[mirror_ubuntu-artful-kernel.git] / drivers / media / video / gspca / sq905.c

/*
 * SQ905 subdriver
 *
 * Copyright (C) 2008, 2009 Adam Baker and Theodore Kilgore
 *
 * 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; either version 2 of the License, or
 * any later version.
 *
 * 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
 */

/*
 * History and Acknowledgments
 *
 * The original Linux driver for SQ905 based cameras was written by
 * Marcell Lengyel and furter developed by many other contributers
 * and is available from http://sourceforge.net/projects/sqcam/
 *
 * This driver takes advantage of the reverse engineering work done for
 * that driver and for libgphoto2 but shares no code with them.
 *
 * This driver has used as a base the finepix driver and other gspca
 * based drivers and may still contain code fragments taken from those
 * drivers.
 */

#define MODULE_NAME "sq905"

#include <linux/workqueue.h>
#include "gspca.h"

MODULE_AUTHOR("Adam Baker <linux@baker-net.org.uk>, "
		"Theodore Kilgore <kilgota@auburn.edu>");
MODULE_DESCRIPTION("GSPCA/SQ905 USB Camera Driver");
MODULE_LICENSE("GPL");

/* Default timeouts, in ms */
#define SQ905_CMD_TIMEOUT 500
#define SQ905_DATA_TIMEOUT 1000

/* Maximum transfer size to use. */
#define SQ905_MAX_TRANSFER 0x8000
#define FRAME_HEADER_LEN 64

/* The known modes, or registers. These go in the "value" slot. */

/* 00 is "none" obviously */

#define SQ905_BULK_READ	0x03	/* precedes any bulk read */
#define SQ905_COMMAND	0x06	/* precedes the command codes below */
#define SQ905_PING	0x07	/* when reading an "idling" command */
#define SQ905_READ_DONE 0xc0    /* ack bulk read completed */

/* Some command codes. These go in the "index" slot. */

#define SQ905_ID      0xf0	/* asks for model string */
#define SQ905_CONFIG  0x20	/* gets photo alloc. table, not used here */
#define SQ905_DATA    0x30	/* accesses photo data, not used here */
#define SQ905_CLEAR   0xa0	/* clear everything */
#define SQ905_CAPTURE_LOW 0x60	/* Starts capture at 160x120 */
#define SQ905_CAPTURE_MED 0x61	/* Starts capture at 320x240 */
/* note that the capture command also controls the output dimensions */
/* 0x60 -> 160x120, 0x61 -> 320x240 0x62 -> 640x480 depends on camera */
/* 0x62 is not correct, at least for some cams. Should be 0x63 ? */

/* Structure to hold all of our device specific stuff */
struct sd {
	struct gspca_dev gspca_dev;	/* !! must be the first item */

	u8 cam_type;

	/*
	 * Driver stuff
	 */
	struct work_struct work_struct;
	struct workqueue_struct *work_thread;
};

/* The driver only supports 320x240 so far. */
static struct v4l2_pix_format sq905_mode[1] = {
	{ 320, 240, V4L2_PIX_FMT_SBGGR8, V4L2_FIELD_NONE,
		.bytesperline = 320,
		.sizeimage = 320 * 240,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.priv = 0}
};

struct cam_type {
	u32 ident_word;
	char *name;
	struct v4l2_pix_format *min_mode;
	u8 num_modes;
	u8 sensor_flags;
};

#define SQ905_FLIP_HORIZ (1 << 0)
#define SQ905_FLIP_VERT  (1 << 1)

/* Last entry is default if nothing else matches */
static struct cam_type cam_types[] = {
	{ 0x19010509, "PocketCam", &sq905_mode[0], 1, SQ905_FLIP_HORIZ },
	{ 0x32010509, "Magpix", &sq905_mode[0], 1, SQ905_FLIP_HORIZ },
	{ 0, "Default", &sq905_mode[0], 1, SQ905_FLIP_HORIZ | SQ905_FLIP_VERT }
};

/*
 * Send a command to the camera.
 */
static int sq905_command(struct gspca_dev *gspca_dev, u16 index)
{
	int ret;

	gspca_dev->usb_buf[0] = '\0';
	ret = usb_control_msg(gspca_dev->dev,
			      usb_sndctrlpipe(gspca_dev->dev, 0),
			      USB_REQ_SYNCH_FRAME,                /* request */
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			      SQ905_COMMAND, index, gspca_dev->usb_buf, 1,
			      SQ905_CMD_TIMEOUT);
	if (ret < 0) {
		PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)",
			__func__, ret);
		return ret;
	}

	ret = usb_control_msg(gspca_dev->dev,
			      usb_sndctrlpipe(gspca_dev->dev, 0),
			      USB_REQ_SYNCH_FRAME,                /* request */
			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			      SQ905_PING, 0, gspca_dev->usb_buf, 1,
			      SQ905_CMD_TIMEOUT);
	if (ret < 0) {
		PDEBUG(D_ERR, "%s: usb_control_msg failed 2 (%d)",
			__func__, ret);
		return ret;
	}

	return 0;
}

/*
 * Acknowledge the end of a frame - see warning on sq905_command.
 */
static int sq905_ack_frame(struct gspca_dev *gspca_dev)
{
	int ret;

	gspca_dev->usb_buf[0] = '\0';
	ret = usb_control_msg(gspca_dev->dev,
			      usb_sndctrlpipe(gspca_dev->dev, 0),
			      USB_REQ_SYNCH_FRAME,                /* request */
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			      SQ905_READ_DONE, 0, gspca_dev->usb_buf, 1,
			      SQ905_CMD_TIMEOUT);
	if (ret < 0) {
		PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)", __func__, ret);
		return ret;
	}

	return 0;
}

/*
 *  request and read a block of data - see warning on sq905_command.
 */
static int
sq905_read_data(struct gspca_dev *gspca_dev, u8 *data, int size)
{
	int ret;
	int act_len;

	gspca_dev->usb_buf[0] = '\0';
	ret = usb_control_msg(gspca_dev->dev,
			      usb_sndctrlpipe(gspca_dev->dev, 0),
			      USB_REQ_SYNCH_FRAME,                /* request */
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			      SQ905_BULK_READ, size, gspca_dev->usb_buf,
			      1, SQ905_CMD_TIMEOUT);
	if (ret < 0) {
		PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)", __func__, ret);
		return ret;
	}
	ret = usb_bulk_msg(gspca_dev->dev,
			   usb_rcvbulkpipe(gspca_dev->dev, 0x81),
			   data, size, &act_len, SQ905_DATA_TIMEOUT);

	/* successful, it returns 0, otherwise  negative */
	if (ret < 0 || act_len != size) {
		PDEBUG(D_ERR, "bulk read fail (%d) len %d/%d",
			ret, act_len, size);
		return -EIO;
	}
	return 0;
}

/* This function is called as a workqueue function and runs whenever the camera
 * is streaming data. Because it is a workqueue function it is allowed to sleep
 * so we can use synchronous USB calls. To avoid possible collisions with other
 * threads attempting to use the camera's USB interface we take the gspca
 * usb_lock when performing USB operations. In practice the only thing we need
 * to protect against is the usb_set_interface call that gspca makes during
 * stream_off as the camera doesn't provide any controls that the user could try
 * to change.
 */
static void sq905_dostream(struct work_struct *work)
{
	struct sd *dev = container_of(work, struct sd, work_struct);
	struct gspca_dev *gspca_dev = &dev->gspca_dev;
	struct gspca_frame *frame;
	int bytes_left; /* bytes remaining in current frame. */
	int data_len;   /* size to use for the next read. */
	int header_read; /* true if we have already read the frame header. */
	int discarding; /* true if we failed to get space for frame. */
	int packet_type;
	int ret;
	u8 *data;
	u8 *buffer;

	buffer = kmalloc(SQ905_MAX_TRANSFER, GFP_KERNEL | GFP_DMA);
	mutex_lock(&gspca_dev->usb_lock);
	if (!buffer) {
		PDEBUG(D_ERR, "Couldn't allocate USB buffer");
		goto quit_stream;
	}

	while (gspca_dev->present && gspca_dev->streaming) {
		/* Need a short delay to ensure streaming flag was set by
		 * gspca and to make sure gspca can grab the mutex. */
		mutex_unlock(&gspca_dev->usb_lock);
		msleep(1);

		/* request some data and then read it until we have
		 * a complete frame. */
		bytes_left = sq905_mode[0].sizeimage + FRAME_HEADER_LEN;
		header_read = 0;
		discarding = 0;

		while (bytes_left > 0) {
			data_len = bytes_left > SQ905_MAX_TRANSFER ?
				SQ905_MAX_TRANSFER : bytes_left;
			mutex_lock(&gspca_dev->usb_lock);
			if (!gspca_dev->present)
				goto quit_stream;
			ret = sq905_read_data(gspca_dev, buffer, data_len);
			if (ret < 0)
				goto quit_stream;
			mutex_unlock(&gspca_dev->usb_lock);
			PDEBUG(D_STREAM,
				"Got %d bytes out of %d for frame",
				data_len, bytes_left);
			bytes_left -= data_len;
			data = buffer;
			if (!header_read) {
				packet_type = FIRST_PACKET;
				/* The first 64 bytes of each frame are
				 * a header full of FF 00 bytes */
				data += FRAME_HEADER_LEN;
				data_len -= FRAME_HEADER_LEN;
				header_read = 1;
			} else if (bytes_left == 0) {
				packet_type = LAST_PACKET;
			} else {
				packet_type = INTER_PACKET;
			}
			frame = gspca_get_i_frame(gspca_dev);
			if (frame && !discarding)
				gspca_frame_add(gspca_dev, packet_type,
						frame, data, data_len);
			else
				discarding = 1;
		}
		/* acknowledge the frame */
		mutex_lock(&gspca_dev->usb_lock);
		if (!gspca_dev->present)
			goto quit_stream;
		ret = sq905_ack_frame(gspca_dev);
		if (ret < 0)
			goto quit_stream;
	}
quit_stream:
	/* the usb_lock is already acquired */
	if (gspca_dev->present)
		sq905_command(gspca_dev, SQ905_CLEAR);
	mutex_unlock(&gspca_dev->usb_lock);
	kfree(buffer);
}

/* This function is called at probe time just before sd_init */
static int sd_config(struct gspca_dev *gspca_dev,
		const struct usb_device_id *id)
{
	struct cam *cam = &gspca_dev->cam;
	struct sd *dev = (struct sd *) gspca_dev;

	cam->cam_mode = sq905_mode;
	cam->nmodes = 1;
	/* We don't use the buffer gspca allocates so make it small. */
	cam->bulk_size = 64;

	INIT_WORK(&dev->work_struct, sq905_dostream);

	return 0;
}

/* called on streamoff with alt==0 and on disconnect */
/* the usb_lock is held at entry - restore on exit */
static void sd_stop0(struct gspca_dev *gspca_dev)
{
	struct sd *dev = (struct sd *) gspca_dev;

	/* wait for the work queue to terminate */
	mutex_unlock(&gspca_dev->usb_lock);
	/* This waits for sq905_dostream to finish */
	destroy_workqueue(dev->work_thread);
	dev->work_thread = NULL;
	mutex_lock(&gspca_dev->usb_lock);
}

/* this function is called at probe and resume time */
static int sd_init(struct gspca_dev *gspca_dev)
{
	struct sd *dev = (struct sd *) gspca_dev;
	u32 ident;
	int ret;

	/* connect to the camera and read
	 * the model ID and process that and put it away.
	 */
	ret = sq905_command(gspca_dev, SQ905_CLEAR);
	if (ret < 0)
		return ret;
	ret = sq905_command(gspca_dev, SQ905_ID);
	if (ret < 0)
		return ret;
	ret = sq905_read_data(gspca_dev, gspca_dev->usb_buf, 4);
	if (ret < 0)
		return ret;
	/* usb_buf is allocated with kmalloc so is aligned. */
	ident = le32_to_cpup((u32 *)gspca_dev->usb_buf);
	ret = sq905_command(gspca_dev, SQ905_CLEAR);
	if (ret < 0)
		return ret;
	dev->cam_type = 0;
	while (dev->cam_type < ARRAY_SIZE(cam_types) - 1 &&
	       ident != cam_types[dev->cam_type].ident_word)
		dev->cam_type++;
	PDEBUG(D_CONF, "SQ905 camera %s, ID %08x detected",
	       cam_types[dev->cam_type].name, ident);
	return 0;
}

/* Set up for getting frames. */
static int sd_start(struct gspca_dev *gspca_dev)
{
	struct sd *dev = (struct sd *) gspca_dev;
	int ret;

	/* "Open the shutter" and set size, to start capture */
	ret = sq905_command(&dev->gspca_dev, SQ905_CAPTURE_MED);
	if (ret < 0) {
		PDEBUG(D_ERR, "Start streaming command failed");
		return ret;
	}

	/* Start the workqueue function to do the streaming */
	dev->work_thread = create_singlethread_workqueue(MODULE_NAME);
	queue_work(dev->work_thread, &dev->work_struct);

	return 0;
}

/* Table of supported USB devices */
static const __devinitdata struct usb_device_id device_table[] = {
	{USB_DEVICE(0x2770, 0x9120)},
	{}
};

MODULE_DEVICE_TABLE(usb, device_table);

/* sub-driver description */
static const struct sd_desc sd_desc = {
	.name   = MODULE_NAME,
	.config = sd_config,
	.init   = sd_init,
	.start  = sd_start,
	.stop0  = sd_stop0,
};

/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
		const struct usb_device_id *id)
{
	return gspca_dev_probe(intf, id,
			&sd_desc,
			sizeof(struct sd),
			THIS_MODULE);
}

static struct usb_driver sd_driver = {
	.name       = MODULE_NAME,
	.id_table   = device_table,
	.probe      = sd_probe,
	.disconnect = gspca_disconnect,
#ifdef CONFIG_PM
	.suspend = gspca_suspend,
	.resume  = gspca_resume,
#endif
};

/* -- module insert / remove -- */
static int __init sd_mod_init(void)
{
	int ret;

	ret = usb_register(&sd_driver);
	if (ret < 0)
		return ret;
	PDEBUG(D_PROBE, "registered");
	return 0;
}

static void __exit sd_mod_exit(void)
{
	usb_deregister(&sd_driver);
	PDEBUG(D_PROBE, "deregistered");
}

module_init(sd_mod_init);
module_exit(sd_mod_exit);
Commit	Line	Data
27d35fc3 AB	1	/*
	2	* SQ905 subdriver
	3	*
	4	* Copyright (C) 2008, 2009 Adam Baker and Theodore Kilgore
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	/*
	22	* History and Acknowledgments
	23	*
	24	* The original Linux driver for SQ905 based cameras was written by
	25	* Marcell Lengyel and furter developed by many other contributers
	26	* and is available from http://sourceforge.net/projects/sqcam/
	27	*
	28	* This driver takes advantage of the reverse engineering work done for
	29	* that driver and for libgphoto2 but shares no code with them.
	30	*
	31	* This driver has used as a base the finepix driver and other gspca
	32	* based drivers and may still contain code fragments taken from those
	33	* drivers.
	34	*/
	35
	36	#define MODULE_NAME "sq905"
	37
	38	#include <linux/workqueue.h>
	39	#include "gspca.h"
	40
	41	MODULE_AUTHOR("Adam Baker <linux@baker-net.org.uk>, "
	42	"Theodore Kilgore <kilgota@auburn.edu>");
	43	MODULE_DESCRIPTION("GSPCA/SQ905 USB Camera Driver");
	44	MODULE_LICENSE("GPL");
	45
	46	/* Default timeouts, in ms */
	47	#define SQ905_CMD_TIMEOUT 500
	48	#define SQ905_DATA_TIMEOUT 1000
	49
	50	/* Maximum transfer size to use. */
	51	#define SQ905_MAX_TRANSFER 0x8000
	52	#define FRAME_HEADER_LEN 64
	53
	54	/* The known modes, or registers. These go in the "value" slot. */
	55
	56	/* 00 is "none" obviously */
	57
	58	#define SQ905_BULK_READ 0x03 /* precedes any bulk read */
	59	#define SQ905_COMMAND 0x06 /* precedes the command codes below */
	60	#define SQ905_PING 0x07 /* when reading an "idling" command */
	61	#define SQ905_READ_DONE 0xc0 /* ack bulk read completed */
	62
	63	/* Some command codes. These go in the "index" slot. */
	64
65	#define SQ905_ID 0xf0 /* asks for model string */
66	#define SQ905_CONFIG 0x20 /* gets photo alloc. table, not used here */
67	#define SQ905_DATA 0x30 /* accesses photo data, not used here */
68	#define SQ905_CLEAR 0xa0 /* clear everything */
69	#define SQ905_CAPTURE_LOW 0x60 /* Starts capture at 160x120 */
70	#define SQ905_CAPTURE_MED 0x61 /* Starts capture at 320x240 */
71	/* note that the capture command also controls the output dimensions */
72	/* 0x60 -> 160x120, 0x61 -> 320x240 0x62 -> 640x480 depends on camera */
73	/* 0x62 is not correct, at least for some cams. Should be 0x63 ? */
74
75	/* Structure to hold all of our device specific stuff */
76	struct sd {
77	struct gspca_dev gspca_dev; /* !! must be the first item */
78
79	u8 cam_type;
80
81	/*
82	* Driver stuff
83	*/
84	struct work_struct work_struct;
85	struct workqueue_struct *work_thread;
86	};
87
88	/* The driver only supports 320x240 so far. */
89	static struct v4l2_pix_format sq905_mode[1] = {
90	{ 320, 240, V4L2_PIX_FMT_SBGGR8, V4L2_FIELD_NONE,
91	.bytesperline = 320,
92	.sizeimage = 320 * 240,
93	.colorspace = V4L2_COLORSPACE_SRGB,
94	.priv = 0}
95	};
96
97	struct cam_type {
98	u32 ident_word;
99	char *name;
100	struct v4l2_pix_format *min_mode;
101	u8 num_modes;
102	u8 sensor_flags;
103	};
104
105	#define SQ905_FLIP_HORIZ (1 << 0)
106	#define SQ905_FLIP_VERT (1 << 1)
107
108	/* Last entry is default if nothing else matches */
109	static struct cam_type cam_types[] = {
110	{ 0x19010509, "PocketCam", &sq905_mode[0], 1, SQ905_FLIP_HORIZ },
111	{ 0x32010509, "Magpix", &sq905_mode[0], 1, SQ905_FLIP_HORIZ },
112	{ 0, "Default", &sq905_mode[0], 1, SQ905_FLIP_HORIZ \| SQ905_FLIP_VERT }
113	};
114
115	/*
116	* Send a command to the camera.
117	*/
118	static int sq905_command(struct gspca_dev *gspca_dev, u16 index)
119	{
120	int ret;
121
122	gspca_dev->usb_buf[0] = '\0';
123	ret = usb_control_msg(gspca_dev->dev,
124	usb_sndctrlpipe(gspca_dev->dev, 0),
125	USB_REQ_SYNCH_FRAME, /* request */
126	USB_DIR_OUT \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE,
127	SQ905_COMMAND, index, gspca_dev->usb_buf, 1,
128	SQ905_CMD_TIMEOUT);
129	if (ret < 0) {
130	PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)",
131	__func__, ret);
132	return ret;
133	}
134
135	ret = usb_control_msg(gspca_dev->dev,
136	usb_sndctrlpipe(gspca_dev->dev, 0),
137	USB_REQ_SYNCH_FRAME, /* request */
138	USB_DIR_IN \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE,
139	SQ905_PING, 0, gspca_dev->usb_buf, 1,
140	SQ905_CMD_TIMEOUT);
141	if (ret < 0) {
142	PDEBUG(D_ERR, "%s: usb_control_msg failed 2 (%d)",
143	__func__, ret);
144	return ret;
145	}
146
147	return 0;
148	}
149
150	/*
151	* Acknowledge the end of a frame - see warning on sq905_command.
152	*/
153	static int sq905_ack_frame(struct gspca_dev *gspca_dev)
154	{
155	int ret;
156
157	gspca_dev->usb_buf[0] = '\0';
158	ret = usb_control_msg(gspca_dev->dev,
159	usb_sndctrlpipe(gspca_dev->dev, 0),
160	USB_REQ_SYNCH_FRAME, /* request */
161	USB_DIR_OUT \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE,
162	SQ905_READ_DONE, 0, gspca_dev->usb_buf, 1,
163	SQ905_CMD_TIMEOUT);
164	if (ret < 0) {
165	PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)", __func__, ret);
166	return ret;
167	}
168
169	return 0;
170	}
171
172	/*
173	* request and read a block of data - see warning on sq905_command.
174	*/
175	static int
176	sq905_read_data(struct gspca_dev gspca_dev, u8 data, int size)
177	{
178	int ret;
179	int act_len;
180
181	gspca_dev->usb_buf[0] = '\0';
182	ret = usb_control_msg(gspca_dev->dev,
183	usb_sndctrlpipe(gspca_dev->dev, 0),
184	USB_REQ_SYNCH_FRAME, /* request */
185	USB_DIR_OUT \| USB_TYPE_VENDOR \| USB_RECIP_DEVICE,
186	SQ905_BULK_READ, size, gspca_dev->usb_buf,
187	1, SQ905_CMD_TIMEOUT);
188	if (ret < 0) {
189	PDEBUG(D_ERR, "%s: usb_control_msg failed (%d)", __func__, ret);
190	return ret;
191	}
192	ret = usb_bulk_msg(gspca_dev->dev,
193	usb_rcvbulkpipe(gspca_dev->dev, 0x81),
194	data, size, &act_len, SQ905_DATA_TIMEOUT);
195
196	/* successful, it returns 0, otherwise negative */
197	if (ret < 0 \|\| act_len != size) {
198	PDEBUG(D_ERR, "bulk read fail (%d) len %d/%d",
199	ret, act_len, size);
200	return -EIO;
201	}
202	return 0;
203	}
204
205	/* This function is called as a workqueue function and runs whenever the camera
206	* is streaming data. Because it is a workqueue function it is allowed to sleep
207	* so we can use synchronous USB calls. To avoid possible collisions with other
208	* threads attempting to use the camera's USB interface we take the gspca
209	* usb_lock when performing USB operations. In practice the only thing we need
210	* to protect against is the usb_set_interface call that gspca makes during
211	* stream_off as the camera doesn't provide any controls that the user could try
212	* to change.
213	*/
214	static void sq905_dostream(struct work_struct *work)
215	{
216	struct sd *dev = container_of(work, struct sd, work_struct);
217	struct gspca_dev *gspca_dev = &dev->gspca_dev;
218	struct gspca_frame *frame;
219	int bytes_left; /* bytes remaining in current frame. */
220	int data_len; /* size to use for the next read. */
221	int header_read; /* true if we have already read the frame header. */
222	int discarding; /* true if we failed to get space for frame. */
223	int packet_type;
224	int ret;
225	u8 *data;
226	u8 *buffer;
227
228	buffer = kmalloc(SQ905_MAX_TRANSFER, GFP_KERNEL \| GFP_DMA);
229	mutex_lock(&gspca_dev->usb_lock);
230	if (!buffer) {
231	PDEBUG(D_ERR, "Couldn't allocate USB buffer");
232	goto quit_stream;
233	}
234
235	while (gspca_dev->present && gspca_dev->streaming) {
236	/* Need a short delay to ensure streaming flag was set by
237	* gspca and to make sure gspca can grab the mutex. */
238	mutex_unlock(&gspca_dev->usb_lock);
239	msleep(1);
240
241	/* request some data and then read it until we have
242	* a complete frame. */
243	bytes_left = sq905_mode[0].sizeimage + FRAME_HEADER_LEN;
244	header_read = 0;
245	discarding = 0;
246
247	while (bytes_left > 0) {
248	data_len = bytes_left > SQ905_MAX_TRANSFER ?
249	SQ905_MAX_TRANSFER : bytes_left;
250	mutex_lock(&gspca_dev->usb_lock);
251	if (!gspca_dev->present)
252	goto quit_stream;
253	ret = sq905_read_data(gspca_dev, buffer, data_len);
254	if (ret < 0)
255	goto quit_stream;
256	mutex_unlock(&gspca_dev->usb_lock);
257	PDEBUG(D_STREAM,
258	"Got %d bytes out of %d for frame",
259	data_len, bytes_left);
260	bytes_left -= data_len;
261	data = buffer;
262	if (!header_read) {
263	packet_type = FIRST_PACKET;
264	/* The first 64 bytes of each frame are
265	* a header full of FF 00 bytes */
266	data += FRAME_HEADER_LEN;
267	data_len -= FRAME_HEADER_LEN;
268	header_read = 1;
269	} else if (bytes_left == 0) {
270	packet_type = LAST_PACKET;
271	} else {
272	packet_type = INTER_PACKET;
273	}
274	frame = gspca_get_i_frame(gspca_dev);
275	if (frame && !discarding)
276	gspca_frame_add(gspca_dev, packet_type,
277	frame, data, data_len);
278	else
279	discarding = 1;
280	}
281	/* acknowledge the frame */
282	mutex_lock(&gspca_dev->usb_lock);
283	if (!gspca_dev->present)
284	goto quit_stream;
285	ret = sq905_ack_frame(gspca_dev);
286	if (ret < 0)
287	goto quit_stream;
288	}
289	quit_stream:
290	/* the usb_lock is already acquired */
291	if (gspca_dev->present)
292	sq905_command(gspca_dev, SQ905_CLEAR);
293	mutex_unlock(&gspca_dev->usb_lock);
294	kfree(buffer);
295	}
296
297	/* This function is called at probe time just before sd_init */
298	static int sd_config(struct gspca_dev *gspca_dev,
299	const struct usb_device_id *id)
300	{
301	struct cam *cam = &gspca_dev->cam;
302	struct sd dev = (struct sd ) gspca_dev;
303
304	cam->cam_mode = sq905_mode;
305	cam->nmodes = 1;
306	/* We don't use the buffer gspca allocates so make it small. */
307	cam->bulk_size = 64;
308
309	INIT_WORK(&dev->work_struct, sq905_dostream);
310
311	return 0;
312	}
313
314	/* called on streamoff with alt==0 and on disconnect */
315	/* the usb_lock is held at entry - restore on exit */
316	static void sd_stop0(struct gspca_dev *gspca_dev)
317	{
318	struct sd dev = (struct sd ) gspca_dev;
319
320	/* wait for the work queue to terminate */
321	mutex_unlock(&gspca_dev->usb_lock);
322	/* This waits for sq905_dostream to finish */
323	destroy_workqueue(dev->work_thread);
324	dev->work_thread = NULL;
325	mutex_lock(&gspca_dev->usb_lock);
326	}
327
328	/* this function is called at probe and resume time */
329	static int sd_init(struct gspca_dev *gspca_dev)
330	{
331	struct sd dev = (struct sd ) gspca_dev;
332	u32 ident;
333	int ret;
334
335	/* connect to the camera and read
336	* the model ID and process that and put it away.
337	*/
338	ret = sq905_command(gspca_dev, SQ905_CLEAR);
339	if (ret < 0)
340	return ret;
341	ret = sq905_command(gspca_dev, SQ905_ID);
342	if (ret < 0)
343	return ret;
344	ret = sq905_read_data(gspca_dev, gspca_dev->usb_buf, 4);
345	if (ret < 0)
346	return ret;
347	/* usb_buf is allocated with kmalloc so is aligned. */
348	ident = le32_to_cpup((u32 *)gspca_dev->usb_buf);
349	ret = sq905_command(gspca_dev, SQ905_CLEAR);
350	if (ret < 0)
351	return ret;
352	dev->cam_type = 0;
353	while (dev->cam_type < ARRAY_SIZE(cam_types) - 1 &&
354	ident != cam_types[dev->cam_type].ident_word)
355	dev->cam_type++;
356	PDEBUG(D_CONF, "SQ905 camera %s, ID %08x detected",
357	cam_types[dev->cam_type].name, ident);
358	return 0;
359	}
360
361	/* Set up for getting frames. */
362	static int sd_start(struct gspca_dev *gspca_dev)
363	{
364	struct sd dev = (struct sd ) gspca_dev;
365	int ret;
366
367	/* "Open the shutter" and set size, to start capture */
368	ret = sq905_command(&dev->gspca_dev, SQ905_CAPTURE_MED);
369	if (ret < 0) {
370	PDEBUG(D_ERR, "Start streaming command failed");
371	return ret;
372	}
373
374	/* Start the workqueue function to do the streaming */
375	dev->work_thread = create_singlethread_workqueue(MODULE_NAME);
376	queue_work(dev->work_thread, &dev->work_struct);
377
378	return 0;
379	}
380
381	/* Table of supported USB devices */
382	static const __devinitdata struct usb_device_id device_table[] = {
383	{USB_DEVICE(0x2770, 0x9120)},
384	{}
385	};
386
387	MODULE_DEVICE_TABLE(usb, device_table);
388
389	/* sub-driver description */
390	static const struct sd_desc sd_desc = {
391	.name = MODULE_NAME,
392	.config = sd_config,
393	.init = sd_init,
394	.start = sd_start,
395	.stop0 = sd_stop0,
396	};
397
398	/* -- device connect -- */
399	static int sd_probe(struct usb_interface *intf,
400	const struct usb_device_id *id)
401	{
402	return gspca_dev_probe(intf, id,
403	&sd_desc,
404	sizeof(struct sd),
405	THIS_MODULE);
406	}
407
408	static struct usb_driver sd_driver = {
409	.name = MODULE_NAME,
410	.id_table = device_table,
411	.probe = sd_probe,
412	.disconnect = gspca_disconnect,
413	#ifdef CONFIG_PM
414	.suspend = gspca_suspend,
415	.resume = gspca_resume,
416	#endif
417	};
418
419	/* -- module insert / remove -- */
420	static int __init sd_mod_init(void)
421	{
422	int ret;
423
424	ret = usb_register(&sd_driver);
425	if (ret < 0)
426	return ret;
427	PDEBUG(D_PROBE, "registered");
428	return 0;
429	}
430
431	static void __exit sd_mod_exit(void)
432	{
433	usb_deregister(&sd_driver);
434	PDEBUG(D_PROBE, "deregistered");
435	}
436
437	module_init(sd_mod_init);
438	module_exit(sd_mod_exit);