1 files changed, 75 insertions, 0 deletions

diff --git a/firmware/target/arm/imx233/lradc-imx233.c b/firmware/target/arm/imx233/lradc-imx233.c
index 432d1c1035..4d309b0875 100644
--- a/firmware/target/arm/imx233/lradc-imx233.c
+++ b/firmware/target/arm/imx233/lradc-imx233.c
@@ -27,6 +27,9 @@
 static struct channel_arbiter_t channel_arbiter;
 /* delay channels */
 static struct channel_arbiter_t delay_arbiter;
+/* battery is very special, dedicate a channel and a delay to it */
+static int battery_chan;
+static int battery_delay_chan;
 
 void imx233_lradc_setup_channel(int channel, bool div2, bool acc, int nr_samples, int src)
 {
@@ -111,6 +114,8 @@ void imx233_lradc_reserve_delay(int channel)
 
 int imx233_lradc_sense_die_temperature(int nmos_chan, int pmos_chan)
 {
+    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);
     // mux sensors
     __REG_CLR(HW_LRADC_CTRL2) = HW_LRADC_CTRL2__TEMPSENSE_PWD;
     imx233_lradc_clear_channel(nmos_chan);
@@ -129,6 +134,60 @@ int imx233_lradc_sense_die_temperature(int nmos_chan, int pmos_chan)
     return (diff * 1012) / 4000;
 }
 
+/* set to 0 to disable current source */
+static void imx233_lradc_set_temp_isrc(int sensor, int value)
+{
+    if(sensor < 0 || sensor > 1)
+        panicf("imx233_lradc_set_temp_isrc: invalid sensor");
+    unsigned mask = HW_LRADC_CTRL2__TEMP_ISRCx_BM(sensor);
+    unsigned bp = HW_LRADC_CTRL2__TEMP_ISRCx_BP(sensor);
+    unsigned en = HW_LRADC_CTRL2__TEMP_SENSOR_IENABLEx(sensor);
+
+    __REG_CLR(HW_LRADC_CTRL2) = mask;
+    __REG_SET(HW_LRADC_CTRL2) = value << bp;
+    if(value != 0)
+    {
+        __REG_SET(HW_LRADC_CTRL2) = en;
+        udelay(100);
+    }
+    else
+        __REG_CLR(HW_LRADC_CTRL2) = en;
+}
+
+int imx233_lradc_sense_ext_temperature(int chan, int sensor)
+{
+#define EXT_TEMP_ACC_COUNT  5
+    /* setup channel */
+    imx233_lradc_setup_channel(chan, false, false, 0, sensor);
+    /* set current source to 300µA */
+    imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__300uA);
+    /* read value and accumulate */
+    int a = 0;
+    for(int i = 0; i < EXT_TEMP_ACC_COUNT; i++)
+    {
+        imx233_lradc_clear_channel(chan);
+        imx233_lradc_kick_channel(chan);
+        imx233_lradc_wait_channel(chan);
+        a += imx233_lradc_read_channel(chan);
+    }
+    /* setup channel for small accumulation */
+    /* set current source to 20µA */
+    imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__20uA);
+    /* read value */
+    int b = 0;
+    for(int i = 0; i < EXT_TEMP_ACC_COUNT; i++)
+    {
+        imx233_lradc_clear_channel(chan);
+        imx233_lradc_kick_channel(chan);
+        imx233_lradc_wait_channel(chan);
+        b += imx233_lradc_read_channel(chan);
+    }
+    /* disable sensor current */
+    imx233_lradc_set_temp_isrc(sensor, HW_LRADC_CTRL2__TEMP_ISRC__0uA);
+    
+    return (b - a) / EXT_TEMP_ACC_COUNT;
+}
+
 void imx233_lradc_setup_battery_conversion(bool automatic, unsigned long scale_factor)
 {
     __REG_CLR(HW_LRADC_CONVERSION) = HW_LRADC_CONVERSION__SCALE_FACTOR_BM;
@@ -159,4 +218,20 @@ void imx233_lradc_init(void)
     // set frequency
     __REG_CLR(HW_LRADC_CTRL3) = HW_LRADC_CTRL3__CYCLE_TIME_BM;
     __REG_SET(HW_LRADC_CTRL3) = HW_LRADC_CTRL3__CYCLE_TIME__6MHz;
+    // setup battery
+    battery_chan = 7;
+    imx233_lradc_reserve_channel(battery_chan);
+    /* setup them for the simplest use: no accumulation, no division*/
+    imx233_lradc_setup_channel(battery_chan, false, false, 0, HW_LRADC_CHANNEL_BATTERY);
+    /* setup delay channel for battery for automatic reading and scaling */
+    battery_delay_chan = 0;
+    imx233_lradc_reserve_delay(battery_delay_chan);
+    /* setup delay to trigger battery channel and retrigger itself.
+     * The counter runs at 2KHz so a delay of 200 will trigger 10
+     * conversions per seconds */
+    imx233_lradc_setup_delay(battery_delay_chan, 1 << battery_chan,
+        1 << battery_delay_chan, 0, 200);
+    imx233_lradc_kick_delay(battery_delay_chan);
+    /* enable automatic conversion, use Li-Ion type battery */
+    imx233_lradc_setup_battery_conversion(true, HW_LRADC_CONVERSION__SCALE_FACTOR__LI_ION);
 }