Commit Graph

6 Commits

Author SHA1 Message Date
Frank Schaefer
45f04e82d0 [media] em28xx: fix+improve+unify i2c error handling, debug messages and code comments
- do not pass USB specific error codes to userspace/i2c-subsystem
- unify the returned error codes and make them compliant with
  the i2c subsystem spec
- check number of actually transferred bytes (via USB) everywehere
- fix/improve debug messages
- improve code comments

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-01-05 01:18:25 -02:00
Frank Schaefer
eaf33c404c [media] em28xx: fix the i2c adapter functionality flags
I2C_FUNC_SMBUS_EMUL includes flag I2C_FUNC_SMBUS_WRITE_BLOCK_DATA which signals
that up to 31 data bytes can be written to the ic2 client.
But the EM2800 supports only i2c messages with max. 4 data bytes.
I2C_FUNC_IC2 should be set if a master_xfer function pointer is provided in
struct i2c_algorithm.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-01-05 01:16:54 -02:00
Frank Schaefer
2fcc82d883 [media] em28xx: fix two severe bugs in function em2800_i2c_recv_bytes()
Function em2800_i2c_recv_bytes() has 2 severe bugs:
1) It does not wait for the i2c read to complete before reading the received message content from the bridge registers.
2) Reading more than 1 byte doesn't work
The former can result in data corruption, the latter always does.
The rewritten code also superseds the content of function
em2800_i2c_check_for_device().
Tested with device "Terratec Cinergy 200 USB".

[mchehab@redhat.com: Fix CodingStyle issues]
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-01-05 01:16:01 -02:00
Frank Schaefer
f5ae371aca [media] em28xx: respect the message size constraints for i2c transfers
The em2800 can transfer up to 4 bytes per i2c message.
All other em25xx/em27xx/28xx chips can transfer at least 64 bytes per message.
I2C adapters should never split messages transferred via the I2C subsystem
into multiple message transfers, because the result will almost always NOT be
the same as when the whole data is transferred to the I2C client in a single
message.
If the message size exceeds the capabilities of the I2C adapter, -EOPNOTSUPP
should be returned.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2013-01-05 01:13:29 -02:00
Frank Schaefer
a6bad040da [media] em28xx: clean up the data type mess of the i2c transfer function parameters
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-12-22 21:48:29 -02:00
Mauro Carvalho Chehab
0c0d06cac6 [media] rename most media/video usb drivers to media/usb
Rename all USB drivers with their own directory under
drivers/media/video into drivers/media/usb and update the
building system.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-08-15 16:25:07 -03:00