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1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // em28xx-core.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
4 //
5 // Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
6 //		      Markus Rechberger <mrechberger@gmail.com>
7 //		      Mauro Carvalho Chehab <mchehab@kernel.org>
8 //		      Sascha Sommer <saschasommer@freenet.de>
9 // Copyright (C) 2012 Frank Schäfer <fschaefer.oss@googlemail.com>
10 //
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 2 of the License, or
14 // (at your option) any later version.
15 //
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 // GNU General Public License for more details.
20 
21 #include "em28xx.h"
22 
23 #include <linux/init.h>
24 #include <linux/jiffies.h>
25 #include <linux/list.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/usb.h>
29 #include <linux/vmalloc.h>
30 #include <sound/ac97_codec.h>
31 #include <media/v4l2-common.h>
32 
33 #define DRIVER_AUTHOR "Ludovico Cavedon <cavedon@sssup.it>, " \
34 		      "Markus Rechberger <mrechberger@gmail.com>, " \
35 		      "Mauro Carvalho Chehab <mchehab@kernel.org>, " \
36 		      "Sascha Sommer <saschasommer@freenet.de>"
37 
38 MODULE_AUTHOR(DRIVER_AUTHOR);
39 MODULE_DESCRIPTION(DRIVER_DESC);
40 MODULE_LICENSE("GPL v2");
41 MODULE_VERSION(EM28XX_VERSION);
42 
43 /* #define ENABLE_DEBUG_ISOC_FRAMES */
44 
45 static unsigned int core_debug;
46 module_param(core_debug, int, 0644);
47 MODULE_PARM_DESC(core_debug, "enable debug messages [core and isoc]");
48 
49 #define em28xx_coredbg(fmt, arg...) do {				\
50 	if (core_debug)							\
51 		dev_printk(KERN_DEBUG, &dev->intf->dev,			\
52 			   "core: %s: " fmt, __func__, ## arg);		\
53 } while (0)
54 
55 static unsigned int reg_debug;
56 module_param(reg_debug, int, 0644);
57 MODULE_PARM_DESC(reg_debug, "enable debug messages [URB reg]");
58 
59 #define em28xx_regdbg(fmt, arg...) do {				\
60 	if (reg_debug)							\
61 		dev_printk(KERN_DEBUG, &dev->intf->dev,			\
62 			   "reg: %s: " fmt, __func__, ## arg);		\
63 } while (0)
64 
65 /* FIXME: don't abuse core_debug */
66 #define em28xx_isocdbg(fmt, arg...) do {				\
67 	if (core_debug)							\
68 		dev_printk(KERN_DEBUG, &dev->intf->dev,			\
69 			   "core: %s: " fmt, __func__, ## arg);		\
70 } while (0)
71 
72 /*
73  * em28xx_read_reg_req()
74  * reads data from the usb device specifying bRequest
75  */
em28xx_read_reg_req_len(struct em28xx * dev,u8 req,u16 reg,char * buf,int len)76 int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16 reg,
77 			    char *buf, int len)
78 {
79 	int ret;
80 	struct usb_device *udev = interface_to_usbdev(dev->intf);
81 	int pipe = usb_rcvctrlpipe(udev, 0);
82 
83 	if (dev->disconnected)
84 		return -ENODEV;
85 
86 	if (len > URB_MAX_CTRL_SIZE)
87 		return -EINVAL;
88 
89 	mutex_lock(&dev->ctrl_urb_lock);
90 	ret = usb_control_msg(udev, pipe, req,
91 			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
92 			      0x0000, reg, dev->urb_buf, len, 1000);
93 	if (ret < 0) {
94 		em28xx_regdbg("(pipe 0x%08x): IN:  %02x %02x %02x %02x %02x %02x %02x %02x  failed with error %i\n",
95 			      pipe,
96 			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
97 			      req, 0, 0,
98 			      reg & 0xff, reg >> 8,
99 			      len & 0xff, len >> 8, ret);
100 		mutex_unlock(&dev->ctrl_urb_lock);
101 		return usb_translate_errors(ret);
102 	}
103 
104 	if (len)
105 		memcpy(buf, dev->urb_buf, len);
106 
107 	mutex_unlock(&dev->ctrl_urb_lock);
108 
109 	em28xx_regdbg("(pipe 0x%08x): IN:  %02x %02x %02x %02x %02x %02x %02x %02x <<< %*ph\n",
110 		      pipe, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
111 		      req, 0, 0,
112 		      reg & 0xff, reg >> 8,
113 		      len & 0xff, len >> 8, len, buf);
114 
115 	return ret;
116 }
117 
118 /*
119  * em28xx_read_reg_req()
120  * reads data from the usb device specifying bRequest
121  */
em28xx_read_reg_req(struct em28xx * dev,u8 req,u16 reg)122 int em28xx_read_reg_req(struct em28xx *dev, u8 req, u16 reg)
123 {
124 	int ret;
125 	u8 val;
126 
127 	ret = em28xx_read_reg_req_len(dev, req, reg, &val, 1);
128 	if (ret < 0)
129 		return ret;
130 
131 	return val;
132 }
133 
em28xx_read_reg(struct em28xx * dev,u16 reg)134 int em28xx_read_reg(struct em28xx *dev, u16 reg)
135 {
136 	return em28xx_read_reg_req(dev, USB_REQ_GET_STATUS, reg);
137 }
138 EXPORT_SYMBOL_GPL(em28xx_read_reg);
139 
140 /*
141  * em28xx_write_regs_req()
142  * sends data to the usb device, specifying bRequest
143  */
em28xx_write_regs_req(struct em28xx * dev,u8 req,u16 reg,char * buf,int len)144 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
145 			  int len)
146 {
147 	int ret;
148 	struct usb_device *udev = interface_to_usbdev(dev->intf);
149 	int pipe = usb_sndctrlpipe(udev, 0);
150 
151 	if (dev->disconnected)
152 		return -ENODEV;
153 
154 	if (len < 1 || len > URB_MAX_CTRL_SIZE)
155 		return -EINVAL;
156 
157 	mutex_lock(&dev->ctrl_urb_lock);
158 	memcpy(dev->urb_buf, buf, len);
159 	ret = usb_control_msg(udev, pipe, req,
160 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
161 			      0x0000, reg, dev->urb_buf, len, 1000);
162 	mutex_unlock(&dev->ctrl_urb_lock);
163 
164 	if (ret < 0) {
165 		em28xx_regdbg("(pipe 0x%08x): OUT:  %02x %02x %02x %02x %02x %02x %02x %02x >>> %*ph  failed with error %i\n",
166 			      pipe,
167 			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
168 			      req, 0, 0,
169 			      reg & 0xff, reg >> 8,
170 			      len & 0xff, len >> 8, len, buf, ret);
171 		return usb_translate_errors(ret);
172 	}
173 
174 	em28xx_regdbg("(pipe 0x%08x): OUT:  %02x %02x %02x %02x %02x %02x %02x %02x >>> %*ph\n",
175 		      pipe,
176 		      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
177 		      req, 0, 0,
178 		      reg & 0xff, reg >> 8,
179 		      len & 0xff, len >> 8, len, buf);
180 
181 	if (dev->wait_after_write)
182 		msleep(dev->wait_after_write);
183 
184 	return ret;
185 }
186 
em28xx_write_regs(struct em28xx * dev,u16 reg,char * buf,int len)187 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
188 {
189 	return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
190 }
191 EXPORT_SYMBOL_GPL(em28xx_write_regs);
192 
193 /* Write a single register */
em28xx_write_reg(struct em28xx * dev,u16 reg,u8 val)194 int em28xx_write_reg(struct em28xx *dev, u16 reg, u8 val)
195 {
196 	return em28xx_write_regs(dev, reg, &val, 1);
197 }
198 EXPORT_SYMBOL_GPL(em28xx_write_reg);
199 
200 /*
201  * em28xx_write_reg_bits()
202  * sets only some bits (specified by bitmask) of a register, by first reading
203  * the actual value
204  */
em28xx_write_reg_bits(struct em28xx * dev,u16 reg,u8 val,u8 bitmask)205 int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
206 			  u8 bitmask)
207 {
208 	int oldval;
209 	u8 newval;
210 
211 	oldval = em28xx_read_reg(dev, reg);
212 	if (oldval < 0)
213 		return oldval;
214 
215 	newval = (((u8)oldval) & ~bitmask) | (val & bitmask);
216 
217 	return em28xx_write_regs(dev, reg, &newval, 1);
218 }
219 EXPORT_SYMBOL_GPL(em28xx_write_reg_bits);
220 
221 /*
222  * em28xx_toggle_reg_bits()
223  * toggles/inverts the bits (specified by bitmask) of a register
224  */
em28xx_toggle_reg_bits(struct em28xx * dev,u16 reg,u8 bitmask)225 int em28xx_toggle_reg_bits(struct em28xx *dev, u16 reg, u8 bitmask)
226 {
227 	int oldval;
228 	u8 newval;
229 
230 	oldval = em28xx_read_reg(dev, reg);
231 	if (oldval < 0)
232 		return oldval;
233 
234 	newval = (~oldval & bitmask) | (oldval & ~bitmask);
235 
236 	return em28xx_write_reg(dev, reg, newval);
237 }
238 EXPORT_SYMBOL_GPL(em28xx_toggle_reg_bits);
239 
240 /*
241  * em28xx_is_ac97_ready()
242  * Checks if ac97 is ready
243  */
em28xx_is_ac97_ready(struct em28xx * dev)244 static int em28xx_is_ac97_ready(struct em28xx *dev)
245 {
246 	unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_AC97_XFER_TIMEOUT);
247 	int ret;
248 
249 	/* Wait up to 50 ms for AC97 command to complete */
250 	while (time_is_after_jiffies(timeout)) {
251 		ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY);
252 		if (ret < 0)
253 			return ret;
254 
255 		if (!(ret & 0x01))
256 			return 0;
257 		msleep(5);
258 	}
259 
260 	dev_warn(&dev->intf->dev,
261 		 "AC97 command still being executed: not handled properly!\n");
262 	return -EBUSY;
263 }
264 
265 /*
266  * em28xx_read_ac97()
267  * write a 16 bit value to the specified AC97 address (LSB first!)
268  */
em28xx_read_ac97(struct em28xx * dev,u8 reg)269 int em28xx_read_ac97(struct em28xx *dev, u8 reg)
270 {
271 	int ret;
272 	u8 addr = (reg & 0x7f) | 0x80;
273 	__le16 val;
274 
275 	ret = em28xx_is_ac97_ready(dev);
276 	if (ret < 0)
277 		return ret;
278 
279 	ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
280 	if (ret < 0)
281 		return ret;
282 
283 	ret = dev->em28xx_read_reg_req_len(dev, 0, EM28XX_R40_AC97LSB,
284 					   (u8 *)&val, sizeof(val));
285 
286 	if (ret < 0)
287 		return ret;
288 	return le16_to_cpu(val);
289 }
290 EXPORT_SYMBOL_GPL(em28xx_read_ac97);
291 
292 /*
293  * em28xx_write_ac97()
294  * write a 16 bit value to the specified AC97 address (LSB first!)
295  */
em28xx_write_ac97(struct em28xx * dev,u8 reg,u16 val)296 int em28xx_write_ac97(struct em28xx *dev, u8 reg, u16 val)
297 {
298 	int ret;
299 	u8 addr = reg & 0x7f;
300 	__le16 value;
301 
302 	value = cpu_to_le16(val);
303 
304 	ret = em28xx_is_ac97_ready(dev);
305 	if (ret < 0)
306 		return ret;
307 
308 	ret = em28xx_write_regs(dev, EM28XX_R40_AC97LSB, (u8 *)&value, 2);
309 	if (ret < 0)
310 		return ret;
311 
312 	ret = em28xx_write_regs(dev, EM28XX_R42_AC97ADDR, &addr, 1);
313 	if (ret < 0)
314 		return ret;
315 
316 	return 0;
317 }
318 EXPORT_SYMBOL_GPL(em28xx_write_ac97);
319 
320 struct em28xx_vol_itable {
321 	enum em28xx_amux mux;
322 	u8		 reg;
323 };
324 
325 static struct em28xx_vol_itable inputs[] = {
326 	{ EM28XX_AMUX_VIDEO,	AC97_VIDEO	},
327 	{ EM28XX_AMUX_LINE_IN,	AC97_LINE	},
328 	{ EM28XX_AMUX_PHONE,	AC97_PHONE	},
329 	{ EM28XX_AMUX_MIC,	AC97_MIC	},
330 	{ EM28XX_AMUX_CD,	AC97_CD		},
331 	{ EM28XX_AMUX_AUX,	AC97_AUX	},
332 	{ EM28XX_AMUX_PCM_OUT,	AC97_PCM	},
333 };
334 
set_ac97_input(struct em28xx * dev)335 static int set_ac97_input(struct em28xx *dev)
336 {
337 	int ret, i;
338 	enum em28xx_amux amux = dev->ctl_ainput;
339 
340 	/*
341 	 * EM28XX_AMUX_VIDEO2 is a special case used to indicate that
342 	 * em28xx should point to LINE IN, while AC97 should use VIDEO
343 	 */
344 	if (amux == EM28XX_AMUX_VIDEO2)
345 		amux = EM28XX_AMUX_VIDEO;
346 
347 	/* Mute all entres but the one that were selected */
348 	for (i = 0; i < ARRAY_SIZE(inputs); i++) {
349 		if (amux == inputs[i].mux)
350 			ret = em28xx_write_ac97(dev, inputs[i].reg, 0x0808);
351 		else
352 			ret = em28xx_write_ac97(dev, inputs[i].reg, 0x8000);
353 
354 		if (ret < 0)
355 			dev_warn(&dev->intf->dev,
356 				 "couldn't setup AC97 register %d\n",
357 				 inputs[i].reg);
358 	}
359 	return 0;
360 }
361 
em28xx_set_audio_source(struct em28xx * dev)362 static int em28xx_set_audio_source(struct em28xx *dev)
363 {
364 	int ret;
365 	u8 input;
366 
367 	if (dev->board.is_em2800) {
368 		if (dev->ctl_ainput == EM28XX_AMUX_VIDEO)
369 			input = EM2800_AUDIO_SRC_TUNER;
370 		else
371 			input = EM2800_AUDIO_SRC_LINE;
372 
373 		ret = em28xx_write_regs(dev, EM2800_R08_AUDIOSRC, &input, 1);
374 		if (ret < 0)
375 			return ret;
376 	}
377 
378 	if (dev->has_msp34xx) {
379 		input = EM28XX_AUDIO_SRC_TUNER;
380 	} else {
381 		switch (dev->ctl_ainput) {
382 		case EM28XX_AMUX_VIDEO:
383 			input = EM28XX_AUDIO_SRC_TUNER;
384 			break;
385 		default:
386 			input = EM28XX_AUDIO_SRC_LINE;
387 			break;
388 		}
389 	}
390 
391 	if (dev->board.mute_gpio && dev->mute)
392 		em28xx_gpio_set(dev, dev->board.mute_gpio);
393 	else
394 		em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);
395 
396 	ret = em28xx_write_reg_bits(dev, EM28XX_R0E_AUDIOSRC, input, 0xc0);
397 	if (ret < 0)
398 		return ret;
399 	usleep_range(10000, 11000);
400 
401 	switch (dev->audio_mode.ac97) {
402 	case EM28XX_NO_AC97:
403 		break;
404 	default:
405 		ret = set_ac97_input(dev);
406 	}
407 
408 	return ret;
409 }
410 
411 struct em28xx_vol_otable {
412 	enum em28xx_aout mux;
413 	u8		 reg;
414 };
415 
416 static const struct em28xx_vol_otable outputs[] = {
417 	{ EM28XX_AOUT_MASTER, AC97_MASTER		},
418 	{ EM28XX_AOUT_LINE,   AC97_HEADPHONE		},
419 	{ EM28XX_AOUT_MONO,   AC97_MASTER_MONO		},
420 	{ EM28XX_AOUT_LFE,    AC97_CENTER_LFE_MASTER	},
421 	{ EM28XX_AOUT_SURR,   AC97_SURROUND_MASTER	},
422 };
423 
em28xx_audio_analog_set(struct em28xx * dev)424 int em28xx_audio_analog_set(struct em28xx *dev)
425 {
426 	int ret, i;
427 	u8 xclk;
428 
429 	if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE)
430 		return 0;
431 
432 	/*
433 	 * It is assumed that all devices use master volume for output.
434 	 * It would be possible to use also line output.
435 	 */
436 	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
437 		/* Mute all outputs */
438 		for (i = 0; i < ARRAY_SIZE(outputs); i++) {
439 			ret = em28xx_write_ac97(dev, outputs[i].reg, 0x8000);
440 			if (ret < 0)
441 				dev_warn(&dev->intf->dev,
442 					 "couldn't setup AC97 register %d\n",
443 					 outputs[i].reg);
444 		}
445 	}
446 
447 	xclk = dev->board.xclk & 0x7f;
448 	if (!dev->mute)
449 		xclk |= EM28XX_XCLK_AUDIO_UNMUTE;
450 
451 	ret = em28xx_write_reg(dev, EM28XX_R0F_XCLK, xclk);
452 	if (ret < 0)
453 		return ret;
454 	usleep_range(10000, 11000);
455 
456 	/* Selects the proper audio input */
457 	ret = em28xx_set_audio_source(dev);
458 
459 	/* Sets volume */
460 	if (dev->audio_mode.ac97 != EM28XX_NO_AC97) {
461 		int vol;
462 
463 		em28xx_write_ac97(dev, AC97_POWERDOWN, 0x4200);
464 		em28xx_write_ac97(dev, AC97_EXTENDED_STATUS, 0x0031);
465 		em28xx_write_ac97(dev, AC97_PCM_LR_ADC_RATE, 0xbb80);
466 
467 		/* LSB: left channel - both channels with the same level */
468 		vol = (0x1f - dev->volume) | ((0x1f - dev->volume) << 8);
469 
470 		/* Mute device, if needed */
471 		if (dev->mute)
472 			vol |= 0x8000;
473 
474 		/* Sets volume */
475 		for (i = 0; i < ARRAY_SIZE(outputs); i++) {
476 			if (dev->ctl_aoutput & outputs[i].mux)
477 				ret = em28xx_write_ac97(dev, outputs[i].reg,
478 							vol);
479 			if (ret < 0)
480 				dev_warn(&dev->intf->dev,
481 					 "couldn't setup AC97 register %d\n",
482 					 outputs[i].reg);
483 		}
484 
485 		if (dev->ctl_aoutput & EM28XX_AOUT_PCM_IN) {
486 			int sel = ac97_return_record_select(dev->ctl_aoutput);
487 
488 			/*
489 			 * Use the same input for both left and right
490 			 * channels
491 			 */
492 			sel |= (sel << 8);
493 
494 			em28xx_write_ac97(dev, AC97_REC_SEL, sel);
495 		}
496 	}
497 
498 	return ret;
499 }
500 EXPORT_SYMBOL_GPL(em28xx_audio_analog_set);
501 
em28xx_audio_setup(struct em28xx * dev)502 int em28xx_audio_setup(struct em28xx *dev)
503 {
504 	int vid1, vid2, feat, cfg;
505 	u32 vid = 0;
506 	u8 i2s_samplerates;
507 
508 	if (dev->chip_id == CHIP_ID_EM2870 ||
509 	    dev->chip_id == CHIP_ID_EM2874 ||
510 	    dev->chip_id == CHIP_ID_EM28174 ||
511 	    dev->chip_id == CHIP_ID_EM28178) {
512 		/* Digital only device - don't load any alsa module */
513 		dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
514 		dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
515 		return 0;
516 	}
517 
518 	/* See how this device is configured */
519 	cfg = em28xx_read_reg(dev, EM28XX_R00_CHIPCFG);
520 	dev_info(&dev->intf->dev, "Config register raw data: 0x%02x\n", cfg);
521 	if (cfg < 0) { /* Register read error */
522 		/* Be conservative */
523 		dev->int_audio_type = EM28XX_INT_AUDIO_AC97;
524 	} else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) == 0x00) {
525 		/* The device doesn't have vendor audio at all */
526 		dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
527 		dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
528 		return 0;
529 	} else if ((cfg & EM28XX_CHIPCFG_AUDIOMASK) != EM28XX_CHIPCFG_AC97) {
530 		dev->int_audio_type = EM28XX_INT_AUDIO_I2S;
531 		if (dev->chip_id < CHIP_ID_EM2860 &&
532 		    (cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
533 		    EM2820_CHIPCFG_I2S_1_SAMPRATE)
534 			i2s_samplerates = 1;
535 		else if (dev->chip_id >= CHIP_ID_EM2860 &&
536 			 (cfg & EM28XX_CHIPCFG_AUDIOMASK) ==
537 			 EM2860_CHIPCFG_I2S_5_SAMPRATES)
538 			i2s_samplerates = 5;
539 		else
540 			i2s_samplerates = 3;
541 		dev_info(&dev->intf->dev, "I2S Audio (%d sample rate(s))\n",
542 			 i2s_samplerates);
543 		/* Skip the code that does AC97 vendor detection */
544 		dev->audio_mode.ac97 = EM28XX_NO_AC97;
545 		goto init_audio;
546 	} else {
547 		dev->int_audio_type = EM28XX_INT_AUDIO_AC97;
548 	}
549 
550 	dev->audio_mode.ac97 = EM28XX_AC97_OTHER;
551 
552 	vid1 = em28xx_read_ac97(dev, AC97_VENDOR_ID1);
553 	if (vid1 < 0) {
554 		/*
555 		 * Device likely doesn't support AC97
556 		 * Note: (some) em2800 devices without eeprom reports 0x91 on
557 		 *	 CHIPCFG register, even not having an AC97 chip
558 		 */
559 		dev_warn(&dev->intf->dev,
560 			 "AC97 chip type couldn't be determined\n");
561 		dev->audio_mode.ac97 = EM28XX_NO_AC97;
562 		if (dev->usb_audio_type == EM28XX_USB_AUDIO_VENDOR)
563 			dev->usb_audio_type = EM28XX_USB_AUDIO_NONE;
564 		dev->int_audio_type = EM28XX_INT_AUDIO_NONE;
565 		goto init_audio;
566 	}
567 
568 	vid2 = em28xx_read_ac97(dev, AC97_VENDOR_ID2);
569 	if (vid2 < 0)
570 		goto init_audio;
571 
572 	vid = vid1 << 16 | vid2;
573 	dev_warn(&dev->intf->dev, "AC97 vendor ID = 0x%08x\n", vid);
574 
575 	feat = em28xx_read_ac97(dev, AC97_RESET);
576 	if (feat < 0)
577 		goto init_audio;
578 
579 	dev_warn(&dev->intf->dev, "AC97 features = 0x%04x\n", feat);
580 
581 	/* Try to identify what audio processor we have */
582 	if ((vid == 0xffffffff || vid == 0x83847650) && feat == 0x6a90)
583 		dev->audio_mode.ac97 = EM28XX_AC97_EM202;
584 	else if ((vid >> 8) == 0x838476)
585 		dev->audio_mode.ac97 = EM28XX_AC97_SIGMATEL;
586 
587 init_audio:
588 	/* Reports detected AC97 processor */
589 	switch (dev->audio_mode.ac97) {
590 	case EM28XX_NO_AC97:
591 		dev_info(&dev->intf->dev, "No AC97 audio processor\n");
592 		break;
593 	case EM28XX_AC97_EM202:
594 		dev_info(&dev->intf->dev,
595 			 "Empia 202 AC97 audio processor detected\n");
596 		break;
597 	case EM28XX_AC97_SIGMATEL:
598 		dev_info(&dev->intf->dev,
599 			 "Sigmatel audio processor detected (stac 97%02x)\n",
600 			 vid & 0xff);
601 		break;
602 	case EM28XX_AC97_OTHER:
603 		dev_warn(&dev->intf->dev,
604 			 "Unknown AC97 audio processor detected!\n");
605 		break;
606 	default:
607 		break;
608 	}
609 
610 	return em28xx_audio_analog_set(dev);
611 }
612 EXPORT_SYMBOL_GPL(em28xx_audio_setup);
613 
em28xx_find_led(struct em28xx * dev,enum em28xx_led_role role)614 const struct em28xx_led *em28xx_find_led(struct em28xx *dev,
615 					 enum em28xx_led_role role)
616 {
617 	if (dev->board.leds) {
618 		u8 k = 0;
619 
620 		while (dev->board.leds[k].role >= 0 &&
621 		       dev->board.leds[k].role < EM28XX_NUM_LED_ROLES) {
622 			if (dev->board.leds[k].role == role)
623 				return &dev->board.leds[k];
624 			k++;
625 		}
626 	}
627 	return NULL;
628 }
629 EXPORT_SYMBOL_GPL(em28xx_find_led);
630 
em28xx_capture_start(struct em28xx * dev,int start)631 int em28xx_capture_start(struct em28xx *dev, int start)
632 {
633 	int rc;
634 	const struct em28xx_led *led = NULL;
635 
636 	if (dev->chip_id == CHIP_ID_EM2874 ||
637 	    dev->chip_id == CHIP_ID_EM2884 ||
638 	    dev->chip_id == CHIP_ID_EM28174 ||
639 	    dev->chip_id == CHIP_ID_EM28178) {
640 		/* The Transport Stream Enable Register moved in em2874 */
641 		if (dev->dvb_xfer_bulk) {
642 			/* Max Tx Size = 188 * 256 = 48128 - LCM(188,512) * 2 */
643 			em28xx_write_reg(dev, (dev->ts == PRIMARY_TS) ?
644 					 EM2874_R5D_TS1_PKT_SIZE :
645 					 EM2874_R5E_TS2_PKT_SIZE,
646 					 0xff);
647 		} else {
648 			/* ISOC Maximum Transfer Size = 188 * 5 */
649 			em28xx_write_reg(dev, (dev->ts == PRIMARY_TS) ?
650 					 EM2874_R5D_TS1_PKT_SIZE :
651 					 EM2874_R5E_TS2_PKT_SIZE,
652 					 dev->dvb_max_pkt_size_isoc / 188);
653 		}
654 		if (dev->ts == PRIMARY_TS)
655 			rc = em28xx_write_reg_bits(dev,
656 						   EM2874_R5F_TS_ENABLE,
657 						   start ? EM2874_TS1_CAPTURE_ENABLE : 0x00,
658 						   EM2874_TS1_CAPTURE_ENABLE | EM2874_TS1_FILTER_ENABLE | EM2874_TS1_NULL_DISCARD);
659 		else
660 			rc = em28xx_write_reg_bits(dev,
661 						   EM2874_R5F_TS_ENABLE,
662 						   start ? EM2874_TS2_CAPTURE_ENABLE : 0x00,
663 						   EM2874_TS2_CAPTURE_ENABLE | EM2874_TS2_FILTER_ENABLE | EM2874_TS2_NULL_DISCARD);
664 	} else {
665 		/* FIXME: which is the best order? */
666 		/* video registers are sampled by VREF */
667 		rc = em28xx_write_reg_bits(dev, EM28XX_R0C_USBSUSP,
668 					   start ? 0x10 : 0x00, 0x10);
669 		if (rc < 0)
670 			return rc;
671 
672 		if (start) {
673 			if (dev->is_webcam)
674 				rc = em28xx_write_reg(dev, 0x13, 0x0c);
675 
676 			/* Enable video capture */
677 			rc = em28xx_write_reg(dev, 0x48, 0x00);
678 			if (rc < 0)
679 				return rc;
680 
681 			if (dev->mode == EM28XX_ANALOG_MODE)
682 				rc = em28xx_write_reg(dev,
683 						      EM28XX_R12_VINENABLE,
684 						      0x67);
685 			else
686 				rc = em28xx_write_reg(dev,
687 						      EM28XX_R12_VINENABLE,
688 						      0x37);
689 			if (rc < 0)
690 				return rc;
691 
692 			usleep_range(10000, 11000);
693 		} else {
694 			/* disable video capture */
695 			rc = em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x27);
696 		}
697 	}
698 
699 	if (dev->mode == EM28XX_ANALOG_MODE)
700 		led = em28xx_find_led(dev, EM28XX_LED_ANALOG_CAPTURING);
701 	else
702 		led = em28xx_find_led(dev, EM28XX_LED_DIGITAL_CAPTURING);
703 
704 	if (led)
705 		em28xx_write_reg_bits(dev, led->gpio_reg,
706 				      (!start ^ led->inverted) ?
707 				      ~led->gpio_mask : led->gpio_mask,
708 				      led->gpio_mask);
709 
710 	return rc;
711 }
712 
em28xx_gpio_set(struct em28xx * dev,const struct em28xx_reg_seq * gpio)713 int em28xx_gpio_set(struct em28xx *dev, const struct em28xx_reg_seq *gpio)
714 {
715 	int rc = 0;
716 
717 	if (!gpio)
718 		return rc;
719 
720 	if (dev->mode != EM28XX_SUSPEND) {
721 		em28xx_write_reg(dev, 0x48, 0x00);
722 		if (dev->mode == EM28XX_ANALOG_MODE)
723 			em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x67);
724 		else
725 			em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x37);
726 		usleep_range(10000, 11000);
727 	}
728 
729 	/* Send GPIO reset sequences specified at board entry */
730 	while (gpio->sleep >= 0) {
731 		if (gpio->reg >= 0) {
732 			rc = em28xx_write_reg_bits(dev,
733 						   gpio->reg,
734 						   gpio->val,
735 						   gpio->mask);
736 			if (rc < 0)
737 				return rc;
738 		}
739 		if (gpio->sleep > 0)
740 			msleep(gpio->sleep);
741 
742 		gpio++;
743 	}
744 	return rc;
745 }
746 EXPORT_SYMBOL_GPL(em28xx_gpio_set);
747 
em28xx_set_mode(struct em28xx * dev,enum em28xx_mode set_mode)748 int em28xx_set_mode(struct em28xx *dev, enum em28xx_mode set_mode)
749 {
750 	if (dev->mode == set_mode)
751 		return 0;
752 
753 	if (set_mode == EM28XX_SUSPEND) {
754 		dev->mode = set_mode;
755 
756 		/* FIXME: add suspend support for ac97 */
757 
758 		return em28xx_gpio_set(dev, dev->board.suspend_gpio);
759 	}
760 
761 	dev->mode = set_mode;
762 
763 	if (dev->mode == EM28XX_DIGITAL_MODE)
764 		return em28xx_gpio_set(dev, dev->board.dvb_gpio);
765 	else
766 		return em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);
767 }
768 EXPORT_SYMBOL_GPL(em28xx_set_mode);
769 
770 /*
771  *URB control
772  */
773 
774 /*
775  * URB completion handler for isoc/bulk transfers
776  */
em28xx_irq_callback(struct urb * urb)777 static void em28xx_irq_callback(struct urb *urb)
778 {
779 	struct em28xx *dev = urb->context;
780 	unsigned long flags;
781 	int i;
782 
783 	switch (urb->status) {
784 	case 0:             /* success */
785 	case -ETIMEDOUT:    /* NAK */
786 		break;
787 	case -ECONNRESET:   /* kill */
788 	case -ENOENT:
789 	case -ESHUTDOWN:
790 		return;
791 	default:            /* error */
792 		em28xx_isocdbg("urb completion error %d.\n", urb->status);
793 		break;
794 	}
795 
796 	/* Copy data from URB */
797 	spin_lock_irqsave(&dev->slock, flags);
798 	dev->usb_ctl.urb_data_copy(dev, urb);
799 	spin_unlock_irqrestore(&dev->slock, flags);
800 
801 	/* Reset urb buffers */
802 	for (i = 0; i < urb->number_of_packets; i++) {
803 		/* isoc only (bulk: number_of_packets = 0) */
804 		urb->iso_frame_desc[i].status = 0;
805 		urb->iso_frame_desc[i].actual_length = 0;
806 	}
807 	urb->status = 0;
808 
809 	urb->status = usb_submit_urb(urb, GFP_ATOMIC);
810 	if (urb->status) {
811 		em28xx_isocdbg("urb resubmit failed (error=%i)\n",
812 			       urb->status);
813 	}
814 }
815 
816 /*
817  * Stop and Deallocate URBs
818  */
em28xx_uninit_usb_xfer(struct em28xx * dev,enum em28xx_mode mode)819 void em28xx_uninit_usb_xfer(struct em28xx *dev, enum em28xx_mode mode)
820 {
821 	struct urb *urb;
822 	struct em28xx_usb_bufs *usb_bufs;
823 	int i;
824 
825 	em28xx_isocdbg("called %s in mode %d\n", __func__, mode);
826 
827 	if (mode == EM28XX_DIGITAL_MODE)
828 		usb_bufs = &dev->usb_ctl.digital_bufs;
829 	else
830 		usb_bufs = &dev->usb_ctl.analog_bufs;
831 
832 	for (i = 0; i < usb_bufs->num_bufs; i++) {
833 		urb = usb_bufs->urb[i];
834 		if (urb) {
835 			if (!irqs_disabled())
836 				usb_kill_urb(urb);
837 			else
838 				usb_unlink_urb(urb);
839 
840 			usb_free_urb(urb);
841 			usb_bufs->urb[i] = NULL;
842 		}
843 	}
844 
845 	kfree(usb_bufs->urb);
846 	kfree(usb_bufs->buf);
847 
848 	usb_bufs->urb = NULL;
849 	usb_bufs->buf = NULL;
850 	usb_bufs->num_bufs = 0;
851 
852 	em28xx_capture_start(dev, 0);
853 }
854 EXPORT_SYMBOL_GPL(em28xx_uninit_usb_xfer);
855 
856 /*
857  * Stop URBs
858  */
em28xx_stop_urbs(struct em28xx * dev)859 void em28xx_stop_urbs(struct em28xx *dev)
860 {
861 	int i;
862 	struct urb *urb;
863 	struct em28xx_usb_bufs *isoc_bufs = &dev->usb_ctl.digital_bufs;
864 
865 	em28xx_isocdbg("called %s\n", __func__);
866 
867 	for (i = 0; i < isoc_bufs->num_bufs; i++) {
868 		urb = isoc_bufs->urb[i];
869 		if (urb) {
870 			if (!irqs_disabled())
871 				usb_kill_urb(urb);
872 			else
873 				usb_unlink_urb(urb);
874 		}
875 	}
876 
877 	em28xx_capture_start(dev, 0);
878 }
879 EXPORT_SYMBOL_GPL(em28xx_stop_urbs);
880 
881 /*
882  * Allocate URBs
883  */
em28xx_alloc_urbs(struct em28xx * dev,enum em28xx_mode mode,int xfer_bulk,int num_bufs,int max_pkt_size,int packet_multiplier)884 int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,
885 		      int num_bufs, int max_pkt_size, int packet_multiplier)
886 {
887 	struct em28xx_usb_bufs *usb_bufs;
888 	struct urb *urb;
889 	struct usb_device *udev = interface_to_usbdev(dev->intf);
890 	int i;
891 	int sb_size, pipe;
892 	int j, k;
893 
894 	em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);
895 
896 	/*
897 	 * Check mode and if we have an endpoint for the selected
898 	 * transfer type, select buffer
899 	 */
900 	if (mode == EM28XX_DIGITAL_MODE) {
901 		if ((xfer_bulk && !dev->dvb_ep_bulk) ||
902 		    (!xfer_bulk && !dev->dvb_ep_isoc)) {
903 			dev_err(&dev->intf->dev,
904 				"no endpoint for DVB mode and transfer type %d\n",
905 				xfer_bulk > 0);
906 			return -EINVAL;
907 		}
908 		usb_bufs = &dev->usb_ctl.digital_bufs;
909 	} else if (mode == EM28XX_ANALOG_MODE) {
910 		if ((xfer_bulk && !dev->analog_ep_bulk) ||
911 		    (!xfer_bulk && !dev->analog_ep_isoc)) {
912 			dev_err(&dev->intf->dev,
913 				"no endpoint for analog mode and transfer type %d\n",
914 				xfer_bulk > 0);
915 			return -EINVAL;
916 		}
917 		usb_bufs = &dev->usb_ctl.analog_bufs;
918 	} else {
919 		dev_err(&dev->intf->dev, "invalid mode selected\n");
920 		return -EINVAL;
921 	}
922 
923 	/* De-allocates all pending stuff */
924 	em28xx_uninit_usb_xfer(dev, mode);
925 
926 	usb_bufs->num_bufs = num_bufs;
927 
928 	usb_bufs->urb = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
929 	if (!usb_bufs->urb)
930 		return -ENOMEM;
931 
932 	usb_bufs->buf = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
933 	if (!usb_bufs->buf) {
934 		kfree(usb_bufs->urb);
935 		return -ENOMEM;
936 	}
937 
938 	usb_bufs->max_pkt_size = max_pkt_size;
939 	if (xfer_bulk)
940 		usb_bufs->num_packets = 0;
941 	else
942 		usb_bufs->num_packets = packet_multiplier;
943 	dev->usb_ctl.vid_buf = NULL;
944 	dev->usb_ctl.vbi_buf = NULL;
945 
946 	sb_size = packet_multiplier * usb_bufs->max_pkt_size;
947 
948 	/* allocate urbs and transfer buffers */
949 	for (i = 0; i < usb_bufs->num_bufs; i++) {
950 		urb = usb_alloc_urb(usb_bufs->num_packets, GFP_KERNEL);
951 		if (!urb) {
952 			em28xx_uninit_usb_xfer(dev, mode);
953 			return -ENOMEM;
954 		}
955 		usb_bufs->urb[i] = urb;
956 
957 		usb_bufs->buf[i] = kzalloc(sb_size, GFP_KERNEL);
958 		if (!usb_bufs->buf[i]) {
959 			for (i--; i >= 0; i--)
960 				kfree(usb_bufs->buf[i]);
961 
962 			em28xx_uninit_usb_xfer(dev, mode);
963 			return -ENOMEM;
964 		}
965 
966 		urb->transfer_flags = URB_FREE_BUFFER;
967 
968 		if (xfer_bulk) { /* bulk */
969 			pipe = usb_rcvbulkpipe(udev,
970 					       mode == EM28XX_ANALOG_MODE ?
971 					       dev->analog_ep_bulk :
972 					       dev->dvb_ep_bulk);
973 			usb_fill_bulk_urb(urb, udev, pipe, usb_bufs->buf[i],
974 					  sb_size, em28xx_irq_callback, dev);
975 		} else { /* isoc */
976 			pipe = usb_rcvisocpipe(udev,
977 					       mode == EM28XX_ANALOG_MODE ?
978 					       dev->analog_ep_isoc :
979 					       dev->dvb_ep_isoc);
980 			usb_fill_int_urb(urb, udev, pipe, usb_bufs->buf[i],
981 					 sb_size, em28xx_irq_callback, dev, 1);
982 			urb->transfer_flags |= URB_ISO_ASAP;
983 			k = 0;
984 			for (j = 0; j < usb_bufs->num_packets; j++) {
985 				urb->iso_frame_desc[j].offset = k;
986 				urb->iso_frame_desc[j].length =
987 							usb_bufs->max_pkt_size;
988 				k += usb_bufs->max_pkt_size;
989 			}
990 		}
991 
992 		urb->number_of_packets = usb_bufs->num_packets;
993 	}
994 
995 	return 0;
996 }
997 EXPORT_SYMBOL_GPL(em28xx_alloc_urbs);
998 
999 /*
1000  * Allocate URBs and start IRQ
1001  */
em28xx_init_usb_xfer(struct em28xx * dev,enum em28xx_mode mode,int xfer_bulk,int num_bufs,int max_pkt_size,int packet_multiplier,int (* urb_data_copy)(struct em28xx * dev,struct urb * urb))1002 int em28xx_init_usb_xfer(struct em28xx *dev, enum em28xx_mode mode,
1003 			 int xfer_bulk, int num_bufs, int max_pkt_size,
1004 		    int packet_multiplier,
1005 		    int (*urb_data_copy)(struct em28xx *dev, struct urb *urb))
1006 {
1007 	struct em28xx_dmaqueue *dma_q = &dev->vidq;
1008 	struct em28xx_dmaqueue *vbi_dma_q = &dev->vbiq;
1009 	struct em28xx_usb_bufs *usb_bufs;
1010 	struct usb_device *udev = interface_to_usbdev(dev->intf);
1011 	int i;
1012 	int rc;
1013 	int alloc;
1014 
1015 	em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);
1016 
1017 	dev->usb_ctl.urb_data_copy = urb_data_copy;
1018 
1019 	if (mode == EM28XX_DIGITAL_MODE) {
1020 		usb_bufs = &dev->usb_ctl.digital_bufs;
1021 		/* no need to free/alloc usb buffers in digital mode */
1022 		alloc = 0;
1023 	} else {
1024 		usb_bufs = &dev->usb_ctl.analog_bufs;
1025 		alloc = 1;
1026 	}
1027 
1028 	if (alloc) {
1029 		rc = em28xx_alloc_urbs(dev, mode, xfer_bulk, num_bufs,
1030 				       max_pkt_size, packet_multiplier);
1031 		if (rc)
1032 			return rc;
1033 	}
1034 
1035 	if (xfer_bulk) {
1036 		rc = usb_clear_halt(udev, usb_bufs->urb[0]->pipe);
1037 		if (rc < 0) {
1038 			dev_err(&dev->intf->dev,
1039 				"failed to clear USB bulk endpoint stall/halt condition (error=%i)\n",
1040 			       rc);
1041 			em28xx_uninit_usb_xfer(dev, mode);
1042 			return rc;
1043 		}
1044 	}
1045 
1046 	init_waitqueue_head(&dma_q->wq);
1047 	init_waitqueue_head(&vbi_dma_q->wq);
1048 
1049 	em28xx_capture_start(dev, 1);
1050 
1051 	/* submit urbs and enables IRQ */
1052 	for (i = 0; i < usb_bufs->num_bufs; i++) {
1053 		rc = usb_submit_urb(usb_bufs->urb[i], GFP_KERNEL);
1054 		if (rc) {
1055 			dev_err(&dev->intf->dev,
1056 				"submit of urb %i failed (error=%i)\n", i, rc);
1057 			em28xx_uninit_usb_xfer(dev, mode);
1058 			return rc;
1059 		}
1060 	}
1061 
1062 	return 0;
1063 }
1064 EXPORT_SYMBOL_GPL(em28xx_init_usb_xfer);
1065 
1066 /*
1067  * Device control list
1068  */
1069 
1070 static LIST_HEAD(em28xx_devlist);
1071 static DEFINE_MUTEX(em28xx_devlist_mutex);
1072 
1073 /*
1074  * Extension interface
1075  */
1076 
1077 static LIST_HEAD(em28xx_extension_devlist);
1078 
em28xx_register_extension(struct em28xx_ops * ops)1079 int em28xx_register_extension(struct em28xx_ops *ops)
1080 {
1081 	struct em28xx *dev = NULL;
1082 
1083 	mutex_lock(&em28xx_devlist_mutex);
1084 	list_add_tail(&ops->next, &em28xx_extension_devlist);
1085 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
1086 		if (ops->init) {
1087 			ops->init(dev);
1088 			if (dev->dev_next)
1089 				ops->init(dev->dev_next);
1090 		}
1091 	}
1092 	mutex_unlock(&em28xx_devlist_mutex);
1093 	pr_info("em28xx: Registered (%s) extension\n", ops->name);
1094 	return 0;
1095 }
1096 EXPORT_SYMBOL(em28xx_register_extension);
1097 
em28xx_unregister_extension(struct em28xx_ops * ops)1098 void em28xx_unregister_extension(struct em28xx_ops *ops)
1099 {
1100 	struct em28xx *dev = NULL;
1101 
1102 	mutex_lock(&em28xx_devlist_mutex);
1103 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
1104 		if (ops->fini) {
1105 			if (dev->dev_next)
1106 				ops->fini(dev->dev_next);
1107 			ops->fini(dev);
1108 		}
1109 	}
1110 	list_del(&ops->next);
1111 	mutex_unlock(&em28xx_devlist_mutex);
1112 	pr_info("em28xx: Removed (%s) extension\n", ops->name);
1113 }
1114 EXPORT_SYMBOL(em28xx_unregister_extension);
1115 
em28xx_init_extension(struct em28xx * dev)1116 void em28xx_init_extension(struct em28xx *dev)
1117 {
1118 	const struct em28xx_ops *ops = NULL;
1119 
1120 	mutex_lock(&em28xx_devlist_mutex);
1121 	list_add_tail(&dev->devlist, &em28xx_devlist);
1122 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1123 		if (ops->init) {
1124 			ops->init(dev);
1125 			if (dev->dev_next)
1126 				ops->init(dev->dev_next);
1127 		}
1128 	}
1129 	mutex_unlock(&em28xx_devlist_mutex);
1130 }
1131 
em28xx_close_extension(struct em28xx * dev)1132 void em28xx_close_extension(struct em28xx *dev)
1133 {
1134 	const struct em28xx_ops *ops = NULL;
1135 
1136 	mutex_lock(&em28xx_devlist_mutex);
1137 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1138 		if (ops->fini) {
1139 			if (dev->dev_next)
1140 				ops->fini(dev->dev_next);
1141 			ops->fini(dev);
1142 		}
1143 	}
1144 	list_del(&dev->devlist);
1145 	mutex_unlock(&em28xx_devlist_mutex);
1146 }
1147 
em28xx_suspend_extension(struct em28xx * dev)1148 int em28xx_suspend_extension(struct em28xx *dev)
1149 {
1150 	const struct em28xx_ops *ops = NULL;
1151 
1152 	dev_info(&dev->intf->dev, "Suspending extensions\n");
1153 	mutex_lock(&em28xx_devlist_mutex);
1154 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1155 		if (!ops->suspend)
1156 			continue;
1157 		ops->suspend(dev);
1158 		if (dev->dev_next)
1159 			ops->suspend(dev->dev_next);
1160 	}
1161 	mutex_unlock(&em28xx_devlist_mutex);
1162 	return 0;
1163 }
1164 
em28xx_resume_extension(struct em28xx * dev)1165 int em28xx_resume_extension(struct em28xx *dev)
1166 {
1167 	const struct em28xx_ops *ops = NULL;
1168 
1169 	dev_info(&dev->intf->dev, "Resuming extensions\n");
1170 	mutex_lock(&em28xx_devlist_mutex);
1171 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1172 		if (!ops->resume)
1173 			continue;
1174 		ops->resume(dev);
1175 		if (dev->dev_next)
1176 			ops->resume(dev->dev_next);
1177 	}
1178 	mutex_unlock(&em28xx_devlist_mutex);
1179 	return 0;
1180 }
1181