| 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> | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 28 | #include <linux/interrupt.h> | 
|  | 29 | #include <linux/delay.h> | 
|  | 30 | #include <asm/system.h> | 
|  | 31 | #include <asm/io.h> | 
|  | 32 | #include <sound/core.h> | 
|  | 33 | #include <sound/initval.h> | 
|  | 34 | #include <sound/pcm.h> | 
|  | 35 | #include <sound/pcm_params.h> | 
|  | 36 |  | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 37 | #include "saa7146.h" | 
|  | 38 | #include "aw2-saa7146.h" | 
|  | 39 |  | 
| Takashi Iwai | 9166257 | 2008-03-10 12:19:12 +0100 | [diff] [blame] | 40 | #include "aw2-tsl.c" | 
|  | 41 |  | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 42 | #define WRITEREG(value, addr) writel((value), chip->base_addr + (addr)) | 
|  | 43 | #define READREG(addr) readl(chip->base_addr + (addr)) | 
|  | 44 |  | 
|  | 45 | static struct snd_aw2_saa7146_cb_param | 
|  | 46 | arr_substream_it_playback_cb[NB_STREAM_PLAYBACK]; | 
|  | 47 | static struct snd_aw2_saa7146_cb_param | 
|  | 48 | arr_substream_it_capture_cb[NB_STREAM_CAPTURE]; | 
|  | 49 |  | 
|  | 50 | static int snd_aw2_saa7146_get_limit(int size); | 
|  | 51 |  | 
|  | 52 | /* chip-specific destructor */ | 
|  | 53 | int snd_aw2_saa7146_free(struct snd_aw2_saa7146 *chip) | 
|  | 54 | { | 
|  | 55 | /* disable all irqs */ | 
|  | 56 | WRITEREG(0, IER); | 
|  | 57 |  | 
|  | 58 | /* reset saa7146 */ | 
|  | 59 | WRITEREG((MRST_N << 16), MC1); | 
|  | 60 |  | 
|  | 61 | /* Unset base addr */ | 
|  | 62 | chip->base_addr = NULL; | 
|  | 63 |  | 
|  | 64 | return 0; | 
|  | 65 | } | 
|  | 66 |  | 
|  | 67 | void snd_aw2_saa7146_setup(struct snd_aw2_saa7146 *chip, | 
|  | 68 | void __iomem *pci_base_addr) | 
|  | 69 | { | 
|  | 70 | /* set PCI burst/threshold | 
|  | 71 |  | 
|  | 72 | Burst length definition | 
|  | 73 | VALUE    BURST LENGTH | 
|  | 74 | 000      1 Dword | 
|  | 75 | 001      2 Dwords | 
|  | 76 | 010      4 Dwords | 
|  | 77 | 011      8 Dwords | 
|  | 78 | 100      16 Dwords | 
|  | 79 | 101      32 Dwords | 
|  | 80 | 110      64 Dwords | 
|  | 81 | 111      128 Dwords | 
|  | 82 |  | 
|  | 83 | Threshold definition | 
|  | 84 | VALUE    WRITE MODE              READ MODE | 
|  | 85 | 00       1 Dword of valid data   1 empty Dword | 
|  | 86 | 01       4 Dwords of valid data  4 empty Dwords | 
|  | 87 | 10       8 Dwords of valid data  8 empty Dwords | 
|  | 88 | 11       16 Dwords of valid data 16 empty Dwords */ | 
|  | 89 |  | 
|  | 90 | unsigned int acon2; | 
|  | 91 | unsigned int acon1 = 0; | 
|  | 92 | int i; | 
|  | 93 |  | 
|  | 94 | /* Set base addr */ | 
|  | 95 | chip->base_addr = pci_base_addr; | 
|  | 96 |  | 
|  | 97 | /* disable all irqs */ | 
|  | 98 | WRITEREG(0, IER); | 
|  | 99 |  | 
|  | 100 | /* reset saa7146 */ | 
|  | 101 | WRITEREG((MRST_N << 16), MC1); | 
|  | 102 |  | 
|  | 103 | /* enable audio interface */ | 
|  | 104 | #ifdef __BIG_ENDIAN | 
|  | 105 | acon1 |= A1_SWAP; | 
|  | 106 | acon1 |= A2_SWAP; | 
|  | 107 | #endif | 
|  | 108 | /* WS0_CTRL, WS0_SYNC: input TSL1, I2S */ | 
|  | 109 |  | 
| Thadeu Lima de Souza Cascardo | 4b512d2 | 2009-04-14 23:14:10 -0300 | [diff] [blame] | 110 | /* At initialization WS1 and WS2 are disabled (configured as input) */ | 
| Cedric Bregardis | 98f2a97 | 2008-02-20 12:05:13 +0100 | [diff] [blame] | 111 | acon1 |= 0 * WS1_CTRL; | 
|  | 112 | acon1 |= 0 * WS2_CTRL; | 
|  | 113 |  | 
|  | 114 | /* WS4 is not used. So it must not restart A2. | 
|  | 115 | This is why it is configured as output (force to low) */ | 
|  | 116 | acon1 |= 3 * WS4_CTRL; | 
|  | 117 |  | 
|  | 118 | /* WS3_CTRL, WS3_SYNC: output TSL2, I2S */ | 
|  | 119 | acon1 |= 2 * WS3_CTRL; | 
|  | 120 |  | 
|  | 121 | /* A1 and A2 are active and asynchronous */ | 
|  | 122 | acon1 |= 3 * AUDIO_MODE; | 
|  | 123 | WRITEREG(acon1, ACON1); | 
|  | 124 |  | 
|  | 125 | /* The following comes from original windows driver. | 
|  | 126 | It is needed to have a correct behavior of input and output | 
|  | 127 | simultenously, but I don't know why ! */ | 
|  | 128 | WRITEREG(3 * (BurstA1_in) + 3 * (ThreshA1_in) + | 
|  | 129 | 3 * (BurstA1_out) + 3 * (ThreshA1_out) + | 
|  | 130 | 3 * (BurstA2_out) + 3 * (ThreshA2_out), PCI_BT_A); | 
|  | 131 |  | 
|  | 132 | /* enable audio port pins */ | 
|  | 133 | WRITEREG((EAP << 16) | EAP, MC1); | 
|  | 134 |  | 
|  | 135 | /* enable I2C */ | 
|  | 136 | WRITEREG((EI2C << 16) | EI2C, MC1); | 
|  | 137 | /* enable interrupts */ | 
|  | 138 | WRITEREG(A1_out | A2_out | A1_in | IIC_S | IIC_E, IER); | 
|  | 139 |  | 
|  | 140 | /* audio configuration */ | 
|  | 141 | acon2 = A2_CLKSRC | BCLK1_OEN; | 
|  | 142 | WRITEREG(acon2, ACON2); | 
|  | 143 |  | 
|  | 144 | /* By default use analog input */ | 
|  | 145 | snd_aw2_saa7146_use_digital_input(chip, 0); | 
|  | 146 |  | 
|  | 147 | /* TSL setup */ | 
|  | 148 | for (i = 0; i < 8; ++i) { | 
|  | 149 | WRITEREG(tsl1[i], TSL1 + (i * 4)); | 
|  | 150 | WRITEREG(tsl2[i], TSL2 + (i * 4)); | 
|  | 151 | } | 
|  | 152 |  | 
|  | 153 | } | 
|  | 154 |  | 
|  | 155 | void snd_aw2_saa7146_pcm_init_playback(struct snd_aw2_saa7146 *chip, | 
|  | 156 | int stream_number, | 
|  | 157 | unsigned long dma_addr, | 
|  | 158 | unsigned long period_size, | 
|  | 159 | unsigned long buffer_size) | 
|  | 160 | { | 
|  | 161 | unsigned long dw_page, dw_limit; | 
|  | 162 |  | 
|  | 163 | /* Configure DMA for substream | 
|  | 164 | Configuration informations: ALSA has allocated continuous memory | 
|  | 165 | pages. So we don't need to use MMU of saa7146. | 
|  | 166 | */ | 
|  | 167 |  | 
|  | 168 | /* No MMU -> nothing to do with PageA1, we only configure the limit of | 
|  | 169 | PageAx_out register */ | 
|  | 170 | /* Disable MMU */ | 
|  | 171 | dw_page = (0L << 11); | 
|  | 172 |  | 
|  | 173 | /* Configure Limit for DMA access. | 
|  | 174 | The limit register defines an address limit, which generates | 
|  | 175 | an interrupt if passed by the actual PCI address pointer. | 
|  | 176 | '0001' means an interrupt will be generated if the lower | 
|  | 177 | 6 bits (64 bytes) of the PCI address are zero. '0010' | 
|  | 178 | defines a limit of 128 bytes, '0011' one of 256 bytes, and | 
|  | 179 | so on up to 1 Mbyte defined by '1111'. This interrupt range | 
|  | 180 | can be calculated as follows: | 
|  | 181 | Range = 2^(5 + Limit) bytes. | 
|  | 182 | */ | 
|  | 183 | dw_limit = snd_aw2_saa7146_get_limit(period_size); | 
|  | 184 | dw_page |= (dw_limit << 4); | 
|  | 185 |  | 
|  | 186 | if (stream_number == 0) { | 
|  | 187 | WRITEREG(dw_page, PageA2_out); | 
|  | 188 |  | 
|  | 189 | /* Base address for DMA transfert. */ | 
|  | 190 | /* This address has been reserved by ALSA. */ | 
|  | 191 | /* This is a physical address */ | 
|  | 192 | WRITEREG(dma_addr, BaseA2_out); | 
|  | 193 |  | 
|  | 194 | /* Define upper limit for DMA access */ | 
|  | 195 | WRITEREG(dma_addr + buffer_size, ProtA2_out); | 
|  | 196 |  | 
|  | 197 | } else if (stream_number == 1) { | 
|  | 198 | WRITEREG(dw_page, PageA1_out); | 
|  | 199 |  | 
|  | 200 | /* Base address for DMA transfert. */ | 
|  | 201 | /* This address has been reserved by ALSA. */ | 
|  | 202 | /* This is a physical address */ | 
|  | 203 | WRITEREG(dma_addr, BaseA1_out); | 
|  | 204 |  | 
|  | 205 | /* Define upper limit for DMA access */ | 
|  | 206 | WRITEREG(dma_addr + buffer_size, ProtA1_out); | 
|  | 207 | } else { | 
|  | 208 | printk(KERN_ERR | 
|  | 209 | "aw2: snd_aw2_saa7146_pcm_init_playback: " | 
|  | 210 | "Substream number is not 0 or 1 -> not managed\n"); | 
|  | 211 | } | 
|  | 212 | } | 
|  | 213 |  | 
|  | 214 | void snd_aw2_saa7146_pcm_init_capture(struct snd_aw2_saa7146 *chip, | 
|  | 215 | int stream_number, unsigned long dma_addr, | 
|  | 216 | unsigned long period_size, | 
|  | 217 | unsigned long buffer_size) | 
|  | 218 | { | 
|  | 219 | unsigned long dw_page, dw_limit; | 
|  | 220 |  | 
|  | 221 | /* Configure DMA for substream | 
|  | 222 | Configuration informations: ALSA has allocated continuous memory | 
|  | 223 | pages. So we don't need to use MMU of saa7146. | 
|  | 224 | */ | 
|  | 225 |  | 
|  | 226 | /* No MMU -> nothing to do with PageA1, we only configure the limit of | 
|  | 227 | PageAx_out register */ | 
|  | 228 | /* Disable MMU */ | 
|  | 229 | dw_page = (0L << 11); | 
|  | 230 |  | 
|  | 231 | /* Configure Limit for DMA access. | 
|  | 232 | The limit register defines an address limit, which generates | 
|  | 233 | an interrupt if passed by the actual PCI address pointer. | 
|  | 234 | '0001' means an interrupt will be generated if the lower | 
|  | 235 | 6 bits (64 bytes) of the PCI address are zero. '0010' | 
|  | 236 | defines a limit of 128 bytes, '0011' one of 256 bytes, and | 
|  | 237 | so on up to 1 Mbyte defined by '1111'. This interrupt range | 
|  | 238 | can be calculated as follows: | 
|  | 239 | Range = 2^(5 + Limit) bytes. | 
|  | 240 | */ | 
|  | 241 | dw_limit = snd_aw2_saa7146_get_limit(period_size); | 
|  | 242 | dw_page |= (dw_limit << 4); | 
|  | 243 |  | 
|  | 244 | if (stream_number == 0) { | 
|  | 245 | WRITEREG(dw_page, PageA1_in); | 
|  | 246 |  | 
|  | 247 | /* Base address for DMA transfert. */ | 
|  | 248 | /* This address has been reserved by ALSA. */ | 
|  | 249 | /* This is a physical address */ | 
|  | 250 | WRITEREG(dma_addr, BaseA1_in); | 
|  | 251 |  | 
|  | 252 | /* Define upper limit for DMA access  */ | 
|  | 253 | WRITEREG(dma_addr + buffer_size, ProtA1_in); | 
|  | 254 | } else { | 
|  | 255 | printk(KERN_ERR | 
|  | 256 | "aw2: snd_aw2_saa7146_pcm_init_capture: " | 
|  | 257 | "Substream number is not 0 -> not managed\n"); | 
|  | 258 | } | 
|  | 259 | } | 
|  | 260 |  | 
|  | 261 | void snd_aw2_saa7146_define_it_playback_callback(unsigned int stream_number, | 
|  | 262 | snd_aw2_saa7146_it_cb | 
|  | 263 | p_it_callback, | 
|  | 264 | void *p_callback_param) | 
|  | 265 | { | 
|  | 266 | if (stream_number < NB_STREAM_PLAYBACK) { | 
|  | 267 | arr_substream_it_playback_cb[stream_number].p_it_callback = | 
|  | 268 | (snd_aw2_saa7146_it_cb) p_it_callback; | 
|  | 269 | arr_substream_it_playback_cb[stream_number].p_callback_param = | 
|  | 270 | (void *)p_callback_param; | 
|  | 271 | } | 
|  | 272 | } | 
|  | 273 |  | 
|  | 274 | void snd_aw2_saa7146_define_it_capture_callback(unsigned int stream_number, | 
|  | 275 | snd_aw2_saa7146_it_cb | 
|  | 276 | p_it_callback, | 
|  | 277 | void *p_callback_param) | 
|  | 278 | { | 
|  | 279 | if (stream_number < NB_STREAM_CAPTURE) { | 
|  | 280 | arr_substream_it_capture_cb[stream_number].p_it_callback = | 
|  | 281 | (snd_aw2_saa7146_it_cb) p_it_callback; | 
|  | 282 | arr_substream_it_capture_cb[stream_number].p_callback_param = | 
|  | 283 | (void *)p_callback_param; | 
|  | 284 | } | 
|  | 285 | } | 
|  | 286 |  | 
|  | 287 | void snd_aw2_saa7146_pcm_trigger_start_playback(struct snd_aw2_saa7146 *chip, | 
|  | 288 | int stream_number) | 
|  | 289 | { | 
|  | 290 | unsigned int acon1 = 0; | 
|  | 291 | /* In aw8 driver, dma transfert is always active. It is | 
|  | 292 | started and stopped in a larger "space" */ | 
|  | 293 | acon1 = READREG(ACON1); | 
|  | 294 | if (stream_number == 0) { | 
|  | 295 | WRITEREG((TR_E_A2_OUT << 16) | TR_E_A2_OUT, MC1); | 
|  | 296 |  | 
|  | 297 | /* WS2_CTRL, WS2_SYNC: output TSL2, I2S */ | 
|  | 298 | acon1 |= 2 * WS2_CTRL; | 
|  | 299 | WRITEREG(acon1, ACON1); | 
|  | 300 |  | 
|  | 301 | } else if (stream_number == 1) { | 
|  | 302 | WRITEREG((TR_E_A1_OUT << 16) | TR_E_A1_OUT, MC1); | 
|  | 303 |  | 
|  | 304 | /* WS1_CTRL, WS1_SYNC: output TSL1, I2S */ | 
|  | 305 | acon1 |= 1 * WS1_CTRL; | 
|  | 306 | WRITEREG(acon1, ACON1); | 
|  | 307 | } | 
|  | 308 | } | 
|  | 309 |  | 
|  | 310 | void snd_aw2_saa7146_pcm_trigger_stop_playback(struct snd_aw2_saa7146 *chip, | 
|  | 311 | int stream_number) | 
|  | 312 | { | 
|  | 313 | unsigned int acon1 = 0; | 
|  | 314 | acon1 = READREG(ACON1); | 
|  | 315 | if (stream_number == 0) { | 
|  | 316 | /* WS2_CTRL, WS2_SYNC: output TSL2, I2S */ | 
|  | 317 | acon1 &= ~(3 * WS2_CTRL); | 
|  | 318 | WRITEREG(acon1, ACON1); | 
|  | 319 |  | 
|  | 320 | WRITEREG((TR_E_A2_OUT << 16), MC1); | 
|  | 321 | } else if (stream_number == 1) { | 
|  | 322 | /* WS1_CTRL, WS1_SYNC: output TSL1, I2S */ | 
|  | 323 | acon1 &= ~(3 * WS1_CTRL); | 
|  | 324 | WRITEREG(acon1, ACON1); | 
|  | 325 |  | 
|  | 326 | WRITEREG((TR_E_A1_OUT << 16), MC1); | 
|  | 327 | } | 
|  | 328 | } | 
|  | 329 |  | 
|  | 330 | void snd_aw2_saa7146_pcm_trigger_start_capture(struct snd_aw2_saa7146 *chip, | 
|  | 331 | int stream_number) | 
|  | 332 | { | 
|  | 333 | /* In aw8 driver, dma transfert is always active. It is | 
|  | 334 | started and stopped in a larger "space" */ | 
|  | 335 | if (stream_number == 0) | 
|  | 336 | WRITEREG((TR_E_A1_IN << 16) | TR_E_A1_IN, MC1); | 
|  | 337 | } | 
|  | 338 |  | 
|  | 339 | void snd_aw2_saa7146_pcm_trigger_stop_capture(struct snd_aw2_saa7146 *chip, | 
|  | 340 | int stream_number) | 
|  | 341 | { | 
|  | 342 | if (stream_number == 0) | 
|  | 343 | WRITEREG((TR_E_A1_IN << 16), MC1); | 
|  | 344 | } | 
|  | 345 |  | 
|  | 346 | irqreturn_t snd_aw2_saa7146_interrupt(int irq, void *dev_id) | 
|  | 347 | { | 
|  | 348 | unsigned int isr; | 
|  | 349 | unsigned int iicsta; | 
|  | 350 | struct snd_aw2_saa7146 *chip = dev_id; | 
|  | 351 |  | 
|  | 352 | isr = READREG(ISR); | 
|  | 353 | if (!isr) | 
|  | 354 | return IRQ_NONE; | 
|  | 355 |  | 
|  | 356 | WRITEREG(isr, ISR); | 
|  | 357 |  | 
|  | 358 | if (isr & (IIC_S | IIC_E)) { | 
|  | 359 | iicsta = READREG(IICSTA); | 
|  | 360 | WRITEREG(0x100, IICSTA); | 
|  | 361 | } | 
|  | 362 |  | 
|  | 363 | if (isr & A1_out) { | 
|  | 364 | if (arr_substream_it_playback_cb[1].p_it_callback != NULL) { | 
|  | 365 | arr_substream_it_playback_cb[1]. | 
|  | 366 | p_it_callback(arr_substream_it_playback_cb[1]. | 
|  | 367 | p_callback_param); | 
|  | 368 | } | 
|  | 369 | } | 
|  | 370 | if (isr & A2_out) { | 
|  | 371 | if (arr_substream_it_playback_cb[0].p_it_callback != NULL) { | 
|  | 372 | arr_substream_it_playback_cb[0]. | 
|  | 373 | p_it_callback(arr_substream_it_playback_cb[0]. | 
|  | 374 | p_callback_param); | 
|  | 375 | } | 
|  | 376 |  | 
|  | 377 | } | 
|  | 378 | if (isr & A1_in) { | 
|  | 379 | if (arr_substream_it_capture_cb[0].p_it_callback != NULL) { | 
|  | 380 | arr_substream_it_capture_cb[0]. | 
|  | 381 | p_it_callback(arr_substream_it_capture_cb[0]. | 
|  | 382 | p_callback_param); | 
|  | 383 | } | 
|  | 384 | } | 
|  | 385 | return IRQ_HANDLED; | 
|  | 386 | } | 
|  | 387 |  | 
|  | 388 | unsigned int snd_aw2_saa7146_get_hw_ptr_playback(struct snd_aw2_saa7146 *chip, | 
|  | 389 | int stream_number, | 
|  | 390 | unsigned char *start_addr, | 
|  | 391 | unsigned int buffer_size) | 
|  | 392 | { | 
|  | 393 | long pci_adp = 0; | 
|  | 394 | size_t ptr = 0; | 
|  | 395 |  | 
|  | 396 | if (stream_number == 0) { | 
|  | 397 | pci_adp = READREG(PCI_ADP3); | 
|  | 398 | ptr = pci_adp - (long)start_addr; | 
|  | 399 |  | 
|  | 400 | if (ptr == buffer_size) | 
|  | 401 | ptr = 0; | 
|  | 402 | } | 
|  | 403 | if (stream_number == 1) { | 
|  | 404 | pci_adp = READREG(PCI_ADP1); | 
|  | 405 | ptr = pci_adp - (size_t) start_addr; | 
|  | 406 |  | 
|  | 407 | if (ptr == buffer_size) | 
|  | 408 | ptr = 0; | 
|  | 409 | } | 
|  | 410 | return ptr; | 
|  | 411 | } | 
|  | 412 |  | 
|  | 413 | unsigned int snd_aw2_saa7146_get_hw_ptr_capture(struct snd_aw2_saa7146 *chip, | 
|  | 414 | int stream_number, | 
|  | 415 | unsigned char *start_addr, | 
|  | 416 | unsigned int buffer_size) | 
|  | 417 | { | 
|  | 418 | size_t pci_adp = 0; | 
|  | 419 | size_t ptr = 0; | 
|  | 420 | if (stream_number == 0) { | 
|  | 421 | pci_adp = READREG(PCI_ADP2); | 
|  | 422 | ptr = pci_adp - (size_t) start_addr; | 
|  | 423 |  | 
|  | 424 | if (ptr == buffer_size) | 
|  | 425 | ptr = 0; | 
|  | 426 | } | 
|  | 427 | return ptr; | 
|  | 428 | } | 
|  | 429 |  | 
|  | 430 | void snd_aw2_saa7146_use_digital_input(struct snd_aw2_saa7146 *chip, | 
|  | 431 | int use_digital) | 
|  | 432 | { | 
|  | 433 | /* FIXME: switch between analog and digital input does not always work. | 
|  | 434 | It can produce a kind of white noise. It seams that received data | 
|  | 435 | are inverted sometime (endian inversion). Why ? I don't know, maybe | 
|  | 436 | a problem of synchronization... However for the time being I have | 
|  | 437 | not found the problem. Workaround: switch again (and again) between | 
|  | 438 | digital and analog input until it works. */ | 
|  | 439 | if (use_digital) | 
|  | 440 | WRITEREG(0x40, GPIO_CTRL); | 
|  | 441 | else | 
|  | 442 | WRITEREG(0x50, GPIO_CTRL); | 
|  | 443 | } | 
|  | 444 |  | 
|  | 445 | int snd_aw2_saa7146_is_using_digital_input(struct snd_aw2_saa7146 *chip) | 
|  | 446 | { | 
|  | 447 | unsigned int reg_val = READREG(GPIO_CTRL); | 
|  | 448 | if ((reg_val & 0xFF) == 0x40) | 
|  | 449 | return 1; | 
|  | 450 | else | 
|  | 451 | return 0; | 
|  | 452 | } | 
|  | 453 |  | 
|  | 454 |  | 
|  | 455 | static int snd_aw2_saa7146_get_limit(int size) | 
|  | 456 | { | 
|  | 457 | int limitsize = 32; | 
|  | 458 | int limit = 0; | 
|  | 459 | while (limitsize < size) { | 
|  | 460 | limitsize *= 2; | 
|  | 461 | limit++; | 
|  | 462 | } | 
|  | 463 | return limit; | 
|  | 464 | } |