xref: /openbmc/linux/drivers/media/usb/gspca/stk1135.c (revision 293d5b43)
1 /*
2  * Syntek STK1135 subdriver
3  *
4  * Copyright (c) 2013 Ondrej Zary
5  *
6  * Based on Syntekdriver (stk11xx) by Nicolas VIVIEN:
7  *   http://syntekdriver.sourceforge.net
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22  */
23 
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 
26 #define MODULE_NAME "stk1135"
27 
28 #include "gspca.h"
29 #include "stk1135.h"
30 
31 MODULE_AUTHOR("Ondrej Zary");
32 MODULE_DESCRIPTION("Syntek STK1135 USB Camera Driver");
33 MODULE_LICENSE("GPL");
34 
35 
36 /* specific webcam descriptor */
37 struct sd {
38 	struct gspca_dev gspca_dev;	/* !! must be the first item */
39 
40 	u8 pkt_seq;
41 	u8 sensor_page;
42 
43 	bool flip_status;
44 	u8 flip_debounce;
45 
46 	struct v4l2_ctrl *hflip;
47 	struct v4l2_ctrl *vflip;
48 };
49 
50 static const struct v4l2_pix_format stk1135_modes[] = {
51 	/* default mode (this driver supports variable resolution) */
52 	{640, 480, V4L2_PIX_FMT_SBGGR8, V4L2_FIELD_NONE,
53 		.bytesperline = 640,
54 		.sizeimage = 640 * 480,
55 		.colorspace = V4L2_COLORSPACE_SRGB},
56 };
57 
58 /* -- read a register -- */
59 static u8 reg_r(struct gspca_dev *gspca_dev, u16 index)
60 {
61 	struct usb_device *dev = gspca_dev->dev;
62 	int ret;
63 
64 	if (gspca_dev->usb_err < 0)
65 		return 0;
66 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
67 			0x00,
68 			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
69 			0x00,
70 			index,
71 			gspca_dev->usb_buf, 1,
72 			500);
73 
74 	PDEBUG(D_USBI, "reg_r 0x%x=0x%02x", index, gspca_dev->usb_buf[0]);
75 	if (ret < 0) {
76 		pr_err("reg_r 0x%x err %d\n", index, ret);
77 		gspca_dev->usb_err = ret;
78 		return 0;
79 	}
80 
81 	return gspca_dev->usb_buf[0];
82 }
83 
84 /* -- write a register -- */
85 static void reg_w(struct gspca_dev *gspca_dev, u16 index, u8 val)
86 {
87 	int ret;
88 	struct usb_device *dev = gspca_dev->dev;
89 
90 	if (gspca_dev->usb_err < 0)
91 		return;
92 	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
93 			0x01,
94 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
95 			val,
96 			index,
97 			NULL,
98 			0,
99 			500);
100 	PDEBUG(D_USBO, "reg_w 0x%x:=0x%02x", index, val);
101 	if (ret < 0) {
102 		pr_err("reg_w 0x%x err %d\n", index, ret);
103 		gspca_dev->usb_err = ret;
104 	}
105 }
106 
107 static void reg_w_mask(struct gspca_dev *gspca_dev, u16 index, u8 val, u8 mask)
108 {
109 	val = (reg_r(gspca_dev, index) & ~mask) | (val & mask);
110 	reg_w(gspca_dev, index, val);
111 }
112 
113 /* this function is called at probe time */
114 static int sd_config(struct gspca_dev *gspca_dev,
115 			const struct usb_device_id *id)
116 {
117 	gspca_dev->cam.cam_mode = stk1135_modes;
118 	gspca_dev->cam.nmodes = ARRAY_SIZE(stk1135_modes);
119 	return 0;
120 }
121 
122 static int stk1135_serial_wait_ready(struct gspca_dev *gspca_dev)
123 {
124 	int i = 0;
125 	u8 val;
126 
127 	do {
128 		val = reg_r(gspca_dev, STK1135_REG_SICTL + 1);
129 		if (i++ > 500) { /* maximum retry count */
130 			pr_err("serial bus timeout: status=0x%02x\n", val);
131 			return -1;
132 		}
133 	/* repeat if BUSY or WRITE/READ not finished */
134 	} while ((val & 0x10) || !(val & 0x05));
135 
136 	return 0;
137 }
138 
139 static u8 sensor_read_8(struct gspca_dev *gspca_dev, u8 addr)
140 {
141 	reg_w(gspca_dev, STK1135_REG_SBUSR, addr);
142 	/* begin read */
143 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x20);
144 	/* wait until finished */
145 	if (stk1135_serial_wait_ready(gspca_dev)) {
146 		pr_err("Sensor read failed\n");
147 		return 0;
148 	}
149 
150 	return reg_r(gspca_dev, STK1135_REG_SBUSR + 1);
151 }
152 
153 static u16 sensor_read_16(struct gspca_dev *gspca_dev, u8 addr)
154 {
155 	return (sensor_read_8(gspca_dev, addr) << 8) |
156 		sensor_read_8(gspca_dev, 0xf1);
157 }
158 
159 static void sensor_write_8(struct gspca_dev *gspca_dev, u8 addr, u8 data)
160 {
161 	/* load address and data registers */
162 	reg_w(gspca_dev, STK1135_REG_SBUSW, addr);
163 	reg_w(gspca_dev, STK1135_REG_SBUSW + 1, data);
164 	/* begin write */
165 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x01);
166 	/* wait until finished */
167 	if (stk1135_serial_wait_ready(gspca_dev)) {
168 		pr_err("Sensor write failed\n");
169 		return;
170 	}
171 }
172 
173 static void sensor_write_16(struct gspca_dev *gspca_dev, u8 addr, u16 data)
174 {
175 	sensor_write_8(gspca_dev, addr, data >> 8);
176 	sensor_write_8(gspca_dev, 0xf1, data & 0xff);
177 }
178 
179 static void sensor_set_page(struct gspca_dev *gspca_dev, u8 page)
180 {
181 	struct sd *sd = (struct sd *) gspca_dev;
182 
183 	if (page != sd->sensor_page) {
184 		sensor_write_16(gspca_dev, 0xf0, page);
185 		sd->sensor_page = page;
186 	}
187 }
188 
189 static u16 sensor_read(struct gspca_dev *gspca_dev, u16 reg)
190 {
191 	sensor_set_page(gspca_dev, reg >> 8);
192 	return sensor_read_16(gspca_dev, reg & 0xff);
193 }
194 
195 static void sensor_write(struct gspca_dev *gspca_dev, u16 reg, u16 val)
196 {
197 	sensor_set_page(gspca_dev, reg >> 8);
198 	sensor_write_16(gspca_dev, reg & 0xff, val);
199 }
200 
201 static void sensor_write_mask(struct gspca_dev *gspca_dev,
202 			u16 reg, u16 val, u16 mask)
203 {
204 	val = (sensor_read(gspca_dev, reg) & ~mask) | (val & mask);
205 	sensor_write(gspca_dev, reg, val);
206 }
207 
208 struct sensor_val {
209 	u16 reg;
210 	u16 val;
211 };
212 
213 /* configure MT9M112 sensor */
214 static void stk1135_configure_mt9m112(struct gspca_dev *gspca_dev)
215 {
216 	static const struct sensor_val cfg[] = {
217 		/* restart&reset, chip enable, reserved */
218 		{ 0x00d, 0x000b }, { 0x00d, 0x0008 }, { 0x035, 0x0022 },
219 		/* mode ctl: AWB on, AE both, clip aper corr, defect corr, AE */
220 		{ 0x106, 0x700e },
221 
222 		{ 0x2dd, 0x18e0 }, /* B-R thresholds, */
223 
224 		/* AWB */
225 		{ 0x21f, 0x0180 }, /* Cb and Cr limits */
226 		{ 0x220, 0xc814 }, { 0x221, 0x8080 }, /* lum limits, RGB gain */
227 		{ 0x222, 0xa078 }, { 0x223, 0xa078 }, /* R, B limit */
228 		{ 0x224, 0x5f20 }, { 0x228, 0xea02 }, /* mtx adj lim, adv ctl */
229 		{ 0x229, 0x867a }, /* wide gates */
230 
231 		/* Color correction */
232 		/* imager gains base, delta, delta signs */
233 		{ 0x25e, 0x594c }, { 0x25f, 0x4d51 }, { 0x260, 0x0002 },
234 		/* AWB adv ctl 2, gain offs */
235 		{ 0x2ef, 0x0008 }, { 0x2f2, 0x0000 },
236 		/* base matrix signs, scale K1-5, K6-9 */
237 		{ 0x202, 0x00ee }, { 0x203, 0x3923 }, { 0x204, 0x0724 },
238 		/* base matrix coef */
239 		{ 0x209, 0x00cd }, { 0x20a, 0x0093 }, { 0x20b, 0x0004 },/*K1-3*/
240 		{ 0x20c, 0x005c }, { 0x20d, 0x00d9 }, { 0x20e, 0x0053 },/*K4-6*/
241 		{ 0x20f, 0x0008 }, { 0x210, 0x0091 }, { 0x211, 0x00cf },/*K7-9*/
242 		{ 0x215, 0x0000 }, /* delta mtx signs */
243 		/* delta matrix coef */
244 		{ 0x216, 0x0000 }, { 0x217, 0x0000 }, { 0x218, 0x0000 },/*D1-3*/
245 		{ 0x219, 0x0000 }, { 0x21a, 0x0000 }, { 0x21b, 0x0000 },/*D4-6*/
246 		{ 0x21c, 0x0000 }, { 0x21d, 0x0000 }, { 0x21e, 0x0000 },/*D7-9*/
247 		/* enable & disable manual WB to apply color corr. settings */
248 		{ 0x106, 0xf00e }, { 0x106, 0x700e },
249 
250 		/* Lens shading correction */
251 		{ 0x180, 0x0007 }, /* control */
252 		/* vertical knee 0, 2+1, 4+3 */
253 		{ 0x181, 0xde13 }, { 0x182, 0xebe2 }, { 0x183, 0x00f6 }, /* R */
254 		{ 0x184, 0xe114 }, { 0x185, 0xeadd }, { 0x186, 0xfdf6 }, /* G */
255 		{ 0x187, 0xe511 }, { 0x188, 0xede6 }, { 0x189, 0xfbf7 }, /* B */
256 		/* horizontal knee 0, 2+1, 4+3, 5 */
257 		{ 0x18a, 0xd613 }, { 0x18b, 0xedec }, /* R .. */
258 		{ 0x18c, 0xf9f2 }, { 0x18d, 0x0000 }, /* .. R */
259 		{ 0x18e, 0xd815 }, { 0x18f, 0xe9ea }, /* G .. */
260 		{ 0x190, 0xf9f1 }, { 0x191, 0x0002 }, /* .. G */
261 		{ 0x192, 0xde10 }, { 0x193, 0xefef }, /* B .. */
262 		{ 0x194, 0xfbf4 }, { 0x195, 0x0002 }, /* .. B */
263 		/* vertical knee 6+5, 8+7 */
264 		{ 0x1b6, 0x0e06 }, { 0x1b7, 0x2713 }, /* R */
265 		{ 0x1b8, 0x1106 }, { 0x1b9, 0x2713 }, /* G */
266 		{ 0x1ba, 0x0c03 }, { 0x1bb, 0x2a0f }, /* B */
267 		/* horizontal knee 7+6, 9+8, 10 */
268 		{ 0x1bc, 0x1208 }, { 0x1bd, 0x1a16 }, { 0x1be, 0x0022 }, /* R */
269 		{ 0x1bf, 0x150a }, { 0x1c0, 0x1c1a }, { 0x1c1, 0x002d }, /* G */
270 		{ 0x1c2, 0x1109 }, { 0x1c3, 0x1414 }, { 0x1c4, 0x002a }, /* B */
271 		{ 0x106, 0x740e }, /* enable lens shading correction */
272 
273 		/* Gamma correction - context A */
274 		{ 0x153, 0x0b03 }, { 0x154, 0x4722 }, { 0x155, 0xac82 },
275 		{ 0x156, 0xdac7 }, { 0x157, 0xf5e9 }, { 0x158, 0xff00 },
276 		/* Gamma correction - context B */
277 		{ 0x1dc, 0x0b03 }, { 0x1dd, 0x4722 }, { 0x1de, 0xac82 },
278 		{ 0x1df, 0xdac7 }, { 0x1e0, 0xf5e9 }, { 0x1e1, 0xff00 },
279 
280 		/* output format: RGB, invert output pixclock, output bayer */
281 		{ 0x13a, 0x4300 }, { 0x19b, 0x4300 }, /* for context A, B */
282 		{ 0x108, 0x0180 }, /* format control - enable bayer row flip */
283 
284 		{ 0x22f, 0xd100 }, { 0x29c, 0xd100 }, /* AE A, B */
285 
286 		/* default prg conf, prg ctl - by 0x2d2, prg advance - PA1 */
287 		{ 0x2d2, 0x0000 }, { 0x2cc, 0x0004 }, { 0x2cb, 0x0001 },
288 
289 		{ 0x22e, 0x0c3c }, { 0x267, 0x1010 }, /* AE tgt ctl, gain lim */
290 
291 		/* PLL */
292 		{ 0x065, 0xa000 }, /* clk ctl - enable PLL (clear bit 14) */
293 		{ 0x066, 0x2003 }, { 0x067, 0x0501 }, /* PLL M=128, N=3, P=1 */
294 		{ 0x065, 0x2000 }, /* disable PLL bypass (clear bit 15) */
295 
296 		{ 0x005, 0x01b8 }, { 0x007, 0x00d8 }, /* horiz blanking B, A */
297 
298 		/* AE line size, shutter delay limit */
299 		{ 0x239, 0x06c0 }, { 0x23b, 0x040e }, /* for context A */
300 		{ 0x23a, 0x06c0 }, { 0x23c, 0x0564 }, /* for context B */
301 		/* shutter width basis 60Hz, 50Hz */
302 		{ 0x257, 0x0208 }, { 0x258, 0x0271 }, /* for context A */
303 		{ 0x259, 0x0209 }, { 0x25a, 0x0271 }, /* for context B */
304 
305 		{ 0x25c, 0x120d }, { 0x25d, 0x1712 }, /* flicker 60Hz, 50Hz */
306 		{ 0x264, 0x5e1c }, /* reserved */
307 		/* flicker, AE gain limits, gain zone limits */
308 		{ 0x25b, 0x0003 }, { 0x236, 0x7810 }, { 0x237, 0x8304 },
309 
310 		{ 0x008, 0x0021 }, /* vert blanking A */
311 	};
312 	int i;
313 	u16 width, height;
314 
315 	for (i = 0; i < ARRAY_SIZE(cfg); i++)
316 		sensor_write(gspca_dev, cfg[i].reg, cfg[i].val);
317 
318 	/* set output size */
319 	width = gspca_dev->pixfmt.width;
320 	height = gspca_dev->pixfmt.height;
321 	if (width <= 640 && height <= 512) { /* context A (half readout speed)*/
322 		sensor_write(gspca_dev, 0x1a7, width);
323 		sensor_write(gspca_dev, 0x1aa, height);
324 		/* set read mode context A */
325 		sensor_write(gspca_dev, 0x0c8, 0x0000);
326 		/* set resize, read mode, vblank, hblank context A */
327 		sensor_write(gspca_dev, 0x2c8, 0x0000);
328 	} else { /* context B (full readout speed) */
329 		sensor_write(gspca_dev, 0x1a1, width);
330 		sensor_write(gspca_dev, 0x1a4, height);
331 		/* set read mode context B */
332 		sensor_write(gspca_dev, 0x0c8, 0x0008);
333 		/* set resize, read mode, vblank, hblank context B */
334 		sensor_write(gspca_dev, 0x2c8, 0x040b);
335 	}
336 }
337 
338 static void stk1135_configure_clock(struct gspca_dev *gspca_dev)
339 {
340 	/* configure SCLKOUT */
341 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x12);
342 	/* set 1 clock per pixel */
343 	/* and positive edge clocked pulse high when pixel counter = 0 */
344 	reg_w(gspca_dev, STK1135_REG_TCP1 + 0, 0x41);
345 	reg_w(gspca_dev, STK1135_REG_TCP1 + 1, 0x00);
346 	reg_w(gspca_dev, STK1135_REG_TCP1 + 2, 0x00);
347 	reg_w(gspca_dev, STK1135_REG_TCP1 + 3, 0x00);
348 
349 	/* enable CLKOUT for sensor */
350 	reg_w(gspca_dev, STK1135_REG_SENSO + 0, 0x10);
351 	/* disable STOP clock */
352 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x00);
353 	/* set lower 8 bits of PLL feedback divider */
354 	reg_w(gspca_dev, STK1135_REG_SENSO + 3, 0x07);
355 	/* set other PLL parameters */
356 	reg_w(gspca_dev, STK1135_REG_PLLFD, 0x06);
357 	/* enable timing generator */
358 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x80);
359 	/* enable PLL */
360 	reg_w(gspca_dev, STK1135_REG_SENSO + 2, 0x04);
361 
362 	/* set serial interface clock divider (30MHz/0x1f*16+2) = 60240 kHz) */
363 	reg_w(gspca_dev, STK1135_REG_SICTL + 2, 0x1f);
364 
365 	/* wait a while for sensor to catch up */
366 	udelay(1000);
367 }
368 
369 static void stk1135_camera_disable(struct gspca_dev *gspca_dev)
370 {
371 	/* set capture end Y position to 0 */
372 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, 0x00);
373 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, 0x00);
374 	/* disable capture */
375 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x00, 0x80);
376 
377 	/* enable sensor standby and diasble chip enable */
378 	sensor_write_mask(gspca_dev, 0x00d, 0x0004, 0x000c);
379 
380 	/* disable PLL */
381 	reg_w_mask(gspca_dev, STK1135_REG_SENSO + 2, 0x00, 0x01);
382 	/* disable timing generator */
383 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x00);
384 	/* enable STOP clock */
385 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x20);
386 	/* disable CLKOUT for sensor */
387 	reg_w(gspca_dev, STK1135_REG_SENSO, 0x00);
388 
389 	/* disable sensor (GPIO5) and enable GPIO0,3,6 (?) - sensor standby? */
390 	reg_w(gspca_dev, STK1135_REG_GCTRL, 0x49);
391 }
392 
393 /* this function is called at probe and resume time */
394 static int sd_init(struct gspca_dev *gspca_dev)
395 {
396 	u16 sensor_id;
397 	char *sensor_name;
398 	struct sd *sd = (struct sd *) gspca_dev;
399 
400 	/* set GPIO3,4,5,6 direction to output */
401 	reg_w(gspca_dev, STK1135_REG_GCTRL + 2, 0x78);
402 	/* enable sensor (GPIO5) */
403 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
404 	/* disable ROM interface */
405 	reg_w(gspca_dev, STK1135_REG_GCTRL + 3, 0x80);
406 	/* enable interrupts from GPIO8 (flip sensor) and GPIO9 (???) */
407 	reg_w(gspca_dev, STK1135_REG_ICTRL + 1, 0x00);
408 	reg_w(gspca_dev, STK1135_REG_ICTRL + 3, 0x03);
409 	/* enable remote wakeup from GPIO9 (???) */
410 	reg_w(gspca_dev, STK1135_REG_RMCTL + 1, 0x00);
411 	reg_w(gspca_dev, STK1135_REG_RMCTL + 3, 0x02);
412 
413 	/* reset serial interface */
414 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x80);
415 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x00);
416 	/* set sensor address */
417 	reg_w(gspca_dev, STK1135_REG_SICTL + 3, 0xba);
418 	/* disable alt 2-wire serial interface */
419 	reg_w(gspca_dev, STK1135_REG_ASIC + 3, 0x00);
420 
421 	stk1135_configure_clock(gspca_dev);
422 
423 	/* read sensor ID */
424 	sd->sensor_page = 0xff;
425 	sensor_id = sensor_read(gspca_dev, 0x000);
426 
427 	switch (sensor_id) {
428 	case 0x148c:
429 		sensor_name = "MT9M112";
430 		break;
431 	default:
432 		sensor_name = "unknown";
433 	}
434 	pr_info("Detected sensor type %s (0x%x)\n", sensor_name, sensor_id);
435 
436 	stk1135_camera_disable(gspca_dev);
437 
438 	return gspca_dev->usb_err;
439 }
440 
441 /* -- start the camera -- */
442 static int sd_start(struct gspca_dev *gspca_dev)
443 {
444 	struct sd *sd = (struct sd *) gspca_dev;
445 	u16 width, height;
446 
447 	/* enable sensor (GPIO5) */
448 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
449 
450 	stk1135_configure_clock(gspca_dev);
451 
452 	/* set capture start position X = 0, Y = 0 */
453 	reg_w(gspca_dev, STK1135_REG_CISPO + 0, 0x00);
454 	reg_w(gspca_dev, STK1135_REG_CISPO + 1, 0x00);
455 	reg_w(gspca_dev, STK1135_REG_CISPO + 2, 0x00);
456 	reg_w(gspca_dev, STK1135_REG_CISPO + 3, 0x00);
457 
458 	/* set capture end position */
459 	width = gspca_dev->pixfmt.width;
460 	height = gspca_dev->pixfmt.height;
461 	reg_w(gspca_dev, STK1135_REG_CIEPO + 0, width & 0xff);
462 	reg_w(gspca_dev, STK1135_REG_CIEPO + 1, width >> 8);
463 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, height & 0xff);
464 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, height >> 8);
465 
466 	/* set 8-bit mode */
467 	reg_w(gspca_dev, STK1135_REG_SCTRL, 0x20);
468 
469 	stk1135_configure_mt9m112(gspca_dev);
470 
471 	/* enable capture */
472 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x80, 0x80);
473 
474 	if (gspca_dev->usb_err >= 0)
475 		PDEBUG(D_STREAM, "camera started alt: 0x%02x",
476 				gspca_dev->alt);
477 
478 	sd->pkt_seq = 0;
479 
480 	return gspca_dev->usb_err;
481 }
482 
483 static void sd_stopN(struct gspca_dev *gspca_dev)
484 {
485 	struct usb_device *dev = gspca_dev->dev;
486 
487 	usb_set_interface(dev, gspca_dev->iface, 0);
488 
489 	stk1135_camera_disable(gspca_dev);
490 
491 	PDEBUG(D_STREAM, "camera stopped");
492 }
493 
494 static void sd_pkt_scan(struct gspca_dev *gspca_dev,
495 			u8 *data,			/* isoc packet */
496 			int len)			/* iso packet length */
497 {
498 	struct sd *sd = (struct sd *) gspca_dev;
499 	int skip = sizeof(struct stk1135_pkt_header);
500 	bool flip;
501 	enum gspca_packet_type pkt_type = INTER_PACKET;
502 	struct stk1135_pkt_header *hdr = (void *)data;
503 	u8 seq;
504 
505 	if (len < 4) {
506 		PDEBUG(D_PACK, "received short packet (less than 4 bytes)");
507 		return;
508 	}
509 
510 	/* GPIO 8 is flip sensor (1 = normal position, 0 = flipped to back) */
511 	flip = !(le16_to_cpu(hdr->gpio) & (1 << 8));
512 	/* it's a switch, needs software debounce */
513 	if (sd->flip_status != flip)
514 		sd->flip_debounce++;
515 	else
516 		sd->flip_debounce = 0;
517 
518 	/* check sequence number (not present in new frame packets) */
519 	if (!(hdr->flags & STK1135_HDR_FRAME_START)) {
520 		seq = hdr->seq & STK1135_HDR_SEQ_MASK;
521 		if (seq != sd->pkt_seq) {
522 			PDEBUG(D_PACK, "received out-of-sequence packet");
523 			/* resync sequence and discard packet */
524 			sd->pkt_seq = seq;
525 			gspca_dev->last_packet_type = DISCARD_PACKET;
526 			return;
527 		}
528 	}
529 	sd->pkt_seq++;
530 	if (sd->pkt_seq > STK1135_HDR_SEQ_MASK)
531 		sd->pkt_seq = 0;
532 
533 	if (len == sizeof(struct stk1135_pkt_header))
534 		return;
535 
536 	if (hdr->flags & STK1135_HDR_FRAME_START) { /* new frame */
537 		skip = 8;	/* the header is longer */
538 		gspca_frame_add(gspca_dev, LAST_PACKET, data, 0);
539 		pkt_type = FIRST_PACKET;
540 	}
541 	gspca_frame_add(gspca_dev, pkt_type, data + skip, len - skip);
542 }
543 
544 static void sethflip(struct gspca_dev *gspca_dev, s32 val)
545 {
546 	struct sd *sd = (struct sd *) gspca_dev;
547 
548 	if (sd->flip_status)
549 		val = !val;
550 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0002 : 0x0000 , 0x0002);
551 }
552 
553 static void setvflip(struct gspca_dev *gspca_dev, s32 val)
554 {
555 	struct sd *sd = (struct sd *) gspca_dev;
556 
557 	if (sd->flip_status)
558 		val = !val;
559 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0001 : 0x0000 , 0x0001);
560 }
561 
562 static void stk1135_dq_callback(struct gspca_dev *gspca_dev)
563 {
564 	struct sd *sd = (struct sd *) gspca_dev;
565 
566 	if (sd->flip_debounce > 100) {
567 		sd->flip_status = !sd->flip_status;
568 		sethflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->hflip));
569 		setvflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->vflip));
570 	}
571 }
572 
573 static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
574 {
575 	struct gspca_dev *gspca_dev =
576 		container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
577 
578 	gspca_dev->usb_err = 0;
579 
580 	if (!gspca_dev->streaming)
581 		return 0;
582 
583 	switch (ctrl->id) {
584 	case V4L2_CID_HFLIP:
585 		sethflip(gspca_dev, ctrl->val);
586 		break;
587 	case V4L2_CID_VFLIP:
588 		setvflip(gspca_dev, ctrl->val);
589 		break;
590 	}
591 
592 	return gspca_dev->usb_err;
593 }
594 
595 static const struct v4l2_ctrl_ops sd_ctrl_ops = {
596 	.s_ctrl = sd_s_ctrl,
597 };
598 
599 static int sd_init_controls(struct gspca_dev *gspca_dev)
600 {
601 	struct sd *sd = (struct sd *) gspca_dev;
602 	struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;
603 
604 	gspca_dev->vdev.ctrl_handler = hdl;
605 	v4l2_ctrl_handler_init(hdl, 2);
606 	sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
607 			V4L2_CID_HFLIP, 0, 1, 1, 0);
608 	sd->vflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
609 			V4L2_CID_VFLIP, 0, 1, 1, 0);
610 
611 	if (hdl->error) {
612 		pr_err("Could not initialize controls\n");
613 		return hdl->error;
614 	}
615 	return 0;
616 }
617 
618 static void stk1135_try_fmt(struct gspca_dev *gspca_dev, struct v4l2_format *fmt)
619 {
620 	fmt->fmt.pix.width = clamp(fmt->fmt.pix.width, 32U, 1280U);
621 	fmt->fmt.pix.height = clamp(fmt->fmt.pix.height, 32U, 1024U);
622 	/* round up to even numbers */
623 	fmt->fmt.pix.width += (fmt->fmt.pix.width & 1);
624 	fmt->fmt.pix.height += (fmt->fmt.pix.height & 1);
625 
626 	fmt->fmt.pix.bytesperline = fmt->fmt.pix.width;
627 	fmt->fmt.pix.sizeimage = fmt->fmt.pix.width * fmt->fmt.pix.height;
628 }
629 
630 static int stk1135_enum_framesizes(struct gspca_dev *gspca_dev,
631 			struct v4l2_frmsizeenum *fsize)
632 {
633 	if (fsize->index != 0 || fsize->pixel_format != V4L2_PIX_FMT_SBGGR8)
634 		return -EINVAL;
635 
636 	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
637 	fsize->stepwise.min_width = 32;
638 	fsize->stepwise.min_height = 32;
639 	fsize->stepwise.max_width = 1280;
640 	fsize->stepwise.max_height = 1024;
641 	fsize->stepwise.step_width = 2;
642 	fsize->stepwise.step_height = 2;
643 
644 	return 0;
645 }
646 
647 /* sub-driver description */
648 static const struct sd_desc sd_desc = {
649 	.name = MODULE_NAME,
650 	.config = sd_config,
651 	.init = sd_init,
652 	.init_controls = sd_init_controls,
653 	.start = sd_start,
654 	.stopN = sd_stopN,
655 	.pkt_scan = sd_pkt_scan,
656 	.dq_callback = stk1135_dq_callback,
657 	.try_fmt = stk1135_try_fmt,
658 	.enum_framesizes = stk1135_enum_framesizes,
659 };
660 
661 /* -- module initialisation -- */
662 static const struct usb_device_id device_table[] = {
663 	{USB_DEVICE(0x174f, 0x6a31)},	/* ASUS laptop, MT9M112 sensor */
664 	{}
665 };
666 MODULE_DEVICE_TABLE(usb, device_table);
667 
668 /* -- device connect -- */
669 static int sd_probe(struct usb_interface *intf,
670 			const struct usb_device_id *id)
671 {
672 	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
673 				THIS_MODULE);
674 }
675 
676 static struct usb_driver sd_driver = {
677 	.name = MODULE_NAME,
678 	.id_table = device_table,
679 	.probe = sd_probe,
680 	.disconnect = gspca_disconnect,
681 #ifdef CONFIG_PM
682 	.suspend = gspca_suspend,
683 	.resume = gspca_resume,
684 	.reset_resume = gspca_resume,
685 #endif
686 };
687 
688 module_usb_driver(sd_driver);
689