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>
diff --git a/drivers/pinctrl/vt8500/pinctrl-wmt.h b/drivers/pinctrl/vt8500/pinctrl-wmt.h
new file mode 100644
index 0000000..41f5f2d
--- /dev/null
+++ b/drivers/pinctrl/vt8500/pinctrl-wmt.h
@@ -0,0 +1,79 @@
+/*
+ * 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);