[U-Boot] video: ipu_common: fix build error

[Peng Fan]

Hi Eric,
On Mon, Sep 04, 2017 at 07:48:56PM -0700, Eric Nelson wrote:
>Hi Peng,
>
>Can you tell that I'm hunting a bug in an old version?
>
>I'm seeing a **very** intermittent regression between U-Boot
>versions 2015.07 and 2016.05 and happened to spot something
>in this patch.
>
>On 04/27/2016 07:07 PM, Peng Fan wrote:
>>Some toolchains fail to build
>>"clk->rate = (u64)(clk->parent->rate * 16) / div;"
>>And the cast usage is wrong.
>>
>>Use the following code to fix the issue,
>>"
>>   do_div(parent_rate, div);
>>   clk->rate = parent_rate;
>>"
>>
>>Reported-by: Peter Robinson <pbrobinson at gmail.com>
>>Signed-off-by: Peng Fan <van.freenix at gmail.com>
>>Cc: Stefano Babic <sbabic at denx.de>
>>Cc: Fabio Estevam <fabio.estevam at nxp.com>
>>Cc: Tom Rini <trini at konsulko.com>
>>Cc: Anatolij Gustschin <agust at denx.de>
>>Cc: Peter Robinson <pbrobinson at gmail.com>
>>Reviewed-by: Tom Rini <trini at konsulko.com>
>>Tested-by: Peter Robinson <pbrobinson at gmail.com>
>>---
>>
>>Hi Peter,
>>
>>  Please help test this patch to see whether this fix your issue or not.
>>  Thanks for pointing out this issue.
>>
>>Thanks,
>>Peng.
>>
>>  drivers/video/ipu_common.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>>diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
>>index 36d4b23..5676a0f 100644
>>--- a/drivers/video/ipu_common.c
>>+++ b/drivers/video/ipu_common.c
>>@@ -352,7 +352,9 @@ static int ipu_pixel_clk_set_rate(struct clk *clk, unsigned long rate)
>>  	 */
>>  	__raw_writel((div / 16) << 16, DI_BS_CLKGEN1(clk->id));
>
>Did we lose a multiply by 16 in this change?

We already have "parent_rate = (unsigned long long)clk->parent->rate * 16;"
in this function.

Thanks,
Peng.

>
>>-	clk->rate = (u64)(clk->parent->rate * 16) / div;
>>+	do_div(parent_rate, div);
>>+
>>+	clk->rate = parent_rate;
>>  	return 0;
>>  }
>>
>
>Please advise,
>
>
>Eric