Stop reading buttons if one is not down. Don't read remote keys if not plugged. Good for another few points of boost and 4fps full-screen unboosted. The button scan enabling seems stable and I've been using it without any difficulties but if the interrupts hiccup it could leave them unresponsive. Clearing the GPI0 interrupts before enabling them seems to prevent any difficulties. If there's problems there I'll just leave the remote reading bypass only and 50% of the benefits will still be realized.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11357 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 36 insertions, 8 deletions

diff --git a/firmware/target/coldfire/iaudio/x5/adc-x5.c b/firmware/target/coldfire/iaudio/x5/adc-x5.c
index fc45da8624..c923951e31 100755
--- a/firmware/target/coldfire/iaudio/x5/adc-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/adc-x5.c
@@ -26,19 +26,47 @@
 
 static unsigned short adcdata[NUM_ADC_CHANNELS];
 
-static int channelnum[] =
+static const int adcc2_parms[] =
 {
-    5,   /* ADC_BUTTONS (ADCIN2) */
-    6,   /* ADC_REMOTE  (ADCIN3) */
-    0,   /* ADC_BATTERY (BATVOLT, resistive divider) */
+    [ADC_BUTTONS] = 0x80 | (5 << 1) | 1, /* ADCIN2 */
+    [ADC_REMOTE]  = 0x80 | (6 << 1) | 1, /* ADCIN3 */
+    [ADC_BATTERY] = 0x80 | (0 << 1) | 1, /* BATVOLT, resistive divider */
 };
 
+/* have buttons scan by default */
+static volatile bool button_scan_on = true;
+
+void adc_enable_button_scan(bool enable)
+{
+    button_scan_on = enable;
+}
+
+bool adc_get_button_scan_enabled(void)
+{
+    return button_scan_on;
+}
+
 unsigned short adc_scan(int channel)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level;
     unsigned char data;
-    
-    pcf50606_write(0x2f, 0x80 | (channelnum[channel] << 1) | 1);
+
+    if (channel == ADC_BUTTONS)
+    {
+        /* no button scan if nothing pushed */
+        if (!button_scan_on)
+            return adcdata[channel] = 0xff;
+    }
+    else if (channel == ADC_REMOTE)
+    {
+        /* no remote scan if not plugged */
+        if (GPIO_READ & 0x01000000)
+            return adcdata[channel] = 0xff;
+    }
+
+    level = set_irq_level(HIGHEST_IRQ_LEVEL);
+
+    pcf50606_write(0x2f, adcc2_parms[channel]);
     data = pcf50606_read(0x30);
 
     adcdata[channel] = data;
@@ -56,7 +84,7 @@ static int adc_counter;
 
 static void adc_tick(void)
 {
-    if(++adc_counter == HZ)
+    if (++adc_counter == HZ)
     {
         adc_counter = 0;
         adc_scan(ADC_BATTERY);