The commit df59fa7f4b "spi: orion: support armada extended baud
rates" made the assumptions that all the Armada SoCs supported the
same maximum frequency. However, according the hardware datasheet, the
maximum frequency supported by the Armada 370 SoC is tclk/4, for the
Armada XP, Armada 38x and Armada 39x SoCs the limitation is 50MHz and
for the Armada 375 it is tclk/15.
This patch introduces new compatible strings to handle all these
case. In order to be future proof a compatible was created for each
SoC even if currently some SoCs seem using the same IP.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The Armada SoC family implementation of this SPI hardware module has
extended the configuration register to allow for a wider range of SPI
clock rates. Specifically the Serial Baud Rate Pre-selection bits in the
SPI Interface Configuration Register now also use bits 6 and 7 as well.
Modify the baud rate calculation to handle these differences for the
Armada case. Potentially a baud rate can be setup using a number of
different pre-scalar and scalar combinations. This code tries all
possible pre-scalar divisors (8 in total) to try and find the most
accurate set.
This change introduces (and documents) a new device tree compatible
device name "armada-370-spi" to support this.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Reviewed-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@googlemail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Gregory CLEMENT