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>

drivers/pinctrl/meson/Makefile

@@ -0,0 +1,2 @@
+obj-y	+= pinctrl-meson8.o
+obj-y	+= pinctrl-meson.o

drivers/pinctrl/meson/pinctrl-meson.c

@@ -0,0 +1,761 @@
+/*
+ * 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/>.
+ */
+
+/*
+ * The available pins are organized in banks (A,B,C,D,E,X,Y,Z,AO,
+ * BOOT,CARD for meson6 and X,Y,DV,H,Z,AO,BOOT,CARD for meson8) and
+ * each bank has a variable number of pins.
+ *
+ * The AO bank is special because it belongs to the Always-On power
+ * domain which can't be powered off; the bank also uses a set of
+ * registers different from the other banks.
+ *
+ * For each of the two power domains (regular and always-on) there are
+ * 4 different register ranges that control the following properties
+ * of the pins:
+ *  1) pin muxing
+ *  2) pull enable/disable
+ *  3) pull up/down
+ *  4) GPIO direction, output value, input value
+ *
+ * In some cases the register ranges for pull enable and pull
+ * direction are the same and thus there are only 3 register ranges.
+ *
+ * Every pinmux group can be enabled by a specific bit in the first
+ * register range of the domain; when all groups for a given pin are
+ * disabled the pin acts as a GPIO.
+ *
+ * For the pull and GPIO configuration every bank uses a contiguous
+ * set of bits in the register sets described above; the same register
+ * can be shared by more banks with different offsets.
+ *
+ * In addition to this there are some registers shared between all
+ * banks that control the IRQ functionality. This feature is not
+ * supported at the moment by the driver.
+ */
+
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/seq_file.h>
+
+#include "../core.h"
+#include "../pinctrl-utils.h"
+#include "pinctrl-meson.h"
+
+/**
+ * meson_get_bank() - find the bank containing a given pin
+ *
+ * @domain:	the domain containing the pin
+ * @pin:	the pin number
+ * @bank:	the found bank
+ *
+ * Return:	0 on success, a negative value on error
+ */
+static int meson_get_bank(struct meson_domain *domain, unsigned int pin,
+			  struct meson_bank **bank)
+{
+	int i;
+
+	for (i = 0; i < domain->data->num_banks; i++) {
+		if (pin >= domain->data->banks[i].first &&
+		    pin <= domain->data->banks[i].last) {
+			*bank = &domain->data->banks[i];
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * meson_get_domain_and_bank() - find domain and bank containing a given pin
+ *
+ * @pc:		Meson pin controller device
+ * @pin:	the pin number
+ * @domain:	the found domain
+ * @bank:	the found bank
+ *
+ * Return:	0 on success, a negative value on error
+ */
+static int meson_get_domain_and_bank(struct meson_pinctrl *pc, unsigned int pin,
+				     struct meson_domain **domain,
+				     struct meson_bank **bank)
+{
+	struct meson_domain *d;
+	int i;
+
+	for (i = 0; i < pc->data->num_domains; i++) {
+		d = &pc->domains[i];
+		if (pin >= d->data->pin_base &&
+		    pin < d->data->pin_base + d->data->num_pins) {
+			*domain = d;
+			return meson_get_bank(d, pin, bank);
+		}
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * meson_calc_reg_and_bit() - calculate register and bit for a pin
+ *
+ * @bank:	the bank containing the pin
+ * @pin:	the pin number
+ * @reg_type:	the type of register needed (pull-enable, pull, etc...)
+ * @reg:	the computed register offset
+ * @bit:	the computed bit
+ */
+static void meson_calc_reg_and_bit(struct meson_bank *bank, unsigned int pin,
+				   enum meson_reg_type reg_type,
+				   unsigned int *reg, unsigned int *bit)
+{
+	struct meson_reg_desc *desc = &bank->regs[reg_type];
+
+	*reg = desc->reg * 4;
+	*bit = desc->bit + pin - bank->first;
+}
+
+static int meson_get_groups_count(struct pinctrl_dev *pcdev)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	return pc->data->num_groups;
+}
+
+static const char *meson_get_group_name(struct pinctrl_dev *pcdev,
+					unsigned selector)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	return pc->data->groups[selector].name;
+}
+
+static int meson_get_group_pins(struct pinctrl_dev *pcdev, unsigned selector,
+				const unsigned **pins, unsigned *num_pins)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	*pins = pc->data->groups[selector].pins;
+	*num_pins = pc->data->groups[selector].num_pins;
+
+	return 0;
+}
+
+static void meson_pin_dbg_show(struct pinctrl_dev *pcdev, struct seq_file *s,
+			       unsigned offset)
+{
+	seq_printf(s, " %s", dev_name(pcdev->dev));
+}
+
+static const struct pinctrl_ops meson_pctrl_ops = {
+	.get_groups_count	= meson_get_groups_count,
+	.get_group_name		= meson_get_group_name,
+	.get_group_pins		= meson_get_group_pins,
+	.dt_node_to_map		= pinconf_generic_dt_node_to_map_all,
+	.dt_free_map		= pinctrl_utils_dt_free_map,
+	.pin_dbg_show		= meson_pin_dbg_show,
+};
+
+/**
+ * meson_pmx_disable_other_groups() - disable other groups using a given pin
+ *
+ * @pc:		meson pin controller device
+ * @pin:	number of the pin
+ * @sel_group:	index of the selected group, or -1 if none
+ *
+ * The function disables all pinmux groups using a pin except the
+ * selected one. If @sel_group is -1 all groups are disabled, leaving
+ * the pin in GPIO mode.
+ */
+static void meson_pmx_disable_other_groups(struct meson_pinctrl *pc,
+					   unsigned int pin, int sel_group)
+{
+	struct meson_pmx_group *group;
+	struct meson_domain *domain;
+	int i, j;
+
+	for (i = 0; i < pc->data->num_groups; i++) {
+		group = &pc->data->groups[i];
+		if (group->is_gpio || i == sel_group)
+			continue;
+
+		for (j = 0; j < group->num_pins; j++) {
+			if (group->pins[j] == pin) {
+				/* We have found a group using the pin */
+				domain = &pc->domains[group->domain];
+				regmap_update_bits(domain->reg_mux,
+						   group->reg * 4,
+						   BIT(group->bit), 0);
+			}
+		}
+	}
+}
+
+static int meson_pmx_set_mux(struct pinctrl_dev *pcdev, unsigned func_num,
+			     unsigned group_num)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+	struct meson_pmx_func *func = &pc->data->funcs[func_num];
+	struct meson_pmx_group *group = &pc->data->groups[group_num];
+	struct meson_domain *domain = &pc->domains[group->domain];
+	int i, ret = 0;
+
+	dev_dbg(pc->dev, "enable function %s, group %s\n", func->name,
+		group->name);
+
+	/*
+	 * Disable groups using the same pin.
+	 * The selected group is not disabled to avoid glitches.
+	 */
+	for (i = 0; i < group->num_pins; i++)
+		meson_pmx_disable_other_groups(pc, group->pins[i], group_num);
+
+	/* Function 0 (GPIO) doesn't need any additional setting */
+	if (func_num)
+		ret = regmap_update_bits(domain->reg_mux, group->reg * 4,
+					 BIT(group->bit), BIT(group->bit));
+
+	return ret;
+}
+
+static int meson_pmx_request_gpio(struct pinctrl_dev *pcdev,
+				  struct pinctrl_gpio_range *range,
+				  unsigned offset)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	meson_pmx_disable_other_groups(pc, range->pin_base + offset, -1);
+
+	return 0;
+}
+
+static int meson_pmx_get_funcs_count(struct pinctrl_dev *pcdev)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	return pc->data->num_funcs;
+}
+
+static const char *meson_pmx_get_func_name(struct pinctrl_dev *pcdev,
+					   unsigned selector)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	return pc->data->funcs[selector].name;
+}
+
+static int meson_pmx_get_groups(struct pinctrl_dev *pcdev, unsigned selector,
+				const char * const **groups,
+				unsigned * const num_groups)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+
+	*groups = pc->data->funcs[selector].groups;
+	*num_groups = pc->data->funcs[selector].num_groups;
+
+	return 0;
+}
+
+static const struct pinmux_ops meson_pmx_ops = {
+	.set_mux = meson_pmx_set_mux,
+	.get_functions_count = meson_pmx_get_funcs_count,
+	.get_function_name = meson_pmx_get_func_name,
+	.get_function_groups = meson_pmx_get_groups,
+	.gpio_request_enable = meson_pmx_request_gpio,
+};
+
+static int meson_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
+			     unsigned long *configs, unsigned num_configs)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+	struct meson_domain *domain;
+	struct meson_bank *bank;
+	enum pin_config_param param;
+	unsigned int reg, bit;
+	int i, ret;
+	u16 arg;
+
+	ret = meson_get_domain_and_bank(pc, pin, &domain, &bank);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		arg = pinconf_to_config_argument(configs[i]);
+
+		switch (param) {
+		case PIN_CONFIG_BIAS_DISABLE:
+			dev_dbg(pc->dev, "pin %u: disable bias\n", pin);
+
+			meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+			ret = regmap_update_bits(domain->reg_pull, reg,
+						 BIT(bit), 0);
+			if (ret)
+				return ret;
+			break;
+		case PIN_CONFIG_BIAS_PULL_UP:
+			dev_dbg(pc->dev, "pin %u: enable pull-up\n", pin);
+
+			meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
+					       &reg, &bit);
+			ret = regmap_update_bits(domain->reg_pullen, reg,
+						 BIT(bit), BIT(bit));
+			if (ret)
+				return ret;
+
+			meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+			ret = regmap_update_bits(domain->reg_pull, reg,
+						 BIT(bit), BIT(bit));
+			if (ret)
+				return ret;
+			break;
+		case PIN_CONFIG_BIAS_PULL_DOWN:
+			dev_dbg(pc->dev, "pin %u: enable pull-down\n", pin);
+
+			meson_calc_reg_and_bit(bank, pin, REG_PULLEN,
+					       &reg, &bit);
+			ret = regmap_update_bits(domain->reg_pullen, reg,
+						 BIT(bit), BIT(bit));
+			if (ret)
+				return ret;
+
+			meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+			ret = regmap_update_bits(domain->reg_pull, reg,
+						 BIT(bit), 0);
+			if (ret)
+				return ret;
+			break;
+		default:
+			return -ENOTSUPP;
+		}
+	}
+
+	return 0;
+}
+
+static int meson_pinconf_get_pull(struct meson_pinctrl *pc, unsigned int pin)
+{
+	struct meson_domain *domain;
+	struct meson_bank *bank;
+	unsigned int reg, bit, val;
+	int ret, conf;
+
+	ret = meson_get_domain_and_bank(pc, pin, &domain, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_PULLEN, &reg, &bit);
+
+	ret = regmap_read(domain->reg_pullen, reg, &val);
+	if (ret)
+		return ret;
+
+	if (!(val & BIT(bit))) {
+		conf = PIN_CONFIG_BIAS_DISABLE;
+	} else {
+		meson_calc_reg_and_bit(bank, pin, REG_PULL, &reg, &bit);
+
+		ret = regmap_read(domain->reg_pull, reg, &val);
+		if (ret)
+			return ret;
+
+		if (val & BIT(bit))
+			conf = PIN_CONFIG_BIAS_PULL_UP;
+		else
+			conf = PIN_CONFIG_BIAS_PULL_DOWN;
+	}
+
+	return conf;
+}
+
+static int meson_pinconf_get(struct pinctrl_dev *pcdev, unsigned int pin,
+			     unsigned long *config)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+	enum pin_config_param param = pinconf_to_config_param(*config);
+	u16 arg;
+
+	switch (param) {
+	case PIN_CONFIG_BIAS_DISABLE:
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+	case PIN_CONFIG_BIAS_PULL_UP:
+		if (meson_pinconf_get_pull(pc, pin) == param)
+			arg = 1;
+		else
+			return -EINVAL;
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	*config = pinconf_to_config_packed(param, arg);
+	dev_dbg(pc->dev, "pinconf for pin %u is %lu\n", pin, *config);
+
+	return 0;
+}
+
+static int meson_pinconf_group_set(struct pinctrl_dev *pcdev,
+				   unsigned int num_group,
+				   unsigned long *configs, unsigned num_configs)
+{
+	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
+	struct meson_pmx_group *group = &pc->data->groups[num_group];
+	int i;
+
+	dev_dbg(pc->dev, "set pinconf for group %s\n", group->name);
+
+	for (i = 0; i < group->num_pins; i++) {
+		meson_pinconf_set(pcdev, group->pins[i], configs,
+				  num_configs);
+	}
+
+	return 0;
+}
+
+static int meson_pinconf_group_get(struct pinctrl_dev *pcdev,
+				   unsigned int group, unsigned long *config)
+{
+	return -ENOSYS;
+}
+
+static const struct pinconf_ops meson_pinconf_ops = {
+	.pin_config_get		= meson_pinconf_get,
+	.pin_config_set		= meson_pinconf_set,
+	.pin_config_group_get	= meson_pinconf_group_get,
+	.pin_config_group_set	= meson_pinconf_group_set,
+	.is_generic		= true,
+};
+
+static inline struct meson_domain *to_meson_domain(struct gpio_chip *chip)
+{
+	return container_of(chip, struct meson_domain, chip);
+}
+
+static int meson_gpio_request(struct gpio_chip *chip, unsigned gpio)
+{
+	return pinctrl_request_gpio(chip->base + gpio);
+}
+
+static void meson_gpio_free(struct gpio_chip *chip, unsigned gpio)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+
+	pinctrl_free_gpio(domain->data->pin_base + gpio);
+}
+
+static int meson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+	unsigned int reg, bit, pin;
+	struct meson_bank *bank;
+	int ret;
+
+	pin = domain->data->pin_base + gpio;
+	ret = meson_get_bank(domain, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_DIR, &reg, &bit);
+
+	return regmap_update_bits(domain->reg_gpio, reg, BIT(bit), BIT(bit));
+}
+
+static int meson_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
+				       int value)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+	unsigned int reg, bit, pin;
+	struct meson_bank *bank;
+	int ret;
+
+	pin = domain->data->pin_base + gpio;
+	ret = meson_get_bank(domain, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_DIR, &reg, &bit);
+	ret = regmap_update_bits(domain->reg_gpio, reg, BIT(bit), 0);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_OUT, &reg, &bit);
+	return regmap_update_bits(domain->reg_gpio, reg, BIT(bit),
+				  value ? BIT(bit) : 0);
+}
+
+static void meson_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+	unsigned int reg, bit, pin;
+	struct meson_bank *bank;
+	int ret;
+
+	pin = domain->data->pin_base + gpio;
+	ret = meson_get_bank(domain, pin, &bank);
+	if (ret)
+		return;
+
+	meson_calc_reg_and_bit(bank, pin, REG_OUT, &reg, &bit);
+	regmap_update_bits(domain->reg_gpio, reg, BIT(bit),
+			   value ? BIT(bit) : 0);
+}
+
+static int meson_gpio_get(struct gpio_chip *chip, unsigned gpio)
+{
+	struct meson_domain *domain = to_meson_domain(chip);
+	unsigned int reg, bit, val, pin;
+	struct meson_bank *bank;
+	int ret;
+
+	pin = domain->data->pin_base + gpio;
+	ret = meson_get_bank(domain, pin, &bank);
+	if (ret)
+		return ret;
+
+	meson_calc_reg_and_bit(bank, pin, REG_IN, &reg, &bit);
+	regmap_read(domain->reg_gpio, reg, &val);
+
+	return !!(val & BIT(bit));
+}
+
+static const struct of_device_id meson_pinctrl_dt_match[] = {
+	{
+		.compatible = "amlogic,meson8-pinctrl",
+		.data = &meson8_pinctrl_data,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, meson_pinctrl_dt_match);
+
+static int meson_gpiolib_register(struct meson_pinctrl *pc)
+{
+	struct meson_domain *domain;
+	int i, ret;
+
+	for (i = 0; i < pc->data->num_domains; i++) {
+		domain = &pc->domains[i];
+
+		domain->chip.label = domain->data->name;
+		domain->chip.dev = pc->dev;
+		domain->chip.request = meson_gpio_request;
+		domain->chip.free = meson_gpio_free;
+		domain->chip.direction_input = meson_gpio_direction_input;
+		domain->chip.direction_output = meson_gpio_direction_output;
+		domain->chip.get = meson_gpio_get;
+		domain->chip.set = meson_gpio_set;
+		domain->chip.base = -1;
+		domain->chip.ngpio = domain->data->num_pins;
+		domain->chip.can_sleep = false;
+		domain->chip.of_node = domain->of_node;
+		domain->chip.of_gpio_n_cells = 2;
+
+		ret = gpiochip_add(&domain->chip);
+		if (ret) {
+			dev_err(pc->dev, "can't add gpio chip %s\n",
+				domain->data->name);
+			goto fail;
+		}
+
+		ret = gpiochip_add_pin_range(&domain->chip, dev_name(pc->dev),
+					     0, domain->data->pin_base,
+					     domain->chip.ngpio);
+		if (ret) {
+			dev_err(pc->dev, "can't add pin range\n");
+			goto fail;
+		}
+	}
+
+	return 0;
+fail:
+	for (i--; i >= 0; i--)
+		gpiochip_remove(&pc->domains[i].chip);
+
+	return ret;
+}
+
+static struct meson_domain_data *meson_get_domain_data(struct meson_pinctrl *pc,
+						       struct device_node *np)
+{
+	int i;
+
+	for (i = 0; i < pc->data->num_domains; i++) {
+		if (!strcmp(np->name, pc->data->domain_data[i].name))
+			return &pc->data->domain_data[i];
+	}
+
+	return NULL;
+}
+
+static struct regmap_config meson_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static struct regmap *meson_map_resource(struct meson_pinctrl *pc,
+					 struct device_node *node, char *name)
+{
+	struct resource res;
+	void __iomem *base;
+	int i;
+
+	i = of_property_match_string(node, "reg-names", name);
+	if (of_address_to_resource(node, i, &res))
+		return ERR_PTR(-ENOENT);
+
+	base = devm_ioremap_resource(pc->dev, &res);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+
+	meson_regmap_config.max_register = resource_size(&res) - 4;
+	meson_regmap_config.name = devm_kasprintf(pc->dev, GFP_KERNEL,
+						  "%s-%s", node->name,
+						  name);
+	if (!meson_regmap_config.name)
+		return ERR_PTR(-ENOMEM);
+
+	return devm_regmap_init_mmio(pc->dev, base, &meson_regmap_config);
+}
+
+static int meson_pinctrl_parse_dt(struct meson_pinctrl *pc,
+				  struct device_node *node)
+{
+	struct device_node *np;
+	struct meson_domain *domain;
+	int i = 0, num_domains = 0;
+
+	for_each_child_of_node(node, np) {
+		if (!of_find_property(np, "gpio-controller", NULL))
+			continue;
+		num_domains++;
+	}
+
+	if (num_domains != pc->data->num_domains) {
+		dev_err(pc->dev, "wrong number of subnodes\n");
+		return -EINVAL;
+	}
+
+	pc->domains = devm_kzalloc(pc->dev, num_domains *
+				   sizeof(struct meson_domain), GFP_KERNEL);
+	if (!pc->domains)
+		return -ENOMEM;
+
+	for_each_child_of_node(node, np) {
+		if (!of_find_property(np, "gpio-controller", NULL))
+			continue;
+
+		domain = &pc->domains[i];
+
+		domain->data = meson_get_domain_data(pc, np);
+		if (!domain->data) {
+			dev_err(pc->dev, "domain data not found for node %s\n",
+				np->name);
+			return -ENODEV;
+		}
+
+		domain->of_node = np;
+
+		domain->reg_mux = meson_map_resource(pc, np, "mux");
+		if (IS_ERR(domain->reg_mux)) {
+			dev_err(pc->dev, "mux registers not found\n");
+			return PTR_ERR(domain->reg_mux);
+		}
+
+		domain->reg_pull = meson_map_resource(pc, np, "pull");
+		if (IS_ERR(domain->reg_pull)) {
+			dev_err(pc->dev, "pull registers not found\n");
+			return PTR_ERR(domain->reg_pull);
+		}
+
+		domain->reg_pullen = meson_map_resource(pc, np, "pull-enable");
+		/* Use pull region if pull-enable one is not present */
+		if (IS_ERR(domain->reg_pullen))
+			domain->reg_pullen = domain->reg_pull;
+
+		domain->reg_gpio = meson_map_resource(pc, np, "gpio");
+		if (IS_ERR(domain->reg_gpio)) {
+			dev_err(pc->dev, "gpio registers not found\n");
+			return PTR_ERR(domain->reg_gpio);
+		}
+
+		i++;
+	}
+
+	return 0;
+}
+
+static int meson_pinctrl_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct device *dev = &pdev->dev;
+	struct meson_pinctrl *pc;
+	int ret;
+
+	pc = devm_kzalloc(dev, sizeof(struct meson_pinctrl), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	pc->dev = dev;
+	match = of_match_node(meson_pinctrl_dt_match, pdev->dev.of_node);
+	pc->data = (struct meson_pinctrl_data *)match->data;
+
+	ret = meson_pinctrl_parse_dt(pc, pdev->dev.of_node);
+	if (ret)
+		return ret;
+
+	pc->desc.name		= "pinctrl-meson";
+	pc->desc.owner		= THIS_MODULE;
+	pc->desc.pctlops	= &meson_pctrl_ops;
+	pc->desc.pmxops		= &meson_pmx_ops;
+	pc->desc.confops	= &meson_pinconf_ops;
+	pc->desc.pins		= pc->data->pins;
+	pc->desc.npins		= pc->data->num_pins;
+
+	pc->pcdev = pinctrl_register(&pc->desc, pc->dev, pc);
+	if (!pc->pcdev) {
+		dev_err(pc->dev, "can't register pinctrl device");
+		return -EINVAL;
+	}
+
+	ret = meson_gpiolib_register(pc);
+	if (ret) {
+		pinctrl_unregister(pc->pcdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver meson_pinctrl_driver = {
+	.probe		= meson_pinctrl_probe,
+	.driver = {
+		.name	= "meson-pinctrl",
+		.of_match_table = meson_pinctrl_dt_match,
+	},
+};
+module_platform_driver(meson_pinctrl_driver);
+
+MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
+MODULE_DESCRIPTION("Amlogic Meson pinctrl driver");
+MODULE_LICENSE("GPL v2");

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;