stmhal/adc: Add "mask" selection parameter to pyb.ADCAll constructor.

dpgeorge · dpgeorge · commit 029f215eadcc · 2016-11-29T14:32:05.000+11:00
The "mask" parameter is used to select which pins the ADCAll constructor
will initialise to analog mode.  It defaults to all pins (0xffffffff),
which is backwards compatible with previous behaviour.
diff --git a/stmhal/adc.c b/stmhal/adc.c
@@ -426,7 +426,7 @@ typedef struct _pyb_adc_all_obj_t {
     ADC_HandleTypeDef handle;
 } pyb_adc_all_obj_t;
 
-void adc_init_all(pyb_adc_all_obj_t *adc_all, uint32_t resolution) {
+void adc_init_all(pyb_adc_all_obj_t *adc_all, uint32_t resolution, uint32_t en_mask) {
 
     switch (resolution) {
         case 6:  resolution = ADC_RESOLUTION6b;  break;
@@ -439,15 +439,20 @@ void adc_init_all(pyb_adc_all_obj_t *adc_all, uint32_t resolution) {
     }
 
     for (uint32_t channel = ADC_FIRST_GPIO_CHANNEL; channel <= ADC_LAST_GPIO_CHANNEL; ++channel) {
-        // Channels 0-16 correspond to real pins. Configure the GPIO pin in
-        // ADC mode.
-        const pin_obj_t *pin = pin_adc1[channel];
-        mp_hal_gpio_clock_enable(pin->gpio);
-        GPIO_InitTypeDef GPIO_InitStructure;
-        GPIO_InitStructure.Pin = pin->pin_mask;
-        GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
-        GPIO_InitStructure.Pull = GPIO_NOPULL;
-        HAL_GPIO_Init(pin->gpio, &GPIO_InitStructure);
+        // only initialise those channels that are selected with the en_mask
+        if (en_mask & (1 << channel)) {
+            // Channels 0-16 correspond to real pins. Configure the GPIO pin in
+            // ADC mode.
+            const pin_obj_t *pin = pin_adc1[channel];
+            if (pin) {
+                mp_hal_gpio_clock_enable(pin->gpio);
+                GPIO_InitTypeDef GPIO_InitStructure;
+                GPIO_InitStructure.Pin = pin->pin_mask;
+                GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
+                GPIO_InitStructure.Pull = GPIO_NOPULL;
+                HAL_GPIO_Init(pin->gpio, &GPIO_InitStructure);
+            }
+        }
     }
 
     adcx_clock_enable();
@@ -536,12 +541,17 @@ float adc_read_core_vref(ADC_HandleTypeDef *adcHandle) {
 
 STATIC mp_obj_t adc_all_make_new(const mp_obj_type_t *type, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
     // check number of arguments
-    mp_arg_check_num(n_args, n_kw, 1, 1, false);
+    mp_arg_check_num(n_args, n_kw, 1, 2, false);
 
     // make ADCAll object
     pyb_adc_all_obj_t *o = m_new_obj(pyb_adc_all_obj_t);
     o->base.type = &pyb_adc_all_type;
-    adc_init_all(o, mp_obj_get_int(args[0])); // args[0] is the resolution
+    mp_int_t res = mp_obj_get_int(args[0]);
+    uint32_t en_mask = 0xffffffff;
+    if (n_args > 1) {
+        en_mask =  mp_obj_get_int(args[1]);
+    }
+    adc_init_all(o, res, en_mask);
 
     return o;
 }
