xref: /openbmc/linux/drivers/media/usb/gspca/stk1135.c (revision bbecb07f)
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 	PDEBUG(D_USBI, "reg_r 0x%x=0x%02x", index, gspca_dev->usb_buf[0]);
71 	if (ret < 0) {
72 		pr_err("reg_r 0x%x err %d\n", index, ret);
73 		gspca_dev->usb_err = ret;
74 		return 0;
75 	}
76 
77 	return gspca_dev->usb_buf[0];
78 }
79 
80 /* -- write a register -- */
81 static void reg_w(struct gspca_dev *gspca_dev, u16 index, u8 val)
82 {
83 	int ret;
84 	struct usb_device *dev = gspca_dev->dev;
85 
86 	if (gspca_dev->usb_err < 0)
87 		return;
88 	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
89 			0x01,
90 			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
91 			val,
92 			index,
93 			NULL,
94 			0,
95 			500);
96 	PDEBUG(D_USBO, "reg_w 0x%x:=0x%02x", index, val);
97 	if (ret < 0) {
98 		pr_err("reg_w 0x%x err %d\n", index, ret);
99 		gspca_dev->usb_err = ret;
100 	}
101 }
102 
103 static void reg_w_mask(struct gspca_dev *gspca_dev, u16 index, u8 val, u8 mask)
104 {
105 	val = (reg_r(gspca_dev, index) & ~mask) | (val & mask);
106 	reg_w(gspca_dev, index, val);
107 }
108 
109 /* this function is called at probe time */
110 static int sd_config(struct gspca_dev *gspca_dev,
111 			const struct usb_device_id *id)
112 {
113 	gspca_dev->cam.cam_mode = stk1135_modes;
114 	gspca_dev->cam.nmodes = ARRAY_SIZE(stk1135_modes);
115 	return 0;
116 }
117 
118 static int stk1135_serial_wait_ready(struct gspca_dev *gspca_dev)
119 {
120 	int i = 0;
121 	u8 val;
122 
123 	do {
124 		val = reg_r(gspca_dev, STK1135_REG_SICTL + 1);
125 		if (i++ > 500) { /* maximum retry count */
126 			pr_err("serial bus timeout: status=0x%02x\n", val);
127 			return -1;
128 		}
129 	/* repeat if BUSY or WRITE/READ not finished */
130 	} while ((val & 0x10) || !(val & 0x05));
131 
132 	return 0;
133 }
134 
135 static u8 sensor_read_8(struct gspca_dev *gspca_dev, u8 addr)
136 {
137 	reg_w(gspca_dev, STK1135_REG_SBUSR, addr);
138 	/* begin read */
139 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x20);
140 	/* wait until finished */
141 	if (stk1135_serial_wait_ready(gspca_dev)) {
142 		pr_err("Sensor read failed\n");
143 		return 0;
144 	}
145 
146 	return reg_r(gspca_dev, STK1135_REG_SBUSR + 1);
147 }
148 
149 static u16 sensor_read_16(struct gspca_dev *gspca_dev, u8 addr)
150 {
151 	return (sensor_read_8(gspca_dev, addr) << 8) |
152 		sensor_read_8(gspca_dev, 0xf1);
153 }
154 
155 static void sensor_write_8(struct gspca_dev *gspca_dev, u8 addr, u8 data)
156 {
157 	/* load address and data registers */
158 	reg_w(gspca_dev, STK1135_REG_SBUSW, addr);
159 	reg_w(gspca_dev, STK1135_REG_SBUSW + 1, data);
160 	/* begin write */
161 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x01);
162 	/* wait until finished */
163 	if (stk1135_serial_wait_ready(gspca_dev)) {
164 		pr_err("Sensor write failed\n");
165 		return;
166 	}
167 }
168 
169 static void sensor_write_16(struct gspca_dev *gspca_dev, u8 addr, u16 data)
170 {
171 	sensor_write_8(gspca_dev, addr, data >> 8);
172 	sensor_write_8(gspca_dev, 0xf1, data & 0xff);
173 }
174 
175 static void sensor_set_page(struct gspca_dev *gspca_dev, u8 page)
176 {
177 	struct sd *sd = (struct sd *) gspca_dev;
178 
179 	if (page != sd->sensor_page) {
180 		sensor_write_16(gspca_dev, 0xf0, page);
181 		sd->sensor_page = page;
182 	}
183 }
184 
185 static u16 sensor_read(struct gspca_dev *gspca_dev, u16 reg)
186 {
187 	sensor_set_page(gspca_dev, reg >> 8);
188 	return sensor_read_16(gspca_dev, reg & 0xff);
189 }
190 
191 static void sensor_write(struct gspca_dev *gspca_dev, u16 reg, u16 val)
192 {
193 	sensor_set_page(gspca_dev, reg >> 8);
194 	sensor_write_16(gspca_dev, reg & 0xff, val);
195 }
196 
197 static void sensor_write_mask(struct gspca_dev *gspca_dev,
198 			u16 reg, u16 val, u16 mask)
199 {
200 	val = (sensor_read(gspca_dev, reg) & ~mask) | (val & mask);
201 	sensor_write(gspca_dev, reg, val);
202 }
203 
204 struct sensor_val {
205 	u16 reg;
206 	u16 val;
207 };
208 
209 /* configure MT9M112 sensor */
210 static void stk1135_configure_mt9m112(struct gspca_dev *gspca_dev)
211 {
212 	static const struct sensor_val cfg[] = {
213 		/* restart&reset, chip enable, reserved */
214 		{ 0x00d, 0x000b }, { 0x00d, 0x0008 }, { 0x035, 0x0022 },
215 		/* mode ctl: AWB on, AE both, clip aper corr, defect corr, AE */
216 		{ 0x106, 0x700e },
217 
218 		{ 0x2dd, 0x18e0 }, /* B-R thresholds, */
219 
220 		/* AWB */
221 		{ 0x21f, 0x0180 }, /* Cb and Cr limits */
222 		{ 0x220, 0xc814 }, { 0x221, 0x8080 }, /* lum limits, RGB gain */
223 		{ 0x222, 0xa078 }, { 0x223, 0xa078 }, /* R, B limit */
224 		{ 0x224, 0x5f20 }, { 0x228, 0xea02 }, /* mtx adj lim, adv ctl */
225 		{ 0x229, 0x867a }, /* wide gates */
226 
227 		/* Color correction */
228 		/* imager gains base, delta, delta signs */
229 		{ 0x25e, 0x594c }, { 0x25f, 0x4d51 }, { 0x260, 0x0002 },
230 		/* AWB adv ctl 2, gain offs */
231 		{ 0x2ef, 0x0008 }, { 0x2f2, 0x0000 },
232 		/* base matrix signs, scale K1-5, K6-9 */
233 		{ 0x202, 0x00ee }, { 0x203, 0x3923 }, { 0x204, 0x0724 },
234 		/* base matrix coef */
235 		{ 0x209, 0x00cd }, { 0x20a, 0x0093 }, { 0x20b, 0x0004 },/*K1-3*/
236 		{ 0x20c, 0x005c }, { 0x20d, 0x00d9 }, { 0x20e, 0x0053 },/*K4-6*/
237 		{ 0x20f, 0x0008 }, { 0x210, 0x0091 }, { 0x211, 0x00cf },/*K7-9*/
238 		{ 0x215, 0x0000 }, /* delta mtx signs */
239 		/* delta matrix coef */
240 		{ 0x216, 0x0000 }, { 0x217, 0x0000 }, { 0x218, 0x0000 },/*D1-3*/
241 		{ 0x219, 0x0000 }, { 0x21a, 0x0000 }, { 0x21b, 0x0000 },/*D4-6*/
242 		{ 0x21c, 0x0000 }, { 0x21d, 0x0000 }, { 0x21e, 0x0000 },/*D7-9*/
243 		/* enable & disable manual WB to apply color corr. settings */
244 		{ 0x106, 0xf00e }, { 0x106, 0x700e },
245 
246 		/* Lens shading correction */
247 		{ 0x180, 0x0007 }, /* control */
248 		/* vertical knee 0, 2+1, 4+3 */
249 		{ 0x181, 0xde13 }, { 0x182, 0xebe2 }, { 0x183, 0x00f6 }, /* R */
250 		{ 0x184, 0xe114 }, { 0x185, 0xeadd }, { 0x186, 0xfdf6 }, /* G */
251 		{ 0x187, 0xe511 }, { 0x188, 0xede6 }, { 0x189, 0xfbf7 }, /* B */
252 		/* horizontal knee 0, 2+1, 4+3, 5 */
253 		{ 0x18a, 0xd613 }, { 0x18b, 0xedec }, /* R .. */
254 		{ 0x18c, 0xf9f2 }, { 0x18d, 0x0000 }, /* .. R */
255 		{ 0x18e, 0xd815 }, { 0x18f, 0xe9ea }, /* G .. */
256 		{ 0x190, 0xf9f1 }, { 0x191, 0x0002 }, /* .. G */
257 		{ 0x192, 0xde10 }, { 0x193, 0xefef }, /* B .. */
258 		{ 0x194, 0xfbf4 }, { 0x195, 0x0002 }, /* .. B */
259 		/* vertical knee 6+5, 8+7 */
260 		{ 0x1b6, 0x0e06 }, { 0x1b7, 0x2713 }, /* R */
261 		{ 0x1b8, 0x1106 }, { 0x1b9, 0x2713 }, /* G */
262 		{ 0x1ba, 0x0c03 }, { 0x1bb, 0x2a0f }, /* B */
263 		/* horizontal knee 7+6, 9+8, 10 */
264 		{ 0x1bc, 0x1208 }, { 0x1bd, 0x1a16 }, { 0x1be, 0x0022 }, /* R */
265 		{ 0x1bf, 0x150a }, { 0x1c0, 0x1c1a }, { 0x1c1, 0x002d }, /* G */
266 		{ 0x1c2, 0x1109 }, { 0x1c3, 0x1414 }, { 0x1c4, 0x002a }, /* B */
267 		{ 0x106, 0x740e }, /* enable lens shading correction */
268 
269 		/* Gamma correction - context A */
270 		{ 0x153, 0x0b03 }, { 0x154, 0x4722 }, { 0x155, 0xac82 },
271 		{ 0x156, 0xdac7 }, { 0x157, 0xf5e9 }, { 0x158, 0xff00 },
272 		/* Gamma correction - context B */
273 		{ 0x1dc, 0x0b03 }, { 0x1dd, 0x4722 }, { 0x1de, 0xac82 },
274 		{ 0x1df, 0xdac7 }, { 0x1e0, 0xf5e9 }, { 0x1e1, 0xff00 },
275 
276 		/* output format: RGB, invert output pixclock, output bayer */
277 		{ 0x13a, 0x4300 }, { 0x19b, 0x4300 }, /* for context A, B */
278 		{ 0x108, 0x0180 }, /* format control - enable bayer row flip */
279 
280 		{ 0x22f, 0xd100 }, { 0x29c, 0xd100 }, /* AE A, B */
281 
282 		/* default prg conf, prg ctl - by 0x2d2, prg advance - PA1 */
283 		{ 0x2d2, 0x0000 }, { 0x2cc, 0x0004 }, { 0x2cb, 0x0001 },
284 
285 		{ 0x22e, 0x0c3c }, { 0x267, 0x1010 }, /* AE tgt ctl, gain lim */
286 
287 		/* PLL */
288 		{ 0x065, 0xa000 }, /* clk ctl - enable PLL (clear bit 14) */
289 		{ 0x066, 0x2003 }, { 0x067, 0x0501 }, /* PLL M=128, N=3, P=1 */
290 		{ 0x065, 0x2000 }, /* disable PLL bypass (clear bit 15) */
291 
292 		{ 0x005, 0x01b8 }, { 0x007, 0x00d8 }, /* horiz blanking B, A */
293 
294 		/* AE line size, shutter delay limit */
295 		{ 0x239, 0x06c0 }, { 0x23b, 0x040e }, /* for context A */
296 		{ 0x23a, 0x06c0 }, { 0x23c, 0x0564 }, /* for context B */
297 		/* shutter width basis 60Hz, 50Hz */
298 		{ 0x257, 0x0208 }, { 0x258, 0x0271 }, /* for context A */
299 		{ 0x259, 0x0209 }, { 0x25a, 0x0271 }, /* for context B */
300 
301 		{ 0x25c, 0x120d }, { 0x25d, 0x1712 }, /* flicker 60Hz, 50Hz */
302 		{ 0x264, 0x5e1c }, /* reserved */
303 		/* flicker, AE gain limits, gain zone limits */
304 		{ 0x25b, 0x0003 }, { 0x236, 0x7810 }, { 0x237, 0x8304 },
305 
306 		{ 0x008, 0x0021 }, /* vert blanking A */
307 	};
308 	int i;
309 	u16 width, height;
310 
311 	for (i = 0; i < ARRAY_SIZE(cfg); i++)
312 		sensor_write(gspca_dev, cfg[i].reg, cfg[i].val);
313 
314 	/* set output size */
315 	width = gspca_dev->pixfmt.width;
316 	height = gspca_dev->pixfmt.height;
317 	if (width <= 640 && height <= 512) { /* context A (half readout speed)*/
318 		sensor_write(gspca_dev, 0x1a7, width);
319 		sensor_write(gspca_dev, 0x1aa, height);
320 		/* set read mode context A */
321 		sensor_write(gspca_dev, 0x0c8, 0x0000);
322 		/* set resize, read mode, vblank, hblank context A */
323 		sensor_write(gspca_dev, 0x2c8, 0x0000);
324 	} else { /* context B (full readout speed) */
325 		sensor_write(gspca_dev, 0x1a1, width);
326 		sensor_write(gspca_dev, 0x1a4, height);
327 		/* set read mode context B */
328 		sensor_write(gspca_dev, 0x0c8, 0x0008);
329 		/* set resize, read mode, vblank, hblank context B */
330 		sensor_write(gspca_dev, 0x2c8, 0x040b);
331 	}
332 }
333 
334 static void stk1135_configure_clock(struct gspca_dev *gspca_dev)
335 {
336 	/* configure SCLKOUT */
337 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x12);
338 	/* set 1 clock per pixel */
339 	/* and positive edge clocked pulse high when pixel counter = 0 */
340 	reg_w(gspca_dev, STK1135_REG_TCP1 + 0, 0x41);
341 	reg_w(gspca_dev, STK1135_REG_TCP1 + 1, 0x00);
342 	reg_w(gspca_dev, STK1135_REG_TCP1 + 2, 0x00);
343 	reg_w(gspca_dev, STK1135_REG_TCP1 + 3, 0x00);
344 
345 	/* enable CLKOUT for sensor */
346 	reg_w(gspca_dev, STK1135_REG_SENSO + 0, 0x10);
347 	/* disable STOP clock */
348 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x00);
349 	/* set lower 8 bits of PLL feedback divider */
350 	reg_w(gspca_dev, STK1135_REG_SENSO + 3, 0x07);
351 	/* set other PLL parameters */
352 	reg_w(gspca_dev, STK1135_REG_PLLFD, 0x06);
353 	/* enable timing generator */
354 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x80);
355 	/* enable PLL */
356 	reg_w(gspca_dev, STK1135_REG_SENSO + 2, 0x04);
357 
358 	/* set serial interface clock divider (30MHz/0x1f*16+2) = 60240 kHz) */
359 	reg_w(gspca_dev, STK1135_REG_SICTL + 2, 0x1f);
360 
361 	/* wait a while for sensor to catch up */
362 	udelay(1000);
363 }
364 
365 static void stk1135_camera_disable(struct gspca_dev *gspca_dev)
366 {
367 	/* set capture end Y position to 0 */
368 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, 0x00);
369 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, 0x00);
370 	/* disable capture */
371 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x00, 0x80);
372 
373 	/* enable sensor standby and diasble chip enable */
374 	sensor_write_mask(gspca_dev, 0x00d, 0x0004, 0x000c);
375 
376 	/* disable PLL */
377 	reg_w_mask(gspca_dev, STK1135_REG_SENSO + 2, 0x00, 0x01);
378 	/* disable timing generator */
379 	reg_w(gspca_dev, STK1135_REG_TMGEN, 0x00);
380 	/* enable STOP clock */
381 	reg_w(gspca_dev, STK1135_REG_SENSO + 1, 0x20);
382 	/* disable CLKOUT for sensor */
383 	reg_w(gspca_dev, STK1135_REG_SENSO, 0x00);
384 
385 	/* disable sensor (GPIO5) and enable GPIO0,3,6 (?) - sensor standby? */
386 	reg_w(gspca_dev, STK1135_REG_GCTRL, 0x49);
387 }
388 
389 /* this function is called at probe and resume time */
390 static int sd_init(struct gspca_dev *gspca_dev)
391 {
392 	u16 sensor_id;
393 	char *sensor_name;
394 	struct sd *sd = (struct sd *) gspca_dev;
395 
396 	/* set GPIO3,4,5,6 direction to output */
397 	reg_w(gspca_dev, STK1135_REG_GCTRL + 2, 0x78);
398 	/* enable sensor (GPIO5) */
399 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
400 	/* disable ROM interface */
401 	reg_w(gspca_dev, STK1135_REG_GCTRL + 3, 0x80);
402 	/* enable interrupts from GPIO8 (flip sensor) and GPIO9 (???) */
403 	reg_w(gspca_dev, STK1135_REG_ICTRL + 1, 0x00);
404 	reg_w(gspca_dev, STK1135_REG_ICTRL + 3, 0x03);
405 	/* enable remote wakeup from GPIO9 (???) */
406 	reg_w(gspca_dev, STK1135_REG_RMCTL + 1, 0x00);
407 	reg_w(gspca_dev, STK1135_REG_RMCTL + 3, 0x02);
408 
409 	/* reset serial interface */
410 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x80);
411 	reg_w(gspca_dev, STK1135_REG_SICTL, 0x00);
412 	/* set sensor address */
413 	reg_w(gspca_dev, STK1135_REG_SICTL + 3, 0xba);
414 	/* disable alt 2-wire serial interface */
415 	reg_w(gspca_dev, STK1135_REG_ASIC + 3, 0x00);
416 
417 	stk1135_configure_clock(gspca_dev);
418 
419 	/* read sensor ID */
420 	sd->sensor_page = 0xff;
421 	sensor_id = sensor_read(gspca_dev, 0x000);
422 
423 	switch (sensor_id) {
424 	case 0x148c:
425 		sensor_name = "MT9M112";
426 		break;
427 	default:
428 		sensor_name = "unknown";
429 	}
430 	pr_info("Detected sensor type %s (0x%x)\n", sensor_name, sensor_id);
431 
432 	stk1135_camera_disable(gspca_dev);
433 
434 	return gspca_dev->usb_err;
435 }
436 
437 /* -- start the camera -- */
438 static int sd_start(struct gspca_dev *gspca_dev)
439 {
440 	struct sd *sd = (struct sd *) gspca_dev;
441 	u16 width, height;
442 
443 	/* enable sensor (GPIO5) */
444 	reg_w(gspca_dev, STK1135_REG_GCTRL, (1 << 5));
445 
446 	stk1135_configure_clock(gspca_dev);
447 
448 	/* set capture start position X = 0, Y = 0 */
449 	reg_w(gspca_dev, STK1135_REG_CISPO + 0, 0x00);
450 	reg_w(gspca_dev, STK1135_REG_CISPO + 1, 0x00);
451 	reg_w(gspca_dev, STK1135_REG_CISPO + 2, 0x00);
452 	reg_w(gspca_dev, STK1135_REG_CISPO + 3, 0x00);
453 
454 	/* set capture end position */
455 	width = gspca_dev->pixfmt.width;
456 	height = gspca_dev->pixfmt.height;
457 	reg_w(gspca_dev, STK1135_REG_CIEPO + 0, width & 0xff);
458 	reg_w(gspca_dev, STK1135_REG_CIEPO + 1, width >> 8);
459 	reg_w(gspca_dev, STK1135_REG_CIEPO + 2, height & 0xff);
460 	reg_w(gspca_dev, STK1135_REG_CIEPO + 3, height >> 8);
461 
462 	/* set 8-bit mode */
463 	reg_w(gspca_dev, STK1135_REG_SCTRL, 0x20);
464 
465 	stk1135_configure_mt9m112(gspca_dev);
466 
467 	/* enable capture */
468 	reg_w_mask(gspca_dev, STK1135_REG_SCTRL, 0x80, 0x80);
469 
470 	if (gspca_dev->usb_err >= 0)
471 		PDEBUG(D_STREAM, "camera started alt: 0x%02x",
472 				gspca_dev->alt);
473 
474 	sd->pkt_seq = 0;
475 
476 	return gspca_dev->usb_err;
477 }
478 
479 static void sd_stopN(struct gspca_dev *gspca_dev)
480 {
481 	struct usb_device *dev = gspca_dev->dev;
482 
483 	usb_set_interface(dev, gspca_dev->iface, 0);
484 
485 	stk1135_camera_disable(gspca_dev);
486 
487 	PDEBUG(D_STREAM, "camera stopped");
488 }
489 
490 static void sd_pkt_scan(struct gspca_dev *gspca_dev,
491 			u8 *data,			/* isoc packet */
492 			int len)			/* iso packet length */
493 {
494 	struct sd *sd = (struct sd *) gspca_dev;
495 	int skip = sizeof(struct stk1135_pkt_header);
496 	bool flip;
497 	enum gspca_packet_type pkt_type = INTER_PACKET;
498 	struct stk1135_pkt_header *hdr = (void *)data;
499 	u8 seq;
500 
501 	if (len < 4) {
502 		PDEBUG(D_PACK, "received short packet (less than 4 bytes)");
503 		return;
504 	}
505 
506 	/* GPIO 8 is flip sensor (1 = normal position, 0 = flipped to back) */
507 	flip = !(le16_to_cpu(hdr->gpio) & (1 << 8));
508 	/* it's a switch, needs software debounce */
509 	if (sd->flip_status != flip)
510 		sd->flip_debounce++;
511 	else
512 		sd->flip_debounce = 0;
513 
514 	/* check sequence number (not present in new frame packets) */
515 	if (!(hdr->flags & STK1135_HDR_FRAME_START)) {
516 		seq = hdr->seq & STK1135_HDR_SEQ_MASK;
517 		if (seq != sd->pkt_seq) {
518 			PDEBUG(D_PACK, "received out-of-sequence packet");
519 			/* resync sequence and discard packet */
520 			sd->pkt_seq = seq;
521 			gspca_dev->last_packet_type = DISCARD_PACKET;
522 			return;
523 		}
524 	}
525 	sd->pkt_seq++;
526 	if (sd->pkt_seq > STK1135_HDR_SEQ_MASK)
527 		sd->pkt_seq = 0;
528 
529 	if (len == sizeof(struct stk1135_pkt_header))
530 		return;
531 
532 	if (hdr->flags & STK1135_HDR_FRAME_START) { /* new frame */
533 		skip = 8;	/* the header is longer */
534 		gspca_frame_add(gspca_dev, LAST_PACKET, data, 0);
535 		pkt_type = FIRST_PACKET;
536 	}
537 	gspca_frame_add(gspca_dev, pkt_type, data + skip, len - skip);
538 }
539 
540 static void sethflip(struct gspca_dev *gspca_dev, s32 val)
541 {
542 	struct sd *sd = (struct sd *) gspca_dev;
543 
544 	if (sd->flip_status)
545 		val = !val;
546 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0002 : 0x0000 , 0x0002);
547 }
548 
549 static void setvflip(struct gspca_dev *gspca_dev, s32 val)
550 {
551 	struct sd *sd = (struct sd *) gspca_dev;
552 
553 	if (sd->flip_status)
554 		val = !val;
555 	sensor_write_mask(gspca_dev, 0x020, val ? 0x0001 : 0x0000 , 0x0001);
556 }
557 
558 static void stk1135_dq_callback(struct gspca_dev *gspca_dev)
559 {
560 	struct sd *sd = (struct sd *) gspca_dev;
561 
562 	if (sd->flip_debounce > 100) {
563 		sd->flip_status = !sd->flip_status;
564 		sethflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->hflip));
565 		setvflip(gspca_dev, v4l2_ctrl_g_ctrl(sd->vflip));
566 	}
567 }
568 
569 static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
570 {
571 	struct gspca_dev *gspca_dev =
572 		container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
573 
574 	gspca_dev->usb_err = 0;
575 
576 	if (!gspca_dev->streaming)
577 		return 0;
578 
579 	switch (ctrl->id) {
580 	case V4L2_CID_HFLIP:
581 		sethflip(gspca_dev, ctrl->val);
582 		break;
583 	case V4L2_CID_VFLIP:
584 		setvflip(gspca_dev, ctrl->val);
585 		break;
586 	}
587 
588 	return gspca_dev->usb_err;
589 }
590 
591 static const struct v4l2_ctrl_ops sd_ctrl_ops = {
592 	.s_ctrl = sd_s_ctrl,
593 };
594 
595 static int sd_init_controls(struct gspca_dev *gspca_dev)
596 {
597 	struct sd *sd = (struct sd *) gspca_dev;
598 	struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;
599 
600 	gspca_dev->vdev.ctrl_handler = hdl;
601 	v4l2_ctrl_handler_init(hdl, 2);
602 	sd->hflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
603 			V4L2_CID_HFLIP, 0, 1, 1, 0);
604 	sd->vflip = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
605 			V4L2_CID_VFLIP, 0, 1, 1, 0);
606 
607 	if (hdl->error) {
608 		pr_err("Could not initialize controls\n");
609 		return hdl->error;
610 	}
611 	return 0;
612 }
613 
614 static void stk1135_try_fmt(struct gspca_dev *gspca_dev, struct v4l2_format *fmt)
615 {
616 	fmt->fmt.pix.width = clamp(fmt->fmt.pix.width, 32U, 1280U);
617 	fmt->fmt.pix.height = clamp(fmt->fmt.pix.height, 32U, 1024U);
618 	/* round up to even numbers */
619 	fmt->fmt.pix.width += (fmt->fmt.pix.width & 1);
620 	fmt->fmt.pix.height += (fmt->fmt.pix.height & 1);
621 
622 	fmt->fmt.pix.bytesperline = fmt->fmt.pix.width;
623 	fmt->fmt.pix.sizeimage = fmt->fmt.pix.width * fmt->fmt.pix.height;
624 }
625 
626 static int stk1135_enum_framesizes(struct gspca_dev *gspca_dev,
627 			struct v4l2_frmsizeenum *fsize)
628 {
629 	if (fsize->index != 0 || fsize->pixel_format != V4L2_PIX_FMT_SBGGR8)
630 		return -EINVAL;
631 
632 	fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
633 	fsize->stepwise.min_width = 32;
634 	fsize->stepwise.min_height = 32;
635 	fsize->stepwise.max_width = 1280;
636 	fsize->stepwise.max_height = 1024;
637 	fsize->stepwise.step_width = 2;
638 	fsize->stepwise.step_height = 2;
639 
640 	return 0;
641 }
642 
643 /* sub-driver description */
644 static const struct sd_desc sd_desc = {
645 	.name = MODULE_NAME,
646 	.config = sd_config,
647 	.init = sd_init,
648 	.init_controls = sd_init_controls,
649 	.start = sd_start,
650 	.stopN = sd_stopN,
651 	.pkt_scan = sd_pkt_scan,
652 	.dq_callback = stk1135_dq_callback,
653 	.try_fmt = stk1135_try_fmt,
654 	.enum_framesizes = stk1135_enum_framesizes,
655 };
656 
657 /* -- module initialisation -- */
658 static const struct usb_device_id device_table[] = {
659 	{USB_DEVICE(0x174f, 0x6a31)},	/* ASUS laptop, MT9M112 sensor */
660 	{}
661 };
662 MODULE_DEVICE_TABLE(usb, device_table);
663 
664 /* -- device connect -- */
665 static int sd_probe(struct usb_interface *intf,
666 			const struct usb_device_id *id)
667 {
668 	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
669 				THIS_MODULE);
670 }
671 
672 static struct usb_driver sd_driver = {
673 	.name = MODULE_NAME,
674 	.id_table = device_table,
675 	.probe = sd_probe,
676 	.disconnect = gspca_disconnect,
677 #ifdef CONFIG_PM
678 	.suspend = gspca_suspend,
679 	.resume = gspca_resume,
680 	.reset_resume = gspca_resume,
681 #endif
682 };
683 
684 module_usb_driver(sd_driver);
685