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SubjectRe: [PATCH 1/4] ARM: rockchip: rk3288: Switch to use the proper PWM IP
From
Sonny,

On Mon, Aug 18, 2014 at 10:11 AM, Sonny Rao <sonnyrao@chromium.org> wrote:
> On Mon, Aug 18, 2014 at 10:09 AM, Doug Anderson <dianders@chromium.org> wrote:
>> The rk3288 SoC has an option to switch all of the PWMs in the system
>> between the old IP block and the new IP block. The new IP block is
>> working and tested and the suggested PWM to use, so setup the SoC to
>> use it and then we can pretend that the other IP block doesn't exist.
>>
>> This code could go lots of other places, but we've put it here. Why?
>> - Pushing it to the bootloader just makes the code harder to update in
>> the field. If we later find a bug in the new IP block and want to
>> change our mind about what to use we want it to be easy to update.
>> - Putting this code in the driver for IP block is a lot of extra work,
>> device tree bindings, etc. Now that the new IP block is validated
>> it's likely no future SoCs will need this code. Why pollute the PWM
>> driver with this? This is an rk3288 thing so it should be in rk3288
>> code.
>> - There's a single bit that switches over PWMs, which makes it extra
>> hard to put this under the PWM device tree nodes.
>>
>> Signed-off-by: Doug Anderson <dianders@chromium.org>
>> ---
>> arch/arm/mach-rockchip/rockchip.c | 19 +++++++++++++++++++
>> 1 file changed, 19 insertions(+)
>>
>> diff --git a/arch/arm/mach-rockchip/rockchip.c b/arch/arm/mach-rockchip/rockchip.c
>> index 8ab9e0e..99133b9 100644
>> --- a/arch/arm/mach-rockchip/rockchip.c
>> +++ b/arch/arm/mach-rockchip/rockchip.c
>> @@ -24,6 +24,24 @@
>> #include <asm/hardware/cache-l2x0.h>
>> #include "core.h"
>>
>> +static void __init rk3288_init_machine(void)
>> +{
>> + void *grf = ioremap(0xff770000, 0x10000);
>
> Is it worth checking for failure here? Will the system boot without this?

Yes, the system will boot without it. I can't quite imagine the
ioremap failing, but I can add a test.

-Doug


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