Support for palmtop mic keys in MD9600 keyboard driver

platform/drivers/keyboard/keyboard_MD9600.c

@@ -20,12 +20,60 @@
 
 #include <stdio.h>
 #include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
 #include <interfaces/gpio.h>
 #include <interfaces/delays.h>
 #include <interfaces/keyboard.h>
 #include <interfaces/platform.h>
+#include <ADC1_MDx.h>
 #include "hwconfig.h"
 
+/**
+ * \internal
+ * Helper function which compares two voltages and tells if they're equal within
+ * a 200mV range.
+ *
+ * @param voltage: voltage to be compared against reference, in mV.
+ * @param reference: reference voltage for comparison, in mV.
+ * @return true if voltage is equal to reference ± 200mV, false otherwise.
+ */
+bool _compareVoltages(const int voltage, const int reference)
+{
+    int difference = voltage - reference;
+    if(abs(difference) <= 200) return true;
+    return false;
+}
+
+/*
+ * Mapping of palmtop mic buttons:
+ *
+ *         +-------+-------+-------+-------+
+ *         | Col 0 | Col 1 | Col 2 | Col 3 |
+ * +-------+-------+-------+-------+-------+
+ * | Row 0 |   1   |   2   |   3   |   A   |
+ * +-------+-------+-------+-------+-------+
+ * | Row 1 |   4   |   5   |   6   |   B   |
+ * +-------+-------+-------+-------+-------+
+ * | Row 2 |   7   |   8   |   9   |   C   |
+ * +-------+-------+-------+-------+-------+
+ * | Row 3 |   *   |   0   |   #   |   D   |
+ * +-------+-------+-------+-------+-------+
+ * | Row 4 |       |  A/B  |   UP  | DOWN  |
+ * +-------+-------+-------+-------+-------+
+ *
+ */
+
+static const uint32_t micKeymap[5][4] =
+{
+    {  KEY_1,  KEY_2,   KEY_3,   KEY_F1 },
+    {  KEY_4,  KEY_5,   KEY_6,   KEY_F2 },
+    {  KEY_7,  KEY_8,   KEY_9,   KEY_F3 },
+    {KEY_STAR, KEY_0,  KEY_HASH, KEY_F4 },
+    {   0    , KEY_F5,  KEY_UP, KEY_DOWN}
+};
+
+
 void kbd_init()
 {
     gpio_setMode(KB_COL1, INPUT_PULL_UP);
@@ -109,5 +157,54 @@ keyboard_t kbd_getKeys()
     if(gpio_readPin(KB_COL4) == 0) keys |= KEY_F2;
     gpio_setPin(KB_ROW3);
 
+   /*
+    * Mapping of palmtop mic row/coloumn voltages:
+    *                  +-------+-------+-------+-------+
+    *                  | Col 0 | Col 1 | Col 2 | Col 3 |
+    *                  +-------+-------+-------+-------+
+    *                  | 700mV | 1300mV| 1900mV| 2600mV|
+    * +-------+--------+-------+-------+-------+-------+
+    * | Row 0 | 2600mV |
+    * +-------+--------+
+    * | Row 1 | 2100mV |
+    * +-------+--------+
+    * | Row 2 | 1500mV |
+    * +-------+--------+
+    * | Row 3 | 1000mV |
+    * +-------+--------+
+    * | Row 4 | 500mV  |
+    * +-------+--------+
+    *
+    */
+
+    /* Retrieve row/coloumn voltage measurements. */
+    uint16_t row = ((uint16_t) adc1_getMeasurement(ADC_SW2_CH) + 0.5f);
+    uint16_t col = ((uint16_t) adc1_getMeasurement(ADC_SW1_CH) + 0.5f);
+
+    /* Map row voltage to row index. */
+    uint8_t rowIdx = 0xFF;
+    if(_compareVoltages(row, 2600)) rowIdx = 0;
+    if(_compareVoltages(row, 2100)) rowIdx = 1;
+    if(_compareVoltages(row, 1500)) rowIdx = 2;
+    if(_compareVoltages(row, 1000)) rowIdx = 3;
+    if(_compareVoltages(row,  500)) rowIdx = 4;
+
+    /* Map col voltage to col index. */
+    uint8_t colIdx = 0xFF;
+    if(_compareVoltages(col,  700)) colIdx = 0;
+    if(_compareVoltages(col, 1300)) colIdx = 1;
+    if(_compareVoltages(col, 1900)) colIdx = 2;
+    if(_compareVoltages(col, 2600)) colIdx = 3;
+
+    /*
+     * Get corresponding key.
+     * Having rowIdx or colIdx equal to 0xFF means that no button on the palmtop
+     * key is pressed.
+     */
+    if((rowIdx != 0xFF) && (colIdx != 0xFF))
+    {
+        keys |= micKeymap[rowIdx][colIdx];
+    }
+
     return keys;
 }

platform/targets/MD-9600/platform.c

@@ -41,6 +41,7 @@ void platform_init()
     gpio_setMode(PTT_SW, INPUT);
 
     gpio_setMode(PWR_SW, OUTPUT);
+    gpio_setPin(PWR_SW);
 
     /*
      * Initialise ADC1, for vbat, RSSI, ...
@@ -140,7 +141,7 @@ float platform_getVolumeLevel()
     return 0.0f;
 }
 
-uint8_t platform_getChSelector()
+int8_t platform_getChSelector()
 {
     static const uint8_t rsPositions[] = { 1, 4, 2, 3};
     int pos = gpio_readPin(CH_SELECTOR_0)