AMS: Return ascodec to interrupt-based I2C2 driver

1. Slightly revised and regularized internal interface. Callback is used
for read and write to provide completion signal instead of having two
mechanisms.

2. Lower overhead for asynchronous or alterate completion callbacks. We
now only init what is required by the transfer. A couple unneeded
structure members were also nixed.

3. Fixes a bug that would neglect a semaphore wait if pumping the I2C
interrupts in a loop when not in thread state or interrupts are masked.

4. Corrects broken initialization order by defining KDEV_INIT, which
makes kernel_init() call kernel_device_init() to initialize additional
devices _after_ the kernel, threading and synchronization objects are
safe to use.

5. Locking set_cpu_frequency has to be done at the highest level in
system.c to ensure the boost counter and the frequency are both set in
agreement. Reconcile the locking inteface between PP and AMS (the only
two currently using locking there) to keep it clean.

Now works fine with voltages in GIT HEAD on my Fuze v2, type 0.
Previously, everything crashed and died instantly. action.c calling
set_cpu_frequency from a tick was part of it. The rest may have been
related to 3. and 4. Honestly, I'm not certain!

Testing by Mihail Zenkov indicates it solves our problems. This will
get the developer builds running again after the kernel assert code
push.

Change-Id: Ie245994fb3e318dd5ef48e383ce61fdd977224d4

1 files changed, 13 insertions, 16 deletions

diff --git a/firmware/system.c b/firmware/system.c
index 37631b8735..537e901b05 100644
--- a/firmware/system.c
+++ b/firmware/system.c
@@ -35,13 +35,6 @@ long cpu_frequency SHAREDBSS_ATTR = CPU_FREQ;
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 static int boost_counter SHAREDBSS_ATTR = 0;
 static bool cpu_idle SHAREDBSS_ATTR = false;
-#if NUM_CORES > 1
-static struct corelock boostctrl_cl SHAREDBSS_ATTR;
-void cpu_boost_init(void)
-{
-    corelock_init(&boostctrl_cl);
-}
-#endif
 
 int get_cpu_boost_counter(void)
 {
@@ -60,7 +53,7 @@ int cpu_boost_log_getcount(void)
 char * cpu_boost_log_getlog_first(void)
 {
     char *first;
-    corelock_lock(&boostctrl_cl);
+    cpu_boost_lock();
 
     first = NULL;
 
@@ -70,7 +63,7 @@ char * cpu_boost_log_getlog_first(void)
         first = cpu_boost_calls[cpu_boost_first];
     }
 
-    corelock_unlock(&boostctrl_cl);
+    cpu_boost_unlock();
     return first;
 }
 
@@ -79,7 +72,7 @@ char * cpu_boost_log_getlog_next(void)
     int message;
     char *next;
 
-    corelock_lock(&boostctrl_cl);
+    cpu_boost_lock();
 
     message = (cpu_boost_track_message+cpu_boost_first)%MAX_BOOST_LOG;
     next = NULL;
@@ -90,13 +83,14 @@ char * cpu_boost_log_getlog_next(void)
         next = cpu_boost_calls[message];
     }
 
-    corelock_unlock(&boostctrl_cl);
+    cpu_boost_unlock();
     return next;
 }
 
 void cpu_boost_(bool on_off, char* location, int line)
 {
-    corelock_lock(&boostctrl_cl);
+    if (!cpu_boost_lock())
+        return;
 
     if (cpu_boost_calls_count == MAX_BOOST_LOG)
     {
@@ -115,7 +109,9 @@ void cpu_boost_(bool on_off, char* location, int line)
 #else
 void cpu_boost(bool on_off)
 {
-    corelock_lock(&boostctrl_cl);
+    if (!cpu_boost_lock())
+        return;
+
 #endif /* CPU_BOOST_LOGGING */
     if(on_off)
     {
@@ -141,12 +137,13 @@ void cpu_boost(bool on_off)
         }
     }
 
-    corelock_unlock(&boostctrl_cl);
+    cpu_boost_unlock();
 }
 
 void cpu_idle_mode(bool on_off)
 {
-    corelock_lock(&boostctrl_cl);
+    if (!cpu_boost_lock())
+        return;
 
     cpu_idle = on_off;
 
@@ -160,7 +157,7 @@ void cpu_idle_mode(bool on_off)
             set_cpu_frequency(CPUFREQ_NORMAL);
     }
 
-    corelock_unlock(&boostctrl_cl);
+    cpu_boost_unlock();
 }
 #endif /* HAVE_ADJUSTABLE_CPU_FREQ */