libaudio: Improve FM Radio

- Set the volume control of the Si4709 chip (I891574d6 originally
  did this)

- Set the playback path to HP, HP_NO_MIC, SPK as appropriate
  (allows WM8994 to apply its analog gain)

- Turn off FM Radio properly to allow WM8994 to be turned off after
  disabling FM Radio (fixes battery drain and routing problems which
  caused FM Radio to be mute if you listen to FM, listen to music and
  listen to FM again.)

Change-Id: Id04aaddc6de5ffe1c0826bea33fc8ec633afd419

2 files changed, 60 insertions, 7 deletions

diff --git a/libaudio/AudioHardware.cpp b/libaudio/AudioHardware.cpp
index 939c54c..c2efbd1 100644
--- a/libaudio/AudioHardware.cpp
+++ b/libaudio/AudioHardware.cpp
@@ -40,6 +40,10 @@ extern "C" {
 #include "alsa_audio.h"
 }
 
+#ifdef HAVE_FM_RADIO
+#define Si4709_IOC_MAGIC  0xFA
+#define Si4709_IOC_VOLUME_SET                       _IOW(Si4709_IOC_MAGIC, 15, __u8)
+#endif
 
 namespace android {
 
@@ -92,6 +96,9 @@ AudioHardware::AudioHardware() :
     mSecRilLibHandle(NULL),
     mRilClient(0),
     mActivatedCP(false),
+#ifdef HAVE_FM_RADIO
+    mFmFd(-1),
+#endif
     mDriverOp(DRV_NONE)
 {
     loadRILD();
@@ -523,6 +530,10 @@ status_t AudioHardware::setParameters(const String8& keyValuePairs)
             LOGV("AudioHardware::setParameters() FM Radio is ON, calling setFMRadioPath_l()");
             setFMRadioPath_l(mOutput->device());
         }
+
+        if (mFmFd < 0) {
+            mFmFd = open("/dev/radio0", O_RDWR);
+        }
     }
     param.remove(key);
 
@@ -532,22 +543,27 @@ status_t AudioHardware::setParameters(const String8& keyValuePairs)
         LOGV("AudioHardware::setParameters() Turning FM Radio OFF");
 
         if (mMixer != NULL) {
+            // Disable FM radio flag to allow the codec to be turned off
+            // (the flag is automatically set by the kernel driver when FM is enabled)
+            // No need to turn off the FM Radio path as the kernel driver will handle that
             TRACE_DRIVER_IN(DRV_MIXER_GET)
-            struct mixer_ctl *ctl= mixer_get_control(mMixer, "FM Radio Path", 0);
+            struct mixer_ctl *ctl = mixer_get_control(mMixer, "Codec Status", 0);
             TRACE_DRIVER_OUT
 
             if (ctl != NULL) {
                 TRACE_DRIVER_IN(DRV_MIXER_SEL)
-                mixer_ctl_select(ctl, "FMR_MIX_OFF");
-                TRACE_DRIVER_OUT
-
-                TRACE_DRIVER_IN(DRV_MIXER_SEL)
-                mixer_ctl_select(ctl, "FMR_OFF");
+                mixer_ctl_select(ctl, "FMR_FLAG_CLEAR");
                 TRACE_DRIVER_OUT
             }
+
             closeMixer_l();
             closePcmOut_l();
         }
+
+        if (mFmFd > 0) {
+            close(mFmFd);
+            mFmFd = -1;
+        }
     }
     param.remove(key);
 #endif
@@ -645,6 +661,21 @@ status_t AudioHardware::setMasterVolume(float volume)
     return -1;
 }
 
+#ifdef HAVE_FM_RADIO
+status_t AudioHardware::setFmVolume(float v)
+{
+    if (mFmFd > 0) {
+        __u8 fmVolume = (AudioSystem::logToLinear(v) + 5) / 7;
+        LOGD("%s %f %d", __func__, v, (int) fmVolume);
+        if (ioctl(mFmFd, Si4709_IOC_VOLUME_SET, &fmVolume) < 0) {
+            LOGE("set_volume_fm error.");
+            return -EIO;
+        }
+    }
+    return NO_ERROR;
+}
+#endif
+
 static const int kDumpLockRetries = 50;
 static const int kDumpLockSleep = 20000;
 
@@ -828,7 +859,22 @@ status_t AudioHardware::setFMRadioPath_l(uint32_t device)
             mixer_ctl_select(ctl, fmpath);
             TRACE_DRIVER_OUT
         } else {
-            LOGE("setFMRadioPath_l() could not get mixer ctl");
+            LOGE("setFMRadioPath_l() could not get FM Radio Path mixer ctl");
+        }
+
+        TRACE_DRIVER_IN(DRV_MIXER_GET)
+        ctl = mixer_get_control(mMixer, "Playback Path", 0);
+        TRACE_DRIVER_OUT
+
+        const char *route = getOutputRouteFromDevice(device);
+        LOGV("setFMRadioPath_l() Playpack Path, (%s)", route);
+        if (ctl) {
+            TRACE_DRIVER_IN(DRV_MIXER_SEL)
+            mixer_ctl_select(ctl, route);
+            TRACE_DRIVER_OUT
+        }
+        else {
+            LOGE("setFMRadioPath_l() could not get Playback Path mixer ctl");
         }
     } else {
         LOGE("setFMRadioPath_l() mixer is not open");
diff --git a/libaudio/AudioHardware.h b/libaudio/AudioHardware.h
index 71f11e7..b50e273 100644
--- a/libaudio/AudioHardware.h
+++ b/libaudio/AudioHardware.h
@@ -86,6 +86,9 @@ public:
 
     virtual status_t setVoiceVolume(float volume);
     virtual status_t setMasterVolume(float volume);
+#ifdef HAVE_FM_RADIO
+    virtual status_t setFmVolume(float volume);
+#endif
 
     virtual status_t setMode(int mode);
 
@@ -177,6 +180,10 @@ private:
     void            loadRILD(void);
     status_t        connectRILDIfRequired(void);
 
+#ifdef HAVE_FM_RADIO
+    int             mFmFd;
+#endif
+
     //  trace driver operations for dump
     int             mDriverOp;