Documentation: Add device tree bindings for Samsung PWM timers

This patch adds missing documentation describing Device Tree bindings
for Samsung PWM timers.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Let platforms select the driver

This patch modifies the way of enabling the driver to let the platforms
select it in their Kconfig instead of specifying particular platforms in
Kconfig entry of the driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Make PWM spinlock global

This patch makes the PWM spinlock global and exports it to allow using
it in Samsung PWM driver (will be reworked to use proper synchronization
in further patches).

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Keep all driver data in a structure

This patch modifies the driver to keep all its private data consistently
in a single struct, instead of keeping part as separate variables.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct

This patch removes the unused samsung_pwm struct from public header.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Add support for non-DT platforms

This patch extends the driver to support platforms that still use legacy
ATAGS-based boot, without device tree, by providing an exported function
that can be used from platform code to initialize the clocksource.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
clocksource: samsung_pwm_timer: Use proper clockevents max_delta

This patch replaces hardcoded -1 argument passed to
clockevents_config_and_register() with tcnt_max calculated based on
variant data.

This fixes invalid max delta configuration for 16-bit timers of s3c24xx.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Correct programming of clock events

In current code, the tick count value programmed to the hardware is
always decremented by one. This is reasonable for periodic mode, since
there is one extra tick between 0 and COUNT (after reloading), but it
makes oneshot events happen 1 tick earlier than requested, because the
interrupt is triggered on transition from 1 to 0.

This patch removes the decrementation from PWM channel setup code and
moves it instead to periodic timer setup, to make both periodic and
oneshot modes work correctly.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core

Due to rounding errors in clockevents core (in conversions between ticks
and nsecs), it might happen that the set_next_event callback gets called
with cycles = 0, causing the code to incorrectly program the PWM timer.

This patch modifies the callback to program the timer for 1 tick, if
received tick count value is 0.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos

This patch removes legacy PWM timer interrupt initialization from
exynos{4,5}_init_irq() functions, since it conflicts with internal
interrupt handling of the new PWM clocksource driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ARM: EXYNOS: Fix support of Exynos4210 rev0 SoC

This patch extends exynos_init_time() function to handle Exynos4210 rev0
SoC, which differs in availability of system timers and needs different
clocksource initialization.

This makes it possible to use exynos_init_time() function as init_time
callback for all Exynos-based boards, including Universal_C210, which
originally had to use samsung_timer_init().

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ARM: dts: exynos4: Add node for PWM device

This patch adds device tree node for PWM block present on Exynos 4 SoCs.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
ARM: dts: exynos4210: Add basic dts file for universal_c210 board

This patch adds basic device tree sources for Universal C210 board.

Currently support includes:
- eMMC
- serial
- max8952 and max8998 voltage regulators.
- gpio-keys

More support will be added in further patches.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>