Refactor SI command handling to reduce memory usage, make command logic platform independent

firmware/libsi/CMakeLists.txt

@@ -5,7 +5,7 @@ cmake_minimum_required(VERSION "3.21")
 project(si LANGUAGES C)
 
 # Define the library
-add_library(si STATIC "src/crc8.c" "src/commands.c" "src/device/gc_controller.c")
+add_library(si STATIC "src/crc8.c" "src/device/commands.c" "src/device/gc_controller.c")
 
 # Configure SI peripheral selection
 if(DEFINED SI_RX_TIMER_IDX)

firmware/libsi/include/si/commands.h → firmware/libsi/include/si/device/commands.h

@@ -3,7 +3,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include "si.h"
+#include "si/si.h"
 
 /**
  * Function type for command handlers.
@@ -14,42 +14,45 @@
  *
  * @return 0 on success, negative error code on failure
  */
-typedef int (*si_command_handler_fn)(const uint8_t *command, si_callback_fn callback, void *context);
+typedef int (*si_command_handler_fn)(const uint8_t *command, si_complete_cb_t callback, void *context);
+
+/**
+ * Command structure representing a registered command.
+ */
+struct si_command {
+  uint8_t command;
+  uint8_t length;
+  si_command_handler_fn handler;
+  void *user_data;
+};
 
 /**
  * Register a command handler for commands from an SI host.
  *
  * @param command the command to handle
- * @param command_length the length of the command
+ * @param command_length the length of the command in bytes
  * @param handler the command handler function
  *
  */
 void si_command_register(uint8_t command, uint8_t length, si_command_handler_fn handler, void *context);
 
 /**
- * Get the expected length of an SI command.
- *
- * @param command the command to check
- *
- * @return the expected length of the command, in bytes, or 0 if the command is unknown
- */
-uint8_t si_command_get_length(uint8_t command);
-
-/**
- * Get the command handler for an SI command.
+ * Look up a command structure by command ID.
  *
- * @param command the command to check
+ * @param command the command ID to look up
  *
- * @return the command handler function, or NULL if the command is unknown
+ * @return pointer to the command structure, or NULL if not found
  */
-si_command_handler_fn si_command_get_handler(uint8_t command);
+struct si_command *si_command_find_by_id(uint8_t command);
 
 /**
- * Process an SI command.
+ * Process a single SI command on the bus.
  *
+ * This will read a command from the SI bus and call the registered handler.
  *
+ * @param await_bus_idle if true, will wait for the SI bus to be idle before reading commands
  */
-void si_command_process();
+void si_command_process(bool await_bus_idle);
 
 /**
  * Enable automatic command processing.

firmware/libsi/include/si/device/gc_controller.h

@@ -7,6 +7,31 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+// GameCube controller commands
+#define SI_CMD_GC_SHORT_POLL        0x40
+#define SI_CMD_GC_SHORT_POLL_LEN    3
+#define SI_CMD_GC_SHORT_POLL_RESP   8
+
+#define SI_CMD_GC_READ_ORIGIN       0x41
+#define SI_CMD_GC_READ_ORIGIN_LEN   1
+#define SI_CMD_GC_READ_ORIGIN_RESP  10
+
+#define SI_CMD_GC_CALIBRATE         0x42
+#define SI_CMD_GC_CALIBRATE_LEN     3
+#define SI_CMD_GC_CALIBRATE_RESP    10
+
+#define SI_CMD_GC_LONG_POLL         0x43
+#define SI_CMD_GC_LONG_POLL_LEN     3
+#define SI_CMD_GC_LONG_POLL_RESP    10
+
+#define SI_CMD_GC_PROBE_DEVICE      0x4D
+#define SI_CMD_GC_PROBE_DEVICE_LEN  3
+#define SI_CMD_GC_PROBE_DEVICE_RESP 8
+
+#define SI_CMD_GC_FIX_DEVICE        0x4E
+#define SI_CMD_GC_FIX_DEVICE_LEN    3
+#define SI_CMD_GC_FIX_DEVICE_RESP   3
+
 /**
  * Rumble motor states.
  */
@@ -88,7 +113,6 @@ struct si_device_gc_controller {
  *
  * @param device the device to initialize
  * @param type the device type flags
- * @param input_state pointer to an input state buffer
  */
 void si_device_gc_init(struct si_device_gc_controller *device, uint8_t type);
 

firmware/libsi/include/si/si.h

@@ -41,6 +41,7 @@
 
 #pragma once
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -56,31 +57,6 @@
 #define SI_CMD_INFO_LEN             1
 #define SI_CMD_INFO_RESP            3
 
-// GameCube controller commands
-#define SI_CMD_GC_SHORT_POLL        0x40
-#define SI_CMD_GC_SHORT_POLL_LEN    3
-#define SI_CMD_GC_SHORT_POLL_RESP   8
-
-#define SI_CMD_GC_READ_ORIGIN       0x41
-#define SI_CMD_GC_READ_ORIGIN_LEN   1
-#define SI_CMD_GC_READ_ORIGIN_RESP  10
-
-#define SI_CMD_GC_CALIBRATE         0x42
-#define SI_CMD_GC_CALIBRATE_LEN     3
-#define SI_CMD_GC_CALIBRATE_RESP    10
-
-#define SI_CMD_GC_LONG_POLL         0x43
-#define SI_CMD_GC_LONG_POLL_LEN     3
-#define SI_CMD_GC_LONG_POLL_RESP    10
-
-#define SI_CMD_GC_PROBE_DEVICE      0x4D
-#define SI_CMD_GC_PROBE_DEVICE_LEN  3
-#define SI_CMD_GC_PROBE_DEVICE_RESP 8
-
-#define SI_CMD_GC_FIX_DEVICE        0x4E
-#define SI_CMD_GC_FIX_DEVICE_LEN    3
-#define SI_CMD_GC_FIX_DEVICE_RESP   3
-
 // SI device info flags
 // On wireless controllers 0x00C0FF is reserved for the controller ID
 
@@ -118,12 +94,21 @@ enum {
   SI_ERR_TRANSFER_TIMEOUT,
 };
 
+/**
+ * Function type for per-byte callbacks during receive operations.
+ *
+ * @param byte the received byte
+ * @param byte_index the zero-based index of the byte (0 for first byte)
+ * @return true to continue the transfer, false to stop it
+ */
+typedef bool (*si_byte_cb_t)(uint8_t byte, uint8_t byte_index);
+
 /**
  * Function type for transfer completion callbacks.
  *
- * @param result 0 on success, negative error code on failure
+ * @param result positive number of bytes read on success, negative error code on failure
  */
-typedef void (*si_callback_fn)(int result);
+typedef void (*si_complete_cb_t)(int result);
 
 /**
  * Initialize the SI bus.
@@ -143,24 +128,17 @@ void si_init(uint8_t port, uint8_t pin, uint8_t mode, uint32_t rx_freq, uint32_t
  * @param length the length of the data
  * @param callback function to call when the transfer is complete
  */
-void si_write_bytes(const uint8_t *data, uint8_t length, si_callback_fn callback);
+void si_write_bytes(const uint8_t *data, uint8_t length, si_complete_cb_t callback);
 
 /**
  * Read data from the SI bus.
  *
  * @param buffer the buffer to read into
- * @param length the number of bytes expected
- * @param callback function to call when the transfer is complete
- */
-void si_read_bytes(uint8_t *buffer, uint8_t length, si_callback_fn callback);
-
-/**
- * Read a single command from the SI bus.
- *
- * @param buffer the buffer to read into
- * @param callback function to call when the command has been read
+ * @param max_length the maximum number of bytes to read (buffer size)
+ * @param byte_callback optional function to call for each received byte (can be NULL)
+ * @param complete_callback function to call when the transfer is complete
  */
-void si_read_command(uint8_t *buffer, si_callback_fn callback);
+void si_read_bytes(uint8_t *buffer, uint8_t max_length, si_byte_cb_t byte_callback, si_complete_cb_t complete_callback);
 
 /**
  * Wait for the SI bus to be idle.