[deliverable/linux.git] / drivers / i2c / busses / i2c-taos-evm.c

/*
 * Driver for the TAOS evaluation modules
 * These devices include an I2C master which can be controlled over the
 * serial port.
 *
 * Copyright (C) 2007 Jean Delvare <jdelvare@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

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

#define TAOS_BUFFER_SIZE	63

#define TAOS_STATE_INIT		0
#define TAOS_STATE_IDLE		1
#define TAOS_STATE_EOFF		2
#define TAOS_STATE_RECV		3

#define TAOS_CMD_RESET		0x12
#define TAOS_CMD_ECHO_ON	'+'
#define TAOS_CMD_ECHO_OFF	'-'

static DECLARE_WAIT_QUEUE_HEAD(wq);

struct taos_data {
	struct i2c_adapter adapter;
	struct i2c_client *client;
	int state;
	u8 addr;		/* last used address */
	unsigned char buffer[TAOS_BUFFER_SIZE];
	unsigned int pos;	/* position inside the buffer */
};

/* TAOS TSL2550 EVM */
static struct i2c_board_info tsl2550_info = {
	I2C_BOARD_INFO("tsl2550", 0x39),
};

/* Instantiate i2c devices based on the adapter name */
static struct i2c_client *taos_instantiate_device(struct i2c_adapter *adapter)
{
	if (!strncmp(adapter->name, "TAOS TSL2550 EVM", 16)) {
		dev_info(&adapter->dev, "Instantiating device %s at 0x%02x\n",
			tsl2550_info.type, tsl2550_info.addr);
		return i2c_new_device(adapter, &tsl2550_info);
	}

	return NULL;
}

static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
			   unsigned short flags, char read_write, u8 command,
			   int size, union i2c_smbus_data *data)
{
	struct serio *serio = adapter->algo_data;
	struct taos_data *taos = serio_get_drvdata(serio);
	char *p;

	/* Encode our transaction. "@" is for the device address, "$" for the
	   SMBus command and "#" for the data. */
	p = taos->buffer;

	/* The device remembers the last used address, no need to send it
	   again if it's the same */
	if (addr != taos->addr)
		p += sprintf(p, "@%02X", addr);

	switch (size) {
	case I2C_SMBUS_BYTE:
		if (read_write == I2C_SMBUS_WRITE)
			sprintf(p, "$#%02X", command);
		else
			sprintf(p, "$");
		break;
	case I2C_SMBUS_BYTE_DATA:
		if (read_write == I2C_SMBUS_WRITE)
			sprintf(p, "$%02X#%02X", command, data->byte);
		else
			sprintf(p, "$%02X", command);
		break;
	default:
		dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
		return -EOPNOTSUPP;
	}

	/* Send the transaction to the TAOS EVM */
	dev_dbg(&adapter->dev, "Command buffer: %s\n", taos->buffer);
	for (p = taos->buffer; *p; p++)
		serio_write(serio, *p);

	taos->addr = addr;

	/* Start the transaction and read the answer */
	taos->pos = 0;
	taos->state = TAOS_STATE_RECV;
	serio_write(serio, read_write == I2C_SMBUS_WRITE ? '>' : '<');
	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
					 msecs_to_jiffies(150));
	if (taos->state != TAOS_STATE_IDLE
	 || taos->pos != 5) {
		dev_err(&adapter->dev, "Transaction timeout (pos=%d)\n",
			taos->pos);
		return -EIO;
	}
	dev_dbg(&adapter->dev, "Answer buffer: %s\n", taos->buffer);

	/* Interpret the returned string */
	p = taos->buffer + 1;
	p[3] = '\0';
	if (!strcmp(p, "NAK"))
		return -ENODEV;

	if (read_write == I2C_SMBUS_WRITE) {
		if (!strcmp(p, "ACK"))
			return 0;
	} else {
		if (p[0] == 'x') {
			data->byte = simple_strtol(p + 1, NULL, 16);
			return 0;
		}
	}

	return -EIO;
}

static u32 taos_smbus_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA;
}

static const struct i2c_algorithm taos_algorithm = {
	.smbus_xfer	= taos_smbus_xfer,
	.functionality	= taos_smbus_func,
};

static irqreturn_t taos_interrupt(struct serio *serio, unsigned char data,
				  unsigned int flags)
{
	struct taos_data *taos = serio_get_drvdata(serio);

	switch (taos->state) {
	case TAOS_STATE_INIT:
		taos->buffer[taos->pos++] = data;
		if (data == ':'
		 || taos->pos == TAOS_BUFFER_SIZE - 1) {
			taos->buffer[taos->pos] = '\0';
			taos->state = TAOS_STATE_IDLE;
			wake_up_interruptible(&wq);
		}
		break;
	case TAOS_STATE_EOFF:
		taos->state = TAOS_STATE_IDLE;
		wake_up_interruptible(&wq);
		break;
	case TAOS_STATE_RECV:
		taos->buffer[taos->pos++] = data;
		if (data == ']') {
			taos->buffer[taos->pos] = '\0';
			taos->state = TAOS_STATE_IDLE;
			wake_up_interruptible(&wq);
		}
		break;
	}

	return IRQ_HANDLED;
}

/* Extract the adapter name from the buffer received after reset.
   The buffer is modified and a pointer inside the buffer is returned. */
static char *taos_adapter_name(char *buffer)
{
	char *start, *end;

	start = strstr(buffer, "TAOS ");
	if (!start)
		return NULL;

	end = strchr(start, '\r');
	if (!end)
		return NULL;
	*end = '\0';

	return start;
}

static int taos_connect(struct serio *serio, struct serio_driver *drv)
{
	struct taos_data *taos;
	struct i2c_adapter *adapter;
	char *name;
	int err;

	taos = kzalloc(sizeof(struct taos_data), GFP_KERNEL);
	if (!taos) {
		err = -ENOMEM;
		goto exit;
	}
	taos->state = TAOS_STATE_INIT;
	serio_set_drvdata(serio, taos);

	err = serio_open(serio, drv);
	if (err)
		goto exit_kfree;

	adapter = &taos->adapter;
	adapter->owner = THIS_MODULE;
	adapter->algo = &taos_algorithm;
	adapter->algo_data = serio;
	adapter->dev.parent = &serio->dev;

	/* Reset the TAOS evaluation module to identify it */
	serio_write(serio, TAOS_CMD_RESET);
	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
					 msecs_to_jiffies(2000));

	if (taos->state != TAOS_STATE_IDLE) {
		err = -ENODEV;
		dev_err(&serio->dev, "TAOS EVM reset failed (state=%d, "
			"pos=%d)\n", taos->state, taos->pos);
		goto exit_close;
	}

	name = taos_adapter_name(taos->buffer);
	if (!name) {
		err = -ENODEV;
		dev_err(&serio->dev, "TAOS EVM identification failed\n");
		goto exit_close;
	}
	strlcpy(adapter->name, name, sizeof(adapter->name));

	/* Turn echo off for better performance */
	taos->state = TAOS_STATE_EOFF;
	serio_write(serio, TAOS_CMD_ECHO_OFF);

	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
					 msecs_to_jiffies(250));
	if (taos->state != TAOS_STATE_IDLE) {
		err = -ENODEV;
		dev_err(&serio->dev, "TAOS EVM echo off failed "
			"(state=%d)\n", taos->state);
		goto exit_close;
	}

	err = i2c_add_adapter(adapter);
	if (err)
		goto exit_close;
	dev_info(&serio->dev, "Connected to TAOS EVM\n");

	taos->client = taos_instantiate_device(adapter);
	return 0;

 exit_close:
	serio_close(serio);
 exit_kfree:
	kfree(taos);
 exit:
	return err;
}

static void taos_disconnect(struct serio *serio)
{
	struct taos_data *taos = serio_get_drvdata(serio);

	if (taos->client)
		i2c_unregister_device(taos->client);
	i2c_del_adapter(&taos->adapter);
	serio_close(serio);
	kfree(taos);

	dev_info(&serio->dev, "Disconnected from TAOS EVM\n");
}

static struct serio_device_id taos_serio_ids[] = {
	{
		.type	= SERIO_RS232,
		.proto	= SERIO_TAOSEVM,
		.id	= SERIO_ANY,
		.extra	= SERIO_ANY,
	},
	{ 0 }
};
MODULE_DEVICE_TABLE(serio, taos_serio_ids);

static struct serio_driver taos_drv = {
	.driver		= {
		.name	= "taos-evm",
	},
	.description	= "TAOS evaluation module driver",
	.id_table	= taos_serio_ids,
	.connect	= taos_connect,
	.disconnect	= taos_disconnect,
	.interrupt	= taos_interrupt,
};

static int __init taos_init(void)
{
	return serio_register_driver(&taos_drv);
}

static void __exit taos_exit(void)
{
	serio_unregister_driver(&taos_drv);
}

MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("TAOS evaluation module driver");
MODULE_LICENSE("GPL");

module_init(taos_init);
module_exit(taos_exit);
Commit	Line	Data
b9cdad74 JD	1	/*
	2	* Driver for the TAOS evaluation modules
	3	* These devices include an I2C master which can be controlled over the
	4	* serial port.
	5	*
7c81c60f	6	* Copyright (C) 2007 Jean Delvare <jdelvare@suse.de>
b9cdad74 JD	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; version 2 of the License.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	20	*/
	21
	22	#include <linux/delay.h>
	23	#include <linux/module.h>
	24	#include <linux/slab.h>
	25	#include <linux/interrupt.h>
	26	#include <linux/input.h>
	27	#include <linux/serio.h>
	28	#include <linux/init.h>
	29	#include <linux/i2c.h>
	30
	31	#define TAOS_BUFFER_SIZE 63
	32
	33	#define TAOS_STATE_INIT 0
	34	#define TAOS_STATE_IDLE 1
27693ce5	35	#define TAOS_STATE_EOFF 2
b9cdad74 JD	36	#define TAOS_STATE_RECV 3
	37
	38	#define TAOS_CMD_RESET 0x12
27693ce5 JD	39	#define TAOS_CMD_ECHO_ON '+'
27693ce5 JD	40	#define TAOS_CMD_ECHO_OFF '-'
b9cdad74 JD	41
	42	static DECLARE_WAIT_QUEUE_HEAD(wq);
	43
	44	struct taos_data {
	45	struct i2c_adapter adapter;
	46	struct i2c_client *client;
	47	int state;
	48	u8 addr; /* last used address */
	49	unsigned char buffer[TAOS_BUFFER_SIZE];
	50	unsigned int pos; /* position inside the buffer */
	51	};
	52
	53	/* TAOS TSL2550 EVM */
	54	static struct i2c_board_info tsl2550_info = {
	55	I2C_BOARD_INFO("tsl2550", 0x39),
b9cdad74 JD	56	};
	57
	58	/* Instantiate i2c devices based on the adapter name */
	59	static struct i2c_client taos_instantiate_device(struct i2c_adapter adapter)
	60	{
	61	if (!strncmp(adapter->name, "TAOS TSL2550 EVM", 16)) {
	62	dev_info(&adapter->dev, "Instantiating device %s at 0x%02x\n",
3760f736	63	tsl2550_info.type, tsl2550_info.addr);
b9cdad74 JD	64	return i2c_new_device(adapter, &tsl2550_info);
	65	}
	66
	67	return NULL;
	68	}
	69
	70	static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
	71	unsigned short flags, char read_write, u8 command,
	72	int size, union i2c_smbus_data *data)
	73	{
	74	struct serio *serio = adapter->algo_data;
	75	struct taos_data *taos = serio_get_drvdata(serio);
	76	char *p;
	77
	78	/* Encode our transaction. "@" is for the device address, "$" for the
	79	SMBus command and "#" for the data. */
	80	p = taos->buffer;
	81
	82	/* The device remembers the last used address, no need to send it
	83	again if it's the same */
	84	if (addr != taos->addr)
	85	p += sprintf(p, "@%02X", addr);
	86
	87	switch (size) {
	88	case I2C_SMBUS_BYTE:
	89	if (read_write == I2C_SMBUS_WRITE)
	90	sprintf(p, "$#%02X", command);
	91	else
	92	sprintf(p, "$");
	93	break;
	94	case I2C_SMBUS_BYTE_DATA:
	95	if (read_write == I2C_SMBUS_WRITE)
	96	sprintf(p, "$%02X#%02X", command, data->byte);
	97	else
	98	sprintf(p, "$%02X", command);
	99	break;
	100	default:
ac7fc4fb JD	101	dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
ac7fc4fb JD	102	return -EOPNOTSUPP;
b9cdad74 JD	103	}
	104
	105	/* Send the transaction to the TAOS EVM */
	106	dev_dbg(&adapter->dev, "Command buffer: %s\n", taos->buffer);
27693ce5 JD	107	for (p = taos->buffer; *p; p++)
	108	serio_write(serio, *p);
	109
b9cdad74 JD	110	taos->addr = addr;
	111
	112	/* Start the transaction and read the answer */
	113	taos->pos = 0;
	114	taos->state = TAOS_STATE_RECV;
	115	serio_write(serio, read_write == I2C_SMBUS_WRITE ? '>' : '<');
	116	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
	117	msecs_to_jiffies(150));
	118	if (taos->state != TAOS_STATE_IDLE
27693ce5	119	\|\| taos->pos != 5) {
b9cdad74 JD	120	dev_err(&adapter->dev, "Transaction timeout (pos=%d)\n",
	121	taos->pos);
	122	return -EIO;
	123	}
	124	dev_dbg(&adapter->dev, "Answer buffer: %s\n", taos->buffer);
	125
	126	/* Interpret the returned string */
27693ce5	127	p = taos->buffer + 1;
b9cdad74 JD	128	p[3] = '\0';
	129	if (!strcmp(p, "NAK"))
	130	return -ENODEV;
	131
	132	if (read_write == I2C_SMBUS_WRITE) {
	133	if (!strcmp(p, "ACK"))
	134	return 0;
	135	} else {
	136	if (p[0] == 'x') {
	137	data->byte = simple_strtol(p + 1, NULL, 16);
	138	return 0;
	139	}
	140	}
	141
	142	return -EIO;
	143	}
	144
	145	static u32 taos_smbus_func(struct i2c_adapter *adapter)
	146	{
	147	return I2C_FUNC_SMBUS_BYTE \| I2C_FUNC_SMBUS_BYTE_DATA;
	148	}
	149
	150	static const struct i2c_algorithm taos_algorithm = {
	151	.smbus_xfer = taos_smbus_xfer,
	152	.functionality = taos_smbus_func,
	153	};
	154
	155	static irqreturn_t taos_interrupt(struct serio *serio, unsigned char data,
	156	unsigned int flags)
	157	{
	158	struct taos_data *taos = serio_get_drvdata(serio);
	159
	160	switch (taos->state) {
	161	case TAOS_STATE_INIT:
	162	taos->buffer[taos->pos++] = data;
	163	if (data == ':'
	164	\|\| taos->pos == TAOS_BUFFER_SIZE - 1) {
	165	taos->buffer[taos->pos] = '\0';
	166	taos->state = TAOS_STATE_IDLE;
	167	wake_up_interruptible(&wq);
	168	}
	169	break;
27693ce5 JD	170	case TAOS_STATE_EOFF:
	171	taos->state = TAOS_STATE_IDLE;
	172	wake_up_interruptible(&wq);
b9cdad74 JD	173	break;
	174	case TAOS_STATE_RECV:
	175	taos->buffer[taos->pos++] = data;
	176	if (data == ']') {
	177	taos->buffer[taos->pos] = '\0';
	178	taos->state = TAOS_STATE_IDLE;
	179	wake_up_interruptible(&wq);
	180	}
	181	break;
	182	}
	183
	184	return IRQ_HANDLED;
	185	}
	186
	187	/* Extract the adapter name from the buffer received after reset.
	188	The buffer is modified and a pointer inside the buffer is returned. */
	189	static char taos_adapter_name(char buffer)
	190	{
	191	char start, end;
	192
	193	start = strstr(buffer, "TAOS ");
	194	if (!start)
	195	return NULL;
	196
	197	end = strchr(start, '\r');
	198	if (!end)
	199	return NULL;
	200	*end = '\0';
	201
	202	return start;
	203	}
	204
	205	static int taos_connect(struct serio serio, struct serio_driver drv)
	206	{
	207	struct taos_data *taos;
	208	struct i2c_adapter *adapter;
	209	char *name;
	210	int err;
	211
	212	taos = kzalloc(sizeof(struct taos_data), GFP_KERNEL);
	213	if (!taos) {
	214	err = -ENOMEM;
	215	goto exit;
	216	}
	217	taos->state = TAOS_STATE_INIT;
	218	serio_set_drvdata(serio, taos);
	219
	220	err = serio_open(serio, drv);
	221	if (err)
	222	goto exit_kfree;
	223
	224	adapter = &taos->adapter;
	225	adapter->owner = THIS_MODULE;
	226	adapter->algo = &taos_algorithm;
	227	adapter->algo_data = serio;
	228	adapter->dev.parent = &serio->dev;
	229
	230	/* Reset the TAOS evaluation module to identify it */
	231	serio_write(serio, TAOS_CMD_RESET);
	232	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
	233	msecs_to_jiffies(2000));
	234
	235	if (taos->state != TAOS_STATE_IDLE) {
	236	err = -ENODEV;
9b640f2e	237	dev_err(&serio->dev, "TAOS EVM reset failed (state=%d, "
b9cdad74 JD	238	"pos=%d)\n", taos->state, taos->pos);
	239	goto exit_close;
	240	}
	241
	242	name = taos_adapter_name(taos->buffer);
	243	if (!name) {
	244	err = -ENODEV;
	245	dev_err(&serio->dev, "TAOS EVM identification failed\n");
	246	goto exit_close;
	247	}
	248	strlcpy(adapter->name, name, sizeof(adapter->name));
	249
27693ce5 JD	250	/* Turn echo off for better performance */
	251	taos->state = TAOS_STATE_EOFF;
	252	serio_write(serio, TAOS_CMD_ECHO_OFF);
	253
	254	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
	255	msecs_to_jiffies(250));
	256	if (taos->state != TAOS_STATE_IDLE) {
	257	err = -ENODEV;
9b640f2e	258	dev_err(&serio->dev, "TAOS EVM echo off failed "
27693ce5 JD	259	"(state=%d)\n", taos->state);
	260	goto exit_close;
	261	}
	262
b9cdad74 JD	263	err = i2c_add_adapter(adapter);
	264	if (err)
	265	goto exit_close;
9b640f2e	266	dev_info(&serio->dev, "Connected to TAOS EVM\n");
b9cdad74 JD	267
	268	taos->client = taos_instantiate_device(adapter);
	269	return 0;
	270
	271	exit_close:
	272	serio_close(serio);
	273	exit_kfree:
b9cdad74 JD	274	kfree(taos);
	275	exit:
	276	return err;
	277	}
	278
	279	static void taos_disconnect(struct serio *serio)
	280	{
	281	struct taos_data *taos = serio_get_drvdata(serio);
	282
	283	if (taos->client)
	284	i2c_unregister_device(taos->client);
	285	i2c_del_adapter(&taos->adapter);
	286	serio_close(serio);
b9cdad74 JD	287	kfree(taos);
b9cdad74 JD	288
9b640f2e	289	dev_info(&serio->dev, "Disconnected from TAOS EVM\n");
b9cdad74 JD	290	}
	291
	292	static struct serio_device_id taos_serio_ids[] = {
	293	{
	294	.type = SERIO_RS232,
	295	.proto = SERIO_TAOSEVM,
	296	.id = SERIO_ANY,
	297	.extra = SERIO_ANY,
	298	},
	299	{ 0 }
	300	};
	301	MODULE_DEVICE_TABLE(serio, taos_serio_ids);
	302
	303	static struct serio_driver taos_drv = {
	304	.driver = {
	305	.name = "taos-evm",
	306	},
	307	.description = "TAOS evaluation module driver",
	308	.id_table = taos_serio_ids,
	309	.connect = taos_connect,
	310	.disconnect = taos_disconnect,
	311	.interrupt = taos_interrupt,
	312	};
	313
	314	static int __init taos_init(void)
	315	{
	316	return serio_register_driver(&taos_drv);
	317	}
	318
	319	static void __exit taos_exit(void)
	320	{
	321	serio_unregister_driver(&taos_drv);
	322	}
	323
7c81c60f	324	MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
b9cdad74 JD	325	MODULE_DESCRIPTION("TAOS evaluation module driver");
	326	MODULE_LICENSE("GPL");
	327
	328	module_init(taos_init);
	329	module_exit(taos_exit);