xref: /openbmc/linux/drivers/media/usb/gspca/stk1135.c (revision a99237af)
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 
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #define MODULE_NAME "stk1135"
23 
24 #include "gspca.h"
25 #include "stk1135.h"
26 
27 MODULE_AUTHOR("Ondrej Zary");
28 MODULE_DESCRIPTION("Syntek STK1135 USB Camera Driver");
29 MODULE_LICENSE("GPL");
30 
31 
32 /* specific webcam descriptor */
33 struct sd {
34 	struct gspca_dev gspca_dev;	/* !! must be the first item */
35 
36 	u8 pkt_seq;
37 	u8 sensor_page;
38 
39 	bool flip_status;
40 	u8 flip_debounce;
41 
42 	struct v4l2_ctrl *hflip;
43 	struct v4l2_ctrl *vflip;
44 };
45 
46 static const struct v4l2_pix_format stk1135_modes[] = {
47 	/* default mode (this driver supports variable resolution) */
48 	{640, 480, V4L2_PIX_FMT_SBGGR8, V4L2_FIELD_NONE,
49 		.bytesperline = 640,
50 		.sizeimage = 640 * 480,
51 		.colorspace = V4L2_COLORSPACE_SRGB},
52 };
53 
54 /* -- read a register -- */
55 static u8 reg_r(struct gspca_dev *gspca_dev, u16 index)
56 {
57 	struct usb_device *dev = gspca_dev->dev;
58 	int ret;
59 
60 	if (gspca_dev->usb_err < 0)
61 		return 0;
62 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
63 			0x00,
64 			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
65 			0x00,
66 			index,
67 			gspca_dev->usb_buf, 1,
68 			500);
69 
70 	gspca_dbg(gspca_dev, D_USBI, "reg_r 0x%x=0x%02x\n",
71 		  index, gspca_dev->usb_buf[0]);
72 	if (ret < 0) {
73 		pr_err("reg_r 0x%x err %d\n", index, ret);
74 		gspca_dev->usb_err = ret;
75 		return 0;
76 	}
77 
78 	return gspca_dev->usb_buf[0];
79 }
80 
81 /* -- write a register -- */
82 static void reg_w(struct gspca_dev *gspca_dev, u16 index, u8 val)
83 {
84 	int ret;
85 	struct usb_device *dev = gspca_dev->dev;
86 
87 	if (gspca_dev->usb_err < 0)
88 		return;
89 	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
90 			0x01,
91 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
92 			val,
93 			index,
94 			NULL,
95 			0,
96 			500);
97 	gspca_dbg(gspca_dev, D_USBO, "reg_w 0x%x:=0x%02x\n", index, val);
98 	if (ret < 0) {
99 		pr_err("reg_w 0x%x err %d\n", index, ret);
100 		gspca_dev->usb_err = ret;
101 	}
102 }
103 
104 static void reg_w_mask(struct gspca_dev *gspca_dev, u16 index, u8 val, u8 mask)
105 {
106 	val = (reg_r(gspca_dev, index) & ~mask) | (val & mask);
107 	reg_w(gspca_dev, index, val);
108 }
109 
110 /* this function is called at probe time */
111 static int sd_config(struct gspca_dev *gspca_dev,
112 			const struct usb_device_id *id)
113 {
114 	gspca_dev->cam.cam_mode = stk1135_modes;
115 	gspca_dev->cam.nmodes = ARRAY_SIZE(stk1135_modes);
116 	return 0;
117 }
118 
119 static int stk1135_serial_wait_ready(struct gspca_dev *gspca_dev)
120 {
121 	int i = 0;
122 	u8 val;
123 
124 	do {
125 		val = reg_r(gspca_dev, STK1135_REG_SICTL + 1);
126 		if (i++ > 500) { /* maximum retry count */
127 			pr_err("serial bus timeout: status=0x%02x\n", val);
128 			return -1;
129 		}
130 	/* repeat if BUSY or WRITE/READ not finished */
131 	} while ((val & 0x10) || !(val & 0x05));
132 
133 	return 0;
134 }
135 
136 static u8 sensor_read_8(struct gspca_dev *gspca_dev, u8 addr)
137 {
138 	reg_w(gspca_dev, STK1135_REG_SBUSR, addr);
139 	/* begin read */
140 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x20);
141 	/* wait until finished */
142 	if (stk1135_serial_wait_ready(gspca_dev)) {
143 		pr_err("Sensor read failed\n");
144 		return 0;
145 	}
146 
147 	return reg_r(gspca_dev, STK1135_REG_SBUSR + 1);
148 }
149 
150 static u16 sensor_read_16(struct gspca_dev *gspca_dev, u8 addr)
151 {
152 	return (sensor_read_8(gspca_dev, addr) << 8) |
153 		sensor_read_8(gspca_dev, 0xf1);
154 }
155 
156 static void sensor_write_8(struct gspca_dev *gspca_dev, u8 addr, u8 data)
157 {
158 	/* load address and data registers */
159 	reg_w(gspca_dev, STK1135_REG_SBUSW, addr);
160 	reg_w(gspca_dev, STK1135_REG_SBUSW + 1, data);
161 	/* begin write */
162 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x01);
163 	/* wait until finished */
164 	if (stk1135_serial_wait_ready(gspca_dev)) {
165 		pr_err("Sensor write failed\n");
166 		return;
167 	}
168 }
169 
170 static void sensor_write_16(struct gspca_dev *gspca_dev, u8 addr, u16 data)
171 {
172 	sensor_write_8(gspca_dev, addr, data >> 8);
173 	sensor_write_8(gspca_dev, 0xf1, data & 0xff);
174 }
175 
176 static void sensor_set_page(struct gspca_dev *gspca_dev, u8 page)
177 {
178 	struct sd *sd = (struct sd *) gspca_dev;
179 
180 	if (page != sd->sensor_page) {
181 		sensor_write_16(gspca_dev, 0xf0, page);
182 		sd->sensor_page = page;
183 	}
184 }
185 
186 static u16 sensor_read(struct gspca_dev *gspca_dev, u16 reg)
187 {
188 	sensor_set_page(gspca_dev, reg >> 8);
189 	return sensor_read_16(gspca_dev, reg & 0xff);
190 }
191 
192 static void sensor_write(struct gspca_dev *gspca_dev, u16 reg, u16 val)
193 {
194 	sensor_set_page(gspca_dev, reg >> 8);
195 	sensor_write_16(gspca_dev, reg & 0xff, val);
196 }
197 
198 static void sensor_write_mask(struct gspca_dev *gspca_dev,
199 			u16 reg, u16 val, u16 mask)
200 {
201 	val = (sensor_read(gspca_dev, reg) & ~mask) | (val & mask);
202 	sensor_write(gspca_dev, reg, val);
203 }
204 
205 struct sensor_val {
206 	u16 reg;
207 	u16 val;
208 };
209 
210 /* configure MT9M112 sensor */
211 static void stk1135_configure_mt9m112(struct gspca_dev *gspca_dev)
212 {
213 	static const struct sensor_val cfg[] = {
214 		/* restart&reset, chip enable, reserved */
215 		{ 0x00d, 0x000b }, { 0x00d, 0x0008 }, { 0x035, 0x0022 },
216 		/* mode ctl: AWB on, AE both, clip aper corr, defect corr, AE */
217 		{ 0x106, 0x700e },
218 
219 		{ 0x2dd, 0x18e0 }, /* B-R thresholds, */
220 
221 		/* AWB */
222 		{ 0x21f, 0x0180 }, /* Cb and Cr limits */
223 		{ 0x220, 0xc814 }, { 0x221, 0x8080 }, /* lum limits, RGB gain */
224 		{ 0x222, 0xa078 }, { 0x223, 0xa078 }, /* R, B limit */
225 		{ 0x224, 0x5f20 }, { 0x228, 0xea02 }, /* mtx adj lim, adv ctl */
226 		{ 0x229, 0x867a }, /* wide gates */
227 
228 		/* Color correction */
229 		/* imager gains base, delta, delta signs */
230 		{ 0x25e, 0x594c }, { 0x25f, 0x4d51 }, { 0x260, 0x0002 },
231 		/* AWB adv ctl 2, gain offs */
232 		{ 0x2ef, 0x0008 }, { 0x2f2, 0x0000 },
233 		/* base matrix signs, scale K1-5, K6-9 */
234 		{ 0x202, 0x00ee }, { 0x203, 0x3923 }, { 0x204, 0x0724 },
235 		/* base matrix coef */
236 		{ 0x209, 0x00cd }, { 0x20a, 0x0093 }, { 0x20b, 0x0004 },/*K1-3*/
237 		{ 0x20c, 0x005c }, { 0x20d, 0x00d9 }, { 0x20e, 0x0053 },/*K4-6*/
238 		{ 0x20f, 0x0008 }, { 0x210, 0x0091 }, { 0x211, 0x00cf },/*K7-9*/
239 		{ 0x215, 0x0000 }, /* delta mtx signs */
240 		/* delta matrix coef */
241 		{ 0x216, 0x0000 }, { 0x217, 0x0000 }, { 0x218, 0x0000 },/*D1-3*/
242 		{ 0x219, 0x0000 }, { 0x21a, 0x0000 }, { 0x21b, 0x0000 },/*D4-6*/
243 		{ 0x21c, 0x0000 }, { 0x21d, 0x0000 }, { 0x21e, 0x0000 },/*D7-9*/
244 		/* enable & disable manual WB to apply color corr. settings */
245 		{ 0x106, 0xf00e }, { 0x106, 0x700e },
246 
247 		/* Lens shading correction */
248 		{ 0x180, 0x0007 }, /* control */
249 		/* vertical knee 0, 2+1, 4+3 */
250 		{ 0x181, 0xde13 }, { 0x182, 0xebe2 }, { 0x183, 0x00f6 }, /* R */
251 		{ 0x184, 0xe114 }, { 0x185, 0xeadd }, { 0x186, 0xfdf6 }, /* G */
252 		{ 0x187, 0xe511 }, { 0x188, 0xede6 }, { 0x189, 0xfbf7 }, /* B */
253 		/* horizontal knee 0, 2+1, 4+3, 5 */
254 		{ 0x18a, 0xd613 }, { 0x18b, 0xedec }, /* R .. */
255 		{ 0x18c, 0xf9f2 }, { 0x18d, 0x0000 }, /* .. R */
256 		{ 0x18e, 0xd815 }, { 0x18f, 0xe9ea }, /* G .. */
257 		{ 0x190, 0xf9f1 }, { 0x191, 0x0002 }, /* .. G */
258 		{ 0x192, 0xde10 }, { 0x193, 0xefef }, /* B .. */
259 		{ 0x194, 0xfbf4 }, { 0x195, 0x0002 }, /* .. B */
260 		/* vertical knee 6+5, 8+7 */
261 		{ 0x1b6, 0x0e06 }, { 0x1b7, 0x2713 }, /* R */
262 		{ 0x1b8, 0x1106 }, { 0x1b9, 0x2713 }, /* G */
263 		{ 0x1ba, 0x0c03 }, { 0x1bb, 0x2a0f }, /* B */
264 		/* horizontal knee 7+6, 9+8, 10 */
265 		{ 0x1bc, 0x1208 }, { 0x1bd, 0x1a16 }, { 0x1be, 0x0022 }, /* R */
266 		{ 0x1bf, 0x150a }, { 0x1c0, 0x1c1a }, { 0x1c1, 0x002d }, /* G */
267 		{ 0x1c2, 0x1109 }, { 0x1c3, 0x1414 }, { 0x1c4, 0x002a }, /* B */
268 		{ 0x106, 0x740e }, /* enable lens shading correction */
269 
270 		/* Gamma correction - context A */
271 		{ 0x153, 0x0b03 }, { 0x154, 0x4722 }, { 0x155, 0xac82 },
272 		{ 0x156, 0xdac7 }, { 0x157, 0xf5e9 }, { 0x158, 0xff00 },
273 		/* Gamma correction - context B */
274 		{ 0x1dc, 0x0b03 }, { 0x1dd, 0x4722 }, { 0x1de, 0xac82 },
275 		{ 0x1df, 0xdac7 }, { 0x1e0, 0xf5e9 }, { 0x1e1, 0xff00 },
276 
277 		/* output format: RGB, invert output pixclock, output bayer */
278 		{ 0x13a, 0x4300 }, { 0x19b, 0x4300 }, /* for context A, B */
279 		{ 0x108, 0x0180 }, /* format control - enable bayer row flip */
280 
281 		{ 0x22f, 0xd100 }, { 0x29c, 0xd100 }, /* AE A, B */
282 
283 		/* default prg conf, prg ctl - by 0x2d2, prg advance - PA1 */
284 		{ 0x2d2, 0x0000 }, { 0x2cc, 0x0004 }, { 0x2cb, 0x0001 },
285 
286 		{ 0x22e, 0x0c3c }, { 0x267, 0x1010 }, /* AE tgt ctl, gain lim */
287 
288 		/* PLL */
289 		{ 0x065, 0xa000 }, /* clk ctl - enable PLL (clear bit 14) */
290 		{ 0x066, 0x2003 }, { 0x067, 0x0501 }, /* PLL M=128, N=3, P=1 */
291 		{ 0x065, 0x2000 }, /* disable PLL bypass (clear bit 15) */
292 
293 		{ 0x005, 0x01b8 }, { 0x007, 0x00d8 }, /* horiz blanking B, A */
294 
295 		/* AE line size, shutter delay limit */
296 		{ 0x239, 0x06c0 }, { 0x23b, 0x040e }, /* for context A */
297 		{ 0x23a, 0x06c0 }, { 0x23c, 0x0564 }, /* for context B */
298 		/* shutter width basis 60Hz, 50Hz */
299 		{ 0x257, 0x0208 }, { 0x258, 0x0271 }, /* for context A */
300 		{ 0x259, 0x0209 }, { 0x25a, 0x0271 }, /* for context B */
301 
302 		{ 0x25c, 0x120d }, { 0x25d, 0x1712 }, /* flicker 60Hz, 50Hz */
303 		{ 0x264, 0x5e1c }, /* reserved */
304 		/* flicker, AE gain limits, gain zone limits */
305 		{ 0x25b, 0x0003 }, { 0x236, 0x7810 }, { 0x237, 0x8304 },
306 
307 		{ 0x008, 0x0021 }, /* vert blanking A */
308 	};
309 	int i;
310 	u16 width, height;
311 
312 	for (i = 0; i < ARRAY_SIZE(cfg); i++)
313 		sensor_write(gspca_dev, cfg[i].reg, cfg[i].val);
314 
315 	/* set output size */
316 	width = gspca_dev->pixfmt.width;
317 	height = gspca_dev->pixfmt.height;
318 	if (width <= 640 && height <= 512) { /* context A (half readout speed)*/
319 		sensor_write(gspca_dev, 0x1a7, width);
320 		sensor_write(gspca_dev, 0x1aa, height);
321 		/* set read mode context A */
322 		sensor_write(gspca_dev, 0x0c8, 0x0000);
323 		/* set resize, read mode, vblank, hblank context A */
324 		sensor_write(gspca_dev, 0x2c8, 0x0000);
325 	} else { /* context B (full readout speed) */
326 		sensor_write(gspca_dev, 0x1a1, width);
327 		sensor_write(gspca_dev, 0x1a4, height);
328 		/* set read mode context B */
329 		sensor_write(gspca_dev, 0x0c8, 0x0008);
330 		/* set resize, read mode, vblank, hblank context B */
331 		sensor_write(gspca_dev, 0x2c8, 0x040b);
332 	}
333 }
334 
335 static void stk1135_configure_clock(struct gspca_dev *gspca_dev)
336 {
337 	/* configure SCLKOUT */
338 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x12);
339 	/* set 1 clock per pixel */
340 	/* and positive edge clocked pulse high when pixel counter = 0 */
341 	reg_w(gspca_dev, STK1135_REG_TCP1 + 0, 0x41);
342 	reg_w(gspca_dev, STK1135_REG_TCP1 + 1, 0x00);
343 	reg_w(gspca_dev, STK1135_REG_TCP1 + 2, 0x00);
344 	reg_w(gspca_dev, STK1135_REG_TCP1 + 3, 0x00);
345 
346 	/* enable CLKOUT for sensor */
347 	reg_w(gspca_dev, STK1135_REG_SENSO + 0, 0x10);
348 	/* disable STOP clock */
349 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x00);
350 	/* set lower 8 bits of PLL feedback divider */
351 	reg_w(gspca_dev, STK1135_REG_SENSO + 3, 0x07);
352 	/* set other PLL parameters */
353 	reg_w(gspca_dev, STK1135_REG_PLLFD, 0x06);
354 	/* enable timing generator */
355 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x80);
356 	/* enable PLL */
357 	reg_w(gspca_dev, STK1135_REG_SENSO + 2, 0x04);
358 
359 	/* set serial interface clock divider (30MHz/0x1f*16+2) = 60240 kHz) */
360 	reg_w(gspca_dev, STK1135_REG_SICTL + 2, 0x1f);
361 
362 	/* wait a while for sensor to catch up */
363 	udelay(1000);
364 }
365 
366 static void stk1135_camera_disable(struct gspca_dev *gspca_dev)
367 {
368 	/* set capture end Y position to 0 */
369 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, 0x00);
370 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, 0x00);
371 	/* disable capture */
372 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x00, 0x80);
373 
374 	/* enable sensor standby and diasble chip enable */
375 	sensor_write_mask(gspca_dev, 0x00d, 0x0004, 0x000c);
376 
377 	/* disable PLL */
378 	reg_w_mask(gspca_dev, STK1135_REG_SENSO + 2, 0x00, 0x01);
379 	/* disable timing generator */
380 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x00);
381 	/* enable STOP clock */
382 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x20);
383 	/* disable CLKOUT for sensor */
384 	reg_w(gspca_dev, STK1135_REG_SENSO, 0x00);
385 
386 	/* disable sensor (GPIO5) and enable GPIO0,3,6 (?) - sensor standby? */
387 	reg_w(gspca_dev, STK1135_REG_GCTRL, 0x49);
388 }
389 
390 /* this function is called at probe and resume time */
391 static int sd_init(struct gspca_dev *gspca_dev)
392 {
393 	u16 sensor_id;
394 	char *sensor_name;
395 	struct sd *sd = (struct sd *) gspca_dev;
396 
397 	/* set GPIO3,4,5,6 direction to output */
398 	reg_w(gspca_dev, STK1135_REG_GCTRL + 2, 0x78);
399 	/* enable sensor (GPIO5) */
400 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
401 	/* disable ROM interface */
402 	reg_w(gspca_dev, STK1135_REG_GCTRL + 3, 0x80);
403 	/* enable interrupts from GPIO8 (flip sensor) and GPIO9 (???) */
404 	reg_w(gspca_dev, STK1135_REG_ICTRL + 1, 0x00);
405 	reg_w(gspca_dev, STK1135_REG_ICTRL + 3, 0x03);
406 	/* enable remote wakeup from GPIO9 (???) */
407 	reg_w(gspca_dev, STK1135_REG_RMCTL + 1, 0x00);
408 	reg_w(gspca_dev, STK1135_REG_RMCTL + 3, 0x02);
409 
410 	/* reset serial interface */
411 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x80);
412 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x00);
413 	/* set sensor address */
414 	reg_w(gspca_dev, STK1135_REG_SICTL + 3, 0xba);
415 	/* disable alt 2-wire serial interface */
416 	reg_w(gspca_dev, STK1135_REG_ASIC + 3, 0x00);
417 
418 	stk1135_configure_clock(gspca_dev);
419 
420 	/* read sensor ID */
421 	sd->sensor_page = 0xff;
422 	sensor_id = sensor_read(gspca_dev, 0x000);
423 
424 	switch (sensor_id) {
425 	case 0x148c:
426 		sensor_name = "MT9M112";
427 		break;
428 	default:
429 		sensor_name = "unknown";
430 	}
431 	pr_info("Detected sensor type %s (0x%x)\n", sensor_name, sensor_id);
432 
433 	stk1135_camera_disable(gspca_dev);
434 
435 	return gspca_dev->usb_err;
436 }
437 
438 /* -- start the camera -- */
439 static int sd_start(struct gspca_dev *gspca_dev)
440 {
441 	struct sd *sd = (struct sd *) gspca_dev;
442 	u16 width, height;
443 
444 	/* enable sensor (GPIO5) */
445 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
446 
447 	stk1135_configure_clock(gspca_dev);
448 
449 	/* set capture start position X = 0, Y = 0 */
450 	reg_w(gspca_dev, STK1135_REG_CISPO + 0, 0x00);
451 	reg_w(gspca_dev, STK1135_REG_CISPO + 1, 0x00);
452 	reg_w(gspca_dev, STK1135_REG_CISPO + 2, 0x00);
453 	reg_w(gspca_dev, STK1135_REG_CISPO + 3, 0x00);
454 
455 	/* set capture end position */
456 	width = gspca_dev->pixfmt.width;
457 	height = gspca_dev->pixfmt.height;
458 	reg_w(gspca_dev, STK1135_REG_CIEPO + 0, width & 0xff);
459 	reg_w(gspca_dev, STK1135_REG_CIEPO + 1, width >> 8);
460 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, height & 0xff);
461 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, height >> 8);
462 
463 	/* set 8-bit mode */
464 	reg_w(gspca_dev, STK1135_REG_SCTRL, 0x20);
465 
466 	stk1135_configure_mt9m112(gspca_dev);
467 
468 	/* enable capture */
469 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x80, 0x80);
470 
471 	if (gspca_dev->usb_err >= 0)
472 		gspca_dbg(gspca_dev, D_STREAM, "camera started alt: 0x%02x\n",
473 			  gspca_dev->alt);
474 
475 	sd->pkt_seq = 0;
476 
477 	return gspca_dev->usb_err;
478 }
479 
480 static void sd_stopN(struct gspca_dev *gspca_dev)
481 {
482 	struct usb_device *dev = gspca_dev->dev;
483 
484 	usb_set_interface(dev, gspca_dev->iface, 0);
485 
486 	stk1135_camera_disable(gspca_dev);
487 
488 	gspca_dbg(gspca_dev, D_STREAM, "camera stopped\n");
489 }
490 
491 static void sd_pkt_scan(struct gspca_dev *gspca_dev,
492 			u8 *data,			/* isoc packet */
493 			int len)			/* iso packet length */
494 {
495 	struct sd *sd = (struct sd *) gspca_dev;
496 	int skip = sizeof(struct stk1135_pkt_header);
497 	bool flip;
498 	enum gspca_packet_type pkt_type = INTER_PACKET;
499 	struct stk1135_pkt_header *hdr = (void *)data;
500 	u8 seq;
501 
502 	if (len < 4) {
503 		gspca_dbg(gspca_dev, D_PACK, "received short packet (less than 4 bytes)\n");
504 		return;
505 	}
506 
507 	/* GPIO 8 is flip sensor (1 = normal position, 0 = flipped to back) */
508 	flip = !(le16_to_cpu(hdr->gpio) & (1 << 8));
509 	/* it's a switch, needs software debounce */
510 	if (sd->flip_status != flip)
511 		sd->flip_debounce++;
512 	else
513 		sd->flip_debounce = 0;
514 
515 	/* check sequence number (not present in new frame packets) */
516 	if (!(hdr->flags & STK1135_HDR_FRAME_START)) {
517 		seq = hdr->seq & STK1135_HDR_SEQ_MASK;
518 		if (seq != sd->pkt_seq) {
519 			gspca_dbg(gspca_dev, D_PACK, "received out-of-sequence packet\n");
520 			/* resync sequence and discard packet */
521 			sd->pkt_seq = seq;
522 			gspca_dev->last_packet_type = DISCARD_PACKET;
523 			return;
524 		}
525 	}
526 	sd->pkt_seq++;
527 	if (sd->pkt_seq > STK1135_HDR_SEQ_MASK)
528 		sd->pkt_seq = 0;
529 
530 	if (len == sizeof(struct stk1135_pkt_header))
531 		return;
532 
533 	if (hdr->flags & STK1135_HDR_FRAME_START) { /* new frame */
534 		skip = 8;	/* the header is longer */
535 		gspca_frame_add(gspca_dev, LAST_PACKET, data, 0);
536 		pkt_type = FIRST_PACKET;
537 	}
538 	gspca_frame_add(gspca_dev, pkt_type, data + skip, len - skip);
539 }
540 
541 static void sethflip(struct gspca_dev *gspca_dev, s32 val)
542 {
543 	struct sd *sd = (struct sd *) gspca_dev;
544 
545 	if (sd->flip_status)
546 		val = !val;
547 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0002 : 0x0000 , 0x0002);
548 }
549 
550 static void setvflip(struct gspca_dev *gspca_dev, s32 val)
551 {
552 	struct sd *sd = (struct sd *) gspca_dev;
553 
554 	if (sd->flip_status)
555 		val = !val;
556 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0001 : 0x0000 , 0x0001);
557 }
558 
559 static void stk1135_dq_callback(struct gspca_dev *gspca_dev)
560 {
561 	struct sd *sd = (struct sd *) gspca_dev;
562 
563 	if (sd->flip_debounce > 100) {
564 		sd->flip_status = !sd->flip_status;
565 		sethflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->hflip));
566 		setvflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->vflip));
567 	}
568 }
569 
570 static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
571 {
572 	struct gspca_dev *gspca_dev =
573 		container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
574 
575 	gspca_dev->usb_err = 0;
576 
577 	if (!gspca_dev->streaming)
578 		return 0;
579 
580 	switch (ctrl->id) {
581 	case V4L2_CID_HFLIP:
582 		sethflip(gspca_dev, ctrl->val);
583 		break;
584 	case V4L2_CID_VFLIP:
585 		setvflip(gspca_dev, ctrl->val);
586 		break;
587 	}
588 
589 	return gspca_dev->usb_err;
590 }
591 
592 static const struct v4l2_ctrl_ops sd_ctrl_ops = {
593 	.s_ctrl = sd_s_ctrl,
594 };
595 
596 static int sd_init_controls(struct gspca_dev *gspca_dev)
597 {
598 	struct sd *sd = (struct sd *) gspca_dev;
599 	struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;
600 
601 	gspca_dev->vdev.ctrl_handler = hdl;
602 	v4l2_ctrl_handler_init(hdl, 2);
603 	sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
604 			V4L2_CID_HFLIP, 0, 1, 1, 0);
605 	sd->vflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
606 			V4L2_CID_VFLIP, 0, 1, 1, 0);
607 
608 	if (hdl->error) {
609 		pr_err("Could not initialize controls\n");
610 		return hdl->error;
611 	}
612 	return 0;
613 }
614 
615 static void stk1135_try_fmt(struct gspca_dev *gspca_dev, struct v4l2_format *fmt)
616 {
617 	fmt->fmt.pix.width = clamp(fmt->fmt.pix.width, 32U, 1280U);
618 	fmt->fmt.pix.height = clamp(fmt->fmt.pix.height, 32U, 1024U);
619 	/* round up to even numbers */
620 	fmt->fmt.pix.width += (fmt->fmt.pix.width & 1);
621 	fmt->fmt.pix.height += (fmt->fmt.pix.height & 1);
622 
623 	fmt->fmt.pix.bytesperline = fmt->fmt.pix.width;
624 	fmt->fmt.pix.sizeimage = fmt->fmt.pix.width * fmt->fmt.pix.height;
625 }
626 
627 static int stk1135_enum_framesizes(struct gspca_dev *gspca_dev,
628 			struct v4l2_frmsizeenum *fsize)
629 {
630 	if (fsize->index != 0 || fsize->pixel_format != V4L2_PIX_FMT_SBGGR8)
631 		return -EINVAL;
632 
633 	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
634 	fsize->stepwise.min_width = 32;
635 	fsize->stepwise.min_height = 32;
636 	fsize->stepwise.max_width = 1280;
637 	fsize->stepwise.max_height = 1024;
638 	fsize->stepwise.step_width = 2;
639 	fsize->stepwise.step_height = 2;
640 
641 	return 0;
642 }
643 
644 /* sub-driver description */
645 static const struct sd_desc sd_desc = {
646 	.name = MODULE_NAME,
647 	.config = sd_config,
648 	.init = sd_init,
649 	.init_controls = sd_init_controls,
650 	.start = sd_start,
651 	.stopN = sd_stopN,
652 	.pkt_scan = sd_pkt_scan,
653 	.dq_callback = stk1135_dq_callback,
654 	.try_fmt = stk1135_try_fmt,
655 	.enum_framesizes = stk1135_enum_framesizes,
656 };
657 
658 /* -- module initialisation -- */
659 static const struct usb_device_id device_table[] = {
660 	{USB_DEVICE(0x174f, 0x6a31)},	/* ASUS laptop, MT9M112 sensor */
661 	{}
662 };
663 MODULE_DEVICE_TABLE(usb, device_table);
664 
665 /* -- device connect -- */
666 static int sd_probe(struct usb_interface *intf,
667 			const struct usb_device_id *id)
668 {
669 	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
670 				THIS_MODULE);
671 }
672 
673 static struct usb_driver sd_driver = {
674 	.name = MODULE_NAME,
675 	.id_table = device_table,
676 	.probe = sd_probe,
677 	.disconnect = gspca_disconnect,
678 #ifdef CONFIG_PM
679 	.suspend = gspca_suspend,
680 	.resume = gspca_resume,
681 	.reset_resume = gspca_resume,
682 #endif
683 };
684 
685 module_usb_driver(sd_driver);
686