uint8_t MCP_rx_status(){
toggle_cs(0);
SPI_send(MCP_RX_STATUS); // send read rx status code: 0b10110000
uint8_t data = SPI_receive();
toggle_cs(1);
return data;
}
void MCP_write(uint8_t address, uint8_t data){
toggle_cs(0);
SPI_send(MCP_WRITE); //Send write command 0b00000010
SPI_send(address);
SPI_send(data);
toggle_cs(1);
}
void MCP_bit_modify(uint8_t address, uint8_t mask, uint8_t data){
toggle_cs(0);
SPI_send(MCP_BITMOD); // send bit modify command: 0b00000101
SPI_send(address);
SPI_send(mask);
SPI_send(data);
toggle_cs(1);
}
uint8_t MCP_read(uint8_t address){
toggle_cs(0);
SPI_send(MCP_READ); //Send read command 0b00000011
SPI_send(address);
uint8_t data = SPI_receive();
toggle_cs(1);
return data;
}
static int spi_flash_read_status(FlashOps *me)
{
int ret = -1;
SpiFlash *flash = container_of(me, SpiFlash, ops);
uint8_t command;
if (flash->spi->start(flash->spi)) {
printf("%s: Failed to start transaction.\n", __func__);
return ret;
}
if (toggle_cs(flash, "RDSTATUS") != 0)
goto fail;
command = ReadSr1Command;
if (flash->spi->transfer(flash->spi, NULL, &command, sizeof(command))) {
printf("%s: Failed to send register read command.\n", __func__);
goto fail;
}
if (flash->spi->transfer(flash->spi, &command, NULL, sizeof(command))) {
printf("%s: Failed to read status.\n", __func__);
goto fail;
}
ret = command;
fail:
if (flash->spi->stop(flash->spi)) {
printf("%s: Failed to stop.\n", __func__);
ret = -1;
}
return ret;
}
void MCP_rts(uint8_t buffer){
toggle_cs(0);
switch(buffer%4){ //Select buffer to use, 3 = all
case 0:
SPI_send(MCP_RTS_TX0);
break;
case 1:
SPI_send(MCP_RTS_TX1);
break;
case 2:
SPI_send(MCP_RTS_TX2);
break;
case 3:
SPI_send(MCP_RTS_ALL);
break;
default:
break;
}
toggle_cs(1);
}
static int spi_flash_write_status(FlashOps *me, uint8_t status)
{
int ret = -1;
SpiFlash *flash = container_of(me, SpiFlash, ops);
uint8_t command_bytes[2];
if (flash->spi->start(flash->spi)) {
printf("%s: Failed to start transaction.\n", __func__);
return ret;
}
command_bytes[0] = WriteEnableCommand;
if (flash->spi->transfer(flash->spi, NULL, &command_bytes, 1)) {
printf("%s: Failed to send write enable command.\n",
__func__);
goto fail;
}
if (operation_failed(flash, "WREN") != 0)
goto fail;
/*
* CS needs to be deasserted before any other command can be
* issued after WREN.
*/
if (toggle_cs(flash, "WREN"))
goto fail;
command_bytes[0] = WriteStatus;
command_bytes[1] = status;
if (flash->spi->transfer(flash->spi, NULL, &command_bytes, 2)) {
printf("%s: Failed to send write status command.\n", __func__);
goto fail;
}
if (operation_failed(flash, "WRSTATUS") == 0)
ret = 0;
fail:
if (flash->spi->stop(flash->spi)) {
printf("%s: Failed to stop.\n", __func__);
ret = -1;
}
return ret;
}
/*
* Poll device status register until write/erase operation has completed or
* timed out. Returns zero on success.
*/
static int operation_failed(SpiFlash *flash, const char *opname)
{
uint8_t value;
int i = 0;
if (toggle_cs(flash, opname))
return -1;
value = ReadSr1Command;
if (flash->spi->transfer(flash->spi, NULL, &value, sizeof(value))) {
printf("%s: Failed to send register read command.\n",
__func__);
return -1;
}
while (i++ < MAX_POLL_CYCLES) {
if (flash->spi->transfer(flash->spi, &value,
NULL, sizeof(value))) {
printf("%s: Failed to read status after %d cycles.\n",
__func__, i);
return -1;
}
if (!(value & SPI_FLASH_STATUS_WIP)) {
if (check_error(flash, value)) {
printf("%s: status %#x after %d cycles.\n",
__func__, value, i);
return -1;
}
return 0;
}
udelay(POLL_INTERVAL_US);
}
printf("%s: timeout waiting for %s completion\n", __func__, opname);
return -1;
}
/*
* Write or erase the flash. To write, pass a buffer and size; to erase,
* pass null for the buffer.
* This function is guaranteed to be invoked with data not spanning across
* writeable/erasable boundaries (page size/block size).
*/
static int spi_flash_modify(SpiFlash *flash, const void *buffer,
uint32_t offset, uint32_t size, uint8_t opcode,
const char *opname)
{
union {
uint8_t bytes[4]; // We're using 3 byte addresses.
uint32_t whole;
} command;
int stop_needed = 0;
uint32_t rv = -1;
do {
/* Each write or erase command requires a 'write enable' (WREN)
* first. */
if (flash->spi->start(flash->spi)) {
printf("%s: Failed to start WREN transaction.\n",
__func__);
break;
}
command.bytes[0] = WriteEnableCommand;
if (flash->spi->transfer(flash->spi, NULL, &command, 1)) {
printf("%s: Failed to send write enable command.\n",
__func__);
stop_needed = 1;
break;
}
/*
* CS needs to be deasserted before any other command can be
* issued after WREN.
*/
if (toggle_cs(flash, "WREN"))
break;
stop_needed = 1;
command.whole = swap_bytes32((opcode << 24) | offset);
if (flash->spi->transfer(flash->spi, NULL, &command, 4)) {
printf("%s: Failed to send %s command.\n",
__func__, opname);
break;
}
if (buffer &&
flash->spi->transfer(flash->spi, NULL, buffer, size)) {
printf("%s: Failed to write data.\n", __func__);
break;
}
stop_needed = 1;
if (!operation_failed(flash, opname))
rv = size;
} while(0);
if (stop_needed && flash->spi->stop(flash->spi))
printf("%s: Failed to stop.\n", __func__);
return rv;
}
void MCP_reset(){
toggle_cs(0); //CS low
SPI_transmit(MCP_RESET); // sen reset command 0b11000000
toggle_cs(1); //CS high
}
