On Thu, Jul 31, 2014 at 6:42 PM, Matthias Brugger
[off-list ref] wrote:

We enable GTP6 which ungates the arch timer clock. Apart we write the
frequency with which the timer is running in the CNTFREQ register.
In the future this should be done in the bootloader.

Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

(...)

+       if (of_machine_is_compatible("mediatek,mt6589")) {
+               /* set cntfreq register which is not done in bootloader */
+               asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (13000000));

I guess this is for something like the ARM arch timer in
drivers/clocksource/arm_arch_timer.c

Instead of doing this, use the DT property "clock-frequency" on
the ARM arch timer node, as that overrides the CP15 setting.

+
+               /* turn on GPT6 which ungates arch timer clocks */
+               gpt_base = ioremap(GPT6_CON_MT65xx, 0x04);
+       }
+
+       /* enabel clock and set to free-run */
+       if (gpt_base)
+               writel(0x31, gpt_base);

Why is this not done properly in the GPT driver (I guess
in drivers/clocksource/mtk_timer.c) instead of remapping
it and fiddling around in the machine?

If it only affects the mt6589 just add another compatible string
to that driver like "mediatek,mt6589-timer" as it properly reflects the
fact that this timer is slightly different on the 6589.

Also use a #define for the magic constant 0x31.

Yours,
Linus Walleij