Added ADC gem.

Signed-off-by: Yilin Sun <imi415@imi.moe>

mrbgems/machine-adc/mrbgem.rake

@@ -0,0 +1,5 @@
+MRuby::Gem::Specification.new('machine-adc') do |spec|
+  spec.license = 'MIT'
+  spec.author  = 'imi415'
+  spec.summary = 'Analog to digital converter access'
+end

mrbgems/machine-adc/src/adc.c

@@ -0,0 +1,66 @@
+#include <mruby.h>
+#include <mruby/class.h>
+#include <mruby/data.h>
+#include <mruby/hash.h>
+
+/* Private */
+#include "adc.h"
+
+typedef struct {
+    uint32_t pin;
+} mrb_adc_t;
+
+static void mrb_adc_free(mrb_state *mrb, void *ptr);
+
+const struct mrb_data_type mrb_adc_type = {
+    .struct_name = "ADC",
+    .dfree       = mrb_adc_free,
+};
+
+static void mrb_adc_free(mrb_state *mrb, void *ptr) {
+    mrb_free(mrb, ptr);
+}
+
+static mrb_value mrb_adc_initialize(mrb_state *mrb, mrb_value self) {
+    mrb_value init_cfg = mrb_get_arg1(mrb);
+    mrb_ensure_hash_type(mrb, init_cfg);
+
+    mrb_value pin_num = mrb_hash_get(mrb, init_cfg, mrb_symbol_value(mrb_intern_static(mrb, "pin", 3)));
+    mrb_ensure_integer_type(mrb, pin_num);
+
+    mrb_adc_t *analog_pin = mrb_malloc(mrb, sizeof(mrb_adc_t));
+
+    analog_pin->pin = mrb_integer(pin_num);
+
+    mrb_machine_adc_impl_config(analog_pin->pin);
+
+    DATA_PTR(self)  = analog_pin;
+    DATA_TYPE(self) = &mrb_adc_type;
+
+    return self;
+}
+
+static mrb_value mrb_adc_value(mrb_state *mrb, mrb_value self) {
+    mrb_adc_t *analog_pin = mrb_data_get_ptr(mrb, self, &mrb_adc_type);
+    if (analog_pin == NULL) {
+        mrb_raise(mrb, E_RUNTIME_ERROR, "Uninitialized ADC struct");
+    }
+
+    uint32_t adc_uv = mrb_machine_adc_impl_read(analog_pin->pin);
+
+    return mrb_int_value(mrb, adc_uv);
+}
+
+void mrb_machine_adc_gem_init(mrb_state *mrb) {
+    struct RClass *module_machine = mrb_define_module(mrb, "Machine");
+    struct RClass *class_adc      = mrb_define_class_under(mrb, module_machine, "ADC", mrb->object_class);
+
+    MRB_SET_INSTANCE_TT(class_adc, MRB_TT_CDATA);
+
+    mrb_define_method(mrb, class_adc, "initialize", mrb_adc_initialize, MRB_ARGS_ARG(1, 0));
+    mrb_define_method(mrb, class_adc, "value", mrb_adc_value, MRB_ARGS_NONE());
+}
+
+void mrb_machine_adc_gem_final(mrb_state *mrb) {
+    /* Unused */
+}

mrbgems/machine-adc/src/adc.h

@@ -0,0 +1,9 @@
+#ifndef MRBGEMS_MACHINE_ADC_ADC_H
+#define MRBGEMS_MACHINE_ADC_ADC_H
+
+#include <stdint.h>
+
+int mrb_machine_adc_impl_config(uint32_t pin);
+int mrb_machine_adc_impl_read(uint32_t pin);
+
+#endif  // MRBGEMS_MACHINE_ADC_ADC_H

mrbgems/machine-gpio/src/gpio.c

@@ -62,7 +62,6 @@ static mrb_value mrb_gpio_initialize(mrb_state *mrb, mrb_value self) {
         }
     }
 
-    /* TODO: Allocate mrb_gpio_t and store configuration */
     mrb_gpio_t *pin = mrb_malloc(mrb, sizeof(mrb_gpio_t));
 
     pin->pin               = mrb_integer(pin_num);

mrbgems/machine.gembox

@@ -1,4 +1,5 @@
 MRuby::GemBox.new do |conf|
+    conf.gem :core => "../../mrbgems/machine-adc"
     conf.gem :core => "../../mrbgems/machine-devmem"
     conf.gem :core => "../../mrbgems/machine-gpio"
 end