Hi,
Thanks for this info.
Regards,
Archit
Nayak, Rajendra wrote:
> Archit,
>
>> -----Original Message-----
>> From: Taneja, Archit
>> Sent: Friday, September 24, 2010 6:11 PM
>> To: Nayak, Rajendra
>> Cc: linux-omap@xxxxxxxxxxxxxxx; Guruswamy, Senthilvadivu
>> Subject: Query on clock naming conventions in clockxxxx_data.c
>>
>> Hi,
>>
>> I had a couple of queries regarding the clock structures in the
>> clockxxxx_data.c files:
>>
>> -I have seen that the name of the structure itself explains the name
>> of the clock as given in the TRM.
>> -The member "name" also tries to mimic the clock name.
>>
>> The drivers get the clock struct using the "name" member in the
>> clk_get() api. Is it okay if we can change the "name" member to a more
>> generic string. So that the driver code stays more generic?
>>
>> For example, the SYS_CLK which comes into DSS is called "dss2_alwon_fck" on
>> omap3 and
>> "dss_sys_clk" on omap4. This will make our driver need to have
>> cpu_is_omap checks while calling clk_get().
>
> The right way to use the clk_get api is by passing the dev
> pointer to identify the device and a generic identifier like
> fck or ick to identify the type/functionality of the clock.
> Its not advisable to hardcode clock names, the very reason
> being that it gets difficult to maintain clock node names
> across processor families and eventually you end up with cpu_is_* checks.
>
> Doing this however requires the clkdev tables to be updated
> with the mapping of device names and generic clock
> identifiers to the actual clock node.
>
> So if you today have something like
> if (cpu_is_omap34xx())
> clk_get(NULL, " dss2_alwon_fck");
> else
> clk_get(NULL, " dss_sys_clk");
>
> It can very easily be replaced with a
> clk_get(dev, "fck");
>
> with the clkdev table entry for omap3 like
> CLK("dss-omap","fck", &dss2_alwon_fck...
> and the clkdev table entry for omap4 having something like
> CLK("dss-omap","fck", & dss_sys_clk...
>
> Now, however since all drivers are using pm_runtime api's
> which hide the clk control from drivers, this might not have be needed anyway.
>
> Regards,
> Rajendra
>
>>
>> Thanks,
>>
>> Archit--
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