ARM: at91: introduce OLD_IRQ_AT91 Kconfig option

Introduce the OLD_IRQ_AT91 Kconfig option to prepare migration to the
new AIC driver.

Select this option for all at91 SoCs and all available boards so that we
can later move DT enabled boards to the new irq driver and keep the old
implementation when legacy boards are selected.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: enclose at91_aic_xx calls in IS_ENABLED(CONFIG_OLD_IRQ_AT91) blocks

Enclose at91_aic_xx calls in IS_ENABLED(CONFIG_OLD_IRQ_AT91) blocks in
order to prepare migration to the new AIC driver.

In the new AIC driver the suspend/resume functions are called by the
generic irq framework and are no longer needed in the PM specific code.

Moreover, the new AIC driver no longer exposes the at91_aic_base variable
which is used by the at91_aic_read functions.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: make use of the new AIC driver for dt enabled boards

Remove selection of OLD_IRQ_AT91 when selecting dt boards.
Select ATMEL_AIC_IRQ for sama5 SoCs (a kernel compiled for this SoC will
always use ATMEL_AIC_IRQ driver).
Select ATMEL_AIC_IRQ for at91rm9200 and at91sam9 SoCs only if OLD_IRQ_AT91
is not selected (which means we are compiling a pure DT kernel, without
any legacy board support).

Remove specific irq init code in all dt board files: this init procedure
is automatically handled in of_irq_init which is called by the arm irq core
code and is in charge of calling the appropriate aic init functions.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: remove old irq material

Remove all the material related to AIC5 support: this interrupt controller
driver is now implemented in drivers/irqchip/atmel-aic.c.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Merge branches 'at91-3.18-cleanup' and 'at91-3.18-dt' into at91-3.18-drivers
Merge tag 'at91-drivers-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux

Pull AT91 reset, poweroff and ram drivers from Maxime Ripard:
 "This tag holds the various new drivers introduced to move code that used to be
  in mach-at91 over to the proper frameworks.

  These files are the reboot and poweroff code for all AT91 SoCs but the RM9200,
  and the ram controller driver is not doing much at the time, except for grabing
  the RAM clock in order to leave it always enabled."

Conflicts:
	arch/arm/mach-at91/Kconfig
ARM: at91: setup: Switch to pr_fmt

Most of the printed messages are using the "AT91:" prefix in the setup.c file,
but not all of them. Moreover, those who add it hardcode it directly in the
message, while the pr_fmt macro makes it easier for us to support such a case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Rework ramc mapping code

Adapt the ramc mapping code to handle multiple ram controllers in the DT.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove the old-style reset probing

Now that the reset code is a driver of its own, just let the usual DT probing
mecanism do its job, and remove the code entirely in this case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/soc: Introduce register_devices callback

Some core devices should be registered by the SoC itself rather than by every
board using this SoC. Introduce a register_devices callback that should be
called during the init_machine in order to do that.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Probe the reset driver

Register the reset device in the right SoCs so that the reset driver is
actually probed even in the old-style probing case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Call at91_register_devices in the board files

Make every board call the register_devices callback so that the devices
declared by the SoC are registered.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove reset code from the machine code

Now that the transition is over and that we probe our reset driver in every
case, we can remove the legacy code from the machine directory.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove poweroff DT probing

Now that the poweroff code is a driver of its own, remove the DT probing in
mach-at91 and let the usual DT code do its job.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Register the poweroff driver

Register the poweroff driver in the old-style SoC definition so that the driver
is loaded and provide a shutdown hook.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove poweroff code

Now that all the SoC have been converted to use the new poweroff driver, we can
remove the poweroff code defined in mach-at91.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/pm: Remove show_reset_status function

Both the reset and poweroff drivers are now implementing what the
show_reset_status function used to do. Hence, we can remove this rather hackish
function that prevents us from doing further cleanup.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove rstc and shdwnc global base addresses

Now that there's no user left for the global variables holding the reset and
shutdown controllers base address, we can remove these variables and their
associated mapping function.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: Remove rstc and shdwc headers

These headers used to provide an "API" to access the rstc and shdwc registers.
Now that no-one uses this API anymore, we can safely remove those.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>