Re: [PATCH 01/13] clk: tegra: Add binding for the Tegra124 DFLL clocksource

Andrew Bresticker
2014-07-11T17:08:55Z

On Fri, Jul 11, 2014 at 9:48 AM, Tuomas Tynkkynen <ttynkkynen@nvidia.com> wrote:
>
>
> On 11/07/14 19:28, Andrew Bresticker wrote:
>>
>> On Thu, Jul 10, 2014 at 2:42 PM, Tuomas Tynkkynen <ttynkkynen@nvidia.com>
>> wrote:
>>>
>>> The DFLL is the main clocksource for the fast CPU cluster on Tegra124
>>> and also provides automatic CPU rail voltage scaling as well. The DFLL
>>> is a separate IP block from the usual Tegra124 clock-and-reset
>>> controller, so it gets its own node in the device tree.
>>
>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/clock/nvidia,tegra124-dfll.txt
>>> b/Documentation/devicetree/bindings/clock/nvidia,tegra124-dfll.txt
>>
>>
>>> +- nvidia,pmic-voltage-table: Array of 2-tuples. Each entry should have
>>> the
>>> + form <register-value voltage-in-uV>, indicating the register value
>>> that
>>> + needs to be programmed to the PMIC for changing the VDD_CPU voltage to
>>> + the specified voltage. The table must be in ascending order by the
>>> voltage.
>>
>>
>> Instead of listing the register values for each voltage in the DT,
>> can't you use regulator_list_voltage() to create this map?
>>
>
> I don't see a way to get the register values that way, unless we assume that
> the mapping is linear and doesn't have holes.

Hmm... I guess if you don't assume it's linear and continuous you'd
have to iterate over all 256 selectors.