On Mon, Jan 19, 2015 at 5:37 PM, Lee Jones [off-list ref] wrote:

On Tue, 23 Dec 2014, Chen-Yu Tsai wrote:

quoted

From: Carlo Caione <redacted>

Bindings documentation for the AXP20x driver. In this file also
sub-nodes are documented.

Signed-off-by: Carlo Caione <redacted>
Acked-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
[wens-jdAy2FN1RRM@public.gmane.org: clarify interrupt source for the axp PMIC]
[wens-jdAy2FN1RRM@public.gmane.org: explain dcdc-workmode in detail and trim lines to 80 chars]
[wens-jdAy2FN1RRM@public.gmane.org: make regulator supplies optional if using unregulated input]
[wens-jdAy2FN1RRM@public.gmane.org: use cubieboard2 regulator nodes as example]
Signed-off-by: Chen-Yu Tsai <redacted>
---
 Documentation/devicetree/bindings/mfd/axp20x.txt | 97 ++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/axp20x.txt

diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt
new file mode 100644
index 000000000000..b775d8ccbc7c
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/axp20x.txt

@@ -0,0 +1,97 @@
+AXP202/AXP209 device tree bindings
+
+The axp20x family current members :
+axp202 (X-Powers)
+axp209 (X-Powers)
+
+Required properties:
+- compatible: "x-powers,axp202" or "x-powers,axp209"
+- reg: The I2C slave address for the AXP chip
+- interrupt-parent: The parent interrupt controller
+- interrupts: SoC NMI / GPIO interrupt connected to the PMIC's IRQ pin
+- interrupt-controller: axp20x has its own internal IRQs
+- #interrupt-cells: Should be set to 1
+- regulators: A node that houses a sub-node for each regulator. The regulators
+           are bound using their name as listed here: dcdc2, dcdc3, ldo1,
+           ldo2, ldo3, ldo4, ldo5.  The bindings details of individual
+           regulator device can be found in:
+           Documentation/devicetree/bindings/regulator/regulator.txt with
+           the exception of x-powers,dcdc-freq. Regulators not used should
+           still be listed for completeness and that the regulator subsystem
+           properly registers them.
+
+- x-powers,dcdc-freq: defines the work frequency of DC-DC in KHz
+                   (range: 750-1875). Default: 1.5MHz

I'm not keen on defining new properties when existing properties would
suffice.  How about using clock-frequency here instead?  Also it's not
common to issue this stuff using metric prefixes (KHz, MHz, etc).
Please use HZ.

I was a bit worried about conflicts later on with things like ADC
sampling rates. But I guess that would be in a separate sub-node.
So yeah, using clock-frequencies should work out. Same for the
prefix. I'll add a patch to fix axp209.dtsi that was merged.

quoted

+Optional properties:
+- regulator supplies - may be omitted if inputs are unregulated, such as using
+                    the IPSOUT output from the PMIC
+  - acin-supply: The input supply for LDO1
+  - vin2-supply: The input supply for DCDC2
+  - vin3-supply: The input supply for DCDC3
+  - ldo24in-supply: The input supply for LDO2, LDO4
+  - ldo3in-supply: The input supply for LDO3
+  - ldo5in-supply: The input supply for LDO5
+
+Optional properties for DCDC regulators:
+- x-powers,dcdc-workmode: 1 for PWM mode, 0 for AUTO (PWM/PFM) mode

If there only two options, please use bool.

'x-powers,dcdc-workmode-pwm' and default to auto if it's not present.

OK. Adding another regulator patch for this.

quoted

+                       Default: AUTO mode
+                       The DCDC regulators work in a mixed PWM/PFM mode,
+                       using PFM under light loads and switching to PWM
+                       for heavier loads. Forcing PWM mode trades efficiency
+                       under light loads for lower output noise. This
+                       probably makes sense for HiFi audio related
+                       applications that aren't battery constrained.
+
+Example:
+
+axp209: pmic@34 {
+     compatible = "x-powers,axp209";
+     reg = <0x34>;
+     interrupt-parent = <&nmi_intc>;
+     interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
+     interrupt-controller;
+     #interrupt-cells = <1>;
+
+     regulators {
+             x-powers,dcdc-freq = <1500>;
+
+             vdd_cpu: dcdc2 {
+                     regulator-always-on;
+                     regulator-min-microvolt = <1000000>;
+                     regulator-max-microvolt = <1450000>;
+                     regulator-name = "vdd-cpu";
+             };
+
+             vdd_int_dll: dcdc3 {
+                     regulator-always-on;
+                     regulator-min-microvolt = <1000000>;
+                     regulator-max-microvolt = <1400000>;
+                     regulator-name = "vdd-int-dll";
+             };
+
+             vdd_rtc: ldo1 {
+                     regulator-always-on;
+                     regulator-min-microvolt = <1200000>;
+                     regulator-max-microvolt = <1400000>;
+                     regulator-name = "vdd-rtc";
+             };
+
+             avcc: ldo2 {
+                     regulator-always-on;
+                     regulator-min-microvolt = <2700000>;
+                     regulator-max-microvolt = <3300000>;
+                     regulator-name = "avcc";
+             };
+
+             ldo3 {
+                     /* unused */
+             };

Does this need to be in the example?

This follows the bit in the bindings saying that _all_ regulators
should be listed, even unused ones, so the regulator subsystem
can do cleanup.

quoted

+             csi1_io_2v8: ldo4 {
+                     /* output on extension headers */
+                     regulator-name = "csi1-io-2v8";
+             };
+     };

ldo5 is missing here.

quoted

+};
+

Thanks for the review.

Regards,
ChenYu