atmel-samd: Add mass storage support.

Fixes micropython#260

Author: tannewt

atmel-samd/Makefile

@@ -44,6 +44,7 @@ INC += -I. \
        -Iasf4/$(CHIP_FAMILY)/usb \
        -Iasf4/$(CHIP_FAMILY)/usb/class/cdc \
        -Iasf4/$(CHIP_FAMILY)/usb/class/hid \
+       -Iasf4/$(CHIP_FAMILY)/usb/class/msc \
        -Iasf4/$(CHIP_FAMILY)/usb/device \
        -Iasf4_conf/$(CHIP_FAMILY) \
        -Iboards/$(BOARD) \
@@ -181,6 +182,7 @@ SRC_ASF := \
 	hpl/tc/hpl_tc.c \
 	hpl/usb/hpl_usb.c \
 	usb/class/cdc/device/cdcdf_acm.c \
+	usb/class/msc/device/mscdf.c \
 	usb/device/usbdc.c \
 	usb/usb_protocol.c \
 	hal/utils/src/utils_list.c \
@@ -204,8 +206,7 @@ endif
 SRC_ASF := $(addprefix asf4/$(CHIP_FAMILY)/, $(SRC_ASF))
 
 # Skip this source for now.
-#	access_vfs.c \
-	shared_dma.c \
+#	shared_dma.c \
 
 SRC_C = \
 	background.c \
@@ -216,6 +217,7 @@ SRC_C = \
 	$(CHIP_FAMILY)_pins.c \
 	tick.c \
 	usb.c \
+	usb_mass_storage.c \
 	$(FLASH_IMPL) \
 	bindings/samd/__init__.c \
 	boards/$(BOARD)/board.c \

atmel-samd/access_vfs.c

@@ -39,7 +39,7 @@
 // <CONF_USB_D_N_EP_MAX"> Max possible (by "Max Endpoint Number" config)
 // <id> usbd_num_ep_sp
 #ifndef CONF_USB_D_NUM_EP_SP
-#define CONF_USB_D_NUM_EP_SP CONF_USB_N_4
+#define CONF_USB_D_NUM_EP_SP CONF_USB_D_EP_N_MAX
 #endif
 
 // </h>
@@ -60,7 +60,7 @@
 // <i> The number of physical endpoints - 1
 // <id> usbd_arch_max_ep_n
 #ifndef CONF_USB_D_MAX_EP_N
-#define CONF_USB_D_MAX_EP_N CONF_USB_N_2
+#define CONF_USB_D_MAX_EP_N CONF_USB_D_EP_N_MAX
 #endif
 
 // <y> USB Speed Limit
@@ -156,7 +156,7 @@
 // <1024=> Cached by 1024 bytes buffer (interrupt or isochronous EP)
 // <id> usb_ep2_I_CACHE
 #ifndef CONF_USB_EP2_I_CACHE
-#define CONF_USB_EP2_I_CACHE 0
+#define CONF_USB_EP2_I_CACHE 64
 #endif
 // </h>
 
@@ -308,7 +308,7 @@
 // <1024=> Cached by 1024 bytes buffer (interrupt or isochronous EP)
 // <id> usb_ep6_I_CACHE
 #ifndef CONF_USB_EP6_I_CACHE
-#define CONF_USB_EP6_I_CACHE 0
+#define CONF_USB_EP6_I_CACHE 64
 #endif
 // </h>
 

atmel-samd/asf4_conf/samd21/hpl_usb_config.h

@@ -28,6 +28,8 @@
 
 // <y> Max number of endpoints supported
 // <i> Limits the number of endpoints (described by EP address) can be used in app.
+// NOTE(tannewt): This not only limits the number of endpoints but also the
+// addresses. In other words, even if you use endpoint 6 you need to set this to 11.
 // <CONF_USB_N_1"> 1 (EP0 only)
 // <CONF_USB_N_2"> 2 (EP0 + 1 endpoint)
 // <CONF_USB_N_3"> 3 (EP0 + 2 endpoints)
@@ -39,7 +41,7 @@
 // <CONF_USB_D_N_EP_MAX"> Max possible (by "Max Endpoint Number" config)
 // <id> usbd_num_ep_sp
 #ifndef CONF_USB_D_NUM_EP_SP
-#define CONF_USB_D_NUM_EP_SP CONF_USB_N_4
+#define CONF_USB_D_NUM_EP_SP CONF_USB_D_N_EP_MAX
 #endif
 
 // </h>
@@ -60,7 +62,7 @@
 // <i> The number of physical endpoints - 1
 // <id> usbd_arch_max_ep_n
 #ifndef CONF_USB_D_MAX_EP_N
-#define CONF_USB_D_MAX_EP_N CONF_USB_N_2
+#define CONF_USB_D_MAX_EP_N CONF_USB_D_EP_N_MAX
 #endif
 
 // <y> USB Speed Limit
@@ -308,7 +310,7 @@
 // <1024=> Cached by 1024 bytes buffer (interrupt or isochronous EP)
 // <id> usb_ep6_I_CACHE
 #ifndef CONF_USB_EP6_I_CACHE
-#define CONF_USB_EP6_I_CACHE 0
+#define CONF_USB_EP6_I_CACHE 64
 #endif
 // </h>
 

atmel-samd/asf4_conf/samd51/hpl_usb_config.h

@@ -26,8 +26,9 @@
 #include "background.h"
 
 // #include "common-hal/audioio/AudioOut.h"
+#include "usb_mass_storage.h"
 
 void run_background_tasks(void) {
     // audioout_background();
-    // udi_msc_process_trans();
+    usb_msc_background();
 }

atmel-samd/background.c

@@ -172,17 +172,13 @@ bool internal_flash_write_block(const uint8_t *src, uint32_t block) {
             return false;
         }
         int32_t error_code;
-        // A block is formed by two rows of flash. We must erase each row
-        // before we write back to it.
         error_code = flash_erase(&internal_flash_desc,
                                  dest,
                                  FILESYSTEM_BLOCK_SIZE / flash_get_page_size(&internal_flash_desc));
         if (error_code != ERR_NONE) {
             return false;
         }
 
-        // A block is made up of multiple pages. Write each page
-        // sequentially.
         error_code = flash_append(&internal_flash_desc, dest, src, FILESYSTEM_BLOCK_SIZE);
         if (error_code != ERR_NONE) {
             return false;

atmel-samd/internal_flash.c

@@ -132,6 +132,10 @@ typedef long mp_off_t;
 #include "mpconfigboard.h"
 #include "include/sam.h"
 
+// ASF4 defines.
+#define CONF_USB_COMPOSITE_CDC_ACM_EN 1
+#define CONF_USB_COMPOSITE_MSC_EN 1
+
 #ifdef SAMD21
 #define CIRCUITPY_MCU_FAMILY samd21
 #define MICROPY_PY_SYS_PLATFORM                     "Atmel SAMD21"

atmel-samd/mpconfigport.h

@@ -65,6 +65,7 @@ void filesystem_init(bool create_allowed) {
 
         // set label
         f_setlabel(&vfs_fat->fatfs, "CIRCUITPY");
+        flash_flush();
     } else if (res != FR_OK) {
         return;
     }