We are currently using an inferior or equal operator for comparing
the transfer frequency with the clock frequency table. Because of
this, we always end up selecting 20Mhz as a frequency, due to the
inequality transfer hz <= 20 Mhz being always true. Fix this by
reversing the inequality, which is how the comparison should be done.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We were not properly advertising the MODE bits supported by this driver, fix
that.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

We do not need to use a flag to indicate if the master driver is stopping
it is sufficient to perform spi master unregistering in the platform
driver's remove function.
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This patch converts the bcm63xx SPI driver to use the SPI infrastructure
pump message queue. Since we were previously sleeping in the SPI
driver's transfer() function (which is not allowed) this is now fixed as well.

To complete that conversion a certain number of changes have been made:
- the transfer len is split into multiple hardware transfers in case its
  size is bigger than the hardware FIFO size
- the FIFO refill is no longer done in the interrupt context, which was a
  bad idea leading to quick interrupt handler re-entrancy
Tested-by: NTanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

This patch adds support for the SPI controller found on the Broadcom BCM63xx
SoCs.
Signed-off-by: NTanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>