stmhal: Clean up DAC code a little.

stmhal/dac.c

@@ -96,11 +96,18 @@ STATIC void TIM6_Config(uint freq) {
 /******************************************************************************/
 // Micro Python bindings
 
+typedef enum {
+    DAC_STATE_RESET,
+    DAC_STATE_WRITE_SINGLE,
+    DAC_STATE_BUILTIN_WAVEFORM,
+    DAC_STATE_DMA_WAVEFORM,
+} pyb_dac_state_t;
+
 typedef struct _pyb_dac_obj_t {
     mp_obj_base_t base;
     uint32_t dac_channel; // DAC_CHANNEL_1 or DAC_CHANNEL_2
     DMA_Stream_TypeDef *dma_stream; // DMA1_Stream5 or DMA1_Stream6
-    mp_uint_t state;
+    pyb_dac_state_t state;
 } pyb_dac_obj_t;
 
 // create the dac object
@@ -163,7 +170,7 @@ STATIC mp_obj_t pyb_dac_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n
         HAL_DAC_Stop_DMA(&DAC_Handle, dac->dac_channel);
     }
 
-    dac->state = 0;
+    dac->state = DAC_STATE_RESET;
 
     // return object
     return dac;
@@ -179,13 +186,13 @@ STATIC mp_obj_t pyb_dac_noise(mp_obj_t self_in, mp_obj_t freq) {
     // set TIM6 to trigger the DAC at the given frequency
     TIM6_Config(mp_obj_get_int(freq));
 
-    if (self->state != 2) {
+    if (self->state != DAC_STATE_BUILTIN_WAVEFORM) {
         // configure DAC to trigger via TIM6
         DAC_ChannelConfTypeDef config;
         config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
         config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
         HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
-        self->state = 2;
+        self->state = DAC_STATE_BUILTIN_WAVEFORM;
     }
 
     // set noise wave generation
@@ -209,13 +216,13 @@ STATIC mp_obj_t pyb_dac_triangle(mp_obj_t self_in, mp_obj_t freq) {
     // set TIM6 to trigger the DAC at the given frequency
     TIM6_Config(mp_obj_get_int(freq));
 
-    if (self->state != 2) {
+    if (self->state != DAC_STATE_BUILTIN_WAVEFORM) {
         // configure DAC to trigger via TIM6
         DAC_ChannelConfTypeDef config;
         config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
         config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
         HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
-        self->state = 2;
+        self->state = DAC_STATE_BUILTIN_WAVEFORM;
     }
 
     // set triangle wave generation
@@ -233,12 +240,12 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_triangle_obj, pyb_dac_triangle);
 STATIC mp_obj_t pyb_dac_write(mp_obj_t self_in, mp_obj_t val) {
     pyb_dac_obj_t *self = self_in;
 
-    if (self->state != 1) {
+    if (self->state != DAC_STATE_WRITE_SINGLE) {
         DAC_ChannelConfTypeDef config;
         config.DAC_Trigger = DAC_TRIGGER_NONE;
         config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
         HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
-        self->state = 1;
+        self->state = DAC_STATE_WRITE_SINGLE;
     }
 
     HAL_DAC_SetValue(&DAC_Handle, self->dac_channel, DAC_ALIGN_8B_R, mp_obj_get_int(val));
@@ -258,26 +265,24 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_dac_write_obj, pyb_dac_write);
 /// TIM6 is used to control the frequency of the transfer.
 // TODO add callback argument, to call when transfer is finished
 // TODO add double buffer argument
-STATIC const mp_arg_t pyb_dac_write_timed_args[] = {
-    { MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
-    { MP_QSTR_freq, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
-    { MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DMA_NORMAL} },
-};
-#define PYB_DAC_WRITE_TIMED_NUM_ARGS MP_ARRAY_SIZE(pyb_dac_write_timed_args)
-
-mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
-    pyb_dac_obj_t *self = args[0];
+mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_data, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_freq, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DMA_NORMAL} },
+    };
 
     // parse args
-    mp_arg_val_t vals[PYB_DAC_WRITE_TIMED_NUM_ARGS];
-    mp_arg_parse_all(n_args - 1, args + 1, kw_args, PYB_DAC_WRITE_TIMED_NUM_ARGS, pyb_dac_write_timed_args, vals);
+    pyb_dac_obj_t *self = pos_args[0];
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
     // get the data to write
     mp_buffer_info_t bufinfo;
-    mp_get_buffer_raise(vals[0].u_obj, &bufinfo, MP_BUFFER_READ);
+    mp_get_buffer_raise(args[0].u_obj, &bufinfo, MP_BUFFER_READ);
 
     // set TIM6 to trigger the DAC at the given frequency
-    TIM6_Config(vals[1].u_int);
+    TIM6_Config(args[1].u_int);
 
     __DMA1_CLK_ENABLE();
 
@@ -313,7 +318,7 @@ mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *k
     DMA_Handle.Init.MemInc = DMA_MINC_ENABLE;
     DMA_Handle.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
     DMA_Handle.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
-    DMA_Handle.Init.Mode = vals[2].u_int;
+    DMA_Handle.Init.Mode = args[2].u_int;
     DMA_Handle.Init.Priority = DMA_PRIORITY_HIGH;
     DMA_Handle.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
     DMA_Handle.Init.FIFOThreshold = DMA_FIFO_THRESHOLD_HALFFULL;
@@ -331,12 +336,12 @@ mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *k
     DAC_Handle.State = HAL_DAC_STATE_RESET;
     HAL_DAC_Init(&DAC_Handle);
 
-    if (self->state != 3) {
+    if (self->state != DAC_STATE_DMA_WAVEFORM) {
         DAC_ChannelConfTypeDef config;
         config.DAC_Trigger = DAC_TRIGGER_T6_TRGO;
         config.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
         HAL_DAC_ConfigChannel(&DAC_Handle, &config, self->dac_channel);
-        self->state = 3;
+        self->state = DAC_STATE_DMA_WAVEFORM;
     }
 
     HAL_DAC_Start_DMA(&DAC_Handle, self->dac_channel, (uint32_t*)bufinfo.buf, bufinfo.len, DAC_ALIGN_8B_R);