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tmk_keyboard/tool/mbed/mbed-sdk/libraries/fs/sd/SDFileSystem.cpp
Jun Wako 1fe4406f37 Squashed 'tmk_core/' changes from 7967731..b9e0ea0 
b9e0ea0 Merge commit '7fa9d8bdea3773d1195b04d98fcf27cf48ddd81d' as 'tool/mbed/mbed-sdk'
7fa9d8b Squashed 'tool/mbed/mbed-sdk/' content from commit 7c21ce5

git-subtree-dir: tmk_core
git-subtree-split: b9e0ea08cb940de20b3610ecdda18e9d8cd7c552
2015-04-24 16:26:14 +09:00

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/* mbed Microcontroller Library
* Copyright (c) 2006-2012 ARM Limited
*
* 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.
*/
/* Introduction
* ------------
* SD and MMC cards support a number of interfaces, but common to them all
* is one based on SPI. This is the one I'm implmenting because it means
* it is much more portable even though not so performant, and we already
* have the mbed SPI Interface!
*
* The main reference I'm using is Chapter 7, "SPI Mode" of:
* http://www.sdcard.org/developers/tech/sdcard/pls/Simplified_Physical_Layer_Spec.pdf
*
* SPI Startup
* -----------
* The SD card powers up in SD mode. The SPI interface mode is selected by
* asserting CS low and sending the reset command (CMD0). The card will
* respond with a (R1) response.
*
* CMD8 is optionally sent to determine the voltage range supported, and
* indirectly determine whether it is a version 1.x SD/non-SD card or
* version 2.x. I'll just ignore this for now.
*
* ACMD41 is repeatedly issued to initialise the card, until "in idle"
* (bit 0) of the R1 response goes to '0', indicating it is initialised.
*
* You should also indicate whether the host supports High Capicity cards,
* and check whether the card is high capacity - i'll also ignore this
*
* SPI Protocol
* ------------
* The SD SPI protocol is based on transactions made up of 8-bit words, with
* the host starting every bus transaction by asserting the CS signal low. The
* card always responds to commands, data blocks and errors.
*
* The protocol supports a CRC, but by default it is off (except for the
* first reset CMD0, where the CRC can just be pre-calculated, and CMD8)
* I'll leave the CRC off I think!
*
* Standard capacity cards have variable data block sizes, whereas High
* Capacity cards fix the size of data block to 512 bytes. I'll therefore
* just always use the Standard Capacity cards with a block size of 512 bytes.
* This is set with CMD16.
*
* You can read and write single blocks (CMD17, CMD25) or multiple blocks
* (CMD18, CMD25). For simplicity, I'll just use single block accesses. When
* the card gets a read command, it responds with a response token, and then
* a data token or an error.
*
* SPI Command Format
* ------------------
* Commands are 6-bytes long, containing the command, 32-bit argument, and CRC.
*
* +---------------+------------+------------+-----------+----------+--------------+
* | 01 | cmd[5:0] | arg[31:24] | arg[23:16] | arg[15:8] | arg[7:0] | crc[6:0] | 1 |
* +---------------+------------+------------+-----------+----------+--------------+
*
* As I'm not using CRC, I can fix that byte to what is needed for CMD0 (0x95)
*
* All Application Specific commands shall be preceded with APP_CMD (CMD55).
*
* SPI Response Format
* -------------------
* The main response format (R1) is a status byte (normally zero). Key flags:
* idle - 1 if the card is in an idle state/initialising
* cmd - 1 if an illegal command code was detected
*
* +-------------------------------------------------+
* R1 | 0 | arg | addr | seq | crc | cmd | erase | idle |
* +-------------------------------------------------+
*
* R1b is the same, except it is followed by a busy signal (zeros) until
* the first non-zero byte when it is ready again.
*
* Data Response Token
* -------------------
* Every data block written to the card is acknowledged by a byte
* response token
*
* +----------------------+
* | xxx | 0 | status | 1 |
* +----------------------+
* 010 - OK!
* 101 - CRC Error
* 110 - Write Error
*
* Single Block Read and Write
* ---------------------------
*
* Block transfers have a byte header, followed by the data, followed
* by a 16-bit CRC. In our case, the data will always be 512 bytes.
*
* +------+---------+---------+- - - -+---------+-----------+----------+
* | 0xFE | data[0] | data[1] | | data[n] | crc[15:8] | crc[7:0] |
* +------+---------+---------+- - - -+---------+-----------+----------+
*/
#include "SDFileSystem.h"
#include "mbed_debug.h"
#define SD_COMMAND_TIMEOUT 5000
#define SD_DBG 0
SDFileSystem::SDFileSystem(PinName mosi, PinName miso, PinName sclk, PinName cs, const char* name) :
FATFileSystem(name), _spi(mosi, miso, sclk), _cs(cs), _is_initialized(0) {
_cs = 1;
// Set default to 100kHz for initialisation and 1MHz for data transfer
_init_sck = 100000;
_transfer_sck = 1000000;
}
#define R1_IDLE_STATE (1 << 0)
#define R1_ERASE_RESET (1 << 1)
#define R1_ILLEGAL_COMMAND (1 << 2)
#define R1_COM_CRC_ERROR (1 << 3)
#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
#define R1_ADDRESS_ERROR (1 << 5)
#define R1_PARAMETER_ERROR (1 << 6)
// Types
// - v1.x Standard Capacity
// - v2.x Standard Capacity
// - v2.x High Capacity
// - Not recognised as an SD Card
#define SDCARD_FAIL 0
#define SDCARD_V1 1
#define SDCARD_V2 2
#define SDCARD_V2HC 3
int SDFileSystem::initialise_card() {
// Set to SCK for initialisation, and clock card with cs = 1
_spi.frequency(_init_sck);
_cs = 1;
for (int i = 0; i < 16; i++) {
_spi.write(0xFF);
}
// send CMD0, should return with all zeros except IDLE STATE set (bit 0)
if (_cmd(0, 0) != R1_IDLE_STATE) {
debug("No disk, or could not put SD card in to SPI idle state\n");
return SDCARD_FAIL;
}
// send CMD8 to determine whther it is ver 2.x
int r = _cmd8();
if (r == R1_IDLE_STATE) {
return initialise_card_v2();
} else if (r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
return initialise_card_v1();
} else {
debug("Not in idle state after sending CMD8 (not an SD card?)\n");
return SDCARD_FAIL;
}
}
int SDFileSystem::initialise_card_v1() {
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
_cmd(55, 0);
if (_cmd(41, 0) == 0) {
cdv = 512;
debug_if(SD_DBG, "\n\rInit: SEDCARD_V1\n\r");
return SDCARD_V1;
}
}
debug("Timeout waiting for v1.x card\n");
return SDCARD_FAIL;
}
int SDFileSystem::initialise_card_v2() {
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
wait_ms(50);
_cmd58();
_cmd(55, 0);
if (_cmd(41, 0x40000000) == 0) {
_cmd58();
debug_if(SD_DBG, "\n\rInit: SDCARD_V2\n\r");
cdv = 1;
return SDCARD_V2;
}
}
debug("Timeout waiting for v2.x card\n");
return SDCARD_FAIL;
}
int SDFileSystem::disk_initialize() {
_is_initialized = initialise_card();
if (_is_initialized == 0) {
debug("Fail to initialize card\n");
return 1;
}
debug_if(SD_DBG, "init card = %d\n", _is_initialized);
_sectors = _sd_sectors();
// Set block length to 512 (CMD16)
if (_cmd(16, 512) != 0) {
debug("Set 512-byte block timed out\n");
return 1;
}
// Set SCK for data transfer
_spi.frequency(_transfer_sck);
return 0;
}
int SDFileSystem::disk_write(const uint8_t* buffer, uint64_t block_number, uint8_t count) {
if (!_is_initialized) {
return -1;
}
for (uint64_t b = block_number; b < block_number + count; b++) {
// set write address for single block (CMD24)
if (_cmd(24, b * cdv) != 0) {
return 1;
}
// send the data block
_write(buffer, 512);
buffer += 512;
}
return 0;
}
int SDFileSystem::disk_read(uint8_t* buffer, uint64_t block_number, uint8_t count) {
if (!_is_initialized) {
return -1;
}
for (uint64_t b = block_number; b < block_number + count; b++) {
// set read address for single block (CMD17)
if (_cmd(17, b * cdv) != 0) {
return 1;
}
// receive the data
_read(buffer, 512);
buffer += 512;
}
return 0;
}
int SDFileSystem::disk_status() {
// FATFileSystem::disk_status() returns 0 when initialized
if (_is_initialized) {
return 0;
} else {
return 1;
}
}
int SDFileSystem::disk_sync() { return 0; }
uint64_t SDFileSystem::disk_sectors() { return _sectors; }
// PRIVATE FUNCTIONS
int SDFileSystem::_cmd(int cmd, int arg) {
_cs = 0;
// send a command
_spi.write(0x40 | cmd);
_spi.write(arg >> 24);
_spi.write(arg >> 16);
_spi.write(arg >> 8);
_spi.write(arg >> 0);
_spi.write(0x95);
// wait for the repsonse (response[7] == 0)
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
int response = _spi.write(0xFF);
if (!(response & 0x80)) {
_cs = 1;
_spi.write(0xFF);
return response;
}
}
_cs = 1;
_spi.write(0xFF);
return -1; // timeout
}
int SDFileSystem::_cmdx(int cmd, int arg) {
_cs = 0;
// send a command
_spi.write(0x40 | cmd);
_spi.write(arg >> 24);
_spi.write(arg >> 16);
_spi.write(arg >> 8);
_spi.write(arg >> 0);
_spi.write(0x95);
// wait for the repsonse (response[7] == 0)
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
int response = _spi.write(0xFF);
if (!(response & 0x80)) {
return response;
}
}
_cs = 1;
_spi.write(0xFF);
return -1; // timeout
}
int SDFileSystem::_cmd58() {
_cs = 0;
int arg = 0;
// send a command
_spi.write(0x40 | 58);
_spi.write(arg >> 24);
_spi.write(arg >> 16);
_spi.write(arg >> 8);
_spi.write(arg >> 0);
_spi.write(0x95);
// wait for the repsonse (response[7] == 0)
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
int response = _spi.write(0xFF);
if (!(response & 0x80)) {
int ocr = _spi.write(0xFF) << 24;
ocr |= _spi.write(0xFF) << 16;
ocr |= _spi.write(0xFF) << 8;
ocr |= _spi.write(0xFF) << 0;
_cs = 1;
_spi.write(0xFF);
return response;
}
}
_cs = 1;
_spi.write(0xFF);
return -1; // timeout
}
int SDFileSystem::_cmd8() {
_cs = 0;
// send a command
_spi.write(0x40 | 8); // CMD8
_spi.write(0x00); // reserved
_spi.write(0x00); // reserved
_spi.write(0x01); // 3.3v
_spi.write(0xAA); // check pattern
_spi.write(0x87); // crc
// wait for the repsonse (response[7] == 0)
for (int i = 0; i < SD_COMMAND_TIMEOUT * 1000; i++) {
char response[5];
response[0] = _spi.write(0xFF);
if (!(response[0] & 0x80)) {
for (int j = 1; j < 5; j++) {
response[i] = _spi.write(0xFF);
}
_cs = 1;
_spi.write(0xFF);
return response[0];
}
}
_cs = 1;
_spi.write(0xFF);
return -1; // timeout
}
int SDFileSystem::_read(uint8_t *buffer, uint32_t length) {
_cs = 0;
// read until start byte (0xFF)
while (_spi.write(0xFF) != 0xFE);
// read data
for (uint32_t i = 0; i < length; i++) {
buffer[i] = _spi.write(0xFF);
}
_spi.write(0xFF); // checksum
_spi.write(0xFF);
_cs = 1;
_spi.write(0xFF);
return 0;
}
int SDFileSystem::_write(const uint8_t*buffer, uint32_t length) {
_cs = 0;
// indicate start of block
_spi.write(0xFE);
// write the data
for (uint32_t i = 0; i < length; i++) {
_spi.write(buffer[i]);
}
// write the checksum
_spi.write(0xFF);
_spi.write(0xFF);
// check the response token
if ((_spi.write(0xFF) & 0x1F) != 0x05) {
_cs = 1;
_spi.write(0xFF);
return 1;
}
// wait for write to finish
while (_spi.write(0xFF) == 0);
_cs = 1;
_spi.write(0xFF);
return 0;
}
static uint32_t ext_bits(unsigned char *data, int msb, int lsb) {
uint32_t bits = 0;
uint32_t size = 1 + msb - lsb;
for (uint32_t i = 0; i < size; i++) {
uint32_t position = lsb + i;
uint32_t byte = 15 - (position >> 3);
uint32_t bit = position & 0x7;
uint32_t value = (data[byte] >> bit) & 1;
bits |= value << i;
}
return bits;
}
uint64_t SDFileSystem::_sd_sectors() {
uint32_t c_size, c_size_mult, read_bl_len;
uint32_t block_len, mult, blocknr, capacity;
uint32_t hc_c_size;
uint64_t blocks;
// CMD9, Response R2 (R1 byte + 16-byte block read)
if (_cmdx(9, 0) != 0) {
debug("Didn't get a response from the disk\n");
return 0;
}
uint8_t csd[16];
if (_read(csd, 16) != 0) {
debug("Couldn't read csd response from disk\n");
return 0;
}
// csd_structure : csd[127:126]
// c_size : csd[73:62]
// c_size_mult : csd[49:47]
// read_bl_len : csd[83:80] - the *maximum* read block length
int csd_structure = ext_bits(csd, 127, 126);
switch (csd_structure) {
case 0:
cdv = 512;
c_size = ext_bits(csd, 73, 62);
c_size_mult = ext_bits(csd, 49, 47);
read_bl_len = ext_bits(csd, 83, 80);
block_len = 1 << read_bl_len;
mult = 1 << (c_size_mult + 2);
blocknr = (c_size + 1) * mult;
capacity = blocknr * block_len;
blocks = capacity / 512;
debug_if(SD_DBG, "\n\rSDCard\n\rc_size: %d \n\rcapacity: %ld \n\rsectors: %lld\n\r", c_size, capacity, blocks);
break;
case 1:
cdv = 1;
hc_c_size = ext_bits(csd, 63, 48);
blocks = (hc_c_size+1)*1024;
debug_if(SD_DBG, "\n\rSDHC Card \n\rhc_c_size: %d\n\rcapacity: %lld \n\rsectors: %lld\n\r", hc_c_size, blocks*512, blocks);
break;
default:
debug("CSD struct unsupported\r\n");
return 0;
};
return blocks;
}
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