simplify and clarify PWMOut shared resource conflict errors

Author: dhalbert

ports/mimxrt10xx/common-hal/pwmio/PWMOut.c

@@ -144,7 +144,7 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
 
         // We want variable frequency but another class has already claim a fixed frequency.
         if (variable_frequency) {
-            return PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE;
+            return PWMOUT_INTERNAL_RESOURCES_IN_USE;
         }
 
         // Another pin is already using this output.
@@ -153,7 +153,7 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
         }
 
         if (frequency != _pwm_sm_frequencies[flexpwm_index][submodule]) {
-            return PWMOUT_INVALID_FREQUENCY_ON_PIN;
+            return PWMOUT_INTERNAL_RESOURCES_IN_USE;
         }
 
         // Submodule is already running at our target frequency and the output

ports/raspberrypi/common-hal/pwmio/PWMOut.c

@@ -78,15 +78,15 @@ pwmout_result_t pwmout_allocate(uint8_t slice, uint8_t ab_channel, bool variable
     if (target_slice_frequencies[slice] > 0) {
         // If we want to change frequency then we can't share.
         if (variable_frequency) {
-            return PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE;
+            return PWMOUT_INTERNAL_RESOURCES_IN_USE;
         }
         // If the other user wants a variable frequency then we can't share either.
         if ((slice_variable_frequency & (1 << slice)) != 0) {
             return PWMOUT_INTERNAL_RESOURCES_IN_USE;
         }
         // If we're both fixed frequency but we don't match target frequencies then we can't share.
         if (target_slice_frequencies[slice] != frequency) {
-            return PWMOUT_INVALID_FREQUENCY_ON_PIN;
+            return PWMOUT_INTERNAL_RESOURCES_IN_USE;
         }
     }
 

ports/stm/common-hal/pwmio/PWMOut.c

@@ -74,12 +74,12 @@ pwmout_result_t common_hal_pwmio_pwmout_construct(pwmio_pwmout_obj_t *self,
                 }
                 // If the frequencies are the same it's ok
                 if (tim_frequencies[tim_index] != frequency) {
-                    last_failure = PWMOUT_INVALID_FREQUENCY_ON_PIN;
+                    last_failure = PWMOUT_INTERNAL_RESOURCES_IN_USE;
                     continue; // keep looking
                 }
                 // you can't put a variable frequency on a partially reserved timer
                 if (variable_frequency) {
-                    last_failure = PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE;
+                    last_failure = PWMOUT_INTERNAL_RESOURCES_IN_USE;
                     continue; // keep looking
                 }
                 first_time_setup = false; // skip setting up the timer

shared-bindings/pwmio/PWMOut.c

@@ -25,14 +25,8 @@ void common_hal_pwmio_pwmout_raise_error(pwmout_result_t result) {
         case PWMOUT_INVALID_FREQUENCY:
             mp_arg_error_invalid(MP_QSTR_frequency);
             break;
-        case PWMOUT_INVALID_FREQUENCY_ON_PIN:
-            mp_arg_error_invalid(MP_QSTR_frequency);
-            break;
-        case PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE:
-            mp_arg_error_invalid(MP_QSTR_variable_frequency);
-            break;
         case PWMOUT_INTERNAL_RESOURCES_IN_USE:
-            mp_raise_RuntimeError(MP_ERROR_TEXT("Internal resource(s) in use"));
+            mp_raise_RuntimeError(MP_ERROR_TEXT("Conflicting settings for shared resource"));
             break;
         default:
         case PWMOUT_INITIALIZATION_ERROR:

shared-bindings/pwmio/PWMOut.h

@@ -15,8 +15,6 @@ typedef enum pwmout_result_t {
     PWMOUT_OK,
     PWMOUT_INVALID_PIN,
     PWMOUT_INVALID_FREQUENCY,
-    PWMOUT_INVALID_FREQUENCY_ON_PIN,
-    PWMOUT_VARIABLE_FREQUENCY_NOT_AVAILABLE,
     PWMOUT_INTERNAL_RESOURCES_IN_USE,
     PWMOUT_INITIALIZATION_ERROR,
 } pwmout_result_t;