[linux-2.6-block.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 <khali@linux-fr.org>
 *
 * 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_SEND		2
#define TAOS_STATE_RECV		3

#define TAOS_CMD_RESET		0x12

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),
	.type	= "tsl2550",
};

/* 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.driver_name, 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_dbg(&adapter->dev, "Unsupported transaction size %d\n",
			size);
		return -EINVAL;
	}

	/* Send the transaction to the TAOS EVM */
	dev_dbg(&adapter->dev, "Command buffer: %s\n", taos->buffer);
	taos->pos = 0;
	taos->state = TAOS_STATE_SEND;
	serio_write(serio, taos->buffer[0]);
	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
					 msecs_to_jiffies(250));
	if (taos->state != TAOS_STATE_IDLE) {
		dev_err(&adapter->dev, "Transaction failed "
			"(state=%d, pos=%d)\n", taos->state, taos->pos);
		taos->addr = 0;
		return -EIO;
	}
	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 != 6) {
		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 + 2;
	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_SEND:
		if (taos->buffer[++taos->pos])
			serio_write(serio, taos->buffer[taos->pos]);
		else {
			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_dbg(&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));

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

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

 exit_close:
	serio_close(serio);
 exit_kfree:
	serio_set_drvdata(serio, NULL);
	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);
	serio_set_drvdata(serio, NULL);
	kfree(taos);

	dev_dbg(&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 <khali@linux-fr.org>");
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	*
	6	* Copyright (C) 2007 Jean Delvare <khali@linux-fr.org>
	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
	35	#define TAOS_STATE_SEND 2
	36	#define TAOS_STATE_RECV 3
	37
	38	#define TAOS_CMD_RESET 0x12
	39
	40	static DECLARE_WAIT_QUEUE_HEAD(wq);
	41
	42	struct taos_data {
	43	struct i2c_adapter adapter;
	44	struct i2c_client *client;
	45	int state;
	46	u8 addr; /* last used address */
	47	unsigned char buffer[TAOS_BUFFER_SIZE];
	48	unsigned int pos; /* position inside the buffer */
	49	};
	50
	51	/* TAOS TSL2550 EVM */
	52	static struct i2c_board_info tsl2550_info = {
	53	I2C_BOARD_INFO("tsl2550", 0x39),
	54	.type = "tsl2550",
	55	};
	56
	57	/* Instantiate i2c devices based on the adapter name */
	58	static struct i2c_client taos_instantiate_device(struct i2c_adapter adapter)
	59	{
	60	if (!strncmp(adapter->name, "TAOS TSL2550 EVM", 16)) {
	61	dev_info(&adapter->dev, "Instantiating device %s at 0x%02x\n",
	62	tsl2550_info.driver_name, tsl2550_info.addr);
	63	return i2c_new_device(adapter, &tsl2550_info);
	64	}
65
66	return NULL;
67	}
68
69	static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
70	unsigned short flags, char read_write, u8 command,
71	int size, union i2c_smbus_data *data)
72	{
73	struct serio *serio = adapter->algo_data;
74	struct taos_data *taos = serio_get_drvdata(serio);
75	char *p;
76
77	/* Encode our transaction. "@" is for the device address, "$" for the
78	SMBus command and "#" for the data. */
79	p = taos->buffer;
80
81	/* The device remembers the last used address, no need to send it
82	again if it's the same */
83	if (addr != taos->addr)
84	p += sprintf(p, "@%02X", addr);
85
86	switch (size) {
87	case I2C_SMBUS_BYTE:
88	if (read_write == I2C_SMBUS_WRITE)
89	sprintf(p, "$#%02X", command);
90	else
91	sprintf(p, "$");
92	break;
93	case I2C_SMBUS_BYTE_DATA:
94	if (read_write == I2C_SMBUS_WRITE)
95	sprintf(p, "$%02X#%02X", command, data->byte);
96	else
97	sprintf(p, "$%02X", command);
98	break;
99	default:
100	dev_dbg(&adapter->dev, "Unsupported transaction size %d\n",
101	size);
102	return -EINVAL;
103	}
104
105	/* Send the transaction to the TAOS EVM */
106	dev_dbg(&adapter->dev, "Command buffer: %s\n", taos->buffer);
107	taos->pos = 0;
108	taos->state = TAOS_STATE_SEND;
109	serio_write(serio, taos->buffer[0]);
110	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
111	msecs_to_jiffies(250));
112	if (taos->state != TAOS_STATE_IDLE) {
113	dev_err(&adapter->dev, "Transaction failed "
114	"(state=%d, pos=%d)\n", taos->state, taos->pos);
115	taos->addr = 0;
116	return -EIO;
117	}
118	taos->addr = addr;
119
120	/* Start the transaction and read the answer */
121	taos->pos = 0;
122	taos->state = TAOS_STATE_RECV;
123	serio_write(serio, read_write == I2C_SMBUS_WRITE ? '>' : '<');
124	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
125	msecs_to_jiffies(150));
126	if (taos->state != TAOS_STATE_IDLE
127	\|\| taos->pos != 6) {
128	dev_err(&adapter->dev, "Transaction timeout (pos=%d)\n",
129	taos->pos);
130	return -EIO;
131	}
132	dev_dbg(&adapter->dev, "Answer buffer: %s\n", taos->buffer);
133
134	/* Interpret the returned string */
135	p = taos->buffer + 2;
136	p[3] = '\0';
137	if (!strcmp(p, "NAK"))
138	return -ENODEV;
139
140	if (read_write == I2C_SMBUS_WRITE) {
141	if (!strcmp(p, "ACK"))
142	return 0;
143	} else {
144	if (p[0] == 'x') {
145	data->byte = simple_strtol(p + 1, NULL, 16);
146	return 0;
147	}
148	}
149
150	return -EIO;
151	}
152
153	static u32 taos_smbus_func(struct i2c_adapter *adapter)
154	{
155	return I2C_FUNC_SMBUS_BYTE \| I2C_FUNC_SMBUS_BYTE_DATA;
156	}
157
158	static const struct i2c_algorithm taos_algorithm = {
159	.smbus_xfer = taos_smbus_xfer,
160	.functionality = taos_smbus_func,
161	};
162
163	static irqreturn_t taos_interrupt(struct serio *serio, unsigned char data,
164	unsigned int flags)
165	{
166	struct taos_data *taos = serio_get_drvdata(serio);
167
168	switch (taos->state) {
169	case TAOS_STATE_INIT:
170	taos->buffer[taos->pos++] = data;
171	if (data == ':'
172	\|\| taos->pos == TAOS_BUFFER_SIZE - 1) {
173	taos->buffer[taos->pos] = '\0';
174	taos->state = TAOS_STATE_IDLE;
175	wake_up_interruptible(&wq);
176	}
177	break;
178	case TAOS_STATE_SEND:
179	if (taos->buffer[++taos->pos])
180	serio_write(serio, taos->buffer[taos->pos]);
181	else {
182	taos->state = TAOS_STATE_IDLE;
183	wake_up_interruptible(&wq);
184	}
185	break;
186	case TAOS_STATE_RECV:
187	taos->buffer[taos->pos++] = data;
188	if (data == ']') {
189	taos->buffer[taos->pos] = '\0';
190	taos->state = TAOS_STATE_IDLE;
191	wake_up_interruptible(&wq);
192	}
193	break;
194	}
195
196	return IRQ_HANDLED;
197	}
198
199	/* Extract the adapter name from the buffer received after reset.
200	The buffer is modified and a pointer inside the buffer is returned. */
201	static char taos_adapter_name(char buffer)
202	{
203	char start, end;
204
205	start = strstr(buffer, "TAOS ");
206	if (!start)
207	return NULL;
208
209	end = strchr(start, '\r');
210	if (!end)
211	return NULL;
212	*end = '\0';
213
214	return start;
215	}
216
217	static int taos_connect(struct serio serio, struct serio_driver drv)
218	{
219	struct taos_data *taos;
220	struct i2c_adapter *adapter;
221	char *name;
222	int err;
223
224	taos = kzalloc(sizeof(struct taos_data), GFP_KERNEL);
225	if (!taos) {
226	err = -ENOMEM;
227	goto exit;
228	}
229	taos->state = TAOS_STATE_INIT;
230	serio_set_drvdata(serio, taos);
231
232	err = serio_open(serio, drv);
233	if (err)
234	goto exit_kfree;
235
236	adapter = &taos->adapter;
237	adapter->owner = THIS_MODULE;
238	adapter->algo = &taos_algorithm;
239	adapter->algo_data = serio;
240	adapter->dev.parent = &serio->dev;
241
242	/* Reset the TAOS evaluation module to identify it */
243	serio_write(serio, TAOS_CMD_RESET);
244	wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE,
245	msecs_to_jiffies(2000));
246
247	if (taos->state != TAOS_STATE_IDLE) {
248	err = -ENODEV;
249	dev_dbg(&serio->dev, "TAOS EVM reset failed (state=%d, "
250	"pos=%d)\n", taos->state, taos->pos);
251	goto exit_close;
252	}
253
254	name = taos_adapter_name(taos->buffer);
255	if (!name) {
256	err = -ENODEV;
257	dev_err(&serio->dev, "TAOS EVM identification failed\n");
258	goto exit_close;
259	}
260	strlcpy(adapter->name, name, sizeof(adapter->name));
261
262	err = i2c_add_adapter(adapter);
263	if (err)
264	goto exit_close;
265	dev_dbg(&serio->dev, "Connected to TAOS EVM\n");
266
267	taos->client = taos_instantiate_device(adapter);
268	return 0;
269
270	exit_close:
271	serio_close(serio);
272	exit_kfree:
273	serio_set_drvdata(serio, NULL);
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);
287	serio_set_drvdata(serio, NULL);
288	kfree(taos);
289
290	dev_dbg(&serio->dev, "Disconnected from TAOS EVM\n");
291	}
292
293	static struct serio_device_id taos_serio_ids[] = {
294	{
295	.type = SERIO_RS232,
296	.proto = SERIO_TAOSEVM,
297	.id = SERIO_ANY,
298	.extra = SERIO_ANY,
299	},
300	{ 0 }
301	};
302	MODULE_DEVICE_TABLE(serio, taos_serio_ids);
303
304	static struct serio_driver taos_drv = {
305	.driver = {
306	.name = "taos-evm",
307	},
308	.description = "TAOS evaluation module driver",
309	.id_table = taos_serio_ids,
310	.connect = taos_connect,
311	.disconnect = taos_disconnect,
312	.interrupt = taos_interrupt,
313	};
314
315	static int __init taos_init(void)
316	{
317	return serio_register_driver(&taos_drv);
318	}
319
320	static void __exit taos_exit(void)
321	{
322	serio_unregister_driver(&taos_drv);
323	}
324
325	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
326	MODULE_DESCRIPTION("TAOS evaluation module driver");
327	MODULE_LICENSE("GPL");
328
329	module_init(taos_init);
330	module_exit(taos_exit);