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 <[email protected]>
Acked-by: Haavard Skinnemoen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions