/*
 * Generic device tree based pinctrl driver for one register per pin
 * type pinmux controllers
 *
 * Copyright (C) 2012 Texas Instruments, Inc.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/interrupt.h>

#include <linux/irqchip/chained_irq.h>

#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/pinconf-generic.h>

#include <linux/platform_data/pinctrl-single.h>

#include "core.h"
#include "devicetree.h"
#include "pinconf.h"
#include "pinmux.h"

#define DRIVER_NAME                     "pinctrl-single"
#define PCS_OFF_DISABLED                ~0U

/**
 * struct pcs_func_vals - mux function register offset and value pair
 * @reg:        register virtual address
 * @val:        register value
 * @mask:       mask
 */
struct pcs_func_vals {
        void __iomem *reg;
        unsigned val;
        unsigned mask;
};

/**
 * struct pcs_conf_vals - pinconf parameter, pinconf register offset
 * and value, enable, disable, mask
 * @param:      config parameter
 * @val:        user input bits in the pinconf register
 * @enable:     enable bits in the pinconf register
 * @disable:    disable bits in the pinconf register
 * @mask:       mask bits in the register value
 */
struct pcs_conf_vals {
        enum pin_config_param param;
        unsigned val;
        unsigned enable;
        unsigned disable;
        unsigned mask;
};

/**
 * struct pcs_conf_type - pinconf property name, pinconf param pair
 * @name:       property name in DTS file
 * @param:      config parameter
 */
struct pcs_conf_type {
        const char *name;
        enum pin_config_param param;
};

/**
 * struct pcs_function - pinctrl function
 * @name:       pinctrl function name
 * @vals:       register and vals array
 * @nvals:      number of entries in vals array
 * @pgnames:    array of pingroup names the function uses
 * @npgnames:   number of pingroup names the function uses
 * @conf:       array of pin configurations
 * @nconfs:     number of pin configurations available
 * @node:       list node
 */
struct pcs_function {
        const char *name;
        struct pcs_func_vals *vals;
        unsigned nvals;
        const char **pgnames;
        int npgnames;
        struct pcs_conf_vals *conf;
        int nconfs;
        struct list_head node;
};

/**
 * struct pcs_gpiofunc_range - pin ranges with same mux value of gpio function
 * @offset:     offset base of pins
 * @npins:      number pins with the same mux value of gpio function
 * @gpiofunc:   mux value of gpio function
 * @node:       list node
 */
struct pcs_gpiofunc_range {
        unsigned offset;
        unsigned npins;
        unsigned gpiofunc;
        struct list_head node;
};

/**
 * struct pcs_data - wrapper for data needed by pinctrl framework
 * @pa:         pindesc array
 * @cur:        index to current element
 *
 * REVISIT: We should be able to drop this eventually by adding
 * support for registering pins individually in the pinctrl
 * framework for those drivers that don't need a static array.
 */
struct pcs_data {
        struct pinctrl_pin_desc *pa;
        int cur;
};

/**
 * struct pcs_soc_data - SoC specific settings
 * @flags:      initial SoC specific PCS_FEAT_xxx values
 * @irq:        optional interrupt for the controller
 * @irq_enable_mask:    optional SoC specific interrupt enable mask
 * @irq_status_mask:    optional SoC specific interrupt status mask
 * @rearm:      optional SoC specific wake-up rearm function
 */
struct pcs_soc_data {
        unsigned flags;
        int irq;
        unsigned irq_enable_mask;
        unsigned irq_status_mask;
        void (*rearm)(void);
};

/**
 * struct pcs_device - pinctrl device instance
 * @res:        resources
 * @base:       virtual address of the controller
 * @saved_vals: saved values for the controller
 * @size:       size of the ioremapped area
 * @dev:        device entry
 * @np:         device tree node
 * @pctl:       pin controller device
 * @flags:      mask of PCS_FEAT_xxx values
 * @missing_nr_pinctrl_cells: for legacy binding, may go away
 * @socdata:    soc specific data
 * @lock:       spinlock for register access
 * @mutex:      mutex protecting the lists
 * @width:      bits per mux register
 * @fmask:      function register mask
 * @fshift:     function register shift
 * @foff:       value to turn mux off
 * @fmax:       max number of functions in fmask
 * @bits_per_mux: number of bits per mux
 * @bits_per_pin: number of bits per pin
 * @pins:       physical pins on the SoC
 * @gpiofuncs:  list of gpio functions
 * @irqs:       list of interrupt registers
 * @chip:       chip container for this instance
 * @domain:     IRQ domain for this instance
 * @desc:       pin controller descriptor
 * @read:       register read function to use
 * @write:      register write function to use
 */
struct pcs_device {
        struct resource *res;
        void __iomem *base;
        void *saved_vals;
        unsigned size;
        struct device *dev;
        struct device_node *np;
        struct pinctrl_dev *pctl;
        unsigned flags;
#define PCS_CONTEXT_LOSS_OFF    (1 << 3)
#define PCS_QUIRK_SHARED_IRQ    (1 << 2)
#define PCS_FEAT_IRQ            (1 << 1)
#define PCS_FEAT_PINCONF        (1 << 0)
        struct property *missing_nr_pinctrl_cells;
        struct pcs_soc_data socdata;
        raw_spinlock_t lock;
        struct mutex mutex;
        unsigned width;
        unsigned fmask;
        unsigned fshift;
        unsigned foff;
        unsigned fmax;
        bool bits_per_mux;
        unsigned bits_per_pin;
        struct pcs_data pins;
        struct list_head gpiofuncs;
        struct list_head irqs;
        struct irq_chip chip;
        struct irq_domain *domain;
        struct pinctrl_desc desc;
        unsigned (*read)(void __iomem *reg);
        void (*write)(unsigned val, void __iomem *reg);
};

#define PCS_QUIRK_HAS_SHARED_IRQ        (pcs->flags & PCS_QUIRK_SHARED_IRQ)
#define PCS_HAS_IRQ             (pcs->flags & PCS_FEAT_IRQ)
#define PCS_HAS_PINCONF         (pcs->flags & PCS_FEAT_PINCONF)

static int pcs_pinconf_get(struct pinctrl_dev *pctldev, unsigned pin,
                           unsigned long *config);
static int pcs_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin,
                           unsigned long *configs, unsigned num_configs);

static enum pin_config_param pcs_bias[] = {
        PIN_CONFIG_BIAS_PULL_DOWN,
        PIN_CONFIG_BIAS_PULL_UP,
};

/*
 * This lock class tells lockdep that irqchip core that this single
 * pinctrl can be in a different category than its parents, so it won't
 * report false recursion.
 */
static struct lock_class_key pcs_lock_class;

/* Class for the IRQ request mutex */
static struct lock_class_key pcs_request_class;

/*
 * REVISIT: Reads and writes could eventually use regmap or something
 * generic. But at least on omaps, some mux registers are performance
 * critical as they may need to be remuxed every time before and after
 * idle. Adding tests for register access width for every read and
 * write like regmap is doing is not desired, and caching the registers
 * does not help in this case.
 */

static unsigned __maybe_unused pcs_readb(void __iomem *reg)
{
        return readb(reg);
}

static unsigned __maybe_unused pcs_readw(void __iomem *reg)
{
        return readw(reg);
}

static unsigned __maybe_unused pcs_readl(void __iomem *reg)
{
        return readl(reg);
}

static void __maybe_unused pcs_writeb(unsigned val, void __iomem *reg)
{
        writeb(val, reg);
}

static void __maybe_unused pcs_writew(unsigned val, void __iomem *reg)
{
        writew(val, reg);
}

static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg)
{
        writel(val, reg);
}

static unsigned int pcs_pin_reg_offset_get(struct pcs_device *pcs,
                                           unsigned int pin)
{
        unsigned int mux_bytes = pcs->width / BITS_PER_BYTE;

        if (pcs->bits_per_mux) {
                unsigned int pin_offset_bytes;

                pin_offset_bytes = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
                return (pin_offset_bytes / mux_bytes) * mux_bytes;
        }

        return pin * mux_bytes;
}

static unsigned int pcs_pin_shift_reg_get(struct pcs_device *pcs,
                                          unsigned int pin)
{
        return (pin % (pcs->width / pcs->bits_per_pin)) * pcs->bits_per_pin;
}

static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev,
                                        struct seq_file *s,
                                        unsigned pin)
{
        struct pcs_device *pcs;
        unsigned int val;
        unsigned long offset;
        size_t pa;

        pcs = pinctrl_dev_get_drvdata(pctldev);

        offset = pcs_pin_reg_offset_get(pcs, pin);
        val = pcs->read(pcs->base + offset);

        if (pcs->bits_per_mux)
                val &= pcs->fmask << pcs_pin_shift_reg_get(pcs, pin);

        pa = pcs->res->start + offset;

        seq_printf(s, "%zx %08x %s ", pa, val, DRIVER_NAME);
}

static void pcs_dt_free_map(struct pinctrl_dev *pctldev,
                                struct pinctrl_map *map, unsigned num_maps)
{
        struct pcs_device *pcs;

        pcs = pinctrl_dev_get_drvdata(pctldev);
        devm_kfree(pcs->dev, map);
}

static int pcs_dt_node_to_map(struct pinctrl_dev *pctldev,
                                struct device_node *np_config,
                                struct pinctrl_map **map, unsigned *num_maps);

static const struct pinctrl_ops pcs_pinctrl_ops = {
        .get_groups_count = pinctrl_generic_get_group_count,
        .get_group_name = pinctrl_generic_get_group_name,
        .get_group_pins = pinctrl_generic_get_group_pins,
        .pin_dbg_show = pcs_pin_dbg_show,
        .dt_node_to_map = pcs_dt_node_to_map,
        .dt_free_map = pcs_dt_free_map,
};

static int pcs_get_function(struct pinctrl_dev *pctldev, unsigned pin,
                            struct pcs_function **func)
{
        struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
        struct pin_desc *pdesc = pin_desc_get(pctldev, pin);
        const struct pinctrl_setting_mux *setting;
        struct function_desc *function;
        unsigned fselector;

        /* If pin is not described in DTS & enabled, mux_setting is NULL. */
        setting = pdesc->mux_setting;
        if (!setting)
                return -ENOTSUPP;
        fselector = setting->func;
        function = pinmux_generic_get_function(pctldev, fselector);
        *func = function->data;
        if (!(*func)) {
                dev_err(pcs->dev, "%s could not find function%i\n",
                        __func__, fselector);
                return -ENOTSUPP;
        }
        return 0;
}

static int pcs_set_mux(struct pinctrl_dev *pctldev, unsigned fselector,
        unsigned group)
{
        struct pcs_device *pcs;
        struct function_desc *function;
        struct pcs_function *func;
        int i;

        pcs = pinctrl_dev_get_drvdata(pctldev);
        /* If function mask is null, needn't enable it. */
        if (!pcs->fmask)
                return 0;
        function = pinmux_generic_get_function(pctldev, fselector);
        func = function->data;
        if (!func)
                return -EINVAL;

        dev_dbg(pcs->dev, "enabling %s function%i\n",
                func->name, fselector);

        for (i = 0; i < func->nvals; i++) {
                struct pcs_func_vals *vals;
                unsigned long flags;
                unsigned val, mask;

                vals = &func->vals[i];
                raw_spin_lock_irqsave(&pcs->lock, flags);
                val = pcs->read(vals->reg);

                if (pcs->bits_per_mux)
                        mask = vals->mask;
                else
                        mask = pcs->fmask;

                val &= ~mask;
                val |= (vals->val & mask);
                pcs->write(val, vals->reg);
                raw_spin_unlock_irqrestore(&pcs->lock, flags);
        }

        return 0;
}

static int pcs_request_gpio(struct pinctrl_dev *pctldev,
                            struct pinctrl_gpio_range *range, unsigned pin)
{
        struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
        struct pcs_gpiofunc_range *frange = NULL;
        struct list_head *pos, *tmp;
        unsigned data;

        /* If function mask is null, return directly. */
        if (!pcs->fmask)
                return -ENOTSUPP;

        list_for_each_safe(pos, tmp, &pcs->gpiofuncs) {
                u32 offset;

                frange = list_entry(pos, struct pcs_gpiofunc_range, node);
                if (pin >= frange->offset + frange->npins
                        || pin < frange->offset)
                        continue;

                offset = pcs_pin_reg_offset_get(pcs, pin);

                if (pcs->bits_per_mux) {
                        int pin_shift = pcs_pin_shift_reg_get(pcs, pin);

                        data = pcs->read(pcs->base + offset);
                        data &= ~(pcs->fmask << pin_shift);
                        data |= frange->gpiofunc << pin_shift;
                        pcs->write(data, pcs->base + offset);
                } else {
                        data = pcs->read(pcs->base + offset);
                        data &= ~pcs->fmask;
                        data |= frange->gpiofunc;
                        pcs->write(data, pcs->base + offset);
                }
                break;
        }
        return 0;
}

static const struct pinmux_ops pcs_pinmux_ops = {
        .get_functions_count = pinmux_generic_get_function_count,
        .get_function_name = pinmux_generic_get_function_name,
        .get_function_groups = pinmux_generic_get_function_groups,
        .set_mux = pcs_set_mux,
        .gpio_request_enable = pcs_request_gpio,
};

/* Clear BIAS value */
static void pcs_pinconf_clear_bias(struct pinctrl_dev *pctldev, unsigned pin)
{
        unsigned long config;
        int i;
        for (i = 0; i < ARRAY_SIZE(pcs_bias); i++) {
                config = pinconf_to_config_packed(pcs_bias[i], 0);
                pcs_pinconf_set(pctldev, pin, &config, 1);
        }
}

/*
 * Check whether PIN_CONFIG_BIAS_DISABLE is valid.
 * It's depend on that PULL_DOWN & PULL_UP configs are all invalid.
 */
static bool pcs_pinconf_bias_disable(struct pinctrl_dev *pctldev, unsigned pin)
{
        unsigned long config;
        int i;

        for (i = 0; i < ARRAY_SIZE(pcs_bias); i++) {
                config = pinconf_to_config_packed(pcs_bias[i], 0);
                if (!pcs_pinconf_get(pctldev, pin, &config))
                        goto out;
        }
        return true;
out:
        return false;
}

static int pcs_pinconf_get(struct pinctrl_dev *pctldev,
                                unsigned pin, unsigned long *config)
{
        struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
        struct pcs_function *func;
        enum pin_config_param param;
        unsigned offset = 0, data = 0, i, j, ret;

        ret = pcs_get_function(pctldev, pin, &func);
        if (ret)
                return ret;

        for (i = 0; i < func->nconfs; i++) {
                param = pinconf_to_config_param(*config);
                if (param == PIN_CONFIG_BIAS_DISABLE) {
                        if (pcs_pinconf_bias_disable(pctldev, pin)) {
                                *config = 0;
                                return 0;
                        } else {
                                return -ENOTSUPP;
                        }
                } else if (param != func->conf[i].param) {
                        continue;
                }

                offset = pin * (pcs->width / BITS_PER_BYTE);
                data = pcs->read(pcs->base + offset) & func->conf[i].mask;
                switch (func->conf[i].param) {
                /* 4 parameters */
                case PIN_CONFIG_BIAS_PULL_DOWN:
                case PIN_CONFIG_BIAS_PULL_UP:
                case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
                        if ((data != func->conf[i].enable) ||
                            (data == func->conf[i].disable))
                                return -ENOTSUPP;
                        *config = 0;
                        break;
                /* 2 parameters */
                case PIN_CONFIG_INPUT_SCHMITT:
                        for (j = 0; j < func->nconfs; j++) {
                                switch (func->conf[j].param) {
                                case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
                                        if (data != func->conf[j].enable)
                                                return -ENOTSUPP;
                                        break;
                                default:
                                        break;
                                }
                        }
                        *config = data;
                        break;
                case PIN_CONFIG_DRIVE_STRENGTH:
                case PIN_CONFIG_SLEW_RATE:
                case PIN_CONFIG_MODE_LOW_POWER:
                default:
                        *config = data;
                        break;
                }
                return 0;
        }
        return -ENOTSUPP;
}

static int pcs_pinconf_set(struct pinctrl_dev *pctldev,
                                unsigned pin, unsigned long *configs,
                                unsigned num_configs)
{
        struct pcs_device *pcs = pinctrl_dev_get_drvdata(pctldev);
        struct pcs_function *func;
        unsigned offset = 0, shift = 0, i, data, ret;
        u32 arg;
        int j;

        ret = pcs_get_function(pctldev, pin, &func);
        if (ret)
                return ret;

        for (j = 0; j < num_configs; j++) {
                for (i = 0; i < func->nconfs; i++) {
                        if (pinconf_to_config_param(configs[j])
                                != func->conf[i].param)
                                continue;

                        offset = pin * (pcs->width / BITS_PER_BYTE);
                        data = pcs->read(pcs->base + offset);
                        arg = pinconf_to_config_argument(configs[j]);
                        switch (func->conf[i].param) {
                        /* 2 parameters */
                        case PIN_CONFIG_INPUT_SCHMITT:
                        case PIN_CONFIG_DRIVE_STRENGTH:
                        case PIN_CONFIG_SLEW_RATE:
                        case PIN_CONFIG_MODE_LOW_POWER:
                                shift = ffs(func->conf[i].mask) - 1;
                                data &= ~func->conf[i].mask;
                                data |= (arg << shift) & func->conf[i].mask;
                                break;
                        /* 4 parameters */
                        case PIN_CONFIG_BIAS_DISABLE:
                                pcs_pinconf_clear_bias(pctldev, pin);
                                break;
                        case PIN_CONFIG_BIAS_PULL_DOWN:
                        case PIN_CONFIG_BIAS_PULL_UP:
                                if (arg)
                                        pcs_pinconf_clear_bias(pctldev, pin);
                                fallthrough;
                        case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
                                data &= ~func->conf[i].mask;
                                if (arg)
                                        data |= func->conf[i].enable;
                                else
                                        data |= func->conf[i].disable;
                                break;
                        default:
                                return -ENOTSUPP;
                        }
                        pcs->write(data, pcs->base + offset);

                        break;
                }
                if (i >= func->nconfs)
                        return -ENOTSUPP;
        } /* for each config */

        return 0;
}

static int pcs_pinconf_group_get(struct pinctrl_dev *pctldev,
                                unsigned group, unsigned long *config)
{
        const unsigned *pins;
        unsigned npins, old = 0;
        int i, ret;

        ret = pinctrl_generic_get_group_pins(pctldev, group, &pins, &npins);
        if (ret)
                return ret;
        for (i = 0; i < npins; i++) {
                if (pcs_pinconf_get(pctldev, pins[i], config))
                        return -ENOTSUPP;
                /* configs do not match between two pins */
                if (i && (old != *config))
                        return -ENOTSUPP;
                old = *config;
        }
        return 0;
}

static int pcs_pinconf_group_set(struct pinctrl_dev *pctldev,
                                unsigned group, unsigned long *configs,
                                unsigned num_configs)
{
        const unsigned *pins;
        unsigned npins;
        int i, ret;

        ret = pinctrl_generic_get_group_pins(pctldev, group, &pins, &npins);
        if (ret)
                return ret;
        for (i = 0; i < npins; i++) {
                if (pcs_pinconf_set(pctldev, pins[i], configs, num_configs))
                        return -ENOTSUPP;
        }
        return 0;
}

static void pcs_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                                struct seq_file *s, unsigned pin)
{
}

static void pcs_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
                                struct seq_file *s, unsigned selector)
{
}

static void pcs_pinconf_config_dbg_show(struct pinctrl_dev *pctldev,
                                        struct seq_file *s,
                                        unsigned long config)
{
        pinconf_generic_dump_config(pctldev, s, config);
}

static const struct pinconf_ops pcs_pinconf_ops = {
        .pin_config_get = pcs_pinconf_get,
        .pin_config_set = pcs_pinconf_set,
        .pin_config_group_get = pcs_pinconf_group_get,
        .pin_config_group_set = pcs_pinconf_group_set,
        .pin_config_dbg_show = pcs_pinconf_dbg_show,
        .pin_config_group_dbg_show = pcs_pinconf_group_dbg_show,
        .pin_config_config_dbg_show = pcs_pinconf_config_dbg_show,
        .is_generic = true,
};

/**
 * pcs_add_pin() - add a pin to the static per controller pin array
 * @pcs: pcs driver instance
 * @offset: register offset from base
 */
static int pcs_add_pin(struct pcs_device *pcs, unsigned int offset)
{
        struct pcs_soc_data *pcs_soc = &pcs->socdata;
        struct pinctrl_pin_desc *pin;
        int i;

        i = pcs->pins.cur;
        if (i >= pcs->desc.npins) {
                dev_err(pcs->dev, "too many pins, max %i\n",
                        pcs->desc.npins);
                return -ENOMEM;
        }

        if (pcs_soc->irq_enable_mask) {
                unsigned val;

                val = pcs->read(pcs->base + offset);
                if (val & pcs_soc->irq_enable_mask) {
                        dev_dbg(pcs->dev, "irq enabled at boot for pin at %lx (%x), clearing\n",
                                (unsigned long)pcs->res->start + offset, val);
                        val &= ~pcs_soc->irq_enable_mask;
                        pcs->write(val, pcs->base + offset);
                }
        }

        pin = &pcs->pins.pa[i];
        pin->number = i;
        pcs->pins.cur++;

        return i;
}

/**
 * pcs_allocate_pin_table() - adds all the pins for the pinctrl driver
 * @pcs: pcs driver instance
 *
 * In case of errors, resources are freed in pcs_free_resources.
 *
 * If your hardware needs holes in the address space, then just set
 * up multiple driver instances.
 */
static int pcs_allocate_pin_table(struct pcs_device *pcs)
{
        int mux_bytes, nr_pins, i;

        mux_bytes = pcs->width / BITS_PER_BYTE;

        if (pcs->bits_per_mux) {
                pcs->bits_per_pin = fls(pcs->fmask);
                nr_pins = (pcs->size * BITS_PER_BYTE) / pcs->bits_per_pin;
        } else {
                nr_pins = pcs->size / mux_bytes;
        }

        dev_dbg(pcs->dev, "allocating %i pins\n", nr_pins);
        pcs->pins.pa = devm_kcalloc(pcs->dev,
                                nr_pins, sizeof(*pcs->pins.pa),
                                GFP_KERNEL);
        if (!pcs->pins.pa)
                return -ENOMEM;

        pcs->desc.pins = pcs->pins.pa;
        pcs->desc.npins = nr_pins;

        for (i = 0; i < pcs->desc.npins; i++) {
                unsigned offset;
                int res;

                offset = pcs_pin_reg_offset_get(pcs, i);
                res = pcs_add_pin(pcs, offset);
                if (res < 0) {
                        dev_err(pcs->dev, "error adding pins: %i\n", res);
                        return res;
                }
        }

        return 0;
}

/**
 * pcs_add_function() - adds a new function to the function list
 * @pcs: pcs driver instance
 * @fcn: new function allocated
 * @name: name of the function
 * @vals: array of mux register value pairs used by the function
 * @nvals: number of mux register value pairs
 * @pgnames: array of pingroup names for the function
 * @npgnames: number of pingroup names
 *
 * Caller must take care of locking.
 */
static int pcs_add_function(struct pcs_device *pcs,
                            struct pcs_function **fcn,
                            const char *name,
                            struct pcs_func_vals *vals,
                            unsigned int nvals,
                            const char **pgnames,
                            unsigned int npgnames)
{
        struct pcs_function *function;
        int selector;

        function = devm_kzalloc(pcs->dev, sizeof(*function), GFP_KERNEL);
        if (!function)
                return -ENOMEM;

        function->vals = vals;
        function->nvals = nvals;
        function->name = name;

        selector = pinmux_generic_add_function(pcs->pctl, name,
                                               pgnames, npgnames,
                                               function);
        if (selector < 0) {
                devm_kfree(pcs->dev, function);
                *fcn = NULL;
        } else {
                *fcn = function;
        }

        return selector;
}

/**
 * pcs_get_pin_by_offset() - get a pin index based on the register offset
 * @pcs: pcs driver instance
 * @offset: register offset from the base
 *
 * Note that this is OK as long as the pins are in a static array.
 */
static int pcs_get_pin_by_offset(struct pcs_device *pcs, unsigned offset)
{
        unsigned index;

        if (offset >= pcs->size) {
                dev_err(pcs->dev, "mux offset out of range: 0x%x (0x%x)\n",
                        offset, pcs->size);
                return -EINVAL;
        }

        if (pcs->bits_per_mux)
                index = (offset * BITS_PER_BYTE) / pcs->bits_per_pin;
        else
                index = offset / (pcs->width / BITS_PER_BYTE);

        return index;
}

/*
 * check whether data matches enable bits or disable bits
 * Return value: 1 for matching enable bits, 0 for matching disable bits,
 *               and negative value for matching failure.
 */
static int pcs_config_match(unsigned data, unsigned enable, unsigned disable)
{
        int ret = -EINVAL;

        if (data == enable)
                ret = 1;
        else if (data == disable)
                ret = 0;
        return ret;
}

static void add_config(struct pcs_conf_vals **conf, enum pin_config_param param,
                       unsigned value, unsigned enable, unsigned disable,
                       unsigned mask)
{
        (*conf)->param = param;
        (*conf)->val = value;
        (*conf)->enable = enable;
        (*conf)->disable = disable;
        (*conf)->mask = mask;
        (*conf)++;
}

static void add_setting(unsigned long **setting, enum pin_config_param param,
                        unsigned arg)
{
        **setting = pinconf_to_config_packed(param, arg);
        (*setting)++;
}

/* add pinconf setting with 2 parameters */
static void pcs_add_conf2(struct pcs_device *pcs, struct device_node *np,
                          const char *name, enum pin_config_param param,
                          struct pcs_conf_vals **conf, unsigned long **settings)
{
        unsigned value[2], shift;
        int ret;

        ret = of_property_read_u32_array(np, name, value, 2);
        if (ret)
                return;
        /* set value & mask */
        value[0] &= value[1];
        shift = ffs(value[1]) - 1;
        /* skip enable & disable */
        add_config(conf, param, value[0], 0, 0, value[1]);
        add_setting(settings, param, value[0] >> shift);
}

/* add pinconf setting with 4 parameters */
static void pcs_add_conf4(struct pcs_device *pcs, struct device_node *np,
                          const char *name, enum pin_config_param param,
                          struct pcs_conf_vals **conf, unsigned long **settings)
{
        unsigned value[4];
        int ret;

        /* value to set, enable, disable, mask */
        ret = of_property_read_u32_array(np, name, value, 4);
        if (ret)
                return;
        if (!value[3]) {
                dev_err(pcs->dev, "mask field of the property can't be 0\n");
                return;
        }
        value[0] &= value[3];
        value[1] &= value[3];
        value[2] &= value[3];
        ret = pcs_config_match(value[0], value[1], value[2]);
        if (ret < 0)
                dev_dbg(pcs->dev, "failed to match enable or disable bits\n");
        add_config(conf, param, value[0], value[1], value[2], value[3]);
        add_setting(settings, param, ret);
}

static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np,
                             struct pcs_function *func,
                             struct pinctrl_map **map)

{
        struct pinctrl_map *m = *map;
        int i = 0, nconfs = 0;
        unsigned long *settings = NULL, *s = NULL;
        struct pcs_conf_vals *conf = NULL;
        static const struct pcs_conf_type prop2[] = {
                { "pinctrl-single,drive-strength", PIN_CONFIG_DRIVE_STRENGTH, },
                { "pinctrl-single,slew-rate", PIN_CONFIG_SLEW_RATE, },
                { "pinctrl-single,input-schmitt", PIN_CONFIG_INPUT_SCHMITT, },
                { "pinctrl-single,low-power-mode", PIN_CONFIG_MODE_LOW_POWER, },
        };
        static const struct pcs_conf_type prop4[] = {
                { "pinctrl-single,bias-pullup", PIN_CONFIG_BIAS_PULL_UP, },
                { "pinctrl-single,bias-pulldown", PIN_CONFIG_BIAS_PULL_DOWN, },
                { "pinctrl-single,input-schmitt-enable",
                        PIN_CONFIG_INPUT_SCHMITT_ENABLE, },
        };

        /* If pinconf isn't supported, don't parse properties in below. */
        if (!PCS_HAS_PINCONF)
                return -ENOTSUPP;

        /* cacluate how much properties are supported in current node */
        for (i = 0; i < ARRAY_SIZE(prop2); i++) {
                if (of_find_property(np, prop2[i].name, NULL))
                        nconfs++;
        }
        for (i = 0; i < ARRAY_SIZE(prop4); i++) {
                if (of_find_property(np, prop4[i].name, NULL))
                        nconfs++;
        }
        if (!nconfs)
                return -ENOTSUPP;

        func->conf = devm_kcalloc(pcs->dev,
                                  nconfs, sizeof(struct pcs_conf_vals),
                                  GFP_KERNEL);
        if (!func->conf)
                return -ENOMEM;
        func->nconfs = nconfs;
        conf = &(func->conf[0]);
        m++;
        settings = devm_kcalloc(pcs->dev, nconfs, sizeof(unsigned long),
                                GFP_KERNEL);
        if (!settings)
                return -ENOMEM;
        s = &settings[0];

        for (i = 0; i < ARRAY_SIZE(prop2); i++)
                pcs_add_conf2(pcs, np, prop2[i].name, prop2[i].param,
                              &conf, &s);
        for (i = 0; i < ARRAY_SIZE(prop4); i++)
                pcs_add_conf4(pcs, np, prop4[i].name, prop4[i].param,
                              &conf, &s);
        m->type = PIN_MAP_TYPE_CONFIGS_GROUP;
        m->data.configs.group_or_pin = np->name;
        m->data.configs.configs = settings;
        m->data.configs.num_configs = nconfs;
        return 0;
}

/**
 * pcs_parse_one_pinctrl_entry() - parses a device tree mux entry
 * @pcs: pinctrl driver instance
 * @np: device node of the mux entry
 * @map: map entry
 * @num_maps: number of map
 * @pgnames: pingroup names
 *
 * Note that this binding currently supports only sets of one register + value.
 *
 * Also note that this driver tries to avoid understanding pin and function
 * names because of the extra bloat they would cause especially in the case of
 * a large number of pins. This driver just sets what is specified for the board
 * in the .dts file. Further user space debugging tools can be developed to
 * decipher the pin and function names using debugfs.
 *
 * If you are concerned about the boot time, set up the static pins in
 * the bootloader, and only set up selected pins as device tree entries.
 */
static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
                                                struct device_node *np,
                                                struct pinctrl_map **map,
                                                unsigned *num_maps,
                                                const char **pgnames)
{
        const char *name = "pinctrl-single,pins";
        struct pcs_func_vals *vals;

        int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
        struct pcs_function *function = NULL;

        rows = pinctrl_count_index_with_args(np, name);
        if (rows <= 0) {
                dev_err(pcs->dev, "Invalid number of rows: %d\n", rows);
                return -EINVAL;
        }

        vals = devm_kcalloc(pcs->dev, rows, sizeof(*vals), GFP_KERNEL);
        if (!vals)
                return -ENOMEM;

        pins = devm_kcalloc(pcs->dev, rows, sizeof(*pins), GFP_KERNEL);
        if (!pins)
                goto free_vals;

        for (i = 0; i < rows; i++) {
                struct of_phandle_args pinctrl_spec;
                unsigned int offset;
                int pin;

                res = pinctrl_parse_index_with_args(np, name, i, &pinctrl_spec);
                if (res)
                        return res;

                if (pinctrl_spec.args_count < 2 || pinctrl_spec.args_count > 3) {
                        dev_err(pcs->dev, "invalid args_count for spec: %i\n",
                                pinctrl_spec.args_count);
                        break;
                }

                offset = pinctrl_spec.args[0];
                vals[found].reg = pcs->base + offset;

                switch (pinctrl_spec.args_count) {
                case 2:
                        vals[found].val = pinctrl_spec.args[1];
                        break;
                case 3:
                        vals[found].val = (pinctrl_spec.args[1] | pinctrl_spec.args[2]);
                        break;
                }

                dev_dbg(pcs->dev, "%pOFn index: 0x%x value: 0x%x\n",
                        pinctrl_spec.np, offset, vals[found].val);

                pin = pcs_get_pin_by_offset(pcs, offset);
                if (pin < 0) {
                        dev_err(pcs->dev,
                                "could not add functions for %pOFn %ux\n",
                                np, offset);
                        break;
                }
                pins[found++] = pin;
        }

        pgnames[0] = np->name;
        mutex_lock(&pcs->mutex);
        fsel = pcs_add_function(pcs, &function, np->name, vals, found,
                                pgnames, 1);
        if (fsel < 0) {
                res = fsel;
                goto free_pins;
        }

        gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
        if (gsel < 0) {
                res = gsel;
                goto free_function;
        }

        (*map)->type = PIN_MAP_TYPE_MUX_GROUP;
        (*map)->data.mux.group = np->name;
        (*map)->data.mux.function = np->name;

        if (PCS_HAS_PINCONF && function) {
                res = pcs_parse_pinconf(pcs, np, function, map);
                if (res == 0)
                        *num_maps = 2;
                else if (res == -ENOTSUPP)
                        *num_maps = 1;
                else
                        goto free_pingroups;
        } else {
                *num_maps = 1;
        }
        mutex_unlock(&pcs->mutex);

        return 0;

free_pingroups:
        pinctrl_generic_remove_group(pcs->pctl, gsel);
        *num_maps = 1;
free_function:
        pinmux_generic_remove_function(pcs->pctl, fsel);
free_pins:
        mutex_unlock(&pcs->mutex);
        devm_kfree(pcs->dev, pins);

free_vals:
        devm_kfree(pcs->dev, vals);

        return res;
}

static int pcs_parse_bits_in_pinctrl_entry(struct pcs_device *pcs,
                                                struct device_node *np,
                                                struct pinctrl_map **map,
                                                unsigned *num_maps,
                                                const char **pgnames)
{
        const char *name = "pinctrl-single,bits";
        struct pcs_func_vals *vals;
        int rows, *pins, found = 0, res = -ENOMEM, i, fsel, gsel;
        int npins_in_row;
        struct pcs_function *function = NULL;

        rows = pinctrl_count_index_with_args(np, name);
        if (rows <= 0) {
                dev_err(pcs->dev, "Invalid number of rows: %d\n", rows);
                return -EINVAL;
        }

        npins_in_row = pcs->width / pcs->bits_per_pin;

        vals = devm_kzalloc(pcs->dev,
                            array3_size(rows, npins_in_row, sizeof(*vals)),
                            GFP_KERNEL);
        if (!vals)
                return -ENOMEM;

        pins = devm_kzalloc(pcs->dev,
                            array3_size(rows, npins_in_row, sizeof(*pins)),
                            GFP_KERNEL);
        if (!pins)
                goto free_vals;

        for (i = 0; i < rows; i++) {
                struct of_phandle_args pinctrl_spec;
                unsigned offset, val;
                unsigned mask, bit_pos, val_pos, mask_pos, submask;
                unsigned pin_num_from_lsb;
                int pin;

                res = pinctrl_parse_index_with_args(np, name, i, &pinctrl_spec);
                if (res)
                        return res;

                if (pinctrl_spec.args_count < 3) {
                        dev_err(pcs->dev, "invalid args_count for spec: %i\n",
                                pinctrl_spec.args_count);
                        break;
                }

                /* Index plus two value cells */
                offset = pinctrl_spec.args[0];
                val = pinctrl_spec.args[1];
                mask = pinctrl_spec.args[2];

                dev_dbg(pcs->dev, "%pOFn index: 0x%x value: 0x%x mask: 0x%x\n",
                        pinctrl_spec.np, offset, val, mask);

                /* Parse pins in each row from LSB */
                while (mask) {
                        bit_pos = __ffs(mask);
                        pin_num_from_lsb = bit_pos / pcs->bits_per_pin;
                        mask_pos = ((pcs->fmask) << bit_pos);
                        val_pos = val & mask_pos;
                        submask = mask & mask_pos;

                        if ((mask & mask_pos) == 0) {
                                dev_err(pcs->dev,
                                        "Invalid mask for %pOFn at 0x%x\n",
                                        np, offset);
                                break;
                        }

                        mask &= ~mask_pos;

                        if (submask != mask_pos) {
                                dev_warn(pcs->dev,
                                                "Invalid submask 0x%x for %pOFn at 0x%x\n",
                                                submask, np, offset);
                                continue;
                        }

                        vals[found].mask = submask;
                        vals[found].reg = pcs->base + offset;
                        vals[found].val = val_pos;

                        pin = pcs_get_pin_by_offset(pcs, offset);
                        if (pin < 0) {
                                dev_err(pcs->dev,
                                        "could not add functions for %pOFn %ux\n",
                                        np, offset);
                                break;
                        }
                        pins[found++] = pin + pin_num_from_lsb;
                }
        }

        pgnames[0] = np->name;
        mutex_lock(&pcs->mutex);
        fsel = pcs_add_function(pcs, &function, np->name, vals, found,
                                pgnames, 1);
        if (fsel < 0) {
                res = fsel;
                goto free_pins;
        }

        gsel = pinctrl_generic_add_group(pcs->pctl, np->name, pins, found, pcs);
        if (gsel < 0) {
                res = gsel;
                goto free_function;
        }

        (*map)->type = PIN_MAP_TYPE_MUX_GROUP;
        (*map)->data.mux.group = np->name;
        (*map)->data.mux.function = np->name;

        if (PCS_HAS_PINCONF) {
                dev_err(pcs->dev, "pinconf not supported\n");
                goto free_pingroups;
        }

        *num_maps = 1;
        mutex_unlock(&pcs->mutex);

        return 0;

free_pingroups:
        pinctrl_generic_remove_group(pcs->pctl, gsel);
        *num_maps = 1;
free_function:
        pinmux_generic_remove_function(pcs->pctl, fsel);
free_pins:
        mutex_unlock(&pcs->mutex);
        devm_kfree(pcs->dev, pins);

free_vals:
        devm_kfree(pcs->dev, vals);

        return res;
}
/**
 * pcs_dt_node_to_map() - allocates and parses pinctrl maps
 * @pctldev: pinctrl instance
 * @np_config: device tree pinmux entry
 * @map: array of map entries
 * @num_maps: number of maps
 */
static int pcs_dt_node_to_map(struct pinctrl_dev *pctldev,
                                struct device_node *np_config,
                                struct pinctrl_map **map, unsigned *num_maps)
{
        struct pcs_device *pcs;
        const char **pgnames;
        int ret;

        pcs = pinctrl_dev_get_drvdata(pctldev);

        /* create 2 maps. One is for pinmux, and the other is for pinconf. */
        *map = devm_kcalloc(pcs->dev, 2, sizeof(**map), GFP_KERNEL);
        if (!*map)
                return -ENOMEM;

        *num_maps = 0;

        pgnames = devm_kzalloc(pcs->dev, sizeof(*pgnames), GFP_KERNEL);
        if (!pgnames) {
                ret = -ENOMEM;
                goto free_map;
        }

        if (pcs->bits_per_mux) {
                ret = pcs_parse_bits_in_pinctrl_entry(pcs, np_config, map,
                                num_maps, pgnames);
                if (ret < 0) {
                        dev_err(pcs->dev, "no pins entries for %pOFn\n",
                                np_config);
                        goto free_pgnames;
                }
        } else {
                ret = pcs_parse_one_pinctrl_entry(pcs, np_config, map,
                                num_maps, pgnames);
                if (ret < 0) {
                        dev_err(pcs->dev, "no pins entries for %pOFn\n",
                                np_config);
                        goto free_pgnames;
                }
        }

        return 0;

free_pgnames:
        devm_kfree(pcs->dev, pgnames);
free_map:
        devm_kfree(pcs->dev, *map);

        return ret;
}

/**
 * pcs_irq_free() - free interrupt
 * @pcs: pcs driver instance
 */
static void pcs_irq_free(struct pcs_device *pcs)
{
        struct pcs_soc_data *pcs_soc = &pcs->socdata;

        if (pcs_soc->irq < 0)
                return;

        if (pcs->domain)
                irq_domain_remove(pcs->domain);

        if (PCS_QUIRK_HAS_SHARED_IRQ)
                free_irq(pcs_soc->irq, pcs_soc);
        else
                irq_set_chained_handler(pcs_soc->irq, NULL);
}

/**
 * pcs_free_resources() - free memory used by this driver
 * @pcs: pcs driver instance
 */
static void pcs_free_resources(struct pcs_device *pcs)
{
        pcs_irq_free(pcs);
        pinctrl_unregister(pcs->pctl);

#if IS_BUILTIN(CONFIG_PINCTRL_SINGLE)
        if (pcs->missing_nr_pinctrl_cells)
                of_remove_property(pcs->np, pcs->missing_nr_pinctrl_cells);
#endif
}

static int pcs_add_gpio_func(struct device_node *node, struct pcs_device *pcs)
{
        const char *propname = "pinctrl-single,gpio-range";
        const char *cellname = "#pinctrl-single,gpio-range-cells";
        struct of_phandle_args gpiospec;
        struct pcs_gpiofunc_range *range;
        int ret, i;

        for (i = 0; ; i++) {
                ret = of_parse_phandle_with_args(node, propname, cellname,
                                                 i, &gpiospec);
                /* Do not treat it as error. Only treat it as end condition. */
                if (ret) {
                        ret = 0;
                        break;
                }
                range = devm_kzalloc(pcs->dev, sizeof(*range), GFP_KERNEL);
                if (!range) {
                        ret = -ENOMEM;
                        break;
                }
                range->offset = gpiospec.args[0];
                range->npins = gpiospec.args[1];
                range->gpiofunc = gpiospec.args[2];
                mutex_lock(&pcs->mutex);
                list_add_tail(&range->node, &pcs->gpiofuncs);
                mutex_unlock(&pcs->mutex);
        }
        return ret;
}

/**
 * struct pcs_interrupt
 * @reg:        virtual address of interrupt register
 * @hwirq:      hardware irq number
 * @irq:        virtual irq number
 * @node:       list node
 */
struct pcs_interrupt {
        void __iomem *reg;
        irq_hw_number_t hwirq;
        unsigned int irq;
        struct list_head node;
};

/**
 * pcs_irq_set() - enables or disables an interrupt
 * @pcs_soc: SoC specific settings
 * @irq: interrupt
 * @enable: enable or disable the interrupt
 *
 * Note that this currently assumes one interrupt per pinctrl
 * register that is typically used for wake-up events.
 */
static inline void pcs_irq_set(struct pcs_soc_data *pcs_soc,
                               int irq, const bool enable)
{
        struct pcs_device *pcs;
        struct list_head *pos;
        unsigned mask;

        pcs = container_of(pcs_soc, struct pcs_device, socdata);
        list_for_each(pos, &pcs->irqs) {
                struct pcs_interrupt *pcswi;
                unsigned soc_mask;

                pcswi = list_entry(pos, struct pcs_interrupt, node);
                if (irq != pcswi->irq)
                        continue;

                soc_mask = pcs_soc->irq_enable_mask;
                raw_spin_lock(&pcs->lock);
                mask = pcs->read(pcswi->reg);
                if (enable)
                        mask |= soc_mask;
                else
                        mask &= ~soc_mask;
                pcs->write(mask, pcswi->reg);

                /* flush posted write */
                mask = pcs->read(pcswi->reg);
                raw_spin_unlock(&pcs->lock);
        }

        if (pcs_soc->rearm)
                pcs_soc->rearm();
}

/**
 * pcs_irq_mask() - mask pinctrl interrupt
 * @d: interrupt data
 */
static void pcs_irq_mask(struct irq_data *d)
{
        struct pcs_soc_data *pcs_soc = irq_data_get_irq_chip_data(d);

        pcs_irq_set(pcs_soc, d->irq, false);
}

/**
 * pcs_irq_unmask() - unmask pinctrl interrupt
 * @d: interrupt data
 */
static void pcs_irq_unmask(struct irq_data *d)
{
        struct pcs_soc_data *pcs_soc = irq_data_get_irq_chip_data(d);

        pcs_irq_set(pcs_soc, d->irq, true);
}

/**
 * pcs_irq_set_wake() - toggle the suspend and resume wake up
 * @d: interrupt data
 * @state: wake-up state
 *
 * Note that this should be called only for suspend and resume.
 * For runtime PM, the wake-up events should be enabled by default.
 */
static int pcs_irq_set_wake(struct irq_data *d, unsigned int state)
{
        if (state)
                pcs_irq_unmask(d);
        else
                pcs_irq_mask(d);

        return 0;
}

/**
 * pcs_irq_handle() - common interrupt handler
 * @pcs_soc: SoC specific settings
 *
 * Note that this currently assumes we have one interrupt bit per
 * mux register. This interrupt is typically used for wake-up events.
 * For more complex interrupts different handlers can be specified.
 */
static int pcs_irq_handle(struct pcs_soc_data *pcs_soc)
{
        struct pcs_device *pcs;
        struct list_head *pos;
        int count = 0;

        pcs = container_of(pcs_soc, struct pcs_device, socdata);
        list_for_each(pos, &pcs->irqs) {
                struct pcs_interrupt *pcswi;
                unsigned mask;

                pcswi = list_entry(pos, struct pcs_interrupt, node);
                raw_spin_lock(&pcs->lock);
                mask = pcs->read(pcswi->reg);
                raw_spin_unlock(&pcs->lock);
                if (mask & pcs_soc->irq_status_mask) {
                        generic_handle_irq(irq_find_mapping(pcs->domain,
                                                            pcswi->hwirq));
                        count++;
                }
        }

        return count;
}

/**
 * pcs_irq_handler() - handler for the shared interrupt case
 * @irq: interrupt
 * @d: data
 *
 * Use this for cases where multiple instances of
 * pinctrl-single share a single interrupt like on omaps.
 */
static irqreturn_t pcs_irq_handler(int irq, void *d)
{
        struct pcs_soc_data *pcs_soc = d;

        return pcs_irq_handle(pcs_soc) ? IRQ_HANDLED : IRQ_NONE;
}

/**
 * pcs_irq_handle() - handler for the dedicated chained interrupt case
 * @desc: interrupt descriptor
 *
 * Use this if you have a separate interrupt for each
 * pinctrl-single instance.
 */
static void pcs_irq_chain_handler(struct irq_desc *desc)
{
        struct pcs_soc_data *pcs_soc = irq_desc_get_handler_data(desc);
        struct irq_chip *chip;

        chip = irq_desc_get_chip(desc);
        chained_irq_enter(chip, desc);
        pcs_irq_handle(pcs_soc);
        /* REVISIT: export and add handle_bad_irq(irq, desc)? */
        chained_irq_exit(chip, desc);
}

static int pcs_irqdomain_map(struct irq_domain *d, unsigned int irq,
                             irq_hw_number_t hwirq)
{
        struct pcs_soc_data *pcs_soc = d->host_data;
        struct pcs_device *pcs;
        struct pcs_interrupt *pcswi;

        pcs = container_of(pcs_soc, struct pcs_device, socdata);
        pcswi = devm_kzalloc(pcs->dev, sizeof(*pcswi), GFP_KERNEL);
        if (!pcswi)
                return -ENOMEM;

        pcswi->reg = pcs->base + hwirq;
        pcswi->hwirq = hwirq;
        pcswi->irq = irq;

        mutex_lock(&pcs->mutex);
        list_add_tail(&pcswi->node, &pcs->irqs);
        mutex_unlock(&pcs->mutex);

        irq_set_chip_data(irq, pcs_soc);
        irq_set_chip_and_handler(irq, &pcs->chip,
                                 handle_level_irq);
        irq_set_lockdep_class(irq, &pcs_lock_class, &pcs_request_class);
        irq_set_noprobe(irq);

        return 0;
}

static const struct irq_domain_ops pcs_irqdomain_ops = {
        .map = pcs_irqdomain_map,
        .xlate = irq_domain_xlate_onecell,
};

/**
 * pcs_irq_init_chained_handler() - set up a chained interrupt handler
 * @pcs: pcs driver instance
 * @np: device node pointer
 */
static int pcs_irq_init_chained_handler(struct pcs_device *pcs,
                                        struct device_node *np)
{
        struct pcs_soc_data *pcs_soc = &pcs->socdata;
        const char *name = "pinctrl";
        int num_irqs;

        if (!pcs_soc->irq_enable_mask ||
            !pcs_soc->irq_status_mask) {
                pcs_soc->irq = -1;
                return -EINVAL;
        }

        INIT_LIST_HEAD(&pcs->irqs);
        pcs->chip.name = name;
        pcs->chip.irq_ack = pcs_irq_mask;
        pcs->chip.irq_mask = pcs_irq_mask;
        pcs->chip.irq_unmask = pcs_irq_unmask;
        pcs->chip.irq_set_wake = pcs_irq_set_wake;

        if (PCS_QUIRK_HAS_SHARED_IRQ) {
                int res;

                res = request_irq(pcs_soc->irq, pcs_irq_handler,
                                  IRQF_SHARED | IRQF_NO_SUSPEND |
                                  IRQF_NO_THREAD,
                                  name, pcs_soc);
                if (res) {
                        pcs_soc->irq = -1;
                        return res;
                }
        } else {
                irq_set_chained_handler_and_data(pcs_soc->irq,
                                                 pcs_irq_chain_handler,
                                                 pcs_soc);
        }

        /*
         * We can use the register offset as the hardirq
         * number as irq_domain_add_simple maps them lazily.
         * This way we can easily support more than one
         * interrupt per function if needed.
         */
        num_irqs = pcs->size;

        pcs->domain = irq_domain_add_simple(np, num_irqs, 0,
                                            &pcs_irqdomain_ops,
                                            pcs_soc);
        if (!pcs->domain) {
                irq_set_chained_handler(pcs_soc->irq, NULL);
                return -EINVAL;
        }

        return 0;
}

#ifdef CONFIG_PM
static int pcs_save_context(struct pcs_device *pcs)
{
        int i, mux_bytes;
        u64 *regsl;
        u32 *regsw;
        u16 *regshw;

        mux_bytes = pcs->width / BITS_PER_BYTE;

        if (!pcs->saved_vals) {
                pcs->saved_vals = devm_kzalloc(pcs->dev, pcs->size, GFP_ATOMIC);
                if (!pcs->saved_vals)
                        return -ENOMEM;
        }

        switch (pcs->width) {
        case 64:
                regsl = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        *regsl++ = pcs->read(pcs->base + i);
                break;
        case 32:
                regsw = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        *regsw++ = pcs->read(pcs->base + i);
                break;
        case 16:
                regshw = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        *regshw++ = pcs->read(pcs->base + i);
                break;
        }

        return 0;
}

static void pcs_restore_context(struct pcs_device *pcs)
{
        int i, mux_bytes;
        u64 *regsl;
        u32 *regsw;
        u16 *regshw;

        mux_bytes = pcs->width / BITS_PER_BYTE;

        switch (pcs->width) {
        case 64:
                regsl = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        pcs->write(*regsl++, pcs->base + i);
                break;
        case 32:
                regsw = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        pcs->write(*regsw++, pcs->base + i);
                break;
        case 16:
                regshw = pcs->saved_vals;
                for (i = 0; i < pcs->size; i += mux_bytes)
                        pcs->write(*regshw++, pcs->base + i);
                break;
        }
}

static int pinctrl_single_suspend(struct platform_device *pdev,
                                        pm_message_t state)
{
        struct pcs_device *pcs;

        pcs = platform_get_drvdata(pdev);
        if (!pcs)
                return -EINVAL;

        if (pcs->flags & PCS_CONTEXT_LOSS_OFF) {
                int ret;

                ret = pcs_save_context(pcs);
                if (ret < 0)
                        return ret;
        }

        return pinctrl_force_sleep(pcs->pctl);
}

static int pinctrl_single_resume(struct platform_device *pdev)
{
        struct pcs_device *pcs;

        pcs = platform_get_drvdata(pdev);
        if (!pcs)
                return -EINVAL;

        if (pcs->flags & PCS_CONTEXT_LOSS_OFF)
                pcs_restore_context(pcs);

        return pinctrl_force_default(pcs->pctl);
}
#endif

/**
 * pcs_quirk_missing_pinctrl_cells - handle legacy binding
 * @pcs: pinctrl driver instance
 * @np: device tree node
 * @cells: number of cells
 *
 * Handle legacy binding with no #pinctrl-cells. This should be
 * always two pinctrl-single,bit-per-mux and one for others.
 * At some point we may want to consider removing this.
 */
static int pcs_quirk_missing_pinctrl_cells(struct pcs_device *pcs,
                                           struct device_node *np,
                                           int cells)
{
        struct property *p;
        const char *name = "#pinctrl-cells";
        int error;
        u32 val;

        error = of_property_read_u32(np, name, &val);
        if (!error)
                return 0;

        dev_warn(pcs->dev, "please update dts to use %s = <%i>\n",
                 name, cells);

        p = devm_kzalloc(pcs->dev, sizeof(*p), GFP_KERNEL);
        if (!p)
                return -ENOMEM;

        p->length = sizeof(__be32);
        p->value = devm_kzalloc(pcs->dev, sizeof(__be32), GFP_KERNEL);
        if (!p->value)
                return -ENOMEM;
        *(__be32 *)p->value = cpu_to_be32(cells);

        p->name = devm_kstrdup(pcs->dev, name, GFP_KERNEL);
        if (!p->name)
                return -ENOMEM;

        pcs->missing_nr_pinctrl_cells = p;

#if IS_BUILTIN(CONFIG_PINCTRL_SINGLE)
        error = of_add_property(np, pcs->missing_nr_pinctrl_cells);
#endif

        return error;
}

static int pcs_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct pcs_pdata *pdata;
        struct resource *res;
        struct pcs_device *pcs;
        const struct pcs_soc_data *soc;
        int ret;

        soc = of_device_get_match_data(&pdev->dev);
        if (WARN_ON(!soc))
                return -EINVAL;

        pcs = devm_kzalloc(&pdev->dev, sizeof(*pcs), GFP_KERNEL);
        if (!pcs)
                return -ENOMEM;

        pcs->dev = &pdev->dev;
        pcs->np = np;
        raw_spin_lock_init(&pcs->lock);
        mutex_init(&pcs->mutex);
        INIT_LIST_HEAD(&pcs->gpiofuncs);
        pcs->flags = soc->flags;
        memcpy(&pcs->socdata, soc, sizeof(*soc));

        ret = of_property_read_u32(np, "pinctrl-single,register-width",
                                   &pcs->width);
        if (ret) {
                dev_err(pcs->dev, "register width not specified\n");

                return ret;
        }

        ret = of_property_read_u32(np, "pinctrl-single,function-mask",
                                   &pcs->fmask);
        if (!ret) {
                pcs->fshift = __ffs(pcs->fmask);
                pcs->fmax = pcs->fmask >> pcs->fshift;
        } else {
                /* If mask property doesn't exist, function mux is invalid. */
                pcs->fmask = 0;
                pcs->fshift = 0;
                pcs->fmax = 0;
        }

        ret = of_property_read_u32(np, "pinctrl-single,function-off",
                                        &pcs->foff);
        if (ret)
                pcs->foff = PCS_OFF_DISABLED;

        pcs->bits_per_mux = of_property_read_bool(np,
                                                  "pinctrl-single,bit-per-mux");
        ret = pcs_quirk_missing_pinctrl_cells(pcs, np,
                                              pcs->bits_per_mux ? 2 : 1);
        if (ret) {
                dev_err(&pdev->dev, "unable to patch #pinctrl-cells\n");

                return ret;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(pcs->dev, "could not get resource\n");
                return -ENODEV;
        }

        pcs->res = devm_request_mem_region(pcs->dev, res->start,
                        resource_size(res), DRIVER_NAME);
        if (!pcs->res) {
                dev_err(pcs->dev, "could not get mem_region\n");
                return -EBUSY;
        }

        pcs->size = resource_size(pcs->res);
        pcs->base = devm_ioremap(pcs->dev, pcs->res->start, pcs->size);
        if (!pcs->base) {
                dev_err(pcs->dev, "could not ioremap\n");
                return -ENODEV;
        }

        platform_set_drvdata(pdev, pcs);

        switch (pcs->width) {
        case 8:
                pcs->read = pcs_readb;
                pcs->write = pcs_writeb;
                break;
        case 16:
                pcs->read = pcs_readw;
                pcs->write = pcs_writew;
                break;
        case 32:
                pcs->read = pcs_readl;
                pcs->write = pcs_writel;
                break;
        default:
                break;
        }

        pcs->desc.name = DRIVER_NAME;
        pcs->desc.pctlops = &pcs_pinctrl_ops;
        pcs->desc.pmxops = &pcs_pinmux_ops;
        if (PCS_HAS_PINCONF)
                pcs->desc.confops = &pcs_pinconf_ops;
        pcs->desc.owner = THIS_MODULE;

        ret = pcs_allocate_pin_table(pcs);
        if (ret < 0)
                goto free;

        ret = pinctrl_register_and_init(&pcs->desc, pcs->dev, pcs, &pcs->pctl);
        if (ret) {
                dev_err(pcs->dev, "could not register single pinctrl driver\n");
                goto free;
        }

        ret = pcs_add_gpio_func(np, pcs);
        if (ret < 0)
                goto free;

        pcs->socdata.irq = irq_of_parse_and_map(np, 0);
        if (pcs->socdata.irq)
                pcs->flags |= PCS_FEAT_IRQ;

        /* We still need auxdata for some omaps for PRM interrupts */
        pdata = dev_get_platdata(&pdev->dev);
        if (pdata) {
                if (pdata->rearm)
                        pcs->socdata.rearm = pdata->rearm;
                if (pdata->irq) {
                        pcs->socdata.irq = pdata->irq;
                        pcs->flags |= PCS_FEAT_IRQ;
                }
        }

        if (PCS_HAS_IRQ) {
                ret = pcs_irq_init_chained_handler(pcs, np);
                if (ret < 0)
                        dev_warn(pcs->dev, "initialized with no interrupts\n");
        }

        dev_info(pcs->dev, "%i pins, size %u\n", pcs->desc.npins, pcs->size);

        return pinctrl_enable(pcs->pctl);

free:
        pcs_free_resources(pcs);

        return ret;
}

static int pcs_remove(struct platform_device *pdev)
{
        struct pcs_device *pcs = platform_get_drvdata(pdev);

        if (!pcs)
                return 0;

        pcs_free_resources(pcs);

        return 0;
}

static const struct pcs_soc_data pinctrl_single_omap_wkup = {
        .flags = PCS_QUIRK_SHARED_IRQ,
        .irq_enable_mask = (1 << 14),   /* OMAP_WAKEUP_EN */
        .irq_status_mask = (1 << 15),   /* OMAP_WAKEUP_EVENT */
};

static const struct pcs_soc_data pinctrl_single_dra7 = {
        .irq_enable_mask = (1 << 24),   /* WAKEUPENABLE */
        .irq_status_mask = (1 << 25),   /* WAKEUPEVENT */
};

static const struct pcs_soc_data pinctrl_single_am437x = {
        .flags = PCS_QUIRK_SHARED_IRQ | PCS_CONTEXT_LOSS_OFF,
        .irq_enable_mask = (1 << 29),   /* OMAP_WAKEUP_EN */
        .irq_status_mask = (1 << 30),   /* OMAP_WAKEUP_EVENT */
};

static const struct pcs_soc_data pinctrl_single = {
};

static const struct pcs_soc_data pinconf_single = {
        .flags = PCS_FEAT_PINCONF,
};

static const struct of_device_id pcs_of_match[] = {
        { .compatible = "ti,omap3-padconf", .data = &pinctrl_single_omap_wkup },
        { .compatible = "ti,omap4-padconf", .data = &pinctrl_single_omap_wkup },
        { .compatible = "ti,omap5-padconf", .data = &pinctrl_single_omap_wkup },
        { .compatible = "ti,dra7-padconf", .data = &pinctrl_single_dra7 },
        { .compatible = "ti,am437-padconf", .data = &pinctrl_single_am437x },
        { .compatible = "pinctrl-single", .data = &pinctrl_single },
        { .compatible = "pinconf-single", .data = &pinconf_single },
        { },
};
MODULE_DEVICE_TABLE(of, pcs_of_match);

static struct platform_driver pcs_driver = {
        .probe          = pcs_probe,
        .remove         = pcs_remove,
        .driver = {
                .name           = DRIVER_NAME,
                .of_match_table = pcs_of_match,
        },
#ifdef CONFIG_PM
        .suspend = pinctrl_single_suspend,
        .resume = pinctrl_single_resume,
#endif
};

module_platform_driver(pcs_driver);

MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
MODULE_DESCRIPTION("One-register-per-pin type device tree based pinctrl driver");
MODULE_LICENSE("GPL v2");