diff options
Diffstat (limited to 'drivers/sdcard/sdcard.py')
| -rw-r--r-- | drivers/sdcard/sdcard.py | 88 |
1 files changed, 68 insertions, 20 deletions
diff --git a/drivers/sdcard/sdcard.py b/drivers/sdcard/sdcard.py index a3372e3152..fba383ae39 100644 --- a/drivers/sdcard/sdcard.py +++ b/drivers/sdcard/sdcard.py @@ -25,6 +25,9 @@ class SDCard: #R1_ERASE_SEQUENCE_ERROR = const(1 << 4) #R1_ADDRESS_ERROR = const(1 << 5) #R1_PARAMETER_ERROR = const(1 << 6) + TOKEN_CMD25 = const(0xfc) + TOKEN_STOP_TRAN = const(0xfd) + TOKEN_DATA = const(0xfe) def __init__(self, spi, cs): self.spi = spi @@ -136,6 +139,18 @@ class SDCard: self.spi.send(0xff) return -1 + def cmd_nodata(self, cmd): + self.spi.send(cmd) + self.spi.send_recv(0xff) # ignore stuff byte + for _ in range(CMD_TIMEOUT): + if self.spi.send_recv(0xff)[0] == 0xff: + self.cs.high() + self.spi.send(0xff) + return 0 # OK + self.cs.high() + self.spi.send(0xff) + return 1 # timeout + def readinto(self, buf): self.cs.low() @@ -154,11 +169,11 @@ class SDCard: self.cs.high() self.spi.send(0xff) - def write(self, buf): + def write(self, token, buf): self.cs.low() # send: start of block, data, checksum - self.spi.send(0xfe) + self.spi.send(token) self.spi.send(buf) self.spi.send(0xff) self.spi.send(0xff) @@ -176,29 +191,62 @@ class SDCard: self.cs.high() self.spi.send(0xff) + def write_token(self, token): + self.cs.low() + self.spi.send(token) + self.spi.send(0xff) + # wait for write to finish + while self.spi.send_recv(0xff)[0] == 0: + pass + + self.cs.high() + self.spi.send(0xff) + def count(self): return self.sectors def readblocks(self, block_num, buf): - # TODO support multiple block reads - assert len(buf) == 512 - - # CMD17: set read address for single block - if self.cmd(17, block_num * self.cdv, 0) != 0: - return 1 - - # receive the data - self.readinto(buf) + nblocks, err = divmod(len(buf), 512) + assert nblocks and not err, 'Buffer length is invalid' + if nblocks == 1: + # CMD17: set read address for single block + if self.cmd(17, block_num * self.cdv, 0) != 0: + return 1 + # receive the data + self.readinto(buf) + else: + # CMD18: set read address for multiple blocks + if self.cmd(18, block_num * self.cdv, 0) != 0: + return 1 + offset = 0 + mv = memoryview(buf) + while nblocks: + self.readinto(mv[offset : offset + 512]) + offset += 512 + nblocks -= 1 + return self.cmd_nodata(12) return 0 def writeblocks(self, block_num, buf): - # TODO support multiple block writes - assert len(buf) == 512 - - # CMD24: set write address for single block - if self.cmd(24, block_num * self.cdv, 0) != 0: - return 1 - - # send the data - self.write(buf) + nblocks, err = divmod(len(buf), 512) + assert nblocks and not err, 'Buffer length is invalid' + if nblocks == 1: + # CMD24: set write address for single block + if self.cmd(24, block_num * self.cdv, 0) != 0: + return 1 + + # send the data + self.write(TOKEN_DATA, buf) + else: + # CMD25: set write address for first block + if self.cmd(25, block_num * self.cdv, 0) != 0: + return 1 + # send the data + offset = 0 + mv = memoryview(buf) + while nblocks: + self.write(TOKEN_CMD25, mv[offset : offset + 512]) + offset += 512 + nblocks -= 1 + self.write_token(TOKEN_STOP_TRAN) return 0 |