Use bcm2835-mmc driver on ARCH_BCM2835

Use downstream bcm2835-mmc driver to get increased throughput
and DMA support.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Enable the downstream bcm2835-mmc driver and DMA support.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Make the bcm2835-mmc driver available for use on ARCH_BCM2835.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Some options in bcm2835_defconfig are now the default and
some have changed. Update to keep functionality.

No longer available: SCSI_MULTI_LUN and RESOURCE_COUNTERS.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Make legacy DMA API available on ARCH_BCM2835

BCM2835 has two SD card interfaces. This driver uses the other one.

This reverts commit c8ffccda.

This reverts commit d441bcba.

Remove the dmaman device since the dmaengine now handles
the legacy API manager.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Remove dma.c driver which is now merged with bcm2708-dmaengine.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Merge the legacy DMA API driver with bcm2708-dmaengine.
This is done so we can use bcm2708_fb on ARCH_BCM2835 (mailbox
driver is also needed).

Changes to the dma.c code:
- Use BIT() macro.
- Cutdown some comments to one line.
- Add mutex to vc_dmaman and use this, since the dev lock is locked
  during probing of the engine part.
- Add global g_dmaman variable since drvdata is used by the engine part.
- Restructure for readability:
  vc_dmaman_chan_alloc()
  vc_dmaman_chan_free()
  bcm_dma_chan_free()
- Restructure bcm_dma_chan_alloc() to simplify error handling.
- Use device irq resources instead of hardcoded bcm_dma_irqs table.
- Remove dev_dmaman_register() and code it directly.
- Remove dev_dmaman_deregister() and code it directly.
- Simplify bcm_dmaman_probe() using devm_* functions.
- Get dmachans from DT if available.
- Keep 'dma.dmachans' module argument name for backwards compatibility.

Make it available on ARCH_BCM2835 as well.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

Prepare for merging of the legacy DMA API arch driver dma.c
with bcm2708-dmaengine by adding memory and irq resources both
to platform file device and Device Tree node.
Don't use BCM_DMAMAN_DRIVER_NAME so we don't have to include mach/dma.h

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

BCM2835 has two SD card interfaces. This driver uses the other one.

The obsolete WIRELESS_EXT configuration is used
by the old Realtek code and is needed for AP support.

vcsm: Use boolean as it cannot be built as module

On building the bcm_vc_sm as a module we get the following error:

v7_dma_flush_range and do_munmap are undefined in vc-sm.ko.

Fix by making it not an option to build as module

The HiFiBerry Digi driver did not signal the sample rate in the SPDIF status bits.
While this is optional, some DACs and receivers do not accept this signal. This patch
adds the sample rate bits in the SPDIF status block.

smsc95xx is adjusting truesize when it shouldn't, and following a recent patch from Eric this is now triggering warnings.

This patch stops smsc95xx from changing truesize.

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>

The way that the timeout code is written in the polling function
the timeout does also trigger when interrupted or rescheduled while
in the polling loop.

This patch changes the timeout from effectively 20ms (=2 jiffies) to
1 second and removes the time that the transfer really takes out of
the computation, as - per design - this is <30us and the jiffie resolution
is 10ms so that does not make any difference what so ever.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>

In cases of short transfer times the CPU is spending lots of time
in the interrupt handler and scheduler to reschedule the worker thread.

Measurements show that we have times where it takes 29.32us to between
the last clock change and the time that the worker-thread is running again
returning from wait_for_completion_timeout().

During this time the interrupt-handler is running calling complete()
and then also the scheduler is rescheduling the worker thread.

This time can vary depending on how much of the code is still in
CPU-caches, when there is a burst of spi transfers the subsequent delays
are in the order of 25us, so the value of 30us seems reasonable.

With polling the whole transfer of 4 bytes at 10MHz finishes after 6.16us
(CS down to up) with the real transfer (clock running) taking 3.56us.
So the efficiency has much improved and is also freeing CPU cycles,
reducing interrupts and context switches.

Because of the above 30us seems to be a reasonable limit for polling.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Transforms the bcm-2835 native SPI-chip select to their gpio-cs equivalent.

This allows for some support of some optimizations that are not
possible due to HW-gliches on the CS line - especially filling
the FIFO before enabling SPI interrupts (by writing to CS register)
while the transfer is already in progress (See commit: e3a2be30

)

This patch also works arround some issues in bcm2835-pinctrl which does not
set the value when setting the GPIO as output - it just sets up output and
(typically) leaves the GPIO as low.  When a fix for this is merged then this
gpio_set_value can get removed from bcm2835_spi_setup.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

To reduce the number of interrupts/message we fill the FIFO before
enabling interrupts - for short messages this reduces the interrupt count
from 2 to 1 interrupt.

There have been rare cases where short (<200ns) chip-select switches with
native CS have been observed during such operation, this is why this
optimization is only enabled for GPIO-CS.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Tested-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Tested-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>