iPod Classic: capture support for CS42L55 codec

There are a couple of power saving options that can be selected using
defines, they configure the CODEC in a different way than OF does:

 MONO_MIC: jack microphone is connected to left channel, disabling
 right channel saves ~1 mW, there is no reason to not to do it.

 BYPASS_PGA: this option only applies to the line-in, OF does not
 bypass the PGA and configures it to 0 dB gain. At the beginning,
 this patch was written based on CODEC datasheet, bypassing PGA
 because it saves power and incrementes dinamic range ~1dB, i have
 used this setup for a while without problems. Finally this option
 was disabled at the last minute, i decided to do it after reviewing
 the OF and realizing that CS42L55 datasheet recommends to bypass the
 PGA only if the HW includes a couple of capacitors (see Typical
 Connection Diagram, Note 4), at this moment i don't know if Classic
 includes these capacitors (probably not). Anyway, i am not able to
 tell the difference listening to voice recodings.

TODO:
- Use variable PGA gain for jack microphone (it is fixed to +12 dB.
  as OF does).
- I am not a fan of having lots of unused #define options, these could
  be useful for a generic driver but actually this driver is Classic
  oriented, i am not sure if it could be considered disirable to
  eliminate them in the final version.

Change-Id: I3dadf2341f44d5e13f3847e6c9de4a76cd6f0918

1 files changed, 12 insertions, 1 deletions

diff --git a/firmware/export/cs42l55.h b/firmware/export/cs42l55.h
index d8d177e..11ceb9b 100644
--- a/firmware/export/cs42l55.h
+++ b/firmware/export/cs42l55.h
@@ -23,13 +23,24 @@
 #define __CS42L55_H__
 
 #define AUDIOHW_CAPS (BASS_CAP | TREBLE_CAP | BASS_CUTOFF_CAP | \
-                      TREBLE_CUTOFF_CAP | PRESCALER_CAP | LINEOUT_CAP)
+                      TREBLE_CUTOFF_CAP | PRESCALER_CAP | LINEOUT_CAP | \
+                      LIN_GAIN_CAP | MIC_GAIN_CAP)
 
 AUDIOHW_SETTING(VOLUME,       "dB", 0,  1, -60,  12, -25)
 AUDIOHW_SETTING(BASS,         "dB", 1, 15,-105, 120,   0)
 AUDIOHW_SETTING(TREBLE,       "dB", 1, 15,-105, 120,   0)
 AUDIOHW_SETTING(BASS_CUTOFF,    "", 0,  1,   1,   4,   2)
 AUDIOHW_SETTING(TREBLE_CUTOFF,  "", 0,  1,   1,   4,   1)
+#ifdef HAVE_RECORDING
+#define PGA_GAIN_DB     12  /* PGA fixed gain, range: -6 to +12 dB */
+AUDIOHW_SETTING(LEFT_GAIN,    "dB", 0,  1, -96,   0,   0)
+AUDIOHW_SETTING(RIGHT_GAIN,   "dB", 0,  1, -96,   0,   0)
+AUDIOHW_SETTING(MIC_GAIN,     "dB", 0,  1, -96,   0,   0, val + PGA_GAIN_DB)
+#endif /* HAVE_RECORDING */
+
+/* powered DSP modules */
+#define DSP_MODULE_TONE         (1 << 0)
+#define DSP_MODULE_MONITOR      (1 << 1)
 
 void audiohw_enable_lineout(bool enable);