Make si4700 tuner driver more sane with bit and field defines and entirely hide strange i2c interface from code with write/set/clear/masked functionality. On Gigabeat S use by-the-book busmode selection and GPIO lines. Implement some primitive station detection, debug registers in screen, and misc. changes to tie things together.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19600 a1c6a512-1295-4272-9138-f99709370657

9 files changed, 513 insertions, 176 deletions

diff --git a/apps/debug_menu.c b/apps/debug_menu.c
index f390cced85..9be36df046 100644
--- a/apps/debug_menu.c
+++ b/apps/debug_menu.c
@@ -2293,12 +2293,12 @@ static int radio_callback(int btn, struct gui_synclist *lists)
                         "if_set: %d Hz", lv24020lp_get(LV24020LP_IF_SET) );
     simplelist_addline(SIMPLELIST_ADD_LINE,
                         "sd_set: %d Hz", lv24020lp_get(LV24020LP_SD_SET) );
-#endif
+#endif /* LV24020LP */
 #if (CONFIG_TUNER & S1A0903X01)
     simplelist_addline(SIMPLELIST_ADD_LINE,
                         "Samsung regs: %08X", s1a0903x01_get(RADIO_ALL));
     /* This one doesn't return dynamic data atm */
-#endif
+#endif /* S1A0903X01 */
 #if (CONFIG_TUNER & TEA5767)
     struct tea5767_dbg_info nfo;
     tea5767_dbg_info(&nfo);
@@ -2313,7 +2313,29 @@ static int radio_callback(int btn, struct gui_synclist *lists)
              (unsigned)nfo.write_regs[0], (unsigned)nfo.write_regs[1],
              (unsigned)nfo.write_regs[2], (unsigned)nfo.write_regs[3],
              (unsigned)nfo.write_regs[4]);
-#endif
+#endif /* TEA5767 */
+#if (CONFIG_TUNER & SI4700)
+    struct si4700_dbg_info nfo;
+    si4700_dbg_info(&nfo);
+    simplelist_addline(SIMPLELIST_ADD_LINE, "SI4700 regs:");
+    /* Registers */
+    simplelist_addline(SIMPLELIST_ADD_LINE,
+             "   %04X %04X %04X %04X",
+             (unsigned)nfo.regs[0], (unsigned)nfo.regs[1],
+             (unsigned)nfo.regs[2], (unsigned)nfo.regs[3]);
+    simplelist_addline(SIMPLELIST_ADD_LINE,
+             "   %04X %04X %04X %04X",
+             (unsigned)nfo.regs[4], (unsigned)nfo.regs[5],
+             (unsigned)nfo.regs[6], (unsigned)nfo.regs[7]);
+    simplelist_addline(SIMPLELIST_ADD_LINE,
+             "   %04X %04X %04X %04X",
+             (unsigned)nfo.regs[8], (unsigned)nfo.regs[9],
+             (unsigned)nfo.regs[10], (unsigned)nfo.regs[11]);
+    simplelist_addline(SIMPLELIST_ADD_LINE,
+             "   %04X %04X %04X %04X",
+             (unsigned)nfo.regs[12], (unsigned)nfo.regs[13],
+             (unsigned)nfo.regs[14], (unsigned)nfo.regs[15]);
+#endif /* SI4700 */
     return ACTION_REDRAW;
 }
 static bool dbg_fm_radio(void)
diff --git a/firmware/drivers/tuner/si4700.c b/firmware/drivers/tuner/si4700.c
index f68ea5a750..fb8fc49749 100644
--- a/firmware/drivers/tuner/si4700.c
+++ b/firmware/drivers/tuner/si4700.c
@@ -25,12 +25,33 @@
 #include <string.h>
 #include <stdlib.h>
 #include "kernel.h"
+#include "power.h"
 #include "tuner.h" /* tuner abstraction interface */
 #include "fmradio.h"
 #include "fmradio_i2c.h" /* physical interface driver */
 
+/* some models use the internal 32 kHz oscillator which needs special attention
+   during initialisation, power-up and power-down.
+*/
+#if defined(SANSA_CLIP) || defined(SANSA_E200V2) || defined(SANSA_FUZE)
+#define USE_INTERNAL_OSCILLATOR
+#elif defined(TOSHIBA_GIGABEAT_S)
+#define SI4700_GPIO_SETUP (SYSCONFIG1_GPIO1_HI_Z | \
+                           SYSCONFIG1_GPIO2_HI_Z | \
+                           SYSCONFIG1_GPIO3_MO_ST_I)
+extern int si4700_st(void);
+#endif
+
+#ifndef SI4700_GPIO_SETUP
+#define SI4700_GPIO_SETUP 0
+#endif
+
+#define SEEK_THRESHOLD 0x16
+#define TUNER_VOLUME   0xC
+
 #define I2C_ADR 0x20
 
+/** Registers and bits - "x" denotes Si4702/03 only (so they say) **/
 #define DEVICEID    0x0
 #define CHIPID      0x1
 #define POWERCFG    0x2
@@ -43,20 +64,154 @@
 #define BOOTCONFIG  0x9
 #define STATUSRSSI  0xA
 #define READCHAN    0xB
-#define RDSA        0xC
-#define RDSB        0xD
-#define RDSC        0xE
-#define RDSD        0xF
-
-/* some models use the internal 32 kHz oscillator which needs special attention
-   during initialisation, power-up and power-down.
-*/
-#if defined(SANSA_CLIP) || defined(SANSA_E200V2) || defined(SANSA_FUZE)
-#define USE_INTERNAL_OSCILLATOR
-#endif
+#define RDSA        0xC /* x */
+#define RDSB        0xD /* x */
+#define RDSC        0xE /* x */
+#define RDSD        0xF /* x */
+
+/* DEVICEID (0x0) */
+#define DEVICEID_PN         (0xf << 12)
+    /* 0x01 = Si4700/01 */
+    /* 0x01 = Si4702/03 */
+#define DEVICEID_MFGID      (0xfff << 0)
+    /* always 0x242 */
+
+/* CHIPID (0x1) */
+
+#if 0 /* Informational */
+/* Si4700/01 */
+#define CHIPID_REV          (0x3f << 10)
+#define CHIPID_DEV          (0x1 << 9)
+    /* 0 before powerup */
+    /* 0 after powerup = Si4700 */
+    /* 1 after powerup = Si4701 */
+#define CHIPID_FIRMWARE     (0xff << 0)
+
+/* Si4702/03 */
+#define CHIPID_REV          (0x3f << 10)
+#define CHIPID_DEV          (0xf << 6)
+    /* 0000 before PU = Si4702 */
+    /* 0001 after PU = Si4702 */
+    /* 1000 before PU = Si4703 */
+    /* 1001 after PU = Si4703 */
+#define CHIPID_FIRMWARE     (0x3f << 0)
+#endif /* 0 */
+
+/* POWERCFG (0x2) */
+#define POWERCFG_DSMUTE     (0x1 << 15)
+#define POWERCFG_DMUTE      (0x1 << 14)
+#define POWERCFG_MONO       (0x1 << 13)
+#define POWERCFG_RDSM       (0x1 << 11) /* x */
+#define POWERCFG_SKMODE     (0x1 << 10)
+#define POWERCFG_SEEKUP     (0x1 <<  9)
+#define POWERCFG_SEEK       (0x1 <<  8)
+#define POWERCFG_DISABLE    (0x1 <<  6)
+#define POWERCFG_ENABLE     (0x1 <<  0)
+
+/* CHANNEL (0x3) */
+#define CHANNEL_TUNE        (0x1 << 15)
+#define CHANNEL_CHAN        (0x3ff << 0)
+    #define CHANNEL_CHANw(x) ((x) & CHANNEL_CHAN)
+
+/* SYSCONFIG1 (0x4) */
+#define SYSCONFIG1_RDSIEN   (0x1 << 15) /* x */
+#define SYSCONFIG1_STCIEN   (0x1 << 14)
+#define SYSCONFIG1_RDS      (0x1 << 12) /* x */
+#define SYSCONFIG1_DE       (0x1 << 11)
+#define SYSCONFIG1_AGCD     (0x1 << 10)
+#define SYSCONFIG1_BLNDADJ  (0x3 <<  6)
+    #define SYSCONFIG1_BLNDADJ_31_39_RSSI (0x0 << 6)
+    #define SYSCONFIG1_BLNDADJ_37_55_RSSI (0x1 << 6)
+    #define SYSCONFIG1_BLNDADJ_19_37_RSSI (0x2 << 6)
+    #define SYSCONFIG1_BLNDADJ_25_43_RSSI (0x3 << 6)
+#define SYSCONFIG1_GPIO3    (0x3 <<  4)
+    #define SYSCONFIG1_GPIO3_HI_Z       (0x0 << 4)
+    #define SYSCONFIG1_GPIO3_MO_ST_I    (0x1 << 4)
+    #define SYSCONFIG1_GPIO3_LOW        (0x2 << 4)
+    #define SYSCONFIG1_GPIO3_HI         (0x3 << 4)
+#define SYSCONFIG1_GPIO2    (0x3 <<  2)
+    #define SYSCONFIG1_GPIO2_HI_Z       (0x0 << 2)
+    #define SYSCONFIG1_GPIO2_STC_RDS_I  (0x1 << 2)
+    #define SYSCONFIG1_GPIO2_LOW        (0x2 << 2)
+    #define SYSCONFIG1_GPIO2_HI         (0x3 << 2)
+#define SYSCONFIG1_GPIO1    (0x3 <<  0)
+    #define SYSCONFIG1_GPIO1_HI_Z       (0x0 << 0)
+    #define SYSCONFIG1_GPIO1_LOW        (0x2 << 0)
+    #define SYSCONFIG1_GPIO1_HI         (0x3 << 0)
+
+/* SYSCONFIG2 (0x5) */
+#define SYSCONFIG2_SEEKTH   (0xff << 8)
+    #define SYSCONFIG2_SKEETHw(x) (((x) << 8) & SYSCONFIG2_SEEKTH)
+#define SYSCONFIG2_BAND     (0x3 << 6)
+    #define SYSCONFIG2_BANDw(x)   (((x) << 6) & SYSCONFIG2_BAND)
+    #define SYSCONFIG2_BANDr(x)   (((x) & SYSCONFIG2_BAND) >> 6)
+    #define SYSCONFIG2_BAND_875_1080    (0x0 << 6) /* tenth-megahertz */
+    #define SYSCONFIG2_BAND_760_1080    (0x1 << 6)
+    #define SYSCONFIG2_BAND_760_900     (0x2 << 6)
+#define SYSCONFIG2_SPACE    (0x3 << 4)
+    #define SYSCONFIG2_SPACEw(x)  (((x) << 4) & SYSCONFIG2_SPACE)
+    #define SYSCONFIG2_SPACEr(x)  (((x) & SYSCONFIG2_SPACE) >> 4)
+    #define SYSCONFIG2_SPACE_200KHZ     (0x0 << 4)
+    #define SYSCONFIG2_SPACE_100KHZ     (0x1 << 4)
+    #define SYSCONFIG2_SPACE_50KHZ      (0x2 << 4)
+/* 4700/01            0000=mute,0001=-28dBFS..2dB steps..1111= +0dBFS */
+/* 4702/03: VOLEXT=0: 0000=mute,0001=-28dBFS..2dB steps..1111= +0dBFS */
+/*          VOLEXT=1: 0000=mute,0001=-58dBFS..2dB steps..1111=-30dBFS */
+#define SYSCONFIG2_VOLUME   (0xf << 0)
+    #define SYSCONFIG2_VOLUMEw(x) ((x) & SYSCONFIG2_VOLUME)
+
+/* SYSCONFIG3 (0x6) */
+#define SYSCONFIG3_SMUTER   (0x3 << 14)
+    #define SYSCONFIG3_SMUTER_FASTEST   (0x0 << 14)
+    #define SYSCONFIG3_SMUTER_FAST      (0x1 << 14)
+    #define SYSCONFIG3_SMUTER_SLOW      (0x2 << 14)
+    #define SYSCONFIG3_SMUTER_SLOWEST   (0x3 << 14)
+#define SYSCONFIG3_SMUTEA   (0x3 << 12)
+    #define SYSCONFIG3_SMUTEA_16DB      (0x0 << 12)
+    #define SYSCONFIG3_SMUTEA_14DB      (0x1 << 12)
+    #define SYSCONFIG3_SMUTEA_12DB      (0x2 << 12)
+    #define SYSCONFIG3_SMUTEA_10DB      (0x3 << 12)
+#define SYSCONFIG3_VOLEXT   (0x1 << 8) /* x */
+#define SYSCONFIG3_SKSNR    (0xf << 4)
+    #define SYSCONFIG3_SKSNRw(x) (((x) << 4) & SYSCONFIG3_SKSNR)
+#define SYSCONFIG3_SKCNT    (0xf << 0)
+    #define SYSCONFIG3_SKCNTw(x) (((x) << 0) & SYSCONFIG3_SKCNT)
+
+/* TEST1 (0x7) */
+/* 4700/01: 15=always 0, 13:0 = write with preexisting values! */
+/* 4702/03:              13:0 = write with preexisting values! */
+#define TEST1_XOSCEN        (0x1 << 15) /* x */
+#define TEST1_AHIZEN        (0x1 << 14)
+
+/* TEST2 (0x8) */
+/* 15:0 = write with preexisting values! */
+
+/* BOOTCONFIG (0x9) */
+/* 15:0 = write with preexisting values! */
+
+/* STATUSRSSI (0xA) */
+#define STATUSRSSI_RDSR     (0x1 << 15) /* x */
+#define STATUSRSSI_STC      (0x1 << 14)
+#define STATUSRSSI_SFBL     (0x1 << 13)
+#define STATUSRSSI_AFCRL    (0x1 << 12)
+#define STATUSRSSI_RDSS     (0x1 << 11) /* x */
+#define STATUSRSSI_BLERA    (0x3 <<  9) /* x */
+#define STATUSRSSI_ST       (0x1 <<  8)
+#define STATUSRSSI_RSSI     (0xff << 0)
+    #define STATUSRSSI_RSSIr(x) ((x) & 0xff)
+
+/* READCHAN (0xB) */
+#define READCHAN_BLERB      (0x3 << 14) /* x */
+#define READCHAN_BLERC      (0x3 << 12) /* x */
+#define READCHAN_BLERD      (0x3 << 10) /* x */
+#define READCHAN_READCHAN   (0x3ff << 0)
+
+/* RDSA-D (0xC-0xF) */
+/* 4702/03: RDS Block A-D data */
 
 static bool tuner_present = false;
-static unsigned short cache[16];
+static int curr_frequency = 87500000; /* Current station frequency (HZ) */
+static uint16_t cache[16];
 
 /* reads <len> registers from radio at offset 0x0A into cache */
 static void si4700_read(int len)
@@ -64,7 +219,7 @@ static void si4700_read(int len)
     int i;
     unsigned char buf[32];
     unsigned char *ptr = buf;
-    unsigned short data;
+    uint16_t data;
     
     fmradio_i2c_read(I2C_ADR, buf, len * 2);
     for (i = 0; i < len; i++) {
@@ -80,8 +235,8 @@ static void si4700_write(int len)
     int i;
     unsigned char buf[32];
     unsigned char *ptr = buf;
-    unsigned short data;
-    
+    uint16_t data;
+
     for (i = 0; i < len; i++) {
         data = cache[(i + POWERCFG) & 0xF];
         *ptr++ = (data >> 8) & 0xFF;
@@ -90,6 +245,43 @@ static void si4700_write(int len)
     fmradio_i2c_write(I2C_ADR, buf, len * 2);
 }
 
+/* Hide silly, wrapped and continuous register reading and make interface
+ * appear sane and normal. This also makes the driver compatible with
+ * using the 3-wire interface. */
+static uint16_t si4700_read_reg(int reg)
+{
+    si4700_read(((reg - STATUSRSSI) & 0xF) + 1);
+    return cache[reg];
+}
+
+static void si4700_write_reg(int reg, uint16_t value)
+{
+    cache[reg] = value;
+    si4700_write(((reg - POWERCFG) & 0xF) + 1);
+}
+
+static void si4700_write_masked(int reg, uint16_t bits, uint16_t mask)
+{
+    si4700_write_reg(reg, (cache[reg] & ~mask) | (bits & mask));
+}
+
+static void si4700_write_set(int reg, uint16_t mask)
+{
+    si4700_write_reg(reg, cache[reg] | mask);
+}
+
+static void si4700_write_clear(int reg, uint16_t mask)
+{
+    si4700_write_reg(reg, cache[reg] & ~mask);
+}
+
+#if (SI4700_GPIO_SETUP & SYSCONFIG1_GPIO3) != SYSCONFIG1_GPIO3_MO_ST_I
+/* Poll i2c for the stereo status */
+static inline int si4700_st(void)
+{
+    return (si4700_read_reg(STATUSRSSI) & STATUSRSSI_ST) >> 8;
+}
+#endif
 
 void si4700_init(void)
 {
@@ -105,8 +297,7 @@ void si4700_init(void)
 
 #ifdef USE_INTERNAL_OSCILLATOR
         /* enable the internal oscillator */
-        cache[TEST1] |= (1 << 15);  /* XOSCEN */
-        si4700_write(6);
+        si4700_write_set(TEST1, TEST1_XOSCEN);
         sleep(HZ/2);
 #endif    
     }
@@ -114,21 +305,102 @@ void si4700_init(void)
     tuner_power(false);
 }
 
-static void si4700_tune(void)
+static void si4700_sleep(int snooze)
 {
-    cache[CHANNEL] |= (1 << 15); /* Set TUNE high to start tuning */
-    si4700_write(2);
+    if (snooze)
+    {
+        /** power down **/
+        /* ENABLE high, DISABLE high */
+        si4700_write_set(POWERCFG,
+                         POWERCFG_DISABLE | POWERCFG_ENABLE);
+        /* Bits self-clear once placed in powerdown. */
+        cache[POWERCFG] &= ~(POWERCFG_DISABLE | POWERCFG_ENABLE);
+    }
+    else
+    {
+        /** power up **/
+        /* ENABLE high, DISABLE low */
+        si4700_write_masked(POWERCFG, POWERCFG_ENABLE,
+                            POWERCFG_DISABLE | POWERCFG_ENABLE);
+        sleep(110 * HZ / 1000);
+
+        /* init register cache */
+        si4700_read(16);
+
+#if SI4700_GPIO_SETUP != 0
+        si4700_write_masked(SYSCONFIG1, SI4700_GPIO_SETUP, 
+                            SYSCONFIG1_GPIO1 | SYSCONFIG1_GPIO2 |
+                            SYSCONFIG1_GPIO3);
+#endif
+        /* -6dB volume, seek threshold 12 */
+        si4700_write_masked(SYSCONFIG2,
+                            SYSCONFIG2_SKEETHw(SEEK_THRESHOLD) |
+                            SYSCONFIG2_VOLUMEw(TUNER_VOLUME),
+                            SYSCONFIG2_VOLUME | SYSCONFIG2_SEEKTH);
+    }
+}
+
+static void si4700_set_frequency(int freq)
+{
+    static const unsigned int spacings[3] =
+    {
+          200000, /* SYSCONFIG2_SPACE_200KHZ */
+          100000, /* SYSCONFIG2_SPACE_100KHZ */
+           50000, /* SYSCONFIG2_SPACE_50KHZ  */
+    };
+    static const unsigned int bands[3] =
+    {
+        87500000, /* SYSCONFIG2_BAND_875_1080 */
+        76000000, /* SYSCONFIG2_BAND_760_1080 */
+        76000000, /* SYSCONFIG2_BAND_760_900  */
+    };
+
+    /* check BAND and spacings */
+    int space = SYSCONFIG2_SPACEr(cache[SYSCONFIG2]);
+    int band = SYSCONFIG2_BANDr(cache[SYSCONFIG2]);
+    int chan = (freq - bands[band]) / spacings[space];
+
+    curr_frequency = freq;
+
+    si4700_write_reg(CHANNEL, CHANNEL_CHANw(chan) | CHANNEL_TUNE);
 
     do
     {
         /* tuning should be done within 60 ms according to the datasheet */
         sleep(HZ * 60 / 1000);
-        si4700_read(2);
     }
-    while (!(cache[STATUSRSSI] & (1 << 14))); /* STC high */
+    while ((si4700_read_reg(STATUSRSSI) & STATUSRSSI_STC) == 0); /* STC high? */
 
-    cache[CHANNEL] &= ~(1 << 15); /* Set TUNE low */
-    si4700_write(2);
+    si4700_write_clear(CHANNEL, CHANNEL_TUNE); /* Set TUNE low */
+}
+
+static int si4700_tuned(void)
+{
+    /* Primitive tuning check: sufficient level and AFC not railed */
+    uint16_t status = si4700_read_reg(STATUSRSSI);
+    if (STATUSRSSI_RSSIr(status) >= SEEK_THRESHOLD &&
+        (status & STATUSRSSI_AFCRL) == 0)
+        return 1;
+
+    return 0;
+}
+
+static void si4700_set_region(int region)
+{
+    const struct si4700_region_data *rd = &si4700_region_data[region];
+    uint16_t bandspacing = SYSCONFIG2_BANDw(rd->band) |
+                           SYSCONFIG2_SPACEw(rd->spacing);
+    uint16_t oldbs = cache[SYSCONFIG2] & (SYSCONFIG2_BAND | SYSCONFIG2_SPACE);
+
+    si4700_write_masked(SYSCONFIG1,
+                        rd->deemphasis ? SYSCONFIG1_DE : 0,
+                        SYSCONFIG1_DE);
+    si4700_write_masked(SYSCONFIG2, bandspacing,
+                        SYSCONFIG2_BAND | SYSCONFIG2_SPACE);
+
+    /* Retune if this region change would change the channel number. */
+    if (oldbs != bandspacing)
+        si4700_set_frequency(curr_frequency);
 }
 
 /* tuner abstraction layer: set something to the tuner */
@@ -137,95 +409,35 @@ int si4700_set(int setting, int value)
     switch(setting)
     {
         case RADIO_SLEEP:
-            if (value)
-            {
-                /* power down */
-                cache[POWERCFG] = (1 | (1 << 6)); /* ENABLE high, DISABLE high */
-                si4700_write(1);
-            }
-            else
-            {
-                /* power up */
-                cache[POWERCFG] = 1; /* ENABLE high, DISABLE low */
-                si4700_write(1);
-                sleep(110 * HZ / 1000);
-                
-                /* update register cache */
-                si4700_read(16);               
-
-                /* -6dB volume, keep everything else as default */
-                cache[SYSCONFIG2] = (cache[SYSCONFIG2] & ~0xF) | 0xC;
-                si4700_write(5);
-            }
-            return 1;
+            si4700_sleep(value);
+            break;
 
         case RADIO_FREQUENCY:
-        {
-            static const unsigned int spacings[3] =
-            {
-                200000, 100000, 50000
-            };
-            unsigned int chan;
-            unsigned int spacing = spacings[(cache[5] >> 4) & 3] ;
-
-            if (cache[SYSCONFIG2] & (3 << 6)) /* check BAND */
-            {
-                chan = (value - 76000000) / spacing;
-            }
-            else
-            {
-                chan = (value - 87500000) / spacing;
-            }
-
-            cache[CHANNEL] = (cache[CHANNEL] & ~0x3FF) | chan;
-            si4700_tune();
-            return 1;
-        }
+            si4700_set_frequency(value);
+            break;
 
         case RADIO_SCAN_FREQUENCY:
-            si4700_set(RADIO_FREQUENCY, value);
-            return 1;
+            si4700_set_frequency(value);
+            return si4700_tuned();
 
         case RADIO_MUTE:
-            if (value)
-            {
-                /* mute */
-                cache[POWERCFG] &= ~(1 << 14);
-            }
-            else
-            {
-                /* unmute */
-                cache[POWERCFG] |= (1 << 14);
-            }
+            si4700_write_masked(POWERCFG, value ? 0 : POWERCFG_DMUTE,
+                                POWERCFG_DMUTE);
             break;
 
         case RADIO_REGION:
-        {
-            const struct si4700_region_data *rd =
-                &si4700_region_data[value];
-
-            cache[SYSCONFIG1] = (cache[SYSCONFIG1] & ~(1 << 11)) | (rd->deemphasis << 11);
-            cache[SYSCONFIG2] = (cache[SYSCONFIG2] & ~(3 << 6)) | (rd->band << 6);
-            cache[SYSCONFIG2] = (cache[SYSCONFIG2] & ~(3 << 4)) | (rd->spacing << 4);
+            si4700_set_region(value);
             break;
-        }
 
         case RADIO_FORCE_MONO:
-            if (value)
-            {
-                cache[POWERCFG] |= (1 << 13);
-            }
-            else
-            {
-                cache[POWERCFG] &= ~(1 << 13);
-            }
+            si4700_write_masked(POWERCFG, value ? POWERCFG_MONO : 0,
+                                POWERCFG_MONO);
             break;
 
         default:
             return -1;
     }
 
-    si4700_write(5);
     return 1;
 }
 
@@ -241,15 +453,25 @@ int si4700_get(int setting)
             break;
 
         case RADIO_TUNED:
-            val = 1;
+            val = si4700_tuned();
             break;
 
         case RADIO_STEREO:
-            si4700_read(1);
-            val = (cache[STATUSRSSI] & (1 << 8)); /* ST high == Stereo */
+            val = si4700_st();
             break;
     }
 
     return val;
 }
 
+void si4700_dbg_info(struct si4700_dbg_info *nfo)
+{
+    memset(nfo->regs, 0, sizeof (nfo->regs));
+
+    if (tuner_powered())
+    {
+        si4700_read(16);
+        memcpy(nfo->regs, cache, sizeof (nfo->regs));
+    }
+}
+
diff --git a/firmware/export/imx31l.h b/firmware/export/imx31l.h
index 6780a5a43f..5a964b8e2e 100755
--- a/firmware/export/imx31l.h
+++ b/firmware/export/imx31l.h
@@ -202,26 +202,33 @@
 #define SW_MUX_CTL_GPIO1_0_GPIO1_1_GPIO1_2_GPIO1_3                      IOMUXC_(0x14C)
 #define SW_MUX_CTL_CAPTURE_COMPARE_WATCHDOG_RST_PWMO                    IOMUXC_(0x150)
 
-#define SW_MUX_OUT_EN_GPIO_DR   0x0
-#define SW_MUX_OUT_FUNCTIONAL   0x1
-#define SW_MUX_OUT_ALTERNATE_1  0x2
-#define SW_MUX_OUT_ALTERNATE_2  0x3
-#define SW_MUX_OUT_ALTERNATE_3  0x4
-#define SW_MUX_OUT_ALTERNATE_4  0x5
-#define SW_MUX_OUT_ALTERNATE_5  0x6
-#define SW_MUX_OUT_ALTERNATE_6  0x7
-
-#define SW_MUX_IN_NO_INPUTS     0x0
-#define SW_MUX_IN_GPIO_PSR_ISR  0x1
-#define SW_MUX_IN_FUNCTIONAL    0x2
-#define SW_MUX_IN_ALTERNATE_1   0x3
-#define SW_MUX_IN_ALTERNATE_2   0x4
-
+#define SW_MUX_OUT              (0x7 << 4)
+#define SW_MUX_OUT_GPIO_DR      (0x0 << 4)
+#define SW_MUX_OUT_FUNCTIONAL   (0x1 << 4)
+#define SW_MUX_OUT_ALT1         (0x2 << 4)
+#define SW_MUX_OUT_ALT2         (0x3 << 4)
+#define SW_MUX_OUT_ALT3         (0x4 << 4)
+#define SW_MUX_OUT_ALT4         (0x5 << 4)
+#define SW_MUX_OUT_ALT5         (0x6 << 4)
+#define SW_MUX_OUT_ALT6         (0x7 << 4)
+
+#define SW_MUX_IN               (0xf << 0)
+#define SW_MUX_IN_NO_INPUTS     (0x0 << 0)
+#define SW_MUX_IN_GPIO_PSR_ISR  (0x1 << 0)
+#define SW_MUX_IN_FUNCTIONAL    (0x2 << 0)
+#define SW_MUX_IN_ALT1          (0x4 << 0)
+#define SW_MUX_IN_ALT2          (0x8 << 0)
+
+/* Masks for each signal field */
+#define SW_MUX_CTL_SIG1         (0x7f <<  0)
+#define SW_MUX_CTL_SIG2         (0x7f <<  8)
+#define SW_MUX_CTL_SIG3         (0x7f << 16)
+#define SW_MUX_CTL_SIG4         (0x7f << 24)
 /* Shift above flags into one of the four fields in each register */
-#define SW_MUX_CTL_FLD_0(x)     ((x) << 0)
-#define SW_MUX_CTL_FLD_1(x)     ((x) << 8)
-#define SW_MUX_CTL_FLD_2(x)     ((x) << 16)
-#define SW_MUX_CTL_FLD_3(x)     ((x) << 24)
+#define SW_MUX_CTL_SIG1w(x)     (((x) <<  0) & SW_MUX_CTL_SIG1)
+#define SW_MUX_CTL_SIG2w(x)     (((x) <<  8) & SW_MUX_CTL_SIG2)
+#define SW_MUX_CTL_SIG3w(x)     (((x) << 16) & SW_MUX_CTL_SIG3)
+#define SW_MUX_CTL_SIG4w(x)     (((x) << 24) & SW_MUX_CTL_SIG4)
 
 /* SW_PAD_CTL */
 #define SW_PAD_CTL_TTM_PAD__X__X                            IOMUXC_(0x154)
@@ -336,36 +343,39 @@
 #define SW_PAD_CTL_CAPTURE_COMPARE_WATCHDOG_RST             IOMUXC_(0x308)
 
 /* SW_PAD_CTL flags */
-#define SW_PAD_CTL_LOOPBACK                         (1 << 9)
-#define SW_PAD_CTL_DISABLE_PULL_UP_DOWN_AND_KEEPER  (0 << 7)
-#if 0 /* Same as 0 */
-#define SW_PAD_CTL_DISABLE_PULL_UP_DOWN_AND_KEEPER  (1 << 7)
-#endif
-#define SW_PAD_CTL_ENABLE_KEEPER                    (2 << 7)
-#define SW_PAD_CTL_ENABLE_PULL_UP_OR_PULL_DOWN      (3 << 7)
-#define SW_PAD_CTL_100K_PULL_DOWN                   (0 << 5)
-#define SW_PAD_CTL_100K_PULL_UP                     (1 << 5)
+#define SW_PAD_CTL_LOOPBACK             (0x1 << 9) /* Route output to input */
+/* Pullup, pulldown and keeper enable */
+#define SW_PAD_CTL_PUE_PKE              (0x3 << 7)
+#define SW_PAD_CTL_PUE_PKE_DISABLE      (0x0 << 7)
+#define SW_PAD_CTL_PUE_PKE_DISABLE_2    (0x1 << 7) /* Same as 0x0 */
+#define SW_PAD_CTL_PUE_PKE_KEEPER       (0x2 << 7)
+#define SW_PAD_CTL_PUE_PKE_PULLUPDOWN   (0x3 << 7) /* Enb. Pull up or down */
+/* Pullup/down resistance */
+#define SW_PAD_CTL_PUS                  (0x3 << 5)
+#define SW_PAD_CTL_PUS_DOWN_100K        (0x0 << 5)
+#define SW_PAD_CTL_PUS_UP_100K          (0x1 << 5)
 #if 0 /* Completeness */
-#define SW_PAD_CTL_47K_PULL_UP                      (2 << 5) /* Not in IMX31/L */
-#define SW_PAD_CTL_22K_PULL_UP                      (3 << 5) /* Not in IMX31/L */
-#endif
-#define SW_PAD_CTL_IPP_HYS_STD                      (0 << 4)
-#define SW_PAD_CTL_IPP_HYS_SCHIMDT                  (1 << 4)
-#define SW_PAD_CTL_IPP_ODE_CMOS                     (0 << 3)
-#define SW_PAD_CTL_IPP_ODE_OPEN                     (1 << 3)
-#define SW_PAD_CTL_IPP_DSE_STD                      (0 << 1)
-#define SW_PAD_CTL_IPP_DSE_HIGH                     (1 << 1)
-#define SW_PAD_CTL_IPP_DSE_MAX                      (2 << 1)
-#if 0 /* Same as 2 */
-#define SW_PAD_CTL_IPP_DSE_MAX                      (3 << 1)
+#define SW_PAD_CTL_PUS_UP_47K           (0x2 << 5) /* Not in IMX31/L */
+#define SW_PAD_CTL_PUS_UP_22K           (0x3 << 5) /* Not in IMX31/L */
 #endif
-#define SW_PAD_CTL_IPP_SRE_SLOW                     (0 << 0)
-#define SW_PAD_CTL_IPP_SRE_FAST                     (1 << 0)
+#define SW_PAD_CTL_HYS                  (0x1 << 4) /* Schmitt trigger input */
+#define SW_PAD_CTL_ODE                  (0x1 << 3) /* Open drain output 0=CMOS pushpull*/
+#define SW_PAD_CTL_DSE                  (0x3 << 1)
+#define SW_PAD_CTL_DSE_STD              (0x0 << 1) /* Drive strength */
+#define SW_PAD_CTL_DSE_HIGH             (0x1 << 1)
+#define SW_PAD_CTL_DSE_MAX              (0x2 << 1)
+#define SW_PAD_CTL_DSE_MAX_2            (0x3 << 1) /* Same as 0x2 */
+#define SW_PAD_CTL_SRE                  (0x1 << 0) /* Slew rate, 1=fast */
+
+/* Masks for each IO field */
+#define SW_PAD_CTL_IO1                  (0x3ff << 0)
+#define SW_PAD_CTL_IO2                  (0x3ff << 10)
+#define SW_PAD_CTL_IO3                  (0x3ff << 20)
 
 /* Shift above flags into one of the three fields in each register */
-#define SW_PAD_CTL_FLD_0(x)                         ((x) << 0)
-#define SW_PAD_CTL_FLD_1(x)                         ((x) << 10)
-#define SW_PAD_CTL_FLD_2(x)                         ((x) << 20)
+#define SW_PAD_CTL_IO1w(x)              (((x) <<  0) & SW_PAD_CTL_IO1)
+#define SW_PAD_CTL_IO2w(x)              (((x) << 10) & SW_PAD_CTL_IO2)
+#define SW_PAD_CTL_IO3w(x)              (((x) << 20) & SW_PAD_CTL_IO3)
 
 /* RNGA */
 #define RNGA_CONTROL            (*(REG32_PTR_T)(RNGA_BASE_ADDR+0x00))
diff --git a/firmware/export/power.h b/firmware/export/power.h
index edf43f8cc8..5cd6996eff 100644
--- a/firmware/export/power.h
+++ b/firmware/export/power.h
@@ -95,6 +95,7 @@ bool spdif_powered(void);
 
 #if CONFIG_TUNER
 bool tuner_power(bool status);
+bool tuner_powered(void);
 #endif
 
 #endif /* _POWER_H_ */
diff --git a/firmware/export/si4700.h b/firmware/export/si4700.h
index 89905ee155..fcc71cb282 100644
--- a/firmware/export/si4700.h
+++ b/firmware/export/si4700.h
@@ -36,9 +36,15 @@ struct si4700_region_data
 
 extern const struct si4700_region_data si4700_region_data[TUNER_NUM_REGIONS];
 
+struct si4700_dbg_info
+{
+    uint16_t regs[16];  /* Read registers */
+};
+
 void si4700_init(void);
 int si4700_set(int setting, int value);
 int si4700_get(int setting);
+void si4700_dbg_info(struct si4700_dbg_info *nfo);
 
 #ifndef CONFIG_TUNER_MULTI
 #define tuner_set si4700_set
diff --git a/firmware/target/arm/as3525/power-as3525.c b/firmware/target/arm/as3525/power-as3525.c
index 07867546c2..2fbeab0bc6 100644
--- a/firmware/target/arm/as3525/power-as3525.c
+++ b/firmware/target/arm/as3525/power-as3525.c
@@ -54,9 +54,21 @@ void ide_power_enable(bool on)
 }
 
 #if CONFIG_TUNER
+static bool tuner_on = false;
+
 bool tuner_power(bool status)
 {
-    (void)status;
-    return false;
+    if (status != tuner_on)
+    {
+        tuner_on = status;
+        status = !status;
+    }
+
+    return status;    
+}
+
+bool tuner_powered(void)
+{
+    return tuner_on; /* No debug info */
 }
 #endif
diff --git a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
index 154e13f9a7..7646402435 100644
--- a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
@@ -21,6 +21,7 @@
  ****************************************************************************/
 #include "config.h"
 #include "system.h"
+#include "mc13783.h"
 #include "i2c-imx31.h"
 #include "fmradio_i2c.h"
 
@@ -33,9 +34,77 @@ static struct i2c_node si4700_i2c_node =
     .addr = (0x20),
 };
 
+void fmradio_i2c_init(void)
+{
+    /* RST: LOW */
+    imx31_regclr32(&GPIO1_DR, (1 << 26));
+    /* RST: OUT */
+    imx31_regset32(&GPIO1_GDIR, (1 << 26));
+
+    /* I2C2 SCL: IN, I2C2: SDA IN */
+    imx31_regclr32(&GPIO2_GDIR, (3 << 14));
+    /* I2C2 SCL LO, I2C2 SDA LO */
+    imx31_regclr32(&GPIO2_DR, (3 << 14));
+
+    /* open-drain pins - external pullups on PCB. Pullup default but
+     * disabled */
+    imx31_regmod32(&SW_PAD_CTL_DSR_DTE1_RI_DTE1_DCD_DTE1,
+        /* RI_DTE1 (I2C2_SCLK) */
+        SW_PAD_CTL_IO2w(SW_PAD_CTL_PUE_PKE_DISABLE |
+                        SW_PAD_CTL_PUS_UP_100K |
+                        SW_PAD_CTL_HYS |
+                        SW_PAD_CTL_ODE) |
+        /* DCD_DTE1 (I2C2_SDA) */
+        SW_PAD_CTL_IO1w(SW_PAD_CTL_PUE_PKE_DISABLE |
+                        SW_PAD_CTL_PUS_UP_100K |
+                        SW_PAD_CTL_HYS |
+                        SW_PAD_CTL_ODE),
+        SW_PAD_CTL_IO2 | SW_PAD_CTL_IO1);
+    /* set outputs to I2C2 */
+    imx31_regmod32(&SW_MUX_CTL_RI_DTE1_DCD_DTE1_DTR_DCE2_RXD2,
+       /* RI_DTE1 => I2C2_SCLK */
+       SW_MUX_CTL_SIG4w(SW_MUX_OUT_ALT2 | SW_MUX_IN_ALT2) |
+       /* DCD_DTE1 => I2C2_SDA */
+       SW_MUX_CTL_SIG3w(SW_MUX_OUT_ALT2 | SW_MUX_IN_ALT2),
+       SW_MUX_CTL_SIG4 | SW_MUX_CTL_SIG3);
+}
+
 void fmradio_i2c_enable(bool enable)
 {
-    i2c_enable_node(&si4700_i2c_node, enable);
+    if (enable)
+    {
+        uint32_t io_pin_mux = SW_MUX_CTL_RI_DTE1_DCD_DTE1_DTR_DCE2_RXD2;
+        /* place in GPIO mode to hold SDIO low during RESET release,
+         * SEN1 should be high already (pullup) and GPIO3 left alone */
+        imx31_regset32(&GPIO2_GDIR, (1 << 15)); /* SDIO OUT */
+        /* I2C2_SDA => MCU2_15 */ 
+        imx31_regmod32(&SW_MUX_CTL_RI_DTE1_DCD_DTE1_DTR_DCE2_RXD2,
+            SW_MUX_CTL_SIG3w(SW_MUX_OUT_GPIO_DR | SW_MUX_IN_GPIO_PSR_ISR),
+            SW_MUX_CTL_SIG3);
+        /* enable CLK32KMCU clock */
+        mc13783_set(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
+        /* enable the fm chip (release RESET) */
+        imx31_regset32(&GPIO1_DR, (1 << 26));
+        sleep(HZ/100);
+        /* busmode should be selected - OK to release SDIO */
+        imx31_regclr32(&GPIO2_GDIR, (1 << 15)); /* SDIO IN */
+        /* restore pin mux (DCD_DTE1 => I2C2_SDA) */
+        imx31_regmod32(&SW_MUX_CTL_RI_DTE1_DCD_DTE1_DTR_DCE2_RXD2,
+                       io_pin_mux, SW_MUX_CTL_SIG3);
+        /* the si4700 is the only thing connected to i2c2 so
+           we can diable the i2c module when not in use */
+        i2c_enable_node(&si4700_i2c_node, true);
+    }
+    else
+    {
+        /* the si4700 is the only thing connected to i2c2 so
+           we can diable the i2c module when not in use */
+        i2c_enable_node(&si4700_i2c_node, false);
+        /* disable the fm chip */
+        imx31_regclr32(&GPIO1_DR, (1 << 26));
+        /* disable CLK32KMCU clock */
+        mc13783_clear(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
+    }
 }
 
 int fmradio_i2c_write(unsigned char address, const unsigned char* buf, int count)
@@ -52,3 +121,7 @@ int fmradio_i2c_read(unsigned char address, unsigned char* buf, int count)
     return 0;
 }
 
+int si4700_st(void)
+{
+    return (GPIO1_DR & (1 << 28)) >> 28;
+}
diff --git a/firmware/target/arm/imx31/gigabeat-s/power-imx31.c b/firmware/target/arm/imx31/gigabeat-s/power-imx31.c
index 727b38bd96..b29d3cd0fb 100644
--- a/firmware/target/arm/imx31/gigabeat-s/power-imx31.c
+++ b/firmware/target/arm/imx31/gigabeat-s/power-imx31.c
@@ -98,37 +98,24 @@ bool ide_powered(void)
 }
 
 #if CONFIG_TUNER
+static bool tuner_on = false;
+
 bool tuner_power(bool status)
 {
-    static bool tuner_powered = false;
-
-    if (status == tuner_powered)
-        return status;
-
-    tuner_powered = status;
-
-    if (status)
-    {
-        /* the si4700 is the only thing connected to i2c2 so
-           we can diable the i2c module when not in use */
-        fmradio_i2c_enable(true);
-        /* enable the fm chip */
-        imx31_regset32(&GPIO1_DR, (1 << 26));
-        /* enable CLK32KMCU clock */
-        mc13783_set(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
-    }
-    else
+    if (status != tuner_on)
     {
-        /* the si4700 is the only thing connected to i2c2 so
-           we can diable the i2c module when not in use */
-        fmradio_i2c_enable(false);
-        /* disable the fm chip */
-        imx31_regclr32(&GPIO1_DR, (1 << 26));
-        /* disable CLK32KMCU clock */
-        mc13783_clear(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
+        tuner_on = status;
+        /* Handle power and pin setup */
+        fmradio_i2c_enable(status);
+        status = !status;
     }
 
-    return !status;
+    return status;
+}
+
+bool tuner_powered(void)
+{
+    return tuner_on;
 }
 #endif /* #if CONFIG_TUNER */
 
@@ -151,6 +138,10 @@ void power_off(void)
 
 void power_init(void)
 {
+#if CONFIG_TUNER
+    fmradio_i2c_init();
+#endif
+
     /* Poll initial state */
     charger_main_detect_event();
 
diff --git a/firmware/tuner.c b/firmware/tuner.c
index c694031c45..c5da27079c 100644
--- a/firmware/tuner.c
+++ b/firmware/tuner.c
@@ -64,7 +64,7 @@ const struct si4700_region_data si4700_region_data[TUNER_NUM_REGIONS] =
 {
     [REGION_EUROPE]    = { 1, 0, 2 }, /* 50uS, US/Europe band,  50kHz spacing */
     [REGION_US_CANADA] = { 0, 0, 0 }, /* 75uS, US/Europe band, 200kHz spacing */
-    [REGION_JAPAN]     = { 1, 1, 1 }, /* 50uS, Japanese band,  100kHz spacing */
+    [REGION_JAPAN]     = { 1, 2, 1 }, /* 50uS, Japanese band,  100kHz spacing */
     [REGION_KOREA]     = { 1, 0, 1 }, /* 50uS, US/Europe band, 100kHz spacing */
 };
 #endif /* (CONFIG_TUNER & SI4700) */