as3525: reverting I2C2 to non-interrupts version

Interrupts version is cause of freeze on USB extraction.
Also non-interrupts version much simpler and faster.

Change-Id: I30a2993cdcaa85abfba77ca06bfacd5b6b4353e2

1 files changed, 5 insertions, 27 deletions

diff --git a/firmware/drivers/adc-as3514.c b/firmware/drivers/adc-as3514.c
index 8c661eb..3b411a3 100644
--- a/firmware/drivers/adc-as3514.c
+++ b/firmware/drivers/adc-as3514.c
@@ -26,40 +26,18 @@
 /* Read 10-bit channel data */
 unsigned short adc_read(int channel)
 {
-    unsigned short data = 0;
-
-    if ((unsigned)channel >= NUM_ADC_CHANNELS)
-        return 0;
+    unsigned char buf[2];
 
     ascodec_lock();
 
     /* Select channel */
-    if (ascodec_write(AS3514_ADC_0, (channel << 4)) >= 0)
-    {
-        unsigned char buf[2];
-
-        /*
-         * The AS3514 ADC will trigger an interrupt when the conversion
-         * is finished, if the corresponding enable bit in IRQ_ENRD2
-         * is set.
-         * Previously the code did not wait and this apparently did
-         * not pose any problems, but this should be more correct.
-         * Without the wait the data read back may be completely or
-         * partially (first one of the two bytes) stale.
-         */
-        ascodec_wait_adc_finished();
+    ascodec_write(AS3514_ADC_0, (channel << 4));
 
-
-        /* Read data */
-        if (ascodec_readbytes(AS3514_ADC_0, 2, buf) >= 0)
-        {
-            data = (((buf[0] & 0x3) << 8) | buf[1]);
-        }
-    }
+    ascodec_readbytes(AS3514_ADC_0, 2, buf);
 
     ascodec_unlock();
-    
-    return data;
+
+    return (((buf[0] & 0x3) << 8) | buf[1]);
 }
 
 void adc_init(void)