imx233/fuze+: implement lradc function and adc on top of it

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30534 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 62 insertions, 2 deletions

diff --git a/firmware/target/arm/imx233/adc-imx233.c b/firmware/target/arm/imx233/adc-imx233.c
index 8236f58767..4f183ac531 100644
--- a/firmware/target/arm/imx233/adc-imx233.c
+++ b/firmware/target/arm/imx233/adc-imx233.c
@@ -23,12 +23,72 @@
 #include "adc.h"
 #include "adc-target.h"
 
+/* dedicate two channels to temperature sensing
+ * dedicate channel 7 to battery
+ * and channel 6 to vddio */
+static int pmos_chan, nmos_chan;
+static int battery_chan, vddio_chan;
+
 void adc_init(void)
 {
+    imx233_lradc_init();
+    battery_chan = 7;
+    imx233_lradc_reserve_channel(7);
+    vddio_chan = 6;
+    imx233_lradc_reserve_channel(6);
+    
+    pmos_chan = imx233_lradc_acquire_channel(0);
+    if(pmos_chan < 0) panicf("No LRADC channel for PMOS !");
+    nmos_chan = imx233_lradc_acquire_channel(0);
+    if(nmos_chan < 0) panicf("No LRADC channel for NMOS !");
+
+    // setup them
+    imx233_lradc_setup_channel(battery_chan, false, false, 0, HW_LRADC_CHANNEL_BATTERY);
+    imx233_lradc_setup_channel(vddio_chan, false, false, 0, HW_LRADC_CHANNEL_VDDIO);
+    imx233_lradc_setup_channel(nmos_chan, false, false, 0, HW_LRADC_CHANNEL_NMOS_THIN);
+    imx233_lradc_setup_channel(pmos_chan, false, false, 0, HW_LRADC_CHANNEL_PMOS_THIN);
+}
+
+int adc_read_physical_ex(int virt)
+{
+    imx233_lradc_clear_channel(virt);
+    imx233_lradc_kick_channel(virt);
+    imx233_lradc_wait_channel(virt);
+    int v = imx233_lradc_read_channel(virt);
+    return v;
+}
+
+int adc_read_physical(int src)
+{
+    int virt = imx233_lradc_acquire_channel(TIMEOUT_BLOCK);
+    // divide by two for wider ranger
+    imx233_lradc_setup_channel(virt, false, false, 0, src);
+    int val = adc_read_physical_ex(virt);
+    imx233_lradc_release_channel(virt);
+    return val;
+}
+
+unsigned short adc_read_virtual(int c)
+{
+    switch(c)
+    {
+        case IMX233_ADC_BATTERY:
+            return adc_read_physical_ex(battery_chan);
+        case IMX233_ADC_VDDIO:
+            return adc_read_physical_ex(vddio_chan);
+        case IMX233_ADC_DIE_TEMP:
+            // do kelvin to celsius conversion
+            return imx233_lradc_sense_die_temperature(nmos_chan, pmos_chan) - 273;
+        default:
+            return 0;
+    }
 }
 
 unsigned short adc_read(int channel)
 {
-    (void) channel;
-    return 0;
+    int c = imx233_adc_mapping[channel];
+    if(c < 0)
+        return adc_read_virtual(c);
+    else
+        return adc_read_physical(c);
 }