/*
 * Pinctrl driver for Rockchip SoCs
 *
 * Copyright (c) 2013 MundoReader S.L.
 * Author: Heiko Stuebner <heiko@sntech.de>
 *
 * With some ideas taken from pinctrl-samsung:
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 * Copyright (c) 2012 Linaro Ltd
 *		http://www.linaro.org
 *
 * and pinctrl-at91:
 * Copyright (C) 2011-2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/gpio.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/clk.h>
#include <dt-bindings/pinctrl/rockchip.h>

#include "core.h"
#include "pinconf.h"

/* GPIO control registers */
#define GPIO_SWPORT_DR		0x00
#define GPIO_SWPORT_DDR		0x04
#define GPIO_INTEN		0x30
#define GPIO_INTMASK		0x34
#define GPIO_INTTYPE_LEVEL	0x38
#define GPIO_INT_POLARITY	0x3c
#define GPIO_INT_STATUS		0x40
#define GPIO_INT_RAWSTATUS	0x44
#define GPIO_DEBOUNCE		0x48
#define GPIO_PORTS_EOI		0x4c
#define GPIO_EXT_PORT		0x50
#define GPIO_LS_SYNC		0x60

/**
 * @reg_base: register base of the gpio bank
 * @clk: clock of the gpio bank
 * @irq: interrupt of the gpio bank
 * @pin_base: first pin number
 * @nr_pins: number of pins in this bank
 * @name: name of the bank
 * @bank_num: number of the bank, to account for holes
 * @valid: are all necessary informations present
 * @of_node: dt node of this bank
 * @drvdata: common pinctrl basedata
 * @domain: irqdomain of the gpio bank
 * @gpio_chip: gpiolib chip
 * @grange: gpio range
 * @slock: spinlock for the gpio bank
 */
struct rockchip_pin_bank {
	void __iomem			*reg_base;
	struct clk			*clk;
	int				irq;
	u32				pin_base;
	u8				nr_pins;
	char				*name;
	u8				bank_num;
	bool				valid;
	struct device_node		*of_node;
	struct rockchip_pinctrl		*drvdata;
	struct irq_domain		*domain;
	struct gpio_chip		gpio_chip;
	struct pinctrl_gpio_range	grange;
	spinlock_t			slock;

};

#define PIN_BANK(id, pins, label)			\
	{						\
		.bank_num	= id,			\
		.nr_pins	= pins,			\
		.name		= label,		\
	}

/**
 * @pull_auto: some SoCs don't allow pulls to be specified as up or down, but
 *	       instead decide this automatically based on the pad-type.
 */
struct rockchip_pin_ctrl {
	struct rockchip_pin_bank	*pin_banks;
	u32				nr_banks;
	u32				nr_pins;
	char				*label;
	int				mux_offset;
	int				pull_offset;
	bool				pull_auto;
	int				pull_bank_stride;
};

struct rockchip_pin_config {
	unsigned int		func;
	unsigned long		*configs;
	unsigned int		nconfigs;
};

/**
 * struct rockchip_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.
 * @npins: number of pins included in this group.
 * @func: the mux function number to be programmed when selected.
 * @configs: the config values to be set for each pin
 * @nconfigs: number of configs for each pin
 */
struct rockchip_pin_group {
	const char			*name;
	unsigned int			npins;
	unsigned int			*pins;
	struct rockchip_pin_config	*data;
};

/**
 * struct rockchip_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 rockchip_pmx_func {
	const char		*name;
	const char		**groups;
	u8			ngroups;
};

struct rockchip_pinctrl {
	void __iomem			*reg_base;
	struct device			*dev;
	struct rockchip_pin_ctrl	*ctrl;
	struct pinctrl_desc		pctl;
	struct pinctrl_dev		*pctl_dev;
	struct rockchip_pin_group	*groups;
	unsigned int			ngroups;
	struct rockchip_pmx_func	*functions;
	unsigned int			nfunctions;
};

static inline struct rockchip_pin_bank *gc_to_pin_bank(struct gpio_chip *gc)
{
	return container_of(gc, struct rockchip_pin_bank, gpio_chip);
}

static const inline struct rockchip_pin_group *pinctrl_name_to_group(
					const struct rockchip_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;
}

/*
 * 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 struct rockchip_pin_bank *pin_to_bank(struct rockchip_pinctrl *info,
								unsigned pin)
{
	struct rockchip_pin_bank *b = info->ctrl->pin_banks;

	while (pin >= (b->pin_base + b->nr_pins))
		b++;

	return b;
}

static struct rockchip_pin_bank *bank_num_to_bank(
					struct rockchip_pinctrl *info,
					unsigned num)
{
	struct rockchip_pin_bank *b = info->ctrl->pin_banks;
	int i;

	for (i = 0; i < info->ctrl->nr_banks; i++, b++) {
		if (b->bank_num == num)
			return b;
	}

	return ERR_PTR(-EINVAL);
}

/*
 * Pinctrl_ops handling
 */

static int rockchip_get_groups_count(struct pinctrl_dev *pctldev)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

	return info->ngroups;
}

static const char *rockchip_get_group_name(struct pinctrl_dev *pctldev,
							unsigned selector)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

	return info->groups[selector].name;
}

static int rockchip_get_group_pins(struct pinctrl_dev *pctldev,
				      unsigned selector, const unsigned **pins,
				      unsigned *npins)
{
	struct rockchip_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 int rockchip_dt_node_to_map(struct pinctrl_dev *pctldev,
				 struct device_node *np,
				 struct pinctrl_map **map, unsigned *num_maps)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	const struct rockchip_pin_group *grp;
	struct pinctrl_map *new_map;
	struct device_node *parent;
	int map_num = 1;
	int i;

	/*
	 * first find the group of this node and check if we need to create
	 * config maps for pins
	 */
	grp = pinctrl_name_to_group(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;
	new_map = devm_kzalloc(pctldev->dev, sizeof(*new_map) * map_num,
								GFP_KERNEL);
	if (!new_map)
		return -ENOMEM;

	*map = new_map;
	*num_maps = map_num;

	/* create mux map */
	parent = of_get_parent(np);
	if (!parent) {
		devm_kfree(pctldev->dev, new_map);
		return -EINVAL;
	}
	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 */
	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->data[i].configs;
		new_map[i].data.configs.num_configs = grp->data[i].nconfigs;
	}

	dev_dbg(pctldev->dev, "maps: function %s group %s num %d\n",
		(*map)->data.mux.function, (*map)->data.mux.group, map_num);

	return 0;
}

static void rockchip_dt_free_map(struct pinctrl_dev *pctldev,
				    struct pinctrl_map *map, unsigned num_maps)
{
}

static const struct pinctrl_ops rockchip_pctrl_ops = {
	.get_groups_count	= rockchip_get_groups_count,
	.get_group_name		= rockchip_get_group_name,
	.get_group_pins		= rockchip_get_group_pins,
	.dt_node_to_map		= rockchip_dt_node_to_map,
	.dt_free_map		= rockchip_dt_free_map,
};

/*
 * Hardware access
 */

/*
 * Set a new mux function for a pin.
 *
 * The register is divided into the upper and lower 16 bit. When changing
 * a value, the previous register value is not read and changed. Instead
 * it seems the changed bits are marked in the upper 16 bit, while the
 * changed value gets set in the same offset in the lower 16 bit.
 * All pin settings seem to be 2 bit wide in both the upper and lower
 * parts.
 * @bank: pin bank to change
 * @pin: pin to change
 * @mux: new mux function to set
 */
static void rockchip_set_mux(struct rockchip_pin_bank *bank, int pin, int mux)
{
	struct rockchip_pinctrl *info = bank->drvdata;
	void __iomem *reg = info->reg_base + info->ctrl->mux_offset;
	unsigned long flags;
	u8 bit;
	u32 data;

	dev_dbg(info->dev, "setting mux of GPIO%d-%d to %d\n",
						bank->bank_num, pin, mux);

	/* get basic quadrupel of mux registers and the correct reg inside */
	reg += bank->bank_num * 0x10;
	reg += (pin / 8) * 4;
	bit = (pin % 8) * 2;

	spin_lock_irqsave(&bank->slock, flags);

	data = (3 << (bit + 16));
	data |= (mux & 3) << bit;
	writel(data, reg);

	spin_unlock_irqrestore(&bank->slock, flags);
}

static int rockchip_get_pull(struct rockchip_pin_bank *bank, int pin_num)
{
	struct rockchip_pinctrl *info = bank->drvdata;
	struct rockchip_pin_ctrl *ctrl = info->ctrl;
	void __iomem *reg;
	u8 bit;

	/* rk3066b does support any pulls */
	if (!ctrl->pull_offset)
		return PIN_CONFIG_BIAS_DISABLE;

	reg = info->reg_base + ctrl->pull_offset;

	if (ctrl->pull_auto) {
		reg += bank->bank_num * ctrl->pull_bank_stride;
		reg += (pin_num / 16) * 4;
		bit = pin_num % 16;

		return !(readl_relaxed(reg) & BIT(bit))
				? PIN_CONFIG_BIAS_PULL_PIN_DEFAULT
				: PIN_CONFIG_BIAS_DISABLE;
	} else {
		dev_err(info->dev, "pull support for rk31xx not implemented\n");
		return -EIO;
	}
}

static int rockchip_set_pull(struct rockchip_pin_bank *bank,
					int pin_num, int pull)
{
	struct rockchip_pinctrl *info = bank->drvdata;
	struct rockchip_pin_ctrl *ctrl = info->ctrl;
	void __iomem *reg;
	unsigned long flags;
	u8 bit;
	u32 data;

	dev_dbg(info->dev, "setting pull of GPIO%d-%d to %d\n",
		 bank->bank_num, pin_num, pull);

	/* rk3066b does support any pulls */
	if (!ctrl->pull_offset)
		return pull ? -EINVAL : 0;

	reg = info->reg_base + ctrl->pull_offset;

	if (ctrl->pull_auto) {
		if (pull != PIN_CONFIG_BIAS_PULL_PIN_DEFAULT &&
					pull != PIN_CONFIG_BIAS_DISABLE) {
			dev_err(info->dev, "only PIN_DEFAULT and DISABLE allowed\n");
			return -EINVAL;
		}

		reg += bank->bank_num * ctrl->pull_bank_stride;
		reg += (pin_num / 16) * 4;
		bit = pin_num % 16;

		spin_lock_irqsave(&bank->slock, flags);

		data = BIT(bit + 16);
		if (pull == PIN_CONFIG_BIAS_DISABLE)
			data |= BIT(bit);
		writel(data, reg);

		spin_unlock_irqrestore(&bank->slock, flags);
	} else {
		if (pull == PIN_CONFIG_BIAS_PULL_PIN_DEFAULT) {
			dev_err(info->dev, "pull direction (up/down) needs to be specified\n");
			return -EINVAL;
		}

		dev_err(info->dev, "pull support for rk31xx not implemented\n");
		return -EIO;
	}

	return 0;
}

/*
 * Pinmux_ops handling
 */

static int rockchip_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

	return info->nfunctions;
}

static const char *rockchip_pmx_get_func_name(struct pinctrl_dev *pctldev,
					  unsigned selector)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

	return info->functions[selector].name;
}

static int rockchip_pmx_get_groups(struct pinctrl_dev *pctldev,
				unsigned selector, const char * const **groups,
				unsigned * const num_groups)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

	*groups = info->functions[selector].groups;
	*num_groups = info->functions[selector].ngroups;

	return 0;
}

static int rockchip_pmx_enable(struct pinctrl_dev *pctldev, unsigned selector,
							    unsigned group)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	const unsigned int *pins = info->groups[group].pins;
	const struct rockchip_pin_config *data = info->groups[group].data;
	struct rockchip_pin_bank *bank;
	int cnt;

	dev_dbg(info->dev, "enable function %s group %s\n",
		info->functions[selector].name, info->groups[group].name);

	/*
	 * for each pin in the pin group selected, program the correspoding pin
	 * pin function number in the config register.
	 */
	for (cnt = 0; cnt < info->groups[group].npins; cnt++) {
		bank = pin_to_bank(info, pins[cnt]);
		rockchip_set_mux(bank, pins[cnt] - bank->pin_base,
				 data[cnt].func);
	}

	return 0;
}

static void rockchip_pmx_disable(struct pinctrl_dev *pctldev,
					unsigned selector, unsigned group)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	const unsigned int *pins = info->groups[group].pins;
	struct rockchip_pin_bank *bank;
	int cnt;

	dev_dbg(info->dev, "disable function %s group %s\n",
		info->functions[selector].name, info->groups[group].name);

	for (cnt = 0; cnt < info->groups[group].npins; cnt++) {
		bank = pin_to_bank(info, pins[cnt]);
		rockchip_set_mux(bank, pins[cnt] - bank->pin_base, 0);
	}
}

/*
 * 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 rockchip_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
					      struct pinctrl_gpio_range *range,
					      unsigned offset, bool input)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	struct rockchip_pin_bank *bank;
	struct gpio_chip *chip;
	int pin;
	u32 data;

	chip = range->gc;
	bank = gc_to_pin_bank(chip);
	pin = offset - chip->base;

	dev_dbg(info->dev, "gpio_direction for pin %u as %s-%d to %s\n",
		 offset, range->name, pin, input ? "input" : "output");

	rockchip_set_mux(bank, pin, RK_FUNC_GPIO);

	data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
	/* set bit to 1 for output, 0 for input */
	if (!input)
		data |= BIT(pin);
	else
		data &= ~BIT(pin);
	writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);

	return 0;
}

static const struct pinmux_ops rockchip_pmx_ops = {
	.get_functions_count	= rockchip_pmx_get_funcs_count,
	.get_function_name	= rockchip_pmx_get_func_name,
	.get_function_groups	= rockchip_pmx_get_groups,
	.enable			= rockchip_pmx_enable,
	.disable		= rockchip_pmx_disable,
	.gpio_set_direction	= rockchip_pmx_gpio_set_direction,
};

/*
 * Pinconf_ops handling
 */

static bool rockchip_pinconf_pull_valid(struct rockchip_pin_ctrl *ctrl,
					enum pin_config_param pull)
{
	/* rk3066b does support any pulls */
	if (!ctrl->pull_offset)
		return pull ? false : true;

	if (ctrl->pull_auto) {
		if (pull != PIN_CONFIG_BIAS_PULL_PIN_DEFAULT &&
					pull != PIN_CONFIG_BIAS_DISABLE)
			return false;
	} else {
		if (pull == PIN_CONFIG_BIAS_PULL_PIN_DEFAULT)
			return false;
	}

	return true;
}

/* set the pin config settings for a specified pin */
static int rockchip_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
				unsigned long *configs, unsigned num_configs)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	struct rockchip_pin_bank *bank = pin_to_bank(info, pin);
	enum pin_config_param param;
	u16 arg;
	int i;
	int rc;

	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:
			rc =  rockchip_set_pull(bank, pin - bank->pin_base,
				param);
			if (rc)
				return rc;
			break;
		case PIN_CONFIG_BIAS_PULL_UP:
		case PIN_CONFIG_BIAS_PULL_DOWN:
		case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
			if (!rockchip_pinconf_pull_valid(info->ctrl, param))
				return -ENOTSUPP;

			if (!arg)
				return -EINVAL;

			rc = rockchip_set_pull(bank, pin - bank->pin_base,
				param);
			if (rc)
				return rc;
			break;
		default:
			return -ENOTSUPP;
			break;
		}
	} /* for each config */

	return 0;
}

/* get the pin config settings for a specified pin */
static int rockchip_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
							unsigned long *config)
{
	struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
	struct rockchip_pin_bank *bank = pin_to_bank(info, pin);
	enum pin_config_param param = pinconf_to_config_param(*config);

	switch (param) {
	case PIN_CONFIG_BIAS_DISABLE:
		if (rockchip_get_pull(bank, pin - bank->pin_base) != param)
			return -EINVAL;

		*config = 0;
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
	case PIN_CONFIG_BIAS_PULL_DOWN:
	case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
		if (!rockchip_pinconf_pull_valid(info->ctrl, param))
			return -ENOTSUPP;

		if (rockchip_get_pull(bank, pin - bank->pin_base) != param)
			return -EINVAL;

		*config = 1;
		break;
	default:
		return -ENOTSUPP;
		break;
	}

	return 0;
}

static const struct pinconf_ops rockchip_pinconf_ops = {
	.pin_config_get			= rockchip_pinconf_get,
	.pin_config_set			= rockchip_pinconf_set,
};

static const char *gpio_compat = "rockchip,gpio-bank";

static void rockchip_pinctrl_child_count(struct rockchip_pinctrl *info,
						struct device_node *np)
{
	struct device_node *child;

	for_each_child_of_node(np, child) {
		if (of_device_is_compatible(child, gpio_compat))
			continue;

		info->nfunctions++;
		info->ngroups += of_get_child_count(child);
	}
}

static int rockchip_pinctrl_parse_groups(struct device_node *np,
					      struct rockchip_pin_group *grp,
					      struct rockchip_pinctrl *info,
					      u32 index)
{
	struct rockchip_pin_bank *bank;
	int size;
	const __be32 *list;
	int num;
	int i, j;
	int ret;

	dev_dbg(info->dev, "group(%d): %s\n", index, np->name);

	/* Initialise group */
	grp->name = np->name;

	/*
	 * the binding format is rockchip,pins = <bank pin mux CONFIG>,
	 * do sanity check and calculate pins number
	 */
	list = of_get_property(np, "rockchip,pins", &size);
	/* we do not check return since it's safe node passed down */
	size /= sizeof(*list);
	if (!size || size % 4) {
		dev_err(info->dev, "wrong pins number or pins and configs should be by 4\n");
		return -EINVAL;
	}

	grp->npins = size / 4;

	grp->pins = devm_kzalloc(info->dev, grp->npins * sizeof(unsigned int),
						GFP_KERNEL);
	grp->data = devm_kzalloc(info->dev, grp->npins *
					  sizeof(struct rockchip_pin_config),
					GFP_KERNEL);
	if (!grp->pins || !grp->data)
		return -ENOMEM;

	for (i = 0, j = 0; i < size; i += 4, j++) {
		const __be32 *phandle;
		struct device_node *np_config;

		num = be32_to_cpu(*list++);
		bank = bank_num_to_bank(info, num);
		if (IS_ERR(bank))
			return PTR_ERR(bank);

		grp->pins[j] = bank->pin_base + be32_to_cpu(*list++);
		grp->data[j].func = be32_to_cpu(*list++);

		phandle = list++;
		if (!phandle)
			return -EINVAL;

		np_config = of_find_node_by_phandle(be32_to_cpup(phandle));
		ret = pinconf_generic_parse_dt_config(np_config,
				&grp->data[j].configs, &grp->data[j].nconfigs);
		if (ret)
			return ret;
	}

	return 0;
}

static int rockchip_pinctrl_parse_functions(struct device_node *np,
						struct rockchip_pinctrl *info,
						u32 index)
{
	struct device_node *child;
	struct rockchip_pmx_func *func;
	struct rockchip_pin_group *grp;
	int ret;
	static u32 grp_index;
	u32 i = 0;

	dev_dbg(info->dev, "parse function(%d): %s\n", index, np->name);

	func = &info->functions[index];

	/* Initialise function */
	func->name = np->name;
	func->ngroups = of_get_child_count(np);
	if (func->ngroups <= 0)
		return 0;

	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++];
		ret = rockchip_pinctrl_parse_groups(child, grp, info, i++);
		if (ret)
			return ret;
	}

	return 0;
}

static int rockchip_pinctrl_parse_dt(struct platform_device *pdev,
					      struct rockchip_pinctrl *info)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct device_node *child;
	int ret;
	int i;

	rockchip_pinctrl_child_count(info, np);

	dev_dbg(&pdev->dev, "nfunctions = %d\n", info->nfunctions);
	dev_dbg(&pdev->dev, "ngroups = %d\n", info->ngroups);

	info->functions = devm_kzalloc(dev, info->nfunctions *
					      sizeof(struct rockchip_pmx_func),
					      GFP_KERNEL);
	if (!info->functions) {
		dev_err(dev, "failed to allocate memory for function list\n");
		return -EINVAL;
	}

	info->groups = devm_kzalloc(dev, info->ngroups *
					    sizeof(struct rockchip_pin_group),
					    GFP_KERNEL);
	if (!info->groups) {
		dev_err(dev, "failed allocate memory for ping group list\n");
		return -EINVAL;
	}

	i = 0;

	for_each_child_of_node(np, child) {
		if (of_device_is_compatible(child, gpio_compat))
			continue;
		ret = rockchip_pinctrl_parse_functions(child, info, i++);
		if (ret) {
			dev_err(&pdev->dev, "failed to parse function\n");
			return ret;
		}
	}

	return 0;
}

static int rockchip_pinctrl_register(struct platform_device *pdev,
					struct rockchip_pinctrl *info)
{
	struct pinctrl_desc *ctrldesc = &info->pctl;
	struct pinctrl_pin_desc *pindesc, *pdesc;
	struct rockchip_pin_bank *pin_bank;
	int pin, bank, ret;
	int k;

	ctrldesc->name = "rockchip-pinctrl";
	ctrldesc->owner = THIS_MODULE;
	ctrldesc->pctlops = &rockchip_pctrl_ops;
	ctrldesc->pmxops = &rockchip_pmx_ops;
	ctrldesc->confops = &rockchip_pinconf_ops;

	pindesc = devm_kzalloc(&pdev->dev, sizeof(*pindesc) *
			info->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 = info->ctrl->nr_pins;

	pdesc = pindesc;
	for (bank = 0 , k = 0; bank < info->ctrl->nr_banks; bank++) {
		pin_bank = &info->ctrl->pin_banks[bank];
		for (pin = 0; pin < pin_bank->nr_pins; pin++, k++) {
			pdesc->number = k;
			pdesc->name = kasprintf(GFP_KERNEL, "%s-%d",
						pin_bank->name, pin);
			pdesc++;
		}
	}

	info->pctl_dev = pinctrl_register(ctrldesc, &pdev->dev, info);
	if (!info->pctl_dev) {
		dev_err(&pdev->dev, "could not register pinctrl driver\n");
		return -EINVAL;
	}

	for (bank = 0; bank < info->ctrl->nr_banks; ++bank) {
		pin_bank = &info->ctrl->pin_banks[bank];
		pin_bank->grange.name = pin_bank->name;
		pin_bank->grange.id = bank;
		pin_bank->grange.pin_base = pin_bank->pin_base;
		pin_bank->grange.base = pin_bank->gpio_chip.base;
		pin_bank->grange.npins = pin_bank->gpio_chip.ngpio;
		pin_bank->grange.gc = &pin_bank->gpio_chip;
		pinctrl_add_gpio_range(info->pctl_dev, &pin_bank->grange);
	}

	ret = rockchip_pinctrl_parse_dt(pdev, info);
	if (ret) {
		pinctrl_unregister(info->pctl_dev);
		return ret;
	}

	return 0;
}

/*
 * GPIO handling
 */

static int rockchip_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	return pinctrl_request_gpio(chip->base + offset);
}

static void rockchip_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	pinctrl_free_gpio(chip->base + offset);
}

static void rockchip_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
{
	struct rockchip_pin_bank *bank = gc_to_pin_bank(gc);
	void __iomem *reg = bank->reg_base + GPIO_SWPORT_DR;
	unsigned long flags;
	u32 data;

	spin_lock_irqsave(&bank->slock, flags);

	data = readl(reg);
	data &= ~BIT(offset);
	if (value)
		data |= BIT(offset);
	writel(data, reg);

	spin_unlock_irqrestore(&bank->slock, flags);
}

/*
 * Returns the level of the pin for input direction and setting of the DR
 * register for output gpios.
 */
static int rockchip_gpio_get(struct gpio_chip *gc, unsigned offset)
{
	struct rockchip_pin_bank *bank = gc_to_pin_bank(gc);
	u32 data;

	data = readl(bank->reg_base + GPIO_EXT_PORT);
	data >>= 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 rockchip_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 rockchip_gpio_direction_output(struct gpio_chip *gc,
					  unsigned offset, int value)
{
	rockchip_gpio_set(gc, offset, value);
	return pinctrl_gpio_direction_output(gc->base + offset);
}

/*
 * gpiolib gpio_to_irq callback function. Creates a mapping between a GPIO pin
 * and a virtual IRQ, if not already present.
 */
static int rockchip_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct rockchip_pin_bank *bank = gc_to_pin_bank(gc);
	unsigned int virq;

	if (!bank->domain)
		return -ENXIO;

	virq = irq_create_mapping(bank->domain, offset);

	return (virq) ? : -ENXIO;
}

static const struct gpio_chip rockchip_gpiolib_chip = {
	.request = rockchip_gpio_request,
	.free = rockchip_gpio_free,
	.set = rockchip_gpio_set,
	.get = rockchip_gpio_get,
	.direction_input = rockchip_gpio_direction_input,
	.direction_output = rockchip_gpio_direction_output,
	.to_irq = rockchip_gpio_to_irq,
	.owner = THIS_MODULE,
};

/*
 * Interrupt handling
 */

static void rockchip_irq_demux(unsigned int irq, struct irq_desc *desc)
{
	struct irq_chip *chip = irq_get_chip(irq);
	struct rockchip_pin_bank *bank = irq_get_handler_data(irq);
	u32 pend;

	dev_dbg(bank->drvdata->dev, "got irq for bank %s\n", bank->name);

	chained_irq_enter(chip, desc);

	pend = readl_relaxed(bank->reg_base + GPIO_INT_STATUS);

	while (pend) {
		unsigned int virq;

		irq = __ffs(pend);
		pend &= ~BIT(irq);
		virq = irq_linear_revmap(bank->domain, irq);

		if (!virq) {
			dev_err(bank->drvdata->dev, "unmapped irq %d\n", irq);
			continue;
		}

		dev_dbg(bank->drvdata->dev, "handling irq %d\n", irq);

		generic_handle_irq(virq);
	}

	chained_irq_exit(chip, desc);
}

static int rockchip_irq_set_type(struct irq_data *d, unsigned int type)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
	struct rockchip_pin_bank *bank = gc->private;
	u32 mask = BIT(d->hwirq);
	u32 polarity;
	u32 level;
	u32 data;

	if (type & IRQ_TYPE_EDGE_BOTH)
		__irq_set_handler_locked(d->irq, handle_edge_irq);
	else
		__irq_set_handler_locked(d->irq, handle_level_irq);

	irq_gc_lock(gc);

	level = readl_relaxed(gc->reg_base + GPIO_INTTYPE_LEVEL);
	polarity = readl_relaxed(gc->reg_base + GPIO_INT_POLARITY);

	switch (type) {
	case IRQ_TYPE_EDGE_RISING:
		level |= mask;
		polarity |= mask;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		level |= mask;
		polarity &= ~mask;
		break;
	case IRQ_TYPE_LEVEL_HIGH:
		level &= ~mask;
		polarity |= mask;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		level &= ~mask;
		polarity &= ~mask;
		break;
	default:
		irq_gc_unlock(gc);
		return -EINVAL;
	}

	writel_relaxed(level, gc->reg_base + GPIO_INTTYPE_LEVEL);
	writel_relaxed(polarity, gc->reg_base + GPIO_INT_POLARITY);

	irq_gc_unlock(gc);

	/* make sure the pin is configured as gpio input */
	rockchip_set_mux(bank, d->hwirq, RK_FUNC_GPIO);
	data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
	data &= ~mask;
	writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);

	return 0;
}

static int rockchip_interrupts_register(struct platform_device *pdev,
						struct rockchip_pinctrl *info)
{
	struct rockchip_pin_ctrl *ctrl = info->ctrl;
	struct rockchip_pin_bank *bank = ctrl->pin_banks;
	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
	struct irq_chip_generic *gc;
	int ret;
	int i;

	for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
		if (!bank->valid) {
			dev_warn(&pdev->dev, "bank %s is not valid\n",
				 bank->name);
			continue;
		}

		bank->domain = irq_domain_add_linear(bank->of_node, 32,
						&irq_generic_chip_ops, NULL);
		if (!bank->domain) {
			dev_warn(&pdev->dev, "could not initialize irq domain for bank %s\n",
				 bank->name);
			continue;
		}

		ret = irq_alloc_domain_generic_chips(bank->domain, 32, 1,
					 "rockchip_gpio_irq", handle_level_irq,
					 clr, 0, IRQ_GC_INIT_MASK_CACHE);
		if (ret) {
			dev_err(&pdev->dev, "could not alloc generic chips for bank %s\n",
				bank->name);
			irq_domain_remove(bank->domain);
			continue;
		}

		gc = irq_get_domain_generic_chip(bank->domain, 0);
		gc->reg_base = bank->reg_base;
		gc->private = bank;
		gc->chip_types[0].regs.mask = GPIO_INTEN;
		gc->chip_types[0].regs.ack = GPIO_PORTS_EOI;
		gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
		gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
		gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
		gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
		gc->chip_types[0].chip.irq_set_type = rockchip_irq_set_type;

		irq_set_handler_data(bank->irq, bank);
		irq_set_chained_handler(bank->irq, rockchip_irq_demux);
	}

	return 0;
}

static int rockchip_gpiolib_register(struct platform_device *pdev,
						struct rockchip_pinctrl *info)
{
	struct rockchip_pin_ctrl *ctrl = info->ctrl;
	struct rockchip_pin_bank *bank = ctrl->pin_banks;
	struct gpio_chip *gc;
	int ret;
	int i;

	for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
		if (!bank->valid) {
			dev_warn(&pdev->dev, "bank %s is not valid\n",
				 bank->name);
			continue;
		}

		bank->gpio_chip = rockchip_gpiolib_chip;

		gc = &bank->gpio_chip;
		gc->base = bank->pin_base;
		gc->ngpio = bank->nr_pins;
		gc->dev = &pdev->dev;
		gc->of_node = bank->of_node;
		gc->label = bank->name;

		ret = gpiochip_add(gc);
		if (ret) {
			dev_err(&pdev->dev, "failed to register gpio_chip %s, error code: %d\n",
							gc->label, ret);
			goto fail;
		}
	}

	rockchip_interrupts_register(pdev, info);

	return 0;

fail:
	for (--i, --bank; i >= 0; --i, --bank) {
		if (!bank->valid)
			continue;

		if (gpiochip_remove(&bank->gpio_chip))
			dev_err(&pdev->dev, "gpio chip %s remove failed\n",
							bank->gpio_chip.label);
	}
	return ret;
}

static int rockchip_gpiolib_unregister(struct platform_device *pdev,
						struct rockchip_pinctrl *info)
{
	struct rockchip_pin_ctrl *ctrl = info->ctrl;
	struct rockchip_pin_bank *bank = ctrl->pin_banks;
	int ret = 0;
	int i;

	for (i = 0; !ret && i < ctrl->nr_banks; ++i, ++bank) {
		if (!bank->valid)
			continue;

		ret = gpiochip_remove(&bank->gpio_chip);
	}

	if (ret)
		dev_err(&pdev->dev, "gpio chip remove failed\n");

	return ret;
}

static int rockchip_get_bank_data(struct rockchip_pin_bank *bank,
				  struct device *dev)
{
	struct resource res;

	if (of_address_to_resource(bank->of_node, 0, &res)) {
		dev_err(dev, "cannot find IO resource for bank\n");
		return -ENOENT;
	}

	bank->reg_base = devm_ioremap_resource(dev, &res);
	if (IS_ERR(bank->reg_base))
		return PTR_ERR(bank->reg_base);

	bank->irq = irq_of_parse_and_map(bank->of_node, 0);

	bank->clk = of_clk_get(bank->of_node, 0);
	if (IS_ERR(bank->clk))
		return PTR_ERR(bank->clk);

	return clk_prepare_enable(bank->clk);
}

static const struct of_device_id rockchip_pinctrl_dt_match[];

/* retrieve the soc specific data */
static struct rockchip_pin_ctrl *rockchip_pinctrl_get_soc_data(
						struct rockchip_pinctrl *d,
						struct platform_device *pdev)
{
	const struct of_device_id *match;
	struct device_node *node = pdev->dev.of_node;
	struct device_node *np;
	struct rockchip_pin_ctrl *ctrl;
	struct rockchip_pin_bank *bank;
	int i;

	match = of_match_node(rockchip_pinctrl_dt_match, node);
	ctrl = (struct rockchip_pin_ctrl *)match->data;

	for_each_child_of_node(node, np) {
		if (!of_find_property(np, "gpio-controller", NULL))
			continue;

		bank = ctrl->pin_banks;
		for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
			if (!strcmp(bank->name, np->name)) {
				bank->of_node = np;

				if (!rockchip_get_bank_data(bank, &pdev->dev))
					bank->valid = true;

				break;
			}
		}
	}

	bank = ctrl->pin_banks;
	for (i = 0; i < ctrl->nr_banks; ++i, ++bank) {
		spin_lock_init(&bank->slock);
		bank->drvdata = d;
		bank->pin_base = ctrl->nr_pins;
		ctrl->nr_pins += bank->nr_pins;
	}

	return ctrl;
}

static int rockchip_pinctrl_probe(struct platform_device *pdev)
{
	struct rockchip_pinctrl *info;
	struct device *dev = &pdev->dev;
	struct rockchip_pin_ctrl *ctrl;
	struct resource *res;
	int ret;

	if (!dev->of_node) {
		dev_err(dev, "device tree node not found\n");
		return -ENODEV;
	}

	info = devm_kzalloc(dev, sizeof(struct rockchip_pinctrl), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	ctrl = rockchip_pinctrl_get_soc_data(info, pdev);
	if (!ctrl) {
		dev_err(dev, "driver data not available\n");
		return -EINVAL;
	}
	info->ctrl = ctrl;
	info->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	info->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(info->reg_base))
		return PTR_ERR(info->reg_base);

	ret = rockchip_gpiolib_register(pdev, info);
	if (ret)
		return ret;

	ret = rockchip_pinctrl_register(pdev, info);
	if (ret) {
		rockchip_gpiolib_unregister(pdev, info);
		return ret;
	}

	platform_set_drvdata(pdev, info);

	return 0;
}

static struct rockchip_pin_bank rk2928_pin_banks[] = {
	PIN_BANK(0, 32, "gpio0"),
	PIN_BANK(1, 32, "gpio1"),
	PIN_BANK(2, 32, "gpio2"),
	PIN_BANK(3, 32, "gpio3"),
};

static struct rockchip_pin_ctrl rk2928_pin_ctrl = {
		.pin_banks		= rk2928_pin_banks,
		.nr_banks		= ARRAY_SIZE(rk2928_pin_banks),
		.label			= "RK2928-GPIO",
		.mux_offset		= 0xa8,
		.pull_offset		= 0x118,
		.pull_auto		= 1,
		.pull_bank_stride	= 8,
};

static struct rockchip_pin_bank rk3066a_pin_banks[] = {
	PIN_BANK(0, 32, "gpio0"),
	PIN_BANK(1, 32, "gpio1"),
	PIN_BANK(2, 32, "gpio2"),
	PIN_BANK(3, 32, "gpio3"),
	PIN_BANK(4, 32, "gpio4"),
	PIN_BANK(6, 16, "gpio6"),
};

static struct rockchip_pin_ctrl rk3066a_pin_ctrl = {
		.pin_banks		= rk3066a_pin_banks,
		.nr_banks		= ARRAY_SIZE(rk3066a_pin_banks),
		.label			= "RK3066a-GPIO",
		.mux_offset		= 0xa8,
		.pull_offset		= 0x118,
		.pull_auto		= 1,
		.pull_bank_stride	= 8,
};

static struct rockchip_pin_bank rk3066b_pin_banks[] = {
	PIN_BANK(0, 32, "gpio0"),
	PIN_BANK(1, 32, "gpio1"),
	PIN_BANK(2, 32, "gpio2"),
	PIN_BANK(3, 32, "gpio3"),
};

static struct rockchip_pin_ctrl rk3066b_pin_ctrl = {
		.pin_banks	= rk3066b_pin_banks,
		.nr_banks	= ARRAY_SIZE(rk3066b_pin_banks),
		.label		= "RK3066b-GPIO",
		.mux_offset	= 0x60,
		.pull_offset	= -EINVAL,
};

static struct rockchip_pin_bank rk3188_pin_banks[] = {
	PIN_BANK(0, 32, "gpio0"),
	PIN_BANK(1, 32, "gpio1"),
	PIN_BANK(2, 32, "gpio2"),
	PIN_BANK(3, 32, "gpio3"),
};

static struct rockchip_pin_ctrl rk3188_pin_ctrl = {
		.pin_banks		= rk3188_pin_banks,
		.nr_banks		= ARRAY_SIZE(rk3188_pin_banks),
		.label			= "RK3188-GPIO",
		.mux_offset		= 0x68,
		.pull_offset		= 0x164,
		.pull_bank_stride	= 16,
};

static const struct of_device_id rockchip_pinctrl_dt_match[] = {
	{ .compatible = "rockchip,rk2928-pinctrl",
		.data = (void *)&rk2928_pin_ctrl },
	{ .compatible = "rockchip,rk3066a-pinctrl",
		.data = (void *)&rk3066a_pin_ctrl },
	{ .compatible = "rockchip,rk3066b-pinctrl",
		.data = (void *)&rk3066b_pin_ctrl },
	{ .compatible = "rockchip,rk3188-pinctrl",
		.data = (void *)&rk3188_pin_ctrl },
	{},
};
MODULE_DEVICE_TABLE(of, rockchip_pinctrl_dt_match);

static struct platform_driver rockchip_pinctrl_driver = {
	.probe		= rockchip_pinctrl_probe,
	.driver = {
		.name	= "rockchip-pinctrl",
		.owner	= THIS_MODULE,
		.of_match_table = rockchip_pinctrl_dt_match,
	},
};

static int __init rockchip_pinctrl_drv_register(void)
{
	return platform_driver_register(&rockchip_pinctrl_driver);
}
postcore_initcall(rockchip_pinctrl_drv_register);

MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
MODULE_DESCRIPTION("Rockchip pinctrl driver");
MODULE_LICENSE("GPL v2");