On Tue, Aug 12, 2014 at 11:02 AM, Matthias Brugger
<matthias.bgg@xxxxxxxxx> wrote:
> 2014-08-11 9:15 GMT+02:00 Linus Walleij <linus.walleij@xxxxxxxxxx>:
>> On Thu, Jul 31, 2014 at 6:42 PM, Matthias Brugger
>> <matthias.bgg@xxxxxxxxx> 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@xxxxxxxxx>
>> (...)
>>
>>> + 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?
>
> I didn't put it in the GPT driver, because that would mean, that you
> need to have the mtk_timer to be able to use the ARM arch timer.
> From my understanding this are two independent blocks in the SoC.
> Apart from that, as stated in the commit message, this patch is a
> workaround until we have a bootloader which does this for us.
> Therefore I thought the init_time function would be the better place to do this.
OK I get the point...
What about the ARM arch timer fixup then, will that also be
fixed in the boot loader eventually?
Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
