6 files changed, 130 insertions, 39 deletions
diff --git a/shared/include.cmake b/shared/include.cmake
new file mode 100644
index 0000000..f07a78b
--- /dev/null
+++ b/shared/include.cmake
@@ -0,0 +1,5 @@
+include_directories(${CMAKE_CURRENT_LIST_DIR})
+add_library(puzbus STATIC
+	${CMAKE_CURRENT_LIST_DIR}/pb/driver.c
+	)
+
diff --git a/shared/pb/bus.h b/shared/pb/bus.h
new file mode 100644
index 0000000..6f464c3
--- /dev/null
+++ b/shared/pb/bus.h
@@ -0,0 +1,18 @@
+#pragma once
+
+// Adafruit NeoTrellis modules
+#define BUSADDR_ADA_NEO_1 0x2E
+#define BUSADDR_ADA_NEO_2 0x2F
+#define BUSADDR_ADA_NEO_3 0x30
+#define BUSADDR_ADA_NEO_4 0x32
+
+// TODO: ???
+#define BUSADDR_MOD_NEOTRELLIS 0
+#define BUSADDR_MOD_SOFTWARE 0
+#define BUSADDR_MOD_HARDWARE 0
+#define BUSADDR_MOD_VAULT 0
+// #define BUSADDR_MOD_AUTOMATION 0
+
+// main controller
+#define BUSADDR_MAIN 0x00
+
diff --git a/shared/pb/driver.c b/shared/pb/driver.c
new file mode 100644
index 0000000..2552b61
--- /dev/null
+++ b/shared/pb/driver.c
@@ -0,0 +1,31 @@
+#include "types.h"
+#include "driver.h"
+
+__weak bool pbdrv_hook_cmd() {
+	return false;
+}
+
+__weak void pbdrv_i2c_recv(uint16_t addr, const char * buf, size_t sz) {
+	if (sz == 0) return;
+	enum pb_cmd cmd = (enum pb_cmd) buf[0];
+
+	// shift buffer pointer to only contain the puzzle bus message buf
+	buf++;
+	sz--;
+
+	// allow user to override command handler while still using this weak
+	// function
+	if (pbdrv_hook_cmd(cmd, buf, sz)) return;
+
+	switch (cmd) {
+		case PB_CMD_READ: return pbdrv_handle_read(buf, sz);
+		// case PB_CMD_WRITE: return pbdrv_handle_write(buf, sz);
+		// case PB_CMD_MAGIC: return pbdrv_handle_magic(buf, sz);
+		default: return;
+	}
+}
+
+__weak void pbdrv_i2c_send(uint16_t addr, const char * buf, size_t sz) {
+	return;
+}
+
diff --git a/shared/pb/driver.h b/shared/pb/driver.h
new file mode 100644
index 0000000..1c9c3a3
--- /dev/null
+++ b/shared/pb/driver.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+#include "types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void pbdrv_i2c_recv(uint16_t addr, const char * buf, size_t sz);
+void pbdrv_i2c_send(uint16_t addr, const char * buf, size_t sz);
+
+void pbdrv_hook_state(enum pb_global_state * state, bool rw);
+bool pbdrv_hook_cmd(enum pb_cmd cmd, const char * buf, size_t sz);
+
+void pbdrv_handle_read(const char * buf, size_t sz);
+
+#ifdef __cplusplus
+}
+#endif
+
diff --git a/shared/pb/types.h b/shared/pb/types.h
new file mode 100644
index 0000000..8150194
--- /dev/null
+++ b/shared/pb/types.h
@@ -0,0 +1,52 @@
+#pragma once
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __GNUC__
+#define __packed __attribute__((packed))
+#define __weak __attribute__((weak))
+#endif
+#ifndef __packed
+#error Could not determine packed attribute for current compiler
+#define __packed
+#endif
+#ifndef __weak
+#error Could not determine weak attribute for current compiler
+#define __weak
+#endif
+
+/**
+ * \brief puzzle bus command types
+ *
+ * The first byte of a puzzle bus message's data indicates the command type.
+ */
+enum __packed pb_cmd {
+	PB_CMD_READ,   //!< read a puzzle module property
+	PB_CMD_WRITE,  //!< write to a puzzle module property
+	// PB_CMD_UPDATE, //!< request an update
+};
+
+/** \brief Puzzle bus global states */
+enum __packed pb_global_state {
+	PB_GS_NOINIT,  //!< uninitialized (only used by puzzle modules)
+	PB_GS_IDLE,    //!< puzzle not started yet
+	PB_GS_PLAYING, //!< puzzle actively being solved
+	PB_GS_SOLVED,  //!< puzzle completed
+};
+
+typedef struct __packed {
+	uint8_t address;
+} pb_cmd_read_t;
+
+typedef struct __packed {
+	uint8_t address;
+	uint8_t data[];
+} pb_cmd_write_t;
+
+#ifdef __cplusplus
+}
+#endif
+
diff --git a/shared/puzbus.h b/shared/puzbus.h
deleted file mode 100644
index 59a8867..0000000
--- a/shared/puzbus.h
+++ /dev/null
@@ -1,39 +0,0 @@
-#pragma once
-
-/** \file bus address reference */
-
-// Adafruit NeoTrellis modules
-#define BUSADDR_ADA_NEO_1 0x2E
-#define BUSADDR_ADA_NEO_2 0x2F
-#define BUSADDR_ADA_NEO_3 0x30
-#define BUSADDR_ADA_NEO_4 0x32
-
-// TODO: ???
-#define BUSADDR_MOD_NEOTRELLIS 0
-#define BUSADDR_MOD_SOFTWARE 0
-#define BUSADDR_MOD_HARDWARE 0
-#define BUSADDR_MOD_VAULT 0
-#define BUSADDR_MOD_AUTOMATION 0
-
-// main controller
-#define BUSADDR_MAIN 0x00
-
-/**
- * \brief puzzle bus command types
- *
- * The first byte of a puzzle bus message's data indicates the command type.
- */
-enum pb_cmd {
-	PB_CMD_READ,   //!< read a puzzle module property
-	PB_CMD_WRITE,  //!< write to a puzzle module property
-	// PB_CMD_UPDATE, //!< request an update
-};
-
-/** \brief Puzzle bus global states */
-enum pb_global_state {
-	PB_GS_NOINIT,  //!< uninitialized (only used by puzzle modules)
-	PB_GS_IDLE,    //!< puzzle not started yet
-	PB_GS_PLAYING, //!< puzzle actively being solved
-	PB_GS_SOLVED,  //!< puzzle completed
-};
-