| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 1 | /***************************************************************************** | 
 | 2 |  * | 
 | 3 |  * Copyright (C) 2008 Cedric Bregardis <cedric.bregardis@free.fr> and | 
 | 4 |  * Jean-Christian Hassler <jhassler@free.fr> | 
 | 5 |  * | 
 | 6 |  * This file is part of the Audiowerk2 ALSA driver | 
 | 7 |  * | 
 | 8 |  * The Audiowerk2 ALSA driver is free software; you can redistribute it and/or | 
 | 9 |  * modify it under the terms of the GNU General Public License as published by | 
 | 10 |  * the Free Software Foundation; version 2. | 
 | 11 |  * | 
 | 12 |  * The Audiowerk2 ALSA driver is distributed in the hope that it will be useful, | 
 | 13 |  * but WITHOUT ANY WARRANTY; without even the implied warranty of | 
 | 14 |  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
 | 15 |  * GNU General Public License for more details. | 
 | 16 |  * | 
 | 17 |  * You should have received a copy of the GNU General Public License | 
 | 18 |  * along with the Audiowerk2 ALSA driver; if not, write to the Free Software | 
 | 19 |  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, | 
 | 20 |  * USA. | 
 | 21 |  * | 
 | 22 |  *****************************************************************************/ | 
 | 23 |  | 
 | 24 | #define AW2_SAA7146_M | 
 | 25 |  | 
 | 26 | #include <linux/init.h> | 
 | 27 | #include <linux/pci.h> | 
 | 28 | #include <linux/slab.h> | 
 | 29 | #include <linux/interrupt.h> | 
 | 30 | #include <linux/delay.h> | 
 | 31 | #include <asm/system.h> | 
 | 32 | #include <asm/io.h> | 
 | 33 | #include <sound/core.h> | 
 | 34 | #include <sound/initval.h> | 
 | 35 | #include <sound/pcm.h> | 
 | 36 | #include <sound/pcm_params.h> | 
 | 37 |  | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 38 | #include "saa7146.h" | 
 | 39 | #include "aw2-saa7146.h" | 
 | 40 |  | 
| Takashi Iwai | 9166257 | 2008-03-10 12:19:12 +0100 | [diff] [blame] | 41 | #include "aw2-tsl.c" | 
 | 42 |  | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 43 | #define WRITEREG(value, addr) writel((value), chip->base_addr + (addr)) | 
 | 44 | #define READREG(addr) readl(chip->base_addr + (addr)) | 
 | 45 |  | 
 | 46 | static struct snd_aw2_saa7146_cb_param | 
 | 47 |  arr_substream_it_playback_cb[NB_STREAM_PLAYBACK]; | 
 | 48 | static struct snd_aw2_saa7146_cb_param | 
 | 49 |  arr_substream_it_capture_cb[NB_STREAM_CAPTURE]; | 
 | 50 |  | 
 | 51 | static int snd_aw2_saa7146_get_limit(int size); | 
 | 52 |  | 
 | 53 | /* chip-specific destructor */ | 
 | 54 | int snd_aw2_saa7146_free(struct snd_aw2_saa7146 *chip) | 
 | 55 | { | 
 | 56 | 	/* disable all irqs */ | 
 | 57 | 	WRITEREG(0, IER); | 
 | 58 |  | 
 | 59 | 	/* reset saa7146 */ | 
 | 60 | 	WRITEREG((MRST_N << 16), MC1); | 
 | 61 |  | 
 | 62 | 	/* Unset base addr */ | 
 | 63 | 	chip->base_addr = NULL; | 
 | 64 |  | 
 | 65 | 	return 0; | 
 | 66 | } | 
 | 67 |  | 
 | 68 | void snd_aw2_saa7146_setup(struct snd_aw2_saa7146 *chip, | 
 | 69 | 			   void __iomem *pci_base_addr) | 
 | 70 | { | 
 | 71 | 	/* set PCI burst/threshold | 
 | 72 |  | 
 | 73 | 	   Burst length definition | 
 | 74 | 	   VALUE    BURST LENGTH | 
 | 75 | 	   000      1 Dword | 
 | 76 | 	   001      2 Dwords | 
 | 77 | 	   010      4 Dwords | 
 | 78 | 	   011      8 Dwords | 
 | 79 | 	   100      16 Dwords | 
 | 80 | 	   101      32 Dwords | 
 | 81 | 	   110      64 Dwords | 
 | 82 | 	   111      128 Dwords | 
 | 83 |  | 
 | 84 | 	   Threshold definition | 
 | 85 | 	   VALUE    WRITE MODE              READ MODE | 
 | 86 | 	   00       1 Dword of valid data   1 empty Dword | 
 | 87 | 	   01       4 Dwords of valid data  4 empty Dwords | 
 | 88 | 	   10       8 Dwords of valid data  8 empty Dwords | 
 | 89 | 	   11       16 Dwords of valid data 16 empty Dwords */ | 
 | 90 |  | 
 | 91 | 	unsigned int acon2; | 
 | 92 | 	unsigned int acon1 = 0; | 
 | 93 | 	int i; | 
 | 94 |  | 
 | 95 | 	/* Set base addr */ | 
 | 96 | 	chip->base_addr = pci_base_addr; | 
 | 97 |  | 
 | 98 | 	/* disable all irqs */ | 
 | 99 | 	WRITEREG(0, IER); | 
 | 100 |  | 
 | 101 | 	/* reset saa7146 */ | 
 | 102 | 	WRITEREG((MRST_N << 16), MC1); | 
 | 103 |  | 
 | 104 | 	/* enable audio interface */ | 
 | 105 | #ifdef __BIG_ENDIAN | 
 | 106 | 	acon1 |= A1_SWAP; | 
 | 107 | 	acon1 |= A2_SWAP; | 
 | 108 | #endif | 
 | 109 | 	/* WS0_CTRL, WS0_SYNC: input TSL1, I2S */ | 
 | 110 |  | 
 | 111 | 	/* At initialization WS1 and WS2 are disbaled (configured as input */ | 
 | 112 | 	acon1 |= 0 * WS1_CTRL; | 
 | 113 | 	acon1 |= 0 * WS2_CTRL; | 
 | 114 |  | 
 | 115 | 	/* WS4 is not used. So it must not restart A2. | 
 | 116 | 	   This is why it is configured as output (force to low) */ | 
 | 117 | 	acon1 |= 3 * WS4_CTRL; | 
 | 118 |  | 
 | 119 | 	/* WS3_CTRL, WS3_SYNC: output TSL2, I2S */ | 
 | 120 | 	acon1 |= 2 * WS3_CTRL; | 
 | 121 |  | 
 | 122 | 	/* A1 and A2 are active and asynchronous */ | 
 | 123 | 	acon1 |= 3 * AUDIO_MODE; | 
 | 124 | 	WRITEREG(acon1, ACON1); | 
 | 125 |  | 
 | 126 | 	/* The following comes from original windows driver. | 
 | 127 | 	   It is needed to have a correct behavior of input and output | 
 | 128 | 	   simultenously, but I don't know why ! */ | 
 | 129 | 	WRITEREG(3 * (BurstA1_in) + 3 * (ThreshA1_in) + | 
 | 130 | 		 3 * (BurstA1_out) + 3 * (ThreshA1_out) + | 
 | 131 | 		 3 * (BurstA2_out) + 3 * (ThreshA2_out), PCI_BT_A); | 
 | 132 |  | 
 | 133 | 	/* enable audio port pins */ | 
 | 134 | 	WRITEREG((EAP << 16) | EAP, MC1); | 
 | 135 |  | 
 | 136 | 	/* enable I2C */ | 
 | 137 | 	WRITEREG((EI2C << 16) | EI2C, MC1); | 
 | 138 | 	/* enable interrupts */ | 
 | 139 | 	WRITEREG(A1_out | A2_out | A1_in | IIC_S | IIC_E, IER); | 
 | 140 |  | 
 | 141 | 	/* audio configuration */ | 
 | 142 | 	acon2 = A2_CLKSRC | BCLK1_OEN; | 
 | 143 | 	WRITEREG(acon2, ACON2); | 
 | 144 |  | 
 | 145 | 	/* By default use analog input */ | 
 | 146 | 	snd_aw2_saa7146_use_digital_input(chip, 0); | 
 | 147 |  | 
 | 148 | 	/* TSL setup */ | 
 | 149 | 	for (i = 0; i < 8; ++i) { | 
 | 150 | 		WRITEREG(tsl1[i], TSL1 + (i * 4)); | 
 | 151 | 		WRITEREG(tsl2[i], TSL2 + (i * 4)); | 
 | 152 | 	} | 
 | 153 |  | 
 | 154 | } | 
 | 155 |  | 
 | 156 | void snd_aw2_saa7146_pcm_init_playback(struct snd_aw2_saa7146 *chip, | 
 | 157 | 				       int stream_number, | 
 | 158 | 				       unsigned long dma_addr, | 
 | 159 | 				       unsigned long period_size, | 
 | 160 | 				       unsigned long buffer_size) | 
 | 161 | { | 
 | 162 | 	unsigned long dw_page, dw_limit; | 
 | 163 |  | 
 | 164 | 	/* Configure DMA for substream | 
 | 165 | 	   Configuration informations: ALSA has allocated continuous memory | 
 | 166 | 	   pages. So we don't need to use MMU of saa7146. | 
 | 167 | 	 */ | 
 | 168 |  | 
 | 169 | 	/* No MMU -> nothing to do with PageA1, we only configure the limit of | 
 | 170 | 	   PageAx_out register */ | 
 | 171 | 	/* Disable MMU */ | 
 | 172 | 	dw_page = (0L << 11); | 
 | 173 |  | 
 | 174 | 	/* Configure Limit for DMA access. | 
 | 175 | 	   The limit register defines an address limit, which generates | 
 | 176 | 	   an interrupt if passed by the actual PCI address pointer. | 
 | 177 | 	   '0001' means an interrupt will be generated if the lower | 
 | 178 | 	   6 bits (64 bytes) of the PCI address are zero. '0010' | 
 | 179 | 	   defines a limit of 128 bytes, '0011' one of 256 bytes, and | 
 | 180 | 	   so on up to 1 Mbyte defined by '1111'. This interrupt range | 
 | 181 | 	   can be calculated as follows: | 
 | 182 | 	   Range = 2^(5 + Limit) bytes. | 
 | 183 | 	 */ | 
 | 184 | 	dw_limit = snd_aw2_saa7146_get_limit(period_size); | 
 | 185 | 	dw_page |= (dw_limit << 4); | 
 | 186 |  | 
 | 187 | 	if (stream_number == 0) { | 
 | 188 | 		WRITEREG(dw_page, PageA2_out); | 
 | 189 |  | 
 | 190 | 		/* Base address for DMA transfert. */ | 
 | 191 | 		/* This address has been reserved by ALSA. */ | 
 | 192 | 		/* This is a physical address */ | 
 | 193 | 		WRITEREG(dma_addr, BaseA2_out); | 
 | 194 |  | 
 | 195 | 		/* Define upper limit for DMA access */ | 
 | 196 | 		WRITEREG(dma_addr + buffer_size, ProtA2_out); | 
 | 197 |  | 
 | 198 | 	} else if (stream_number == 1) { | 
 | 199 | 		WRITEREG(dw_page, PageA1_out); | 
 | 200 |  | 
 | 201 | 		/* Base address for DMA transfert. */ | 
 | 202 | 		/* This address has been reserved by ALSA. */ | 
 | 203 | 		/* This is a physical address */ | 
 | 204 | 		WRITEREG(dma_addr, BaseA1_out); | 
 | 205 |  | 
 | 206 | 		/* Define upper limit for DMA access */ | 
 | 207 | 		WRITEREG(dma_addr + buffer_size, ProtA1_out); | 
 | 208 | 	} else { | 
 | 209 | 		printk(KERN_ERR | 
 | 210 | 		       "aw2: snd_aw2_saa7146_pcm_init_playback: " | 
 | 211 | 		       "Substream number is not 0 or 1 -> not managed\n"); | 
 | 212 | 	} | 
 | 213 | } | 
 | 214 |  | 
 | 215 | void snd_aw2_saa7146_pcm_init_capture(struct snd_aw2_saa7146 *chip, | 
 | 216 | 				      int stream_number, unsigned long dma_addr, | 
 | 217 | 				      unsigned long period_size, | 
 | 218 | 				      unsigned long buffer_size) | 
 | 219 | { | 
 | 220 | 	unsigned long dw_page, dw_limit; | 
 | 221 |  | 
 | 222 | 	/* Configure DMA for substream | 
 | 223 | 	   Configuration informations: ALSA has allocated continuous memory | 
 | 224 | 	   pages. So we don't need to use MMU of saa7146. | 
 | 225 | 	 */ | 
 | 226 |  | 
 | 227 | 	/* No MMU -> nothing to do with PageA1, we only configure the limit of | 
 | 228 | 	   PageAx_out register */ | 
 | 229 | 	/* Disable MMU */ | 
 | 230 | 	dw_page = (0L << 11); | 
 | 231 |  | 
 | 232 | 	/* Configure Limit for DMA access. | 
 | 233 | 	   The limit register defines an address limit, which generates | 
 | 234 | 	   an interrupt if passed by the actual PCI address pointer. | 
 | 235 | 	   '0001' means an interrupt will be generated if the lower | 
 | 236 | 	   6 bits (64 bytes) of the PCI address are zero. '0010' | 
 | 237 | 	   defines a limit of 128 bytes, '0011' one of 256 bytes, and | 
 | 238 | 	   so on up to 1 Mbyte defined by '1111'. This interrupt range | 
 | 239 | 	   can be calculated as follows: | 
 | 240 | 	   Range = 2^(5 + Limit) bytes. | 
 | 241 | 	 */ | 
 | 242 | 	dw_limit = snd_aw2_saa7146_get_limit(period_size); | 
 | 243 | 	dw_page |= (dw_limit << 4); | 
 | 244 |  | 
 | 245 | 	if (stream_number == 0) { | 
 | 246 | 		WRITEREG(dw_page, PageA1_in); | 
 | 247 |  | 
 | 248 | 		/* Base address for DMA transfert. */ | 
 | 249 | 		/* This address has been reserved by ALSA. */ | 
 | 250 | 		/* This is a physical address */ | 
 | 251 | 		WRITEREG(dma_addr, BaseA1_in); | 
 | 252 |  | 
 | 253 | 		/* Define upper limit for DMA access  */ | 
 | 254 | 		WRITEREG(dma_addr + buffer_size, ProtA1_in); | 
 | 255 | 	} else { | 
 | 256 | 		printk(KERN_ERR | 
 | 257 | 		       "aw2: snd_aw2_saa7146_pcm_init_capture: " | 
 | 258 | 		       "Substream number is not 0 -> not managed\n"); | 
 | 259 | 	} | 
 | 260 | } | 
 | 261 |  | 
 | 262 | void snd_aw2_saa7146_define_it_playback_callback(unsigned int stream_number, | 
 | 263 | 						 snd_aw2_saa7146_it_cb | 
 | 264 | 						 p_it_callback, | 
 | 265 | 						 void *p_callback_param) | 
 | 266 | { | 
 | 267 | 	if (stream_number < NB_STREAM_PLAYBACK) { | 
 | 268 | 		arr_substream_it_playback_cb[stream_number].p_it_callback = | 
 | 269 | 		    (snd_aw2_saa7146_it_cb) p_it_callback; | 
 | 270 | 		arr_substream_it_playback_cb[stream_number].p_callback_param = | 
 | 271 | 		    (void *)p_callback_param; | 
 | 272 | 	} | 
 | 273 | } | 
 | 274 |  | 
 | 275 | void snd_aw2_saa7146_define_it_capture_callback(unsigned int stream_number, | 
 | 276 | 						snd_aw2_saa7146_it_cb | 
 | 277 | 						p_it_callback, | 
 | 278 | 						void *p_callback_param) | 
 | 279 | { | 
 | 280 | 	if (stream_number < NB_STREAM_CAPTURE) { | 
 | 281 | 		arr_substream_it_capture_cb[stream_number].p_it_callback = | 
 | 282 | 		    (snd_aw2_saa7146_it_cb) p_it_callback; | 
 | 283 | 		arr_substream_it_capture_cb[stream_number].p_callback_param = | 
 | 284 | 		    (void *)p_callback_param; | 
 | 285 | 	} | 
 | 286 | } | 
 | 287 |  | 
 | 288 | void snd_aw2_saa7146_pcm_trigger_start_playback(struct snd_aw2_saa7146 *chip, | 
 | 289 | 						int stream_number) | 
 | 290 | { | 
 | 291 | 	unsigned int acon1 = 0; | 
 | 292 | 	/* In aw8 driver, dma transfert is always active. It is | 
 | 293 | 	   started and stopped in a larger "space" */ | 
 | 294 | 	acon1 = READREG(ACON1); | 
 | 295 | 	if (stream_number == 0) { | 
 | 296 | 		WRITEREG((TR_E_A2_OUT << 16) | TR_E_A2_OUT, MC1); | 
 | 297 |  | 
 | 298 | 		/* WS2_CTRL, WS2_SYNC: output TSL2, I2S */ | 
 | 299 | 		acon1 |= 2 * WS2_CTRL; | 
 | 300 | 		WRITEREG(acon1, ACON1); | 
 | 301 |  | 
 | 302 | 	} else if (stream_number == 1) { | 
 | 303 | 		WRITEREG((TR_E_A1_OUT << 16) | TR_E_A1_OUT, MC1); | 
 | 304 |  | 
 | 305 | 		/* WS1_CTRL, WS1_SYNC: output TSL1, I2S */ | 
 | 306 | 		acon1 |= 1 * WS1_CTRL; | 
 | 307 | 		WRITEREG(acon1, ACON1); | 
 | 308 | 	} | 
 | 309 | } | 
 | 310 |  | 
 | 311 | void snd_aw2_saa7146_pcm_trigger_stop_playback(struct snd_aw2_saa7146 *chip, | 
 | 312 | 					       int stream_number) | 
 | 313 | { | 
 | 314 | 	unsigned int acon1 = 0; | 
 | 315 | 	acon1 = READREG(ACON1); | 
 | 316 | 	if (stream_number == 0) { | 
 | 317 | 		/* WS2_CTRL, WS2_SYNC: output TSL2, I2S */ | 
 | 318 | 		acon1 &= ~(3 * WS2_CTRL); | 
 | 319 | 		WRITEREG(acon1, ACON1); | 
 | 320 |  | 
 | 321 | 		WRITEREG((TR_E_A2_OUT << 16), MC1); | 
 | 322 | 	} else if (stream_number == 1) { | 
 | 323 | 		/* WS1_CTRL, WS1_SYNC: output TSL1, I2S */ | 
 | 324 | 		acon1 &= ~(3 * WS1_CTRL); | 
 | 325 | 		WRITEREG(acon1, ACON1); | 
 | 326 |  | 
 | 327 | 		WRITEREG((TR_E_A1_OUT << 16), MC1); | 
 | 328 | 	} | 
 | 329 | } | 
 | 330 |  | 
 | 331 | void snd_aw2_saa7146_pcm_trigger_start_capture(struct snd_aw2_saa7146 *chip, | 
 | 332 | 					       int stream_number) | 
 | 333 | { | 
 | 334 | 	/* In aw8 driver, dma transfert is always active. It is | 
 | 335 | 	   started and stopped in a larger "space" */ | 
 | 336 | 	if (stream_number == 0) | 
 | 337 | 		WRITEREG((TR_E_A1_IN << 16) | TR_E_A1_IN, MC1); | 
 | 338 | } | 
 | 339 |  | 
 | 340 | void snd_aw2_saa7146_pcm_trigger_stop_capture(struct snd_aw2_saa7146 *chip, | 
 | 341 | 					      int stream_number) | 
 | 342 | { | 
 | 343 | 	if (stream_number == 0) | 
 | 344 | 		WRITEREG((TR_E_A1_IN << 16), MC1); | 
 | 345 | } | 
 | 346 |  | 
 | 347 | irqreturn_t snd_aw2_saa7146_interrupt(int irq, void *dev_id) | 
 | 348 | { | 
 | 349 | 	unsigned int isr; | 
 | 350 | 	unsigned int iicsta; | 
 | 351 | 	struct snd_aw2_saa7146 *chip = dev_id; | 
 | 352 |  | 
 | 353 | 	isr = READREG(ISR); | 
 | 354 | 	if (!isr) | 
 | 355 | 		return IRQ_NONE; | 
 | 356 |  | 
 | 357 | 	WRITEREG(isr, ISR); | 
 | 358 |  | 
 | 359 | 	if (isr & (IIC_S | IIC_E)) { | 
 | 360 | 		iicsta = READREG(IICSTA); | 
 | 361 | 		WRITEREG(0x100, IICSTA); | 
 | 362 | 	} | 
 | 363 |  | 
 | 364 | 	if (isr & A1_out) { | 
 | 365 | 		if (arr_substream_it_playback_cb[1].p_it_callback != NULL) { | 
 | 366 | 			arr_substream_it_playback_cb[1]. | 
 | 367 | 			    p_it_callback(arr_substream_it_playback_cb[1]. | 
 | 368 | 					  p_callback_param); | 
 | 369 | 		} | 
 | 370 | 	} | 
 | 371 | 	if (isr & A2_out) { | 
 | 372 | 		if (arr_substream_it_playback_cb[0].p_it_callback != NULL) { | 
 | 373 | 			arr_substream_it_playback_cb[0]. | 
 | 374 | 			    p_it_callback(arr_substream_it_playback_cb[0]. | 
 | 375 | 					  p_callback_param); | 
 | 376 | 		} | 
 | 377 |  | 
 | 378 | 	} | 
 | 379 | 	if (isr & A1_in) { | 
 | 380 | 		if (arr_substream_it_capture_cb[0].p_it_callback != NULL) { | 
 | 381 | 			arr_substream_it_capture_cb[0]. | 
 | 382 | 			    p_it_callback(arr_substream_it_capture_cb[0]. | 
 | 383 | 					  p_callback_param); | 
 | 384 | 		} | 
 | 385 | 	} | 
 | 386 | 	return IRQ_HANDLED; | 
 | 387 | } | 
 | 388 |  | 
 | 389 | unsigned int snd_aw2_saa7146_get_hw_ptr_playback(struct snd_aw2_saa7146 *chip, | 
 | 390 | 						 int stream_number, | 
 | 391 | 						 unsigned char *start_addr, | 
 | 392 | 						 unsigned int buffer_size) | 
 | 393 | { | 
 | 394 | 	long pci_adp = 0; | 
 | 395 | 	size_t ptr = 0; | 
 | 396 |  | 
 | 397 | 	if (stream_number == 0) { | 
 | 398 | 		pci_adp = READREG(PCI_ADP3); | 
 | 399 | 		ptr = pci_adp - (long)start_addr; | 
 | 400 |  | 
 | 401 | 		if (ptr == buffer_size) | 
 | 402 | 			ptr = 0; | 
 | 403 | 	} | 
 | 404 | 	if (stream_number == 1) { | 
 | 405 | 		pci_adp = READREG(PCI_ADP1); | 
 | 406 | 		ptr = pci_adp - (size_t) start_addr; | 
 | 407 |  | 
 | 408 | 		if (ptr == buffer_size) | 
 | 409 | 			ptr = 0; | 
 | 410 | 	} | 
 | 411 | 	return ptr; | 
 | 412 | } | 
 | 413 |  | 
 | 414 | unsigned int snd_aw2_saa7146_get_hw_ptr_capture(struct snd_aw2_saa7146 *chip, | 
 | 415 | 						int stream_number, | 
 | 416 | 						unsigned char *start_addr, | 
 | 417 | 						unsigned int buffer_size) | 
 | 418 | { | 
 | 419 | 	size_t pci_adp = 0; | 
 | 420 | 	size_t ptr = 0; | 
 | 421 | 	if (stream_number == 0) { | 
 | 422 | 		pci_adp = READREG(PCI_ADP2); | 
 | 423 | 		ptr = pci_adp - (size_t) start_addr; | 
 | 424 |  | 
 | 425 | 		if (ptr == buffer_size) | 
 | 426 | 			ptr = 0; | 
 | 427 | 	} | 
 | 428 | 	return ptr; | 
 | 429 | } | 
 | 430 |  | 
 | 431 | void snd_aw2_saa7146_use_digital_input(struct snd_aw2_saa7146 *chip, | 
 | 432 | 				       int use_digital) | 
 | 433 | { | 
 | 434 | 	/* FIXME: switch between analog and digital input does not always work. | 
 | 435 | 	   It can produce a kind of white noise. It seams that received data | 
 | 436 | 	   are inverted sometime (endian inversion). Why ? I don't know, maybe | 
 | 437 | 	   a problem of synchronization... However for the time being I have | 
 | 438 | 	   not found the problem. Workaround: switch again (and again) between | 
 | 439 | 	   digital and analog input until it works. */ | 
 | 440 | 	if (use_digital) | 
 | 441 | 		WRITEREG(0x40, GPIO_CTRL); | 
 | 442 | 	else | 
 | 443 | 		WRITEREG(0x50, GPIO_CTRL); | 
 | 444 | } | 
 | 445 |  | 
 | 446 | int snd_aw2_saa7146_is_using_digital_input(struct snd_aw2_saa7146 *chip) | 
 | 447 | { | 
 | 448 | 	unsigned int reg_val = READREG(GPIO_CTRL); | 
 | 449 | 	if ((reg_val & 0xFF) == 0x40) | 
 | 450 | 		return 1; | 
 | 451 | 	else | 
 | 452 | 		return 0; | 
 | 453 | } | 
 | 454 |  | 
 | 455 |  | 
 | 456 | static int snd_aw2_saa7146_get_limit(int size) | 
 | 457 | { | 
 | 458 | 	int limitsize = 32; | 
 | 459 | 	int limit = 0; | 
 | 460 | 	while (limitsize < size) { | 
 | 461 | 		limitsize *= 2; | 
 | 462 | 		limit++; | 
 | 463 | 	} | 
 | 464 | 	return limit; | 
 | 465 | } |