atmel_spi: don't always deselect chip between messages
Update chipselect handling for atmel_spi:
* Teach it how to leave chipselect active between messages; this
helps various drivers work better.
* Cope with at91rm0200 errata: nCS0 can't be managed with GPIOs.
The MR.PCS value is now updated whenever a chipselect changes.
(This requires SPI pinmux init for that controller to change,
and also testing on rm9200; doesn't break at91sam9 or avr32.)
* Fix minor glitches: spi_setup() must leave chipselects inactive,
as must removal of the spi_device.
Also tweak diagnostic messaging to be a bit more useful.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 file changed