/*
 * Intel pinctrl/GPIO core driver.
 *
 * Copyright (C) 2015, Intel Corporation
 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.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.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/gpio/driver.h>
#include <linux/log2.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinconf-generic.h>

#include "../core.h"
#include "pinctrl-intel.h"

/* Offset from regs */
#define REVID                           0x000
#define REVID_SHIFT                     16
#define REVID_MASK                      GENMASK(31, 16)

#define PADBAR                          0x00c
#define GPI_IS                          0x100
#define GPI_GPE_STS                     0x140
#define GPI_GPE_EN                      0x160

#define PADOWN_BITS                     4
#define PADOWN_SHIFT(p)                 ((p) % 8 * PADOWN_BITS)
#define PADOWN_MASK(p)                  (0xf << PADOWN_SHIFT(p))
#define PADOWN_GPP(p)                   ((p) / 8)

/* Offset from pad_regs */
#define PADCFG0                         0x000
#define PADCFG0_RXEVCFG_SHIFT           25
#define PADCFG0_RXEVCFG_MASK            (3 << PADCFG0_RXEVCFG_SHIFT)
#define PADCFG0_RXEVCFG_LEVEL           0
#define PADCFG0_RXEVCFG_EDGE            1
#define PADCFG0_RXEVCFG_DISABLED        2
#define PADCFG0_RXEVCFG_EDGE_BOTH       3
#define PADCFG0_PREGFRXSEL              BIT(24)
#define PADCFG0_RXINV                   BIT(23)
#define PADCFG0_GPIROUTIOXAPIC          BIT(20)
#define PADCFG0_GPIROUTSCI              BIT(19)
#define PADCFG0_GPIROUTSMI              BIT(18)
#define PADCFG0_GPIROUTNMI              BIT(17)
#define PADCFG0_PMODE_SHIFT             10
#define PADCFG0_PMODE_MASK              (0xf << PADCFG0_PMODE_SHIFT)
#define PADCFG0_GPIORXDIS               BIT(9)
#define PADCFG0_GPIOTXDIS               BIT(8)
#define PADCFG0_GPIORXSTATE             BIT(1)
#define PADCFG0_GPIOTXSTATE             BIT(0)

#define PADCFG1                         0x004
#define PADCFG1_TERM_UP                 BIT(13)
#define PADCFG1_TERM_SHIFT              10
#define PADCFG1_TERM_MASK               (7 << PADCFG1_TERM_SHIFT)
#define PADCFG1_TERM_20K                4
#define PADCFG1_TERM_2K                 3
#define PADCFG1_TERM_5K                 2
#define PADCFG1_TERM_1K                 1

#define PADCFG2                         0x008
#define PADCFG2_DEBEN                   BIT(0)
#define PADCFG2_DEBOUNCE_SHIFT          1
#define PADCFG2_DEBOUNCE_MASK           GENMASK(4, 1)

#define DEBOUNCE_PERIOD                 31250 /* ns */

struct intel_pad_context {
        u32 padcfg0;
        u32 padcfg1;
        u32 padcfg2;
};

struct intel_community_context {
        u32 *intmask;
};

struct intel_pinctrl_context {
        struct intel_pad_context *pads;
        struct intel_community_context *communities;
};

/**
 * struct intel_pinctrl - Intel pinctrl private structure
 * @dev: Pointer to the device structure
 * @lock: Lock to serialize register access
 * @pctldesc: Pin controller description
 * @pctldev: Pointer to the pin controller device
 * @chip: GPIO chip in this pin controller
 * @soc: SoC/PCH specific pin configuration data
 * @communities: All communities in this pin controller
 * @ncommunities: Number of communities in this pin controller
 * @context: Configuration saved over system sleep
 * @irq: pinctrl/GPIO chip irq number
 */
struct intel_pinctrl {
        struct device *dev;
        raw_spinlock_t lock;
        struct pinctrl_desc pctldesc;
        struct pinctrl_dev *pctldev;
        struct gpio_chip chip;
        const struct intel_pinctrl_soc_data *soc;
        struct intel_community *communities;
        size_t ncommunities;
        struct intel_pinctrl_context context;
        int irq;
};

#define pin_to_padno(c, p)      ((p) - (c)->pin_base)
#define padgroup_offset(g, p)   ((p) - (g)->base)

static struct intel_community *intel_get_community(struct intel_pinctrl *pctrl,
                                                   unsigned pin)
{
        struct intel_community *community;
        int i;

        for (i = 0; i < pctrl->ncommunities; i++) {
                community = &pctrl->communities[i];
                if (pin >= community->pin_base &&
                    pin < community->pin_base + community->npins)
                        return community;
        }

        dev_warn(pctrl->dev, "failed to find community for pin %u\n", pin);
        return NULL;
}

static const struct intel_padgroup *
intel_community_get_padgroup(const struct intel_community *community,
                             unsigned pin)
{
        int i;

        for (i = 0; i < community->ngpps; i++) {
                const struct intel_padgroup *padgrp = &community->gpps[i];

                if (pin >= padgrp->base && pin < padgrp->base + padgrp->size)
                        return padgrp;
        }

        return NULL;
}

static void __iomem *intel_get_padcfg(struct intel_pinctrl *pctrl, unsigned pin,
                                      unsigned reg)
{
        const struct intel_community *community;
        unsigned padno;
        size_t nregs;

        community = intel_get_community(pctrl, pin);
        if (!community)
                return NULL;

        padno = pin_to_padno(community, pin);
        nregs = (community->features & PINCTRL_FEATURE_DEBOUNCE) ? 4 : 2;

        if (reg == PADCFG2 && !(community->features & PINCTRL_FEATURE_DEBOUNCE))
                return NULL;

        return community->pad_regs + reg + padno * nregs * 4;
}

static bool intel_pad_owned_by_host(struct intel_pinctrl *pctrl, unsigned pin)
{
        const struct intel_community *community;
        const struct intel_padgroup *padgrp;
        unsigned gpp, offset, gpp_offset;
        void __iomem *padown;

        community = intel_get_community(pctrl, pin);
        if (!community)
                return false;
        if (!community->padown_offset)
                return true;

        padgrp = intel_community_get_padgroup(community, pin);
        if (!padgrp)
                return false;

        gpp_offset = padgroup_offset(padgrp, pin);
        gpp = PADOWN_GPP(gpp_offset);
        offset = community->padown_offset + padgrp->padown_num * 4 + gpp * 4;
        padown = community->regs + offset;

        return !(readl(padown) & PADOWN_MASK(gpp_offset));
}

static bool intel_pad_acpi_mode(struct intel_pinctrl *pctrl, unsigned pin)
{
        const struct intel_community *community;
        const struct intel_padgroup *padgrp;
        unsigned offset, gpp_offset;
        void __iomem *hostown;

        community = intel_get_community(pctrl, pin);
        if (!community)
                return true;
        if (!community->hostown_offset)
                return false;

        padgrp = intel_community_get_padgroup(community, pin);
        if (!padgrp)
                return true;

        gpp_offset = padgroup_offset(padgrp, pin);
        offset = community->hostown_offset + padgrp->reg_num * 4;
        hostown = community->regs + offset;

        return !(readl(hostown) & BIT(gpp_offset));
}

static bool intel_pad_locked(struct intel_pinctrl *pctrl, unsigned pin)
{
        struct intel_community *community;
        const struct intel_padgroup *padgrp;
        unsigned offset, gpp_offset;
        u32 value;

        community = intel_get_community(pctrl, pin);
        if (!community)
                return true;
        if (!community->padcfglock_offset)
                return false;

        padgrp = intel_community_get_padgroup(community, pin);
        if (!padgrp)
                return true;

        gpp_offset = padgroup_offset(padgrp, pin);

        /*
         * If PADCFGLOCK and PADCFGLOCKTX bits are both clear for this pad,
         * the pad is considered unlocked. Any other case means that it is
         * either fully or partially locked and we don't touch it.
         */
        offset = community->padcfglock_offset + padgrp->reg_num * 8;
        value = readl(community->regs + offset);
        if (value & BIT(gpp_offset))
                return true;

        offset = community->padcfglock_offset + 4 + padgrp->reg_num * 8;
        value = readl(community->regs + offset);
        if (value & BIT(gpp_offset))
                return true;

        return false;
}

static bool intel_pad_usable(struct intel_pinctrl *pctrl, unsigned pin)
{
        return intel_pad_owned_by_host(pctrl, pin) &&
                !intel_pad_locked(pctrl, pin);
}

static int intel_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->soc->ngroups;
}

static const char *intel_get_group_name(struct pinctrl_dev *pctldev,
                                      unsigned group)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->soc->groups[group].name;
}

static int intel_get_group_pins(struct pinctrl_dev *pctldev, unsigned group,
                              const unsigned **pins, unsigned *npins)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        *pins = pctrl->soc->groups[group].pins;
        *npins = pctrl->soc->groups[group].npins;
        return 0;
}

static void intel_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
                               unsigned pin)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        void __iomem *padcfg;
        u32 cfg0, cfg1, mode;
        bool locked, acpi;

        if (!intel_pad_owned_by_host(pctrl, pin)) {
                seq_puts(s, "not available");
                return;
        }

        cfg0 = readl(intel_get_padcfg(pctrl, pin, PADCFG0));
        cfg1 = readl(intel_get_padcfg(pctrl, pin, PADCFG1));

        mode = (cfg0 & PADCFG0_PMODE_MASK) >> PADCFG0_PMODE_SHIFT;
        if (!mode)
                seq_puts(s, "GPIO ");
        else
                seq_printf(s, "mode %d ", mode);

        seq_printf(s, "0x%08x 0x%08x", cfg0, cfg1);

        /* Dump the additional PADCFG registers if available */
        padcfg = intel_get_padcfg(pctrl, pin, PADCFG2);
        if (padcfg)
                seq_printf(s, " 0x%08x", readl(padcfg));

        locked = intel_pad_locked(pctrl, pin);
        acpi = intel_pad_acpi_mode(pctrl, pin);

        if (locked || acpi) {
                seq_puts(s, " [");
                if (locked) {
                        seq_puts(s, "LOCKED");
                        if (acpi)
                                seq_puts(s, ", ");
                }
                if (acpi)
                        seq_puts(s, "ACPI");
                seq_puts(s, "]");
        }
}

static const struct pinctrl_ops intel_pinctrl_ops = {
        .get_groups_count = intel_get_groups_count,
        .get_group_name = intel_get_group_name,
        .get_group_pins = intel_get_group_pins,
        .pin_dbg_show = intel_pin_dbg_show,
};

static int intel_get_functions_count(struct pinctrl_dev *pctldev)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->soc->nfunctions;
}

static const char *intel_get_function_name(struct pinctrl_dev *pctldev,
                                           unsigned function)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        return pctrl->soc->functions[function].name;
}

static int intel_get_function_groups(struct pinctrl_dev *pctldev,
                                     unsigned function,
                                     const char * const **groups,
                                     unsigned * const ngroups)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

        *groups = pctrl->soc->functions[function].groups;
        *ngroups = pctrl->soc->functions[function].ngroups;
        return 0;
}

static int intel_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned function,
                                unsigned group)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        const struct intel_pingroup *grp = &pctrl->soc->groups[group];
        unsigned long flags;
        int i;

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        /*
         * All pins in the groups needs to be accessible and writable
         * before we can enable the mux for this group.
         */
        for (i = 0; i < grp->npins; i++) {
                if (!intel_pad_usable(pctrl, grp->pins[i])) {
                        raw_spin_unlock_irqrestore(&pctrl->lock, flags);
                        return -EBUSY;
                }
        }

        /* Now enable the mux setting for each pin in the group */
        for (i = 0; i < grp->npins; i++) {
                void __iomem *padcfg0;
                u32 value;

                padcfg0 = intel_get_padcfg(pctrl, grp->pins[i], PADCFG0);
                value = readl(padcfg0);

                value &= ~PADCFG0_PMODE_MASK;

                if (grp->modes)
                        value |= grp->modes[i] << PADCFG0_PMODE_SHIFT;
                else
                        value |= grp->mode << PADCFG0_PMODE_SHIFT;

                writel(value, padcfg0);
        }

        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return 0;
}

static void __intel_gpio_set_direction(void __iomem *padcfg0, bool input)
{
        u32 value;

        value = readl(padcfg0);
        if (input) {
                value &= ~PADCFG0_GPIORXDIS;
                value |= PADCFG0_GPIOTXDIS;
        } else {
                value &= ~PADCFG0_GPIOTXDIS;
                value |= PADCFG0_GPIORXDIS;
        }
        writel(value, padcfg0);
}

static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
                                     struct pinctrl_gpio_range *range,
                                     unsigned pin)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        void __iomem *padcfg0;
        unsigned long flags;
        u32 value;

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        if (!intel_pad_usable(pctrl, pin)) {
                raw_spin_unlock_irqrestore(&pctrl->lock, flags);
                return -EBUSY;
        }

        padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
        /* Put the pad into GPIO mode */
        value = readl(padcfg0) & ~PADCFG0_PMODE_MASK;
        /* Disable SCI/SMI/NMI generation */
        value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);
        value &= ~(PADCFG0_GPIROUTSMI | PADCFG0_GPIROUTNMI);
        writel(value, padcfg0);

        /* Disable TX buffer and enable RX (this will be input) */
        __intel_gpio_set_direction(padcfg0, true);

        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return 0;
}

static int intel_gpio_set_direction(struct pinctrl_dev *pctldev,
                                    struct pinctrl_gpio_range *range,
                                    unsigned pin, bool input)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        void __iomem *padcfg0;
        unsigned long flags;

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
        __intel_gpio_set_direction(padcfg0, input);

        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return 0;
}

static const struct pinmux_ops intel_pinmux_ops = {
        .get_functions_count = intel_get_functions_count,
        .get_function_name = intel_get_function_name,
        .get_function_groups = intel_get_function_groups,
        .set_mux = intel_pinmux_set_mux,
        .gpio_request_enable = intel_gpio_request_enable,
        .gpio_set_direction = intel_gpio_set_direction,
};

static int intel_config_get(struct pinctrl_dev *pctldev, unsigned pin,
                            unsigned long *config)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param param = pinconf_to_config_param(*config);
        const struct intel_community *community;
        u32 value, term;
        u32 arg = 0;

        if (!intel_pad_owned_by_host(pctrl, pin))
                return -ENOTSUPP;

        community = intel_get_community(pctrl, pin);
        value = readl(intel_get_padcfg(pctrl, pin, PADCFG1));
        term = (value & PADCFG1_TERM_MASK) >> PADCFG1_TERM_SHIFT;

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
                if (term)
                        return -EINVAL;
                break;

        case PIN_CONFIG_BIAS_PULL_UP:
                if (!term || !(value & PADCFG1_TERM_UP))
                        return -EINVAL;

                switch (term) {
                case PADCFG1_TERM_1K:
                        arg = 1000;
                        break;
                case PADCFG1_TERM_2K:
                        arg = 2000;
                        break;
                case PADCFG1_TERM_5K:
                        arg = 5000;
                        break;
                case PADCFG1_TERM_20K:
                        arg = 20000;
                        break;
                }

                break;

        case PIN_CONFIG_BIAS_PULL_DOWN:
                if (!term || value & PADCFG1_TERM_UP)
                        return -EINVAL;

                switch (term) {
                case PADCFG1_TERM_1K:
                        if (!(community->features & PINCTRL_FEATURE_1K_PD))
                                return -EINVAL;
                        arg = 1000;
                        break;
                case PADCFG1_TERM_5K:
                        arg = 5000;
                        break;
                case PADCFG1_TERM_20K:
                        arg = 20000;
                        break;
                }

                break;

        case PIN_CONFIG_INPUT_DEBOUNCE: {
                void __iomem *padcfg2;
                u32 v;

                padcfg2 = intel_get_padcfg(pctrl, pin, PADCFG2);
                if (!padcfg2)
                        return -ENOTSUPP;

                v = readl(padcfg2);
                if (!(v & PADCFG2_DEBEN))
                        return -EINVAL;

                v = (v & PADCFG2_DEBOUNCE_MASK) >> PADCFG2_DEBOUNCE_SHIFT;
                arg = BIT(v) * DEBOUNCE_PERIOD / 1000;

                break;
        }

        default:
                return -ENOTSUPP;
        }

        *config = pinconf_to_config_packed(param, arg);
        return 0;
}

static int intel_config_set_pull(struct intel_pinctrl *pctrl, unsigned pin,
                                 unsigned long config)
{
        unsigned param = pinconf_to_config_param(config);
        unsigned arg = pinconf_to_config_argument(config);
        const struct intel_community *community;
        void __iomem *padcfg1;
        unsigned long flags;
        int ret = 0;
        u32 value;

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        community = intel_get_community(pctrl, pin);
        padcfg1 = intel_get_padcfg(pctrl, pin, PADCFG1);
        value = readl(padcfg1);

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
                value &= ~(PADCFG1_TERM_MASK | PADCFG1_TERM_UP);
                break;

        case PIN_CONFIG_BIAS_PULL_UP:
                value &= ~PADCFG1_TERM_MASK;

                value |= PADCFG1_TERM_UP;

                switch (arg) {
                case 20000:
                        value |= PADCFG1_TERM_20K << PADCFG1_TERM_SHIFT;
                        break;
                case 5000:
                        value |= PADCFG1_TERM_5K << PADCFG1_TERM_SHIFT;
                        break;
                case 2000:
                        value |= PADCFG1_TERM_2K << PADCFG1_TERM_SHIFT;
                        break;
                case 1000:
                        value |= PADCFG1_TERM_1K << PADCFG1_TERM_SHIFT;
                        break;
                default:
                        ret = -EINVAL;
                }

                break;

        case PIN_CONFIG_BIAS_PULL_DOWN:
                value &= ~(PADCFG1_TERM_UP | PADCFG1_TERM_MASK);

                switch (arg) {
                case 20000:
                        value |= PADCFG1_TERM_20K << PADCFG1_TERM_SHIFT;
                        break;
                case 5000:
                        value |= PADCFG1_TERM_5K << PADCFG1_TERM_SHIFT;
                        break;
                case 1000:
                        if (!(community->features & PINCTRL_FEATURE_1K_PD)) {
                                ret = -EINVAL;
                                break;
                        }
                        value |= PADCFG1_TERM_1K << PADCFG1_TERM_SHIFT;
                        break;
                default:
                        ret = -EINVAL;
                }

                break;
        }

        if (!ret)
                writel(value, padcfg1);

        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return ret;
}

static int intel_config_set_debounce(struct intel_pinctrl *pctrl, unsigned pin,
                                     unsigned debounce)
{
        void __iomem *padcfg0, *padcfg2;
        unsigned long flags;
        u32 value0, value2;
        int ret = 0;

        padcfg2 = intel_get_padcfg(pctrl, pin, PADCFG2);
        if (!padcfg2)
                return -ENOTSUPP;

        padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        value0 = readl(padcfg0);
        value2 = readl(padcfg2);

        /* Disable glitch filter and debouncer */
        value0 &= ~PADCFG0_PREGFRXSEL;
        value2 &= ~(PADCFG2_DEBEN | PADCFG2_DEBOUNCE_MASK);

        if (debounce) {
                unsigned long v;

                v = order_base_2(debounce * 1000 / DEBOUNCE_PERIOD);
                if (v < 3 || v > 15) {
                        ret = -EINVAL;
                        goto exit_unlock;
                } else {
                        /* Enable glitch filter and debouncer */
                        value0 |= PADCFG0_PREGFRXSEL;
                        value2 |= v << PADCFG2_DEBOUNCE_SHIFT;
                        value2 |= PADCFG2_DEBEN;
                }
        }

        writel(value0, padcfg0);
        writel(value2, padcfg2);

exit_unlock:
        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return ret;
}

static int intel_config_set(struct pinctrl_dev *pctldev, unsigned pin,
                          unsigned long *configs, unsigned nconfigs)
{
        struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
        int i, ret;

        if (!intel_pad_usable(pctrl, pin))
                return -ENOTSUPP;

        for (i = 0; i < nconfigs; i++) {
                switch (pinconf_to_config_param(configs[i])) {
                case PIN_CONFIG_BIAS_DISABLE:
                case PIN_CONFIG_BIAS_PULL_UP:
                case PIN_CONFIG_BIAS_PULL_DOWN:
                        ret = intel_config_set_pull(pctrl, pin, configs[i]);
                        if (ret)
                                return ret;
                        break;

                case PIN_CONFIG_INPUT_DEBOUNCE:
                        ret = intel_config_set_debounce(pctrl, pin,
                                pinconf_to_config_argument(configs[i]));
                        if (ret)
                                return ret;
                        break;

                default:
                        return -ENOTSUPP;
                }
        }

        return 0;
}

static const struct pinconf_ops intel_pinconf_ops = {
        .is_generic = true,
        .pin_config_get = intel_config_get,
        .pin_config_set = intel_config_set,
};

static const struct pinctrl_desc intel_pinctrl_desc = {
        .pctlops = &intel_pinctrl_ops,
        .pmxops = &intel_pinmux_ops,
        .confops = &intel_pinconf_ops,
        .owner = THIS_MODULE,
};

static int intel_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct intel_pinctrl *pctrl = gpiochip_get_data(chip);
        void __iomem *reg;
        u32 padcfg0;

        reg = intel_get_padcfg(pctrl, offset, PADCFG0);
        if (!reg)
                return -EINVAL;

        padcfg0 = readl(reg);
        if (!(padcfg0 & PADCFG0_GPIOTXDIS))
                return !!(padcfg0 & PADCFG0_GPIOTXSTATE);

        return !!(padcfg0 & PADCFG0_GPIORXSTATE);
}

static void intel_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
        struct intel_pinctrl *pctrl = gpiochip_get_data(chip);
        unsigned long flags;
        void __iomem *reg;
        u32 padcfg0;

        reg = intel_get_padcfg(pctrl, offset, PADCFG0);
        if (!reg)
                return;

        raw_spin_lock_irqsave(&pctrl->lock, flags);
        padcfg0 = readl(reg);
        if (value)
                padcfg0 |= PADCFG0_GPIOTXSTATE;
        else
                padcfg0 &= ~PADCFG0_GPIOTXSTATE;
        writel(padcfg0, reg);
        raw_spin_unlock_irqrestore(&pctrl->lock, flags);
}

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

static int intel_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
                                       int value)
{
        intel_gpio_set(chip, offset, value);
        return pinctrl_gpio_direction_output(chip->base + offset);
}

static const struct gpio_chip intel_gpio_chip = {
        .owner = THIS_MODULE,
        .request = gpiochip_generic_request,
        .free = gpiochip_generic_free,
        .direction_input = intel_gpio_direction_input,
        .direction_output = intel_gpio_direction_output,
        .get = intel_gpio_get,
        .set = intel_gpio_set,
        .set_config = gpiochip_generic_config,
};

static void intel_gpio_irq_ack(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
        const struct intel_community *community;
        unsigned pin = irqd_to_hwirq(d);

        community = intel_get_community(pctrl, pin);
        if (community) {
                const struct intel_padgroup *padgrp;
                unsigned gpp, gpp_offset;

                padgrp = intel_community_get_padgroup(community, pin);
                if (!padgrp)
                        return;

                gpp = padgrp->reg_num;
                gpp_offset = padgroup_offset(padgrp, pin);

                raw_spin_lock(&pctrl->lock);
                writel(BIT(gpp_offset), community->regs + GPI_IS + gpp * 4);
                raw_spin_unlock(&pctrl->lock);
        }
}

static void intel_gpio_irq_enable(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
        const struct intel_community *community;
        unsigned pin = irqd_to_hwirq(d);

        community = intel_get_community(pctrl, pin);
        if (community) {
                const struct intel_padgroup *padgrp;
                unsigned gpp, gpp_offset;
                unsigned long flags;
                u32 value;

                padgrp = intel_community_get_padgroup(community, pin);
                if (!padgrp)
                        return;

                gpp = padgrp->reg_num;
                gpp_offset = padgroup_offset(padgrp, pin);

                raw_spin_lock_irqsave(&pctrl->lock, flags);
                /* Clear interrupt status first to avoid unexpected interrupt */
                writel(BIT(gpp_offset), community->regs + GPI_IS + gpp * 4);

                value = readl(community->regs + community->ie_offset + gpp * 4);
                value |= BIT(gpp_offset);
                writel(value, community->regs + community->ie_offset + gpp * 4);
                raw_spin_unlock_irqrestore(&pctrl->lock, flags);
        }
}

static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
        const struct intel_community *community;
        unsigned pin = irqd_to_hwirq(d);

        community = intel_get_community(pctrl, pin);
        if (community) {
                const struct intel_padgroup *padgrp;
                unsigned gpp, gpp_offset;
                unsigned long flags;
                void __iomem *reg;
                u32 value;

                padgrp = intel_community_get_padgroup(community, pin);
                if (!padgrp)
                        return;

                gpp = padgrp->reg_num;
                gpp_offset = padgroup_offset(padgrp, pin);

                reg = community->regs + community->ie_offset + gpp * 4;

                raw_spin_lock_irqsave(&pctrl->lock, flags);
                value = readl(reg);
                if (mask)
                        value &= ~BIT(gpp_offset);
                else
                        value |= BIT(gpp_offset);
                writel(value, reg);
                raw_spin_unlock_irqrestore(&pctrl->lock, flags);
        }
}

static void intel_gpio_irq_mask(struct irq_data *d)
{
        intel_gpio_irq_mask_unmask(d, true);
}

static void intel_gpio_irq_unmask(struct irq_data *d)
{
        intel_gpio_irq_mask_unmask(d, false);
}

static int intel_gpio_irq_type(struct irq_data *d, unsigned type)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
        unsigned pin = irqd_to_hwirq(d);
        unsigned long flags;
        void __iomem *reg;
        u32 value;

        reg = intel_get_padcfg(pctrl, pin, PADCFG0);
        if (!reg)
                return -EINVAL;

        /*
         * If the pin is in ACPI mode it is still usable as a GPIO but it
         * cannot be used as IRQ because GPI_IS status bit will not be
         * updated by the host controller hardware.
         */
        if (intel_pad_acpi_mode(pctrl, pin)) {
                dev_warn(pctrl->dev, "pin %u cannot be used as IRQ\n", pin);
                return -EPERM;
        }

        raw_spin_lock_irqsave(&pctrl->lock, flags);

        value = readl(reg);

        value &= ~(PADCFG0_RXEVCFG_MASK | PADCFG0_RXINV);

        if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
                value |= PADCFG0_RXEVCFG_EDGE_BOTH << PADCFG0_RXEVCFG_SHIFT;
        } else if (type & IRQ_TYPE_EDGE_FALLING) {
                value |= PADCFG0_RXEVCFG_EDGE << PADCFG0_RXEVCFG_SHIFT;
                value |= PADCFG0_RXINV;
        } else if (type & IRQ_TYPE_EDGE_RISING) {
                value |= PADCFG0_RXEVCFG_EDGE << PADCFG0_RXEVCFG_SHIFT;
        } else if (type & IRQ_TYPE_LEVEL_MASK) {
                if (type & IRQ_TYPE_LEVEL_LOW)
                        value |= PADCFG0_RXINV;
        } else {
                value |= PADCFG0_RXEVCFG_DISABLED << PADCFG0_RXEVCFG_SHIFT;
        }

        writel(value, reg);

        if (type & IRQ_TYPE_EDGE_BOTH)
                irq_set_handler_locked(d, handle_edge_irq);
        else if (type & IRQ_TYPE_LEVEL_MASK)
                irq_set_handler_locked(d, handle_level_irq);

        raw_spin_unlock_irqrestore(&pctrl->lock, flags);

        return 0;
}

static int intel_gpio_irq_wake(struct irq_data *d, unsigned int on)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
        unsigned pin = irqd_to_hwirq(d);

        if (on)
                enable_irq_wake(pctrl->irq);
        else
                disable_irq_wake(pctrl->irq);

        dev_dbg(pctrl->dev, "%sable wake for pin %u\n", on ? "en" : "dis", pin);
        return 0;
}

static irqreturn_t intel_gpio_community_irq_handler(struct intel_pinctrl *pctrl,
        const struct intel_community *community)
{
        struct gpio_chip *gc = &pctrl->chip;
        irqreturn_t ret = IRQ_NONE;
        int gpp;

        for (gpp = 0; gpp < community->ngpps; gpp++) {
                const struct intel_padgroup *padgrp = &community->gpps[gpp];
                unsigned long pending, enabled, gpp_offset;

                pending = readl(community->regs + GPI_IS + padgrp->reg_num * 4);
                enabled = readl(community->regs + community->ie_offset +
                                padgrp->reg_num * 4);

                /* Only interrupts that are enabled */
                pending &= enabled;

                for_each_set_bit(gpp_offset, &pending, padgrp->size) {
                        unsigned padno, irq;

                        padno = padgrp->base - community->pin_base + gpp_offset;
                        if (padno >= community->npins)
                                break;

                        irq = irq_find_mapping(gc->irqdomain,
                                               community->pin_base + padno);
                        generic_handle_irq(irq);

                        ret |= IRQ_HANDLED;
                }
        }

        return ret;
}

static irqreturn_t intel_gpio_irq(int irq, void *data)
{
        const struct intel_community *community;
        struct intel_pinctrl *pctrl = data;
        irqreturn_t ret = IRQ_NONE;
        int i;

        /* Need to check all communities for pending interrupts */
        for (i = 0; i < pctrl->ncommunities; i++) {
                community = &pctrl->communities[i];
                ret |= intel_gpio_community_irq_handler(pctrl, community);
        }

        return ret;
}

static struct irq_chip intel_gpio_irqchip = {
        .name = "intel-gpio",
        .irq_enable = intel_gpio_irq_enable,
        .irq_ack = intel_gpio_irq_ack,
        .irq_mask = intel_gpio_irq_mask,
        .irq_unmask = intel_gpio_irq_unmask,
        .irq_set_type = intel_gpio_irq_type,
        .irq_set_wake = intel_gpio_irq_wake,
        .flags = IRQCHIP_MASK_ON_SUSPEND,
};

static int intel_gpio_probe(struct intel_pinctrl *pctrl, int irq)
{
        int ret;

        pctrl->chip = intel_gpio_chip;

        pctrl->chip.ngpio = pctrl->soc->npins;
        pctrl->chip.label = dev_name(pctrl->dev);
        pctrl->chip.parent = pctrl->dev;
        pctrl->chip.base = -1;
        pctrl->irq = irq;

        ret = devm_gpiochip_add_data(pctrl->dev, &pctrl->chip, pctrl);
        if (ret) {
                dev_err(pctrl->dev, "failed to register gpiochip\n");
                return ret;
        }

        ret = gpiochip_add_pin_range(&pctrl->chip, dev_name(pctrl->dev),
                                     0, 0, pctrl->soc->npins);
        if (ret) {
                dev_err(pctrl->dev, "failed to add GPIO pin range\n");
                return ret;
        }

        /*
         * We need to request the interrupt here (instead of providing chip
         * to the irq directly) because on some platforms several GPIO
         * controllers share the same interrupt line.
         */
        ret = devm_request_irq(pctrl->dev, irq, intel_gpio_irq,
                               IRQF_SHARED | IRQF_NO_THREAD,
                               dev_name(pctrl->dev), pctrl);
        if (ret) {
                dev_err(pctrl->dev, "failed to request interrupt\n");
                return ret;
        }

        ret = gpiochip_irqchip_add(&pctrl->chip, &intel_gpio_irqchip, 0,
                                   handle_bad_irq, IRQ_TYPE_NONE);
        if (ret) {
                dev_err(pctrl->dev, "failed to add irqchip\n");
                return ret;
        }

        gpiochip_set_chained_irqchip(&pctrl->chip, &intel_gpio_irqchip, irq,
                                     NULL);
        return 0;
}

static int intel_pinctrl_add_padgroups(struct intel_pinctrl *pctrl,
                                       struct intel_community *community)
{
        struct intel_padgroup *gpps;
        unsigned npins = community->npins;
        unsigned padown_num = 0;
        size_t ngpps, i;

        if (community->gpps)
                ngpps = community->ngpps;
        else
                ngpps = DIV_ROUND_UP(community->npins, community->gpp_size);

        gpps = devm_kcalloc(pctrl->dev, ngpps, sizeof(*gpps), GFP_KERNEL);
        if (!gpps)
                return -ENOMEM;

        for (i = 0; i < ngpps; i++) {
                if (community->gpps) {
                        gpps[i] = community->gpps[i];
                } else {
                        unsigned gpp_size = community->gpp_size;

                        gpps[i].reg_num = i;
                        gpps[i].base = community->pin_base + i * gpp_size;
                        gpps[i].size = min(gpp_size, npins);
                        npins -= gpps[i].size;
                }

                if (gpps[i].size > 32)
                        return -EINVAL;

                gpps[i].padown_num = padown_num;

                /*
                 * In older hardware the number of padown registers per
                 * group is fixed regardless of the group size.
                 */
                if (community->gpp_num_padown_regs)
                        padown_num += community->gpp_num_padown_regs;
                else
                        padown_num += DIV_ROUND_UP(gpps[i].size * 4, 32);
        }

        community->ngpps = ngpps;
        community->gpps = gpps;

        return 0;
}

static int intel_pinctrl_pm_init(struct intel_pinctrl *pctrl)
{
#ifdef CONFIG_PM_SLEEP
        const struct intel_pinctrl_soc_data *soc = pctrl->soc;
        struct intel_community_context *communities;
        struct intel_pad_context *pads;
        int i;

        pads = devm_kcalloc(pctrl->dev, soc->npins, sizeof(*pads), GFP_KERNEL);
        if (!pads)
                return -ENOMEM;

        communities = devm_kcalloc(pctrl->dev, pctrl->ncommunities,
                                   sizeof(*communities), GFP_KERNEL);
        if (!communities)
                return -ENOMEM;


        for (i = 0; i < pctrl->ncommunities; i++) {
                struct intel_community *community = &pctrl->communities[i];
                u32 *intmask;

                intmask = devm_kcalloc(pctrl->dev, community->ngpps,
                                       sizeof(*intmask), GFP_KERNEL);
                if (!intmask)
                        return -ENOMEM;

                communities[i].intmask = intmask;
        }

        pctrl->context.pads = pads;
        pctrl->context.communities = communities;
#endif

        return 0;
}

int intel_pinctrl_probe(struct platform_device *pdev,
                        const struct intel_pinctrl_soc_data *soc_data)
{
        struct intel_pinctrl *pctrl;
        int i, ret, irq;

        if (!soc_data)
                return -EINVAL;

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

        pctrl->dev = &pdev->dev;
        pctrl->soc = soc_data;
        raw_spin_lock_init(&pctrl->lock);

        /*
         * Make a copy of the communities which we can use to hold pointers
         * to the registers.
         */
        pctrl->ncommunities = pctrl->soc->ncommunities;
        pctrl->communities = devm_kcalloc(&pdev->dev, pctrl->ncommunities,
                                  sizeof(*pctrl->communities), GFP_KERNEL);
        if (!pctrl->communities)
                return -ENOMEM;

        for (i = 0; i < pctrl->ncommunities; i++) {
                struct intel_community *community = &pctrl->communities[i];
                struct resource *res;
                void __iomem *regs;
                u32 padbar;

                *community = pctrl->soc->communities[i];

                res = platform_get_resource(pdev, IORESOURCE_MEM,
                                            community->barno);
                regs = devm_ioremap_resource(&pdev->dev, res);
                if (IS_ERR(regs))
                        return PTR_ERR(regs);

                /*
                 * Determine community features based on the revision if
                 * not specified already.
                 */
                if (!community->features) {
                        u32 rev;

                        rev = (readl(regs + REVID) & REVID_MASK) >> REVID_SHIFT;
                        if (rev >= 0x94) {
                                community->features |= PINCTRL_FEATURE_DEBOUNCE;
                                community->features |= PINCTRL_FEATURE_1K_PD;
                        }
                }

                /* Read offset of the pad configuration registers */
                padbar = readl(regs + PADBAR);

                community->regs = regs;
                community->pad_regs = regs + padbar;

                ret = intel_pinctrl_add_padgroups(pctrl, community);
                if (ret)
                        return ret;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_err(&pdev->dev, "failed to get interrupt number\n");
                return irq;
        }

        ret = intel_pinctrl_pm_init(pctrl);
        if (ret)
                return ret;

        pctrl->pctldesc = intel_pinctrl_desc;
        pctrl->pctldesc.name = dev_name(&pdev->dev);
        pctrl->pctldesc.pins = pctrl->soc->pins;
        pctrl->pctldesc.npins = pctrl->soc->npins;

        pctrl->pctldev = devm_pinctrl_register(&pdev->dev, &pctrl->pctldesc,
                                               pctrl);
        if (IS_ERR(pctrl->pctldev)) {
                dev_err(&pdev->dev, "failed to register pinctrl driver\n");
                return PTR_ERR(pctrl->pctldev);
        }

        ret = intel_gpio_probe(pctrl, irq);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, pctrl);

        return 0;
}
EXPORT_SYMBOL_GPL(intel_pinctrl_probe);

#ifdef CONFIG_PM_SLEEP
static bool intel_pinctrl_should_save(struct intel_pinctrl *pctrl, unsigned pin)
{
        const struct pin_desc *pd = pin_desc_get(pctrl->pctldev, pin);

        if (!pd || !intel_pad_usable(pctrl, pin))
                return false;

        /*
         * Only restore the pin if it is actually in use by the kernel (or
         * by userspace). It is possible that some pins are used by the
         * BIOS during resume and those are not always locked down so leave
         * them alone.
         */
        if (pd->mux_owner || pd->gpio_owner ||
            gpiochip_line_is_irq(&pctrl->chip, pin))
                return true;

        return false;
}

int intel_pinctrl_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct intel_pinctrl *pctrl = platform_get_drvdata(pdev);
        struct intel_community_context *communities;
        struct intel_pad_context *pads;
        int i;

        pads = pctrl->context.pads;
        for (i = 0; i < pctrl->soc->npins; i++) {
                const struct pinctrl_pin_desc *desc = &pctrl->soc->pins[i];
                void __iomem *padcfg;
                u32 val;

                if (!intel_pinctrl_should_save(pctrl, desc->number))
                        continue;

                val = readl(intel_get_padcfg(pctrl, desc->number, PADCFG0));
                pads[i].padcfg0 = val & ~PADCFG0_GPIORXSTATE;
                val = readl(intel_get_padcfg(pctrl, desc->number, PADCFG1));
                pads[i].padcfg1 = val;

                padcfg = intel_get_padcfg(pctrl, desc->number, PADCFG2);
                if (padcfg)
                        pads[i].padcfg2 = readl(padcfg);
        }

        communities = pctrl->context.communities;
        for (i = 0; i < pctrl->ncommunities; i++) {
                struct intel_community *community = &pctrl->communities[i];
                void __iomem *base;
                unsigned gpp;

                base = community->regs + community->ie_offset;
                for (gpp = 0; gpp < community->ngpps; gpp++)
                        communities[i].intmask[gpp] = readl(base + gpp * 4);
        }

        return 0;
}
EXPORT_SYMBOL_GPL(intel_pinctrl_suspend);

static void intel_gpio_irq_init(struct intel_pinctrl *pctrl)
{
        size_t i;

        for (i = 0; i < pctrl->ncommunities; i++) {
                const struct intel_community *community;
                void __iomem *base;
                unsigned gpp;

                community = &pctrl->communities[i];
                base = community->regs;

                for (gpp = 0; gpp < community->ngpps; gpp++) {
                        /* Mask and clear all interrupts */
                        writel(0, base + community->ie_offset + gpp * 4);
                        writel(0xffff, base + GPI_IS + gpp * 4);
                }
        }
}

int intel_pinctrl_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct intel_pinctrl *pctrl = platform_get_drvdata(pdev);
        const struct intel_community_context *communities;
        const struct intel_pad_context *pads;
        int i;

        /* Mask all interrupts */
        intel_gpio_irq_init(pctrl);

        pads = pctrl->context.pads;
        for (i = 0; i < pctrl->soc->npins; i++) {
                const struct pinctrl_pin_desc *desc = &pctrl->soc->pins[i];
                void __iomem *padcfg;
                u32 val;

                if (!intel_pinctrl_should_save(pctrl, desc->number))
                        continue;

                padcfg = intel_get_padcfg(pctrl, desc->number, PADCFG0);
                val = readl(padcfg) & ~PADCFG0_GPIORXSTATE;
                if (val != pads[i].padcfg0) {
                        writel(pads[i].padcfg0, padcfg);
                        dev_dbg(dev, "restored pin %u padcfg0 %#08x\n",
                                desc->number, readl(padcfg));
                }

                padcfg = intel_get_padcfg(pctrl, desc->number, PADCFG1);
                val = readl(padcfg);
                if (val != pads[i].padcfg1) {
                        writel(pads[i].padcfg1, padcfg);
                        dev_dbg(dev, "restored pin %u padcfg1 %#08x\n",
                                desc->number, readl(padcfg));
                }

                padcfg = intel_get_padcfg(pctrl, desc->number, PADCFG2);
                if (padcfg) {
                        val = readl(padcfg);
                        if (val != pads[i].padcfg2) {
                                writel(pads[i].padcfg2, padcfg);
                                dev_dbg(dev, "restored pin %u padcfg2 %#08x\n",
                                        desc->number, readl(padcfg));
                        }
                }
        }

        communities = pctrl->context.communities;
        for (i = 0; i < pctrl->ncommunities; i++) {
                struct intel_community *community = &pctrl->communities[i];
                void __iomem *base;
                unsigned gpp;

                base = community->regs + community->ie_offset;
                for (gpp = 0; gpp < community->ngpps; gpp++) {
                        writel(communities[i].intmask[gpp], base + gpp * 4);
                        dev_dbg(dev, "restored mask %d/%u %#08x\n", i, gpp,
                                readl(base + gpp * 4));
                }
        }

        return 0;
}
EXPORT_SYMBOL_GPL(intel_pinctrl_resume);
#endif

MODULE_AUTHOR("Mathias Nyman <mathias.nyman@linux.intel.com>");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_DESCRIPTION("Intel pinctrl/GPIO core driver");
MODULE_LICENSE("GPL v2");