Skip to content

sdcard: Keep card selected across multi-block transfers. #1166

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
VinceParsons wants to merge 1 commit into
base: master
Choose a base branch
from
Open

sdcard: Keep card selected across multi-block transfers. #1166

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion micropython/drivers/storage/sdcard/manifest.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,3 +1,3 @@
metadata(description="SDCard block device driver.", version="0.2.0")
metadata(description="SDCard block device driver.", version="0.2.1")

module("sdcard.py", opt=3)
28 changes: 17 additions & 11 deletions micropython/drivers/storage/sdcard/sdcard.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -191,7 +191,7 @@ def cmd(self, cmd, arg, final=0, release=True, skip1=False):
self.spi.write(b"\xff")
return -1

def readinto(self, buf):
def readinto(self, buf, release=True):
self.cs(0)

# read until start byte (0xff)
Expand All @@ -214,10 +214,11 @@ def readinto(self, buf):
self.spi.write(b"\xff")
self.spi.write(b"\xff")

self.cs(1)
self.spi.write(b"\xff")
if release:
self.cs(1)
self.spi.write(b"\xff")

def write(self, token, buf):
def write(self, token, buf, release=True):
self.cs(0)

# send: start of block, data, checksum
Expand All @@ -236,8 +237,9 @@ def write(self, token, buf):
while self.spi.read(1, 0xFF)[0] == 0:
pass

self.cs(1)
self.spi.write(b"\xff")
if release:
self.cs(1)
self.spi.write(b"\xff")

def write_token(self, token):
self.cs(0)
Expand Down Expand Up @@ -274,8 +276,10 @@ def readblocks(self, block_num, buf):
offset = 0
mv = memoryview(buf)
while nblocks:
# receive the data and release card
self.readinto(mv[offset : offset + 512])
# receive the data, keeping the card selected until CMD12:
# some cards lose bit alignment if CS is released between
# the blocks of a multi-block read
self.readinto(mv[offset : offset + 512], release=False)
offset += 512
nblocks -= 1
if self.cmd(12, 0, skip1=True):
Expand All @@ -297,13 +301,15 @@ def writeblocks(self, block_num, buf):
self.write(_TOKEN_DATA, buf)
else:
# CMD25: set write address for first block
if self.cmd(25, block_num * self.cdv) != 0:
if self.cmd(25, block_num * self.cdv, release=False) != 0:
# release the card
self.cs(1)
raise OSError(5) # EIO
# send the data
# send the data, keeping the card selected until the stop token
offset = 0
mv = memoryview(buf)
while nblocks:
self.write(_TOKEN_CMD25, mv[offset : offset + 512])
self.write(_TOKEN_CMD25, mv[offset : offset + 512], release=False)
offset += 512
nblocks -= 1
self.write_token(_TOKEN_STOP_TRAN)
Expand Down
Loading