pinctrl: gpio: vt8500: Add pincontrol driver for arch-vt8500

This patch adds support for the GPIO/pinmux controller found on the VIA
VT8500 and Wondermedia WM8xxx-series SoCs.

Each pin within the controller is capable of operating as a GPIO or as
an alternate function. The pins are numbered according to their control
bank/bit so that if new pins are added, the existing numbering is maintained.

All currently supported SoCs are included: VT8500, WM8505, WM8650, WM8750 and
WM8850.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-vt8500.txt

+VIA VT8500 and Wondermedia WM8xxx-series pinmux/gpio controller
+
+These SoCs contain a combined Pinmux/GPIO module. Each pin may operate as
+either a GPIO in, GPIO out or as an alternate function (I2C, SPI etc).
+
+Required properties:
+- compatible: "via,vt8500-pinctrl", "wm,wm8505-pinctrl", "wm,wm8650-pinctrl",
+	"wm8750-pinctrl" or "wm,wm8850-pinctrl"
+- reg: Should contain the physical address of the module's registers.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Should be two.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells : Should be two. The first cell is the pin number and the
+  second cell is used to specify optional parameters.
+	bit 0 - active low
+
+Please refer to ../gpio/gpio.txt for a general description of GPIO bindings.
+
+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".
+
+Each pin configuration node lists the pin(s) to which it applies, and one or
+more of the mux functions to select on those pin(s), and pull-up/down
+configuration. Each subnode only affects those parameters that are explicitly
+listed. In other words, a subnode that lists only a mux function implies no
+information about any pull configuration. Similarly, a subnode that lists only
+a pull parameter implies no information about the mux function.
+
+Required subnode-properties:
+- wm,pins: An array of cells. Each cell contains the ID of a pin.
+
+Optional subnode-properties:
+- wm,function: Integer, containing the function to mux to the pin(s):
+  0: GPIO in
+  1: GPIO out
+  2: alternate
+
+- wm,pull: Integer, representing the pull-down/up to apply to the pin(s):
+  0: none
+  1: down
+  2: up
+
+Each of wm,function and wm,pull may contain either a single value which
+will be applied to all pins in wm,pins, or one value for each entry in
+wm,pins.
+
+Example:
+
+	pinctrl: pinctrl {
+		compatible = "wm,wm8505-pinctrl";
+		reg = <0xD8110000 0x10000>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		gpio-controller;
+		#gpio-cells = <2>;
+	};

arch/arm/mach-vt8500/Kconfig

@@ -7,6 +7,7 @@ config ARCH_VT8500
 	select GENERIC_CLOCKEVENTS
 	select HAVE_CLK
 	select VT8500_TIMER
+	select PINCTRL
 	help
 	  Support for VIA/WonderMedia VT8500/WM85xx System-on-Chip.
 

drivers/pinctrl/Kconfig

@@ -229,6 +229,7 @@ config PINCTRL_EXYNOS5440
 source "drivers/pinctrl/mvebu/Kconfig"
 source "drivers/pinctrl/sh-pfc/Kconfig"
 source "drivers/pinctrl/spear/Kconfig"
+source "drivers/pinctrl/vt8500/Kconfig"
 
 config PINCTRL_XWAY
 	bool

drivers/pinctrl/Makefile

@@ -52,3 +52,4 @@ obj-$(CONFIG_PLAT_ORION)        += mvebu/
 obj-$(CONFIG_ARCH_SHMOBILE)	+= sh-pfc/
 obj-$(CONFIG_SUPERH)		+= sh-pfc/
 obj-$(CONFIG_PLAT_SPEAR)	+= spear/
+obj-$(CONFIG_ARCH_VT8500)	+= vt8500/

drivers/pinctrl/vt8500/Kconfig

+#
+# VIA/Wondermedia PINCTRL drivers
+#
+
+if ARCH_VT8500
+
+config PINCTRL_WMT
+	bool
+	select PINMUX
+	select GENERIC_PINCONF
+
+config PINCTRL_VT8500
+	bool "VIA VT8500 pin controller driver"
+	depends on ARCH_WM8505
+	select PINCTRL_WMT
+	help
+	  Say yes here to support the gpio/pin control module on
+	  VIA VT8500 SoCs.
+
+config PINCTRL_WM8505
+	bool "Wondermedia WM8505 pin controller driver"
+	depends on ARCH_WM8505
+	select PINCTRL_WMT
+	help
+	  Say yes here to support the gpio/pin control module on
+	  Wondermedia WM8505 SoCs.
+
+config PINCTRL_WM8650
+	bool "Wondermedia WM8650 pin controller driver"
+	depends on ARCH_WM8505
+	select PINCTRL_WMT
+	help
+	  Say yes here to support the gpio/pin control module on
+	  Wondermedia WM8650 SoCs.
+
+config PINCTRL_WM8750
+	bool "Wondermedia WM8750 pin controller driver"
+	depends on ARCH_WM8750
+	select PINCTRL_WMT
+	help
+	  Say yes here to support the gpio/pin control module on
+	  Wondermedia WM8750 SoCs.
+
+config PINCTRL_WM8850
+	bool "Wondermedia WM8850 pin controller driver"
+	depends on ARCH_WM8850
+	select PINCTRL_WMT
+	help
+	  Say yes here to support the gpio/pin control module on
+	  Wondermedia WM8850 SoCs.
+
+endif

drivers/pinctrl/vt8500/Makefile

+# VIA/Wondermedia pinctrl support
+
+obj-$(CONFIG_PINCTRL_WMT)	+= pinctrl-wmt.o
+obj-$(CONFIG_PINCTRL_VT8500)	+= pinctrl-vt8500.o
+obj-$(CONFIG_PINCTRL_WM8505)	+= pinctrl-wm8505.o
+obj-$(CONFIG_PINCTRL_WM8650)	+= pinctrl-wm8650.o
+obj-$(CONFIG_PINCTRL_WM8750)	+= pinctrl-wm8750.o
+obj-$(CONFIG_PINCTRL_WM8850)	+= pinctrl-wm8850.o

drivers/pinctrl/vt8500/pinctrl-wmt.h

+/*
+ * Pinctrl driver for the Wondermedia SoC's
+ *
+ * Copyright (c) 2013 Tony Prisk <linux@prisktech.co.nz>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/gpio.h>
+
+/* VT8500 has no enable register in the extgpio bank. */
+#define NO_REG	0xFFFF
+
+#define WMT_PINCTRL_BANK(__en, __dir, __dout, __din, __pen, __pcfg)	\
+{									\
+	.reg_en		= __en,						\
+	.reg_dir	= __dir,					\
+	.reg_data_out	= __dout,					\
+	.reg_data_in	= __din,					\
+	.reg_pull_en	= __pen,					\
+	.reg_pull_cfg	= __pcfg,					\
+}
+
+/* Encode/decode the bank/bit pairs into a pin value */
+#define WMT_PIN(__bank, __offset)	((__bank << 5) | __offset)
+#define WMT_BANK_FROM_PIN(__pin)	(__pin >> 5)
+#define WMT_BIT_FROM_PIN(__pin)		(__pin & 0x1f)
+
+#define WMT_GROUP(__name, __data)		\
+{						\
+	.name = __name,				\
+	.pins = __data,				\
+	.npins = ARRAY_SIZE(__data),		\
+}
+
+struct wmt_pinctrl_bank_registers {
+	u32	reg_en;
+	u32	reg_dir;
+	u32	reg_data_out;
+	u32	reg_data_in;
+
+	u32	reg_pull_en;
+	u32	reg_pull_cfg;
+};
+
+struct wmt_pinctrl_group {
+	const char *name;
+	const unsigned int *pins;
+	const unsigned npins;
+};
+
+struct wmt_pinctrl_data {
+	struct device *dev;
+	struct pinctrl_dev *pctl_dev;
+
+	/* must be initialized before calling wmt_pinctrl_probe */
+	void __iomem *base;
+	const struct wmt_pinctrl_bank_registers *banks;
+	const struct pinctrl_pin_desc *pins;
+	const char * const *groups;
+
+	u32 nbanks;
+	u32 npins;
+	u32 ngroups;
+
+	struct gpio_chip gpio_chip;
+	struct pinctrl_gpio_range gpio_range;
+};
+
+int wmt_pinctrl_probe(struct platform_device *pdev,
+		      struct wmt_pinctrl_data *data);
+int wmt_pinctrl_remove(struct platform_device *pdev);