[PATCH v8 1/6] mfd: AXP20x: Add bindings documentation

[Chen-Yu Tsai]

From: Carlo Caione <carlo at caione.org>

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

Signed-off-by: Carlo Caione <carlo at caione.org>
Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
[wens at csie.org: clarify interrupt source for the axp PMIC]
[wens at csie.org: explain dcdc-workmode in detail and trim lines to 80 chars]
[wens at csie.org: make regulator supplies optional if using unregulated input]
[wens at csie.org: use cubieboard2 regulator nodes as example]
Signed-off-by: Chen-Yu Tsai <wens at csie.org>
---
 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
+
+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
+			  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 at 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 */
+		};
+
+		csi1_io_2v8: ldo4 {
+			/* output on extension headers */
+			regulator-name = "csi1-io-2v8";
+		};
+	};
+};
+
-- 
2.1.4