Now the same SPI controller driver is reusable in all Allwinner
SoC variants, so rename the existing sun4i_spi.c into spi-sunxi.c
which eventually look like a common sunxi driver.

Also update the function, variable, structure names in driver from
sun4i into sunxi.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

- drop unused macros.
- use base instead of base_addr, for better code readability
- move .probe and .ofdata_to_platdata functions in required
  places to add platdata support in future.
- use sentinel sun4i_spi_ids.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

The usual SPI transmission protocol in Allwinner A10 and A31
controllers share similar context with minimal changes in register
offsets along with few additional register bits on A31.

So, add A31 spi controller support in existing sun4i_spi with A31
specific register offsets and bits.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

Add CLK support to enable AHB and MOD SPI clocks on sun4i_spi driver.

Clock disablement could be done while releasing the bus transfer, but
the existing code doesn't disable the clocks it only taken care of clock
enablement globally in probe.

So to make a proper clock handling, the clocks should enable it in claim
and disable it in release.

This patch would also do that change, by enable and disable clock in
proper order.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Support fifo_depth via drvdata instead of macro definition, this would
eventually reduce another macro definition for new SPI controller fifo
depth support addition.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Allwinner support two different SPI controllers one for A10 and
another for A31 with minimal changes in register offsets and
respective register bits, but the logic for accessing the SPI
master via SPI slave remains nearly similar.

Add enum offsets for register set and register bits, so-that
it can access both classes of SPI controllers.

Assign same control register for global, transfer and fifo control
registers to make the same code compatible with A31 SPI controller.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Stefan Mavrodiev <stefan@olimex.com> # A20-SOM204

Update the existing register writes using setbits_le32 and
clrbits_le32 in required places.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

To drain rx fifo the fifo need to poll for how much data has
been filled up in rx fifo.

To achieve this, the current code is using wait_for_bit logic
on control register with exchange burst mode mask, which is not
a proper way of waiting for fifo filled up.

So, add code for polling rxfifo to be filled up using fifo
status register.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>

With current order of include files, the file designware_spi.c
can't see that the struct global_data has the member
board_type when CONFIG_BOARD_TYPES is defined. By not seeing this
then all the members are shifted in the struct global_data.
So when the driver is trying to read from device tree blob, it
would pass the wrong address to the function 'fdtdev_get_int'.
This will make to use the default frequency 500000.

The fix consists of changing the order of include files in
designware_spi.c to include first common.h file.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

_omap3_spi_set_wordlen() indexed the regs->channel[] array with the
old wordlen (instead of the chipselect number) when reading the current
CHCONF register value. This meant it read from the wrong memory location,
modified that value, and then wrote it back to the correct CHCONF
register. The end result is that most slave configuration settings would
be lost, such as clock divisor, clock/chipselect polarities, etc.

Fixes: 77b8d04854f4 ("spi: omap3: Convert to driver model")
Signed-off-by: David Rivshin <drivshin@allworx.com>