/*
 * at91 pinctrl driver based on at91 pinmux core
 *
 * Copyright (C) 2011-2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
 *
 * Under GPLv2 only
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
/* Since we request GPIOs from ourself */
#include <linux/pinctrl/consumer.h>

#include "pinctrl-at91.h"
#include "core.h"

#define MAX_GPIO_BANKS          5
#define MAX_NB_GPIO_PER_BANK    32

struct at91_pinctrl_mux_ops;

struct at91_gpio_chip {
        struct gpio_chip        chip;
        struct pinctrl_gpio_range range;
        struct at91_gpio_chip   *next;          /* Bank sharing same clock */
        int                     pioc_hwirq;     /* PIO bank interrupt identifier on AIC */
        int                     pioc_virq;      /* PIO bank Linux virtual interrupt */
        int                     pioc_idx;       /* PIO bank index */
        void __iomem            *regbase;       /* PIO bank virtual address */
        struct clk              *clock;         /* associated clock */
        struct at91_pinctrl_mux_ops *ops;       /* ops */
};

static struct at91_gpio_chip *gpio_chips[MAX_GPIO_BANKS];

static int gpio_banks;

#define PULL_UP         (1 << 0)
#define MULTI_DRIVE     (1 << 1)
#define DEGLITCH        (1 << 2)
#define PULL_DOWN       (1 << 3)
#define DIS_SCHMIT      (1 << 4)
#define DRIVE_STRENGTH_SHIFT    5
#define DRIVE_STRENGTH_MASK             0x3
#define DRIVE_STRENGTH   (DRIVE_STRENGTH_MASK << DRIVE_STRENGTH_SHIFT)
#define OUTPUT          (1 << 7)
#define OUTPUT_VAL_SHIFT        8
#define OUTPUT_VAL      (0x1 << OUTPUT_VAL_SHIFT)
#define DEBOUNCE        (1 << 16)
#define DEBOUNCE_VAL_SHIFT      17
#define DEBOUNCE_VAL    (0x3fff << DEBOUNCE_VAL_SHIFT)

/**
 * These defines will translated the dt binding settings to our internal
 * settings. They are not necessarily the same value as the register setting.
 * The actual drive strength current of low, medium and high must be looked up
 * from the corresponding device datasheet. This value is different for pins
 * that are even in the same banks. It is also dependent on VCC.
 * DRIVE_STRENGTH_DEFAULT is just a placeholder to avoid changing the drive
 * strength when there is no dt config for it.
 */
#define DRIVE_STRENGTH_DEFAULT          (0 << DRIVE_STRENGTH_SHIFT)
#define DRIVE_STRENGTH_LOW          (1 << DRIVE_STRENGTH_SHIFT)
#define DRIVE_STRENGTH_MED          (2 << DRIVE_STRENGTH_SHIFT)
#define DRIVE_STRENGTH_HI           (3 << DRIVE_STRENGTH_SHIFT)

/**
 * struct at91_pmx_func - describes AT91 pinmux functions
 * @name: the name of this specific function
 * @groups: corresponding pin groups
 * @ngroups: the number of groups
 */
struct at91_pmx_func {
        const char      *name;
        const char      **groups;
        unsigned        ngroups;
};

enum at91_mux {
        AT91_MUX_GPIO = 0,
        AT91_MUX_PERIPH_A = 1,
        AT91_MUX_PERIPH_B = 2,
        AT91_MUX_PERIPH_C = 3,
        AT91_MUX_PERIPH_D = 4,
};

/**
 * struct at91_pmx_pin - describes an At91 pin mux
 * @bank: the bank of the pin
 * @pin: the pin number in the @bank
 * @mux: the mux mode : gpio or periph_x of the pin i.e. alternate function.
 * @conf: the configuration of the pin: PULL_UP, MULTIDRIVE etc...
 */
struct at91_pmx_pin {
        uint32_t        bank;
        uint32_t        pin;
        enum at91_mux   mux;
        unsigned long   conf;
};

/**
 * struct at91_pin_group - describes an At91 pin group
 * @name: the name of this specific pin group
 * @pins_conf: the mux mode for each pin in this group. The size of this
 *      array is the same as pins.
 * @pins: an array of discrete physical pins used in this group, taken
 *      from the driver-local pin enumeration space
 * @npins: the number of pins in this group array, i.e. the number of
 *      elements in .pins so we can iterate over that array
 */
struct at91_pin_group {
        const char              *name;
        struct at91_pmx_pin     *pins_conf;
        unsigned int            *pins;
        unsigned                npins;
};

/**
 * struct at91_pinctrl_mux_ops - describes an AT91 mux ops group
 * on new IP with support for periph C and D the way to mux in
 * periph A and B has changed
 * So provide the right call back
 * if not present means the IP does not support it
 * @get_periph: return the periph mode configured
 * @mux_A_periph: mux as periph A
 * @mux_B_periph: mux as periph B
 * @mux_C_periph: mux as periph C
 * @mux_D_periph: mux as periph D
 * @get_deglitch: get deglitch status
 * @set_deglitch: enable/disable deglitch
 * @get_debounce: get debounce status
 * @set_debounce: enable/disable debounce
 * @get_pulldown: get pulldown status
 * @set_pulldown: enable/disable pulldown
 * @get_schmitt_trig: get schmitt trigger status
 * @disable_schmitt_trig: disable schmitt trigger
 * @irq_type: return irq type
 */
struct at91_pinctrl_mux_ops {
        enum at91_mux (*get_periph)(void __iomem *pio, unsigned mask);
        void (*mux_A_periph)(void __iomem *pio, unsigned mask);
        void (*mux_B_periph)(void __iomem *pio, unsigned mask);
        void (*mux_C_periph)(void __iomem *pio, unsigned mask);
        void (*mux_D_periph)(void __iomem *pio, unsigned mask);
        bool (*get_deglitch)(void __iomem *pio, unsigned pin);
        void (*set_deglitch)(void __iomem *pio, unsigned mask, bool is_on);
        bool (*get_debounce)(void __iomem *pio, unsigned pin, u32 *div);
        void (*set_debounce)(void __iomem *pio, unsigned mask, bool is_on, u32 div);
        bool (*get_pulldown)(void __iomem *pio, unsigned pin);
        void (*set_pulldown)(void __iomem *pio, unsigned mask, bool is_on);
        bool (*get_schmitt_trig)(void __iomem *pio, unsigned pin);
        void (*disable_schmitt_trig)(void __iomem *pio, unsigned mask);
        unsigned (*get_drivestrength)(void __iomem *pio, unsigned pin);
        void (*set_drivestrength)(void __iomem *pio, unsigned pin,
                                        u32 strength);
        /* irq */
        int (*irq_type)(struct irq_data *d, unsigned type);
};

static int gpio_irq_type(struct irq_data *d, unsigned type);
static int alt_gpio_irq_type(struct irq_data *d, unsigned type);

struct at91_pinctrl {
        struct device           *dev;
        struct pinctrl_dev      *pctl;

        int                     nactive_banks;

        uint32_t                *mux_mask;
        int                     nmux;

        struct at91_pmx_func    *functions;
        int                     nfunctions;

        struct at91_pin_group   *groups;
        int                     ngroups;

        struct at91_pinctrl_mux_ops *ops;
};

static inline const struct at91_pin_group *at91_pinctrl_find_group_by_name(
                                const struct at91_pinctrl *info,
                                const char *name)
{
        const struct at91_pin_group *grp = NULL;
        int i;

        for (i = 0; i < info->ngroups; i++) {
                if (strcmp(info->groups[i].name, name))
                        continue;

                grp = &info->groups[i];
                dev_dbg(info->dev, "%s: %d 0:%d\n", name, grp->npins, grp->pins[0]);
                break;
        }

        return grp;
}

static int at91_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->ngroups;
}

static const char *at91_get_group_name(struct pinctrl_dev *pctldev,
                                       unsigned selector)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

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

static int at91_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
                               const unsigned **pins,
                               unsigned *npins)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        if (selector >= info->ngroups)
                return -EINVAL;

        *pins = info->groups[selector].pins;
        *npins = info->groups[selector].npins;

        return 0;
}

static void at91_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
                   unsigned offset)
{
        seq_printf(s, "%s", dev_name(pctldev->dev));
}

static int at91_dt_node_to_map(struct pinctrl_dev *pctldev,
                        struct device_node *np,
                        struct pinctrl_map **map, unsigned *num_maps)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        const struct at91_pin_group *grp;
        struct pinctrl_map *new_map;
        struct device_node *parent;
        int map_num = 1;
        int i;

        /*
         * first find the group of this node and check if we need to create
         * config maps for pins
         */
        grp = at91_pinctrl_find_group_by_name(info, np->name);
        if (!grp) {
                dev_err(info->dev, "unable to find group for node %s\n",
                        np->name);
                return -EINVAL;
        }

        map_num += grp->npins;
        new_map = devm_kcalloc(pctldev->dev, map_num, sizeof(*new_map),
                               GFP_KERNEL);
        if (!new_map)
                return -ENOMEM;

        *map = new_map;
        *num_maps = map_num;

        /* create mux map */
        parent = of_get_parent(np);
        if (!parent) {
                devm_kfree(pctldev->dev, new_map);
                return -EINVAL;
        }
        new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
        new_map[0].data.mux.function = parent->name;
        new_map[0].data.mux.group = np->name;
        of_node_put(parent);

        /* create config map */
        new_map++;
        for (i = 0; i < grp->npins; i++) {
                new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;
                new_map[i].data.configs.group_or_pin =
                                pin_get_name(pctldev, grp->pins[i]);
                new_map[i].data.configs.configs = &grp->pins_conf[i].conf;
                new_map[i].data.configs.num_configs = 1;
        }

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

        return 0;
}

static void at91_dt_free_map(struct pinctrl_dev *pctldev,
                                struct pinctrl_map *map, unsigned num_maps)
{
}

static const struct pinctrl_ops at91_pctrl_ops = {
        .get_groups_count       = at91_get_groups_count,
        .get_group_name         = at91_get_group_name,
        .get_group_pins         = at91_get_group_pins,
        .pin_dbg_show           = at91_pin_dbg_show,
        .dt_node_to_map         = at91_dt_node_to_map,
        .dt_free_map            = at91_dt_free_map,
};

static void __iomem *pin_to_controller(struct at91_pinctrl *info,
                                 unsigned int bank)
{
        if (!gpio_chips[bank])
                return NULL;

        return gpio_chips[bank]->regbase;
}

static inline int pin_to_bank(unsigned pin)
{
        return pin /= MAX_NB_GPIO_PER_BANK;
}

static unsigned pin_to_mask(unsigned int pin)
{
        return 1 << pin;
}

static unsigned two_bit_pin_value_shift_amount(unsigned int pin)
{
        /* return the shift value for a pin for "two bit" per pin registers,
         * i.e. drive strength */
        return 2*((pin >= MAX_NB_GPIO_PER_BANK/2)
                        ? pin - MAX_NB_GPIO_PER_BANK/2 : pin);
}

static unsigned sama5d3_get_drive_register(unsigned int pin)
{
        /* drive strength is split between two registers
         * with two bits per pin */
        return (pin >= MAX_NB_GPIO_PER_BANK/2)
                        ? SAMA5D3_PIO_DRIVER2 : SAMA5D3_PIO_DRIVER1;
}

static unsigned at91sam9x5_get_drive_register(unsigned int pin)
{
        /* drive strength is split between two registers
         * with two bits per pin */
        return (pin >= MAX_NB_GPIO_PER_BANK/2)
                        ? AT91SAM9X5_PIO_DRIVER2 : AT91SAM9X5_PIO_DRIVER1;
}

static void at91_mux_disable_interrupt(void __iomem *pio, unsigned mask)
{
        writel_relaxed(mask, pio + PIO_IDR);
}

static unsigned at91_mux_get_pullup(void __iomem *pio, unsigned pin)
{
        return !((readl_relaxed(pio + PIO_PUSR) >> pin) & 0x1);
}

static void at91_mux_set_pullup(void __iomem *pio, unsigned mask, bool on)
{
        if (on)
                writel_relaxed(mask, pio + PIO_PPDDR);

        writel_relaxed(mask, pio + (on ? PIO_PUER : PIO_PUDR));
}

static bool at91_mux_get_output(void __iomem *pio, unsigned int pin, bool *val)
{
        *val = (readl_relaxed(pio + PIO_ODSR) >> pin) & 0x1;
        return (readl_relaxed(pio + PIO_OSR) >> pin) & 0x1;
}

static void at91_mux_set_output(void __iomem *pio, unsigned int mask,
                                bool is_on, bool val)
{
        writel_relaxed(mask, pio + (val ? PIO_SODR : PIO_CODR));
        writel_relaxed(mask, pio + (is_on ? PIO_OER : PIO_ODR));
}

static unsigned at91_mux_get_multidrive(void __iomem *pio, unsigned pin)
{
        return (readl_relaxed(pio + PIO_MDSR) >> pin) & 0x1;
}

static void at91_mux_set_multidrive(void __iomem *pio, unsigned mask, bool on)
{
        writel_relaxed(mask, pio + (on ? PIO_MDER : PIO_MDDR));
}

static void at91_mux_set_A_periph(void __iomem *pio, unsigned mask)
{
        writel_relaxed(mask, pio + PIO_ASR);
}

static void at91_mux_set_B_periph(void __iomem *pio, unsigned mask)
{
        writel_relaxed(mask, pio + PIO_BSR);
}

static void at91_mux_pio3_set_A_periph(void __iomem *pio, unsigned mask)
{

        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR1) & ~mask,
                                                pio + PIO_ABCDSR1);
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR2) & ~mask,
                                                pio + PIO_ABCDSR2);
}

static void at91_mux_pio3_set_B_periph(void __iomem *pio, unsigned mask)
{
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR1) | mask,
                                                pio + PIO_ABCDSR1);
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR2) & ~mask,
                                                pio + PIO_ABCDSR2);
}

static void at91_mux_pio3_set_C_periph(void __iomem *pio, unsigned mask)
{
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR1) & ~mask, pio + PIO_ABCDSR1);
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR2) | mask, pio + PIO_ABCDSR2);
}

static void at91_mux_pio3_set_D_periph(void __iomem *pio, unsigned mask)
{
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR1) | mask, pio + PIO_ABCDSR1);
        writel_relaxed(readl_relaxed(pio + PIO_ABCDSR2) | mask, pio + PIO_ABCDSR2);
}

static enum at91_mux at91_mux_pio3_get_periph(void __iomem *pio, unsigned mask)
{
        unsigned select;

        if (readl_relaxed(pio + PIO_PSR) & mask)
                return AT91_MUX_GPIO;

        select = !!(readl_relaxed(pio + PIO_ABCDSR1) & mask);
        select |= (!!(readl_relaxed(pio + PIO_ABCDSR2) & mask) << 1);

        return select + 1;
}

static enum at91_mux at91_mux_get_periph(void __iomem *pio, unsigned mask)
{
        unsigned select;

        if (readl_relaxed(pio + PIO_PSR) & mask)
                return AT91_MUX_GPIO;

        select = readl_relaxed(pio + PIO_ABSR) & mask;

        return select + 1;
}

static bool at91_mux_get_deglitch(void __iomem *pio, unsigned pin)
{
        return (readl_relaxed(pio + PIO_IFSR) >> pin) & 0x1;
}

static void at91_mux_set_deglitch(void __iomem *pio, unsigned mask, bool is_on)
{
        writel_relaxed(mask, pio + (is_on ? PIO_IFER : PIO_IFDR));
}

static bool at91_mux_pio3_get_deglitch(void __iomem *pio, unsigned pin)
{
        if ((readl_relaxed(pio + PIO_IFSR) >> pin) & 0x1)
                return !((readl_relaxed(pio + PIO_IFSCSR) >> pin) & 0x1);

        return false;
}

static void at91_mux_pio3_set_deglitch(void __iomem *pio, unsigned mask, bool is_on)
{
        if (is_on)
                writel_relaxed(mask, pio + PIO_IFSCDR);
        at91_mux_set_deglitch(pio, mask, is_on);
}

static bool at91_mux_pio3_get_debounce(void __iomem *pio, unsigned pin, u32 *div)
{
        *div = readl_relaxed(pio + PIO_SCDR);

        return ((readl_relaxed(pio + PIO_IFSR) >> pin) & 0x1) &&
               ((readl_relaxed(pio + PIO_IFSCSR) >> pin) & 0x1);
}

static void at91_mux_pio3_set_debounce(void __iomem *pio, unsigned mask,
                                bool is_on, u32 div)
{
        if (is_on) {
                writel_relaxed(mask, pio + PIO_IFSCER);
                writel_relaxed(div & PIO_SCDR_DIV, pio + PIO_SCDR);
                writel_relaxed(mask, pio + PIO_IFER);
        } else
                writel_relaxed(mask, pio + PIO_IFSCDR);
}

static bool at91_mux_pio3_get_pulldown(void __iomem *pio, unsigned pin)
{
        return !((readl_relaxed(pio + PIO_PPDSR) >> pin) & 0x1);
}

static void at91_mux_pio3_set_pulldown(void __iomem *pio, unsigned mask, bool is_on)
{
        if (is_on)
                writel_relaxed(mask, pio + PIO_PUDR);

        writel_relaxed(mask, pio + (is_on ? PIO_PPDER : PIO_PPDDR));
}

static void at91_mux_pio3_disable_schmitt_trig(void __iomem *pio, unsigned mask)
{
        writel_relaxed(readl_relaxed(pio + PIO_SCHMITT) | mask, pio + PIO_SCHMITT);
}

static bool at91_mux_pio3_get_schmitt_trig(void __iomem *pio, unsigned pin)
{
        return (readl_relaxed(pio + PIO_SCHMITT) >> pin) & 0x1;
}

static inline u32 read_drive_strength(void __iomem *reg, unsigned pin)
{
        unsigned tmp = readl_relaxed(reg);

        tmp = tmp >> two_bit_pin_value_shift_amount(pin);

        return tmp & DRIVE_STRENGTH_MASK;
}

static unsigned at91_mux_sama5d3_get_drivestrength(void __iomem *pio,
                                                        unsigned pin)
{
        unsigned tmp = read_drive_strength(pio +
                                        sama5d3_get_drive_register(pin), pin);

        /* SAMA5 strength is 1:1 with our defines,
         * except 0 is equivalent to low per datasheet */
        if (!tmp)
                tmp = DRIVE_STRENGTH_LOW;

        return tmp;
}

static unsigned at91_mux_sam9x5_get_drivestrength(void __iomem *pio,
                                                        unsigned pin)
{
        unsigned tmp = read_drive_strength(pio +
                                at91sam9x5_get_drive_register(pin), pin);

        /* strength is inverse in SAM9x5s hardware with the pinctrl defines
         * hardware: 0 = hi, 1 = med, 2 = low, 3 = rsvd */
        tmp = DRIVE_STRENGTH_HI - tmp;

        return tmp;
}

static void set_drive_strength(void __iomem *reg, unsigned pin, u32 strength)
{
        unsigned tmp = readl_relaxed(reg);
        unsigned shift = two_bit_pin_value_shift_amount(pin);

        tmp &= ~(DRIVE_STRENGTH_MASK  <<  shift);
        tmp |= strength << shift;

        writel_relaxed(tmp, reg);
}

static void at91_mux_sama5d3_set_drivestrength(void __iomem *pio, unsigned pin,
                                                u32 setting)
{
        /* do nothing if setting is zero */
        if (!setting)
                return;

        /* strength is 1 to 1 with setting for SAMA5 */
        set_drive_strength(pio + sama5d3_get_drive_register(pin), pin, setting);
}

static void at91_mux_sam9x5_set_drivestrength(void __iomem *pio, unsigned pin,
                                                u32 setting)
{
        /* do nothing if setting is zero */
        if (!setting)
                return;

        /* strength is inverse on SAM9x5s with our defines
         * 0 = hi, 1 = med, 2 = low, 3 = rsvd */
        setting = DRIVE_STRENGTH_HI - setting;

        set_drive_strength(pio + at91sam9x5_get_drive_register(pin), pin,
                                setting);
}

static struct at91_pinctrl_mux_ops at91rm9200_ops = {
        .get_periph     = at91_mux_get_periph,
        .mux_A_periph   = at91_mux_set_A_periph,
        .mux_B_periph   = at91_mux_set_B_periph,
        .get_deglitch   = at91_mux_get_deglitch,
        .set_deglitch   = at91_mux_set_deglitch,
        .irq_type       = gpio_irq_type,
};

static struct at91_pinctrl_mux_ops at91sam9x5_ops = {
        .get_periph     = at91_mux_pio3_get_periph,
        .mux_A_periph   = at91_mux_pio3_set_A_periph,
        .mux_B_periph   = at91_mux_pio3_set_B_periph,
        .mux_C_periph   = at91_mux_pio3_set_C_periph,
        .mux_D_periph   = at91_mux_pio3_set_D_periph,
        .get_deglitch   = at91_mux_pio3_get_deglitch,
        .set_deglitch   = at91_mux_pio3_set_deglitch,
        .get_debounce   = at91_mux_pio3_get_debounce,
        .set_debounce   = at91_mux_pio3_set_debounce,
        .get_pulldown   = at91_mux_pio3_get_pulldown,
        .set_pulldown   = at91_mux_pio3_set_pulldown,
        .get_schmitt_trig = at91_mux_pio3_get_schmitt_trig,
        .disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
        .get_drivestrength = at91_mux_sam9x5_get_drivestrength,
        .set_drivestrength = at91_mux_sam9x5_set_drivestrength,
        .irq_type       = alt_gpio_irq_type,
};

static struct at91_pinctrl_mux_ops sama5d3_ops = {
        .get_periph     = at91_mux_pio3_get_periph,
        .mux_A_periph   = at91_mux_pio3_set_A_periph,
        .mux_B_periph   = at91_mux_pio3_set_B_periph,
        .mux_C_periph   = at91_mux_pio3_set_C_periph,
        .mux_D_periph   = at91_mux_pio3_set_D_periph,
        .get_deglitch   = at91_mux_pio3_get_deglitch,
        .set_deglitch   = at91_mux_pio3_set_deglitch,
        .get_debounce   = at91_mux_pio3_get_debounce,
        .set_debounce   = at91_mux_pio3_set_debounce,
        .get_pulldown   = at91_mux_pio3_get_pulldown,
        .set_pulldown   = at91_mux_pio3_set_pulldown,
        .get_schmitt_trig = at91_mux_pio3_get_schmitt_trig,
        .disable_schmitt_trig = at91_mux_pio3_disable_schmitt_trig,
        .get_drivestrength = at91_mux_sama5d3_get_drivestrength,
        .set_drivestrength = at91_mux_sama5d3_set_drivestrength,
        .irq_type       = alt_gpio_irq_type,
};

static void at91_pin_dbg(const struct device *dev, const struct at91_pmx_pin *pin)
{
        if (pin->mux) {
                dev_dbg(dev, "pio%c%d configured as periph%c with conf = 0x%lx\n",
                        pin->bank + 'A', pin->pin, pin->mux - 1 + 'A', pin->conf);
        } else {
                dev_dbg(dev, "pio%c%d configured as gpio with conf = 0x%lx\n",
                        pin->bank + 'A', pin->pin, pin->conf);
        }
}

static int pin_check_config(struct at91_pinctrl *info, const char *name,
                            int index, const struct at91_pmx_pin *pin)
{
        int mux;

        /* check if it's a valid config */
        if (pin->bank >= gpio_banks) {
                dev_err(info->dev, "%s: pin conf %d bank_id %d >= nbanks %d\n",
                        name, index, pin->bank, gpio_banks);
                return -EINVAL;
        }

        if (!gpio_chips[pin->bank]) {
                dev_err(info->dev, "%s: pin conf %d bank_id %d not enabled\n",
                        name, index, pin->bank);
                return -ENXIO;
        }

        if (pin->pin >= MAX_NB_GPIO_PER_BANK) {
                dev_err(info->dev, "%s: pin conf %d pin_bank_id %d >= %d\n",
                        name, index, pin->pin, MAX_NB_GPIO_PER_BANK);
                return -EINVAL;
        }

        if (!pin->mux)
                return 0;

        mux = pin->mux - 1;

        if (mux >= info->nmux) {
                dev_err(info->dev, "%s: pin conf %d mux_id %d >= nmux %d\n",
                        name, index, mux, info->nmux);
                return -EINVAL;
        }

        if (!(info->mux_mask[pin->bank * info->nmux + mux] & 1 << pin->pin)) {
                dev_err(info->dev, "%s: pin conf %d mux_id %d not supported for pio%c%d\n",
                        name, index, mux, pin->bank + 'A', pin->pin);
                return -EINVAL;
        }

        return 0;
}

static void at91_mux_gpio_disable(void __iomem *pio, unsigned mask)
{
        writel_relaxed(mask, pio + PIO_PDR);
}

static void at91_mux_gpio_enable(void __iomem *pio, unsigned mask, bool input)
{
        writel_relaxed(mask, pio + PIO_PER);
        writel_relaxed(mask, pio + (input ? PIO_ODR : PIO_OER));
}

static int at91_pmx_set(struct pinctrl_dev *pctldev, unsigned selector,
                        unsigned group)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        const struct at91_pmx_pin *pins_conf = info->groups[group].pins_conf;
        const struct at91_pmx_pin *pin;
        uint32_t npins = info->groups[group].npins;
        int i, ret;
        unsigned mask;
        void __iomem *pio;

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

        /* first check that all the pins of the group are valid with a valid
         * parameter */
        for (i = 0; i < npins; i++) {
                pin = &pins_conf[i];
                ret = pin_check_config(info, info->groups[group].name, i, pin);
                if (ret)
                        return ret;
        }

        for (i = 0; i < npins; i++) {
                pin = &pins_conf[i];
                at91_pin_dbg(info->dev, pin);
                pio = pin_to_controller(info, pin->bank);

                if (!pio)
                        continue;

                mask = pin_to_mask(pin->pin);
                at91_mux_disable_interrupt(pio, mask);
                switch (pin->mux) {
                case AT91_MUX_GPIO:
                        at91_mux_gpio_enable(pio, mask, 1);
                        break;
                case AT91_MUX_PERIPH_A:
                        info->ops->mux_A_periph(pio, mask);
                        break;
                case AT91_MUX_PERIPH_B:
                        info->ops->mux_B_periph(pio, mask);
                        break;
                case AT91_MUX_PERIPH_C:
                        if (!info->ops->mux_C_periph)
                                return -EINVAL;
                        info->ops->mux_C_periph(pio, mask);
                        break;
                case AT91_MUX_PERIPH_D:
                        if (!info->ops->mux_D_periph)
                                return -EINVAL;
                        info->ops->mux_D_periph(pio, mask);
                        break;
                }
                if (pin->mux)
                        at91_mux_gpio_disable(pio, mask);
        }

        return 0;
}

static int at91_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->nfunctions;
}

static const char *at91_pmx_get_func_name(struct pinctrl_dev *pctldev,
                                          unsigned selector)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

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

static int at91_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
                               const char * const **groups,
                               unsigned * const num_groups)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

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

        return 0;
}

static int at91_gpio_request_enable(struct pinctrl_dev *pctldev,
                                    struct pinctrl_gpio_range *range,
                                    unsigned offset)
{
        struct at91_pinctrl *npct = pinctrl_dev_get_drvdata(pctldev);
        struct at91_gpio_chip *at91_chip;
        struct gpio_chip *chip;
        unsigned mask;

        if (!range) {
                dev_err(npct->dev, "invalid range\n");
                return -EINVAL;
        }
        if (!range->gc) {
                dev_err(npct->dev, "missing GPIO chip in range\n");
                return -EINVAL;
        }
        chip = range->gc;
        at91_chip = gpiochip_get_data(chip);

        dev_dbg(npct->dev, "enable pin %u as GPIO\n", offset);

        mask = 1 << (offset - chip->base);

        dev_dbg(npct->dev, "enable pin %u as PIO%c%d 0x%x\n",
                offset, 'A' + range->id, offset - chip->base, mask);

        writel_relaxed(mask, at91_chip->regbase + PIO_PER);

        return 0;
}

static void at91_gpio_disable_free(struct pinctrl_dev *pctldev,
                                   struct pinctrl_gpio_range *range,
                                   unsigned offset)
{
        struct at91_pinctrl *npct = pinctrl_dev_get_drvdata(pctldev);

        dev_dbg(npct->dev, "disable pin %u as GPIO\n", offset);
        /* Set the pin to some default state, GPIO is usually default */
}

static const struct pinmux_ops at91_pmx_ops = {
        .get_functions_count    = at91_pmx_get_funcs_count,
        .get_function_name      = at91_pmx_get_func_name,
        .get_function_groups    = at91_pmx_get_groups,
        .set_mux                = at91_pmx_set,
        .gpio_request_enable    = at91_gpio_request_enable,
        .gpio_disable_free      = at91_gpio_disable_free,
};

static int at91_pinconf_get(struct pinctrl_dev *pctldev,
                             unsigned pin_id, unsigned long *config)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        void __iomem *pio;
        unsigned pin;
        int div;
        bool out;

        *config = 0;
        dev_dbg(info->dev, "%s:%d, pin_id=%d", __func__, __LINE__, pin_id);
        pio = pin_to_controller(info, pin_to_bank(pin_id));

        if (!pio)
                return -EINVAL;

        pin = pin_id % MAX_NB_GPIO_PER_BANK;

        if (at91_mux_get_multidrive(pio, pin))
                *config |= MULTI_DRIVE;

        if (at91_mux_get_pullup(pio, pin))
                *config |= PULL_UP;

        if (info->ops->get_deglitch && info->ops->get_deglitch(pio, pin))
                *config |= DEGLITCH;
        if (info->ops->get_debounce && info->ops->get_debounce(pio, pin, &div))
                *config |= DEBOUNCE | (div << DEBOUNCE_VAL_SHIFT);
        if (info->ops->get_pulldown && info->ops->get_pulldown(pio, pin))
                *config |= PULL_DOWN;
        if (info->ops->get_schmitt_trig && info->ops->get_schmitt_trig(pio, pin))
                *config |= DIS_SCHMIT;
        if (info->ops->get_drivestrength)
                *config |= (info->ops->get_drivestrength(pio, pin)
                                << DRIVE_STRENGTH_SHIFT);
        if (at91_mux_get_output(pio, pin, &out))
                *config |= OUTPUT | (out << OUTPUT_VAL_SHIFT);

        return 0;
}

static int at91_pinconf_set(struct pinctrl_dev *pctldev,
                             unsigned pin_id, unsigned long *configs,
                             unsigned num_configs)
{
        struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        unsigned mask;
        void __iomem *pio;
        int i;
        unsigned long config;
        unsigned pin;

        for (i = 0; i < num_configs; i++) {
                config = configs[i];

                dev_dbg(info->dev,
                        "%s:%d, pin_id=%d, config=0x%lx",
                        __func__, __LINE__, pin_id, config);
                pio = pin_to_controller(info, pin_to_bank(pin_id));

                if (!pio)
                        return -EINVAL;

                pin = pin_id % MAX_NB_GPIO_PER_BANK;
                mask = pin_to_mask(pin);

                if (config & PULL_UP && config & PULL_DOWN)
                        return -EINVAL;

                at91_mux_set_output(pio, mask, config & OUTPUT,
                                    (config & OUTPUT_VAL) >> OUTPUT_VAL_SHIFT);
                at91_mux_set_pullup(pio, mask, config & PULL_UP);
                at91_mux_set_multidrive(pio, mask, config & MULTI_DRIVE);
                if (info->ops->set_deglitch)
                        info->ops->set_deglitch(pio, mask, config & DEGLITCH);
                if (info->ops->set_debounce)
                        info->ops->set_debounce(pio, mask, config & DEBOUNCE,
                                (config & DEBOUNCE_VAL) >> DEBOUNCE_VAL_SHIFT);
                if (info->ops->set_pulldown)
                        info->ops->set_pulldown(pio, mask, config & PULL_DOWN);
                if (info->ops->disable_schmitt_trig && config & DIS_SCHMIT)
                        info->ops->disable_schmitt_trig(pio, mask);
                if (info->ops->set_drivestrength)
                        info->ops->set_drivestrength(pio, pin,
                                (config & DRIVE_STRENGTH)
                                        >> DRIVE_STRENGTH_SHIFT);

        } /* for each config */

        return 0;
}

#define DBG_SHOW_FLAG(flag) do {                \
        if (config & flag) {                    \
                if (num_conf)                   \
                        seq_puts(s, "|");       \
                seq_puts(s, #flag);             \
                num_conf++;                     \
        }                                       \
} while (0)

#define DBG_SHOW_FLAG_MASKED(mask,flag) do {    \
        if ((config & mask) == flag) {          \
                if (num_conf)                   \
                        seq_puts(s, "|");       \
                seq_puts(s, #flag);             \
                num_conf++;                     \
        }                                       \
} while (0)

static void at91_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                                   struct seq_file *s, unsigned pin_id)
{
        unsigned long config;
        int val, num_conf = 0;

        at91_pinconf_get(pctldev, pin_id, &config);

        DBG_SHOW_FLAG(MULTI_DRIVE);
        DBG_SHOW_FLAG(PULL_UP);
        DBG_SHOW_FLAG(PULL_DOWN);
        DBG_SHOW_FLAG(DIS_SCHMIT);
        DBG_SHOW_FLAG(DEGLITCH);
        DBG_SHOW_FLAG_MASKED(DRIVE_STRENGTH, DRIVE_STRENGTH_LOW);
        DBG_SHOW_FLAG_MASKED(DRIVE_STRENGTH, DRIVE_STRENGTH_MED);
        DBG_SHOW_FLAG_MASKED(DRIVE_STRENGTH, DRIVE_STRENGTH_HI);
        DBG_SHOW_FLAG(DEBOUNCE);
        if (config & DEBOUNCE) {
                val = config >> DEBOUNCE_VAL_SHIFT;
                seq_printf(s, "(%d)", val);
        }

        return;
}

static void at91_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
                                         struct seq_file *s, unsigned group)
{
}

static const struct pinconf_ops at91_pinconf_ops = {
        .pin_config_get                 = at91_pinconf_get,
        .pin_config_set                 = at91_pinconf_set,
        .pin_config_dbg_show            = at91_pinconf_dbg_show,
        .pin_config_group_dbg_show      = at91_pinconf_group_dbg_show,
};

static struct pinctrl_desc at91_pinctrl_desc = {
        .pctlops        = &at91_pctrl_ops,
        .pmxops         = &at91_pmx_ops,
        .confops        = &at91_pinconf_ops,
        .owner          = THIS_MODULE,
};

static const char *gpio_compat = "atmel,at91rm9200-gpio";

static void at91_pinctrl_child_count(struct at91_pinctrl *info,
                                     struct device_node *np)
{
        struct device_node *child;

        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, gpio_compat)) {
                        if (of_device_is_available(child))
                                info->nactive_banks++;
                } else {
                        info->nfunctions++;
                        info->ngroups += of_get_child_count(child);
                }
        }
}

static int at91_pinctrl_mux_mask(struct at91_pinctrl *info,
                                 struct device_node *np)
{
        int ret = 0;
        int size;
        const __be32 *list;

        list = of_get_property(np, "atmel,mux-mask", &size);
        if (!list) {
                dev_err(info->dev, "can not read the mux-mask of %d\n", size);
                return -EINVAL;
        }

        size /= sizeof(*list);
        if (!size || size % gpio_banks) {
                dev_err(info->dev, "wrong mux mask array should be by %d\n", gpio_banks);
                return -EINVAL;
        }
        info->nmux = size / gpio_banks;

        info->mux_mask = devm_kcalloc(info->dev, size, sizeof(u32),
                                      GFP_KERNEL);
        if (!info->mux_mask)
                return -ENOMEM;

        ret = of_property_read_u32_array(np, "atmel,mux-mask",
                                          info->mux_mask, size);
        if (ret)
                dev_err(info->dev, "can not read the mux-mask of %d\n", size);
        return ret;
}

static int at91_pinctrl_parse_groups(struct device_node *np,
                                     struct at91_pin_group *grp,
                                     struct at91_pinctrl *info, u32 index)
{
        struct at91_pmx_pin *pin;
        int size;
        const __be32 *list;
        int i, j;

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

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

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

        grp->npins = size / 4;
        pin = grp->pins_conf = devm_kcalloc(info->dev,
                                            grp->npins,
                                            sizeof(struct at91_pmx_pin),
                                            GFP_KERNEL);
        grp->pins = devm_kcalloc(info->dev, grp->npins, sizeof(unsigned int),
                                 GFP_KERNEL);
        if (!grp->pins_conf || !grp->pins)
                return -ENOMEM;

        for (i = 0, j = 0; i < size; i += 4, j++) {
                pin->bank = be32_to_cpu(*list++);
                pin->pin = be32_to_cpu(*list++);
                grp->pins[j] = pin->bank * MAX_NB_GPIO_PER_BANK + pin->pin;
                pin->mux = be32_to_cpu(*list++);
                pin->conf = be32_to_cpu(*list++);

                at91_pin_dbg(info->dev, pin);
                pin++;
        }

        return 0;
}

static int at91_pinctrl_parse_functions(struct device_node *np,
                                        struct at91_pinctrl *info, u32 index)
{
        struct device_node *child;
        struct at91_pmx_func *func;
        struct at91_pin_group *grp;
        int ret;
        static u32 grp_index;
        u32 i = 0;

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

        func = &info->functions[index];

        /* Initialise function */
        func->name = np->name;
        func->ngroups = of_get_child_count(np);
        if (func->ngroups == 0) {
                dev_err(info->dev, "no groups defined\n");
                return -EINVAL;
        }
        func->groups = devm_kcalloc(info->dev,
                        func->ngroups, sizeof(char *), GFP_KERNEL);
        if (!func->groups)
                return -ENOMEM;

        for_each_child_of_node(np, child) {
                func->groups[i] = child->name;
                grp = &info->groups[grp_index++];
                ret = at91_pinctrl_parse_groups(child, grp, info, i++);
                if (ret) {
                        of_node_put(child);
                        return ret;
                }
        }

        return 0;
}

static const struct of_device_id at91_pinctrl_of_match[] = {
        { .compatible = "atmel,sama5d3-pinctrl", .data = &sama5d3_ops },
        { .compatible = "atmel,at91sam9x5-pinctrl", .data = &at91sam9x5_ops },
        { .compatible = "atmel,at91rm9200-pinctrl", .data = &at91rm9200_ops },
        { /* sentinel */ }
};

static int at91_pinctrl_probe_dt(struct platform_device *pdev,
                                 struct at91_pinctrl *info)
{
        int ret = 0;
        int i, j;
        uint32_t *tmp;
        struct device_node *np = pdev->dev.of_node;
        struct device_node *child;

        if (!np)
                return -ENODEV;

        info->dev = &pdev->dev;
        info->ops = (struct at91_pinctrl_mux_ops *)
                of_match_device(at91_pinctrl_of_match, &pdev->dev)->data;
        at91_pinctrl_child_count(info, np);

        if (gpio_banks < 1) {
                dev_err(&pdev->dev, "you need to specify at least one gpio-controller\n");
                return -EINVAL;
        }

        ret = at91_pinctrl_mux_mask(info, np);
        if (ret)
                return ret;

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

        dev_dbg(&pdev->dev, "mux-mask\n");
        tmp = info->mux_mask;
        for (i = 0; i < gpio_banks; i++) {
                for (j = 0; j < info->nmux; j++, tmp++) {
                        dev_dbg(&pdev->dev, "%d:%d\t0x%x\n", i, j, tmp[0]);
                }
        }

        dev_dbg(&pdev->dev, "nfunctions = %d\n", info->nfunctions);
        dev_dbg(&pdev->dev, "ngroups = %d\n", info->ngroups);
        info->functions = devm_kcalloc(&pdev->dev,
                                        info->nfunctions,
                                        sizeof(struct at91_pmx_func),
                                        GFP_KERNEL);
        if (!info->functions)
                return -ENOMEM;

        info->groups = devm_kcalloc(&pdev->dev,
                                        info->ngroups,
                                        sizeof(struct at91_pin_group),
                                        GFP_KERNEL);
        if (!info->groups)
                return -ENOMEM;

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

        i = 0;

        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, gpio_compat))
                        continue;
                ret = at91_pinctrl_parse_functions(child, info, i++);
                if (ret) {
                        dev_err(&pdev->dev, "failed to parse function\n");
                        of_node_put(child);
                        return ret;
                }
        }

        return 0;
}

static int at91_pinctrl_probe(struct platform_device *pdev)
{
        struct at91_pinctrl *info;
        struct pinctrl_pin_desc *pdesc;
        int ret, i, j, k, ngpio_chips_enabled = 0;

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

        ret = at91_pinctrl_probe_dt(pdev, info);
        if (ret)
                return ret;

        /*
         * We need all the GPIO drivers to probe FIRST, or we will not be able
         * to obtain references to the struct gpio_chip * for them, and we
         * need this to proceed.
         */
        for (i = 0; i < gpio_banks; i++)
                if (gpio_chips[i])
                        ngpio_chips_enabled++;

        if (ngpio_chips_enabled < info->nactive_banks) {
                dev_warn(&pdev->dev,
                         "All GPIO chips are not registered yet (%d/%d)\n",
                         ngpio_chips_enabled, info->nactive_banks);
                devm_kfree(&pdev->dev, info);
                return -EPROBE_DEFER;
        }

        at91_pinctrl_desc.name = dev_name(&pdev->dev);
        at91_pinctrl_desc.npins = gpio_banks * MAX_NB_GPIO_PER_BANK;
        at91_pinctrl_desc.pins = pdesc =
                devm_kcalloc(&pdev->dev,
                             at91_pinctrl_desc.npins, sizeof(*pdesc),
                             GFP_KERNEL);

        if (!at91_pinctrl_desc.pins)
                return -ENOMEM;

        for (i = 0, k = 0; i < gpio_banks; i++) {
                for (j = 0; j < MAX_NB_GPIO_PER_BANK; j++, k++) {
                        pdesc->number = k;
                        pdesc->name = kasprintf(GFP_KERNEL, "pio%c%d", i + 'A', j);
                        pdesc++;
                }
        }

        platform_set_drvdata(pdev, info);
        info->pctl = devm_pinctrl_register(&pdev->dev, &at91_pinctrl_desc,
                                           info);

        if (IS_ERR(info->pctl)) {
                dev_err(&pdev->dev, "could not register AT91 pinctrl driver\n");
                return PTR_ERR(info->pctl);
        }

        /* We will handle a range of GPIO pins */
        for (i = 0; i < gpio_banks; i++)
                if (gpio_chips[i])
                        pinctrl_add_gpio_range(info->pctl, &gpio_chips[i]->range);

        dev_info(&pdev->dev, "initialized AT91 pinctrl driver\n");

        return 0;
}

static int at91_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;
        unsigned mask = 1 << offset;
        u32 osr;

        osr = readl_relaxed(pio + PIO_OSR);
        return !(osr & mask);
}

static int at91_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;
        unsigned mask = 1 << offset;

        writel_relaxed(mask, pio + PIO_ODR);
        return 0;
}

static int at91_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;
        unsigned mask = 1 << offset;
        u32 pdsr;

        pdsr = readl_relaxed(pio + PIO_PDSR);
        return (pdsr & mask) != 0;
}

static void at91_gpio_set(struct gpio_chip *chip, unsigned offset,
                                int val)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;
        unsigned mask = 1 << offset;

        writel_relaxed(mask, pio + (val ? PIO_SODR : PIO_CODR));
}

static void at91_gpio_set_multiple(struct gpio_chip *chip,
                                      unsigned long *mask, unsigned long *bits)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;

#define BITS_MASK(bits) (((bits) == 32) ? ~0U : (BIT(bits) - 1))
        /* Mask additionally to ngpio as not all GPIO controllers have 32 pins */
        uint32_t set_mask = (*mask & *bits) & BITS_MASK(chip->ngpio);
        uint32_t clear_mask = (*mask & ~(*bits)) & BITS_MASK(chip->ngpio);

        writel_relaxed(set_mask, pio + PIO_SODR);
        writel_relaxed(clear_mask, pio + PIO_CODR);
}

static int at91_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
                                int val)
{
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;
        unsigned mask = 1 << offset;

        writel_relaxed(mask, pio + (val ? PIO_SODR : PIO_CODR));
        writel_relaxed(mask, pio + PIO_OER);

        return 0;
}

#ifdef CONFIG_DEBUG_FS
static void at91_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
        enum at91_mux mode;
        int i;
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(chip);
        void __iomem *pio = at91_gpio->regbase;

        for (i = 0; i < chip->ngpio; i++) {
                unsigned mask = pin_to_mask(i);
                const char *gpio_label;

                gpio_label = gpiochip_is_requested(chip, i);
                if (!gpio_label)
                        continue;
                mode = at91_gpio->ops->get_periph(pio, mask);
                seq_printf(s, "[%s] GPIO%s%d: ",
                           gpio_label, chip->label, i);
                if (mode == AT91_MUX_GPIO) {
                        seq_printf(s, "[gpio] ");
                        seq_printf(s, "%s ",
                                      readl_relaxed(pio + PIO_OSR) & mask ?
                                      "output" : "input");
                        seq_printf(s, "%s\n",
                                      readl_relaxed(pio + PIO_PDSR) & mask ?
                                      "set" : "clear");
                } else {
                        seq_printf(s, "[periph %c]\n",
                                   mode + 'A' - 1);
                }
        }
}
#else
#define at91_gpio_dbg_show      NULL
#endif

/* Several AIC controller irqs are dispatched through this GPIO handler.
 * To use any AT91_PIN_* as an externally triggered IRQ, first call
 * at91_set_gpio_input() then maybe enable its glitch filter.
 * Then just request_irq() with the pin ID; it works like any ARM IRQ
 * handler.
 * First implementation always triggers on rising and falling edges
 * whereas the newer PIO3 can be additionally configured to trigger on
 * level, edge with any polarity.
 *
 * Alternatively, certain pins may be used directly as IRQ0..IRQ6 after
 * configuring them with at91_set_a_periph() or at91_set_b_periph().
 * IRQ0..IRQ6 should be configurable, e.g. level vs edge triggering.
 */

static void gpio_irq_mask(struct irq_data *d)
{
        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
        void __iomem    *pio = at91_gpio->regbase;
        unsigned        mask = 1 << d->hwirq;

        if (pio)
                writel_relaxed(mask, pio + PIO_IDR);
}

static void gpio_irq_unmask(struct irq_data *d)
{
        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
        void __iomem    *pio = at91_gpio->regbase;
        unsigned        mask = 1 << d->hwirq;

        if (pio)
                writel_relaxed(mask, pio + PIO_IER);
}

static int gpio_irq_type(struct irq_data *d, unsigned type)
{
        switch (type) {
        case IRQ_TYPE_NONE:
        case IRQ_TYPE_EDGE_BOTH:
                return 0;
        default:
                return -EINVAL;
        }
}

/* Alternate irq type for PIO3 support */
static int alt_gpio_irq_type(struct irq_data *d, unsigned type)
{
        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
        void __iomem    *pio = at91_gpio->regbase;
        unsigned        mask = 1 << d->hwirq;

        switch (type) {
        case IRQ_TYPE_EDGE_RISING:
                irq_set_handler_locked(d, handle_simple_irq);
                writel_relaxed(mask, pio + PIO_ESR);
                writel_relaxed(mask, pio + PIO_REHLSR);
                break;
        case IRQ_TYPE_EDGE_FALLING:
                irq_set_handler_locked(d, handle_simple_irq);
                writel_relaxed(mask, pio + PIO_ESR);
                writel_relaxed(mask, pio + PIO_FELLSR);
                break;
        case IRQ_TYPE_LEVEL_LOW:
                irq_set_handler_locked(d, handle_level_irq);
                writel_relaxed(mask, pio + PIO_LSR);
                writel_relaxed(mask, pio + PIO_FELLSR);
                break;
        case IRQ_TYPE_LEVEL_HIGH:
                irq_set_handler_locked(d, handle_level_irq);
                writel_relaxed(mask, pio + PIO_LSR);
                writel_relaxed(mask, pio + PIO_REHLSR);
                break;
        case IRQ_TYPE_EDGE_BOTH:
                /*
                 * disable additional interrupt modes:
                 * fall back to default behavior
                 */
                irq_set_handler_locked(d, handle_simple_irq);
                writel_relaxed(mask, pio + PIO_AIMDR);
                return 0;
        case IRQ_TYPE_NONE:
        default:
                pr_warn("AT91: No type for irq %d\n", gpio_to_irq(d->irq));
                return -EINVAL;
        }

        /* enable additional interrupt modes */
        writel_relaxed(mask, pio + PIO_AIMER);

        return 0;
}

static void gpio_irq_ack(struct irq_data *d)
{
        /* the interrupt is already cleared before by reading ISR */
}

#ifdef CONFIG_PM

static u32 wakeups[MAX_GPIO_BANKS];
static u32 backups[MAX_GPIO_BANKS];

static int gpio_irq_set_wake(struct irq_data *d, unsigned state)
{
        struct at91_gpio_chip *at91_gpio = irq_data_get_irq_chip_data(d);
        unsigned        bank = at91_gpio->pioc_idx;
        unsigned mask = 1 << d->hwirq;

        if (unlikely(bank >= MAX_GPIO_BANKS))
                return -EINVAL;

        if (state)
                wakeups[bank] |= mask;
        else
                wakeups[bank] &= ~mask;

        irq_set_irq_wake(at91_gpio->pioc_virq, state);

        return 0;
}

void at91_pinctrl_gpio_suspend(void)
{
        int i;

        for (i = 0; i < gpio_banks; i++) {
                void __iomem  *pio;

                if (!gpio_chips[i])
                        continue;

                pio = gpio_chips[i]->regbase;

                backups[i] = readl_relaxed(pio + PIO_IMR);
                writel_relaxed(backups[i], pio + PIO_IDR);
                writel_relaxed(wakeups[i], pio + PIO_IER);

                if (!wakeups[i])
                        clk_disable_unprepare(gpio_chips[i]->clock);
                else
                        printk(KERN_DEBUG "GPIO-%c may wake for %08x\n",
                               'A'+i, wakeups[i]);
        }
}

void at91_pinctrl_gpio_resume(void)
{
        int i;

        for (i = 0; i < gpio_banks; i++) {
                void __iomem  *pio;

                if (!gpio_chips[i])
                        continue;

                pio = gpio_chips[i]->regbase;

                if (!wakeups[i])
                        clk_prepare_enable(gpio_chips[i]->clock);

                writel_relaxed(wakeups[i], pio + PIO_IDR);
                writel_relaxed(backups[i], pio + PIO_IER);
        }
}

#else
#define gpio_irq_set_wake       NULL
#endif /* CONFIG_PM */

static struct irq_chip gpio_irqchip = {
        .name           = "GPIO",
        .irq_ack        = gpio_irq_ack,
        .irq_disable    = gpio_irq_mask,
        .irq_mask       = gpio_irq_mask,
        .irq_unmask     = gpio_irq_unmask,
        /* .irq_set_type is set dynamically */
        .irq_set_wake   = gpio_irq_set_wake,
};

static void gpio_irq_handler(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct gpio_chip *gpio_chip = irq_desc_get_handler_data(desc);
        struct at91_gpio_chip *at91_gpio = gpiochip_get_data(gpio_chip);
        void __iomem    *pio = at91_gpio->regbase;
        unsigned long   isr;
        int             n;

        chained_irq_enter(chip, desc);
        for (;;) {
                /* Reading ISR acks pending (edge triggered) GPIO interrupts.
                 * When there are none pending, we're finished unless we need
                 * to process multiple banks (like ID_PIOCDE on sam9263).
                 */
                isr = readl_relaxed(pio + PIO_ISR) & readl_relaxed(pio + PIO_IMR);
                if (!isr) {
                        if (!at91_gpio->next)
                                break;
                        at91_gpio = at91_gpio->next;
                        pio = at91_gpio->regbase;
                        gpio_chip = &at91_gpio->chip;
                        continue;
                }

                for_each_set_bit(n, &isr, BITS_PER_LONG) {
                        generic_handle_irq(irq_find_mapping(
                                           gpio_chip->irq.domain, n));
                }
        }
        chained_irq_exit(chip, desc);
        /* now it may re-trigger */
}

static int at91_gpio_of_irq_setup(struct platform_device *pdev,
                                  struct at91_gpio_chip *at91_gpio)
{
        struct gpio_chip        *gpiochip_prev = NULL;
        struct at91_gpio_chip   *prev = NULL;
        struct irq_data         *d = irq_get_irq_data(at91_gpio->pioc_virq);
        int ret, i;

        at91_gpio->pioc_hwirq = irqd_to_hwirq(d);

        /* Setup proper .irq_set_type function */
        gpio_irqchip.irq_set_type = at91_gpio->ops->irq_type;

        /* Disable irqs of this PIO controller */
        writel_relaxed(~0, at91_gpio->regbase + PIO_IDR);

        /*
         * Let the generic code handle this edge IRQ, the the chained
         * handler will perform the actual work of handling the parent
         * interrupt.
         */
        ret = gpiochip_irqchip_add(&at91_gpio->chip,
                                   &gpio_irqchip,
                                   0,
                                   handle_edge_irq,
                                   IRQ_TYPE_NONE);
        if (ret) {
                dev_err(&pdev->dev, "at91_gpio.%d: Couldn't add irqchip to gpiochip.\n",
                        at91_gpio->pioc_idx);
                return ret;
        }

        /* The top level handler handles one bank of GPIOs, except
         * on some SoC it can handle up to three...
         * We only set up the handler for the first of the list.
         */
        gpiochip_prev = irq_get_handler_data(at91_gpio->pioc_virq);
        if (!gpiochip_prev) {
                /* Then register the chain on the parent IRQ */
                gpiochip_set_chained_irqchip(&at91_gpio->chip,
                                             &gpio_irqchip,
                                             at91_gpio->pioc_virq,
                                             gpio_irq_handler);
                return 0;
        }

        prev = gpiochip_get_data(gpiochip_prev);

        /* we can only have 2 banks before */
        for (i = 0; i < 2; i++) {
                if (prev->next) {
                        prev = prev->next;
                } else {
                        prev->next = at91_gpio;
                        return 0;
                }
        }

        return -EINVAL;
}

/* This structure is replicated for each GPIO block allocated at probe time */
static const struct gpio_chip at91_gpio_template = {
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .get_direction          = at91_gpio_get_direction,
        .direction_input        = at91_gpio_direction_input,
        .get                    = at91_gpio_get,
        .direction_output       = at91_gpio_direction_output,
        .set                    = at91_gpio_set,
        .set_multiple           = at91_gpio_set_multiple,
        .dbg_show               = at91_gpio_dbg_show,
        .can_sleep              = false,
        .ngpio                  = MAX_NB_GPIO_PER_BANK,
};

static const struct of_device_id at91_gpio_of_match[] = {
        { .compatible = "atmel,at91sam9x5-gpio", .data = &at91sam9x5_ops, },
        { .compatible = "atmel,at91rm9200-gpio", .data = &at91rm9200_ops },
        { /* sentinel */ }
};

static int at91_gpio_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct resource *res;
        struct at91_gpio_chip *at91_chip = NULL;
        struct gpio_chip *chip;
        struct pinctrl_gpio_range *range;
        int ret = 0;
        int irq, i;
        int alias_idx = of_alias_get_id(np, "gpio");
        uint32_t ngpio;
        char **names;

        BUG_ON(alias_idx >= ARRAY_SIZE(gpio_chips));
        if (gpio_chips[alias_idx]) {
                ret = -EBUSY;
                goto err;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                ret = irq;
                goto err;
        }

        at91_chip = devm_kzalloc(&pdev->dev, sizeof(*at91_chip), GFP_KERNEL);
        if (!at91_chip) {
                ret = -ENOMEM;
                goto err;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        at91_chip->regbase = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(at91_chip->regbase)) {
                ret = PTR_ERR(at91_chip->regbase);
                goto err;
        }

        at91_chip->ops = (struct at91_pinctrl_mux_ops *)
                of_match_device(at91_gpio_of_match, &pdev->dev)->data;
        at91_chip->pioc_virq = irq;
        at91_chip->pioc_idx = alias_idx;

        at91_chip->clock = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(at91_chip->clock)) {
                dev_err(&pdev->dev, "failed to get clock, ignoring.\n");
                ret = PTR_ERR(at91_chip->clock);
                goto err;
        }

        ret = clk_prepare_enable(at91_chip->clock);
        if (ret) {
                dev_err(&pdev->dev, "failed to prepare and enable clock, ignoring.\n");
                goto clk_enable_err;
        }

        at91_chip->chip = at91_gpio_template;

        chip = &at91_chip->chip;
        chip->of_node = np;
        chip->label = dev_name(&pdev->dev);
        chip->parent = &pdev->dev;
        chip->owner = THIS_MODULE;
        chip->base = alias_idx * MAX_NB_GPIO_PER_BANK;

        if (!of_property_read_u32(np, "#gpio-lines", &ngpio)) {
                if (ngpio >= MAX_NB_GPIO_PER_BANK)
                        pr_err("at91_gpio.%d, gpio-nb >= %d failback to %d\n",
                               alias_idx, MAX_NB_GPIO_PER_BANK, MAX_NB_GPIO_PER_BANK);
                else
                        chip->ngpio = ngpio;
        }

        names = devm_kcalloc(&pdev->dev, chip->ngpio, sizeof(char *),
                             GFP_KERNEL);

        if (!names) {
                ret = -ENOMEM;
                goto clk_enable_err;
        }

        for (i = 0; i < chip->ngpio; i++)
                names[i] = kasprintf(GFP_KERNEL, "pio%c%d", alias_idx + 'A', i);

        chip->names = (const char *const *)names;

        range = &at91_chip->range;
        range->name = chip->label;
        range->id = alias_idx;
        range->pin_base = range->base = range->id * MAX_NB_GPIO_PER_BANK;

        range->npins = chip->ngpio;
        range->gc = chip;

        ret = gpiochip_add_data(chip, at91_chip);
        if (ret)
                goto gpiochip_add_err;

        gpio_chips[alias_idx] = at91_chip;
        gpio_banks = max(gpio_banks, alias_idx + 1);

        ret = at91_gpio_of_irq_setup(pdev, at91_chip);
        if (ret)
                goto irq_setup_err;

        dev_info(&pdev->dev, "at address %p\n", at91_chip->regbase);

        return 0;

irq_setup_err:
        gpiochip_remove(chip);
gpiochip_add_err:
clk_enable_err:
        clk_disable_unprepare(at91_chip->clock);
err:
        dev_err(&pdev->dev, "Failure %i for GPIO %i\n", ret, alias_idx);

        return ret;
}

static struct platform_driver at91_gpio_driver = {
        .driver = {
                .name = "gpio-at91",
                .of_match_table = at91_gpio_of_match,
        },
        .probe = at91_gpio_probe,
};

static struct platform_driver at91_pinctrl_driver = {
        .driver = {
                .name = "pinctrl-at91",
                .of_match_table = at91_pinctrl_of_match,
        },
        .probe = at91_pinctrl_probe,
};

static struct platform_driver * const drivers[] = {
        &at91_gpio_driver,
        &at91_pinctrl_driver,
};

static int __init at91_pinctrl_init(void)
{
        return platform_register_drivers(drivers, ARRAY_SIZE(drivers));
}
arch_initcall(at91_pinctrl_init);