pbio/main: Introduce deinit.

Now we have exit points to match the entries for drv, pbio, and sys.

We can already use it to call port deinit, but we'll be closing other processes too.

Author: laurensvalk

lib/pbio/include/pbio/main.h

@@ -9,6 +9,7 @@
 #include "pbio/config.h"
 
 void pbio_init(bool start_processes);
+void pbio_deinit(void);
 void pbio_stop_all(bool reset);
 
 #endif // _PBIO_MAIN_H_

lib/pbio/src/main.c

@@ -8,18 +8,9 @@
 
 #include <stdbool.h>
 
-#include <contiki.h>
-
-#include <pbdrv/button.h>
-#include <pbdrv/config.h>
-#include <pbdrv/core.h>
 #include <pbdrv/sound.h>
-#include <pbio/config.h>
-#include <pbio/dcmotor.h>
+
 #include <pbio/imu.h>
-#include <pbio/light_matrix.h>
-#include <pbio/light.h>
-#include <pbio/main.h>
 #include <pbio/motor_process.h>
 #include <pbio/port_interface.h>
 
@@ -35,7 +26,6 @@
  *                               tests that test one driver at a time.
  */
 void pbio_init(bool start_processes) {
-    pbdrv_init();
 
     pbio_imu_init();
 
@@ -51,14 +41,23 @@ void pbio_init(bool start_processes) {
 }
 
 /**
- * Stops all user-level background processes. Drivers and OS-level processes
- * continue running.
+ * Deinitialize pbio modules that are not needed after soft-poweroff.
+ */
+void pbio_deinit(void) {
+    // Power off sensors and motors, including the ones that are always powered.
+    pbio_port_power_off();
+}
+
+/**
+ * Stops all user-level background processes. Called when the user application
+ * completes to get these modules back into their default state. Drivers and
+ * OS-level processes continue running.
  *
  * @param [in]  reset  Whether to reset all user-level processes to a clean
  *                     state (true), or whether to only stop active outputs
- *                     like sound or motors (false). The latter is useful
- *                     to preserve the state for debugging, without sound
- *                     or movement getting in the way or out of control.
+ *                     like sound or motors (false). The latter is useful to
+ *                     preserve the state for debugging, without sound or
+ *                     movement getting in the way, or out of control.
  */
 void pbio_stop_all(bool reset) {
     #if PBIO_CONFIG_LIGHT

lib/pbio/sys/core.c

@@ -65,6 +65,9 @@ void pbsys_init(void) {
 
 void pbsys_deinit(void) {
 
+    pbsys_status_clear(PBIO_PYBRICKS_STATUS_BLE_ADVERTISING);
+    pbsys_status_clear(PBIO_PYBRICKS_STATUS_BLE_HOST_CONNECTED);
+
     pbsys_storage_deinit();
     pbsys_hub_light_matrix_deinit();
 

lib/pbio/sys/main.c

@@ -81,6 +81,7 @@ pbio_error_t pbsys_main_program_request_start(pbio_pybricks_user_program_id_t id
  */
 int main(int argc, char **argv) {
 
+    pbdrv_init();
     pbio_init(true);
     pbsys_init();
 
@@ -131,17 +132,16 @@ int main(int argc, char **argv) {
         }
     }
 
-    // Power off sensors and motors, including the ones that are always powered.
-    // This also makes it easier to see that users can let go of the button.
-    pbio_port_power_off();
-
-    // Stop system processes and save user data before we shutdown.
-    pbsys_status_clear(PBIO_PYBRICKS_STATUS_BLE_ADVERTISING);
-    pbsys_status_clear(PBIO_PYBRICKS_STATUS_BLE_HOST_CONNECTED);
+    // Stop system processes and selected drivers in reverse order. This will
+    // also save user data to flash,
     pbsys_deinit();
 
     // Now lower-level processes may shutdown and/or power off.
+    pbio_deinit();
     pbdrv_deinit();
+
+    // REVISIT: We should use the deinit hooks above to gracefully request exit
+    // instead of having the drivers rely on system statuses.
     pbsys_status_set(PBIO_PYBRICKS_STATUS_SHUTDOWN);
 
     // The power could be held on due to someone pressing the center button