pinctrl: add driver for Amlogic Meson SoCs

This is a driver for the pinmux and GPIO controller available in
Amlogic Meson SoCs. It currently supports only Meson8, however the
common code should be generic enough to work also for other SoCs after
having defined the proper set of functions and groups.

GPIO interrupts are not supported at the moment due to lack of
documentation.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 209 insertions, 0 deletions

diff --git a/drivers/pinctrl/meson/pinctrl-meson.h b/drivers/pinctrl/meson/pinctrl-meson.h
new file mode 100644
index 000000000000..bfea8adc7953
--- /dev/null
+++ b/drivers/pinctrl/meson/pinctrl-meson.h
@@ -0,0 +1,209 @@
+/*
+ * Pin controller and GPIO driver for Amlogic Meson SoCs
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/gpio.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+/**
+ * struct meson_pmx_group - a pinmux group
+ *
+ * @name:	group name
+ * @pins:	pins in the group
+ * @num_pins:	number of pins in the group
+ * @is_gpio:	whether the group is a single GPIO group
+ * @reg:	register offset for the group in the domain mux registers
+ * @bit		bit index enabling the group
+ * @domain:	index of the domain this group belongs to
+ */
+struct meson_pmx_group {
+	const char *name;
+	const unsigned int *pins;
+	unsigned int num_pins;
+	bool is_gpio;
+	unsigned int reg;
+	unsigned int bit;
+	unsigned int domain;
+};
+
+/**
+ * struct meson_pmx_func - a pinmux function
+ *
+ * @name:	function name
+ * @groups:	groups in the function
+ * @num_groups:	number of groups in the function
+ */
+struct meson_pmx_func {
+	const char *name;
+	const char * const *groups;
+	unsigned int num_groups;
+};
+
+/**
+ * struct meson_reg_desc - a register descriptor
+ *
+ * @reg:	register offset in the regmap
+ * @bit:	bit index in register
+ *
+ * The structure describes the information needed to control pull,
+ * pull-enable, direction, etc. for a single pin
+ */
+struct meson_reg_desc {
+	unsigned int reg;
+	unsigned int bit;
+};
+
+/**
+ * enum meson_reg_type - type of registers encoded in @meson_reg_desc
+ */
+enum meson_reg_type {
+	REG_PULLEN,
+	REG_PULL,
+	REG_DIR,
+	REG_OUT,
+	REG_IN,
+	NUM_REG,
+};
+
+/**
+ * struct meson bank
+ *
+ * @name:	bank name
+ * @first:	first pin of the bank
+ * @last:	last pin of the bank
+ * @regs:	array of register descriptors
+ *
+ * A bank represents a set of pins controlled by a contiguous set of
+ * bits in the domain registers. The structure specifies which bits in
+ * the regmap control the different functionalities. Each member of
+ * the @regs array refers to the first pin of the bank.
+ */
+struct meson_bank {
+	const char *name;
+	unsigned int first;
+	unsigned int last;
+	struct meson_reg_desc regs[NUM_REG];
+};
+
+/**
+ * struct meson_domain_data - domain platform data
+ *
+ * @name:	name of the domain
+ * @banks:	set of banks belonging to the domain
+ * @num_banks:	number of banks in the domain
+ */
+struct meson_domain_data {
+	const char *name;
+	struct meson_bank *banks;
+	unsigned int num_banks;
+	unsigned int pin_base;
+	unsigned int num_pins;
+};
+
+/**
+ * struct meson_domain
+ *
+ * @reg_mux:	registers for mux settings
+ * @reg_pullen:	registers for pull-enable settings
+ * @reg_pull:	registers for pull settings
+ * @reg_gpio:	registers for gpio settings
+ * @chip:	gpio chip associated with the domain
+ * @data;	platform data for the domain
+ * @node:	device tree node for the domain
+ *
+ * A domain represents a set of banks controlled by the same set of
+ * registers.
+ */
+struct meson_domain {
+	struct regmap *reg_mux;
+	struct regmap *reg_pullen;
+	struct regmap *reg_pull;
+	struct regmap *reg_gpio;
+
+	struct gpio_chip chip;
+	struct meson_domain_data *data;
+	struct device_node *of_node;
+};
+
+struct meson_pinctrl_data {
+	const struct pinctrl_pin_desc *pins;
+	struct meson_pmx_group *groups;
+	struct meson_pmx_func *funcs;
+	struct meson_domain_data *domain_data;
+	unsigned int num_pins;
+	unsigned int num_groups;
+	unsigned int num_funcs;
+	unsigned int num_domains;
+};
+
+struct meson_pinctrl {
+	struct device *dev;
+	struct pinctrl_dev *pcdev;
+	struct pinctrl_desc desc;
+	struct meson_pinctrl_data *data;
+	struct meson_domain *domains;
+};
+
+#define GROUP(grp, r, b)						\
+	{								\
+		.name = #grp,						\
+		.pins = grp ## _pins,					\
+		.num_pins = ARRAY_SIZE(grp ## _pins),			\
+		.reg = r,						\
+		.bit = b,						\
+		.domain = 0,						\
+	 }
+
+#define GPIO_GROUP(gpio)						\
+	{								\
+		.name = #gpio,						\
+		.pins = (const unsigned int[]){ PIN_ ## gpio},		\
+		.num_pins = 1,						\
+		.is_gpio = true,					\
+	 }
+
+#define GROUP_AO(grp, r, b)						\
+	{								\
+		.name = #grp,						\
+		.pins = grp ## _pins,					\
+		.num_pins = ARRAY_SIZE(grp ## _pins),			\
+		.reg = r,						\
+		.bit = b,						\
+		.domain = 1,						\
+	 }
+
+#define FUNCTION(fn)							\
+	{								\
+		.name = #fn,						\
+		.groups = fn ## _groups,				\
+		.num_groups = ARRAY_SIZE(fn ## _groups),		\
+	}
+
+#define BANK(n, f, l, per, peb, pr, pb, dr, db, or, ob, ir, ib)		\
+	{								\
+		.name	= n,						\
+		.first	= f,						\
+		.last	= l,						\
+		.regs	= {						\
+			[REG_PULLEN]	= { per, peb },			\
+			[REG_PULL]	= { pr, pb },			\
+			[REG_DIR]	= { dr, db },			\
+			[REG_OUT]	= { or, ob },			\
+			[REG_IN]	= { ir, ib },			\
+		},							\
+	 }
+
+#define MESON_PIN(x) PINCTRL_PIN(PIN_ ## x, #x)
+
+extern struct meson_pinctrl_data meson8_pinctrl_data;