circuitpython/ports/atmel-samd/usb_mass_storage.c

321 lines
10 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <string.h>
#include "usb_mass_storage.h"
#include "supervisor/shared/autoreload.h"
#include "hal/utils/include/err_codes.h"
#include "hal/utils/include/utils.h"
#include "usb/class/msc/device/mscdf.h"
#include "extmod/vfs.h"
#include "extmod/vfs_fat.h"
#include "lib/oofatfs/ff.h"
#include "lib/oofatfs/diskio.h"
#include "lib/oofatfs/ffconf.h"
#include "py/mpconfig.h"
#include "py/mphal.h"
#include "py/mpstate.h"
#include "py/misc.h"
// The root FS is always at the end of the list.
static fs_user_mount_t* get_vfs(int lun) {
// TODO(tannewt): Return the mount which matches the lun where 0 is the end
// and is counted in reverse.
if (lun > 0) {
return NULL;
}
mp_vfs_mount_t* current_mount = MP_STATE_VM(vfs_mount_table);
if (current_mount == NULL) {
return NULL;
}
while (current_mount->next != NULL) {
current_mount = current_mount->next;
}
return current_mount->obj;
}
/* Inquiry Information */
// This is designed to handle the common case where we have an internal file
// system and an optional SD card.
static uint8_t inquiry_info[2][36];
/* Capacities of Disk */
static uint8_t format_capa[2][8];
/**
* \brief Eject Disk
* \param[in] lun logic unit number
* \return Operation status.
*/
int32_t usb_msc_disk_eject(uint8_t lun) {
if (lun > 1) {
return ERR_NOT_FOUND;
}
fs_user_mount_t* current_mount = get_vfs(lun);
// Return ERR_NOT_READY if not ready, otherwise ERR_NONE.
if (current_mount == NULL) {
return ERR_NOT_FOUND;
}
// TODO(tannewt): Should we flush here?
return ERR_NONE;
}
/**
* \brief Inquiry whether Disk is writable. ERR_DENIED if it is not writable.
* ERR_NONE if it is. ERR_NOT_FOUND if its missing.
* \param[in] lun logic unit number
* \return Operation status.
*/
int32_t usb_msc_disk_is_writable(uint8_t lun) {
if (lun > 1) {
return ERR_NOT_FOUND;
}
fs_user_mount_t* vfs = get_vfs(lun);
if (vfs == NULL) {
return ERR_NOT_FOUND;
}
if (vfs->writeblocks[0] == MP_OBJ_NULL ||
(vfs->flags & FSUSER_USB_WRITABLE) == 0) {
return ERR_DENIED;
}
return ERR_NONE;
}
/**
* \brief Inquiry whether Disk is ready
* \param[in] lun logic unit number
* \return Operation status.
*/
int32_t usb_msc_disk_is_ready(uint8_t lun) {
if (lun > 1) {
return ERR_NOT_FOUND;
}
fs_user_mount_t* current_mount = get_vfs(lun);
if (current_mount == NULL) {
return ERR_NOT_FOUND;
}
return ERR_NONE;
}
/**
* \brief Callback invoked when inquiry data command received
* \param[in] lun logic unit number
* \return Operation status.
*/
uint8_t *usb_msc_inquiry_info(uint8_t lun) {
if (lun > 1) {
return NULL;
} else {
for (uint8_t i = 0; i < 36; i++) {
inquiry_info[lun][i] = 0;
}
inquiry_info[lun][0] = SCSI_INQ_PQ_CONNECTED | SCSI_INQ_DT_DIR_ACCESS;
// connected, direct access
inquiry_info[lun][1] = SCSI_INQ_RMB; // removable medium
inquiry_info[lun][2] = SCSI_INQ_VER_SPC; // SBC version of SCSI primary commands
inquiry_info[lun][3] = SCSI_INQ_RSP_SPC2;// SPC-2 response format
inquiry_info[lun][4] = 31; // 31 bytes following
return &inquiry_info[lun][0];
}
}
/**
* \brief Callback invoked when read format capacities command received
* \param[in] lun logic unit number
*/
uint8_t *usb_msc_get_capacity(uint8_t lun) {
if (lun > 1) {
return NULL;
} else {
fs_user_mount_t * vfs = get_vfs(lun);
uint32_t last_valid_sector = 0;
uint32_t sector_size = 0;
if (vfs == NULL ||
disk_ioctl(vfs, GET_SECTOR_COUNT, &last_valid_sector) != RES_OK ||
disk_ioctl(vfs, GET_SECTOR_SIZE, &sector_size) != RES_OK) {
return NULL;
}
// Subtract one from the sector count to get the last valid sector.
last_valid_sector--;
format_capa[lun][0] = (uint8_t)(last_valid_sector >> 24);
format_capa[lun][1] = (uint8_t)(last_valid_sector >> 16);
format_capa[lun][2] = (uint8_t)(last_valid_sector >> 8);
format_capa[lun][3] = (uint8_t)(last_valid_sector >> 0);
format_capa[lun][4] = (uint8_t)(sector_size >> 24);
format_capa[lun][5] = (uint8_t)(sector_size >> 16);
format_capa[lun][6] = (uint8_t)(sector_size >> 8);
format_capa[lun][7] = (uint8_t)(sector_size >> 0);
// 8 byte response. First 4 bytes are last block address. Second 4
// bytes are sector size.
return &format_capa[lun][0];
}
}
// USB transfer state.
volatile bool usb_busy;
volatile bool active_read;
volatile bool active_write;
volatile uint8_t active_lun;
volatile uint32_t active_addr;
volatile uint32_t active_nblocks;
volatile bool sector_loaded;
COMPILER_ALIGNED(4) uint8_t sector_buffer[512];
/**
* \brief Callback invoked when a new read blocks command received
* \param[in] lun logic unit number
* \param[in] addr start address of disk to be read
* \param[in] nblocks block amount to be read
* \return Operation status.
*/
int32_t usb_msc_new_read(uint8_t lun, uint32_t addr, uint32_t nblocks) {
if (lun > 1) {
return ERR_NOT_FOUND;
}
// Store transfer info so we can service it in the "background".
active_lun = lun;
active_addr = addr;
active_nblocks = nblocks;
active_read = true;
return ERR_NONE;
}
/**
* \brief Callback invoked when a new write blocks command received
* \param[in] lun logic unit number
* \param[in] addr start address of disk to be written
* \param[in] nblocks block amount to be written
* \return Operation status.
*/
int32_t usb_msc_new_write(uint8_t lun, uint32_t addr, uint32_t nblocks) {
if (lun > 1) {
return ERR_NOT_FOUND;
}
fs_user_mount_t * vfs = get_vfs(lun);
// This is used to determine the writeability of the disk from USB.
if (vfs == NULL) {
return ERR_NOT_FOUND;
}
if (vfs->writeblocks[0] == MP_OBJ_NULL ||
(vfs->flags & FSUSER_USB_WRITABLE) == 0) {
return ERR_DENIED;
}
// Store transfer info so we can service it in the "background".
active_lun = lun;
active_addr = addr;
active_nblocks = nblocks;
active_write = true;
sector_loaded = false;
// Return ERR_DENIED when the file system is read-only to the USB host.
return ERR_NONE;
}
/**
* \brief Callback invoked when a blocks transfer is done
* \param[in] lun logic unit number
* \return Operation status.
*/
int32_t usb_msc_xfer_done(uint8_t lun) {
if (lun > 1) {
return ERR_DENIED;
}
if (active_read) {
active_addr += 1;
active_nblocks--;
}
if (active_write) {
sector_loaded = true;
}
usb_busy = false;
return ERR_NONE;
}
// The start_read callback begins a read transaction which we accept but delay our response until the "main thread" calls usb_msc_background. Once it does, we read immediately from the drive into our cache and trigger the USB DMA to output the sector. Once the sector is transmitted, xfer_done will be called.
void usb_msc_background(void) {
if (active_read && !usb_busy) {
if (active_nblocks == 0) {
mscdf_xfer_blocks(false, NULL, 0);
active_read = false;
return;
}
fs_user_mount_t * vfs = get_vfs(active_lun);
disk_read(vfs, sector_buffer, active_addr, 1);
// TODO(tannewt): Check the read result.
mscdf_xfer_blocks(true, sector_buffer, 1);
usb_busy = true;
}
if (active_write && !usb_busy) {
if (sector_loaded) {
fs_user_mount_t * vfs = get_vfs(active_lun);
disk_write(vfs, sector_buffer, active_addr, 1);
// Since by getting here we assume the mount is read-only to
// MicroPython lets update the cached FatFs sector if its the one
// we just wrote.
#if _MAX_SS != _MIN_SS
if (vfs->ssize == FILESYSTEM_BLOCK_SIZE) {
#else
// The compiler can optimize this away.
if (_MAX_SS == FILESYSTEM_BLOCK_SIZE) {
#endif
if (active_addr == vfs->fatfs.winsect && active_addr > 0) {
memcpy(vfs->fatfs.win,
sector_buffer,
FILESYSTEM_BLOCK_SIZE);
}
}
sector_loaded = false;
active_addr += 1;
active_nblocks--;
}
// Load more blocks from USB if they are needed.
if (active_nblocks > 0) {
int32_t result = mscdf_xfer_blocks(false, sector_buffer, 1);
usb_busy = result != ERR_NONE;
} else {
mscdf_xfer_blocks(false, NULL, 0);
active_write = false;
// This write is complete, start the autoreload clock.
autoreload_start();
}
}
}