15 files changed, 267 insertions, 207 deletions

diff --git a/firmware/export/as3525.h b/firmware/export/as3525.h
index 87e3fc43d7..c5e01d5bc8 100644
--- a/firmware/export/as3525.h
+++ b/firmware/export/as3525.h
@@ -526,7 +526,6 @@ CE lines
 
 /* PCM addresses for obtaining buffers will be what DMA is using (physical) */
 #define HAVE_PCM_DMA_ADDRESS
-#define HAVE_PCM_REC_DMA_ADDRESS
 
 /* Timer frequency */
 #define TIMER_FREQ (24000000 / 16)
diff --git a/firmware/export/config/sansac200v2.h b/firmware/export/config/sansac200v2.h
index 4223d41b92..a5b857fe81 100644
--- a/firmware/export/config/sansac200v2.h
+++ b/firmware/export/config/sansac200v2.h
@@ -14,7 +14,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansaclip.h b/firmware/export/config/sansaclip.h
index 7427d623fb..4e214669b1 100644
--- a/firmware/export/config/sansaclip.h
+++ b/firmware/export/config/sansaclip.h
@@ -14,7 +14,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansaclipplus.h b/firmware/export/config/sansaclipplus.h
index 8a0a0403f3..0ae67b70d0 100644
--- a/firmware/export/config/sansaclipplus.h
+++ b/firmware/export/config/sansaclipplus.h
@@ -21,7 +21,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansaclipv2.h b/firmware/export/config/sansaclipv2.h
index a39fe3e12c..d7a50afa20 100644
--- a/firmware/export/config/sansaclipv2.h
+++ b/firmware/export/config/sansaclipv2.h
@@ -14,7 +14,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansaclipzip.h b/firmware/export/config/sansaclipzip.h
index 3df9ed57fd..e0f39afcf1 100644
--- a/firmware/export/config/sansaclipzip.h
+++ b/firmware/export/config/sansaclipzip.h
@@ -21,7 +21,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansae200v2.h b/firmware/export/config/sansae200v2.h
index 34c2cd98ad..a03dfe05a6 100644
--- a/firmware/export/config/sansae200v2.h
+++ b/firmware/export/config/sansae200v2.h
@@ -12,7 +12,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/config/sansafuze.h b/firmware/export/config/sansafuze.h
index 8563664cb8..2e9c261a04 100644
--- a/firmware/export/config/sansafuze.h
+++ b/firmware/export/config/sansafuze.h
@@ -12,7 +12,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Default recording levels */
 #define DEFAULT_REC_MIC_GAIN    23
diff --git a/firmware/export/config/sansafuzev2.h b/firmware/export/config/sansafuzev2.h
index 1c0f8a99dc..7465010166 100644
--- a/firmware/export/config/sansafuzev2.h
+++ b/firmware/export/config/sansafuzev2.h
@@ -12,7 +12,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Default recording levels */
 #define DEFAULT_REC_MIC_GAIN    23
diff --git a/firmware/export/config/sansam200v4.h b/firmware/export/config/sansam200v4.h
index 88679c1a78..52b10a4431 100644
--- a/firmware/export/config/sansam200v4.h
+++ b/firmware/export/config/sansam200v4.h
@@ -16,7 +16,14 @@
 /* define this if you have recording possibility */
 #define HAVE_RECORDING
 
-#define REC_SAMPR_CAPS      SAMPR_CAP_ALL
+#define REC_SAMPR_CAPS      (SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
+                             SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
+                             SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
+
+/* because the samplerates don't match at each point, we must be able to
+ * tell PCM which set of rates to use. not needed if recording rates are
+ * a simple subset of playback rates and are equal values. */
+#define CONFIG_SAMPR_TYPES
 
 /* Define bitmask of input sources - recordable bitmask can be defined
    explicitly if different */
diff --git a/firmware/export/pcm_sampr.h b/firmware/export/pcm_sampr.h
index 62bfd0068b..01a8ed428e 100644
--- a/firmware/export/pcm_sampr.h
+++ b/firmware/export/pcm_sampr.h
@@ -305,6 +305,8 @@ enum rec_freq_indexes
 #define REC_SAMPR_DEFAULT SAMPR_44
 #endif
 
+#define HW_SAMPR_RESET  0
+
 #define REC_FREQ_CFG_VAL_LIST  &REC_HAVE_96_(",96") REC_HAVE_88_(",88") \
                                 REC_HAVE_64_(",64") REC_HAVE_48_(",48") \
                                 REC_HAVE_44_(",44") REC_HAVE_32_(",32") \
@@ -324,7 +326,8 @@ extern const unsigned long rec_freq_sampr[REC_NUM_FREQ];
 #define SAMPR_TYPE_REC  (0x01 << 24)
 #endif
 
-unsigned int pcm_sampr_type_rec_to_play(unsigned int samplerate);
+unsigned int pcm_sampr_to_hw_sampr(unsigned int samplerate,
+                                   unsigned int type);
 
 #else /* ndef CONFIG_SAMPR_TYPES */
 
diff --git a/firmware/pcm.c b/firmware/pcm.c
index f5efb4f84e..d1a897dcab 100644
--- a/firmware/pcm.c
+++ b/firmware/pcm.c
@@ -393,21 +393,14 @@ void pcm_set_frequency(unsigned int samplerate)
     int index;
 
 #ifdef CONFIG_SAMPR_TYPES
-#ifdef HAVE_RECORDING
     unsigned int type = samplerate & SAMPR_TYPE_MASK;
-#endif
     samplerate &= ~SAMPR_TYPE_MASK;
 
-#ifdef HAVE_RECORDING
-#if SAMPR_TYPE_REC != 0
     /* For now, supported targets have direct conversion when configured with
      * CONFIG_SAMPR_TYPES.
      * Some hypothetical target with independent rates would need slightly
      * different handling throughout this source. */
-    if (type == SAMPR_TYPE_REC)
-        samplerate = pcm_sampr_type_rec_to_play(samplerate);
-#endif
-#endif /* HAVE_RECORDING */
+    samplerate = pcm_sampr_to_hw_sampr(samplerate, type);
 #endif /* CONFIG_SAMPR_TYPES */
 
     index = round_value_to_list32(samplerate, hw_freq_sampr,
diff --git a/firmware/target/arm/as3525/audio-as3525.c b/firmware/target/arm/as3525/audio-as3525.c
index 10c6161881..e4bb39b406 100644
--- a/firmware/target/arm/as3525/audio-as3525.c
+++ b/firmware/target/arm/as3525/audio-as3525.c
@@ -24,16 +24,33 @@
 #include "audio.h"
 #include "audiohw.h"
 #include "sound.h"
+#include "general.h"
 
 int audio_channels = 2;
 
+#if CONFIG_CPU == AS3525
+int audio_output_source = AUDIO_SRC_PLAYBACK;
+#endif
+
 void audio_set_output_source(int source)
 {
     bitset32(&CGU_PERI, CGU_I2SOUT_APB_CLOCK_ENABLE);
-    if (source == AUDIO_SRC_PLAYBACK)
-        I2SOUT_CONTROL &= ~(1<<5);
+
+    if ((unsigned)source >= AUDIO_NUM_SOURCES)
+        source = AUDIO_SRC_PLAYBACK;
+
+    bool loopback = source != AUDIO_SRC_PLAYBACK;
+
+#if CONFIG_CPU == AS3525
+    loopback = loopback && audio_channels > 1;
+
+    audio_output_source = source;
+#endif
+
+    if (loopback)
+        I2SOUT_CONTROL |= (1<<5);  /* loopback from i2sin fifo */
     else
-        I2SOUT_CONTROL |= 1<<5; /* source = loopback from i2sin fifo */
+        I2SOUT_CONTROL &= ~(1<<5); /* normal i2sout */
 }
 
 void audio_input_mux(int source, unsigned flags)
@@ -108,4 +125,33 @@ void audio_input_mux(int source, unsigned flags)
     }
 
     last_source = source;
+
+#if CONFIG_CPU == AS3525
+    /* Sync on behalf of change in number of channels */
+    audio_set_output_source(audio_output_source);
+#endif
 }
+
+#ifdef CONFIG_SAMPR_TYPES
+unsigned int pcm_sampr_to_hw_sampr(unsigned int samplerate,
+                                   unsigned int type)
+{
+#ifdef HAVE_RECORDING
+    if (samplerate != HW_SAMPR_RESET && type == SAMPR_TYPE_REC)
+    {
+        /* Check if the samplerate is in the list of recordable rates.
+         * Fail to default if not */
+        int index = round_value_to_list32(samplerate, rec_freq_sampr,
+                                          REC_NUM_FREQ, false);
+        if (samplerate != rec_freq_sampr[index])
+            samplerate = REC_SAMPR_DEFAULT;
+
+        samplerate *= 2; /* Recording rates are 1/2 the codec clock */
+    }
+#endif /* HAVE_RECORDING */
+
+    return samplerate;
+    (void)type;
+}
+#endif /* CONFIG_SAMPR_TYPES */
+
diff --git a/firmware/target/arm/as3525/pcm-as3525.c b/firmware/target/arm/as3525/pcm-as3525.c
index f82b373ade..8b42bbd5b2 100644
--- a/firmware/target/arm/as3525/pcm-as3525.c
+++ b/firmware/target/arm/as3525/pcm-as3525.c
@@ -43,9 +43,14 @@ static size_t dma_rem_size;     /* Remaining size - in 4*32 bits */
 static size_t play_sub_size;    /* size of current subtransfer */
 static void dma_callback(void);
 static int locked = 0;
-static bool is_playing = false;
+static bool volatile is_playing = false;
 static bool play_callback_pending = false;
 
+#ifdef HAVE_RECORDING
+/* Stopping playback gates clock if not recording */
+static bool volatile is_recording = false;
+#endif
+
 /* Mask the DMA interrupt */
 void pcm_play_lock(void)
 {
@@ -116,26 +121,27 @@ static void dma_callback(void)
 
 void pcm_play_dma_start(const void *addr, size_t size)
 {
+    is_playing = true;
+
     dma_start_addr = (void*)addr;
     dma_start_size = size;
     dma_sub_addr = dma_start_addr;
     dma_rem_size = size;
 
-    bitset32(&CGU_PERI, CGU_I2SOUT_APB_CLOCK_ENABLE);
-    CGU_AUDIO |= (1<<11);
-
     dma_retain();
 
-    is_playing = true;
-
     /* force writeback */
     clean_dcache_range(dma_start_addr, dma_start_size);
+
+    bitset32(&CGU_AUDIO, (1<<11));
+
     play_start_pcm();
 }
 
 void pcm_play_dma_stop(void)
 {
     is_playing = false;
+
     dma_disable_channel(1);
 
     /* Ensure byte counts read back 0 */
@@ -146,8 +152,10 @@ void pcm_play_dma_stop(void)
 
     dma_release();
 
-    bitclr32(&CGU_PERI, CGU_I2SOUT_APB_CLOCK_ENABLE);
-    CGU_AUDIO &= ~(1<<11);
+#ifdef HAVE_RECORDING
+    if (!is_recording)
+        bitclr32(&CGU_AUDIO, (1<<11));
+#endif
 
     play_callback_pending = false;
 }
@@ -175,10 +183,10 @@ void pcm_play_dma_pause(bool pause)
 void pcm_play_dma_init(void)
 {
     bitset32(&CGU_PERI, CGU_I2SOUT_APB_CLOCK_ENABLE);
-
-    I2SOUT_CONTROL = (1<<6)|(1<<3)  /* enable dma, stereo */;
+    I2SOUT_CONTROL = (1<<6) | (1<<3);  /* enable dma, stereo */
 
     audiohw_preinit();
+    pcm_dma_apply_settings();
 }
 
 void pcm_play_dma_postinit(void)
@@ -209,14 +217,15 @@ static inline unsigned char mclk_divider(void)
 
 void pcm_dma_apply_settings(void)
 {
-    int cgu_audio = CGU_AUDIO;              /* read register */
-    cgu_audio &= ~(3 << 0);                 /* clear i2sout MCLK_SEL */
-    cgu_audio |=  (AS3525_MCLK_SEL << 0);   /* set i2sout MCLK_SEL */
-    cgu_audio &= ~(0x1ff << 2);             /* clear i2sout divider */
-    cgu_audio |= mclk_divider() << 2;       /* set new i2sout divider */
-    cgu_audio &= ~(1 << 23);                /* clear I2SI_MCLK_EN */
-    cgu_audio &= ~(1 << 24);                /* clear I2SI_MCLK2PAD_EN */
-    CGU_AUDIO = cgu_audio;                  /* write back register */
+    bitmod32(&CGU_AUDIO,
+             (0<<24) |               /* I2SI_MCLK2PAD_EN = disabled */
+             (0<<23) |               /* I2SI_MCLK_EN = disabled */
+             (0<<14) |               /* I2SI_MCLK_DIV_SEL = unused */
+             (0<<12) |               /* I2SI_MCLK_SEL = clk_main */
+                                     /* I2SO_MCLK_EN = unchanged */
+             (mclk_divider() << 2) | /* I2SO_MCLK_DIV_SEL */
+             (AS3525_MCLK_SEL << 0), /* I2SO_MCLK_SEL */
+             0x01fff7ff);
 }
 
 size_t pcm_get_bytes_waiting(void)
@@ -258,220 +267,158 @@ void * pcm_dma_addr(void *addr)
 #ifdef HAVE_RECORDING
 
 static int rec_locked = 0;
-static bool is_recording = false;
-static bool rec_callback_pending = false;
-static void *rec_dma_start_addr;
-static size_t rec_dma_size, rec_dma_transfer_size;
-static void rec_dma_callback(void);
-#if CONFIG_CPU == AS3525
-/* points to the samples which need to be duplicated into the right channel */
-static int16_t *mono_samples;
-#endif
-
+static uint32_t *rec_dma_addr;
+static size_t rec_dma_size;
 
 void pcm_rec_lock(void)
 {
-    ++rec_locked;
-}
-
+    int oldlevel = disable_irq_save();
 
-void pcm_rec_unlock(void)
-{
-    if(--rec_locked == 0 && is_recording)
+    if (++rec_locked == 1)
     {
-        int old = disable_irq_save();
-        if(rec_callback_pending)
-        {
-            rec_callback_pending = false;
-            rec_dma_callback();
-        }
-        restore_irq(old);
+        bitset32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE);
+        VIC_INT_EN_CLEAR = INTERRUPT_I2SIN;
+        I2SIN_MASK = 0; /* disables all interrupts */
     }
-}
-
 
-static void rec_dma_start(void)
-{
-    rec_dma_transfer_size = rec_dma_size;
-
-    /* We are limited to 8188 DMA transfers, and the recording core asks for
-     * 8192 bytes. Avoid splitting 8192 bytes transfers in 8188 + 4 */
-    if(rec_dma_transfer_size > 4096)
-        rec_dma_transfer_size = 4096;
-
-    dma_enable_channel(1, (void*)I2SIN_DATA, rec_dma_start_addr, DMA_PERI_I2SIN,
-                DMAC_FLOWCTRL_DMAC_PERI_TO_MEM, false, true,
-                rec_dma_transfer_size >> 2, DMA_S4, rec_dma_callback);
+    restore_irq(oldlevel);
 }
 
 
-#if CONFIG_CPU == AS3525
-/* if needed, duplicate samples of the working channel until the given bound */
-static inline void mono2stereo(int16_t *end)
-{
-    if(audio_channels != 1) /* only for microphone */
-        return;
-#if 0
-    /* load pointer in a register and avoid updating it in each loop */
-    register int16_t *samples = mono_samples;
-
-    do {
-        int16_t left = *samples++;  // load 1 sample of the left-channel
-        *samples++ = left;          // copy it in the right-channel
-    } while(samples != end);
-
-    mono_samples = samples; /* update pointer */
-#else
-    /* gcc doesn't use pre indexing : let's save 1 cycle */
-    int16_t left;
-    asm (
-        "1: ldrh %0, [%1], #2   \n" // load 1 sample of the left-channel
-        "   strh %0, [%1], #2   \n" // copy it in the right-channel
-        "   cmp %1, %2          \n" // are we finished?
-        "   bne  1b             \n"
-        : "=&r"(left), "+r"(mono_samples)
-        : "r"(end)
-        : "memory"
-    );
-#endif /* C / ASM */
-}
-#endif /* CONFIG_CPU == AS3525 */
-
-#if CONFIG_CPU == AS3525v2
-/* scale microphone audio by 2 bits due to 14 bit ADC */
-static inline void scalevolume(int16_t *end, int size)
+void pcm_rec_unlock(void)
 {
-    if(audio_channels != 1) /* only for microphone */
-        return;
-
-    /* load pointer in a register and avoid updating it in each loop */
-    register int16_t *samples = end;
-
-    do {
-        *samples++ <<=2;  
-
-    } while(samples != end+size);
-
-}
-#endif /* CONFIG_CPU == AS3525v2 */
+    int oldlevel = disable_irq_save();
 
-static void rec_dma_callback(void)
-{
-    if(rec_dma_transfer_size)
+    if (--rec_locked == 0 && is_recording)
     {
+        VIC_INT_ENABLE = INTERRUPT_I2SIN;
+        I2SIN_MASK = (1<<2); /* I2SIN_MASK_POAF */
+    }
 
-#if CONFIG_CPU == AS3525v2
-        scalevolume(AS3525_UNCACHED_ADDR((int16_t*)rec_dma_start_addr), rec_dma_transfer_size);
-#endif
-        rec_dma_size -= rec_dma_transfer_size;
-        rec_dma_start_addr += rec_dma_transfer_size;
+    restore_irq(oldlevel);
+}
 
-        /* don't act like we just transferred data when we are called from
-         * pcm_rec_unlock() */
-        rec_dma_transfer_size = 0;
 
+void INT_I2SIN(void)
+{
 #if CONFIG_CPU == AS3525
-        /* the 2nd channel is silent when recording microphone on as3525v1 */
-        mono2stereo(AS3525_UNCACHED_ADDR((int16_t*)rec_dma_start_addr));
-#endif
-
-        if(locked)
+    if (audio_channels == 1)
+    {
+        /* RX is left-channel-only mono */
+        while (rec_dma_size > 0)
         {
-            rec_callback_pending = is_recording;
-            return;
+            if (I2SIN_RAW_STATUS & (1<<5))
+                return; /* empty */
+
+            /* Discard every other sample since ADC clock is 1/2 LRCK */
+            uint32_t value = *I2SIN_DATA;
+            *I2SIN_DATA;
+
+            /* Data is in left channel only - copy to right channel
+               14-bit => 16-bit samples */
+            value = (uint16_t)(value << 2) | (value << 18);
+
+            if (audio_output_source != AUDIO_SRC_PLAYBACK && !is_playing)
+            {
+                /* In this case, loopback is manual so that both output
+                   channels have audio */
+                if (I2SOUT_RAW_STATUS & (1<<5))
+                {
+                    /* Sync output fifo so it goes empty not before input is
+                       filled */
+                    for (unsigned i = 0; i < 4; i++)
+                        *I2SOUT_DATA = 0;
+                }
+
+                *I2SOUT_DATA = value;
+                *I2SOUT_DATA = value;
+            }
+
+            *rec_dma_addr++ = value;
+            rec_dma_size -= 4;
         }
     }
-
-    if(!rec_dma_size)
+    else
+#endif /* CONFIG_CPU == AS3525 */
     {
-        pcm_rec_more_ready_callback(0, &rec_dma_start_addr,
-                                    &rec_dma_size);
+        /* RX is stereo */
+        while (rec_dma_size > 0)
+        {
+            if (I2SIN_RAW_STATUS & (1<<5))
+                return; /* empty */
 
-        if(rec_dma_size == 0)
-            return;
+            /* Discard every other sample since ADC clock is 1/2 LRCK */
+            uint32_t value = *I2SIN_DATA;
+            *I2SIN_DATA;
 
-        dump_dcache_range(rec_dma_start_addr, rec_dma_size);
-#if CONFIG_CPU == AS3525
-        mono_samples = AS3525_UNCACHED_ADDR((int16_t*)rec_dma_start_addr);
-#endif
+            /* Loopback is in I2S hardware */
+
+            /* 14-bit => 16-bit samples */
+            *rec_dma_addr++ = (value << 2) & ~0x00030000;
+            rec_dma_size -= 4;
+        }
     }
 
-    rec_dma_start();
+    pcm_rec_more_ready_callback(0, (void *)&rec_dma_addr, &rec_dma_size);
 }
 
+
 void pcm_rec_dma_stop(void)
 {
     is_recording = false;
-    dma_disable_channel(1);
-    dma_release();
-    rec_dma_size = 0;
 
-    I2SIN_CONTROL &= ~(1<<11); /* disable dma */
+    VIC_INT_EN_CLEAR = INTERRUPT_I2SIN;
+    I2SIN_MASK = 0; /* disables all interrupts */
+
+    rec_dma_addr = NULL;
+    rec_dma_size = 0;
 
-    CGU_AUDIO &= ~(1<<11);
-    bitclr32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE |
-                        CGU_I2SOUT_APB_CLOCK_ENABLE);
+    if (!is_playing)
+        bitclr32(&CGU_AUDIO, (1<<11));
 
-    rec_callback_pending = false;
+    bitclr32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE);
 }
 
 
 void pcm_rec_dma_start(void *addr, size_t size)
 {
-    dump_dcache_range(addr, size);
-    rec_dma_start_addr = addr;
-#if CONFIG_CPU == AS3525
-    mono_samples = AS3525_UNCACHED_ADDR(addr);
-#endif
-    rec_dma_size = size;
-
-    dma_retain();
+    is_recording = true;
 
-    bitset32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE |
-                        CGU_I2SOUT_APB_CLOCK_ENABLE);
-    CGU_AUDIO |= (1<<11);
+    bitset32(&CGU_AUDIO, (1<<11));
 
-    I2SIN_CONTROL |= (1<<11)|(1<<5); /* enable dma, 14bits samples */
+    rec_dma_addr = addr;
+    rec_dma_size = size;
 
-    is_recording = true;
+    /* ensure empty FIFO */
+    while (!(I2SIN_RAW_STATUS & (1<<5)))
+        *I2SIN_DATA;
 
-    rec_dma_start();
+    I2SIN_CLEAR = (1<<6) | (1<<0); /* push error, pop error */
 }
 
 
 void pcm_rec_dma_close(void)
 {
+    bitset32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE);
+    pcm_rec_dma_stop();
 }
 
 
 void pcm_rec_dma_init(void)
 {
-    /* i2c clk src = I2SOUTIF, sdata src = AFE,
-     * data valid at positive edge of SCLK */
-    I2SIN_CONTROL = (1<<2);
+    bitset32(&CGU_PERI, CGU_I2SIN_APB_CLOCK_ENABLE);
+
     I2SIN_MASK = 0; /* disables all interrupts */
+
+    /* 14 bits samples, i2c clk src = I2SOUTIF, sdata src = AFE,
+     * data valid at positive edge of SCLK */
+    I2SIN_CONTROL = (1<<5) | (1<<2);
 }
 
 
 const void * pcm_rec_dma_get_peak_buffer(void)
 {
-#if CONFIG_CPU == AS3525
-    /*
-     * We need to prevent the DMA callback from kicking in while we are
-     * faking the right channel with data from left channel.
-     */
-
-    int old = disable_irq_save();
-    int16_t *addr = AS3525_UNCACHED_ADDR((int16_t *)DMAC_CH_DST_ADDR(1));
-    mono2stereo(addr);
-    restore_irq(old);
-
-    return addr;
-
-#else
-    /* Microphone recording is stereo on as3525v2 */
-    return AS3525_UNCACHED_ADDR((int16_t *)DMAC_CH_DST_ADDR(1));
-#endif
+    return rec_dma_addr;
 }
 
 #endif /* HAVE_RECORDING */
diff --git a/firmware/target/arm/sandisk/audio-c200_e200.c b/firmware/target/arm/sandisk/audio-c200_e200.c
index 2f6bde1b98..4de7aa62c3 100644
--- a/firmware/target/arm/sandisk/audio-c200_e200.c
+++ b/firmware/target/arm/sandisk/audio-c200_e200.c
@@ -186,16 +186,25 @@ void audiohw_set_sampr_dividers(int fsel)
     IISDIV = (IISDIV & ~0xc000003f) | regvals[fsel].iisdiv;
 }
 
-#ifdef HAVE_RECORDING
-unsigned int pcm_sampr_type_rec_to_play(unsigned int samplerate)
+#ifdef CONFIG_SAMPR_TYPES
+unsigned int pcm_sampr_to_hw_sampr(unsigned int samplerate,
+                                   unsigned int type)
 {
-    /* Check if the samplerate is in the list of recordable rates.
-     * Fail to default if not */
-    int index = round_value_to_list32(samplerate, rec_freq_sampr,
-                                      REC_NUM_FREQ, false);
-    if (samplerate != rec_freq_sampr[index])
-        return HW_SAMPR_DEFAULT;
-
-    return samplerate * 2; /* Recording rates are 1/2 the codec clock */
+#ifdef HAVE_RECORDING
+    if (samplerate != HW_SAMPR_RESET && type == SAMPR_TYPE_REC)
+    {
+        /* Check if the samplerate is in the list of recordable rates.
+         * Fail to default if not */
+        int index = round_value_to_list32(samplerate, rec_freq_sampr,
+                                          REC_NUM_FREQ, false);
+        if (samplerate != rec_freq_sampr[index])
+            samplerate = REC_SAMPR_DEFAULT;
+
+        samplerate *= 2; /* Recording rates are 1/2 the codec clock */
+    }
+#endif /* HAVE_RECORDING */
+
+    return samplerate;
+    (void)type;
 }
-#endif
+#endif /* CONFIG_SAMPR_TYPES */