Re: [PATCH 01/26] ARM: OMAP: dmtimer: Remove setting of clk parent indirectly through platform hook

From: Joel Fernandes
Date: Wed May 07 2014 - 18:09:16 EST


On 05/07/2014 05:04 PM, Tony Lindgren wrote:
> * Joel Fernandes <joelf@xxxxxx> [140507 14:44]:
>> On 05/07/2014 10:19 AM, Tony Lindgren wrote:
>>> * Joel Fernandes <joelf@xxxxxx> [140424 14:44]:
>>>> There is a platform specific hook just for OMAP1 to set its clk parent. Remove
>>>> this hook and have OMAP1 set its parent in omap1_dm_timer_init. If OMAP1 is
>>>> ever migrated to clock framework, the correct way to do this would be through
>>>> clk_set_parent like other platforms.
>>>>
>>>> Signed-off-by: Joel Fernandes <joelf@xxxxxx>
>>>> ---
>>>> arch/arm/mach-omap1/timer.c | 8 +++++++-
>>>> arch/arm/plat-omap/dmtimer.c | 8 +++-----
>>>> include/linux/platform_data/dmtimer-omap.h | 2 --
>>>> 3 files changed, 10 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/arch/arm/mach-omap1/timer.c b/arch/arm/mach-omap1/timer.c
>>>> index bde7a35..4b9c604 100644
>>>> --- a/arch/arm/mach-omap1/timer.c
>>>> +++ b/arch/arm/mach-omap1/timer.c
>>>> @@ -140,7 +140,13 @@ static int __init omap1_dm_timer_init(void)
>>>> goto err_free_pdata;
>>>> }
>>>>
>>>> - pdata->set_timer_src = omap1_dm_timer_set_src;
>>>> + /*
>>>> + * Since OMAP1 doesn't support clock framework, set timer clock
>>>> + * source to 32KHz here instead of expecting it to be set by
>>>> + * dmtimer code.
>>>> + */
>>>> + omap1_dm_timer_set_src(pdev, 0x01);
>>>> +
>>>> pdata->timer_capability = OMAP_TIMER_ALWON |
>>>> OMAP_TIMER_NEEDS_RESET | OMAP_TIMER_HAS_DSP_IRQ;
>>>>
>>>
>>> This does not sound right, omap1 does support clock framework just fine.
>>> It is not using the common clock framework though.
>>>
>>> This breaks omap_dm_timer_set_source() for sure. Setting the source
>>> during init is not a right solution here. Probably best to keep the
>>> pdata hook around, drivers can support pdata and DT data together
>>> just fine.
>>
>> Actually pdata hook in this case is used only in 1 place, and is OMAP1
>> specific so I felt its better to clean it up.
>>
>> Can you elaborate a bit more on why it breaks? I have no way of testing
>> OMAP1 without hardware.
>>
>> What difference is it to set MOD_CONF_CTRL_1 in omap1's
>> arch_initcall(omap1_dm_timer_init) versus doing so later?
>
> You're making a driver behave in a different way for omap1
> compared to omap2+ where selecting the clock source won't work
> for omap1.

Ok, I'll drop this patch and leave the hook as-is. Thanks.

Regards,
-Joel

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