pico: SPI-mode SD card support

32blit-pico/CMakeLists.txt

@@ -38,7 +38,6 @@ target_sources(BlitHalPico INTERFACE
     ${CMAKE_CURRENT_LIST_DIR}/file.cpp
     ${CMAKE_CURRENT_LIST_DIR}/led.cpp
     ${CMAKE_CURRENT_LIST_DIR}/main.cpp
-    ${CMAKE_CURRENT_LIST_DIR}/storage.cpp
     ${CMAKE_CURRENT_LIST_DIR}/multiplayer.cpp
     ${CMAKE_CURRENT_LIST_DIR}/st7789.cpp
     ${CMAKE_CURRENT_LIST_DIR}/usb_descriptors.c
@@ -99,6 +98,9 @@ endif()
 if(NOT BLIT_INPUT_DRIVER)
     set(BLIT_INPUT_DRIVER "none")
 endif()
+if(NOT BLIT_STORAGE_DRIVER)
+    set(BLIT_STORAGE_DRIVER "flash")
+endif()
 if(NOT BLIT_USB_DRIVER)
     set(BLIT_USB_DRIVER "device")
 endif()
@@ -124,6 +126,10 @@ if(BLIT_INPUT_DRIVER STREQUAL "usb_hid")
     list(APPEND BLIT_BOARD_DEFINITIONS INPUT_USB_HID)
 endif()
 
+if(BLIT_STORAGE_DRIVER STREQUAL "sd_spi")
+    list(APPEND BLIT_BOARD_DEFINITIONS STORAGE_SD)
+endif()
+
 if(BLIT_USB_DRIVER STREQUAL "host")
     list(APPEND BLIT_BOARD_DEFINITIONS USB_HOST)
     list(APPEND BLIT_BOARD_LIBRARIES tinyusb_host)
@@ -139,12 +145,14 @@ pico_sdk_init()
 
 # generate PIO headers (has to be after SDK init)
 pico_generate_pio_header(BlitHalPico ${CMAKE_CURRENT_LIST_DIR}/st7789.pio)
+pico_generate_pio_header(BlitHalPico ${CMAKE_CURRENT_LIST_DIR}/spi.pio)
 
 # driver sources
 target_sources(BlitHalPico INTERFACE
     ${CMAKE_CURRENT_LIST_DIR}/audio_${BLIT_AUDIO_DRIVER}.cpp
     ${CMAKE_CURRENT_LIST_DIR}/display_${BLIT_DISPLAY_DRIVER}.cpp
     ${CMAKE_CURRENT_LIST_DIR}/input_${BLIT_INPUT_DRIVER}.cpp
+    ${CMAKE_CURRENT_LIST_DIR}/storage_${BLIT_STORAGE_DRIVER}.cpp
     ${CMAKE_CURRENT_LIST_DIR}/usb_${BLIT_USB_DRIVER}.cpp
 )
 

32blit-pico/board/vgaboard/config.cmake

@@ -9,4 +9,5 @@ set(BLIT_BOARD_DEFINITIONS
 blit_driver(audio i2s)
 blit_driver(display scanvideo)
 blit_driver(input usb_hid)
+blit_driver(storage sd_spi)
 blit_driver(usb host)

32blit-pico/board/vgaboard/config.h

@@ -3,3 +3,9 @@
 #ifndef ALLOW_HIRES
 #define ALLOW_HIRES 0 // disable by default, mode switching isn't supported
 #endif
+
+// spi
+#define SD_SCK   5
+#define SD_MOSI 18
+#define SD_MISO 19
+#define SD_CS   22

32blit-pico/ffconf.h

@@ -192,9 +192,14 @@
 /  arbitrary physical drive and partition listed in the VolToPart[]. Also f_fdisk()
 /  funciton will be available. */
 
-
+#ifdef STORAGE_SD
+#define FF_MIN_SS		512
+#define FF_MAX_SS		512
+#else
 #define FF_MIN_SS		4096
 #define FF_MAX_SS		4096
+#endif
+
 /* This set of options configures the range of sector size to be supported. (512,
 /  1024, 2048 or 4096) Always set both 512 for most systems, generic memory card and
 /  harddisk, but a larger value may be required for on-board flash memory and some

32blit-pico/file.cpp

@@ -12,16 +12,18 @@
 #include "storage.hpp"
 
 static FATFS fs;
+static bool initialised = false;
 
 std::vector<void *> open_files;
 
 // fatfs io funcs
 DSTATUS disk_initialize(BYTE pdrv) {
-  return RES_OK;
+  initialised = storage_init();
+  return initialised ? RES_OK : STA_NOINIT;
 }
 
 DSTATUS disk_status(BYTE pdrv) {
-  return RES_OK; // FIXME: NOINIT?
+  return initialised ? RES_OK : STA_NOINIT;
 }
 
 DRESULT disk_read(BYTE pdrv, BYTE *buff, LBA_t sector, UINT count) {
@@ -57,6 +59,8 @@ DRESULT disk_ioctl(BYTE pdrv, BYTE cmd, void* buff) {
 void init_fs() {
   auto res = f_mount(&fs, "", 1);
 
+  // auto-format flash, but not SD cards
+#ifndef STORAGE_SD
   if(res == FR_NO_FILESYSTEM) {
     printf("No filesystem found, formatting...\n");
 
@@ -71,6 +75,7 @@ void init_fs() {
 
     res = f_mount(&fs, "", 1);
   }
+#endif
 
   if(res != FR_OK)
     printf("Failed to mount filesystem! (%i)\n", res);

32blit-pico/spi.pio

@@ -0,0 +1,4 @@
+.program spi_cpha0
+.side_set 1
+    out pins, 1 side 0
+    in pins, 1  side 1

32blit-pico/storage.hpp

@@ -1,6 +1,8 @@
 #pragma once
 #include <cstdint>
 
+bool storage_init();
+
 void get_storage_size(uint16_t &block_size, uint32_t &num_blocks);
 
 int32_t storage_read(uint32_t sector, uint32_t offset, void *buffer, uint32_t size_bytes);

32blit-pico/storage.cpp → 32blit-pico/storage_flash.cpp

@@ -1,4 +1,4 @@
-// raw storage interface, currently flash
+// raw flash storage interface
 #include "storage.hpp"
 
 #include <cstring>
@@ -15,6 +15,10 @@ static const uint32_t storage_offset = PICO_FLASH_SIZE_BYTES - storage_size;
 
 extern bool core1_started;
 
+bool storage_init() {
+  return true;
+}
+
 void get_storage_size(uint16_t &block_size, uint32_t &num_blocks) {
   block_size = FLASH_SECTOR_SIZE;
   num_blocks = storage_size / FLASH_SECTOR_SIZE;