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Single command function call for all commands supported
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5. Separated SPI functionality in different function call.
6. Used enums for existing commands using _cmd function.
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Deepika committed Jun 21, 2017
1 parent fbd1faf commit 27ceeee
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Showing 2 changed files with 78 additions and 28 deletions.
93 changes: 70 additions & 23 deletions features/filesystem/sd/SDBlockDevice.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -151,7 +151,7 @@
#define SD_CMD0_GO_IDLE_STATE_RETRIES 3 /*!< Number of retries for sending CMDO*/
#define SD_CMD0_GO_IDLE_STATE 0x00 /*!< CMD0 code value */
#define SD_CMD0_INVALID_RESPONSE_TIMEOUT -1 /*!< CMD0 received invalid responses and timed out */
#define SD_DBG 0
#define SD_DBG 1

#define SD_BLOCK_DEVICE_ERROR_WOULD_BLOCK -5001 /*!< operation would block */
#define SD_BLOCK_DEVICE_ERROR_UNSUPPORTED -5002 /*!< unsupported operation */
Expand All @@ -166,6 +166,7 @@

#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))


Expand Down Expand Up @@ -273,9 +274,11 @@ int SDBlockDevice::_initialise_card()

int SDBlockDevice::_initialise_card_v1()
{
uint32_t response;
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
_cmd(55, 0);
if (_cmd(41, 0) == 0) {
_cmd(CMD55_APP_CMD, 0);
_cmd(ACMD41_SD_SEND_OP_COND, 0, &response);
if (response == 0) {
_block_size = 512;
debug_if(_dbg, "\n\rInit: SEDCARD_V1\n\r");
return BD_ERROR_OK;
Expand All @@ -288,11 +291,13 @@ int SDBlockDevice::_initialise_card_v1()

int SDBlockDevice::_initialise_card_v2()
{
uint32_t response;
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
wait_ms(50);
_cmd58();
_cmd(55, 0);
if (_cmd(41, 0x40000000) == 0) {
_cmd(CMD55_APP_CMD, 0);
_cmd(ACMD41_SD_SEND_OP_COND, 0x40000000, &response);
if (response == 0) {
_cmd58();
debug_if(_dbg, "\n\rInit: SDCARD_V2\n\r");
_block_size = 1;
Expand All @@ -318,7 +323,7 @@ int SDBlockDevice::init()
_sectors = _sd_sectors();

// Set block length to 512 (CMD16)
if (_cmd(16, 512) != 0) {
if (_cmd(CMD16_SET_BLOCKLEN, 512) != 0) {
debug_if(_dbg, "Set 512-byte block timed out\n");
_lock.unlock();
return BD_ERROR_DEVICE_ERROR;
Expand Down Expand Up @@ -351,7 +356,7 @@ int SDBlockDevice::program(const void *b, bd_addr_t addr, bd_size_t size)
while (size > 0) {
bd_addr_t block = addr / 512;
// set write address for single block (CMD24)
if (_cmd(24, block * _block_size) != 0) {
if (_cmd(CMD24_WRITE_BLOCK, block * _block_size) != 0) {
_lock.unlock();
return BD_ERROR_DEVICE_ERROR;
}
Expand Down Expand Up @@ -382,7 +387,7 @@ int SDBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
while (size > 0) {
bd_addr_t block = addr / 512;
// set read address for single block (CMD17)
if (_cmd(17, block * _block_size) != 0) {
if (_cmd(CMD17_READ_SINGLE_BLOCK, block * _block_size) != 0) {
_lock.unlock();
return BD_ERROR_DEVICE_ERROR;
}
Expand Down Expand Up @@ -434,27 +439,69 @@ void SDBlockDevice::debug(bool dbg)
}

// PRIVATE FUNCTIONS
int SDBlockDevice::_cmd(int cmd, int arg) {
_select();
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
_spi.write(0x40 | cmd);
_spi.write(arg >> 24);
_spi.write(arg >> 16);
_spi.write(arg >> 8);
_spi.write(arg >> 0);
_spi.write(0x95);

for (int i = 0; i < PACKET_SIZE; i++) {
_spi.write(cmdPacket[i]);
}
// wait for the response (response[7] == 0)
for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
int response = _spi.write(0xFF);
if (!(response & 0x80)) {
_deselect();
return response;
response = _spi.write(0xFF);
// Got the response
if (!(response & R1_RESPONSE_RECV)) {
break;
}
}
return response;
}

int SDBlockDevice::_cmd(SDBlockDevice::cmdSupported cmd, uint32_t arg, uint32_t *resp) {
int32_t status = BD_ERROR_OK;
uint8_t response;
// Select card
_select();

// Send command over SPI interface
response = _cmd_spi(cmd, arg);
// Pass the response to the command call if required
if(NULL != resp) {
*resp = response;
}

// Process the response R1
if(R1_NO_RESPONSE == response) {
status = SD_BLOCK_DEVICE_ERROR_NO_DEVICE; // No device
}else if(response & R1_COM_CRC_ERROR) {
debug_if(SD_DBG, "CRC Error: CMD: %d\n", cmd);
status = SD_BLOCK_DEVICE_ERROR_CRC; // Retry for CRC
}

// Deselect card
_deselect();
return -1; // timeout
return status;
}

int SDBlockDevice::_cmd58() {
Expand Down Expand Up @@ -611,7 +658,7 @@ uint32_t SDBlockDevice::_sd_sectors() {
uint32_t blocks;

// CMD9, Response R2 (R1 byte + 16-byte block read)
if (_cmd(9, 0) != 0) {
if (_cmd(CMD9_SEND_CSD, 0) != 0) {
debug_if(_dbg, "Didn't get a response from the disk\n");
return 0;
}
Expand Down
13 changes: 8 additions & 5 deletions features/filesystem/sd/SDBlockDevice.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -168,7 +168,7 @@ class SDBlockDevice : public BlockDevice {
ACMD51_SEND_SCR = 51,
};

int _cmd(int cmd, int arg);
int _cmd(SDBlockDevice::cmdSupported cmd, uint32_t arg, uint32_t *resp=NULL);
int _cmd8();
int _cmd58();

Expand All @@ -193,16 +193,19 @@ class SDBlockDevice : public BlockDevice {
uint32_t _sd_sectors();
uint32_t _sectors;

uint32_t _init_sck;
uint32_t _transfer_sck;
/* SPI functions */
uint32_t _init_sck; /**< Intial SPI frequency */
uint32_t _transfer_sck; /**< SPI frequency during data transfer/after initialization */
SPI _spi;
void _spi_init();
uint8_t _cmd_spi(SDBlockDevice::cmdSupported cmd, uint32_t arg);

/* Chip Select and SPI mode select */
DigitalOut _cs;
void _select();
void _deselect();

DigitalOut _cs;
mutable Mutex _lock;

unsigned _block_size;
bool _is_initialized;
bool _dbg;
Expand Down

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