This one enables the mpc52xx_spi driver for usage of user defined gpio lines
as chipselect. This way we can control some more spi devices than only one
V2 Changes:
* preinitialize the gpio as output in probe function and call gpio_set_value in
the chip select function instead of calling direction_output every time.
* initialize the gpio line with output high, since we don't support CS_HIGH
in the driver currently any way. change gpio value setting to default active
low in chip select call.
* free the gpio array while error or removing.
Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Before reading status register to check MODF failure, we have to clear it
first since the MODF flag will be set after initializing the spi master,
if the hardware comes up with a low SS. The processor datasheet reads:
Mode Fault flag -- bit sets if SS input goes low while SPI is configured as a
master. Flag is cleared automatically by an SPI status register read (with MODF
set) followed by a SPI control register 1 write.
Hence simply rereading the register is not sufficient to clear the flag. We
redo the write also to make sure to clear the flag.
V2 Changes:
* change variable type from int to u8
Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Wolfram Sang
Luotao Fu
Grant Likely