firmware/drivers/tuner/fmclipplus.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Tuner "middleware" for unidentified Silicon Labs chip present in some
  11  * Sansa Clip+ players
  12  *
  13  * Copyright (C) 2010 Bertrik Sikken
  14  * Copyright (C) 2008 Nils Wallménius (si4700 code that this was based on)
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version 2
  19  * of the License, or (at your option) any later version.
  20  *
  21  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  22  * KIND, either express or implied.
  23  *
  24  ****************************************************************************/
  25 #include "config.h"
  26 #include <stdbool.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include "kernel.h"
  30 #include "tuner.h" /* tuner abstraction interface */
  31 #include "fmradio.h"
  32 #include "fmradio_i2c.h" /* physical interface driver */
  33
  34 #define SEEK_THRESHOLD 0x10
  35
  36 #define I2C_ADR 0x20
  37
  38 /** Registers and bits **/
  39 #define POWERCFG    0x2
  40 #define CHANNEL     0x3
  41 #define SYSCONFIG1  0x4
  42 #define SYSCONFIG2  0x5
  43 #define SYSCONFIG3  0x6
  44
  45 #define READCHAN    0xA
  46 #define STATUSRSSI  0xB
  47 #define IDENT       0xC
  48
  49
  50 /* POWERCFG (0x2) */
  51 #define POWERCFG_DMUTE      (0x1 << 14)
  52 #define POWERCFG_MONO       (0x1 << 13)
  53 #define POWERCFG_ENABLE     (0x1 <<  0)
  54
  55 /* CHANNEL (0x3) */
  56 #define CHANNEL_CHAN        (0x3ff << 6)
  57     #define CHANNEL_CHANw(x) (((x) << 6) & CHANNEL_CHAN)
  58 #define CHANNEL_TUNE        (0x1 << 4)
  59 #define CHANNEL_BAND        (0x3 << 2)
  60     #define CHANNEL_BANDw(x)        (((x) << 2) & CHANNEL_BAND)
  61     #define CHANNEL_BANDr(x)        (((x) & CHANNEL_BAND) >> 2)
  62     #define CHANNEL_BAND_875_1080   (0x0 << 2) /* tenth-megahertz */
  63     #define CHANNEL_BAND_760_1080   (0x1 << 2)
  64     #define CHANNEL_BAND_760_900    (0x2 << 2)
  65 #define CHANNEL_SPACE       (0x3 << 0)
  66     #define CHANNEL_SPACEw(x)  (((x) << 0) & CHANNEL_SPACE)
  67     #define CHANNEL_SPACEr(x)  (((x) & CHANNEL_SPACE) >> 0)
  68     #define CHANNEL_SPACE_200KHZ    (0x0 << 0)
  69     #define CHANNEL_SPACE_100KHZ    (0x1 << 0)
  70     #define CHANNEL_SPACE_50KHZ     (0x2 << 0)
  71
  72 /* SYSCONFIG1 (0x4) */
  73 #define SYSCONFIG1_DE       (0x1 << 11)
  74
  75 /* READCHAN (0xA) */
  76 #define READCHAN_READCHAN   (0x3ff << 0)
  77     #define READCHAN_READCHANr(x) (((x) & READCHAN_READCHAN) >> 0)
  78 #define READCHAN_STC        (0x1 << 14)
  79 #define READCHAN_ST         (0x1 << 10)
  80
  81 /* STATUSRSSI (0xB) */
  82 #define STATUSRSSI_RSSI     (0x3F << 10)
  83     #define STATUSRSSI_RSSIr(x) (((x) & STATUSRSSI_RSSI) >> 10)
  84 #define STATUSRSSI_AFCRL    (0x1 << 8)
  85
  86 static const uint16_t initvals[32] = {
  87     0x8110, 0x4580, 0xC401, 0x1B90,
  88     0x0400, 0x866F, 0x8000, 0x4712,
  89     0x5EC6, 0x0000, 0x406E, 0x2D80,
  90     0x5803, 0x5804, 0x5804, 0x5804,
  91
  92     0x0047, 0x9000, 0xF587, 0x0009,
  93     0x00F1, 0x41C0, 0x41E0, 0x506F,
  94     0x5592, 0x007D, 0x10A0, 0x0780,
  95     0x311D, 0x4006, 0x1F9B, 0x4C2B
  96 };
  97
  98 static bool tuner_present = false;
  99 static int curr_frequency = 87500000; /* Current station frequency (HZ) */
 100 static uint16_t cache[32];
 101
 102 /* reads <len> registers from radio at offset 0x0A into cache */
 103 static void fmclipplus_read(int len)
 104 {
 105     int i;
 106     unsigned char buf[64];
 107     unsigned char *ptr = buf;
 108     uint16_t data;
 109
 110     fmradio_i2c_read(I2C_ADR, buf, len * 2);
 111     for (i = 0; i < len; i++) {
 112         data = ptr[0] << 8 | ptr[1];
 113         cache[(i + READCHAN) & 0x1F] = data;
 114         ptr += 2;
 115     }
 116 }
 117
 118 /* writes <len> registers from cache to radio at offset 0x02 */
 119 static void fmclipplus_write(int len)
 120 {
 121     int i;
 122     unsigned char buf[64];
 123     unsigned char *ptr = buf;
 124     uint16_t data;
 125
 126     for (i = 0; i < len; i++) {
 127         data = cache[(i + POWERCFG) & 0x1F];
 128         *ptr++ = (data >> 8) & 0xFF;
 129         *ptr++ = data & 0xFF;
 130     }
 131     fmradio_i2c_write(I2C_ADR, buf, len * 2);
 132 }
 133
 134 static uint16_t fmclipplus_read_reg(int reg)
 135 {
 136     fmclipplus_read(((reg - READCHAN) & 0x1F) + 1);
 137     return cache[reg];
 138 }
 139
 140 static void fmclipplus_write_reg(int reg, uint16_t value)
 141 {
 142     cache[reg] = value;
 143 }
 144
 145 static void fmclipplus_write_cache(void)
 146 {
 147     fmclipplus_write(5);
 148 }
 149
 150 static void fmclipplus_write_masked(int reg, uint16_t bits, uint16_t mask)
 151 {
 152     fmclipplus_write_reg(reg, (cache[reg] & ~mask) | (bits & mask));
 153 }
 154
 155 static void fmclipplus_write_clear(int reg, uint16_t mask)
 156 {
 157     fmclipplus_write_reg(reg, cache[reg] & ~mask);
 158 }
 159
 160 static void fmclipplus_sleep(int snooze)
 161 {
 162     if (snooze) {
 163         fmclipplus_write_masked(POWERCFG, 0, 0xFF);
 164     }
 165     else {
 166         fmclipplus_write_masked(POWERCFG, 1, 0xFF);
 167     }
 168     fmclipplus_write_cache();
 169 }
 170
 171 bool fmclipplus_detect(void)
 172 {
 173     return ((fmclipplus_read_reg(IDENT) & 0xFF00) == 0x5800);
 174  }
 175
 176 void fmclipplus_init(void)
 177 {
 178     if (fmclipplus_detect()) {
 179         tuner_present = true;
 180
 181         // send pre-initialisation value
 182         fmclipplus_write_reg(POWERCFG, 0x200);
 183         fmclipplus_write(2);
 184         sleep(HZ * 10 / 100);
 185
 186         // write initialisation values
 187         memcpy(cache, initvals, sizeof(cache));
 188         fmclipplus_write(32);
 189         sleep(HZ * 70 / 1000);
 190     }
 191 }
 192
 193 static void fmclipplus_set_frequency(int freq)
 194 {
 195     int i;
 196
 197     /* check BAND and spacings */
 198     fmclipplus_read_reg(STATUSRSSI);
 199     int start = CHANNEL_BANDr(cache[CHANNEL]) & 1 ? 76000000 : 87000000;
 200     int chan = (freq - start) / 50000;
 201
 202     curr_frequency = freq;
 203
 204     for (i = 0; i < 5; i++) {
 205         /* tune and wait a bit */
 206         fmclipplus_write_masked(CHANNEL, CHANNEL_CHANw(chan) | CHANNEL_TUNE,
 207                                 CHANNEL_CHAN | CHANNEL_TUNE);
 208         fmclipplus_write_cache();
 209         sleep(HZ * 70 / 1000);
 210         fmclipplus_write_clear(CHANNEL, CHANNEL_TUNE);
 211         fmclipplus_write_cache();
 212
 213         /* check if tuning was successful */
 214         fmclipplus_read_reg(STATUSRSSI);
 215         if (cache[READCHAN] & READCHAN_STC) {
 216             if (READCHAN_READCHANr(cache[READCHAN]) == chan) {
 217                 break;
 218             }
 219         }
 220     }
 221 }
 222
 223 static int fmclipplus_tuned(void)
 224 {
 225     /* Primitive tuning check: sufficient level and AFC not railed */
 226     uint16_t status = fmclipplus_read_reg(STATUSRSSI);
 227     if (STATUSRSSI_RSSIr(status) >= SEEK_THRESHOLD &&
 228         (status & STATUSRSSI_AFCRL) == 0) {
 229         return 1;
 230     }
 231
 232     return 0;
 233 }
 234
 235 static void fmclipplus_set_region(int region)
 236 {
 237     const struct fmclipplus_region_data *rd = &fmclipplus_region_data[region];
 238     uint16_t bandspacing = CHANNEL_BANDw(rd->band) |
 239                            CHANNEL_SPACEw(CHANNEL_SPACE_50KHZ);
 240     uint16_t oldbs = cache[CHANNEL] & (CHANNEL_BAND | CHANNEL_SPACE);
 241
 242     fmclipplus_write_masked(SYSCONFIG1, rd->deemphasis ? SYSCONFIG1_DE : 0,
 243                         SYSCONFIG1_DE);
 244     fmclipplus_write_masked(CHANNEL, bandspacing, CHANNEL_BAND | CHANNEL_SPACE);
 245     fmclipplus_write_cache();
 246
 247     /* Retune if this region change would change the channel number. */
 248     if (oldbs != bandspacing) {
 249         fmclipplus_set_frequency(curr_frequency);
 250     }
 251 }
 252
 253 static bool fmclipplus_st(void)
 254 {
 255     return (fmclipplus_read_reg(READCHAN) & READCHAN_ST);
 256 }
 257
 258 /* tuner abstraction layer: set something to the tuner */
 259 int fmclipplus_set(int setting, int value)
 260 {
 261     switch (setting) {
 262     case RADIO_SLEEP:
 263         if (value != 2) {
 264             fmclipplus_sleep(value);
 265         }
 266         break;
 267
 268     case RADIO_FREQUENCY:
 269         fmclipplus_set_frequency(value);
 270         break;
 271
 272     case RADIO_SCAN_FREQUENCY:
 273         fmclipplus_set_frequency(value);
 274         return fmclipplus_tuned();
 275
 276     case RADIO_MUTE:
 277         fmclipplus_write_masked(POWERCFG, value ? 0 : POWERCFG_DMUTE,
 278                                 POWERCFG_DMUTE);
 279         fmclipplus_write_masked(SYSCONFIG1, (3 << 9), (3 << 9));
 280         fmclipplus_write_masked(SYSCONFIG2, (0xF << 0), (0xF << 0));
 281         fmclipplus_write_cache();
 282         break;
 283
 284     case RADIO_REGION:
 285         fmclipplus_set_region(value);
 286         break;
 287
 288     case RADIO_FORCE_MONO:
 289         fmclipplus_write_masked(POWERCFG, value ? POWERCFG_MONO : 0,
 290                             POWERCFG_MONO);
 291         fmclipplus_write_cache();
 292         break;
 293
 294     default:
 295         return -1;
 296     }
 297
 298     return 1;
 299 }
 300
 301 /* tuner abstraction layer: read something from the tuner */
 302 int fmclipplus_get(int setting)
 303 {
 304     int val = -1; /* default for unsupported query */
 305
 306     switch (setting) {
 307     case RADIO_PRESENT:
 308         val = tuner_present ? 1 : 0;
 309         break;
 310
 311     case RADIO_TUNED:
 312         val = fmclipplus_tuned();
 313         break;
 314
 315     case RADIO_STEREO:
 316         val = fmclipplus_st();
 317         break;
 318     }
 319
 320     return val;
 321 }
 322
 323 void fmclipplus_dbg_info(struct fmclipplus_dbg_info *nfo)
 324 {
 325     fmclipplus_read(32);
 326     memcpy(nfo->regs, cache, sizeof (nfo->regs));
 327 }
 328