pinctrl: add samsung pinctrl and gpiolib driver

Add a new device tree enabled pinctrl and gpiolib driver for Samsung
SoC's. This driver provides a common and extensible framework for all
Samsung SoC's to interface with the pinctrl and gpiolib subsystems. This
driver supports only device tree based instantiation and hence can be
used only on those Samsung platforms that have device tree enabled.

This driver is split into two parts: the pinctrl interface and the gpiolib
interface. The pinctrl interface registers pinctrl devices with the pinctrl
subsystem and gpiolib interface registers gpio chips with the gpiolib
subsystem. The information about the pins, pin groups, pin functions and
gpio chips, which are SoC specific, are parsed from device tree node.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

4 files changed, 1133 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 54e3588bef62..ffed467422e7 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -145,6 +145,11 @@ config PINCTRL_COH901
 	  COH 901 335 and COH 901 571/3. They contain 3, 5 or 7
 	  ports of 8 GPIO pins each.
 
+config PINCTRL_SAMSUNG
+	bool "Samsung pinctrl driver"
+	select PINMUX
+	select PINCONF
+
 source "drivers/pinctrl/spear/Kconfig"
 
 endmenu
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index f40b1f81ff2c..656ed83372cf 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -29,5 +29,6 @@ obj-$(CONFIG_PINCTRL_TEGRA20)	+= pinctrl-tegra20.o
 obj-$(CONFIG_PINCTRL_TEGRA30)	+= pinctrl-tegra30.o
 obj-$(CONFIG_PINCTRL_U300)	+= pinctrl-u300.o
 obj-$(CONFIG_PINCTRL_COH901)	+= pinctrl-coh901.o
+obj-$(CONFIG_PINCTRL_SAMSUNG)	+= pinctrl-samsung.o
 
 obj-$(CONFIG_PLAT_SPEAR)	+= spear/
diff --git a/drivers/pinctrl/pinctrl-samsung.c b/drivers/pinctrl/pinctrl-samsung.c
new file mode 100644
index 000000000000..8a24223d5334
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-samsung.c
@@ -0,0 +1,888 @@
+/*
+ * pin-controller/pin-mux/pin-config/gpio-driver for Samsung's SoC's.
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Copyright (c) 2012 Linaro Ltd
+ *		http://www.linaro.org
+ *
+ * Author: Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This driver implements the Samsung pinctrl driver. It supports setting up of
+ * pinmux and pinconf configurations. The gpiolib interface is also included.
+ * External interrupt (gpio and wakeup) support are not included in this driver
+ * but provides extensions to which platform specific implementation of the gpio
+ * and wakeup interrupts can be hooked to.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+
+#include "core.h"
+#include "pinctrl-samsung.h"
+
+#define GROUP_SUFFIX		"-grp"
+#define GSUFFIX_LEN		sizeof(GROUP_SUFFIX)
+#define FUNCTION_SUFFIX		"-mux"
+#define FSUFFIX_LEN		sizeof(FUNCTION_SUFFIX)
+
+/* list of all possible config options supported */
+struct pin_config {
+	char		*prop_cfg;
+	unsigned int	cfg_type;
+} pcfgs[] = {
+	{ "samsung,pin-pud", PINCFG_TYPE_PUD },
+	{ "samsung,pin-drv", PINCFG_TYPE_DRV },
+	{ "samsung,pin-con-pdn", PINCFG_TYPE_CON_PDN },
+	{ "samsung,pin-pud-pdn", PINCFG_TYPE_PUD_PDN },
+};
+
+/* check if the selector is a valid pin group selector */
+static int samsung_get_group_count(struct pinctrl_dev *pctldev)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	return drvdata->nr_groups;
+}
+
+/* return the name of the group selected by the group selector */
+static const char *samsung_get_group_name(struct pinctrl_dev *pctldev,
+						unsigned selector)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	return drvdata->pin_groups[selector].name;
+}
+
+/* return the pin numbers associated with the specified group */
+static int samsung_get_group_pins(struct pinctrl_dev *pctldev,
+		unsigned selector, const unsigned **pins, unsigned *num_pins)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	*pins = drvdata->pin_groups[selector].pins;
+	*num_pins = drvdata->pin_groups[selector].num_pins;
+	return 0;
+}
+
+/* create pinctrl_map entries by parsing device tree nodes */
+static int samsung_dt_node_to_map(struct pinctrl_dev *pctldev,
+			struct device_node *np, struct pinctrl_map **maps,
+			unsigned *nmaps)
+{
+	struct device *dev = pctldev->dev;
+	struct pinctrl_map *map;
+	unsigned long *cfg = NULL;
+	char *gname, *fname;
+	int cfg_cnt = 0, map_cnt = 0, idx = 0;
+
+	/* count the number of config options specfied in the node */
+	for (idx = 0; idx < ARRAY_SIZE(pcfgs); idx++) {
+		if (of_find_property(np, pcfgs[idx].prop_cfg, NULL))
+			cfg_cnt++;
+	}
+
+	/*
+	 * Find out the number of map entries to create. All the config options
+	 * can be accomadated into a single config map entry.
+	 */
+	if (cfg_cnt)
+		map_cnt = 1;
+	if (of_find_property(np, "samsung,pin-function", NULL))
+		map_cnt++;
+	if (!map_cnt) {
+		dev_err(dev, "node %s does not have either config or function "
+				"configurations\n", np->name);
+		return -EINVAL;
+	}
+
+	/* Allocate memory for pin-map entries */
+	map = kzalloc(sizeof(*map) * map_cnt, GFP_KERNEL);
+	if (!map) {
+		dev_err(dev, "could not alloc memory for pin-maps\n");
+		return -ENOMEM;
+	}
+	*nmaps = 0;
+
+	/*
+	 * Allocate memory for pin group name. The pin group name is derived
+	 * from the node name from which these map entries are be created.
+	 */
+	gname = kzalloc(strlen(np->name) + GSUFFIX_LEN, GFP_KERNEL);
+	if (!gname) {
+		dev_err(dev, "failed to alloc memory for group name\n");
+		goto free_map;
+	}
+	sprintf(gname, "%s%s", np->name, GROUP_SUFFIX);
+
+	/*
+	 * don't have config options? then skip over to creating function
+	 * map entries.
+	 */
+	if (!cfg_cnt)
+		goto skip_cfgs;
+
+	/* Allocate memory for config entries */
+	cfg = kzalloc(sizeof(*cfg) * cfg_cnt, GFP_KERNEL);
+	if (!cfg) {
+		dev_err(dev, "failed to alloc memory for configs\n");
+		goto free_gname;
+	}
+
+	/* Prepare a list of config settings */
+	for (idx = 0, cfg_cnt = 0; idx < ARRAY_SIZE(pcfgs); idx++) {
+		u32 value;
+		if (!of_property_read_u32(np, pcfgs[idx].prop_cfg, &value))
+			cfg[cfg_cnt++] =
+				PINCFG_PACK(pcfgs[idx].cfg_type, value);
+	}
+
+	/* create the config map entry */
+	map[*nmaps].data.configs.group_or_pin = gname;
+	map[*nmaps].data.configs.configs = cfg;
+	map[*nmaps].data.configs.num_configs = cfg_cnt;
+	map[*nmaps].type = PIN_MAP_TYPE_CONFIGS_GROUP;
+	*nmaps += 1;
+
+skip_cfgs:
+	/* create the function map entry */
+	if (of_find_property(np, "samsung,pin-function", NULL)) {
+		fname = kzalloc(strlen(np->name) + FSUFFIX_LEN,	GFP_KERNEL);
+		if (!fname) {
+			dev_err(dev, "failed to alloc memory for func name\n");
+			goto free_cfg;
+		}
+		sprintf(fname, "%s%s", np->name, FUNCTION_SUFFIX);
+
+		map[*nmaps].data.mux.group = gname;
+		map[*nmaps].data.mux.function = fname;
+		map[*nmaps].type = PIN_MAP_TYPE_MUX_GROUP;
+		*nmaps += 1;
+	}
+
+	*maps = map;
+	return 0;
+
+free_cfg:
+	kfree(cfg);
+free_gname:
+	kfree(gname);
+free_map:
+	kfree(map);
+	return -ENOMEM;
+}
+
+/* free the memory allocated to hold the pin-map table */
+static void samsung_dt_free_map(struct pinctrl_dev *pctldev,
+			     struct pinctrl_map *map, unsigned num_maps)
+{
+	int idx;
+
+	for (idx = 0; idx < num_maps; idx++) {
+		if (map[idx].type == PIN_MAP_TYPE_MUX_GROUP) {
+			kfree(map[idx].data.mux.function);
+			if (!idx)
+				kfree(map[idx].data.mux.group);
+		} else if (map->type == PIN_MAP_TYPE_CONFIGS_GROUP) {
+			kfree(map[idx].data.configs.configs);
+			if (!idx)
+				kfree(map[idx].data.configs.group_or_pin);
+		}
+	};
+
+	kfree(map);
+}
+
+/* list of pinctrl callbacks for the pinctrl core */
+static struct pinctrl_ops samsung_pctrl_ops = {
+	.get_groups_count	= samsung_get_group_count,
+	.get_group_name		= samsung_get_group_name,
+	.get_group_pins		= samsung_get_group_pins,
+	.dt_node_to_map		= samsung_dt_node_to_map,
+	.dt_free_map		= samsung_dt_free_map,
+};
+
+/* check if the selector is a valid pin function selector */
+static int samsung_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	return drvdata->nr_functions;
+}
+
+/* return the name of the pin function specified */
+static const char *samsung_pinmux_get_fname(struct pinctrl_dev *pctldev,
+						unsigned selector)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	return drvdata->pmx_functions[selector].name;
+}
+
+/* return the groups associated for the specified function selector */
+static int samsung_pinmux_get_groups(struct pinctrl_dev *pctldev,
+		unsigned selector, const char * const **groups,
+		unsigned * const num_groups)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	*groups = drvdata->pmx_functions[selector].groups;
+	*num_groups = drvdata->pmx_functions[selector].num_groups;
+	return 0;
+}
+
+/*
+ * given a pin number that is local to a pin controller, find out the pin bank
+ * and the register base of the pin bank.
+ */
+static void pin_to_reg_bank(struct gpio_chip *gc, unsigned pin,
+			void __iomem **reg, u32 *offset,
+			struct samsung_pin_bank **bank)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	struct samsung_pin_bank *b;
+
+	drvdata = dev_get_drvdata(gc->dev);
+	b = drvdata->ctrl->pin_banks;
+
+	while ((pin >= b->pin_base) &&
+			((b->pin_base + b->nr_pins - 1) < pin))
+		b++;
+
+	*reg = drvdata->virt_base + b->pctl_offset;
+	*offset = pin - b->pin_base;
+	if (bank)
+		*bank = b;
+
+	/* some banks have two config registers in a single bank */
+	if (*offset * b->func_width > BITS_PER_LONG)
+		*reg += 4;
+}
+
+/* enable or disable a pinmux function */
+static void samsung_pinmux_setup(struct pinctrl_dev *pctldev, unsigned selector,
+					unsigned group, bool enable)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	const unsigned int *pins;
+	struct samsung_pin_bank *bank;
+	void __iomem *reg;
+	u32 mask, shift, data, pin_offset, cnt;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	pins = drvdata->pin_groups[group].pins;
+
+	/*
+	 * for each pin in the pin group selected, program the correspoding pin
+	 * pin function number in the config register.
+	 */
+	for (cnt = 0; cnt < drvdata->pin_groups[group].num_pins; cnt++) {
+		pin_to_reg_bank(drvdata->gc, pins[cnt] - drvdata->ctrl->base,
+				&reg, &pin_offset, &bank);
+		mask = (1 << bank->func_width) - 1;
+		shift = pin_offset * bank->func_width;
+
+		data = readl(reg);
+		data &= ~(mask << shift);
+		if (enable)
+			data |= drvdata->pin_groups[group].func << shift;
+		writel(data, reg);
+	}
+}
+
+/* enable a specified pinmux by writing to registers */
+static int samsung_pinmux_enable(struct pinctrl_dev *pctldev, unsigned selector,
+					unsigned group)
+{
+	samsung_pinmux_setup(pctldev, selector, group, true);
+	return 0;
+}
+
+/* disable a specified pinmux by writing to registers */
+static void samsung_pinmux_disable(struct pinctrl_dev *pctldev,
+					unsigned selector, unsigned group)
+{
+	samsung_pinmux_setup(pctldev, selector, group, false);
+}
+
+/*
+ * The calls to gpio_direction_output() and gpio_direction_input()
+ * leads to this function call (via the pinctrl_gpio_direction_{input|output}()
+ * function called from the gpiolib interface).
+ */
+static int samsung_pinmux_gpio_set_direction(struct pinctrl_dev *pctldev,
+		struct pinctrl_gpio_range *range, unsigned offset, bool input)
+{
+	struct samsung_pin_bank *bank;
+	void __iomem *reg;
+	u32 data, pin_offset, mask, shift;
+
+	pin_to_reg_bank(range->gc, offset, &reg, &pin_offset, &bank);
+	mask = (1 << bank->func_width) - 1;
+	shift = pin_offset * bank->func_width;
+
+	data = readl(reg);
+	data &= ~(mask << shift);
+	if (!input)
+		data |= FUNC_OUTPUT << shift;
+	writel(data, reg);
+	return 0;
+}
+
+/* list of pinmux callbacks for the pinmux vertical in pinctrl core */
+static struct pinmux_ops samsung_pinmux_ops = {
+	.get_functions_count	= samsung_get_functions_count,
+	.get_function_name	= samsung_pinmux_get_fname,
+	.get_function_groups	= samsung_pinmux_get_groups,
+	.enable			= samsung_pinmux_enable,
+	.disable		= samsung_pinmux_disable,
+	.gpio_set_direction	= samsung_pinmux_gpio_set_direction,
+};
+
+/* set or get the pin config settings for a specified pin */
+static int samsung_pinconf_rw(struct pinctrl_dev *pctldev, unsigned int pin,
+				unsigned long *config, bool set)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	struct samsung_pin_bank *bank;
+	void __iomem *reg_base;
+	enum pincfg_type cfg_type = PINCFG_UNPACK_TYPE(*config);
+	u32 data, width, pin_offset, mask, shift;
+	u32 cfg_value, cfg_reg;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	pin_to_reg_bank(drvdata->gc, pin - drvdata->ctrl->base, &reg_base,
+					&pin_offset, &bank);
+
+	switch (cfg_type) {
+	case PINCFG_TYPE_PUD:
+		width = bank->pud_width;
+		cfg_reg = PUD_REG;
+		break;
+	case PINCFG_TYPE_DRV:
+		width = bank->drv_width;
+		cfg_reg = DRV_REG;
+		break;
+	case PINCFG_TYPE_CON_PDN:
+		width = bank->conpdn_width;
+		cfg_reg = CONPDN_REG;
+		break;
+	case PINCFG_TYPE_PUD_PDN:
+		width = bank->pudpdn_width;
+		cfg_reg = PUDPDN_REG;
+		break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	mask = (1 << width) - 1;
+	shift = pin_offset * width;
+	data = readl(reg_base + cfg_reg);
+
+	if (set) {
+		cfg_value = PINCFG_UNPACK_VALUE(*config);
+		data &= ~(mask << shift);
+		data |= (cfg_value << shift);
+		writel(data, reg_base + cfg_reg);
+	} else {
+		data >>= shift;
+		data &= mask;
+		*config = PINCFG_PACK(cfg_type, data);
+	}
+	return 0;
+}
+
+/* set the pin config settings for a specified pin */
+static int samsung_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
+				unsigned long config)
+{
+	return samsung_pinconf_rw(pctldev, pin, &config, true);
+}
+
+/* get the pin config settings for a specified pin */
+static int samsung_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
+					unsigned long *config)
+{
+	return samsung_pinconf_rw(pctldev, pin, config, false);
+}
+
+/* set the pin config settings for a specified pin group */
+static int samsung_pinconf_group_set(struct pinctrl_dev *pctldev,
+			unsigned group, unsigned long config)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	const unsigned int *pins;
+	unsigned int cnt;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	pins = drvdata->pin_groups[group].pins;
+
+	for (cnt = 0; cnt < drvdata->pin_groups[group].num_pins; cnt++)
+		samsung_pinconf_set(pctldev, pins[cnt], config);
+
+	return 0;
+}
+
+/* get the pin config settings for a specified pin group */
+static int samsung_pinconf_group_get(struct pinctrl_dev *pctldev,
+				unsigned int group, unsigned long *config)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	const unsigned int *pins;
+
+	drvdata = pinctrl_dev_get_drvdata(pctldev);
+	pins = drvdata->pin_groups[group].pins;
+	samsung_pinconf_get(pctldev, pins[0], config);
+	return 0;
+}
+
+/* list of pinconfig callbacks for pinconfig vertical in the pinctrl code */
+static struct pinconf_ops samsung_pinconf_ops = {
+	.pin_config_get		= samsung_pinconf_get,
+	.pin_config_set		= samsung_pinconf_set,
+	.pin_config_group_get	= samsung_pinconf_group_get,
+	.pin_config_group_set	= samsung_pinconf_group_set,
+};
+
+/* gpiolib gpio_set callback function */
+static void samsung_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+	void __iomem *reg;
+	u32 pin_offset, data;
+
+	pin_to_reg_bank(gc, offset, &reg, &pin_offset, NULL);
+	data = readl(reg + DAT_REG);
+	data &= ~(1 << pin_offset);
+	if (value)
+		data |= 1 << pin_offset;
+	writel(data, reg + DAT_REG);
+}
+
+/* gpiolib gpio_get callback function */
+static int samsung_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+	void __iomem *reg;
+	u32 pin_offset, data;
+
+	pin_to_reg_bank(gc, offset, &reg, &pin_offset, NULL);
+	data = readl(reg + DAT_REG);
+	data >>= pin_offset;
+	data &= 1;
+	return data;
+}
+
+/*
+ * gpiolib gpio_direction_input callback function. The setting of the pin
+ * mux function as 'gpio input' will be handled by the pinctrl susbsystem
+ * interface.
+ */
+static int samsung_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+	return pinctrl_gpio_direction_input(gc->base + offset);
+}
+
+/*
+ * gpiolib gpio_direction_output callback function. The setting of the pin
+ * mux function as 'gpio output' will be handled by the pinctrl susbsystem
+ * interface.
+ */
+static int samsung_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
+							int value)
+{
+	samsung_gpio_set(gc, offset, value);
+	return pinctrl_gpio_direction_output(gc->base + offset);
+}
+
+/*
+ * Parse the pin names listed in the 'samsung,pins' property and convert it
+ * into a list of gpio numbers are create a pin group from it.
+ */
+static int __init samsung_pinctrl_parse_dt_pins(struct platform_device *pdev,
+			struct device_node *cfg_np, struct pinctrl_desc *pctl,
+			unsigned int **pin_list, unsigned int *npins)
+{
+	struct device *dev = &pdev->dev;
+	struct property *prop;
+	struct pinctrl_pin_desc const *pdesc = pctl->pins;
+	unsigned int idx = 0, cnt;
+	const char *pin_name;
+
+	*npins = of_property_count_strings(cfg_np, "samsung,pins");
+	if (*npins < 0) {
+		dev_err(dev, "invalid pin list in %s node", cfg_np->name);
+		return -EINVAL;
+	}
+
+	*pin_list = devm_kzalloc(dev, *npins * sizeof(**pin_list), GFP_KERNEL);
+	if (!*pin_list) {
+		dev_err(dev, "failed to allocate memory for pin list\n");
+		return -ENOMEM;
+	}
+
+	of_property_for_each_string(cfg_np, "samsung,pins", prop, pin_name) {
+		for (cnt = 0; cnt < pctl->npins; cnt++) {
+			if (pdesc[cnt].name) {
+				if (!strcmp(pin_name, pdesc[cnt].name)) {
+					(*pin_list)[idx++] = pdesc[cnt].number;
+					break;
+				}
+			}
+		}
+		if (cnt == pctl->npins) {
+			dev_err(dev, "pin %s not valid in %s node\n",
+					pin_name, cfg_np->name);
+			devm_kfree(dev, *pin_list);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Parse the information about all the available pin groups and pin functions
+ * from device node of the pin-controller. A pin group is formed with all
+ * the pins listed in the "samsung,pins" property.
+ */
+static int __init samsung_pinctrl_parse_dt(struct platform_device *pdev,
+				struct samsung_pinctrl_drv_data *drvdata)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *dev_np = dev->of_node;
+	struct device_node *cfg_np;
+	struct samsung_pin_group *groups, *grp;
+	struct samsung_pmx_func *functions, *func;
+	unsigned *pin_list;
+	unsigned int npins, grp_cnt, func_idx = 0;
+	char *gname, *fname;
+	int ret;
+
+	grp_cnt = of_get_child_count(dev_np);
+	if (!grp_cnt)
+		return -EINVAL;
+
+	groups = devm_kzalloc(dev, grp_cnt * sizeof(*groups), GFP_KERNEL);
+	if (!groups) {
+		dev_err(dev, "failed allocate memory for ping group list\n");
+		return -EINVAL;
+	}
+	grp = groups;
+
+	functions = devm_kzalloc(dev, grp_cnt * sizeof(*functions), GFP_KERNEL);
+	if (!functions) {
+		dev_err(dev, "failed to allocate memory for function list\n");
+		return -EINVAL;
+	}
+	func = functions;
+
+	/*
+	 * Iterate over all the child nodes of the pin controller node
+	 * and create pin groups and pin function lists.
+	 */
+	for_each_child_of_node(dev_np, cfg_np) {
+		u32 function;
+		if (of_find_property(cfg_np, "interrupt-controller", NULL))
+			continue;
+
+		ret = samsung_pinctrl_parse_dt_pins(pdev, cfg_np,
+					&drvdata->pctl,	&pin_list, &npins);
+		if (ret)
+			return ret;
+
+		/* derive pin group name from the node name */
+		gname = devm_kzalloc(dev, strlen(cfg_np->name) + GSUFFIX_LEN,
+					GFP_KERNEL);
+		if (!gname) {
+			dev_err(dev, "failed to alloc memory for group name\n");
+			return -ENOMEM;
+		}
+		sprintf(gname, "%s%s", cfg_np->name, GROUP_SUFFIX);
+
+		grp->name = gname;
+		grp->pins = pin_list;
+		grp->num_pins = npins;
+		of_property_read_u32(cfg_np, "samsung,pin-function", &function);
+		grp->func = function;
+		grp++;
+
+		if (!of_find_property(cfg_np, "samsung,pin-function", NULL))
+			continue;
+
+		/* derive function name from the node name */
+		fname = devm_kzalloc(dev, strlen(cfg_np->name) + FSUFFIX_LEN,
+					GFP_KERNEL);
+		if (!fname) {
+			dev_err(dev, "failed to alloc memory for func name\n");
+			return -ENOMEM;
+		}
+		sprintf(fname, "%s%s", cfg_np->name, FUNCTION_SUFFIX);
+
+		func->name = fname;
+		func->groups = devm_kzalloc(dev, sizeof(char *), GFP_KERNEL);
+		if (!func->groups) {
+			dev_err(dev, "failed to alloc memory for group list "
+					"in pin function");
+			return -ENOMEM;
+		}
+		func->groups[0] = gname;
+		func->num_groups = 1;
+		func++;
+		func_idx++;
+	}
+
+	drvdata->pin_groups = groups;
+	drvdata->nr_groups = grp_cnt;
+	drvdata->pmx_functions = functions;
+	drvdata->nr_functions = func_idx;
+
+	return 0;
+}
+
+/* register the pinctrl interface with the pinctrl subsystem */
+static int __init samsung_pinctrl_register(struct platform_device *pdev,
+				struct samsung_pinctrl_drv_data *drvdata)
+{
+	struct pinctrl_desc *ctrldesc = &drvdata->pctl;
+	struct pinctrl_pin_desc *pindesc, *pdesc;
+	struct samsung_pin_bank *pin_bank;
+	char *pin_names;
+	int pin, bank, ret;
+
+	ctrldesc->name = "samsung-pinctrl";
+	ctrldesc->owner = THIS_MODULE;
+	ctrldesc->pctlops = &samsung_pctrl_ops;
+	ctrldesc->pmxops = &samsung_pinmux_ops;
+	ctrldesc->confops = &samsung_pinconf_ops;
+
+	pindesc = devm_kzalloc(&pdev->dev, sizeof(*pindesc) *
+			drvdata->ctrl->nr_pins, GFP_KERNEL);
+	if (!pindesc) {
+		dev_err(&pdev->dev, "mem alloc for pin descriptors failed\n");
+		return -ENOMEM;
+	}
+	ctrldesc->pins = pindesc;
+	ctrldesc->npins = drvdata->ctrl->nr_pins;
+	ctrldesc->npins = drvdata->ctrl->nr_pins;
+
+	/* dynamically populate the pin number and pin name for pindesc */
+	for (pin = 0, pdesc = pindesc; pin < ctrldesc->npins; pin++, pdesc++)
+		pdesc->number = pin + drvdata->ctrl->base;
+
+	/*
+	 * allocate space for storing the dynamically generated names for all
+	 * the pins which belong to this pin-controller.
+	 */
+	pin_names = devm_kzalloc(&pdev->dev, sizeof(char) * PIN_NAME_LENGTH *
+					drvdata->ctrl->nr_pins, GFP_KERNEL);
+	if (!pin_names) {
+		dev_err(&pdev->dev, "mem alloc for pin names failed\n");
+		return -ENOMEM;
+	}
+
+	/* for each pin, the name of the pin is pin-bank name + pin number */
+	for (bank = 0; bank < drvdata->ctrl->nr_banks; bank++) {
+		pin_bank = &drvdata->ctrl->pin_banks[bank];
+		for (pin = 0; pin < pin_bank->nr_pins; pin++) {
+			sprintf(pin_names, "%s-%d", pin_bank->name, pin);
+			pdesc = pindesc + pin_bank->pin_base + pin;
+			pdesc->name = pin_names;
+			pin_names += PIN_NAME_LENGTH;
+		}
+	}
+
+	drvdata->pctl_dev = pinctrl_register(ctrldesc, &pdev->dev, drvdata);
+	if (!drvdata->pctl_dev) {
+		dev_err(&pdev->dev, "could not register pinctrl driver\n");
+		return -EINVAL;
+	}
+
+	drvdata->grange.name = "samsung-pctrl-gpio-range";
+	drvdata->grange.id = 0;
+	drvdata->grange.base = drvdata->ctrl->base;
+	drvdata->grange.npins = drvdata->ctrl->nr_pins;
+	drvdata->grange.gc = drvdata->gc;
+	pinctrl_add_gpio_range(drvdata->pctl_dev, &drvdata->grange);
+
+	ret = samsung_pinctrl_parse_dt(pdev, drvdata);
+	if (ret) {
+		pinctrl_unregister(drvdata->pctl_dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+/* register the gpiolib interface with the gpiolib subsystem */
+static int __init samsung_gpiolib_register(struct platform_device *pdev,
+				struct samsung_pinctrl_drv_data *drvdata)
+{
+	struct gpio_chip *gc;
+	int ret;
+
+	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
+	if (!gc) {
+		dev_err(&pdev->dev, "mem alloc for gpio_chip failed\n");
+		return -ENOMEM;
+	}
+
+	drvdata->gc = gc;
+	gc->base = drvdata->ctrl->base;
+	gc->ngpio = drvdata->ctrl->nr_pins;
+	gc->dev = &pdev->dev;
+	gc->set = samsung_gpio_set;
+	gc->get = samsung_gpio_get;
+	gc->direction_input = samsung_gpio_direction_input;
+	gc->direction_output = samsung_gpio_direction_output;
+	gc->label = drvdata->ctrl->label;
+	gc->owner = THIS_MODULE;
+	ret = gpiochip_add(gc);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register gpio_chip %s, error "
+					"code: %d\n", gc->label, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/* unregister the gpiolib interface with the gpiolib subsystem */
+static int __init samsung_gpiolib_unregister(struct platform_device *pdev,
+				struct samsung_pinctrl_drv_data *drvdata)
+{
+	int ret = gpiochip_remove(drvdata->gc);
+	if (ret) {
+		dev_err(&pdev->dev, "gpio chip remove failed\n");
+		return ret;
+	}
+	return 0;
+}
+
+static const struct of_device_id samsung_pinctrl_dt_match[];
+
+/* retrieve the soc specific data */
+static inline struct samsung_pin_ctrl *samsung_pinctrl_get_soc_data(
+				struct platform_device *pdev)
+{
+	int id;
+	const struct of_device_id *match;
+	const struct device_node *node = pdev->dev.of_node;
+
+	id = of_alias_get_id(pdev->dev.of_node, "pinctrl");
+	if (id < 0) {
+		dev_err(&pdev->dev, "failed to get alias id\n");
+		return NULL;
+	}
+	match = of_match_node(samsung_pinctrl_dt_match, node);
+	return (struct samsung_pin_ctrl *)match->data + id;
+}
+
+static int __devinit samsung_pinctrl_probe(struct platform_device *pdev)
+{
+	struct samsung_pinctrl_drv_data *drvdata;
+	struct device *dev = &pdev->dev;
+	struct samsung_pin_ctrl *ctrl;
+	struct resource *res;
+	int ret;
+
+	if (!dev->of_node) {
+		dev_err(dev, "device tree node not found\n");
+		return -ENODEV;
+	}
+
+	ctrl = samsung_pinctrl_get_soc_data(pdev);
+	if (!ctrl) {
+		dev_err(&pdev->dev, "driver data not available\n");
+		return -EINVAL;
+	}
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata) {
+		dev_err(dev, "failed to allocate memory for driver's "
+				"private data\n");
+		return -ENOMEM;
+	}
+	drvdata->ctrl = ctrl;
+	drvdata->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "cannot find IO resource\n");
+		return -ENOENT;
+	}
+
+	drvdata->virt_base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!drvdata->virt_base) {
+		dev_err(dev, "ioremap failed\n");
+		return -ENODEV;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (res)
+		drvdata->irq = res->start;
+
+	ret = samsung_gpiolib_register(pdev, drvdata);
+	if (ret)
+		return ret;
+
+	ret = samsung_pinctrl_register(pdev, drvdata);
+	if (ret) {
+		samsung_gpiolib_unregister(pdev, drvdata);
+		return ret;
+	}
+
+	if (ctrl->eint_gpio_init)
+		ctrl->eint_gpio_init(drvdata);
+	if (ctrl->eint_wkup_init)
+		ctrl->eint_wkup_init(drvdata);
+
+	platform_set_drvdata(pdev, drvdata);
+	return 0;
+}
+
+static const struct of_device_id samsung_pinctrl_dt_match[] = {
+	{ .compatible = "samsung,pinctrl-exynos4210",
+		.data = (void *)exynos4210_pin_ctrl },
+	{},
+};
+MODULE_DEVICE_TABLE(of, samsung_pinctrl_dt_match);
+
+static struct platform_driver samsung_pinctrl_driver = {
+	.probe		= samsung_pinctrl_probe,
+	.driver = {
+		.name	= "samsung-pinctrl",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(samsung_pinctrl_dt_match),
+	},
+};
+
+static int __init samsung_pinctrl_drv_register(void)
+{
+	return platform_driver_register(&samsung_pinctrl_driver);
+}
+postcore_initcall(samsung_pinctrl_drv_register);
+
+static void __exit samsung_pinctrl_drv_unregister(void)
+{
+	platform_driver_unregister(&samsung_pinctrl_driver);
+}
+module_exit(samsung_pinctrl_drv_unregister);
+
+MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com>");
+MODULE_DESCRIPTION("Samsung pinctrl driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/pinctrl/pinctrl-samsung.h b/drivers/pinctrl/pinctrl-samsung.h
new file mode 100644
index 000000000000..b8956934cda6
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-samsung.h
@@ -0,0 +1,239 @@
+/*
+ * pin-controller/pin-mux/pin-config/gpio-driver for Samsung's SoC's.
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Copyright (c) 2012 Linaro Ltd
+ *		http://www.linaro.org
+ *
+ * Author: Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __PINCTRL_SAMSUNG_H
+#define __PINCTRL_SAMSUNG_H
+
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/machine.h>
+
+/* register offsets within a pin bank */
+#define DAT_REG		0x4
+#define PUD_REG		0x8
+#define DRV_REG		0xC
+#define CONPDN_REG	0x10
+#define PUDPDN_REG	0x14
+
+/* pinmux function number for pin as gpio output line */
+#define FUNC_OUTPUT	0x1
+
+/**
+ * enum pincfg_type - possible pin configuration types supported.
+ * @PINCFG_TYPE_PUD: Pull up/down configuration.
+ * @PINCFG_TYPE_DRV: Drive strength configuration.
+ * @PINCFG_TYPE_CON_PDN: Pin function in power down mode.
+ * @PINCFG_TYPE_PUD_PDN: Pull up/down configuration in power down mode.
+ */
+enum pincfg_type {
+	PINCFG_TYPE_PUD,
+	PINCFG_TYPE_DRV,
+	PINCFG_TYPE_CON_PDN,
+	PINCFG_TYPE_PUD_PDN,
+};
+
+/*
+ * pin configuration (pull up/down and drive strength) type and its value are
+ * packed together into a 16-bits. The upper 8-bits represent the configuration
+ * type and the lower 8-bits hold the value of the configuration type.
+ */
+#define PINCFG_TYPE_MASK		0xFF
+#define PINCFG_VALUE_SHIFT		8
+#define PINCFG_VALUE_MASK		(0xFF << PINCFG_VALUE_SHIFT)
+#define PINCFG_PACK(type, value)	(((value) << PINCFG_VALUE_SHIFT) | type)
+#define PINCFG_UNPACK_TYPE(cfg)		((cfg) & PINCFG_TYPE_MASK)
+#define PINCFG_UNPACK_VALUE(cfg)	(((cfg) & PINCFG_VALUE_MASK) >> \
+						PINCFG_VALUE_SHIFT)
+/**
+ * enum eint_type - possible external interrupt types.
+ * @EINT_TYPE_NONE: bank does not support external interrupts
+ * @EINT_TYPE_GPIO: bank supportes external gpio interrupts
+ * @EINT_TYPE_WKUP: bank supportes external wakeup interrupts
+ *
+ * Samsung GPIO controller groups all the available pins into banks. The pins
+ * in a pin bank can support external gpio interrupts or external wakeup
+ * interrupts or no interrupts at all. From a software perspective, the only
+ * difference between external gpio and external wakeup interrupts is that
+ * the wakeup interrupts can additionally wakeup the system if it is in
+ * suspended state.
+ */
+enum eint_type {
+	EINT_TYPE_NONE,
+	EINT_TYPE_GPIO,
+	EINT_TYPE_WKUP,
+};
+
+/* maximum length of a pin in pin descriptor (example: "gpa0-0") */
+#define PIN_NAME_LENGTH	10
+
+#define PIN_GROUP(n, p, f)				\
+	{						\
+		.name		= n,			\
+		.pins		= p,			\
+		.num_pins	= ARRAY_SIZE(p),	\
+		.func		= f			\
+	}
+
+#define PMX_FUNC(n, g)					\
+	{						\
+		.name		= n,			\
+		.groups		= g,			\
+		.num_groups	= ARRAY_SIZE(g),	\
+	}
+
+struct samsung_pinctrl_drv_data;
+
+/**
+ * struct samsung_pin_bank: represent a controller pin-bank.
+ * @reg_offset: starting offset of the pin-bank registers.
+ * @pin_base: starting pin number of the bank.
+ * @nr_pins: number of pins included in this bank.
+ * @func_width: width of the function selector bit field.
+ * @pud_width: width of the pin pull up/down selector bit field.
+ * @drv_width: width of the pin driver strength selector bit field.
+ * @conpdn_width: width of the sleep mode function selector bin field.
+ * @pudpdn_width: width of the sleep mode pull up/down selector bit field.
+ * @eint_type: type of the external interrupt supported by the bank.
+ * @irq_base: starting controller local irq number of the bank.
+ * @name: name to be prefixed for each pin in this pin bank.
+ */
+struct samsung_pin_bank {
+	u32		pctl_offset;
+	u32		pin_base;
+	u8		nr_pins;
+	u8		func_width;
+	u8		pud_width;
+	u8		drv_width;
+	u8		conpdn_width;
+	u8		pudpdn_width;
+	enum eint_type	eint_type;
+	u32		irq_base;
+	char		*name;
+};
+
+/**
+ * struct samsung_pin_ctrl: represent a pin controller.
+ * @pin_banks: list of pin banks included in this controller.
+ * @nr_banks: number of pin banks.
+ * @base: starting system wide pin number.
+ * @nr_pins: number of pins supported by the controller.
+ * @nr_gint: number of external gpio interrupts supported.
+ * @nr_wint: number of external wakeup interrupts supported.
+ * @geint_con: offset of the ext-gpio controller registers.
+ * @geint_mask: offset of the ext-gpio interrupt mask registers.
+ * @geint_pend: offset of the ext-gpio interrupt pending registers.
+ * @weint_con: offset of the ext-wakeup controller registers.
+ * @weint_mask: offset of the ext-wakeup interrupt mask registers.
+ * @weint_pend: offset of the ext-wakeup interrupt pending registers.
+ * @svc: offset of the interrupt service register.
+ * @eint_gpio_init: platform specific callback to setup the external gpio
+ *	interrupts for the controller.
+ * @eint_wkup_init: platform specific callback to setup the external wakeup
+ *	interrupts for the controller.
+ * @label: for debug information.
+ */
+struct samsung_pin_ctrl {
+	struct samsung_pin_bank	*pin_banks;
+	u32		nr_banks;
+
+	u32		base;
+	u32		nr_pins;
+	u32		nr_gint;
+	u32		nr_wint;
+
+	u32		geint_con;
+	u32		geint_mask;
+	u32		geint_pend;
+
+	u32		weint_con;
+	u32		weint_mask;
+	u32		weint_pend;
+
+	u32		svc;
+
+	int		(*eint_gpio_init)(struct samsung_pinctrl_drv_data *);
+	int		(*eint_wkup_init)(struct samsung_pinctrl_drv_data *);
+	char		*label;
+};
+
+/**
+ * struct samsung_pinctrl_drv_data: wrapper for holding driver data together.
+ * @virt_base: register base address of the controller.
+ * @dev: device instance representing the controller.
+ * @irq: interrpt number used by the controller to notify gpio interrupts.
+ * @ctrl: pin controller instance managed by the driver.
+ * @pctl: pin controller descriptor registered with the pinctrl subsystem.
+ * @pctl_dev: cookie representing pinctrl device instance.
+ * @pin_groups: list of pin groups available to the driver.
+ * @nr_groups: number of such pin groups.
+ * @pmx_functions: list of pin functions available to the driver.
+ * @nr_function: number of such pin functions.
+ * @gc: gpio_chip instance registered with gpiolib.
+ * @grange: linux gpio pin range supported by this controller.
+ */
+struct samsung_pinctrl_drv_data {
+	void __iomem			*virt_base;
+	struct device			*dev;
+	int				irq;
+
+	struct samsung_pin_ctrl		*ctrl;
+	struct pinctrl_desc		pctl;
+	struct pinctrl_dev		*pctl_dev;
+
+	const struct samsung_pin_group	*pin_groups;
+	unsigned int			nr_groups;
+	const struct samsung_pmx_func	*pmx_functions;
+	unsigned int			nr_functions;
+
+	struct irq_domain		*gpio_irqd;
+	struct irq_domain		*wkup_irqd;
+
+	struct gpio_chip		*gc;
+	struct pinctrl_gpio_range	grange;
+};
+
+/**
+ * struct samsung_pin_group: represent group of pins of a pinmux function.
+ * @name: name of the pin group, used to lookup the group.
+ * @pins: the pins included in this group.
+ * @num_pins: number of pins included in this group.
+ * @func: the function number to be programmed when selected.
+ */
+struct samsung_pin_group {
+	const char		*name;
+	const unsigned int	*pins;
+	u8			num_pins;
+	u8			func;
+};
+
+/**
+ * struct samsung_pmx_func: represent a pin function.
+ * @name: name of the pin function, used to lookup the function.
+ * @groups: one or more names of pin groups that provide this function.
+ * @num_groups: number of groups included in @groups.
+ */
+struct samsung_pmx_func {
+	const char		*name;
+	const char		**groups;
+	u8			num_groups;
+};
+
+/* list of all exported SoC specific data */
+extern struct samsung_pin_ctrl exynos4210_pin_ctrl[];
+
+#endif /* __PINCTRL_SAMSUNG_H */