On Fri, Jul 11, 2014 at 08:21:27PM +0300, Tuomas Tynkkynen wrote:

On 11/07/14 20:08, Andrew Bresticker wrote:

quoted

On Fri, Jul 11, 2014 at 9:48 AM, Tuomas Tynkkynen [off-list ref] wrote:

quoted

On 11/07/14 19:28, Andrew Bresticker wrote:

quoted

On Thu, Jul 10, 2014 at 2:42 PM, Tuomas Tynkkynen [off-list ref]
wrote:

quoted

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.

quoted

diff --git
a/Documentation/devicetree/bindings/clock/nvidia,tegra124-dfll.txt
b/Documentation/devicetree/bindings/clock/nvidia,tegra124-dfll.txt

quoted

+- 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.

I don't think we can assume that each selector maps to a concrete register
value, though I'm not sure. include/linux/regulator/driver.h documents for
@list_voltage "Selectors range from zero to one less
regulator_desc.n_voltages." but maybe the consumer API could take different
values.

I don't think the regulator API makes any guarantees that the selector
corresponds to a register value. Adding Mark Brown, maybe he can help
figure out the best way to do this.

Thierry