io.c 15 KB

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  1. /*
  2. * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
  3. * Creative Labs, Inc.
  4. * Routines for control of EMU10K1 chips
  5. *
  6. * BUGS:
  7. * --
  8. *
  9. * TODO:
  10. * --
  11. *
  12. * This program is free software; you can redistribute it and/or modify
  13. * it under the terms of the GNU General Public License as published by
  14. * the Free Software Foundation; either version 2 of the License, or
  15. * (at your option) any later version.
  16. *
  17. * This program is distributed in the hope that it will be useful,
  18. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20. * GNU General Public License for more details.
  21. *
  22. * You should have received a copy of the GNU General Public License
  23. * along with this program; if not, write to the Free Software
  24. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  25. *
  26. */
  27. #include <sound/driver.h>
  28. #include <linux/time.h>
  29. #include <sound/core.h>
  30. #include <sound/emu10k1.h>
  31. #include <linux/delay.h>
  32. #include "p17v.h"
  33. unsigned int snd_emu10k1_ptr_read(struct snd_emu10k1 * emu, unsigned int reg, unsigned int chn)
  34. {
  35. unsigned long flags;
  36. unsigned int regptr, val;
  37. unsigned int mask;
  38. mask = emu->audigy ? A_PTR_ADDRESS_MASK : PTR_ADDRESS_MASK;
  39. regptr = ((reg << 16) & mask) | (chn & PTR_CHANNELNUM_MASK);
  40. if (reg & 0xff000000) {
  41. unsigned char size, offset;
  42. size = (reg >> 24) & 0x3f;
  43. offset = (reg >> 16) & 0x1f;
  44. mask = ((1 << size) - 1) << offset;
  45. spin_lock_irqsave(&emu->emu_lock, flags);
  46. outl(regptr, emu->port + PTR);
  47. val = inl(emu->port + DATA);
  48. spin_unlock_irqrestore(&emu->emu_lock, flags);
  49. return (val & mask) >> offset;
  50. } else {
  51. spin_lock_irqsave(&emu->emu_lock, flags);
  52. outl(regptr, emu->port + PTR);
  53. val = inl(emu->port + DATA);
  54. spin_unlock_irqrestore(&emu->emu_lock, flags);
  55. return val;
  56. }
  57. }
  58. EXPORT_SYMBOL(snd_emu10k1_ptr_read);
  59. void snd_emu10k1_ptr_write(struct snd_emu10k1 *emu, unsigned int reg, unsigned int chn, unsigned int data)
  60. {
  61. unsigned int regptr;
  62. unsigned long flags;
  63. unsigned int mask;
  64. mask = emu->audigy ? A_PTR_ADDRESS_MASK : PTR_ADDRESS_MASK;
  65. regptr = ((reg << 16) & mask) | (chn & PTR_CHANNELNUM_MASK);
  66. if (reg & 0xff000000) {
  67. unsigned char size, offset;
  68. size = (reg >> 24) & 0x3f;
  69. offset = (reg >> 16) & 0x1f;
  70. mask = ((1 << size) - 1) << offset;
  71. data = (data << offset) & mask;
  72. spin_lock_irqsave(&emu->emu_lock, flags);
  73. outl(regptr, emu->port + PTR);
  74. data |= inl(emu->port + DATA) & ~mask;
  75. outl(data, emu->port + DATA);
  76. spin_unlock_irqrestore(&emu->emu_lock, flags);
  77. } else {
  78. spin_lock_irqsave(&emu->emu_lock, flags);
  79. outl(regptr, emu->port + PTR);
  80. outl(data, emu->port + DATA);
  81. spin_unlock_irqrestore(&emu->emu_lock, flags);
  82. }
  83. }
  84. EXPORT_SYMBOL(snd_emu10k1_ptr_write);
  85. unsigned int snd_emu10k1_ptr20_read(struct snd_emu10k1 * emu,
  86. unsigned int reg,
  87. unsigned int chn)
  88. {
  89. unsigned long flags;
  90. unsigned int regptr, val;
  91. regptr = (reg << 16) | chn;
  92. spin_lock_irqsave(&emu->emu_lock, flags);
  93. outl(regptr, emu->port + 0x20 + PTR);
  94. val = inl(emu->port + 0x20 + DATA);
  95. spin_unlock_irqrestore(&emu->emu_lock, flags);
  96. return val;
  97. }
  98. void snd_emu10k1_ptr20_write(struct snd_emu10k1 *emu,
  99. unsigned int reg,
  100. unsigned int chn,
  101. unsigned int data)
  102. {
  103. unsigned int regptr;
  104. unsigned long flags;
  105. regptr = (reg << 16) | chn;
  106. spin_lock_irqsave(&emu->emu_lock, flags);
  107. outl(regptr, emu->port + 0x20 + PTR);
  108. outl(data, emu->port + 0x20 + DATA);
  109. spin_unlock_irqrestore(&emu->emu_lock, flags);
  110. }
  111. int snd_emu10k1_spi_write(struct snd_emu10k1 * emu,
  112. unsigned int data)
  113. {
  114. unsigned int reset, set;
  115. unsigned int reg, tmp;
  116. int n, result;
  117. if (emu->card_capabilities->ca0108_chip)
  118. reg = 0x3c; /* PTR20, reg 0x3c */
  119. else {
  120. /* For other chip types the SPI register
  121. * is currently unknown. */
  122. return 1;
  123. }
  124. if (data > 0xffff) /* Only 16bit values allowed */
  125. return 1;
  126. tmp = snd_emu10k1_ptr20_read(emu, reg, 0);
  127. reset = (tmp & ~0x3ffff) | 0x20000; /* Set xxx20000 */
  128. set = reset | 0x10000; /* Set xxx1xxxx */
  129. snd_emu10k1_ptr20_write(emu, reg, 0, reset | data);
  130. tmp = snd_emu10k1_ptr20_read(emu, reg, 0); /* write post */
  131. snd_emu10k1_ptr20_write(emu, reg, 0, set | data);
  132. result = 1;
  133. /* Wait for status bit to return to 0 */
  134. for (n = 0; n < 100; n++) {
  135. udelay(10);
  136. tmp = snd_emu10k1_ptr20_read(emu, reg, 0);
  137. if (!(tmp & 0x10000)) {
  138. result = 0;
  139. break;
  140. }
  141. }
  142. if (result) /* Timed out */
  143. return 1;
  144. snd_emu10k1_ptr20_write(emu, reg, 0, reset | data);
  145. tmp = snd_emu10k1_ptr20_read(emu, reg, 0); /* Write post */
  146. return 0;
  147. }
  148. /* The ADC does not support i2c read, so only write is implemented */
  149. int snd_emu10k1_i2c_write(struct snd_emu10k1 *emu,
  150. u32 reg,
  151. u32 value)
  152. {
  153. u32 tmp;
  154. int timeout = 0;
  155. int status;
  156. int retry;
  157. if ((reg > 0x7f) || (value > 0x1ff)) {
  158. snd_printk(KERN_ERR "i2c_write: invalid values.\n");
  159. return -EINVAL;
  160. }
  161. tmp = reg << 25 | value << 16;
  162. // snd_printk("I2C-write:reg=0x%x, value=0x%x\n", reg, value);
  163. /* Not sure what this I2C channel controls. */
  164. /* snd_emu10k1_ptr_write(emu, P17V_I2C_0, 0, tmp); */
  165. /* This controls the I2C connected to the WM8775 ADC Codec */
  166. snd_emu10k1_ptr20_write(emu, P17V_I2C_1, 0, tmp);
  167. tmp = snd_emu10k1_ptr20_read(emu, P17V_I2C_1, 0); /* write post */
  168. for (retry = 0; retry < 10; retry++) {
  169. /* Send the data to i2c */
  170. //tmp = snd_emu10k1_ptr_read(emu, P17V_I2C_ADDR, 0);
  171. //tmp = tmp & ~(I2C_A_ADC_READ|I2C_A_ADC_LAST|I2C_A_ADC_START|I2C_A_ADC_ADD_MASK);
  172. tmp = 0;
  173. tmp = tmp | (I2C_A_ADC_LAST|I2C_A_ADC_START|I2C_A_ADC_ADD);
  174. snd_emu10k1_ptr20_write(emu, P17V_I2C_ADDR, 0, tmp);
  175. /* Wait till the transaction ends */
  176. while (1) {
  177. udelay(10);
  178. status = snd_emu10k1_ptr20_read(emu, P17V_I2C_ADDR, 0);
  179. // snd_printk("I2C:status=0x%x\n", status);
  180. timeout++;
  181. if ((status & I2C_A_ADC_START) == 0)
  182. break;
  183. if (timeout > 1000) {
  184. snd_printk("emu10k1:I2C:timeout status=0x%x\n", status);
  185. break;
  186. }
  187. }
  188. //Read back and see if the transaction is successful
  189. if ((status & I2C_A_ADC_ABORT) == 0)
  190. break;
  191. }
  192. if (retry == 10) {
  193. snd_printk(KERN_ERR "Writing to ADC failed!\n");
  194. return -EINVAL;
  195. }
  196. return 0;
  197. }
  198. int snd_emu1010_fpga_write(struct snd_emu10k1 * emu, u32 reg, u32 value)
  199. {
  200. if (reg > 0x3f)
  201. return 1;
  202. reg += 0x40; /* 0x40 upwards are registers. */
  203. if (value < 0 || value > 0x3f) /* 0 to 0x3f are values */
  204. return 1;
  205. outl(reg, emu->port + A_IOCFG);
  206. udelay(10);
  207. outl(reg | 0x80, emu->port + A_IOCFG); /* High bit clocks the value into the fpga. */
  208. udelay(10);
  209. outl(value, emu->port + A_IOCFG);
  210. udelay(10);
  211. outl(value | 0x80 , emu->port + A_IOCFG); /* High bit clocks the value into the fpga. */
  212. return 0;
  213. }
  214. int snd_emu1010_fpga_read(struct snd_emu10k1 * emu, u32 reg, u32 *value)
  215. {
  216. if (reg > 0x3f)
  217. return 1;
  218. reg += 0x40; /* 0x40 upwards are registers. */
  219. outl(reg, emu->port + A_IOCFG);
  220. udelay(10);
  221. outl(reg | 0x80, emu->port + A_IOCFG); /* High bit clocks the value into the fpga. */
  222. udelay(10);
  223. *value = ((inl(emu->port + A_IOCFG) >> 8) & 0x7f);
  224. return 0;
  225. }
  226. /* Each Destination has one and only one Source,
  227. * but one Source can feed any number of Destinations simultaneously.
  228. */
  229. int snd_emu1010_fpga_link_dst_src_write(struct snd_emu10k1 * emu, u32 dst, u32 src)
  230. {
  231. snd_emu1010_fpga_write(emu, 0x00, ((dst >> 8) & 0x3f) );
  232. snd_emu1010_fpga_write(emu, 0x01, (dst & 0x3f) );
  233. snd_emu1010_fpga_write(emu, 0x02, ((src >> 8) & 0x3f) );
  234. snd_emu1010_fpga_write(emu, 0x03, (src & 0x3f) );
  235. return 0;
  236. }
  237. void snd_emu10k1_intr_enable(struct snd_emu10k1 *emu, unsigned int intrenb)
  238. {
  239. unsigned long flags;
  240. unsigned int enable;
  241. spin_lock_irqsave(&emu->emu_lock, flags);
  242. enable = inl(emu->port + INTE) | intrenb;
  243. outl(enable, emu->port + INTE);
  244. spin_unlock_irqrestore(&emu->emu_lock, flags);
  245. }
  246. void snd_emu10k1_intr_disable(struct snd_emu10k1 *emu, unsigned int intrenb)
  247. {
  248. unsigned long flags;
  249. unsigned int enable;
  250. spin_lock_irqsave(&emu->emu_lock, flags);
  251. enable = inl(emu->port + INTE) & ~intrenb;
  252. outl(enable, emu->port + INTE);
  253. spin_unlock_irqrestore(&emu->emu_lock, flags);
  254. }
  255. void snd_emu10k1_voice_intr_enable(struct snd_emu10k1 *emu, unsigned int voicenum)
  256. {
  257. unsigned long flags;
  258. unsigned int val;
  259. spin_lock_irqsave(&emu->emu_lock, flags);
  260. /* voice interrupt */
  261. if (voicenum >= 32) {
  262. outl(CLIEH << 16, emu->port + PTR);
  263. val = inl(emu->port + DATA);
  264. val |= 1 << (voicenum - 32);
  265. } else {
  266. outl(CLIEL << 16, emu->port + PTR);
  267. val = inl(emu->port + DATA);
  268. val |= 1 << voicenum;
  269. }
  270. outl(val, emu->port + DATA);
  271. spin_unlock_irqrestore(&emu->emu_lock, flags);
  272. }
  273. void snd_emu10k1_voice_intr_disable(struct snd_emu10k1 *emu, unsigned int voicenum)
  274. {
  275. unsigned long flags;
  276. unsigned int val;
  277. spin_lock_irqsave(&emu->emu_lock, flags);
  278. /* voice interrupt */
  279. if (voicenum >= 32) {
  280. outl(CLIEH << 16, emu->port + PTR);
  281. val = inl(emu->port + DATA);
  282. val &= ~(1 << (voicenum - 32));
  283. } else {
  284. outl(CLIEL << 16, emu->port + PTR);
  285. val = inl(emu->port + DATA);
  286. val &= ~(1 << voicenum);
  287. }
  288. outl(val, emu->port + DATA);
  289. spin_unlock_irqrestore(&emu->emu_lock, flags);
  290. }
  291. void snd_emu10k1_voice_intr_ack(struct snd_emu10k1 *emu, unsigned int voicenum)
  292. {
  293. unsigned long flags;
  294. spin_lock_irqsave(&emu->emu_lock, flags);
  295. /* voice interrupt */
  296. if (voicenum >= 32) {
  297. outl(CLIPH << 16, emu->port + PTR);
  298. voicenum = 1 << (voicenum - 32);
  299. } else {
  300. outl(CLIPL << 16, emu->port + PTR);
  301. voicenum = 1 << voicenum;
  302. }
  303. outl(voicenum, emu->port + DATA);
  304. spin_unlock_irqrestore(&emu->emu_lock, flags);
  305. }
  306. void snd_emu10k1_voice_half_loop_intr_enable(struct snd_emu10k1 *emu, unsigned int voicenum)
  307. {
  308. unsigned long flags;
  309. unsigned int val;
  310. spin_lock_irqsave(&emu->emu_lock, flags);
  311. /* voice interrupt */
  312. if (voicenum >= 32) {
  313. outl(HLIEH << 16, emu->port + PTR);
  314. val = inl(emu->port + DATA);
  315. val |= 1 << (voicenum - 32);
  316. } else {
  317. outl(HLIEL << 16, emu->port + PTR);
  318. val = inl(emu->port + DATA);
  319. val |= 1 << voicenum;
  320. }
  321. outl(val, emu->port + DATA);
  322. spin_unlock_irqrestore(&emu->emu_lock, flags);
  323. }
  324. void snd_emu10k1_voice_half_loop_intr_disable(struct snd_emu10k1 *emu, unsigned int voicenum)
  325. {
  326. unsigned long flags;
  327. unsigned int val;
  328. spin_lock_irqsave(&emu->emu_lock, flags);
  329. /* voice interrupt */
  330. if (voicenum >= 32) {
  331. outl(HLIEH << 16, emu->port + PTR);
  332. val = inl(emu->port + DATA);
  333. val &= ~(1 << (voicenum - 32));
  334. } else {
  335. outl(HLIEL << 16, emu->port + PTR);
  336. val = inl(emu->port + DATA);
  337. val &= ~(1 << voicenum);
  338. }
  339. outl(val, emu->port + DATA);
  340. spin_unlock_irqrestore(&emu->emu_lock, flags);
  341. }
  342. void snd_emu10k1_voice_half_loop_intr_ack(struct snd_emu10k1 *emu, unsigned int voicenum)
  343. {
  344. unsigned long flags;
  345. spin_lock_irqsave(&emu->emu_lock, flags);
  346. /* voice interrupt */
  347. if (voicenum >= 32) {
  348. outl(HLIPH << 16, emu->port + PTR);
  349. voicenum = 1 << (voicenum - 32);
  350. } else {
  351. outl(HLIPL << 16, emu->port + PTR);
  352. voicenum = 1 << voicenum;
  353. }
  354. outl(voicenum, emu->port + DATA);
  355. spin_unlock_irqrestore(&emu->emu_lock, flags);
  356. }
  357. void snd_emu10k1_voice_set_loop_stop(struct snd_emu10k1 *emu, unsigned int voicenum)
  358. {
  359. unsigned long flags;
  360. unsigned int sol;
  361. spin_lock_irqsave(&emu->emu_lock, flags);
  362. /* voice interrupt */
  363. if (voicenum >= 32) {
  364. outl(SOLEH << 16, emu->port + PTR);
  365. sol = inl(emu->port + DATA);
  366. sol |= 1 << (voicenum - 32);
  367. } else {
  368. outl(SOLEL << 16, emu->port + PTR);
  369. sol = inl(emu->port + DATA);
  370. sol |= 1 << voicenum;
  371. }
  372. outl(sol, emu->port + DATA);
  373. spin_unlock_irqrestore(&emu->emu_lock, flags);
  374. }
  375. void snd_emu10k1_voice_clear_loop_stop(struct snd_emu10k1 *emu, unsigned int voicenum)
  376. {
  377. unsigned long flags;
  378. unsigned int sol;
  379. spin_lock_irqsave(&emu->emu_lock, flags);
  380. /* voice interrupt */
  381. if (voicenum >= 32) {
  382. outl(SOLEH << 16, emu->port + PTR);
  383. sol = inl(emu->port + DATA);
  384. sol &= ~(1 << (voicenum - 32));
  385. } else {
  386. outl(SOLEL << 16, emu->port + PTR);
  387. sol = inl(emu->port + DATA);
  388. sol &= ~(1 << voicenum);
  389. }
  390. outl(sol, emu->port + DATA);
  391. spin_unlock_irqrestore(&emu->emu_lock, flags);
  392. }
  393. void snd_emu10k1_wait(struct snd_emu10k1 *emu, unsigned int wait)
  394. {
  395. volatile unsigned count;
  396. unsigned int newtime = 0, curtime;
  397. curtime = inl(emu->port + WC) >> 6;
  398. while (wait-- > 0) {
  399. count = 0;
  400. while (count++ < 16384) {
  401. newtime = inl(emu->port + WC) >> 6;
  402. if (newtime != curtime)
  403. break;
  404. }
  405. if (count >= 16384)
  406. break;
  407. curtime = newtime;
  408. }
  409. }
  410. unsigned short snd_emu10k1_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
  411. {
  412. struct snd_emu10k1 *emu = ac97->private_data;
  413. unsigned long flags;
  414. unsigned short val;
  415. spin_lock_irqsave(&emu->emu_lock, flags);
  416. outb(reg, emu->port + AC97ADDRESS);
  417. val = inw(emu->port + AC97DATA);
  418. spin_unlock_irqrestore(&emu->emu_lock, flags);
  419. return val;
  420. }
  421. void snd_emu10k1_ac97_write(struct snd_ac97 *ac97, unsigned short reg, unsigned short data)
  422. {
  423. struct snd_emu10k1 *emu = ac97->private_data;
  424. unsigned long flags;
  425. spin_lock_irqsave(&emu->emu_lock, flags);
  426. outb(reg, emu->port + AC97ADDRESS);
  427. outw(data, emu->port + AC97DATA);
  428. spin_unlock_irqrestore(&emu->emu_lock, flags);
  429. }
  430. /*
  431. * convert rate to pitch
  432. */
  433. unsigned int snd_emu10k1_rate_to_pitch(unsigned int rate)
  434. {
  435. static u32 logMagTable[128] = {
  436. 0x00000, 0x02dfc, 0x05b9e, 0x088e6, 0x0b5d6, 0x0e26f, 0x10eb3, 0x13aa2,
  437. 0x1663f, 0x1918a, 0x1bc84, 0x1e72e, 0x2118b, 0x23b9a, 0x2655d, 0x28ed5,
  438. 0x2b803, 0x2e0e8, 0x30985, 0x331db, 0x359eb, 0x381b6, 0x3a93d, 0x3d081,
  439. 0x3f782, 0x41e42, 0x444c1, 0x46b01, 0x49101, 0x4b6c4, 0x4dc49, 0x50191,
  440. 0x5269e, 0x54b6f, 0x57006, 0x59463, 0x5b888, 0x5dc74, 0x60029, 0x623a7,
  441. 0x646ee, 0x66a00, 0x68cdd, 0x6af86, 0x6d1fa, 0x6f43c, 0x7164b, 0x73829,
  442. 0x759d4, 0x77b4f, 0x79c9a, 0x7bdb5, 0x7dea1, 0x7ff5e, 0x81fed, 0x8404e,
  443. 0x86082, 0x88089, 0x8a064, 0x8c014, 0x8df98, 0x8fef1, 0x91e20, 0x93d26,
  444. 0x95c01, 0x97ab4, 0x9993e, 0x9b79f, 0x9d5d9, 0x9f3ec, 0xa11d8, 0xa2f9d,
  445. 0xa4d3c, 0xa6ab5, 0xa8808, 0xaa537, 0xac241, 0xadf26, 0xafbe7, 0xb1885,
  446. 0xb3500, 0xb5157, 0xb6d8c, 0xb899f, 0xba58f, 0xbc15e, 0xbdd0c, 0xbf899,
  447. 0xc1404, 0xc2f50, 0xc4a7b, 0xc6587, 0xc8073, 0xc9b3f, 0xcb5ed, 0xcd07c,
  448. 0xceaec, 0xd053f, 0xd1f73, 0xd398a, 0xd5384, 0xd6d60, 0xd8720, 0xda0c3,
  449. 0xdba4a, 0xdd3b4, 0xded03, 0xe0636, 0xe1f4e, 0xe384a, 0xe512c, 0xe69f3,
  450. 0xe829f, 0xe9b31, 0xeb3a9, 0xecc08, 0xee44c, 0xefc78, 0xf148a, 0xf2c83,
  451. 0xf4463, 0xf5c2a, 0xf73da, 0xf8b71, 0xfa2f0, 0xfba57, 0xfd1a7, 0xfe8df
  452. };
  453. static char logSlopeTable[128] = {
  454. 0x5c, 0x5c, 0x5b, 0x5a, 0x5a, 0x59, 0x58, 0x58,
  455. 0x57, 0x56, 0x56, 0x55, 0x55, 0x54, 0x53, 0x53,
  456. 0x52, 0x52, 0x51, 0x51, 0x50, 0x50, 0x4f, 0x4f,
  457. 0x4e, 0x4d, 0x4d, 0x4d, 0x4c, 0x4c, 0x4b, 0x4b,
  458. 0x4a, 0x4a, 0x49, 0x49, 0x48, 0x48, 0x47, 0x47,
  459. 0x47, 0x46, 0x46, 0x45, 0x45, 0x45, 0x44, 0x44,
  460. 0x43, 0x43, 0x43, 0x42, 0x42, 0x42, 0x41, 0x41,
  461. 0x41, 0x40, 0x40, 0x40, 0x3f, 0x3f, 0x3f, 0x3e,
  462. 0x3e, 0x3e, 0x3d, 0x3d, 0x3d, 0x3c, 0x3c, 0x3c,
  463. 0x3b, 0x3b, 0x3b, 0x3b, 0x3a, 0x3a, 0x3a, 0x39,
  464. 0x39, 0x39, 0x39, 0x38, 0x38, 0x38, 0x38, 0x37,
  465. 0x37, 0x37, 0x37, 0x36, 0x36, 0x36, 0x36, 0x35,
  466. 0x35, 0x35, 0x35, 0x34, 0x34, 0x34, 0x34, 0x34,
  467. 0x33, 0x33, 0x33, 0x33, 0x32, 0x32, 0x32, 0x32,
  468. 0x32, 0x31, 0x31, 0x31, 0x31, 0x31, 0x30, 0x30,
  469. 0x30, 0x30, 0x30, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f
  470. };
  471. int i;
  472. if (rate == 0)
  473. return 0; /* Bail out if no leading "1" */
  474. rate *= 11185; /* Scale 48000 to 0x20002380 */
  475. for (i = 31; i > 0; i--) {
  476. if (rate & 0x80000000) { /* Detect leading "1" */
  477. return (((unsigned int) (i - 15) << 20) +
  478. logMagTable[0x7f & (rate >> 24)] +
  479. (0x7f & (rate >> 17)) *
  480. logSlopeTable[0x7f & (rate >> 24)]);
  481. }
  482. rate <<= 1;
  483. }
  484. return 0; /* Should never reach this point */
  485. }