Mathew Swabey
Updated
Diff: SDBlockDevice.cpp
- Revision:
- 0:19febeae2548
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/SDBlockDevice.cpp Sat Jan 05 15:02:34 2019 +0000
@@ -0,0 +1,1013 @@
+/* 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. Since we already have the mbed SPI Interface, it will
+ * be used for SD cards.
+ *
+ * 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 start-up procedure is complicated
+ * by the requirement to support older SDCards in a backwards compatible
+ * way with the new higher capacity variants SDHC and SDHC.
+ *
+ * The following figures from the specification with associated text describe
+ * the SPI mode initialisation process:
+ * - Figure 7-1: SD Memory Card State Diagram (SPI mode)
+ * - Figure 7-2: SPI Mode Initialization Flow
+ *
+ * Firstly, a low initial clock should be selected (in the range of 100-
+ * 400kHZ). After initialisation has been completed, the switch to a
+ * higher clock speed can be made (e.g. 1MHz). Newer cards will support
+ * higher speeds than the default _transfer_sck defined here.
+ *
+ * Next, note the following from the SDCard specification (note to
+ * Figure 7-1):
+ *
+ * In any of the cases CMD1 is not recommended because it may be difficult for the host
+ * to distinguish between MultiMediaCard and SD Memory Card
+ *
+ * Hence CMD1 is not used for the initialisation sequence.
+ *
+ * The SPI interface mode is selected by asserting CS low and sending the
+ * reset command (CMD0). The card will respond with a (R1) response.
+ * In practice many cards initially respond with 0xff or invalid data
+ * which is ignored. Data is read until a valid response is received
+ * or the number of re-reads has exceeded a maximim count. If a valid
+ * response is not received then the CMD0 can be retried. This
+ * has been found to successfully initialise cards where the SPI master
+ * (on MCU) has been reset but the SDCard has not, so the first
+ * CMD0 may be lost.
+ *
+ * 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] |
+ * +------+---------+---------+- - - -+---------+-----------+----------+
+ */
+
+/* If the target has no SPI support then SDCard is not supported */
+#ifdef DEVICE_SPI
+
+#include "SDBlockDevice.h"
+#include "mbed_debug.h"
+#include <errno.h>
+
+/* Required version: 5.6.1 and above */
+#ifdef MBED_MAJOR_VERSION
+#if (MBED_VERSION < MBED_ENCODE_VERSION(5,6,1))
+#error "Incompatible mbed-os version detected! Required 5.5.4 and above"
+#endif
+#else
+#warning "mbed-os version 5.6.1 or above required"
+#endif
+
+#define SD_COMMAND_TIMEOUT 5000 /*!< Timeout in ms for response */
+#define SD_CMD0_GO_IDLE_STATE_RETRIES 5 /*!< Number of retries for sending CMDO */
+#define SD_DBG 0 /*!< 1 - Enable debugging */
+#define SD_CMD_TRACE 0 /*!< 1 - Enable SD command tracing */
+
+#define SD_BLOCK_DEVICE_ERROR_WOULD_BLOCK -5001 /*!< operation would block */
+#define SD_BLOCK_DEVICE_ERROR_UNSUPPORTED -5002 /*!< unsupported operation */
+#define SD_BLOCK_DEVICE_ERROR_PARAMETER -5003 /*!< invalid parameter */
+#define SD_BLOCK_DEVICE_ERROR_NO_INIT -5004 /*!< uninitialized */
+#define SD_BLOCK_DEVICE_ERROR_NO_DEVICE -5005 /*!< device is missing or not connected */
+#define SD_BLOCK_DEVICE_ERROR_WRITE_PROTECTED -5006 /*!< write protected */
+#define SD_BLOCK_DEVICE_ERROR_UNUSABLE -5007 /*!< unusable card */
+#define SD_BLOCK_DEVICE_ERROR_NO_RESPONSE -5008 /*!< No response from device */
+#define SD_BLOCK_DEVICE_ERROR_CRC -5009 /*!< CRC error */
+#define SD_BLOCK_DEVICE_ERROR_ERASE -5010 /*!< Erase error: reset/sequence */
+#define SD_BLOCK_DEVICE_ERROR_WRITE -5011 /*!< SPI Write error: !SPI_DATA_ACCEPTED */
+
+#define BLOCK_SIZE_HC 512 /*!< Block size supported for SD card is 512 bytes */
+#define WRITE_BL_PARTIAL 0 /*!< Partial block write - Not supported */
+#define CRC_SUPPORT 0 /*!< CRC - Not supported */
+#define SPI_CMD(x) (0x40 | (x & 0x3f))
+
+/* R1 Response Format */
+#define R1_NO_RESPONSE (0xFF)
+#define R1_RESPONSE_RECV (0x80)
+#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
+#define SDCARD_NONE 0 /**< No card is present */
+#define SDCARD_V1 1 /**< v1.x Standard Capacity */
+#define SDCARD_V2 2 /**< v2.x Standard capacity SD card */
+#define SDCARD_V2HC 3 /**< v2.x High capacity SD card */
+#define CARD_UNKNOWN 4 /**< Unknown or unsupported card */
+
+/* SIZE in Bytes */
+#define PACKET_SIZE 6 /*!< SD Packet size CMD+ARG+CRC */
+#define R1_RESPONSE_SIZE 1 /*!< Size of R1 response */
+#define R2_RESPONSE_SIZE 2 /*!< Size of R2 response */
+#define R3_R7_RESPONSE_SIZE 5 /*!< Size of R3/R7 response */
+
+/* R1b Response */
+#define DEVICE_BUSY (0x00)
+
+/* R2 Response Format */
+#define R2_CARD_LOCKED (1 << 0)
+#define R2_CMD_FAILED (1 << 1)
+#define R2_ERROR (1 << 2)
+#define R2_CC_ERROR (1 << 3)
+#define R2_CC_FAILED (1 << 4)
+#define R2_WP_VIOLATION (1 << 5)
+#define R2_ERASE_PARAM (1 << 6)
+#define R2_OUT_OF_RANGE (1 << 7)
+
+/* R3 Response : OCR Register */
+#define OCR_HCS_CCS (0x1 << 30)
+#define OCR_LOW_VOLTAGE (0x01 << 24)
+#define OCR_3_3V (0x1 << 20)
+
+/* R7 response pattern for CMD8 */
+#define CMD8_PATTERN (0xAA)
+
+/* CRC Enable */
+#define CRC_ENABLE (0) /*!< CRC 1 - Enable 0 - Disable */
+
+/* Control Tokens */
+#define SPI_DATA_RESPONSE_MASK (0x1F)
+#define SPI_DATA_ACCEPTED (0x05)
+#define SPI_DATA_CRC_ERROR (0x0B)
+#define SPI_DATA_WRITE_ERROR (0x0D)
+#define SPI_START_BLOCK (0xFE) /*!< For Single Block Read/Write and Multiple Block Read */
+#define SPI_START_BLK_MUL_WRITE (0xFC) /*!< Start Multi-block write */
+#define SPI_STOP_TRAN (0xFD) /*!< Stop Multi-block write */
+
+#define SPI_DATA_READ_ERROR_MASK (0xF) /*!< Data Error Token: 4 LSB bits */
+#define SPI_READ_ERROR (0x1 << 0) /*!< Error */
+#define SPI_READ_ERROR_CC (0x1 << 1) /*!< CC Error*/
+#define SPI_READ_ERROR_ECC_C (0x1 << 2) /*!< Card ECC failed */
+#define SPI_READ_ERROR_OFR (0x1 << 3) /*!< Out of Range */
+
+SDBlockDevice::SDBlockDevice(PinName mosi, PinName miso, PinName sclk, PinName cs, uint64_t hz)
+ : _spi(mosi, miso, sclk), _cs(cs), _is_initialized(0)
+{
+ _cs = 1;
+ _card_type = SDCARD_NONE;
+
+ // Set default to 100kHz for initialisation and 1MHz for data transfer
+ _init_sck = 100000;
+ _transfer_sck = hz;
+
+ // Only HC block size is supported.
+ _block_size = BLOCK_SIZE_HC;
+}
+
+SDBlockDevice::~SDBlockDevice()
+{
+ if (_is_initialized) {
+ deinit();
+ }
+}
+
+int SDBlockDevice::_initialise_card()
+{
+ // Detail debugging is for commands
+ _dbg = SD_DBG ? SD_CMD_TRACE : 0;
+ int32_t status = BD_ERROR_OK;
+ uint32_t response, arg;
+
+ // Initialize the SPI interface: Card by default is in SD mode
+ _spi_init();
+
+ // The card is transitioned from SDCard mode to SPI mode by sending the CMD0 + CS Asserted("0")
+ if (_go_idle_state() != R1_IDLE_STATE) {
+ debug_if(SD_DBG, "No disk, or could not put SD card in to SPI idle state\n");
+ return SD_BLOCK_DEVICE_ERROR_NO_DEVICE;
+ }
+
+ // Send CMD8, if the card rejects the command then it's probably using the
+ // legacy protocol, or is a MMC, or just flat-out broken
+ status = _cmd8();
+ if (BD_ERROR_OK != status && SD_BLOCK_DEVICE_ERROR_UNSUPPORTED != status) {
+ return status;
+ }
+
+ // Read OCR - CMD58 Response contains OCR register
+ if (BD_ERROR_OK != (status = _cmd(CMD58_READ_OCR, 0x0, 0x0, &response))) {
+ return status;
+ }
+
+ // Check if card supports voltage range: 3.3V
+ if (!(response & OCR_3_3V)) {
+ _card_type = CARD_UNKNOWN;
+ status = SD_BLOCK_DEVICE_ERROR_UNUSABLE;
+ return status;
+ }
+
+ // HCS is set 1 for HC/XC capacity cards for ACMD41, if supported
+ arg = 0x0;
+ if (SDCARD_V2 == _card_type) {
+ arg |= OCR_HCS_CCS;
+ }
+
+ /* Idle state bit in the R1 response of ACMD41 is used by the card to inform the host
+ * if initialization of ACMD41 is completed. "1" indicates that the card is still initializing.
+ * "0" indicates completion of initialization. The host repeatedly issues ACMD41 until
+ * this bit is set to "0".
+ */
+ _spi_timer.start();
+ do {
+ status = _cmd(ACMD41_SD_SEND_OP_COND, arg, 1, &response);
+ } while ((response & R1_IDLE_STATE) && (_spi_timer.read_ms() < SD_COMMAND_TIMEOUT));
+ _spi_timer.stop();
+
+ // Initialization complete: ACMD41 successful
+ if ((BD_ERROR_OK != status) || (0x00 != response)) {
+ _card_type = CARD_UNKNOWN;
+ debug_if(SD_DBG, "Timeout waiting for card\n");
+ return status;
+ }
+
+ if (SDCARD_V2 == _card_type) {
+ // Get the card capacity CCS: CMD58
+ if (BD_ERROR_OK == (status = _cmd(CMD58_READ_OCR, 0x0, 0x0, &response))) {
+ // High Capacity card
+ if (response & OCR_HCS_CCS) {
+ _card_type = SDCARD_V2HC;
+ debug_if(SD_DBG, "Card Initialized: High Capacity Card \n");
+ } else {
+ debug_if(SD_DBG, "Card Initialized: Standard Capacity Card: Version 2.x \n");
+ }
+ }
+ } else {
+ _card_type = SDCARD_V1;
+ debug_if(SD_DBG, "Card Initialized: Version 1.x Card\n");
+ }
+
+ // Disable CRC
+ status = _cmd(CMD59_CRC_ON_OFF, 0);
+
+ return status;
+}
+
+
+int SDBlockDevice::init()
+{
+ _lock.lock();
+ int err = _initialise_card();
+ _is_initialized = (err == BD_ERROR_OK);
+ if (!_is_initialized) {
+ debug_if(SD_DBG, "Fail to initialize card\n");
+ _lock.unlock();
+ return err;
+ }
+ debug_if(SD_DBG, "init card = %d\n", _is_initialized);
+ _sectors = _sd_sectors();
+ // CMD9 failed
+ if (0 == _sectors) {
+ _lock.unlock();
+ return BD_ERROR_DEVICE_ERROR;
+ }
+
+ // Set block length to 512 (CMD16)
+ if (_cmd(CMD16_SET_BLOCKLEN, _block_size) != 0) {
+ debug_if(SD_DBG, "Set %d-byte block timed out\n", _block_size);
+ _lock.unlock();
+ return BD_ERROR_DEVICE_ERROR;
+ }
+
+ // Set SCK for data transfer
+ err = _freq();
+ if (err) {
+ _lock.unlock();
+ return err;
+ }
+ _lock.unlock();
+ return BD_ERROR_OK;
+}
+
+int SDBlockDevice::deinit()
+{
+ _lock.lock();
+ _is_initialized = false;
+ _lock.unlock();
+ return 0;
+}
+
+
+int SDBlockDevice::program(const void *b, bd_addr_t addr, bd_size_t size)
+{
+ if (!is_valid_program(addr, size)) {
+ return SD_BLOCK_DEVICE_ERROR_PARAMETER;
+ }
+
+ _lock.lock();
+ if (!_is_initialized) {
+ _lock.unlock();
+ return SD_BLOCK_DEVICE_ERROR_NO_INIT;
+ }
+
+ const uint8_t *buffer = static_cast<const uint8_t*>(b);
+ int status = BD_ERROR_OK;
+ uint8_t response;
+
+ // Get block count
+ bd_addr_t blockCnt = size / _block_size;
+
+ // SDSC Card (CCS=0) uses byte unit address
+ // SDHC and SDXC Cards (CCS=1) use block unit address (512 Bytes unit)
+ if(SDCARD_V2HC == _card_type) {
+ addr = addr / _block_size;
+ }
+
+ // Send command to perform write operation
+ if (blockCnt == 1) {
+ // Single block write command
+ if (BD_ERROR_OK != (status = _cmd(CMD24_WRITE_BLOCK, addr))) {
+ _lock.unlock();
+ return status;
+ }
+
+ // Write data
+ response = _write(buffer, SPI_START_BLOCK, _block_size);
+
+ // Only CRC and general write error are communicated via response token
+ if ((response == SPI_DATA_CRC_ERROR) || (response == SPI_DATA_WRITE_ERROR)) {
+ debug_if(SD_DBG, "Single Block Write failed: 0x%x \n", response);
+ status = SD_BLOCK_DEVICE_ERROR_WRITE;
+ }
+ } else {
+ // Pre-erase setting prior to multiple block write operation
+ _cmd(ACMD23_SET_WR_BLK_ERASE_COUNT, blockCnt, 1);
+
+ // Multiple block write command
+ if (BD_ERROR_OK != (status = _cmd(CMD25_WRITE_MULTIPLE_BLOCK, addr))) {
+ _lock.unlock();
+ return status;
+ }
+
+ // Write the data: one block at a time
+ do {
+ response = _write(buffer, SPI_START_BLK_MUL_WRITE, _block_size);
+ if (response != SPI_DATA_ACCEPTED) {
+ debug_if(SD_DBG, "Multiple Block Write failed: 0x%x \n", response);
+ break;
+ }
+ buffer += _block_size;
+ }while (--blockCnt); // Receive all blocks of data
+
+ /* In a Multiple Block write operation, the stop transmission will be done by
+ * sending 'Stop Tran' token instead of 'Start Block' token at the beginning
+ * of the next block
+ */
+ _spi.write(SPI_STOP_TRAN);
+ }
+
+ _deselect();
+ _lock.unlock();
+ return status;
+}
+
+int SDBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
+{
+ if (!is_valid_read(addr, size)) {
+ return SD_BLOCK_DEVICE_ERROR_PARAMETER;
+ }
+
+ _lock.lock();
+ if (!_is_initialized) {
+ _lock.unlock();
+ return SD_BLOCK_DEVICE_ERROR_PARAMETER;
+ }
+
+ uint8_t *buffer = static_cast<uint8_t *>(b);
+ int status = BD_ERROR_OK;
+ bd_addr_t blockCnt = size / _block_size;
+
+ // SDSC Card (CCS=0) uses byte unit address
+ // SDHC and SDXC Cards (CCS=1) use block unit address (512 Bytes unit)
+ if (SDCARD_V2HC == _card_type) {
+ addr = addr / _block_size;
+ }
+
+ // Write command ro receive data
+ if (blockCnt > 1) {
+ status = _cmd(CMD18_READ_MULTIPLE_BLOCK, addr);
+ } else {
+ status = _cmd(CMD17_READ_SINGLE_BLOCK, addr);
+ }
+ if (BD_ERROR_OK != status) {
+ _lock.unlock();
+ return status;
+ }
+
+ // receive the data : one block at a time
+ while (blockCnt) {
+ if (0 != _read(buffer, _block_size)) {
+ status = SD_BLOCK_DEVICE_ERROR_NO_RESPONSE;
+ break;
+ }
+ buffer += _block_size;
+ --blockCnt;
+ }
+ _deselect();
+
+ // Send CMD12(0x00000000) to stop the transmission for multi-block transfer
+ if (size > _block_size) {
+ status = _cmd(CMD12_STOP_TRANSMISSION, 0x0);
+ }
+ _lock.unlock();
+ return status;
+}
+
+bool SDBlockDevice::_is_valid_trim(bd_addr_t addr, bd_size_t size)
+{
+ return (
+ addr % _erase_size == 0 &&
+ size % _erase_size == 0 &&
+ addr + size <= this->size());
+}
+
+int SDBlockDevice::trim(bd_addr_t addr, bd_size_t size)
+{
+ if (!_is_valid_trim(addr, size)) {
+ return SD_BLOCK_DEVICE_ERROR_PARAMETER;
+ }
+
+ _lock.lock();
+ if (!_is_initialized) {
+ _lock.unlock();
+ return SD_BLOCK_DEVICE_ERROR_NO_INIT;
+ }
+ int status = BD_ERROR_OK;
+
+ size -= _block_size;
+ // SDSC Card (CCS=0) uses byte unit address
+ // SDHC and SDXC Cards (CCS=1) use block unit address (512 Bytes unit)
+ if (SDCARD_V2HC == _card_type) {
+ size = size / _block_size;
+ addr = addr / _block_size;
+ }
+
+ // Start lba sent in start command
+ if (BD_ERROR_OK != (status = _cmd(CMD32_ERASE_WR_BLK_START_ADDR, addr))) {
+ _lock.unlock();
+ return status;
+ }
+
+ // End lba = addr+size sent in end addr command
+ if (BD_ERROR_OK != (status = _cmd(CMD33_ERASE_WR_BLK_END_ADDR, addr+size))) {
+ _lock.unlock();
+ return status;
+ }
+ status = _cmd(CMD38_ERASE, 0x0);
+ _lock.unlock();
+ return status;
+}
+
+bd_size_t SDBlockDevice::get_read_size() const
+{
+ return _block_size;
+}
+
+bd_size_t SDBlockDevice::get_program_size() const
+{
+ return _block_size;
+}
+
+bd_size_t SDBlockDevice::size() const
+{
+ bd_size_t sectors = 0;
+ _lock.lock();
+ if (_is_initialized) {
+ sectors = _sectors;
+ }
+ _lock.unlock();
+ return _block_size*sectors;
+}
+
+void SDBlockDevice::debug(bool dbg)
+{
+ _dbg = dbg;
+}
+
+int SDBlockDevice::frequency(uint64_t freq)
+{
+ _lock.lock();
+ _transfer_sck = freq;
+ int err = _freq();
+ _lock.unlock();
+ return err;
+}
+
+// PRIVATE FUNCTIONS
+int SDBlockDevice::_freq(void)
+{
+ // Max frequency supported is 25MHZ
+ if (_transfer_sck <= 25000000) {
+ _spi.frequency(_transfer_sck);
+ return 0;
+ } else { // TODO: Switch function to be implemented for higher frequency
+ _transfer_sck = 25000000;
+ _spi.frequency(_transfer_sck);
+ return -EINVAL;
+ }
+}
+
+uint8_t SDBlockDevice::_cmd_spi(SDBlockDevice::cmdSupported cmd, uint32_t arg) {
+ uint8_t response;
+ char cmdPacket[PACKET_SIZE];
+
+ // Prepare the command packet
+ cmdPacket[0] = SPI_CMD(cmd);
+ cmdPacket[1] = (arg >> 24);
+ cmdPacket[2] = (arg >> 16);
+ cmdPacket[3] = (arg >> 8);
+ cmdPacket[4] = (arg >> 0);
+ // CMD0 is executed in SD mode, hence should have correct CRC
+ // CMD8 CRC verification is always enabled
+ switch(cmd) {
+ case CMD0_GO_IDLE_STATE:
+ cmdPacket[5] = 0x95;
+ break;
+ case CMD8_SEND_IF_COND:
+ cmdPacket[5] = 0x87;
+ break;
+ default:
+ cmdPacket[5] = 0xFF; // Make sure bit 0-End bit is high
+ break;
+ }
+
+ // send a command
+ for (int i = 0; i < PACKET_SIZE; i++) {
+ _spi.write(cmdPacket[i]);
+ }
+
+ // The received byte immediataly following CMD12 is a stuff byte,
+ // it should be discarded before receive the response of the CMD12.
+ if (CMD12_STOP_TRANSMISSION == cmd) {
+ _spi.write(SPI_FILL_CHAR);
+ }
+
+ // Loop for response: Response is sent back within command response time (NCR), 0 to 8 bytes for SDC
+ for (int i = 0; i < 0x10; i++) {
+ response = _spi.write(SPI_FILL_CHAR);
+ // Got the response
+ if (!(response & R1_RESPONSE_RECV)) {
+ break;
+ }
+ }
+ return response;
+}
+
+int SDBlockDevice::_cmd(SDBlockDevice::cmdSupported cmd, uint32_t arg, bool isAcmd, uint32_t *resp) {
+ int32_t status = BD_ERROR_OK;
+ uint32_t response;
+
+ // Select card and wait for card to be ready before sending next command
+ // Note: next command will fail if card is not ready
+ _select();
+
+ // No need to wait for card to be ready when sending the stop command
+ if (CMD12_STOP_TRANSMISSION != cmd) {
+ if (false == _wait_ready(SD_COMMAND_TIMEOUT)) {
+ debug_if(SD_DBG, "Card not ready yet \n");
+ }
+ }
+
+ // Re-try command
+ for(int i = 0; i < 3; i++) {
+ // Send CMD55 for APP command first
+ if (isAcmd) {
+ response = _cmd_spi(CMD55_APP_CMD, 0x0);
+ // Wait for card to be ready after CMD55
+ if (false == _wait_ready(SD_COMMAND_TIMEOUT)) {
+ debug_if(SD_DBG, "Card not ready yet \n");
+ }
+ }
+
+ // Send command over SPI interface
+ response = _cmd_spi(cmd, arg);
+ if (R1_NO_RESPONSE == response) {
+ debug_if(SD_DBG, "No response CMD:%d \n", cmd);
+ continue;
+ }
+ break;
+ }
+
+ // Pass the response to the command call if required
+ if (NULL != resp) {
+ *resp = response;
+ }
+
+ // Process the response R1 : Exit on CRC/Illegal command error/No response
+ if (R1_NO_RESPONSE == response) {
+ _deselect();
+ debug_if(SD_DBG, "No response CMD:%d response: 0x%x\n",cmd, response);
+ return SD_BLOCK_DEVICE_ERROR_NO_DEVICE; // No device
+ }
+ if (response & R1_COM_CRC_ERROR) {
+ _deselect();
+ debug_if(SD_DBG, "CRC error CMD:%d response 0x%x \n",cmd, response);
+ return SD_BLOCK_DEVICE_ERROR_CRC; // CRC error
+ }
+ if (response & R1_ILLEGAL_COMMAND) {
+ _deselect();
+ debug_if(SD_DBG, "Illegal command CMD:%d response 0x%x\n",cmd, response);
+ if (CMD8_SEND_IF_COND == cmd) { // Illegal command is for Ver1 or not SD Card
+ _card_type = CARD_UNKNOWN;
+ }
+ return SD_BLOCK_DEVICE_ERROR_UNSUPPORTED; // Command not supported
+ }
+
+ debug_if(_dbg, "CMD:%d \t arg:0x%x \t Response:0x%x \n", cmd, arg, response);
+ // Set status for other errors
+ if ((response & R1_ERASE_RESET) || (response & R1_ERASE_SEQUENCE_ERROR)) {
+ status = SD_BLOCK_DEVICE_ERROR_ERASE; // Erase error
+ }else if ((response & R1_ADDRESS_ERROR) || (response & R1_PARAMETER_ERROR)) {
+ // Misaligned address / invalid address block length
+ status = SD_BLOCK_DEVICE_ERROR_PARAMETER;
+ }
+
+ // Get rest of the response part for other commands
+ switch(cmd) {
+ case CMD8_SEND_IF_COND: // Response R7
+ debug_if(_dbg, "V2-Version Card\n");
+ _card_type = SDCARD_V2;
+ // Note: No break here, need to read rest of the response
+ case CMD58_READ_OCR: // Response R3
+ response = (_spi.write(SPI_FILL_CHAR) << 24);
+ response |= (_spi.write(SPI_FILL_CHAR) << 16);
+ response |= (_spi.write(SPI_FILL_CHAR) << 8);
+ response |= _spi.write(SPI_FILL_CHAR);
+ debug_if(_dbg, "R3/R7: 0x%x \n", response);
+ break;
+
+ case CMD12_STOP_TRANSMISSION: // Response R1b
+ case CMD38_ERASE:
+ _wait_ready(SD_COMMAND_TIMEOUT);
+ break;
+
+ case ACMD13_SD_STATUS: // Response R2
+ response = _spi.write(SPI_FILL_CHAR);
+ debug_if(_dbg, "R2: 0x%x \n", response);
+ break;
+
+ default: // Response R1
+ break;
+ }
+
+ // Pass the updated response to the command
+ if (NULL != resp) {
+ *resp = response;
+ }
+
+ // Do not deselect card if read is in progress.
+ if (((CMD9_SEND_CSD == cmd) || (ACMD22_SEND_NUM_WR_BLOCKS == cmd) ||
+ (CMD24_WRITE_BLOCK == cmd) || (CMD25_WRITE_MULTIPLE_BLOCK == cmd) ||
+ (CMD17_READ_SINGLE_BLOCK == cmd) || (CMD18_READ_MULTIPLE_BLOCK == cmd))
+ && (BD_ERROR_OK == status)) {
+ return BD_ERROR_OK;
+ }
+ // Deselect card
+ _deselect();
+ return status;
+}
+
+int SDBlockDevice::_cmd8() {
+ uint32_t arg = (CMD8_PATTERN << 0); // [7:0]check pattern
+ uint32_t response = 0;
+ int32_t status = BD_ERROR_OK;
+
+ arg |= (0x1 << 8); // 2.7-3.6V // [11:8]supply voltage(VHS)
+
+ status = _cmd(CMD8_SEND_IF_COND, arg, 0x0, &response);
+ // Verify voltage and pattern for V2 version of card
+ if ((BD_ERROR_OK == status) && (SDCARD_V2 == _card_type)) {
+ // If check pattern is not matched, CMD8 communication is not valid
+ if((response & 0xFFF) != arg)
+ {
+ debug_if(SD_DBG, "CMD8 Pattern mismatch 0x%x : 0x%x\n", arg, response);
+ _card_type = CARD_UNKNOWN;
+ status = SD_BLOCK_DEVICE_ERROR_UNUSABLE;
+ }
+ }
+ return status;
+}
+
+uint32_t SDBlockDevice::_go_idle_state() {
+ uint32_t response;
+
+ /* Reseting the MCU SPI master may not reset the on-board SDCard, in which
+ * case when MCU power-on occurs the SDCard will resume operations as
+ * though there was no reset. In this scenario the first CMD0 will
+ * not be interpreted as a command and get lost. For some cards retrying
+ * the command overcomes this situation. */
+ for (int i = 0; i < SD_CMD0_GO_IDLE_STATE_RETRIES; i++) {
+ _cmd(CMD0_GO_IDLE_STATE, 0x0, 0x0, &response);
+ if (R1_IDLE_STATE == response)
+ break;
+ wait_ms(1);
+ }
+ return response;
+}
+
+int SDBlockDevice::_read_bytes(uint8_t *buffer, uint32_t length) {
+ uint16_t crc;
+
+ // read until start byte (0xFE)
+ if (false == _wait_token(SPI_START_BLOCK)) {
+ debug_if(SD_DBG, "Read timeout\n");
+ _deselect();
+ return SD_BLOCK_DEVICE_ERROR_NO_RESPONSE;
+ }
+
+ // read data
+ for (uint32_t i = 0; i < length; i++) {
+ buffer[i] = _spi.write(SPI_FILL_CHAR);
+ }
+
+ // Read the CRC16 checksum for the data block
+ crc = (_spi.write(SPI_FILL_CHAR) << 8);
+ crc |= _spi.write(SPI_FILL_CHAR);
+
+ _deselect();
+ return 0;
+}
+
+int SDBlockDevice::_read(uint8_t *buffer, uint32_t length) {
+ uint16_t crc;
+
+ // read until start byte (0xFE)
+ if (false == _wait_token(SPI_START_BLOCK)) {
+ debug_if(SD_DBG, "Read timeout\n");
+ _deselect();
+ return SD_BLOCK_DEVICE_ERROR_NO_RESPONSE;
+ }
+
+ // read data
+ _spi.write(NULL, 0, (char*)buffer, length);
+
+ // Read the CRC16 checksum for the data block
+ crc = (_spi.write(SPI_FILL_CHAR) << 8);
+ crc |= _spi.write(SPI_FILL_CHAR);
+
+ return 0;
+}
+
+uint8_t SDBlockDevice::_write(const uint8_t *buffer, uint8_t token, uint32_t length) {
+ uint16_t crc = 0xFFFF;
+ uint8_t response = 0xFF;
+
+ // indicate start of block
+ _spi.write(token);
+
+ // write the data
+ _spi.write((char*)buffer, length, NULL, 0);
+
+ // write the checksum CRC16
+ _spi.write(crc >> 8);
+ _spi.write(crc);
+
+ // check the response token
+ response = _spi.write(SPI_FILL_CHAR);
+
+ // Wait for last block to be written
+ if (false == _wait_ready(SD_COMMAND_TIMEOUT)) {
+ debug_if(SD_DBG, "Card not ready yet \n");
+ }
+
+ return (response & SPI_DATA_RESPONSE_MASK);
+}
+
+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;
+}
+
+uint32_t SDBlockDevice::_sd_sectors() {
+ uint32_t c_size, c_size_mult, read_bl_len;
+ uint32_t block_len, mult, blocknr;
+ uint32_t hc_c_size;
+ bd_size_t blocks = 0, capacity = 0;
+
+ // CMD9, Response R2 (R1 byte + 16-byte block read)
+ if (_cmd(CMD9_SEND_CSD, 0x0) != 0x0) {
+ debug_if(SD_DBG, "Didn't get a response from the disk\n");
+ return 0;
+ }
+ uint8_t csd[16];
+ if (_read_bytes(csd, 16) != 0) {
+ debug_if(SD_DBG, "Couldn't read csd response from disk\n");
+ return 0;
+ }
+
+ // csd_structure : csd[127:126]
+ int csd_structure = ext_bits(csd, 127, 126);
+ switch (csd_structure) {
+ case 0:
+ c_size = ext_bits(csd, 73, 62); // c_size : csd[73:62]
+ c_size_mult = ext_bits(csd, 49, 47); // c_size_mult : csd[49:47]
+ read_bl_len = ext_bits(csd, 83, 80); // read_bl_len : csd[83:80] - the *maximum* read block length
+ block_len = 1 << read_bl_len; // BLOCK_LEN = 2^READ_BL_LEN
+ mult = 1 << (c_size_mult + 2); // MULT = 2^C_SIZE_MULT+2 (C_SIZE_MULT < 8)
+ blocknr = (c_size + 1) * mult; // BLOCKNR = (C_SIZE+1) * MULT
+ capacity = blocknr * block_len; // memory capacity = BLOCKNR * BLOCK_LEN
+ blocks = capacity / _block_size;
+ debug_if(SD_DBG, "Standard Capacity: c_size: %d \n", c_size);
+ debug_if(SD_DBG, "Sectors: 0x%x : %llu\n", blocks, blocks);
+ debug_if(SD_DBG, "Capacity: 0x%x : %llu MB\n", capacity, (capacity/(1024U*1024U)));
+
+ // ERASE_BLK_EN = 1: Erase in multiple of 512 bytes supported
+ if (ext_bits(csd, 46, 46)) {
+ _erase_size = BLOCK_SIZE_HC;
+ } else {
+ // ERASE_BLK_EN = 1: Erase in multiple of SECTOR_SIZE supported
+ _erase_size = BLOCK_SIZE_HC * (ext_bits(csd, 45, 39) + 1);
+ }
+ break;
+
+ case 1:
+ hc_c_size = ext_bits(csd, 69, 48); // device size : C_SIZE : [69:48]
+ blocks = (hc_c_size+1) << 10; // block count = C_SIZE+1) * 1K byte (512B is block size)
+ debug_if(SD_DBG, "SDHC/SDXC Card: hc_c_size: %d \n", hc_c_size);
+ debug_if(SD_DBG, "Sectors: 0x%x : %llu\n", blocks, blocks);
+ debug_if(SD_DBG, "Capacity: %llu MB\n", (blocks/(2048U)));
+ // ERASE_BLK_EN is fixed to 1, which means host can erase one or multiple of 512 bytes.
+ _erase_size = BLOCK_SIZE_HC;
+ break;
+
+ default:
+ debug_if(SD_DBG, "CSD struct unsupported\r\n");
+ return 0;
+ };
+ return blocks;
+}
+
+// SPI function to wait till chip is ready and sends start token
+bool SDBlockDevice::_wait_token(uint8_t token) {
+ _spi_timer.reset();
+ _spi_timer.start();
+
+ do {
+ if (token == _spi.write(SPI_FILL_CHAR)) {
+ _spi_timer.stop();
+ return true;
+ }
+ } while (_spi_timer.read_ms() < 300); // Wait for 300 msec for start token
+ _spi_timer.stop();
+ debug_if(SD_DBG, "_wait_token: timeout\n");
+ return false;
+}
+
+// SPI function to wait till chip is ready
+// The host controller should wait for end of the process until DO goes high (a 0xFF is received).
+bool SDBlockDevice::_wait_ready(uint16_t ms) {
+ uint8_t response;
+ _spi_timer.reset();
+ _spi_timer.start();
+ do {
+ response = _spi.write(SPI_FILL_CHAR);
+ if (response == 0xFF) {
+ _spi_timer.stop();
+ return true;
+ }
+ } while (_spi_timer.read_ms() < ms);
+ _spi_timer.stop();
+ return false;
+}
+
+// SPI function to wait for count
+void SDBlockDevice::_spi_wait(uint8_t count)
+{
+ for (uint8_t i = 0; i < count; ++i) {
+ _spi.write(SPI_FILL_CHAR);
+ }
+}
+
+void SDBlockDevice::_spi_init() {
+ _spi.lock();
+ // Set to SCK for initialization, and clock card with cs = 1
+ _spi.frequency(_init_sck);
+ _spi.format(8, 0);
+ _spi.set_default_write_value(SPI_FILL_CHAR);
+ // Initial 74 cycles required for few cards, before selecting SPI mode
+ _cs = 1;
+ _spi_wait(10);
+ _spi.unlock();
+}
+
+void SDBlockDevice::_select() {
+ _spi.lock();
+ _spi.write(SPI_FILL_CHAR);
+ _cs = 0;
+}
+
+void SDBlockDevice::_deselect() {
+ _cs = 1;
+ _spi.write(SPI_FILL_CHAR);
+ _spi.unlock();
+}
+
+#endif /* DEVICE_SPI */