Reset the device in init as it can be in a bad state. This is necessary
because a block write will wait for data to be placed in the output buffer
and block any later commands which will keep accumulating and the device
will not be idle. Another case is removing the ds2490 module while a bus
search is in progress, somehow a few commands get through, but the input
transfers fail leaving data in the input buffer. This will cause the next
read to fail see the note in ds_recv_data.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ds_reset no longer calls ds_wait_status, the result wasn't used and it
would only delay the following data operations.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- add result register #defines
- rename ds_dump_status to ds_print_msg
- rename ds_recv_status to ds_dump_status
- ds_dump_status prints the requested status and no longer reads the
status, this is because the second status read can return different
data for example the result register
- the result register will be printed, though limited to detecting a
new device, detecting other values such as a short would require
additional reporting methods
- ST_EPOF was moved to ds_wait_status to clear the error condition
sooner
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simplify and fix ds_touch_bit. If a device is attached in the middle of a
bus search the status register will return more than the default 16 bytes.
The additional bytes indicate that it has detected a new device. The way
ds_wait_status is coded, if it doesn't read 16 status bytes it returns an
error value. ds_touch_bit then will detect that error and return an
error. In that case it doesn't read the input buffer and returns
uninitialized data. It doesn't stop there. The next transaction will not
expect the extra byte in the input buffer and the short read will cause an
error and clear out both the old byte and new data in the input buffer.
Just ignore the value of ds_wait_status. It is still required to wait
until ds2490 is again idle and there is data to read when ds_recv_data is
called. This also removes the while loop. None of the other commands
wait and verify that the issued command is in the status register.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't export read and write bit operations, they didn't work, they weren't
used, and they can't be made to work. The one wire low level bit
operations expect to set high or low levels, the ds2490 hardware only
supports complete read or write time slots, better to just comment them
out.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ds_write_bit doesn't read the input buffer, so add COMM_ICP and a comment
that it will no longer generate a read back data byte. If there is an
extra data byte later on then it will cause an error and discard what data
was there. Corrected operator ordering for ds_send_control.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add strong pullup support for ds2490 driver, also drop mdelay(750), which
busy waits, usage in favour of msleep for long delays. Now with msleep
only being called when the strong pullup is active, one wire bus
operations are only taking minimal system overhead.
The new set_pullup will only enable the strong pullup when requested,
which is expected to be the only write operation that will benefit from a
strong pullup.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Corrected print message, it was writing not reading, this also prints the
endpoint used for the write instead of hardcoding it. Failed to write
1-wire data to ep0x%x: err=%d.
Signed-off-by: David Fries <david@fries.net>
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size argument passed to memset is wrong.
Signed-off-by Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use mutexes instead of semaphores.
Patch tested on x86_64 and i386 with test bus master driver.
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
