timer resolution of ~32us is pretty low.
v2 has 32bits resolution, so we have quite some headroom, and
can use the 24MHz clock.
v1 has only 16bits, so we only increase v2.
So we just exchange the timrot clock in imx28.
On imx23 we have timrotv1 and everything stays the same.
Signed-off-by: Torben Hohn <torbenh@linutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Setup scheduler clock on ARM MXS platforms with a 32-bit timrot
such as i.MX28. This allows the scheduler to use sub-jiffy resolution.
The corresponding change for 16-bit v1 timrots is not possible
at the moment due to rounding issues with clock values wrapping
faster than once per several seconds in the common ARM platform code.
Signed-off-by: Stanislav Meduna <stano@meduna.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Rather than using the static timer irq definition, we should retrieve
timer irq from device tree for better.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
With old mxs clock support removed, the timer_clk argument of
mxs_timer_init is unused now, so remove it.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
When mxs_timer_init() does not have a timer_clk passed in, it should
try to request clock from clkdev system.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
The patch converts mxs platform code to clk_prepare/clk_unprepare
by using helper functions clk_prepare_enable/clk_disable_unprepare.
Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
There are 2 versions of the timrot on Freescale MXS-based SoCs.
The v1 on MX23 only gets 16 bits counter, while v2 on MX28
extends the counter to 32 bits.
The implementation uses two timers, one for clock_event and
another for clocksource. MX28 uses timrot 0 and 1, while MX23
uses 0 and 2.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
