Re: [PATCH v2 4/6] soc: mediatek: Add SMI driver

[Daniel Kurtz <djkurtz@google.com>]

On Thu, May 21, 2015 at 3:30 PM, Matthias Brugger
<matthias.bgg@gmail.com> wrote:
> 2015-05-21 8:16 GMT+02:00 Yong Wu <yong.wu@mediatek.com>:
>> Hi Matthias,
>>      Thanks very much for your suggestion.
>>      Abort the smi clock name, Could you help check below.
>>      The others I will improve in next time.
>>
>> On Tue, 2015-05-19 at 13:14 +0200, Matthias Brugger wrote:
>>> 2015-05-15 11:43 GMT+02:00 Yong Wu <yong.wu@mediatek.com>:
>>> >     This patch add SMI(Smart Multimedia Interface) driver. This driver is
>>> > responsible to enable/disable iommu and control the clocks of each local arbiter.
>>> >
>> [snip]
>>> > +
>>> > +#define SMI_LARB_MMU_EN                (0xf00)
>>> > +#define F_SMI_MMU_EN(port)     (1 << (port))
>>> > +
>>> > +enum {
>>> > +       MTK_CLK_APB,
>>> > +       MTK_CLK_SMI,
>>> > +       MTK_CLK_MAX,
>>>
>>> Maybe add something like:
>>> MTK_CLK_FIRST = MTK_CLK_APB,
>>> to make the for loops better readable.
>>>
>> Then, Is it like this? :
>>  enum {
>>         MTK_CLK_FIRST = MTK_CLK_APB,
>>         MTK_CLK_SMI,
>>         MTK_CLK_MAX,
>>  }
>> or the CLK_SMI also need MTK_CLK_SECOND = MTK_CLK_SMI.
>
>
> something like:
> enum {
>          MTK_CLK_FIRST,
>          MTK_CLK_APB = MTK_CLK_FIRST,
>          MTK_CLK_SMI,
>          MTK_CLK_LAST,
> }
>
> So you can rewrite the for loop:
> if (i = MTK_CLK_FIRST; i < MTK_CLK_LAST; i++)

Actually, do we ever plan to add more clks per smi node?
If not, perhaps the whole driver would be simpler if you just
explicitly handle the apb & smi clocks:

struct mtk_smi_larb {
       void __iomem            *base;
       spinlock_t              portlock; /* lock for config port */
       struct device           *smi;
       struct clk              *clk_apb;
       struct clk              *clk_smi;
};

And then all of the loops become just a pair of clock operations.

Best Regards,
-Dan

>
> Regards,
> Matthias
>
>>> > +};
>>> > +
>>> > +struct mtk_smi_common {
>>> > +       void __iomem            *base;
>>>
>>> That seems to be never used. Please delete it.
>>>
>>> > +       struct clk              *clk[MTK_CLK_MAX];
>>> > +};
>>> > +
>>> > +struct mtk_smi_larb {
>>> > +       void __iomem            *base;
>>> > +       spinlock_t              portlock; /* lock for config port */
>>> > +       struct clk              *clk[MTK_CLK_MAX];
>>> > +       struct device           *smi;
>>> > +};
>>> > +
>>> Thanks,
>>> Matthias
>>
>>
>
>
>
> --
> motzblog.wordpress.com



-- 
Daniel Kurtz | Software Engineer | djkurtz@google.com | 650.204.0722