return i2c_add_driver(&pcf8574_kp_driver);
}
module_init(pcf8574_kp_init);

static void __exit pcf8574_kp_exit(void)
{
	i2c_del_driver(&pcf8574_kp_driver);
}
module_exit(pcf8574_kp_exit);

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) {
72	int key_down = nextstate <= ARRAY_SIZE(lp->btncode);
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
85	static int __devinit pcf8574_kp_probe(struct i2c_client client, const struct i2c_device_id id)
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
130	input_set_drvdata(idev, lp);
131
132	ret = input_register_device(idev);
133	if (ret) {
134	dev_err(&client->dev, "input_register_device() failed\n");
135	goto fail_register;
136	}
137
138	lp->laststate = read_state(lp);
139
140	ret = request_threaded_irq(client->irq, NULL, pcf8574_kp_irq_handler,
141	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
142	DRV_NAME, lp);
143	if (ret) {
144	dev_err(&client->dev, "IRQ %d is not free\n", client->irq);
145	goto fail_irq;
146	}
147
148	i2c_set_clientdata(client, lp);
149	return 0;
150
151	fail_irq:
152	input_unregister_device(idev);
153	fail_register:
154	input_set_drvdata(idev, NULL);
155	input_free_device(idev);
156	fail_allocate:
157	kfree(lp);
158
159	return ret;
160	}
161
162	static int __devexit pcf8574_kp_remove(struct i2c_client *client)
163	{
164	struct kp_data *lp = i2c_get_clientdata(client);
165
166	free_irq(client->irq, lp);
167
168	input_unregister_device(lp->idev);
169	kfree(lp);
170
b91c4be7 BW	171	return 0;
	172	}
	173
	174	#ifdef CONFIG_PM
	175	static int pcf8574_kp_resume(struct i2c_client *client)
	176	{
	177	enable_irq(client->irq);
	178
	179	return 0;
	180	}
	181
	182	static int pcf8574_kp_suspend(struct i2c_client *client, pm_message_t mesg)
	183	{
	184	disable_irq(client->irq);
	185
	186	return 0;
	187	}
	188	#else
	189	# define pcf8574_kp_resume NULL
	190	# define pcf8574_kp_suspend NULL
	191	#endif
	192
	193	static const struct i2c_device_id pcf8574_kp_id[] = {
	194	{ DRV_NAME, 0 },
	195	{ }
	196	};
	197	MODULE_DEVICE_TABLE(i2c, pcf8574_kp_id);
	198
	199	static struct i2c_driver pcf8574_kp_driver = {
	200	.driver = {
	201	.name = DRV_NAME,
	202	.owner = THIS_MODULE,
	203	},
	204	.probe = pcf8574_kp_probe,
	205	.remove = __devexit_p(pcf8574_kp_remove),
	206	.suspend = pcf8574_kp_suspend,
	207	.resume = pcf8574_kp_resume,
	208	.id_table = pcf8574_kp_id,
	209	};
	210
	211	static int __init pcf8574_kp_init(void)
	212	{
	213	return i2c_add_driver(&pcf8574_kp_driver);
	214	}
	215	module_init(pcf8574_kp_init);
	216
	217	static void __exit pcf8574_kp_exit(void)
	218	{
	219	i2c_del_driver(&pcf8574_kp_driver);
	220	}
	221	module_exit(pcf8574_kp_exit);
	222
	223	MODULE_AUTHOR("Michael Hennerich");
	224	MODULE_DESCRIPTION("Keypad input driver for 16 keys connected to PCF8574");
	225	MODULE_LICENSE("GPL");