pbio/drv/core: Drop process autostart.

This was a longstanding chore that we have done gradually over time.

The ADC driver was the last to be tranformed to the manual start format.

To ensure that this isn't a potentially breaking change in itself, we move the call to initialize the ADC driver to the end of pbdrv_init, which is where the process was previously auto-started.

Author: laurensvalk

lib/pbio/drv/adc/adc.h

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2024 The Pybricks Authors
+
+// Internal common adc functions.
+
+#ifndef _INTERNAL_PBDRV_ADC_H_
+#define _INTERNAL_PBDRV_ADC_H_
+
+#include <pbdrv/config.h>
+
+#if PBDRV_CONFIG_ADC
+
+void pbdrv_adc_init(void);
+
+#else // PBDRV_CONFIG_ADC
+
+#define pbdrv_adc_init()
+
+#endif // PBDRV_CONFIG_ADC
+
+#endif // _INTERNAL_PBDRV_ADC_H_

lib/pbio/drv/adc/adc_stm32_hal.c

@@ -81,11 +81,7 @@ static void pbdrv_adc_exit(void) {
     HAL_DMA_DeInit(&pbdrv_adc_hdma);
 }
 
-PROCESS_THREAD(pbdrv_adc_process, ev, data) {
-    PROCESS_POLLHANDLER(pbdrv_adc_poll());
-    PROCESS_EXITHANDLER(pbdrv_adc_exit());
-
-    PROCESS_BEGIN();
+void pbdrv_adc_init(void) {
 
     // Timer to trigger ADC
 
@@ -149,6 +145,15 @@ PROCESS_THREAD(pbdrv_adc_process, ev, data) {
     HAL_ADC_Start_DMA(&pbdrv_adc_hadc, pbdrv_adc_dma_buffer, PBIO_ARRAY_SIZE(pbdrv_adc_dma_buffer));
     HAL_TIM_Base_Start(&pbdrv_adc_htim);
 
+    process_start(&pbdrv_adc_process);
+}
+
+PROCESS_THREAD(pbdrv_adc_process, ev, data) {
+    PROCESS_POLLHANDLER(pbdrv_adc_poll());
+    PROCESS_EXITHANDLER(pbdrv_adc_exit());
+
+    PROCESS_BEGIN();
+
     while (true) {
         PROCESS_WAIT_EVENT();
     }

lib/pbio/drv/adc/adc_stm32f0.c

@@ -35,7 +35,7 @@ static void pbdrv_adc_calibrate(void) {
     }
 }
 
-static void pbdrv_adc_init(void) {
+void pbdrv_adc_init(void) {
     // enable power domain
     RCC->APB2ENR |= RCC_APB2ENR_ADCEN;
 
@@ -61,6 +61,8 @@ static void pbdrv_adc_init(void) {
     // TODO: LEGO firmware reads CH 3 during init 10 times and averages it.
     // Not sure what this is measuring or what it would be used for. Perhaps
     // some kind of ID resistor?
+
+    process_start(&pbdrv_adc_process);
 }
 
 // does a single conversion for the specified channel
@@ -91,8 +93,6 @@ PROCESS_THREAD(pbdrv_adc_process, ev, data) {
 
     PROCESS_BEGIN();
 
-    pbdrv_adc_init();
-
     while (true) {
         PROCESS_WAIT_EVENT();
     }

lib/pbio/drv/core.c

@@ -6,6 +6,7 @@
 #include <pbdrv/config.h>
 
 #include "core.h"
+#include "adc/adc.h"
 #include "battery/battery.h"
 #include "block_device/block_device.h"
 #include "bluetooth/bluetooth.h"
@@ -78,4 +79,8 @@ void pbdrv_init(void) {
     // devices behaves the same as if unknown devices are still syncing up after
     // just being plugged in.
     pbdrv_legodev_init();
+
+    // REVISIT: verify that the order does not matter and that we can start this
+    // in the same place as the other drivers above.
+    pbdrv_adc_init();
 }

lib/pbio/drv/uart/uart_stm32f0.c

@@ -21,7 +21,6 @@
 #include <pbio/error.h>
 #include <pbio/util.h>
 
-#include "../../src/processes.h"
 #include "../core.h"
 
 #include "stm32f0xx.h"

lib/pbio/drv/uart/uart_stm32f4_ll_irq.c

@@ -23,7 +23,6 @@
 
 #include "../core.h"
 #include "./uart_stm32f4_ll_irq.h"
-#include "../../src/processes.h"
 
 #define RX_DATA_SIZE 64 // must be power of 2 for ring buffer!
 

lib/pbio/drv/uart/uart_stm32l4_ll_dma.c

@@ -20,7 +20,6 @@
 #include <pbio/util.h>
 
 #include "./uart_stm32l4_ll_dma.h"
-#include "../../src/processes.h"
 #include "../core.h"
 
 #include "stm32l4xx_ll_dma.h"

lib/pbio/src/main.c

@@ -23,15 +23,6 @@
 #include <pbio/motor_process.h>
 
 #include "light/animation.h"
-#include "processes.h"
-
-// DO NOT ADD NEW PROCESSES HERE!
-// We are trying to remove the use of autostart.
-AUTOSTART_PROCESSES(
-#if PBDRV_CONFIG_ADC
-    &pbdrv_adc_process,
-#endif
-    NULL);
 
 /**
  * Initialize the Pybricks I/O Library. This function must be called once,
@@ -41,10 +32,6 @@ AUTOSTART_PROCESSES(
 void pbio_init(void) {
     pbdrv_init();
 
-    // TODO: remove autostart - this currently starts legacy drivers like analog
-    // it has to be after pbdrv_init() but before anything else
-    autostart_start(autostart_processes);
-
     #if PBIO_CONFIG_MOTOR_PROCESS_AUTO_START
     pbio_motor_process_start();
     #endif

lib/pbio/src/processes.h

@@ -26,7 +26,6 @@
 #include <pbio/servo.h>
 #include <test-pbio.h>
 
-#include "../src/processes.h"
 #include "../drv/core.h"
 #include "../drv/clock/clock_test.h"
 #include "../drv/motor_driver/motor_driver_virtual_simulation.h"