[U-Boot] [U-Boot,2/3] imx: mx6: correct IPU clock

[Ye Li]

On 9/5/2017 6:33 PM, Eric Nelson wrote:
> Hi Peng,
>
> Pardon the reference to an old update, but do you have a description
> of the symptoms that brought about this patch?
>
> On 03/09/2016 01:07 AM, Peng Fan wrote:
>> The CONFIG_IPUV3_CLK should be 264000000, to i.MX6DL, it should be
>> 198000000.
>>
>> Signed-off-by: Peng Fan <van.freenix at gmail.com>
>> Signed-off-by: Sandor Yu <sandor.yu at nxp.com>
>> Cc: Stefano Babic <sbabic at denx.de>
>> Cc: Fabio Estevam <fabio.estevam at nxp.com>
>> Cc: Peter Robinson <pbrobinson at gmail.com>
>> ---
>>    include/configs/mx6sabre_common.h | 6 +++++-
>>    1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/configs/mx6sabre_common.h b/include/configs/mx6sabre_common.h
>> index 29d1f91..a6d821b 100644
>> --- a/include/configs/mx6sabre_common.h
>> +++ b/include/configs/mx6sabre_common.h
>> @@ -225,7 +225,11 @@
>>    #define CONFIG_BMP_16BPP
>>    #define CONFIG_VIDEO_LOGO
>>    #define CONFIG_VIDEO_BMP_LOGO
>> -#define CONFIG_IPUV3_CLK 260000000
>> +#ifdef CONFIG_MX6DL
>> +#define CONFIG_IPUV3_CLK 198000000
>> +#else
>> +#define CONFIG_IPUV3_CLK 264000000
>> +#endif
>
>
> Note that this should probably be applied for other boards
> which are compiled for multiple CPU types.
>
> At least the Boundary Nitrogen boards, but probably others
> like Wand have ordering options for DL or Solo processors
> and may need the reduced clock rate.
>
>
>>    #define CONFIG_IMX_HDMI
>>    #define CONFIG_IMX_VIDEO_SKIP
>>
>
> Please advise,
>
>
> Eric
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>

CONFIG_IPUV3_CLK is used to indicate the default rate for IPU HSP clock. 
The IPU driver in u-boot won't calculate the HSP clock rate according to 
CCM registers, it needs this setting to know current rate. 198Mhz is the 
correct value on DL not the 264Mhz.

If you select IPU DI clock (pixel clock) derived from HSP clock not the 
external clock like LDB DI clock, I believe the 264Mhz will cause problem.

Best regards,
Ye Li