pinctrl: add pinctrl driver for Rockchip SoCs

This driver adds support the Cortex-A9 based SoCs from Rockchip,
so at least the RK2928, RK3066 (a and b) and RK3188.
Earlier Rockchip SoCs seem to use similar mechanics for gpio
handling so should be supportable with relative small changes.
Pull handling on the rk3188 is currently a stub, due to it being
a bit different to the earlier SoCs.

Pinmuxing as well as gpio (and interrupt-) handling tested on
a rk3066a based machine.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt
new file mode 100644
index 000000000000..b0fb1018d7ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/rockchip,pinctrl.txt
@@ -0,0 +1,97 @@
+* Rockchip Pinmux Controller
+
+The Rockchip Pinmux Controller, enables the IC
+to share one PAD to several functional blocks. The sharing is done by
+multiplexing the PAD input/output signals. For each PAD there are up to
+4 muxing options with option 0 being the use as a GPIO.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices, including the meaning of the
+phrase "pin configuration node".
+
+The Rockchip pin configuration node is a node of a group of pins which can be
+used for a specific device or function. This node represents both mux and
+config of the pins in that group. The 'pins' selects the function mode(also
+named pin mode) this pin can work on and the 'config' configures various pad
+settings such as pull-up, etc.
+
+The pins are grouped into up to 5 individual pin banks which need to be
+defined as gpio sub-nodes of the pinmux controller.
+
+Required properties for iomux controller:
+  - compatible: one of "rockchip,rk2928-pinctrl", "rockchip,rk3066a-pinctrl"
+		       "rockchip,rk3066b-pinctrl", "rockchip,rk3188-pinctrl"
+
+Required properties for gpio sub nodes:
+  - compatible: "rockchip,gpio-bank"
+  - reg: register of the gpio bank (different than the iomux registerset)
+  - interrupts: base interrupt of the gpio bank in the interrupt controller
+  - clocks: clock that drives this bank
+  - gpio-controller: identifies the node as a gpio controller and pin bank.
+  - #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO
+    binding is used, the amount of cells must be specified as 2. See generic
+    GPIO binding documentation for description of particular cells.
+  - interrupt-controller: identifies the controller node as interrupt-parent.
+  - #interrupt-cells: the value of this property should be 2 and the interrupt
+    cells should use the standard two-cell scheme described in
+    bindings/interrupt-controller/interrupts.txt
+
+Required properties for pin configuration node:
+  - rockchip,pins: 3 integers array, represents a group of pins mux and config
+    setting. The format is rockchip,pins = <PIN_BANK PIN_BANK_IDX MUX &phandle>.
+    The MUX 0 means gpio and MUX 1 to 3 mean the specific device function.
+    The phandle of a node containing the generic pinconfig options
+    to use, as described in pinctrl-bindings.txt in this directory.
+
+Examples:
+
+#include <dt-bindings/pinctrl/rockchip.h>
+
+...
+
+pinctrl@20008000 {
+	compatible = "rockchip,rk3066a-pinctrl";
+	reg = <0x20008000 0x150>;
+	#address-cells = <1>;
+	#size-cells = <1>;
+	ranges;
+
+	gpio0: gpio0@20034000 {
+		compatible = "rockchip,gpio-bank";
+		reg = <0x20034000 0x100>;
+		interrupts = <GIC_SPI 54 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&clk_gates8 9>;
+
+		gpio-controller;
+		#gpio-cells = <2>;
+
+		interrupt-controller;
+		#interrupt-cells = <2>;
+	};
+
+	...
+
+	pcfg_pull_default: pcfg_pull_default {
+		bias-pull-pin-default
+	};
+
+	uart2 {
+		uart2_xfer: uart2-xfer {
+			rockchip,pins = <RK_GPIO1 8 1 &pcfg_pull_default>,
+					<RK_GPIO1 9 1 &pcfg_pull_default>;
+		};
+	};
+};
+
+uart2: serial@20064000 {
+	compatible = "snps,dw-apb-uart";
+	reg = <0x20064000 0x400>;
+	interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
+	reg-shift = <2>;
+	reg-io-width = <1>;
+	clocks = <&mux_uart2>;
+	status = "okay";
+
+	pinctrl-names = "default";
+	pinctrl-0 = <&uart2_xfer>;
+};