pinctrl: sirf: add sirf atlas7 pinctrl and gpio support

The Pinctrl module (ioc) controls the Pad's function select
(each pad can have 8 functions), Pad's Drive Strength, Pad's
Pull Select and Pad's Input Disable status.

The ioc has two modules, ioc_top & ioc_rtc. Both of these two
modules have function select/clear, Pull select and Drive
Strength registers. But only ioc_rtc has input-disable
registers. The Pads on ioc_top have to access ioc_rtc to set
their input-disable status and intpu-disable-value.

So have to use one ioc driver instance to drive these two
ioc modules at the same time, and each ioc module will be
treat as one bank on the "IOC Device".

The GPIO Controller controls the GPIO status if the Pad has
been config as GPIO by Pinctrl already. Includes the GPIO
Input/output, Interrupt type, Interrupt Status, and Set/Get
Values.
The GPIO pull up/down are controlled by Pinctrl.

There are 7 GPIO Groups and splited into 3 MACROs in atlas7.
The GPIO Groups in one MACRO share one GPIO controllers, each
GPIO Group are treated as one GPIO bank.

For example:
In VDIFM macro, there is one GPIO Controller, it has 3 banks
to control 3 gpio groups. Its gpio name space is from 0 to 95.

The Device Tree can be written as following:

gpio-ranges = <&pinctrl 0 0 0>,
<&pinctrl 32 0 0>,
<&pinctrl 64 0 0>;

gpio-ranges-group-names = "gnss_gpio_grp",
"lcd_vip_gpio_grp",
"sdio_i2s_gpio_grp";

bank#0 is from 0~31, the pins are from pinctrl's "gnss_gpio_grp".
bank#2 is from 32~63, the pins are from pinctrl's "lcd_vip_gpio_grp".
bank#3 is from 64~95, the pins are from pinctrl's "sdio_i2s_gpio_grp".

Signed-off-by: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 109 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-atlas7.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-atlas7.txt
new file mode 100644
index 000000000000..eecf028ff485
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-atlas7.txt
@@ -0,0 +1,109 @@
+CSR SiRFatlas7 pinmux controller
+
+Required properties:
+- compatible	: "sirf,atlas7-ioc"
+- reg		: Address range of the pinctrl registers
+
+For example, pinctrl might have properties like the following:
+	pinctrl: ioc@18880000 {
+			compatible = "sirf,atlas7-ioc";
+			reg = <0x18880000 0x1000>;
+
+			a_ac97_pmx: ac97@0 {
+				ac97 {
+					groups = "audio_ac97_grp";
+					function = "audio_ac97";
+				};
+			};
+
+			...
+
+			sd2_pmx: sd2@0 {
+				sd2 {
+					groups = "sd2_grp0";
+					function = "sd2";
+				};
+			};
+
+			...
+
+
+			sample0_cfg: sample0@0 {
+				sample0 {
+					pins = "ldd_0", "ldd_1";
+					bias-pull-up;
+				};
+			};
+
+			sample1_cfg: sample1@0 {
+				sample1 {
+					pins = "ldd_2", "ldd_3";
+					input-schmitt-enable;
+				};
+			};
+
+			sample2_cfg: sample2@0 {
+				sample2 {
+					groups = "uart4_nopause_grp";
+					bias-pull-down;
+				};
+			};
+
+			sample3_cfg: sample3@0 {
+				sample3 {
+					pins = "ldd_4", "ldd_5";
+					drive-strength = <2>;
+				};
+			};
+	};
+
+Please refer to pinctrl-bindings.txt in this directory for details of the common
+pinctrl bindings used by client devices.
+
+SiRFatlas7's pinmux nodes act as a container for an abitrary number of subnodes.
+Each of these subnodes represents some desired configuration for a group of pins.
+
+Required subnode-properties:
+- groups : An array of strings. Each string contains the name of a group.
+- function: A string containing the name of the function to mux to the
+  group.
+
+  Valid values for group and function names can be found from looking at the
+  group and function arrays in driver files:
+  drivers/pinctrl/pinctrl-sirf.c
+
+For example, pinctrl might have subnodes like the following:
+	sd0_pmx: sd0@0 {
+		sd0 {
+			groups = "sd0_grp";
+			function = "sd0";
+		};
+	};
+
+	sd1_pmx0: sd1@0 {
+		sd1 {
+			groups = "sd1_grp0";
+			function = "sd1_m0";
+		};
+	};
+
+	sd1_pmx1: sd1@1 {
+		sd1 {
+			groups = "sd1_grp1";
+			function = "sd1_m1";
+		};
+	};
+
+For a specific board, if it wants to use sd1,
+it can add the following to its board-specific .dts file.
+sd1: sd@0x12340000 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sd1_pmx0>;
+}
+
+or
+
+sd1: sd@0x12340000 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sd1_pmx1>;
+}