/* * This file is part of the Micro Python project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2013, 2014 Damien P. George * * 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 #include #include "asf/sam0/drivers/sercom/spi/spi.h" #include "py/gc.h" #include "py/obj.h" #include "py/runtime.h" #include "lib/fatfs/ff.h" #include "extmod/fsusermount.h" #include "spi_flash.h" #define SPI_FLASH_PART1_START_BLOCK (0x1) #define NO_SECTOR_LOADED 0xFFFFFFFF #define CMD_READ_JEDEC_ID 0x9f #define CMD_READ_DATA 0x03 #define CMD_SECTOR_ERASE 0x20 // #define CMD_SECTOR_ERASE CMD_READ_JEDEC_ID #define CMD_ENABLE_WRITE 0x06 #define CMD_PAGE_PROGRAM 0x02 // #define CMD_PAGE_PROGRAM CMD_READ_JEDEC_ID #define CMD_READ_STATUS 0x05 static bool spi_flash_is_initialised = false; struct spi_module spi_flash_instance; // The total size of the flash. static uint32_t flash_size; // The erase sector size. static uint32_t sector_size; // The page size. Its the maximum number of bytes that can be written at once. static uint32_t page_size; // The currently cached sector in the cache, ram or flash based. static uint32_t current_sector; // Track which blocks (up to 32) in the current sector currently live in the // cache. static uint32_t dirty_mask; // We use this when we can allocate the whole cache in RAM. static uint8_t** ram_cache; // Address of the scratch flash sector. #define SCRATCH_SECTOR (flash_size - sector_size) // Enable the flash over SPI. static void flash_enable() { port_pin_set_output_level(SPI_FLASH_CS, false); } // Disable the flash over SPI. static void flash_disable() { port_pin_set_output_level(SPI_FLASH_CS, true); } // Wait until both the write enable and write in progress bits have cleared. static bool wait_for_flash_ready() { uint8_t status_request[2] = {CMD_READ_STATUS, 0x00}; uint8_t response[2] = {0x00, 0x01}; enum status_code status = STATUS_OK; // Both the write enable and write in progress bits should be low. while (status == STATUS_OK && ((response[1] & 0x1) == 1 || (response[1] & 0x2) == 2)) { flash_enable(); status = spi_transceive_buffer_wait(&spi_flash_instance, status_request, response, 2); flash_disable(); } return status == STATUS_OK; } // Turn on the write enable bit so we can program and erase the flash. static bool write_enable() { flash_enable(); uint8_t command = CMD_ENABLE_WRITE; enum status_code status = spi_write_buffer_wait(&spi_flash_instance, &command, 1); flash_disable(); return status == STATUS_OK; } // Pack the low 24 bits of the address into a uint8_t array. static void address_to_bytes(uint32_t address, uint8_t* bytes) { bytes[0] = (address >> 16) & 0xff; bytes[1] = (address >> 8) & 0xff; bytes[2] = address & 0xff; } // Read data_length's worth of bytes starting at address into data. static bool read_flash(uint32_t address, uint8_t* data, uint32_t data_length) { wait_for_flash_ready(); enum status_code status; // We can read as much as we want sequentially. uint8_t read_request[4] = {CMD_READ_DATA, 0x00, 0x00, 0x00}; address_to_bytes(address, read_request + 1); flash_enable(); status = spi_write_buffer_wait(&spi_flash_instance, read_request, 4); if (status == STATUS_OK) { status = spi_read_buffer_wait(&spi_flash_instance, data, data_length, 0x00); } flash_disable(); return status == STATUS_OK; } // Writes data_length's worth of bytes starting at address from data. Assumes // that the sector that address resides in has already been erased. So make sure // to run erase_sector. static bool write_flash(uint32_t address, const uint8_t* data, uint32_t data_length) { if (page_size == 0) { return false; } for (uint32_t bytes_written = 0; bytes_written < data_length; bytes_written += page_size) { if (!wait_for_flash_ready() || !write_enable()) { return false; } flash_enable(); uint8_t command[4] = {CMD_PAGE_PROGRAM, 0x00, 0x00, 0x00}; address_to_bytes(address + bytes_written, command + 1); enum status_code status; status = spi_write_buffer_wait(&spi_flash_instance, command, 4); if (status == STATUS_OK) { status = spi_write_buffer_wait(&spi_flash_instance, data + bytes_written, page_size); } flash_disable(); if (status != STATUS_OK) { return false; } } return true; } // Erases the given sector. Make sure you copied all of the data out of it you // need! Also note, sector_address is really 24 bits. static bool erase_sector(uint32_t sector_address) { // Before we erase the sector we need to wait for any writes to finish and // and then enable the write again. if (!wait_for_flash_ready() || !write_enable()) { return false; } uint8_t erase_request[4] = {CMD_SECTOR_ERASE, 0x00, 0x00, 0x00}; address_to_bytes(sector_address, erase_request + 1); flash_enable(); enum status_code status = spi_write_buffer_wait(&spi_flash_instance, erase_request, 4); flash_disable(); return status == STATUS_OK; } // Sector is really 24 bits. static bool copy_block(uint32_t src_address, uint32_t dest_address) { // Copy page by page to minimize RAM buffer. uint8_t buffer[page_size]; for (int i = 0; i < FLASH_BLOCK_SIZE / page_size; i++) { if (!read_flash(src_address + i * page_size, buffer, page_size)) { return false; } if (!write_flash(dest_address + i * page_size, buffer, page_size)) { return false; } } return true; } void spi_flash_init(void) { if (!spi_flash_is_initialised) { struct spi_config config_spi_master; spi_get_config_defaults(&config_spi_master); config_spi_master.mux_setting = SPI_FLASH_MUX_SETTING; config_spi_master.pinmux_pad0 = SPI_FLASH_PAD0_PINMUX; config_spi_master.pinmux_pad1 = SPI_FLASH_PAD1_PINMUX; config_spi_master.pinmux_pad2 = SPI_FLASH_PAD2_PINMUX; config_spi_master.pinmux_pad3 = SPI_FLASH_PAD3_PINMUX; config_spi_master.mode_specific.master.baudrate = SPI_FLASH_BAUDRATE; spi_init(&spi_flash_instance, SPI_FLASH_SERCOM, &config_spi_master); spi_enable(&spi_flash_instance); // Manage chip select ourselves. struct port_config pin_conf; port_get_config_defaults(&pin_conf); pin_conf.direction = PORT_PIN_DIR_OUTPUT; port_pin_set_config(SPI_FLASH_CS, &pin_conf); flash_disable(); // Activity LED for flash writes. #ifdef MICROPY_HW_LED_MSC port_pin_set_config(MICROPY_HW_LED_MSC, &pin_conf); port_pin_set_output_level(MICROPY_HW_LED_MSC, false); #endif uint8_t jedec_id_request[4] = {CMD_READ_JEDEC_ID, 0x00, 0x00, 0x00}; uint8_t response[4] = {0x00, 0x00, 0x00, 0x00}; flash_enable(); volatile enum status_code status = spi_transceive_buffer_wait(&spi_flash_instance, jedec_id_request, response, 4); flash_disable(); (void) status; if (response[1] == 0x01 && response[2] == 0x40 && response[3] == 0x15) { flash_size = 1 << 21; // 2 MiB sector_size = 1 << 12; // 4 KiB page_size = 256; // 256 bytes } else { // Unknown flash chip! flash_size = 0; } current_sector = NO_SECTOR_LOADED; dirty_mask = 0; ram_cache = NULL; spi_flash_is_initialised = true; } } // The size of each individual block. uint32_t spi_flash_get_block_size(void) { return FLASH_BLOCK_SIZE; } // The total number of available blocks. uint32_t spi_flash_get_block_count(void) { // We subtract one erase sector size because we may use it as a staging area // for writes. return SPI_FLASH_PART1_START_BLOCK + (flash_size - sector_size) / FLASH_BLOCK_SIZE; } // Flush the cache that was written to the scratch portion of flash. Only used // when ram is tight. static bool flush_scratch_flash() { // First, copy out any blocks that we haven't touched from the sector we've // cached. bool copy_to_scratch_ok = true; for (int i = 0; i < sector_size / FLASH_BLOCK_SIZE; i++) { if ((dirty_mask & (1 << i)) == 0) { copy_to_scratch_ok = copy_to_scratch_ok && copy_block(current_sector + i * FLASH_BLOCK_SIZE, SCRATCH_SECTOR + i * FLASH_BLOCK_SIZE); } } if (!copy_to_scratch_ok) { // TODO(tannewt): Do more here. We opted to not erase and copy bad data // in. We still risk losing the data written to the scratch sector. return false; } // Second, erase the current sector. erase_sector(current_sector); // Finally, copy the new version into it. for (int i = 0; i < sector_size / FLASH_BLOCK_SIZE; i++) { copy_block(SCRATCH_SECTOR + i * FLASH_BLOCK_SIZE, current_sector + i * FLASH_BLOCK_SIZE); } return true; } // Attempts to allocate a new set of page buffers for caching a full sector in // ram. Each page is allocated separately so that the GC doesn't need to provide // one huge block. We can free it as we write if we want to also. static bool allocate_ram_cache() { uint8_t blocks_per_sector = sector_size / FLASH_BLOCK_SIZE; uint8_t pages_per_block = FLASH_BLOCK_SIZE / page_size; ram_cache = gc_alloc(blocks_per_sector * pages_per_block * sizeof(uint32_t), false); if (ram_cache == NULL) { return false; } // Declare i and j outside the loops in case we fail to allocate everything // we need. In that case we'll give it back. int i = 0; int j = 0; bool success = true; for (i = 0; i < sector_size / FLASH_BLOCK_SIZE; i++) { for (int j = 0; j < pages_per_block; j++) { uint8_t *page_cache = gc_alloc(page_size, false); if (page_cache == NULL) { success = false; break; } ram_cache[i * pages_per_block + j] = page_cache; } if (!success) { break; } } // We couldn't allocate enough so give back what we got. if (!success) { for (; i >= 0; i--) { for (; j >= 0; j--) { gc_free(ram_cache[i * pages_per_block + j]); } j = pages_per_block - 1; } gc_free(ram_cache); ram_cache = NULL; } return success; } // Flush the cached sector from ram onto the flash. We'll free the cache unless // keep_cache is true. static bool flush_ram_cache(bool keep_cache) { // First, copy out any blocks that we haven't touched from the sector // we've cached. If we don't do this we'll erase the data during the sector // erase below. bool copy_to_ram_ok = true; uint8_t pages_per_block = FLASH_BLOCK_SIZE / page_size; for (int i = 0; i < sector_size / FLASH_BLOCK_SIZE; i++) { if ((dirty_mask & (1 << i)) == 0) { for (int j = 0; j < pages_per_block; j++) { copy_to_ram_ok = read_flash( current_sector + (i * pages_per_block + j) * page_size, ram_cache[i * pages_per_block + j], page_size); if (!copy_to_ram_ok) { break; } } } if (!copy_to_ram_ok) { break; } } if (!copy_to_ram_ok) { return false; } // Second, erase the current sector. erase_sector(current_sector); // Lastly, write all the data in ram that we've cached. for (int i = 0; i < sector_size / FLASH_BLOCK_SIZE; i++) { for (int j = 0; j < pages_per_block; j++) { write_flash(current_sector + (i * pages_per_block + j) * page_size, ram_cache[i * pages_per_block + j], page_size); if (!keep_cache) { gc_free(ram_cache[i * pages_per_block + j]); } } } // We're done with the cache for now so give it back. if (!keep_cache) { gc_free(ram_cache); ram_cache = NULL; } return true; } // Delegates to the correct flash flush method depending on the existing cache. static void spi_flash_flush_keep_cache(bool keep_cache) { if (current_sector == NO_SECTOR_LOADED) { return; } #ifdef MICROPY_HW_LED_MSC port_pin_set_output_level(MICROPY_HW_LED_MSC, true); #endif // If we've cached to the flash itself flush from there. if (ram_cache == NULL) { flush_scratch_flash(); } else { flush_ram_cache(keep_cache); } current_sector = NO_SECTOR_LOADED; #ifdef MICROPY_HW_LED_MSC port_pin_set_output_level(MICROPY_HW_LED_MSC, false); #endif } // External flash function used. If called externally we assume we won't need // the cache after. void spi_flash_flush(void) { spi_flash_flush_keep_cache(false); } // Builds a partition entry for the MBR. static void build_partition(uint8_t *buf, int boot, int type, uint32_t start_block, uint32_t num_blocks) { buf[0] = boot; if (num_blocks == 0) { buf[1] = 0; buf[2] = 0; buf[3] = 0; } else { buf[1] = 0xff; buf[2] = 0xff; buf[3] = 0xff; } buf[4] = type; if (num_blocks == 0) { buf[5] = 0; buf[6] = 0; buf[7] = 0; } else { buf[5] = 0xff; buf[6] = 0xff; buf[7] = 0xff; } buf[8] = start_block; buf[9] = start_block >> 8; buf[10] = start_block >> 16; buf[11] = start_block >> 24; buf[12] = num_blocks; buf[13] = num_blocks >> 8; buf[14] = num_blocks >> 16; buf[15] = num_blocks >> 24; } static uint32_t convert_block_to_flash_addr(uint32_t block) { if (SPI_FLASH_PART1_START_BLOCK <= block && block < spi_flash_get_block_count()) { // a block in partition 1 block -= SPI_FLASH_PART1_START_BLOCK; return block * FLASH_BLOCK_SIZE; } // bad block return -1; } bool spi_flash_read_block(uint8_t *dest, uint32_t block) { if (block == 0) { // Fake the MBR so we can decide on our own partition table for (int i = 0; i < 446; i++) { dest[i] = 0; } build_partition(dest + 446, 0, 0x01 /* FAT12 */, SPI_FLASH_PART1_START_BLOCK, spi_flash_get_block_count() - SPI_FLASH_PART1_START_BLOCK); build_partition(dest + 462, 0, 0, 0, 0); build_partition(dest + 478, 0, 0, 0, 0); build_partition(dest + 494, 0, 0, 0, 0); dest[510] = 0x55; dest[511] = 0xaa; return true; } else if (block < SPI_FLASH_PART1_START_BLOCK) { memset(dest, 0, FLASH_BLOCK_SIZE); return true; } else { // Non-MBR block, get data from flash memory. uint32_t address = convert_block_to_flash_addr(block); if (address == -1) { // bad block number return false; } // Mask out the lower bits that designate the address within the sector. uint32_t this_sector = address & (~(sector_size - 1)); uint8_t block_index = (address / FLASH_BLOCK_SIZE) % (sector_size / FLASH_BLOCK_SIZE); uint8_t mask = 1 << (block_index); // We're reading from the currently cached sector. if (current_sector == this_sector && (mask & dirty_mask) > 0) { if (ram_cache != NULL) { uint8_t pages_per_block = FLASH_BLOCK_SIZE / page_size; for (int i = 0; i < pages_per_block; i++) { memcpy(dest + i * page_size, ram_cache[block_index * pages_per_block + i], page_size); } return true; } else { uint32_t scratch_address = SCRATCH_SECTOR + block_index * FLASH_BLOCK_SIZE; return read_flash(scratch_address, dest, FLASH_BLOCK_SIZE); } } return read_flash(address, dest, FLASH_BLOCK_SIZE); } } bool spi_flash_write_block(const uint8_t *data, uint32_t block) { if (block < SPI_FLASH_PART1_START_BLOCK) { // Fake writing below the flash partition. return true; } else { // Non-MBR block, copy to cache uint32_t address = convert_block_to_flash_addr(block); if (address == -1) { // bad block number return false; } // Wait for any previous writes to finish. wait_for_flash_ready(); // Mask out the lower bits that designate the address within the sector. uint32_t this_sector = address & (~(sector_size - 1)); uint8_t block_index = (address / FLASH_BLOCK_SIZE) % (sector_size / FLASH_BLOCK_SIZE); uint8_t mask = 1 << (block_index); // Flush the cache if we're moving onto a sector our we're writing the // same block again. if (current_sector != this_sector || (mask & dirty_mask) > 0) { if (current_sector != NO_SECTOR_LOADED) { spi_flash_flush_keep_cache(true); } if (ram_cache == NULL && !allocate_ram_cache()) { erase_sector(SCRATCH_SECTOR); wait_for_flash_ready(); } current_sector = this_sector; dirty_mask = 0; } dirty_mask |= mask; // Copy the block to the appropriate cache. if (ram_cache != NULL) { uint8_t pages_per_block = FLASH_BLOCK_SIZE / page_size; for (int i = 0; i < pages_per_block; i++) { memcpy(ram_cache[block_index * pages_per_block + i], data + i * page_size, page_size); } return true; } else { uint32_t scratch_address = SCRATCH_SECTOR + block_index * FLASH_BLOCK_SIZE; return write_flash(scratch_address, data, FLASH_BLOCK_SIZE); } } } mp_uint_t spi_flash_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) { for (size_t i = 0; i < num_blocks; i++) { if (!spi_flash_read_block(dest + i * FLASH_BLOCK_SIZE, block_num + i)) { return 1; // error } } return 0; // success } mp_uint_t spi_flash_write_blocks(const uint8_t *src, uint32_t block_num, uint32_t num_blocks) { for (size_t i = 0; i < num_blocks; i++) { if (!spi_flash_write_block(src + i * FLASH_BLOCK_SIZE, block_num + i)) { return 1; // error } } return 0; // success } /******************************************************************************/ // MicroPython bindings // // Expose the flash as an object with the block protocol. // there is a singleton Flash object STATIC const mp_obj_base_t spi_flash_obj = {&spi_flash_type}; STATIC mp_obj_t spi_flash_obj_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) { // check arguments mp_arg_check_num(n_args, n_kw, 0, 0, false); // return singleton object return (mp_obj_t)&spi_flash_obj; } STATIC mp_obj_t spi_flash_obj_readblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) { mp_buffer_info_t bufinfo; mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_WRITE); mp_uint_t ret = spi_flash_read_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FLASH_BLOCK_SIZE); return MP_OBJ_NEW_SMALL_INT(ret); } STATIC MP_DEFINE_CONST_FUN_OBJ_3(spi_flash_obj_readblocks_obj, spi_flash_obj_readblocks); STATIC mp_obj_t spi_flash_obj_writeblocks(mp_obj_t self, mp_obj_t block_num, mp_obj_t buf) { mp_buffer_info_t bufinfo; mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ); mp_uint_t ret = spi_flash_write_blocks(bufinfo.buf, mp_obj_get_int(block_num), bufinfo.len / FLASH_BLOCK_SIZE); return MP_OBJ_NEW_SMALL_INT(ret); } STATIC MP_DEFINE_CONST_FUN_OBJ_3(spi_flash_obj_writeblocks_obj, spi_flash_obj_writeblocks); STATIC mp_obj_t spi_flash_obj_ioctl(mp_obj_t self, mp_obj_t cmd_in, mp_obj_t arg_in) { mp_int_t cmd = mp_obj_get_int(cmd_in); switch (cmd) { case BP_IOCTL_INIT: spi_flash_init(); return MP_OBJ_NEW_SMALL_INT(0); case BP_IOCTL_DEINIT: spi_flash_flush(); return MP_OBJ_NEW_SMALL_INT(0); // TODO properly case BP_IOCTL_SYNC: spi_flash_flush(); return MP_OBJ_NEW_SMALL_INT(0); case BP_IOCTL_SEC_COUNT: return MP_OBJ_NEW_SMALL_INT(spi_flash_get_block_count()); case BP_IOCTL_SEC_SIZE: return MP_OBJ_NEW_SMALL_INT(spi_flash_get_block_size()); default: return mp_const_none; } } STATIC MP_DEFINE_CONST_FUN_OBJ_3(spi_flash_obj_ioctl_obj, spi_flash_obj_ioctl); STATIC const mp_map_elem_t spi_flash_obj_locals_dict_table[] = { { MP_OBJ_NEW_QSTR(MP_QSTR_readblocks), (mp_obj_t)&spi_flash_obj_readblocks_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_writeblocks), (mp_obj_t)&spi_flash_obj_writeblocks_obj }, { MP_OBJ_NEW_QSTR(MP_QSTR_ioctl), (mp_obj_t)&spi_flash_obj_ioctl_obj }, }; STATIC MP_DEFINE_CONST_DICT(spi_flash_obj_locals_dict, spi_flash_obj_locals_dict_table); const mp_obj_type_t spi_flash_type = { { &mp_type_type }, .name = MP_QSTR_SPIFlash, .make_new = spi_flash_obj_make_new, .locals_dict = (mp_obj_t)&spi_flash_obj_locals_dict, }; void flash_init_vfs(fs_user_mount_t *vfs) { vfs->flags |= FSUSER_NATIVE | FSUSER_HAVE_IOCTL | FSUSER_USB_WRITEABLE; vfs->readblocks[0] = (mp_obj_t)&spi_flash_obj_readblocks_obj; vfs->readblocks[1] = (mp_obj_t)&spi_flash_obj; vfs->readblocks[2] = (mp_obj_t)spi_flash_read_blocks; // native version vfs->writeblocks[0] = (mp_obj_t)&spi_flash_obj_writeblocks_obj; vfs->writeblocks[1] = (mp_obj_t)&spi_flash_obj; vfs->writeblocks[2] = (mp_obj_t)spi_flash_write_blocks; // native version vfs->u.ioctl[0] = (mp_obj_t)&spi_flash_obj_ioctl_obj; vfs->u.ioctl[1] = (mp_obj_t)&spi_flash_obj; }