[PATCH v3 1/2] DT: pinctrl: Add binding documentation for Spreadtrum pin controller

[Baolin Wang]

This patch adds the binding documentation for Spreadtrum SC9860 pin
controller device.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxx>
---
Changes since v2:
 - No updates.

Changes since v1:
 - Remove magic numbers and get to use the standard bindings.
 - Fix some typos.
---
 .../devicetree/bindings/pinctrl/sprd,pinctrl.txt   |   56 +++++++++++++++++
 .../bindings/pinctrl/sprd,sc9860-pinctrl.txt       |   66 ++++++++++++++++++++
 2 files changed, 122 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/sprd,pinctrl.txt
 create mode 100644 Documentation/devicetree/bindings/pinctrl/sprd,sc9860-pinctrl.txt

diff --git a/Documentation/devicetree/bindings/pinctrl/sprd,pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/sprd,pinctrl.txt
new file mode 100644
index 0000000..2f544cd
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/sprd,pinctrl.txt
@@ -0,0 +1,56 @@
+* Spreadtrum Pin Controller
+
+The Spreadtrum pin controller are organized in 3 blocks (types).
+
+The first block comprises some global control registers, and each
+register contains several bit fields with one bit or several bits
+to configure for some global common configuration, such as domain
+pad driving level, system control select and so on. We recognise
+every fields comprising one bit or several bits in one global control
+register as one pin, thus we should record every pin's bit offset,
+bit width and register offset to configure this field (pin). Since
+this type pins' configuration are very tricky and different for each
+register, we introduce "sprd,ctrl" property to set the various global
+control configuration.
+
+The second block comprises some common registers which have unified
+register definition, and each register described one pin is used
+to configure the pin sleep mode and function select. Now we have 4
+systems on SC9860 SoC: AP system, PUBCP system, TGLDSP system and
+AGDSP system. In some situation we have some pin-sleep related
+configuration need to set when one of system goes into deep sleep
+mode. For example, if we set the pin sleep mode as AP_SLEEP, which
+means when AP system goes into deep sleep mode, this pin's sleep
+related properties (input/output or pullup/down) will be set
+automatically. Thus we intoduce "sprd,sleep_mode" to set pin sleep
+mode.
+
+The last block comprises some misc registers which also have unified
+register definition, and each register described one pin is used to
+configure drive strength, pull up/down and so on. Especially for pull
+up, we introduce "sprd,pullup" property for two kind configuration:
+PULLUP_20K or PULLUP_4_7K, which means the pullup resistor is 20K or
+4.7K.
+
+Required properties for Spreadtrum pin controller:
+- compatible: "sprd,<soc>-pinctrl"
+  Please refer to each sprd,<soc>-pinctrl.txt binding doc for supported SoCs.
+- reg: The register address of pin controller device.
+- pins : An array of pin names.
+
+Optional properties:
+- function: Specified the function name.
+- drive-strength: Drive strength in mA.
+- input-schmitt-disable: Enable schmitt-trigger mode.
+- input-schmitt-enable: Disable schmitt-trigger mode.
+- bias-disable: Disable pin bias.
+- bias-pull-down: Pull down on pin.
+- sprd,ctrl: Control values referring to databook for global control pins.
+- sprd,sleep_mode: Sleep mode selection.
+- sprd,pullup: Pull up on pin.
+- sprd,input-sleep: Input enable when system goes into deep sleep mode.
+- sprd,output-sleep: Output enable when system goes into deep sleep mode.
+- sprd,pullup_sleep: Pull up enable when system goes into deep sleep mode.
+- sprd,pulldown_sleep: Pull down enable when system goes into deep sleep mode.
+
+Please refer to each sprd,<soc>-pinctrl.txt binding doc for supported values.
diff --git a/Documentation/devicetree/bindings/pinctrl/sprd,sc9860-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/sprd,sc9860-pinctrl.txt
new file mode 100644
index 0000000..10b77e1
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/sprd,sc9860-pinctrl.txt
@@ -0,0 +1,66 @@
+* Spreadtrum SC9860 Pin Controller
+
+Please refer to sprd,pinctrl.txt in this directory for common binding part
+and usage.
+
+Required properties:
+- compatible: Must be "sprd,sc9860-pinctrl".
+- reg: The register address of pin controller device.
+- pins : An array of strings, each string containing the name of a pin.
+
+Optional properties:
+- function: A string containing the name of the function, values must be
+  one of: "func1", "func2", "func3" and "func4".
+- drive-strength: Drive strength in mA. Supported values: 2, 4, 6, 8, 10,
+  12, 14, 16, 20, 21, 24, 25, 27, 29, 31 and 33.
+- input-schmitt-disable: Enable schmitt-trigger mode.
+- input-schmitt-enable: Disable schmitt-trigger mode.
+- bias-disable: Disable pin bias.
+- bias-pull-down: Pull down on pin.
+- sprd,ctrl: Control values referring to databook for global control pins.
+- sprd,sleep_mode: Choose the pin sleep mode, and supported values are:
+  AP_SLEEP, PUBCP_SLEEP, TGLDSP_SLEEP and AGDSP_SLEEP.
+- sprd,pullup: Pull up on pin, the value should be PULLUP_20K or PULLUP_4_7K.
+- sprd,input-sleep: Input enable when system goes into deep sleep mode.
+- sprd,output-sleep: Output enable when system goes into deep sleep mode.
+- sprd,pullup_sleep: Pull up enable when system goes into deep sleep mode.
+- sprd,pulldown_sleep: Pull down enable when system goes into deep sleep mode.
+
+Pin sleep mode definition:
+enum pin_sleep_mode {
+	AP_SLEEP = BIT(0),
+	PUBCP_SLEEP = BIT(1),
+	TGLDSP_SLEEP = BIT(2),
+	AGDSP_SLEEP = BIT(3),
+};
+
+Pin pullup mode definition:
+enum pin_pullup_sel {
+	PULLUP_20K,
+	PULLUP_4_7K,
+};
+
+Example:
+pin_controller: pinctrl@402a0000 {
+	compatible = "sprd,sc9860-pinctrl";
+	reg = <0x402a0000 0x10000>;
+
+	grp1: sd0 {
+		pins = "SC9860_VIO_SD2_IRTE", "SC9860_VIO_SD0_IRTE";
+		sprd,ctrl = <0x1>;
+	};
+
+	grp2: rfctl_33 {
+		pins = "SC9860_RFCTL33";
+		function = "func2";
+		sprd,sleep_mode = <AP_SLEEP | PUBCP_SLEEP>;
+		sprd,output-sleep;
+	};
+
+	grp3: rfctl_misc_20 {
+		pins = "SC9860_RFCTL20_MISC";
+		drive-strength = <10>;
+		sprd,pullup = <PULLUP_4_7K>;
+		sprd,pullup-sleep;
+	};
+};
-- 
1.7.9.5