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 if (dev->ts == PRIMARY_TS)
702 		led = em28xx_find_led(dev, EM28XX_LED_DIGITAL_CAPTURING);
703 	else
704 		led = em28xx_find_led(dev, EM28XX_LED_DIGITAL_CAPTURING_TS2);
705 
706 	if (led)
707 		em28xx_write_reg_bits(dev, led->gpio_reg,
708 				      (!start ^ led->inverted) ?
709 				      ~led->gpio_mask : led->gpio_mask,
710 				      led->gpio_mask);
711 
712 	return rc;
713 }
714 
em28xx_gpio_set(struct em28xx * dev,const struct em28xx_reg_seq * gpio)715 int em28xx_gpio_set(struct em28xx *dev, const struct em28xx_reg_seq *gpio)
716 {
717 	int rc = 0;
718 
719 	if (!gpio)
720 		return rc;
721 
722 	if (dev->mode != EM28XX_SUSPEND) {
723 		em28xx_write_reg(dev, 0x48, 0x00);
724 		if (dev->mode == EM28XX_ANALOG_MODE)
725 			em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x67);
726 		else
727 			em28xx_write_reg(dev, EM28XX_R12_VINENABLE, 0x37);
728 		usleep_range(10000, 11000);
729 	}
730 
731 	/* Send GPIO reset sequences specified at board entry */
732 	while (gpio->sleep >= 0) {
733 		if (gpio->reg >= 0) {
734 			rc = em28xx_write_reg_bits(dev,
735 						   gpio->reg,
736 						   gpio->val,
737 						   gpio->mask);
738 			if (rc < 0)
739 				return rc;
740 		}
741 		if (gpio->sleep > 0)
742 			msleep(gpio->sleep);
743 
744 		gpio++;
745 	}
746 	return rc;
747 }
748 EXPORT_SYMBOL_GPL(em28xx_gpio_set);
749 
em28xx_set_mode(struct em28xx * dev,enum em28xx_mode set_mode)750 int em28xx_set_mode(struct em28xx *dev, enum em28xx_mode set_mode)
751 {
752 	if (dev->mode == set_mode)
753 		return 0;
754 
755 	if (set_mode == EM28XX_SUSPEND) {
756 		dev->mode = set_mode;
757 
758 		/* FIXME: add suspend support for ac97 */
759 
760 		return em28xx_gpio_set(dev, dev->board.suspend_gpio);
761 	}
762 
763 	dev->mode = set_mode;
764 
765 	if (dev->mode == EM28XX_DIGITAL_MODE)
766 		return em28xx_gpio_set(dev, dev->board.dvb_gpio);
767 	else
768 		return em28xx_gpio_set(dev, INPUT(dev->ctl_input)->gpio);
769 }
770 EXPORT_SYMBOL_GPL(em28xx_set_mode);
771 
772 /*
773  *URB control
774  */
775 
776 /*
777  * URB completion handler for isoc/bulk transfers
778  */
em28xx_irq_callback(struct urb * urb)779 static void em28xx_irq_callback(struct urb *urb)
780 {
781 	struct em28xx *dev = urb->context;
782 	unsigned long flags;
783 	int i;
784 
785 	switch (urb->status) {
786 	case 0:             /* success */
787 	case -ETIMEDOUT:    /* NAK */
788 		break;
789 	case -ECONNRESET:   /* kill */
790 	case -ENOENT:
791 	case -ESHUTDOWN:
792 		return;
793 	default:            /* error */
794 		em28xx_isocdbg("urb completion error %d.\n", urb->status);
795 		break;
796 	}
797 
798 	/* Copy data from URB */
799 	spin_lock_irqsave(&dev->slock, flags);
800 	dev->usb_ctl.urb_data_copy(dev, urb);
801 	spin_unlock_irqrestore(&dev->slock, flags);
802 
803 	/* Reset urb buffers */
804 	for (i = 0; i < urb->number_of_packets; i++) {
805 		/* isoc only (bulk: number_of_packets = 0) */
806 		urb->iso_frame_desc[i].status = 0;
807 		urb->iso_frame_desc[i].actual_length = 0;
808 	}
809 	urb->status = 0;
810 
811 	urb->status = usb_submit_urb(urb, GFP_ATOMIC);
812 	if (urb->status) {
813 		em28xx_isocdbg("urb resubmit failed (error=%i)\n",
814 			       urb->status);
815 	}
816 }
817 
818 /*
819  * Stop and Deallocate URBs
820  */
em28xx_uninit_usb_xfer(struct em28xx * dev,enum em28xx_mode mode)821 void em28xx_uninit_usb_xfer(struct em28xx *dev, enum em28xx_mode mode)
822 {
823 	struct urb *urb;
824 	struct em28xx_usb_bufs *usb_bufs;
825 	int i;
826 
827 	em28xx_isocdbg("called %s in mode %d\n", __func__, mode);
828 
829 	if (mode == EM28XX_DIGITAL_MODE)
830 		usb_bufs = &dev->usb_ctl.digital_bufs;
831 	else
832 		usb_bufs = &dev->usb_ctl.analog_bufs;
833 
834 	for (i = 0; i < usb_bufs->num_bufs; i++) {
835 		urb = usb_bufs->urb[i];
836 		if (urb) {
837 			if (!irqs_disabled())
838 				usb_kill_urb(urb);
839 			else
840 				usb_unlink_urb(urb);
841 
842 			usb_free_urb(urb);
843 			usb_bufs->urb[i] = NULL;
844 		}
845 	}
846 
847 	kfree(usb_bufs->urb);
848 	kfree(usb_bufs->buf);
849 
850 	usb_bufs->urb = NULL;
851 	usb_bufs->buf = NULL;
852 	usb_bufs->num_bufs = 0;
853 
854 	em28xx_capture_start(dev, 0);
855 }
856 EXPORT_SYMBOL_GPL(em28xx_uninit_usb_xfer);
857 
858 /*
859  * Stop URBs
860  */
em28xx_stop_urbs(struct em28xx * dev)861 void em28xx_stop_urbs(struct em28xx *dev)
862 {
863 	int i;
864 	struct urb *urb;
865 	struct em28xx_usb_bufs *isoc_bufs = &dev->usb_ctl.digital_bufs;
866 
867 	em28xx_isocdbg("called %s\n", __func__);
868 
869 	for (i = 0; i < isoc_bufs->num_bufs; i++) {
870 		urb = isoc_bufs->urb[i];
871 		if (urb) {
872 			if (!irqs_disabled())
873 				usb_kill_urb(urb);
874 			else
875 				usb_unlink_urb(urb);
876 		}
877 	}
878 
879 	em28xx_capture_start(dev, 0);
880 }
881 EXPORT_SYMBOL_GPL(em28xx_stop_urbs);
882 
883 /*
884  * Allocate URBs
885  */
em28xx_alloc_urbs(struct em28xx * dev,enum em28xx_mode mode,int xfer_bulk,int num_bufs,int max_pkt_size,int packet_multiplier)886 int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,
887 		      int num_bufs, int max_pkt_size, int packet_multiplier)
888 {
889 	struct em28xx_usb_bufs *usb_bufs;
890 	struct urb *urb;
891 	struct usb_device *udev = interface_to_usbdev(dev->intf);
892 	int i;
893 	int sb_size, pipe;
894 	int j, k;
895 
896 	em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);
897 
898 	/*
899 	 * Check mode and if we have an endpoint for the selected
900 	 * transfer type, select buffer
901 	 */
902 	if (mode == EM28XX_DIGITAL_MODE) {
903 		if ((xfer_bulk && !dev->dvb_ep_bulk) ||
904 		    (!xfer_bulk && !dev->dvb_ep_isoc)) {
905 			dev_err(&dev->intf->dev,
906 				"no endpoint for DVB mode and transfer type %d\n",
907 				xfer_bulk > 0);
908 			return -EINVAL;
909 		}
910 		usb_bufs = &dev->usb_ctl.digital_bufs;
911 	} else if (mode == EM28XX_ANALOG_MODE) {
912 		if ((xfer_bulk && !dev->analog_ep_bulk) ||
913 		    (!xfer_bulk && !dev->analog_ep_isoc)) {
914 			dev_err(&dev->intf->dev,
915 				"no endpoint for analog mode and transfer type %d\n",
916 				xfer_bulk > 0);
917 			return -EINVAL;
918 		}
919 		usb_bufs = &dev->usb_ctl.analog_bufs;
920 	} else {
921 		dev_err(&dev->intf->dev, "invalid mode selected\n");
922 		return -EINVAL;
923 	}
924 
925 	/* De-allocates all pending stuff */
926 	em28xx_uninit_usb_xfer(dev, mode);
927 
928 	usb_bufs->num_bufs = num_bufs;
929 
930 	usb_bufs->urb = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
931 	if (!usb_bufs->urb)
932 		return -ENOMEM;
933 
934 	usb_bufs->buf = kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
935 	if (!usb_bufs->buf) {
936 		kfree(usb_bufs->urb);
937 		return -ENOMEM;
938 	}
939 
940 	usb_bufs->max_pkt_size = max_pkt_size;
941 	if (xfer_bulk)
942 		usb_bufs->num_packets = 0;
943 	else
944 		usb_bufs->num_packets = packet_multiplier;
945 	dev->usb_ctl.vid_buf = NULL;
946 	dev->usb_ctl.vbi_buf = NULL;
947 
948 	sb_size = packet_multiplier * usb_bufs->max_pkt_size;
949 
950 	/* allocate urbs and transfer buffers */
951 	for (i = 0; i < usb_bufs->num_bufs; i++) {
952 		urb = usb_alloc_urb(usb_bufs->num_packets, GFP_KERNEL);
953 		if (!urb) {
954 			em28xx_uninit_usb_xfer(dev, mode);
955 			return -ENOMEM;
956 		}
957 		usb_bufs->urb[i] = urb;
958 
959 		usb_bufs->buf[i] = kzalloc(sb_size, GFP_KERNEL);
960 		if (!usb_bufs->buf[i]) {
961 			for (i--; i >= 0; i--)
962 				kfree(usb_bufs->buf[i]);
963 
964 			em28xx_uninit_usb_xfer(dev, mode);
965 			return -ENOMEM;
966 		}
967 
968 		urb->transfer_flags = URB_FREE_BUFFER;
969 
970 		if (xfer_bulk) { /* bulk */
971 			pipe = usb_rcvbulkpipe(udev,
972 					       mode == EM28XX_ANALOG_MODE ?
973 					       dev->analog_ep_bulk :
974 					       dev->dvb_ep_bulk);
975 			usb_fill_bulk_urb(urb, udev, pipe, usb_bufs->buf[i],
976 					  sb_size, em28xx_irq_callback, dev);
977 		} else { /* isoc */
978 			pipe = usb_rcvisocpipe(udev,
979 					       mode == EM28XX_ANALOG_MODE ?
980 					       dev->analog_ep_isoc :
981 					       dev->dvb_ep_isoc);
982 			usb_fill_int_urb(urb, udev, pipe, usb_bufs->buf[i],
983 					 sb_size, em28xx_irq_callback, dev, 1);
984 			urb->transfer_flags |= URB_ISO_ASAP;
985 			k = 0;
986 			for (j = 0; j < usb_bufs->num_packets; j++) {
987 				urb->iso_frame_desc[j].offset = k;
988 				urb->iso_frame_desc[j].length =
989 							usb_bufs->max_pkt_size;
990 				k += usb_bufs->max_pkt_size;
991 			}
992 		}
993 
994 		urb->number_of_packets = usb_bufs->num_packets;
995 	}
996 
997 	return 0;
998 }
999 EXPORT_SYMBOL_GPL(em28xx_alloc_urbs);
1000 
1001 /*
1002  * Allocate URBs and start IRQ
1003  */
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))1004 int em28xx_init_usb_xfer(struct em28xx *dev, enum em28xx_mode mode,
1005 			 int xfer_bulk, int num_bufs, int max_pkt_size,
1006 		    int packet_multiplier,
1007 		    int (*urb_data_copy)(struct em28xx *dev, struct urb *urb))
1008 {
1009 	struct em28xx_dmaqueue *dma_q = &dev->vidq;
1010 	struct em28xx_dmaqueue *vbi_dma_q = &dev->vbiq;
1011 	struct em28xx_usb_bufs *usb_bufs;
1012 	struct usb_device *udev = interface_to_usbdev(dev->intf);
1013 	int i;
1014 	int rc;
1015 	int alloc;
1016 
1017 	em28xx_isocdbg("em28xx: called %s in mode %d\n", __func__, mode);
1018 
1019 	dev->usb_ctl.urb_data_copy = urb_data_copy;
1020 
1021 	if (mode == EM28XX_DIGITAL_MODE) {
1022 		usb_bufs = &dev->usb_ctl.digital_bufs;
1023 		/* no need to free/alloc usb buffers in digital mode */
1024 		alloc = 0;
1025 	} else {
1026 		usb_bufs = &dev->usb_ctl.analog_bufs;
1027 		alloc = 1;
1028 	}
1029 
1030 	if (alloc) {
1031 		rc = em28xx_alloc_urbs(dev, mode, xfer_bulk, num_bufs,
1032 				       max_pkt_size, packet_multiplier);
1033 		if (rc)
1034 			return rc;
1035 	}
1036 
1037 	if (xfer_bulk) {
1038 		rc = usb_clear_halt(udev, usb_bufs->urb[0]->pipe);
1039 		if (rc < 0) {
1040 			dev_err(&dev->intf->dev,
1041 				"failed to clear USB bulk endpoint stall/halt condition (error=%i)\n",
1042 			       rc);
1043 			em28xx_uninit_usb_xfer(dev, mode);
1044 			return rc;
1045 		}
1046 	}
1047 
1048 	init_waitqueue_head(&dma_q->wq);
1049 	init_waitqueue_head(&vbi_dma_q->wq);
1050 
1051 	em28xx_capture_start(dev, 1);
1052 
1053 	/* submit urbs and enables IRQ */
1054 	for (i = 0; i < usb_bufs->num_bufs; i++) {
1055 		rc = usb_submit_urb(usb_bufs->urb[i], GFP_KERNEL);
1056 		if (rc) {
1057 			dev_err(&dev->intf->dev,
1058 				"submit of urb %i failed (error=%i)\n", i, rc);
1059 			em28xx_uninit_usb_xfer(dev, mode);
1060 			return rc;
1061 		}
1062 	}
1063 
1064 	return 0;
1065 }
1066 EXPORT_SYMBOL_GPL(em28xx_init_usb_xfer);
1067 
1068 /*
1069  * Device control list
1070  */
1071 
1072 static LIST_HEAD(em28xx_devlist);
1073 static DEFINE_MUTEX(em28xx_devlist_mutex);
1074 
1075 /*
1076  * Extension interface
1077  */
1078 
1079 static LIST_HEAD(em28xx_extension_devlist);
1080 
em28xx_register_extension(struct em28xx_ops * ops)1081 int em28xx_register_extension(struct em28xx_ops *ops)
1082 {
1083 	struct em28xx *dev = NULL;
1084 
1085 	mutex_lock(&em28xx_devlist_mutex);
1086 	list_add_tail(&ops->next, &em28xx_extension_devlist);
1087 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
1088 		if (ops->init) {
1089 			ops->init(dev);
1090 			if (dev->dev_next)
1091 				ops->init(dev->dev_next);
1092 		}
1093 	}
1094 	mutex_unlock(&em28xx_devlist_mutex);
1095 	pr_info("em28xx: Registered (%s) extension\n", ops->name);
1096 	return 0;
1097 }
1098 EXPORT_SYMBOL(em28xx_register_extension);
1099 
em28xx_unregister_extension(struct em28xx_ops * ops)1100 void em28xx_unregister_extension(struct em28xx_ops *ops)
1101 {
1102 	struct em28xx *dev = NULL;
1103 
1104 	mutex_lock(&em28xx_devlist_mutex);
1105 	list_for_each_entry(dev, &em28xx_devlist, devlist) {
1106 		if (ops->fini) {
1107 			if (dev->dev_next)
1108 				ops->fini(dev->dev_next);
1109 			ops->fini(dev);
1110 		}
1111 	}
1112 	list_del(&ops->next);
1113 	mutex_unlock(&em28xx_devlist_mutex);
1114 	pr_info("em28xx: Removed (%s) extension\n", ops->name);
1115 }
1116 EXPORT_SYMBOL(em28xx_unregister_extension);
1117 
em28xx_init_extension(struct em28xx * dev)1118 void em28xx_init_extension(struct em28xx *dev)
1119 {
1120 	const struct em28xx_ops *ops = NULL;
1121 
1122 	mutex_lock(&em28xx_devlist_mutex);
1123 	list_add_tail(&dev->devlist, &em28xx_devlist);
1124 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1125 		if (ops->init) {
1126 			ops->init(dev);
1127 			if (dev->dev_next)
1128 				ops->init(dev->dev_next);
1129 		}
1130 	}
1131 	mutex_unlock(&em28xx_devlist_mutex);
1132 }
1133 
em28xx_close_extension(struct em28xx * dev)1134 void em28xx_close_extension(struct em28xx *dev)
1135 {
1136 	const struct em28xx_ops *ops = NULL;
1137 
1138 	mutex_lock(&em28xx_devlist_mutex);
1139 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1140 		if (ops->fini) {
1141 			if (dev->dev_next)
1142 				ops->fini(dev->dev_next);
1143 			ops->fini(dev);
1144 		}
1145 	}
1146 	list_del(&dev->devlist);
1147 	mutex_unlock(&em28xx_devlist_mutex);
1148 }
1149 
em28xx_suspend_extension(struct em28xx * dev)1150 int em28xx_suspend_extension(struct em28xx *dev)
1151 {
1152 	const struct em28xx_ops *ops = NULL;
1153 
1154 	dev_info(&dev->intf->dev, "Suspending extensions\n");
1155 	mutex_lock(&em28xx_devlist_mutex);
1156 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1157 		if (!ops->suspend)
1158 			continue;
1159 		ops->suspend(dev);
1160 		if (dev->dev_next)
1161 			ops->suspend(dev->dev_next);
1162 	}
1163 	mutex_unlock(&em28xx_devlist_mutex);
1164 	return 0;
1165 }
1166 
em28xx_resume_extension(struct em28xx * dev)1167 int em28xx_resume_extension(struct em28xx *dev)
1168 {
1169 	const struct em28xx_ops *ops = NULL;
1170 
1171 	dev_info(&dev->intf->dev, "Resuming extensions\n");
1172 	mutex_lock(&em28xx_devlist_mutex);
1173 	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
1174 		if (!ops->resume)
1175 			continue;
1176 		ops->resume(dev);
1177 		if (dev->dev_next)
1178 			ops->resume(dev->dev_next);
1179 	}
1180 	mutex_unlock(&em28xx_devlist_mutex);
1181 	return 0;
1182 }
1183