Currently the clocksource and clockevent support for davinci platforms
lives in mach-davinci. It hard-codes many things, uses global variables,
implements functionalities unused by any platform and has code fragments
scattered across many (often unrelated) files.

Implement a new, modern and simplified timer driver and put it into
drivers/clocksource. We still need to support legacy board files so
export a config structure and a function that allows machine code to
register the timer.

The timer we're using is 64-bit but can be programmed in dual 32-bit
mode (both chained and unchained).

On all davinci SoCs except for da830 we're using both halves. Lower half
for clockevents and upper half for clocksource. On da830 we're using the
lower half for both with the help of a compare register.

This patch contains the core code and support for clockevent. The
clocksource code will be included in a subsequent patch.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

The system counter (sys_ctr) is a programmable system counter
which provides a shared time base to the Cortex A15, A7, A53 etc cores.
It is intended for use in applications where the counter is always
powered on and supports multiple, unrelated clocks. The sys_ctr hardware
supports:
 - 56-bit counter width (roll-over time greater than 40 years)
 - compare frame(64-bit compare value) contains programmable interrupt
   generation when compare value <= counter value.

[dlezcano] Fixed over 80 chars length warning

Signed-off-by: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Remove build dependency on ARM for compile-testing to allow non-arch
specific build-bots (like Intel's test robot) to compile the driver and
report about problems.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull clocksource updates from Ingo Molnar:
 "Misc clocksource/clockevent driver updates that came in a bit late but
  are ready for v5.2"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  misc: atmel_tclib: Do not probe already used TCBs
  clocksource/drivers/timer-atmel-tcb: Convert tc_clksrc_suspend|resume() to static
  clocksource/drivers/tcb_clksrc: Rename the file for consistency
  clocksource/drivers/timer-atmel-pit: Rework Kconfig option
  clocksource/drivers/tcb_clksrc: Move Kconfig option
  ARM: at91: Implement clocksource selection
  clocksource/drivers/tcb_clksrc: Use tcb as sched_clock
  clocksource/drivers/tcb_clksrc: Stop depending on atmel_tclib
  ARM: at91: move SoC specific definitions to SoC folder
  clocksource/drivers/timer-milbeaut: Cleanup common register accesses
  clocksource/drivers/timer-milbeaut: Add shutdown function
  clocksource/drivers/timer-milbeaut: Fix to enable one-shot timer
  clocksource/drivers/tegra: Rework for compensation of suspend time
  clocksource/drivers/sp804: Add COMPILE_TEST to CONFIG_ARM_TIMER_SP804
  clocksource/drivers/sun4i: Add a compatible for suniv
  dt-bindings: timer: Add Allwinner suniv timer

Merge in a few pending fixes from pre-5.1 that didn't get sent in:

MAINTAINERS: update arch/arm/mach-davinci
ARM: dts: ls1021: Fix SGMII PCS link remaining down after PHY disconnect
ARM: dts: imx6q-logicpd: Reduce inrush current on USBH1
ARM: dts: imx6q-logicpd: Reduce inrush current on start
ARM: dts: imx: Fix the AR803X phy-mode
ARM: dts: sun8i: a33: Reintroduce default pinctrl muxing
arm64: dts: allwinner: a64: Rename hpvcc-supply to cpvdd-supply
ARM: sunxi: fix a leaked reference by adding missing of_node_put
ARM: sunxi: fix a leaked reference by adding missing of_node_put

Signed-off-by: Olof Johansson <olof@lixom.net>

Allow building the PIT driver when COMPILE_TEST is enabled. Also remove its
default value so it can be disabled.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Move the ATMEL_TCB_CLKSRC option to drivers/clocksource and make it silent
if COMPILE_TEST is not selected.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

This is only used on arm and arm64 platforms. Add COMPILE_TEST option.

Tested with 5.1-rc3+ on Fedora/RISCV. CONFIG_ARM_TIMER_SP804 no more shows
up in riscv config.

Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

This adds a new slightly rewritten timer driver for the
Intel IXP4xx clocksource, clockevent and delay timer.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>