Thread (38 messages) 38 messages, 8 authors, 2014-07-16

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

From: Tuomas Tynkkynen <hidden>
Date: 2014-07-11 17:21:34
Also in: linux-devicetree, linux-pm, linux-tegra, lkml


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

-- 
nvpublic
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help