[PATCH v2 11/18] pinctrl: Add pinctrl driver for STM32 MCUs

[Maxime Coquelin]

This driver adds pinctrl and GPIO support to STMicrolectronic's
STM32 family of MCUs.

Pin muxing and GPIO handling have been tested on STM32F429
based Discovery board.

Signed-off-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
---
 drivers/pinctrl/Kconfig                     |  10 +
 drivers/pinctrl/Makefile                    |   1 +
 drivers/pinctrl/pinctrl-stm32.c             | 779 ++++++++++++++++++++++++++++
 include/dt-bindings/pinctrl/pinctrl-stm32.h |  43 ++
 4 files changed, 833 insertions(+)
 create mode 100644 drivers/pinctrl/pinctrl-stm32.c
 create mode 100644 include/dt-bindings/pinctrl/pinctrl-stm32.h

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index d014f22..84cd081 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -125,6 +125,16 @@ config PINCTRL_ST
 	select PINCONF
 	select GPIOLIB_IRQCHIP
 
+config PINCTRL_STM32
+	bool "STMicroelectronics STM32 pinctrl driver"
+	depends on OF
+	depends on ARCH_STM32 || COMPILE_TEST
+	select PINMUX
+	select PINCONF
+	select GPIOLIB_IRQCHIP
+	help
+	  This selects the device tree based generic pinctrl driver for STM32.
+
 config PINCTRL_TEGRA
 	bool
 	select PINMUX
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index c030b3d..06ef8ab 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_PINCTRL_XWAY)	+= pinctrl-xway.o
 obj-$(CONFIG_PINCTRL_LANTIQ)	+= pinctrl-lantiq.o
 obj-$(CONFIG_PINCTRL_TB10X)	+= pinctrl-tb10x.o
 obj-$(CONFIG_PINCTRL_ST) 	+= pinctrl-st.o
+obj-$(CONFIG_PINCTRL_STM32) 	+= pinctrl-stm32.o
 
 obj-$(CONFIG_ARCH_BERLIN)	+= berlin/
 obj-y				+= freescale/
diff --git a/drivers/pinctrl/pinctrl-stm32.c b/drivers/pinctrl/pinctrl-stm32.c
new file mode 100644
index 0000000..5c474b0
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-stm32.c
@@ -0,0 +1,779 @@
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Author:  Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Heavily based on pinctrl-st.c from Srinivas Kandagatla
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_address.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include "core.h"
+
+#define STM32_GPIO_MODER	0x00
+#define STM32_GPIO_TYPER	0x04
+#define STM32_GPIO_SPEEDR	0x08
+#define STM32_GPIO_PUPDR	0x0c
+#define STM32_GPIO_IDR		0x10
+#define STM32_GPIO_ODR		0x14
+#define STM32_GPIO_BSRR		0x18
+#define STM32_GPIO_LCKR		0x1c
+#define STM32_GPIO_AFRL		0x20
+#define STM32_GPIO_AFRH		0x24
+
+#define STM32_GPIO_PINS_PER_BANK 16
+#define OF_GPIO_ARGS_MIN 4
+
+#define STM32_PINCONF_UNPACK(conf, param)\
+				((conf >> STM32_PINCONF_ ##param ##_SHIFT) \
+				& STM32_PINCONF_ ##param ##_MASK)
+
+#define STM32_PINCONF_PACK(conf, val, param)	(conf |=\
+				((val & STM32_PINCONF_ ##param ##_MASK) << \
+					STM32_PINCONF_ ##param ##_SHIFT))
+
+#define STM32_PINCONF_SPEED_MASK		0x3
+#define STM32_PINCONF_SPEED_SHIFT		3
+#define STM32_PINCONF_UNPACK_SPEED(conf)\
+				STM32_PINCONF_UNPACK(conf, SPEED)
+#define STM32_PINCONF_PACK_SPEED(conf, val)\
+				STM32_PINCONF_PACK(conf, val, SPEED)
+
+#define STM32_PINCONF_TYPE_MASK			0x1
+#define STM32_PINCONF_TYPE_SHIFT		2
+#define STM32_PINCONF_UNPACK_TYPE(conf)\
+				STM32_PINCONF_UNPACK(conf, TYPE)
+#define STM32_PINCONF_PACK_TYPE(conf, val)\
+				STM32_PINCONF_PACK(conf, val, TYPE)
+
+#define STM32_PINCONF_PUPD_MASK			0x3
+#define STM32_PINCONF_PUPD_SHIFT		0
+#define STM32_PINCONF_UNPACK_PUPD(conf)\
+				STM32_PINCONF_UNPACK(conf, PUPD)
+#define STM32_PINCONF_PACK_PUPD(conf, val)\
+				STM32_PINCONF_PACK(conf, val, PUPD)
+
+
+#define STM32_PINCONF_ALT_MASK			0xf
+#define STM32_PINCONF_ALT_SHIFT		2
+#define STM32_PINCONF_UNPACK_ALT(conf)\
+				STM32_PINCONF_UNPACK(conf, ALT)
+#define STM32_PINCONF_PACK_ALT(conf, val)\
+				STM32_PINCONF_PACK(conf, val, ALT)
+
+#define STM32_PINCONF_MODE_MASK			0x3
+#define STM32_PINCONF_MODE_SHIFT		0
+#define STM32_PINCONF_UNPACK_MODE(conf)\
+				STM32_PINCONF_UNPACK(conf, MODE)
+#define STM32_PINCONF_PACK_MODE(conf, val)\
+				STM32_PINCONF_PACK(conf, val, MODE)
+
+
+
+#define gpio_range_to_bank(chip) \
+		container_of(chip, struct stm32_gpio_bank, range)
+
+#define gpio_chip_to_bank(chip) \
+		container_of(chip, struct stm32_gpio_bank, gpio_chip)
+
+struct stm32_pinconf {
+	int		pin;
+	const char	*name;
+	unsigned long	config;
+	int		altfunc;
+};
+
+struct stm32_pmx_func {
+	const char	*name;
+	const char	**groups;
+	unsigned	ngroups;
+};
+
+struct stm32_pctl_group {
+	const char		*name;
+	unsigned int		*pins;
+	unsigned		npins;
+	struct stm32_pinconf	*pin_conf;
+};
+
+struct stm32_gpio_bank {
+	void __iomem *base;
+	struct gpio_chip		gpio_chip;
+	struct pinctrl_gpio_range	range;
+	spinlock_t                      lock;
+};
+
+struct stm32_pinctrl {
+	struct device		*dev;
+	struct pinctrl_dev		*pctl;
+	struct stm32_gpio_bank	*banks;
+	int			nbanks;
+	struct stm32_pmx_func	*functions;
+	int			nfunctions;
+	struct stm32_pctl_group	*groups;
+	int			ngroups;
+};
+
+static inline int stm32_gpio_pin(int gpio)
+{
+	return gpio % STM32_GPIO_PINS_PER_BANK;
+}
+
+/* Pinconf  */
+static void stm32_pinconf_set_config(struct stm32_gpio_bank *bank,
+				int pin, unsigned long config)
+{
+	u32 type, speed, pupd, val;
+	unsigned long flags;
+
+	type = STM32_PINCONF_UNPACK_TYPE(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_TYPER);
+	val &= ~BIT(pin);
+	val |= type << pin;
+	writel_relaxed(val, bank->base + STM32_GPIO_TYPER);
+	spin_unlock_irqrestore(&bank->lock, flags);
+
+	speed = STM32_PINCONF_UNPACK_SPEED(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_SPEEDR);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= speed << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_SPEEDR);
+	spin_unlock_irqrestore(&bank->lock, flags);
+
+	pupd = STM32_PINCONF_UNPACK_PUPD(config);
+	spin_lock_irqsave(&bank->lock, flags);
+	val = readl_relaxed(bank->base + STM32_GPIO_PUPDR);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= pupd << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_PUPDR);
+	spin_unlock_irqrestore(&bank->lock, flags);
+}
+
+static void stm32_pinconf_get_config(struct stm32_gpio_bank *bank,
+				int pin, unsigned long *config)
+{
+	u32 val;
+
+	val = readl_relaxed(bank->base + STM32_GPIO_TYPER);
+	val = val >> pin;
+	STM32_PINCONF_PACK_TYPE(*config, val);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_SPEEDR);
+	val = val >> (pin * 2);
+	STM32_PINCONF_PACK_SPEED(*config, val);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_PUPDR);
+	val = val >> (pin * 2);
+	STM32_PINCONF_PACK_PUPD(*config, val);
+}
+
+static int stm32_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin_id,
+			unsigned long *configs, unsigned num_configs)
+{
+	struct pinctrl_gpio_range *range =
+			 pinctrl_find_gpio_range_from_pin(pctldev, pin_id);
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+	int pin = stm32_gpio_pin(pin_id);
+	int i;
+
+	for (i = 0; i < num_configs; i++)
+		stm32_pinconf_set_config(bank, pin, configs[i]);
+
+	return 0;
+}
+
+static int stm32_pinconf_get(struct pinctrl_dev *pctldev,
+			     unsigned pin_id, unsigned long *config)
+{
+	struct pinctrl_gpio_range *range =
+			 pinctrl_find_gpio_range_from_pin(pctldev, pin_id);
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+	int pin = stm32_gpio_pin(pin_id);
+
+	*config = 0;
+	stm32_pinconf_get_config(bank, pin, config);
+
+	return 0;
+}
+
+static void stm32_pinconf_dbg_show(struct pinctrl_dev *pctldev,
+				   struct seq_file *s, unsigned pin_id)
+{
+	unsigned long config;
+
+	stm32_pinconf_get(pctldev, pin_id, &config);
+
+	seq_printf(s, "[PUPD:%ld,TYPE:%ld,SPEED:%ld]\n",
+		STM32_PINCONF_UNPACK_PUPD(config),
+		STM32_PINCONF_UNPACK_TYPE(config),
+		STM32_PINCONF_UNPACK_SPEED(config));
+}
+
+static struct pinconf_ops stm32_confops = {
+	.pin_config_get		= stm32_pinconf_get,
+	.pin_config_set		= stm32_pinconf_set,
+	.pin_config_dbg_show	= stm32_pinconf_dbg_show,
+};
+
+static void stm32_pctl_set_function(struct stm32_gpio_bank *bank,
+		int pin_id, int function)
+{
+	u32 mode, alt, val;
+	int pin = stm32_gpio_pin(pin_id);
+	int alt_shift = (pin % 8) * 4;
+	int alt_offset = STM32_GPIO_AFRL + (pin / 8) * 4;
+	unsigned long flags;
+
+	mode = STM32_PINCONF_UNPACK_MODE(function);
+	alt = STM32_PINCONF_UNPACK_ALT(function);
+
+	spin_lock_irqsave(&bank->lock, flags);
+
+	val = readl_relaxed(bank->base + alt_offset);
+	val &= ~GENMASK(alt_shift + 3, alt_shift);
+	val |= (alt << alt_shift);
+	writel_relaxed(val, bank->base + alt_offset);
+
+	val = readl_relaxed(bank->base + STM32_GPIO_MODER);
+	val &= ~GENMASK(pin * 2 + 1, pin * 2);
+	val |= mode << (pin * 2);
+	writel_relaxed(val, bank->base + STM32_GPIO_MODER);
+
+	spin_unlock_irqrestore(&bank->lock, flags);
+}
+
+/* Pinmux */
+static int stm32_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->nfunctions;
+}
+
+static const char *stm32_pmx_get_fname(struct pinctrl_dev *pctldev,
+	unsigned selector)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->functions[selector].name;
+}
+
+static int stm32_pmx_get_groups(struct pinctrl_dev *pctldev,
+	unsigned selector, const char * const **grps, unsigned * const ngrps)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	*grps = info->functions[selector].groups;
+	*ngrps = info->functions[selector].ngroups;
+
+	return 0;
+}
+
+static int stm32_pmx_set_mux(struct pinctrl_dev *pctldev, unsigned fselector,
+			unsigned group)
+{
+	struct pinctrl_gpio_range *range;
+	struct stm32_gpio_bank *bank;
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	struct stm32_pinconf *conf = info->groups[group].pin_conf;
+	int i;
+
+	for (i = 0; i < info->groups[group].npins; i++) {
+		range = pinctrl_find_gpio_range_from_pin(pctldev, conf[i].pin);
+		bank = gpio_range_to_bank(range);
+		stm32_pctl_set_function(bank, conf[i].pin, conf[i].altfunc);
+	}
+
+	return 0;
+}
+
+static int stm32_pmx_set_gpio_direction(struct pinctrl_dev *pctldev,
+			struct pinctrl_gpio_range *range, unsigned gpio,
+			bool input)
+{
+	struct stm32_gpio_bank *bank = gpio_range_to_bank(range);
+
+	stm32_pctl_set_function(bank, gpio, !input);
+
+	return 0;
+}
+
+static struct pinmux_ops stm32_pmxops = {
+	.get_functions_count	= stm32_pmx_get_funcs_count,
+	.get_function_name	= stm32_pmx_get_fname,
+	.get_function_groups	= stm32_pmx_get_groups,
+	.set_mux		= stm32_pmx_set_mux,
+	.gpio_set_direction	= stm32_pmx_set_gpio_direction,
+};
+
+/* Pinctrl Groups */
+static int stm32_pctl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->ngroups;
+}
+
+static const char *stm32_pctl_get_group_name(struct pinctrl_dev *pctldev,
+				       unsigned selector)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	return info->groups[selector].name;
+}
+
+static int stm32_pctl_get_group_pins(struct pinctrl_dev *pctldev,
+	unsigned selector, const unsigned **pins, unsigned *npins)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+
+	if (selector >= info->ngroups)
+		return -EINVAL;
+
+	*pins = info->groups[selector].pins;
+	*npins = info->groups[selector].npins;
+
+	return 0;
+}
+
+static const inline struct stm32_pctl_group *stm32_pctl_find_group_by_name(
+	const struct stm32_pinctrl *info, const char *name)
+{
+	int i;
+
+	for (i = 0; i < info->ngroups; i++) {
+		if (!strcmp(info->groups[i].name, name))
+			return &info->groups[i];
+	}
+
+	return NULL;
+}
+
+static int stm32_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
+	struct device_node *np, struct pinctrl_map **map, unsigned *num_maps)
+{
+	struct stm32_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
+	const struct stm32_pctl_group *grp;
+	struct pinctrl_map *new_map;
+	struct device_node *parent;
+	int map_num, i;
+
+	grp = stm32_pctl_find_group_by_name(info, np->name);
+	if (!grp) {
+		dev_err(info->dev, "unable to find group for node %s\n",
+			np->name);
+		return -EINVAL;
+	}
+
+	map_num = grp->npins + 1;
+	new_map = devm_kzalloc(pctldev->dev,
+				sizeof(*new_map) * map_num, GFP_KERNEL);
+	if (!new_map)
+		return -ENOMEM;
+
+	parent = of_get_parent(np);
+	if (!parent) {
+		devm_kfree(pctldev->dev, new_map);
+		return -EINVAL;
+	}
+
+	*map = new_map;
+	*num_maps = map_num;
+	new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
+	new_map[0].data.mux.function = parent->name;
+	new_map[0].data.mux.group = np->name;
+	of_node_put(parent);
+
+	/* create config map per pin */
+	new_map++;
+	for (i = 0; i < grp->npins; i++) {
+		new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;
+		new_map[i].data.configs.group_or_pin =
+				pin_get_name(pctldev, grp->pins[i]);
+		new_map[i].data.configs.configs = &grp->pin_conf[i].config;
+		new_map[i].data.configs.num_configs = 1;
+	}
+	dev_info(pctldev->dev, "maps: function %s group %s num %d\n",
+		(*map)->data.mux.function, grp->name, map_num);
+
+	return 0;
+}
+
+static void stm32_pctl_dt_free_map(struct pinctrl_dev *pctldev,
+			struct pinctrl_map *map, unsigned num_maps)
+{
+}
+
+static struct pinctrl_ops stm32_pctlops = {
+	.get_groups_count	= stm32_pctl_get_groups_count,
+	.get_group_pins		= stm32_pctl_get_group_pins,
+	.get_group_name		= stm32_pctl_get_group_name,
+	.dt_node_to_map		= stm32_pctl_dt_node_to_map,
+	.dt_free_map		= stm32_pctl_dt_free_map,
+};
+
+static void stm32_pctl_dt_child_count(struct stm32_pinctrl *info,
+				     struct device_node *np)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(np, child) {
+		if (of_property_read_bool(child, "gpio-controller")) {
+			info->nbanks++;
+		} else {
+			info->nfunctions++;
+			info->ngroups += of_get_child_count(child);
+		}
+	}
+}
+
+static int stm32_pctl_dt_parse_groups(struct device_node *np,
+	struct stm32_pctl_group *grp, struct stm32_pinctrl *info, int idx)
+{
+	const __be32 *list;
+	struct property *pp;
+	struct stm32_pinconf *conf;
+	struct device_node *pins;
+	int i = 0, npins = 0, nr_props;
+
+	pins = of_get_child_by_name(np, "st,pins");
+	if (!pins)
+		return -ENODATA;
+
+	for_each_property_of_node(pins, pp) {
+		/* Skip those we do not want to proceed */
+		if (!strcmp(pp->name, "name"))
+			continue;
+
+		if (pp  && (pp->length / sizeof(__be32)) >= OF_GPIO_ARGS_MIN) {
+			npins++;
+		} else {
+			pr_warn("Invalid st,pins in %s node\n", np->name);
+			return -EINVAL;
+		}
+	}
+
+	grp->npins = npins;
+	grp->name = np->name;
+	grp->pins = devm_kzalloc(info->dev, npins * sizeof(u32), GFP_KERNEL);
+	grp->pin_conf = devm_kzalloc(info->dev,
+					npins * sizeof(*conf), GFP_KERNEL);
+
+	if (!grp->pins || !grp->pin_conf)
+		return -ENOMEM;
+
+	/* <bank offset mux pull type speed> */
+	for_each_property_of_node(pins, pp) {
+		if (!strcmp(pp->name, "name"))
+			continue;
+		nr_props = pp->length / sizeof(u32);
+		list = pp->value;
+		conf = &grp->pin_conf[i];
+
+		/* bank & offset */
+		be32_to_cpup(list++);
+		be32_to_cpup(list++);
+		conf->pin = of_get_named_gpio(pins, pp->name, 0);
+		conf->name = pp->name;
+		grp->pins[i] = conf->pin;
+		/* mux */
+		conf->altfunc = be32_to_cpup(list++);
+		conf->config = 0;
+		/* pull-up/down */
+		conf->config |= be32_to_cpup(list++);
+		if (nr_props > OF_GPIO_ARGS_MIN) {
+			/* push-pull/open-drain */
+			conf->config |= be32_to_cpup(list++);
+			/* speed */
+			conf->config |= be32_to_cpup(list++);
+		}
+		i++;
+	}
+	of_node_put(pins);
+
+	return 0;
+}
+
+static int stm32_pctl_parse_functions(struct device_node *np,
+			struct stm32_pinctrl *info, u32 index, int *grp_index)
+{
+	struct device_node *child;
+	struct stm32_pmx_func *func;
+	struct stm32_pctl_group *grp;
+	int i = 0, ret;
+
+	func = &info->functions[index];
+	func->name = np->name;
+	func->ngroups = of_get_child_count(np);
+	if (func->ngroups == 0) {
+		dev_err(info->dev, "No groups defined\n");
+		return -EINVAL;
+	}
+	func->groups = devm_kzalloc(info->dev,
+			func->ngroups * sizeof(char *), GFP_KERNEL);
+	if (!func->groups)
+		return -ENOMEM;
+
+	for_each_child_of_node(np, child) {
+		func->groups[i] = child->name;
+		grp = &info->groups[*grp_index];
+		*grp_index += 1;
+		ret = stm32_pctl_dt_parse_groups(child, grp, info, i++);
+		if (ret)
+			return ret;
+	}
+	dev_info(info->dev, "Function[%d\t name:%s,\tgroups:%d]\n",
+				index, func->name, func->ngroups);
+
+	return 0;
+}
+
+static inline void __stm32_gpio_set(struct stm32_gpio_bank *bank,
+	unsigned offset, int value)
+{
+	if (!value)
+		offset += STM32_GPIO_PINS_PER_BANK;
+
+	writel_relaxed(BIT(offset), bank->base + STM32_GPIO_BSRR);
+}
+
+static int stm32_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void stm32_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_free_gpio(chip->base + offset);
+}
+
+static int stm32_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	return !!(readl_relaxed(bank->base + STM32_GPIO_IDR) & BIT(offset));
+}
+
+static void stm32_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	__stm32_gpio_set(bank, offset, value);
+}
+
+static int stm32_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_gpio_direction_input(chip->base + offset);
+
+	return 0;
+}
+
+static int stm32_gpio_direction_output(struct gpio_chip *chip,
+	unsigned offset, int value)
+{
+	struct stm32_gpio_bank *bank = gpio_chip_to_bank(chip);
+
+	__stm32_gpio_set(bank, offset, value);
+	pinctrl_gpio_direction_output(chip->base + offset);
+
+	return 0;
+}
+
+static struct gpio_chip stm32_gpio_template = {
+	.request		= stm32_gpio_request,
+	.free			= stm32_gpio_free,
+	.get			= stm32_gpio_get,
+	.set			= stm32_gpio_set,
+	.direction_input	= stm32_gpio_direction_input,
+	.direction_output	= stm32_gpio_direction_output,
+	.ngpio			= STM32_GPIO_PINS_PER_BANK,
+};
+
+static int stm32_gpiolib_register_bank(struct stm32_pinctrl *info,
+	int bank_nr, struct device_node *np)
+{
+	struct stm32_gpio_bank *bank = &info->banks[bank_nr];
+	struct pinctrl_gpio_range *range = &bank->range;
+	struct device *dev = info->dev;
+	struct resource res;
+	struct reset_control *rstc;
+	int bank_num = of_alias_get_id(np, "gpio");
+	int err;
+
+	rstc = of_reset_control_get(np, NULL);
+	if (!IS_ERR(rstc))
+		reset_control_deassert(rstc);
+
+	if (of_address_to_resource(np, 0, &res))
+		return -ENODEV;
+
+	bank->base = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(bank->base))
+		return PTR_ERR(bank->base);
+
+	bank->gpio_chip = stm32_gpio_template;
+	bank->gpio_chip.base = bank_num * STM32_GPIO_PINS_PER_BANK;
+	bank->gpio_chip.of_node = np;
+	bank->gpio_chip.dev = dev;
+	spin_lock_init(&bank->lock);
+
+	of_property_read_string(np, "st,bank-name", &range->name);
+	bank->gpio_chip.label = range->name;
+
+	range->id = bank_num;
+	range->pin_base = range->base = range->id * STM32_GPIO_PINS_PER_BANK;
+	range->npins = bank->gpio_chip.ngpio;
+	range->gc = &bank->gpio_chip;
+	err  = gpiochip_add(&bank->gpio_chip);
+	if (err) {
+		dev_err(dev, "Failed to add gpiochip(%d)!\n", bank_num);
+		return err;
+	}
+	dev_info(dev, "%s bank added.\n", range->name);
+
+	return 0;
+}
+
+static int stm32_pctl_probe_dt(struct platform_device *pdev,
+	struct pinctrl_desc *pctl_desc, struct stm32_pinctrl *info)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct pinctrl_pin_desc *pdesc;
+	struct device_node *child;
+	int grp_index = 0;
+	int i = 0, j = 0, k = 0, bank = 0,  ret = 0;
+
+	stm32_pctl_dt_child_count(info, np);
+	if (!info->nbanks) {
+		dev_err(&pdev->dev, "you need atleast one gpio bank\n");
+		return -EINVAL;
+	}
+
+	dev_info(&pdev->dev, "nbanks = %d\n", info->nbanks);
+	dev_info(&pdev->dev, "nfunctions = %d\n", info->nfunctions);
+	dev_info(&pdev->dev, "ngroups = %d\n", info->ngroups);
+
+	info->functions = devm_kzalloc(&pdev->dev,
+		info->nfunctions * sizeof(*info->functions), GFP_KERNEL);
+
+	info->groups = devm_kzalloc(&pdev->dev,
+			info->ngroups * sizeof(*info->groups), GFP_KERNEL);
+
+	info->banks = devm_kzalloc(&pdev->dev,
+			info->nbanks * sizeof(*info->banks), GFP_KERNEL);
+
+	if (!info->functions || !info->groups || !info->banks)
+		return -ENOMEM;
+
+	pctl_desc->npins = info->nbanks * STM32_GPIO_PINS_PER_BANK;
+	pdesc =	devm_kzalloc(&pdev->dev,
+			sizeof(*pdesc) * pctl_desc->npins, GFP_KERNEL);
+	if (!pdesc)
+		return -ENOMEM;
+
+	pctl_desc->pins = pdesc;
+
+	for_each_child_of_node(np, child) {
+		if (of_property_read_bool(child, "gpio-controller")) {
+			const char *bank_name;
+
+			ret = stm32_gpiolib_register_bank(info, bank, child);
+			if (ret)
+				return ret;
+
+			k = info->banks[bank].range.pin_base;
+			bank_name = info->banks[bank].range.name;
+			for (j = 0; j < STM32_GPIO_PINS_PER_BANK; j++, k++) {
+				pdesc->number = k;
+				pdesc->name = kasprintf(GFP_KERNEL, "%s[%d]",
+							bank_name, j);
+				pdesc++;
+			}
+			bank++;
+		} else {
+			ret = stm32_pctl_parse_functions(child, info,
+							i++, &grp_index);
+			if (ret) {
+				dev_err(&pdev->dev, "No functions found.\n");
+				return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int stm32_pctl_probe(struct platform_device *pdev)
+{
+	struct stm32_pinctrl *info;
+	struct pinctrl_desc *pctl_desc;
+	int ret, i;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "device not found.\n");
+		return -EINVAL;
+	}
+
+	pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL);
+	if (!pctl_desc)
+		return -ENOMEM;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	platform_set_drvdata(pdev, info);
+	ret = stm32_pctl_probe_dt(pdev, pctl_desc, info);
+	if (ret)
+		return ret;
+
+	pctl_desc->owner	= THIS_MODULE;
+	pctl_desc->pctlops	= &stm32_pctlops;
+	pctl_desc->pmxops	= &stm32_pmxops;
+	pctl_desc->confops	= &stm32_confops;
+	pctl_desc->name		= dev_name(&pdev->dev);
+
+	info->pctl = pinctrl_register(pctl_desc, &pdev->dev, info);
+	if (!info->pctl) {
+		dev_err(&pdev->dev, "Failed pinctrl registration\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < info->nbanks; i++)
+		pinctrl_add_gpio_range(info->pctl, &info->banks[i].range);
+
+	return 0;
+}
+
+static struct of_device_id stm32_pctl_of_match[] = {
+	{ .compatible = "st,stm32-pinctrl" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver stm32_pctl_driver = {
+	.driver = {
+		.name = "stm32-pinctrl",
+		.owner = THIS_MODULE,
+		.of_match_table = stm32_pctl_of_match,
+	},
+	.probe = stm32_pctl_probe,
+};
+
+static int __init stm32_pctl_init(void)
+{
+	return platform_driver_register(&stm32_pctl_driver);
+}
+arch_initcall(stm32_pctl_init);
diff --git a/include/dt-bindings/pinctrl/pinctrl-stm32.h b/include/dt-bindings/pinctrl/pinctrl-stm32.h
new file mode 100644
index 0000000..3e93a86
--- /dev/null
+++ b/include/dt-bindings/pinctrl/pinctrl-stm32.h
@@ -0,0 +1,43 @@
+#ifndef _DT_BINDINGS_PINCTRL_STM32_H
+#define _DT_BINDINGS_PINCTRL_STM32_H
+
+/* Modes */
+#define IN		0
+#define OUT		1
+#define ALT		2
+#define ANALOG		3
+
+/* Alternate functions */
+#define ALT0		((0 << 2) | ALT)
+#define ALT1		((1 << 2) | ALT)
+#define ALT2		((2 << 2) | ALT)
+#define ALT3		((3 << 2) | ALT)
+#define ALT4		((4 << 2) | ALT)
+#define ALT5		((5 << 2) | ALT)
+#define ALT6		((6 << 2) | ALT)
+#define ALT7		((7 << 2) | ALT)
+#define ALT8		((8 << 2) | ALT)
+#define ALT9		((9 << 2) | ALT)
+#define ALT10		((10 << 2) | ALT)
+#define ALT11		((11 << 2) | ALT)
+#define ALT12		((12 << 2) | ALT)
+#define ALT13		((13 << 2) | ALT)
+#define ALT14		((14 << 2) | ALT)
+#define ALT15		((15 << 2) | ALT)
+
+/* Pull-Up/Down */
+#define NO_PULL		0
+#define PULL_UP		1
+#define PULL_DOWN	2
+
+/* Type */
+#define PUSH_PULL	(0 << 2)
+#define OPEN_DRAIN	(1 << 2)
+
+/* Speed */
+#define LOW_SPEED	(0 << 3)
+#define MEDIUM_SPEED	(1 << 3)
+#define FAST_SPEED	(2 << 3)
+#define HIGH_SPEED	(3 << 3)
+
+#endif /* _DT_BINDINGS_PINCTRL_STM32_H */
-- 
1.9.1

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