// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 STMicroelectronics (R&D) Limited.
 * Authors:
 *      Srinivas Kandagatla <srinivas.kandagatla@st.com>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h> /* of_get_named_gpio() */
#include <linux/of_address.h>
#include <linux/gpio/driver.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/platform_device.h>
#include "core.h"

/* PIO Block registers */
/* PIO output */
#define REG_PIO_POUT                    0x00
/* Set bits of POUT */
#define REG_PIO_SET_POUT                0x04
/* Clear bits of POUT */
#define REG_PIO_CLR_POUT                0x08
/* PIO input */
#define REG_PIO_PIN                     0x10
/* PIO configuration */
#define REG_PIO_PC(n)                   (0x20 + (n) * 0x10)
/* Set bits of PC[2:0] */
#define REG_PIO_SET_PC(n)               (0x24 + (n) * 0x10)
/* Clear bits of PC[2:0] */
#define REG_PIO_CLR_PC(n)               (0x28 + (n) * 0x10)
/* PIO input comparison */
#define REG_PIO_PCOMP                   0x50
/* Set bits of PCOMP */
#define REG_PIO_SET_PCOMP               0x54
/* Clear bits of PCOMP */
#define REG_PIO_CLR_PCOMP               0x58
/* PIO input comparison mask */
#define REG_PIO_PMASK                   0x60
/* Set bits of PMASK */
#define REG_PIO_SET_PMASK               0x64
/* Clear bits of PMASK */
#define REG_PIO_CLR_PMASK               0x68

#define ST_GPIO_DIRECTION_BIDIR 0x1
#define ST_GPIO_DIRECTION_OUT   0x2
#define ST_GPIO_DIRECTION_IN    0x4

/**
 *  Packed style retime configuration.
 *  There are two registers cfg0 and cfg1 in this style for each bank.
 *  Each field in this register is 8 bit corresponding to 8 pins in the bank.
 */
#define RT_P_CFGS_PER_BANK                      2
#define RT_P_CFG0_CLK1NOTCLK0_FIELD(reg)        REG_FIELD(reg, 0, 7)
#define RT_P_CFG0_DELAY_0_FIELD(reg)            REG_FIELD(reg, 16, 23)
#define RT_P_CFG0_DELAY_1_FIELD(reg)            REG_FIELD(reg, 24, 31)
#define RT_P_CFG1_INVERTCLK_FIELD(reg)          REG_FIELD(reg, 0, 7)
#define RT_P_CFG1_RETIME_FIELD(reg)             REG_FIELD(reg, 8, 15)
#define RT_P_CFG1_CLKNOTDATA_FIELD(reg)         REG_FIELD(reg, 16, 23)
#define RT_P_CFG1_DOUBLE_EDGE_FIELD(reg)        REG_FIELD(reg, 24, 31)

/**
 * Dedicated style retime Configuration register
 * each register is dedicated per pin.
 */
#define RT_D_CFGS_PER_BANK              8
#define RT_D_CFG_CLK_SHIFT              0
#define RT_D_CFG_CLK_MASK               (0x3 << 0)
#define RT_D_CFG_CLKNOTDATA_SHIFT       2
#define RT_D_CFG_CLKNOTDATA_MASK        BIT(2)
#define RT_D_CFG_DELAY_SHIFT            3
#define RT_D_CFG_DELAY_MASK             (0xf << 3)
#define RT_D_CFG_DELAY_INNOTOUT_SHIFT   7
#define RT_D_CFG_DELAY_INNOTOUT_MASK    BIT(7)
#define RT_D_CFG_DOUBLE_EDGE_SHIFT      8
#define RT_D_CFG_DOUBLE_EDGE_MASK       BIT(8)
#define RT_D_CFG_INVERTCLK_SHIFT        9
#define RT_D_CFG_INVERTCLK_MASK         BIT(9)
#define RT_D_CFG_RETIME_SHIFT           10
#define RT_D_CFG_RETIME_MASK            BIT(10)

/*
 * Pinconf is represented in an opaque unsigned long variable.
 * Below is the bit allocation details for each possible configuration.
 * All the bit fields can be encapsulated into four variables
 * (direction, retime-type, retime-clk, retime-delay)
 *
 *       +----------------+
 *[31:28]| reserved-3     |
 *       +----------------+-------------
 *[27]   |      oe        |             |
 *       +----------------+             v
 *[26]   |      pu        |     [Direction      ]
 *       +----------------+             ^
 *[25]   |      od        |             |
 *       +----------------+-------------
 *[24]   | reserved-2     |
 *       +----------------+-------------
 *[23]   |    retime      |             |
 *       +----------------+             |
 *[22]   | retime-invclk  |             |
 *       +----------------+             v
 *[21]   |retime-clknotdat|     [Retime-type    ]
 *       +----------------+             ^
 *[20]   | retime-de      |             |
 *       +----------------+-------------
 *[19:18]| retime-clk     |------>[Retime-Clk   ]
 *       +----------------+
 *[17:16]|  reserved-1    |
 *       +----------------+
 *[15..0]| retime-delay   |------>[Retime Delay]
 *       +----------------+
 */

#define ST_PINCONF_UNPACK(conf, param)\
                                ((conf >> ST_PINCONF_ ##param ##_SHIFT) \
                                & ST_PINCONF_ ##param ##_MASK)

#define ST_PINCONF_PACK(conf, val, param)       (conf |=\
                                ((val & ST_PINCONF_ ##param ##_MASK) << \
                                        ST_PINCONF_ ##param ##_SHIFT))

/* Output enable */
#define ST_PINCONF_OE_MASK              0x1
#define ST_PINCONF_OE_SHIFT             27
#define ST_PINCONF_OE                   BIT(27)
#define ST_PINCONF_UNPACK_OE(conf)      ST_PINCONF_UNPACK(conf, OE)
#define ST_PINCONF_PACK_OE(conf)        ST_PINCONF_PACK(conf, 1, OE)

/* Pull Up */
#define ST_PINCONF_PU_MASK              0x1
#define ST_PINCONF_PU_SHIFT             26
#define ST_PINCONF_PU                   BIT(26)
#define ST_PINCONF_UNPACK_PU(conf)      ST_PINCONF_UNPACK(conf, PU)
#define ST_PINCONF_PACK_PU(conf)        ST_PINCONF_PACK(conf, 1, PU)

/* Open Drain */
#define ST_PINCONF_OD_MASK              0x1
#define ST_PINCONF_OD_SHIFT             25
#define ST_PINCONF_OD                   BIT(25)
#define ST_PINCONF_UNPACK_OD(conf)      ST_PINCONF_UNPACK(conf, OD)
#define ST_PINCONF_PACK_OD(conf)        ST_PINCONF_PACK(conf, 1, OD)

#define ST_PINCONF_RT_MASK              0x1
#define ST_PINCONF_RT_SHIFT             23
#define ST_PINCONF_RT                   BIT(23)
#define ST_PINCONF_UNPACK_RT(conf)      ST_PINCONF_UNPACK(conf, RT)
#define ST_PINCONF_PACK_RT(conf)        ST_PINCONF_PACK(conf, 1, RT)

#define ST_PINCONF_RT_INVERTCLK_MASK    0x1
#define ST_PINCONF_RT_INVERTCLK_SHIFT   22
#define ST_PINCONF_RT_INVERTCLK         BIT(22)
#define ST_PINCONF_UNPACK_RT_INVERTCLK(conf) \
                        ST_PINCONF_UNPACK(conf, RT_INVERTCLK)
#define ST_PINCONF_PACK_RT_INVERTCLK(conf) \
                        ST_PINCONF_PACK(conf, 1, RT_INVERTCLK)

#define ST_PINCONF_RT_CLKNOTDATA_MASK   0x1
#define ST_PINCONF_RT_CLKNOTDATA_SHIFT  21
#define ST_PINCONF_RT_CLKNOTDATA        BIT(21)
#define ST_PINCONF_UNPACK_RT_CLKNOTDATA(conf)   \
                                ST_PINCONF_UNPACK(conf, RT_CLKNOTDATA)
#define ST_PINCONF_PACK_RT_CLKNOTDATA(conf) \
                                ST_PINCONF_PACK(conf, 1, RT_CLKNOTDATA)

#define ST_PINCONF_RT_DOUBLE_EDGE_MASK  0x1
#define ST_PINCONF_RT_DOUBLE_EDGE_SHIFT 20
#define ST_PINCONF_RT_DOUBLE_EDGE       BIT(20)
#define ST_PINCONF_UNPACK_RT_DOUBLE_EDGE(conf) \
                                ST_PINCONF_UNPACK(conf, RT_DOUBLE_EDGE)
#define ST_PINCONF_PACK_RT_DOUBLE_EDGE(conf) \
                                ST_PINCONF_PACK(conf, 1, RT_DOUBLE_EDGE)

#define ST_PINCONF_RT_CLK_MASK          0x3
#define ST_PINCONF_RT_CLK_SHIFT         18
#define ST_PINCONF_RT_CLK               BIT(18)
#define ST_PINCONF_UNPACK_RT_CLK(conf)  ST_PINCONF_UNPACK(conf, RT_CLK)
#define ST_PINCONF_PACK_RT_CLK(conf, val) ST_PINCONF_PACK(conf, val, RT_CLK)

/* RETIME_DELAY in Pico Secs */
#define ST_PINCONF_RT_DELAY_MASK        0xffff
#define ST_PINCONF_RT_DELAY_SHIFT       0
#define ST_PINCONF_UNPACK_RT_DELAY(conf) ST_PINCONF_UNPACK(conf, RT_DELAY)
#define ST_PINCONF_PACK_RT_DELAY(conf, val) \
                                ST_PINCONF_PACK(conf, val, RT_DELAY)

#define ST_GPIO_PINS_PER_BANK   (8)
#define OF_GPIO_ARGS_MIN        (4)
#define OF_RT_ARGS_MIN          (2)

#define gpio_range_to_bank(chip) \
                container_of(chip, struct st_gpio_bank, range)

#define pc_to_bank(pc) \
                container_of(pc, struct st_gpio_bank, pc)

enum st_retime_style {
        st_retime_style_none,
        st_retime_style_packed,
        st_retime_style_dedicated,
};

struct st_retime_dedicated {
        struct regmap_field *rt[ST_GPIO_PINS_PER_BANK];
};

struct st_retime_packed {
        struct regmap_field *clk1notclk0;
        struct regmap_field *delay_0;
        struct regmap_field *delay_1;
        struct regmap_field *invertclk;
        struct regmap_field *retime;
        struct regmap_field *clknotdata;
        struct regmap_field *double_edge;
};

struct st_pio_control {
        u32 rt_pin_mask;
        struct regmap_field *alt, *oe, *pu, *od;
        /* retiming */
        union {
                struct st_retime_packed         rt_p;
                struct st_retime_dedicated      rt_d;
        } rt;
};

struct st_pctl_data {
        const enum st_retime_style      rt_style;
        const unsigned int              *input_delays;
        const int                       ninput_delays;
        const unsigned int              *output_delays;
        const int                       noutput_delays;
        /* register offset information */
        const int alt, oe, pu, od, rt;
};

struct st_pinconf {
        int             pin;
        const char      *name;
        unsigned long   config;
        int             altfunc;
};

struct st_pmx_func {
        const char      *name;
        const char      **groups;
        unsigned        ngroups;
};

struct st_pctl_group {
        const char              *name;
        unsigned int            *pins;
        unsigned                npins;
        struct st_pinconf       *pin_conf;
};

/*
 * Edge triggers are not supported at hardware level, it is supported by
 * software by exploiting the level trigger support in hardware.
 * Software uses a virtual register (EDGE_CONF) for edge trigger configuration
 * of each gpio pin in a GPIO bank.
 *
 * Each bank has a 32 bit EDGE_CONF register which is divided in to 8 parts of
 * 4-bits. Each 4-bit space is allocated for each pin in a gpio bank.
 *
 * bit allocation per pin is:
 * Bits:  [0 - 3] | [4 - 7]  [8 - 11] ... ... ... ...  [ 28 - 31]
 *       --------------------------------------------------------
 *       |  pin-0  |  pin-2 | pin-3  | ... ... ... ... | pin -7 |
 *       --------------------------------------------------------
 *
 *  A pin can have one of following the values in its edge configuration field.
 *
 *      -------   ----------------------------
 *      [0-3]   - Description
 *      -------   ----------------------------
 *      0000    - No edge IRQ.
 *      0001    - Falling edge IRQ.
 *      0010    - Rising edge IRQ.
 *      0011    - Rising and Falling edge IRQ.
 *      -------   ----------------------------
 */

#define ST_IRQ_EDGE_CONF_BITS_PER_PIN   4
#define ST_IRQ_EDGE_MASK                0xf
#define ST_IRQ_EDGE_FALLING             BIT(0)
#define ST_IRQ_EDGE_RISING              BIT(1)
#define ST_IRQ_EDGE_BOTH                (BIT(0) | BIT(1))

#define ST_IRQ_RISING_EDGE_CONF(pin) \
        (ST_IRQ_EDGE_RISING << (pin * ST_IRQ_EDGE_CONF_BITS_PER_PIN))

#define ST_IRQ_FALLING_EDGE_CONF(pin) \
        (ST_IRQ_EDGE_FALLING << (pin * ST_IRQ_EDGE_CONF_BITS_PER_PIN))

#define ST_IRQ_BOTH_EDGE_CONF(pin) \
        (ST_IRQ_EDGE_BOTH << (pin * ST_IRQ_EDGE_CONF_BITS_PER_PIN))

#define ST_IRQ_EDGE_CONF(conf, pin) \
        (conf >> (pin * ST_IRQ_EDGE_CONF_BITS_PER_PIN) & ST_IRQ_EDGE_MASK)

struct st_gpio_bank {
        struct gpio_chip                gpio_chip;
        struct pinctrl_gpio_range       range;
        void __iomem                    *base;
        struct st_pio_control           pc;
        unsigned long                   irq_edge_conf;
        spinlock_t                      lock;
};

struct st_pinctrl {
        struct device                   *dev;
        struct pinctrl_dev              *pctl;
        struct st_gpio_bank             *banks;
        int                             nbanks;
        struct st_pmx_func              *functions;
        int                             nfunctions;
        struct st_pctl_group            *groups;
        int                             ngroups;
        struct regmap                   *regmap;
        const struct st_pctl_data       *data;
        void __iomem                    *irqmux_base;
};

/* SOC specific data */

static const unsigned int stih407_delays[] = {0, 300, 500, 750, 1000, 1250,
                        1500, 1750, 2000, 2250, 2500, 2750, 3000, 3250 };

static const struct st_pctl_data  stih407_data = {
        .rt_style       = st_retime_style_dedicated,
        .input_delays   = stih407_delays,
        .ninput_delays  = ARRAY_SIZE(stih407_delays),
        .output_delays  = stih407_delays,
        .noutput_delays = ARRAY_SIZE(stih407_delays),
        .alt = 0, .oe = 40, .pu = 50, .od = 60, .rt = 100,
};

static const struct st_pctl_data stih407_flashdata = {
        .rt_style       = st_retime_style_none,
        .input_delays   = stih407_delays,
        .ninput_delays  = ARRAY_SIZE(stih407_delays),
        .output_delays  = stih407_delays,
        .noutput_delays = ARRAY_SIZE(stih407_delays),
        .alt = 0,
        .oe = -1, /* Not Available */
        .pu = -1, /* Not Available */
        .od = 60,
        .rt = 100,
};

static struct st_pio_control *st_get_pio_control(
                        struct pinctrl_dev *pctldev, int pin)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(pctldev, pin);
        struct st_gpio_bank *bank = gpio_range_to_bank(range);

        return &bank->pc;
}

/* Low level functions.. */
static inline int st_gpio_bank(int gpio)
{
        return gpio/ST_GPIO_PINS_PER_BANK;
}

static inline int st_gpio_pin(int gpio)
{
        return gpio%ST_GPIO_PINS_PER_BANK;
}

static void st_pinconf_set_config(struct st_pio_control *pc,
                                int pin, unsigned long config)
{
        struct regmap_field *output_enable = pc->oe;
        struct regmap_field *pull_up = pc->pu;
        struct regmap_field *open_drain = pc->od;
        unsigned int oe_value, pu_value, od_value;
        unsigned long mask = BIT(pin);

        if (output_enable) {
                regmap_field_read(output_enable, &oe_value);
                oe_value &= ~mask;
                if (config & ST_PINCONF_OE)
                        oe_value |= mask;
                regmap_field_write(output_enable, oe_value);
        }

        if (pull_up) {
                regmap_field_read(pull_up, &pu_value);
                pu_value &= ~mask;
                if (config & ST_PINCONF_PU)
                        pu_value |= mask;
                regmap_field_write(pull_up, pu_value);
        }

        if (open_drain) {
                regmap_field_read(open_drain, &od_value);
                od_value &= ~mask;
                if (config & ST_PINCONF_OD)
                        od_value |= mask;
                regmap_field_write(open_drain, od_value);
        }
}

static void st_pctl_set_function(struct st_pio_control *pc,
                                int pin_id, int function)
{
        struct regmap_field *alt = pc->alt;
        unsigned int val;
        int pin = st_gpio_pin(pin_id);
        int offset = pin * 4;

        if (!alt)
                return;

        regmap_field_read(alt, &val);
        val &= ~(0xf << offset);
        val |= function << offset;
        regmap_field_write(alt, val);
}

static unsigned int st_pctl_get_pin_function(struct st_pio_control *pc, int pin)
{
        struct regmap_field *alt = pc->alt;
        unsigned int val;
        int offset = pin * 4;

        if (!alt)
                return 0;

        regmap_field_read(alt, &val);

        return (val >> offset) & 0xf;
}

static unsigned long st_pinconf_delay_to_bit(unsigned int delay,
        const struct st_pctl_data *data, unsigned long config)
{
        const unsigned int *delay_times;
        int num_delay_times, i, closest_index = -1;
        unsigned int closest_divergence = UINT_MAX;

        if (ST_PINCONF_UNPACK_OE(config)) {
                delay_times = data->output_delays;
                num_delay_times = data->noutput_delays;
        } else {
                delay_times = data->input_delays;
                num_delay_times = data->ninput_delays;
        }

        for (i = 0; i < num_delay_times; i++) {
                unsigned int divergence = abs(delay - delay_times[i]);

                if (divergence == 0)
                        return i;

                if (divergence < closest_divergence) {
                        closest_divergence = divergence;
                        closest_index = i;
                }
        }

        pr_warn("Attempt to set delay %d, closest available %d\n",
             delay, delay_times[closest_index]);

        return closest_index;
}

static unsigned long st_pinconf_bit_to_delay(unsigned int index,
        const struct st_pctl_data *data, unsigned long output)
{
        const unsigned int *delay_times;
        int num_delay_times;

        if (output) {
                delay_times = data->output_delays;
                num_delay_times = data->noutput_delays;
        } else {
                delay_times = data->input_delays;
                num_delay_times = data->ninput_delays;
        }

        if (index < num_delay_times) {
                return delay_times[index];
        } else {
                pr_warn("Delay not found in/out delay list\n");
                return 0;
        }
}

static void st_regmap_field_bit_set_clear_pin(struct regmap_field *field,
        int enable, int pin)
{
        unsigned int val = 0;

        regmap_field_read(field, &val);
        if (enable)
                val |= BIT(pin);
        else
                val &= ~BIT(pin);
        regmap_field_write(field, val);
}

static void st_pinconf_set_retime_packed(struct st_pinctrl *info,
        struct st_pio_control *pc,      unsigned long config, int pin)
{
        const struct st_pctl_data *data = info->data;
        struct st_retime_packed *rt_p = &pc->rt.rt_p;
        unsigned int delay;

        st_regmap_field_bit_set_clear_pin(rt_p->clk1notclk0,
                                ST_PINCONF_UNPACK_RT_CLK(config), pin);

        st_regmap_field_bit_set_clear_pin(rt_p->clknotdata,
                                ST_PINCONF_UNPACK_RT_CLKNOTDATA(config), pin);

        st_regmap_field_bit_set_clear_pin(rt_p->double_edge,
                                ST_PINCONF_UNPACK_RT_DOUBLE_EDGE(config), pin);

        st_regmap_field_bit_set_clear_pin(rt_p->invertclk,
                                ST_PINCONF_UNPACK_RT_INVERTCLK(config), pin);

        st_regmap_field_bit_set_clear_pin(rt_p->retime,
                                ST_PINCONF_UNPACK_RT(config), pin);

        delay = st_pinconf_delay_to_bit(ST_PINCONF_UNPACK_RT_DELAY(config),
                                        data, config);
        /* 2 bit delay, lsb */
        st_regmap_field_bit_set_clear_pin(rt_p->delay_0, delay & 0x1, pin);
        /* 2 bit delay, msb */
        st_regmap_field_bit_set_clear_pin(rt_p->delay_1, delay & 0x2, pin);
}

static void st_pinconf_set_retime_dedicated(struct st_pinctrl *info,
        struct st_pio_control *pc, unsigned long config, int pin)
{
        int input       = ST_PINCONF_UNPACK_OE(config) ? 0 : 1;
        int clk         = ST_PINCONF_UNPACK_RT_CLK(config);
        int clknotdata  = ST_PINCONF_UNPACK_RT_CLKNOTDATA(config);
        int double_edge = ST_PINCONF_UNPACK_RT_DOUBLE_EDGE(config);
        int invertclk   = ST_PINCONF_UNPACK_RT_INVERTCLK(config);
        int retime      = ST_PINCONF_UNPACK_RT(config);

        unsigned long delay = st_pinconf_delay_to_bit(
                        ST_PINCONF_UNPACK_RT_DELAY(config),
                        info->data, config);
        struct st_retime_dedicated *rt_d = &pc->rt.rt_d;

        unsigned long retime_config =
                ((clk) << RT_D_CFG_CLK_SHIFT) |
                ((delay) << RT_D_CFG_DELAY_SHIFT) |
                ((input) << RT_D_CFG_DELAY_INNOTOUT_SHIFT) |
                ((retime) << RT_D_CFG_RETIME_SHIFT) |
                ((clknotdata) << RT_D_CFG_CLKNOTDATA_SHIFT) |
                ((invertclk) << RT_D_CFG_INVERTCLK_SHIFT) |
                ((double_edge) << RT_D_CFG_DOUBLE_EDGE_SHIFT);

        regmap_field_write(rt_d->rt[pin], retime_config);
}

static void st_pinconf_get_direction(struct st_pio_control *pc,
        int pin, unsigned long *config)
{
        unsigned int oe_value, pu_value, od_value;

        if (pc->oe) {
                regmap_field_read(pc->oe, &oe_value);
                if (oe_value & BIT(pin))
                        ST_PINCONF_PACK_OE(*config);
        }

        if (pc->pu) {
                regmap_field_read(pc->pu, &pu_value);
                if (pu_value & BIT(pin))
                        ST_PINCONF_PACK_PU(*config);
        }

        if (pc->od) {
                regmap_field_read(pc->od, &od_value);
                if (od_value & BIT(pin))
                        ST_PINCONF_PACK_OD(*config);
        }
}

static int st_pinconf_get_retime_packed(struct st_pinctrl *info,
        struct st_pio_control *pc,      int pin, unsigned long *config)
{
        const struct st_pctl_data *data = info->data;
        struct st_retime_packed *rt_p = &pc->rt.rt_p;
        unsigned int delay_bits, delay, delay0, delay1, val;
        int output = ST_PINCONF_UNPACK_OE(*config);

        if (!regmap_field_read(rt_p->retime, &val) && (val & BIT(pin)))
                ST_PINCONF_PACK_RT(*config);

        if (!regmap_field_read(rt_p->clk1notclk0, &val) && (val & BIT(pin)))
                ST_PINCONF_PACK_RT_CLK(*config, 1);

        if (!regmap_field_read(rt_p->clknotdata, &val) && (val & BIT(pin)))
                ST_PINCONF_PACK_RT_CLKNOTDATA(*config);

        if (!regmap_field_read(rt_p->double_edge, &val) && (val & BIT(pin)))
                ST_PINCONF_PACK_RT_DOUBLE_EDGE(*config);

        if (!regmap_field_read(rt_p->invertclk, &val) && (val & BIT(pin)))
                ST_PINCONF_PACK_RT_INVERTCLK(*config);

        regmap_field_read(rt_p->delay_0, &delay0);
        regmap_field_read(rt_p->delay_1, &delay1);
        delay_bits = (((delay1 & BIT(pin)) ? 1 : 0) << 1) |
                        (((delay0 & BIT(pin)) ? 1 : 0));
        delay =  st_pinconf_bit_to_delay(delay_bits, data, output);
        ST_PINCONF_PACK_RT_DELAY(*config, delay);

        return 0;
}

static int st_pinconf_get_retime_dedicated(struct st_pinctrl *info,
        struct st_pio_control *pc,      int pin, unsigned long *config)
{
        unsigned int value;
        unsigned long delay_bits, delay, rt_clk;
        int output = ST_PINCONF_UNPACK_OE(*config);
        struct st_retime_dedicated *rt_d = &pc->rt.rt_d;

        regmap_field_read(rt_d->rt[pin], &value);

        rt_clk = (value & RT_D_CFG_CLK_MASK) >> RT_D_CFG_CLK_SHIFT;
        ST_PINCONF_PACK_RT_CLK(*config, rt_clk);

        delay_bits = (value & RT_D_CFG_DELAY_MASK) >> RT_D_CFG_DELAY_SHIFT;
        delay =  st_pinconf_bit_to_delay(delay_bits, info->data, output);
        ST_PINCONF_PACK_RT_DELAY(*config, delay);

        if (value & RT_D_CFG_CLKNOTDATA_MASK)
                ST_PINCONF_PACK_RT_CLKNOTDATA(*config);

        if (value & RT_D_CFG_DOUBLE_EDGE_MASK)
                ST_PINCONF_PACK_RT_DOUBLE_EDGE(*config);

        if (value & RT_D_CFG_INVERTCLK_MASK)
                ST_PINCONF_PACK_RT_INVERTCLK(*config);

        if (value & RT_D_CFG_RETIME_MASK)
                ST_PINCONF_PACK_RT(*config);

        return 0;
}

/* GPIO related functions */

static inline void __st_gpio_set(struct st_gpio_bank *bank,
        unsigned offset, int value)
{
        if (value)
                writel(BIT(offset), bank->base + REG_PIO_SET_POUT);
        else
                writel(BIT(offset), bank->base + REG_PIO_CLR_POUT);
}

static void st_gpio_direction(struct st_gpio_bank *bank,
                unsigned int gpio, unsigned int direction)
{
        int offset = st_gpio_pin(gpio);
        int i = 0;
        /**
         * There are three configuration registers (PIOn_PC0, PIOn_PC1
         * and PIOn_PC2) for each port. These are used to configure the
         * PIO port pins. Each pin can be configured as an input, output,
         * bidirectional, or alternative function pin. Three bits, one bit
         * from each of the three registers, configure the corresponding bit of
         * the port. Valid bit settings is:
         *
         * PC2          PC1             PC0     Direction.
         * 0            0               0       [Input Weak pull-up]
         * 0            0 or 1          1       [Bidirection]
         * 0            1               0       [Output]
         * 1            0               0       [Input]
         *
         * PIOn_SET_PC and PIOn_CLR_PC registers are used to set and clear bits
         * individually.
         */
        for (i = 0; i <= 2; i++) {
                if (direction & BIT(i))
                        writel(BIT(offset), bank->base + REG_PIO_SET_PC(i));
                else
                        writel(BIT(offset), bank->base + REG_PIO_CLR_PC(i));
        }
}

static int st_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct st_gpio_bank *bank = gpiochip_get_data(chip);

        return !!(readl(bank->base + REG_PIO_PIN) & BIT(offset));
}

static void st_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
        struct st_gpio_bank *bank = gpiochip_get_data(chip);
        __st_gpio_set(bank, offset, value);
}

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

        return 0;
}

static int st_gpio_direction_output(struct gpio_chip *chip,
        unsigned offset, int value)
{
        struct st_gpio_bank *bank = gpiochip_get_data(chip);

        __st_gpio_set(bank, offset, value);
        pinctrl_gpio_direction_output(chip->base + offset);

        return 0;
}

static int st_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
        struct st_gpio_bank *bank = gpiochip_get_data(chip);
        struct st_pio_control pc = bank->pc;
        unsigned long config;
        unsigned int direction = 0;
        unsigned int function;
        unsigned int value;
        int i = 0;

        /* Alternate function direction is handled by Pinctrl */
        function = st_pctl_get_pin_function(&pc, offset);
        if (function) {
                st_pinconf_get_direction(&pc, offset, &config);
                if (ST_PINCONF_UNPACK_OE(config))
                        return GPIO_LINE_DIRECTION_OUT;

                return GPIO_LINE_DIRECTION_IN;
        }

        /*
         * GPIO direction is handled differently
         * - See st_gpio_direction() above for an explanation
         */
        for (i = 0; i <= 2; i++) {
                value = readl(bank->base + REG_PIO_PC(i));
                direction |= ((value >> offset) & 0x1) << i;
        }

        if (direction == ST_GPIO_DIRECTION_IN)
                return GPIO_LINE_DIRECTION_IN;

        return GPIO_LINE_DIRECTION_OUT;
}

/* Pinctrl Groups */
static int st_pctl_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->ngroups;
}

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

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

static int st_pctl_get_group_pins(struct pinctrl_dev *pctldev,
        unsigned selector, const unsigned **pins, unsigned *npins)
{
        struct st_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 inline const struct st_pctl_group *st_pctl_find_group_by_name(
        const struct st_pinctrl *info, const char *name)
{
        int i;

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

        return NULL;
}

static int st_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
        struct device_node *np, struct pinctrl_map **map, unsigned *num_maps)
{
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        const struct st_pctl_group *grp;
        struct pinctrl_map *new_map;
        struct device_node *parent;
        int map_num, i;

        grp = st_pctl_find_group_by_name(info, np->name);
        if (!grp) {
                dev_err(info->dev, "unable to find group for node %pOFn\n",
                        np);
                return -EINVAL;
        }

        map_num = grp->npins + 1;
        new_map = devm_kcalloc(pctldev->dev,
                                map_num, sizeof(*new_map), GFP_KERNEL);
        if (!new_map)
                return -ENOMEM;

        parent = of_get_parent(np);
        if (!parent) {
                devm_kfree(pctldev->dev, new_map);
                return -EINVAL;
        }

        *map = new_map;
        *num_maps = map_num;
        new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
        new_map[0].data.mux.function = parent->name;
        new_map[0].data.mux.group = np->name;
        of_node_put(parent);

        /* create config map per pin */
        new_map++;
        for (i = 0; i < grp->npins; i++) {
                new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;
                new_map[i].data.configs.group_or_pin =
                                pin_get_name(pctldev, grp->pins[i]);
                new_map[i].data.configs.configs = &grp->pin_conf[i].config;
                new_map[i].data.configs.num_configs = 1;
        }
        dev_info(pctldev->dev, "maps: function %s group %s num %d\n",
                (*map)->data.mux.function, grp->name, map_num);

        return 0;
}

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

static const struct pinctrl_ops st_pctlops = {
        .get_groups_count       = st_pctl_get_groups_count,
        .get_group_pins         = st_pctl_get_group_pins,
        .get_group_name         = st_pctl_get_group_name,
        .dt_node_to_map         = st_pctl_dt_node_to_map,
        .dt_free_map            = st_pctl_dt_free_map,
};

/* Pinmux */
static int st_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->nfunctions;
}

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

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

static int st_pmx_get_groups(struct pinctrl_dev *pctldev,
        unsigned selector, const char * const **grps, unsigned * const ngrps)
{
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        *grps = info->functions[selector].groups;
        *ngrps = info->functions[selector].ngroups;

        return 0;
}

static int st_pmx_set_mux(struct pinctrl_dev *pctldev, unsigned fselector,
                        unsigned group)
{
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        struct st_pinconf *conf = info->groups[group].pin_conf;
        struct st_pio_control *pc;
        int i;

        for (i = 0; i < info->groups[group].npins; i++) {
                pc = st_get_pio_control(pctldev, conf[i].pin);
                st_pctl_set_function(pc, conf[i].pin, conf[i].altfunc);
        }

        return 0;
}

static int st_pmx_set_gpio_direction(struct pinctrl_dev *pctldev,
                        struct pinctrl_gpio_range *range, unsigned gpio,
                        bool input)
{
        struct st_gpio_bank *bank = gpio_range_to_bank(range);
        /*
         * When a PIO bank is used in its primary function mode (altfunc = 0)
         * Output Enable (OE), Open Drain(OD), and Pull Up (PU)
         * for the primary PIO functions are driven by the related PIO block
         */
        st_pctl_set_function(&bank->pc, gpio, 0);
        st_gpio_direction(bank, gpio, input ?
                ST_GPIO_DIRECTION_IN : ST_GPIO_DIRECTION_OUT);

        return 0;
}

static const struct pinmux_ops st_pmxops = {
        .get_functions_count    = st_pmx_get_funcs_count,
        .get_function_name      = st_pmx_get_fname,
        .get_function_groups    = st_pmx_get_groups,
        .set_mux                = st_pmx_set_mux,
        .gpio_set_direction     = st_pmx_set_gpio_direction,
        .strict                 = true,
};

/* Pinconf  */
static void st_pinconf_get_retime(struct st_pinctrl *info,
        struct st_pio_control *pc, int pin, unsigned long *config)
{
        if (info->data->rt_style == st_retime_style_packed)
                st_pinconf_get_retime_packed(info, pc, pin, config);
        else if (info->data->rt_style == st_retime_style_dedicated)
                if ((BIT(pin) & pc->rt_pin_mask))
                        st_pinconf_get_retime_dedicated(info, pc,
                                        pin, config);
}

static void st_pinconf_set_retime(struct st_pinctrl *info,
        struct st_pio_control *pc, int pin, unsigned long config)
{
        if (info->data->rt_style == st_retime_style_packed)
                st_pinconf_set_retime_packed(info, pc, config, pin);
        else if (info->data->rt_style == st_retime_style_dedicated)
                if ((BIT(pin) & pc->rt_pin_mask))
                        st_pinconf_set_retime_dedicated(info, pc,
                                                        config, pin);
}

static int st_pinconf_set(struct pinctrl_dev *pctldev, unsigned pin_id,
                        unsigned long *configs, unsigned num_configs)
{
        int pin = st_gpio_pin(pin_id);
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        struct st_pio_control *pc = st_get_pio_control(pctldev, pin_id);
        int i;

        for (i = 0; i < num_configs; i++) {
                st_pinconf_set_config(pc, pin, configs[i]);
                st_pinconf_set_retime(info, pc, pin, configs[i]);
        } /* for each config */

        return 0;
}

static int st_pinconf_get(struct pinctrl_dev *pctldev,
                             unsigned pin_id, unsigned long *config)
{
        int pin = st_gpio_pin(pin_id);
        struct st_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        struct st_pio_control *pc = st_get_pio_control(pctldev, pin_id);

        *config = 0;
        st_pinconf_get_direction(pc, pin, config);
        st_pinconf_get_retime(info, pc, pin, config);

        return 0;
}

static void st_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                                   struct seq_file *s, unsigned pin_id)
{
        struct st_pio_control *pc;
        unsigned long config;

        unsigned int function;
        int offset = st_gpio_pin(pin_id);
        char f[16];
        int oe;

        mutex_unlock(&pctldev->mutex);
        pc = st_get_pio_control(pctldev, pin_id);
        st_pinconf_get(pctldev, pin_id, &config);
        mutex_lock(&pctldev->mutex);

        function = st_pctl_get_pin_function(pc, offset);
        if (function)
                snprintf(f, 10, "Alt Fn %u", function);
        else
                snprintf(f, 5, "GPIO");

        oe = st_gpio_get_direction(&pc_to_bank(pc)->gpio_chip, offset);
        seq_printf(s, "[OE:%d,PU:%ld,OD:%ld]\t%s\n"
                "\t\t[retime:%ld,invclk:%ld,clknotdat:%ld,"
                "de:%ld,rt-clk:%ld,rt-delay:%ld]",
                (oe == GPIO_LINE_DIRECTION_OUT),
                ST_PINCONF_UNPACK_PU(config),
                ST_PINCONF_UNPACK_OD(config),
                f,
                ST_PINCONF_UNPACK_RT(config),
                ST_PINCONF_UNPACK_RT_INVERTCLK(config),
                ST_PINCONF_UNPACK_RT_CLKNOTDATA(config),
                ST_PINCONF_UNPACK_RT_DOUBLE_EDGE(config),
                ST_PINCONF_UNPACK_RT_CLK(config),
                ST_PINCONF_UNPACK_RT_DELAY(config));
}

static const struct pinconf_ops st_confops = {
        .pin_config_get         = st_pinconf_get,
        .pin_config_set         = st_pinconf_set,
        .pin_config_dbg_show    = st_pinconf_dbg_show,
};

static void st_pctl_dt_child_count(struct st_pinctrl *info,
                                     struct device_node *np)
{
        struct device_node *child;
        for_each_child_of_node(np, child) {
                if (of_property_read_bool(child, "gpio-controller")) {
                        info->nbanks++;
                } else {
                        info->nfunctions++;
                        info->ngroups += of_get_child_count(child);
                }
        }
}

static int st_pctl_dt_setup_retime_packed(struct st_pinctrl *info,
        int bank, struct st_pio_control *pc)
{
        struct device *dev = info->dev;
        struct regmap *rm = info->regmap;
        const struct st_pctl_data *data = info->data;
        /* 2 registers per bank */
        int reg = (data->rt + bank * RT_P_CFGS_PER_BANK) * 4;
        struct st_retime_packed *rt_p = &pc->rt.rt_p;
        /* cfg0 */
        struct reg_field clk1notclk0 = RT_P_CFG0_CLK1NOTCLK0_FIELD(reg);
        struct reg_field delay_0 = RT_P_CFG0_DELAY_0_FIELD(reg);
        struct reg_field delay_1 = RT_P_CFG0_DELAY_1_FIELD(reg);
        /* cfg1 */
        struct reg_field invertclk = RT_P_CFG1_INVERTCLK_FIELD(reg + 4);
        struct reg_field retime = RT_P_CFG1_RETIME_FIELD(reg + 4);
        struct reg_field clknotdata = RT_P_CFG1_CLKNOTDATA_FIELD(reg + 4);
        struct reg_field double_edge = RT_P_CFG1_DOUBLE_EDGE_FIELD(reg + 4);

        rt_p->clk1notclk0 = devm_regmap_field_alloc(dev, rm, clk1notclk0);
        rt_p->delay_0   = devm_regmap_field_alloc(dev, rm, delay_0);
        rt_p->delay_1 = devm_regmap_field_alloc(dev, rm, delay_1);
        rt_p->invertclk = devm_regmap_field_alloc(dev, rm, invertclk);
        rt_p->retime = devm_regmap_field_alloc(dev, rm, retime);
        rt_p->clknotdata = devm_regmap_field_alloc(dev, rm, clknotdata);
        rt_p->double_edge = devm_regmap_field_alloc(dev, rm, double_edge);

        if (IS_ERR(rt_p->clk1notclk0) || IS_ERR(rt_p->delay_0) ||
                 IS_ERR(rt_p->delay_1) || IS_ERR(rt_p->invertclk) ||
                 IS_ERR(rt_p->retime) || IS_ERR(rt_p->clknotdata) ||
                 IS_ERR(rt_p->double_edge))
                return -EINVAL;

        return 0;
}

static int st_pctl_dt_setup_retime_dedicated(struct st_pinctrl *info,
        int bank, struct st_pio_control *pc)
{
        struct device *dev = info->dev;
        struct regmap *rm = info->regmap;
        const struct st_pctl_data *data = info->data;
        /* 8 registers per bank */
        int reg_offset = (data->rt + bank * RT_D_CFGS_PER_BANK) * 4;
        struct st_retime_dedicated *rt_d = &pc->rt.rt_d;
        unsigned int j;
        u32 pin_mask = pc->rt_pin_mask;

        for (j = 0; j < RT_D_CFGS_PER_BANK; j++) {
                if (BIT(j) & pin_mask) {
                        struct reg_field reg = REG_FIELD(reg_offset, 0, 31);
                        rt_d->rt[j] = devm_regmap_field_alloc(dev, rm, reg);
                        if (IS_ERR(rt_d->rt[j]))
                                return -EINVAL;
                        reg_offset += 4;
                }
        }
        return 0;
}

static int st_pctl_dt_setup_retime(struct st_pinctrl *info,
        int bank, struct st_pio_control *pc)
{
        const struct st_pctl_data *data = info->data;
        if (data->rt_style  == st_retime_style_packed)
                return st_pctl_dt_setup_retime_packed(info, bank, pc);
        else if (data->rt_style == st_retime_style_dedicated)
                return st_pctl_dt_setup_retime_dedicated(info, bank, pc);

        return -EINVAL;
}


static struct regmap_field *st_pc_get_value(struct device *dev,
                                            struct regmap *regmap, int bank,
                                            int data, int lsb, int msb)
{
        struct reg_field reg = REG_FIELD((data + bank) * 4, lsb, msb);

        if (data < 0)
                return NULL;

        return devm_regmap_field_alloc(dev, regmap, reg);
}

static void st_parse_syscfgs(struct st_pinctrl *info, int bank,
                             struct device_node *np)
{
        const struct st_pctl_data *data = info->data;
        /**
         * For a given shared register like OE/PU/OD, there are 8 bits per bank
         * 0:7 belongs to bank0, 8:15 belongs to bank1 ...
         * So each register is shared across 4 banks.
         */
        int lsb = (bank%4) * ST_GPIO_PINS_PER_BANK;
        int msb = lsb + ST_GPIO_PINS_PER_BANK - 1;
        struct st_pio_control *pc = &info->banks[bank].pc;
        struct device *dev = info->dev;
        struct regmap *regmap  = info->regmap;

        pc->alt = st_pc_get_value(dev, regmap, bank, data->alt, 0, 31);
        pc->oe = st_pc_get_value(dev, regmap, bank/4, data->oe, lsb, msb);
        pc->pu = st_pc_get_value(dev, regmap, bank/4, data->pu, lsb, msb);
        pc->od = st_pc_get_value(dev, regmap, bank/4, data->od, lsb, msb);

        /* retime avaiable for all pins by default */
        pc->rt_pin_mask = 0xff;
        of_property_read_u32(np, "st,retime-pin-mask", &pc->rt_pin_mask);
        st_pctl_dt_setup_retime(info, bank, pc);

        return;
}

/*
 * Each pin is represented in of the below forms.
 * <bank offset mux direction rt_type rt_delay rt_clk>
 */
static int st_pctl_dt_parse_groups(struct device_node *np,
        struct st_pctl_group *grp, struct st_pinctrl *info, int idx)
{
        /* bank pad direction val altfunction */
        const __be32 *list;
        struct property *pp;
        struct st_pinconf *conf;
        struct device_node *pins;
        int i = 0, npins = 0, nr_props, ret = 0;

        pins = of_get_child_by_name(np, "st,pins");
        if (!pins)
                return -ENODATA;

        for_each_property_of_node(pins, pp) {
                /* Skip those we do not want to proceed */
                if (!strcmp(pp->name, "name"))
                        continue;

                if (pp->length / sizeof(__be32) >= OF_GPIO_ARGS_MIN) {
                        npins++;
                } else {
                        pr_warn("Invalid st,pins in %pOFn node\n", np);
                        ret = -EINVAL;
                        goto out_put_node;
                }
        }

        grp->npins = npins;
        grp->name = np->name;
        grp->pins = devm_kcalloc(info->dev, npins, sizeof(u32), GFP_KERNEL);
        grp->pin_conf = devm_kcalloc(info->dev,
                                        npins, sizeof(*conf), GFP_KERNEL);

        if (!grp->pins || !grp->pin_conf) {
                ret = -ENOMEM;
                goto out_put_node;
        }

        /* <bank offset mux direction rt_type rt_delay rt_clk> */
        for_each_property_of_node(pins, pp) {
                if (!strcmp(pp->name, "name"))
                        continue;
                nr_props = pp->length/sizeof(u32);
                list = pp->value;
                conf = &grp->pin_conf[i];

                /* bank & offset */
                be32_to_cpup(list++);
                be32_to_cpup(list++);
                conf->pin = of_get_named_gpio(pins, pp->name, 0);
                conf->name = pp->name;
                grp->pins[i] = conf->pin;
                /* mux */
                conf->altfunc = be32_to_cpup(list++);
                conf->config = 0;
                /* direction */
                conf->config |= be32_to_cpup(list++);
                /* rt_type rt_delay rt_clk */
                if (nr_props >= OF_GPIO_ARGS_MIN + OF_RT_ARGS_MIN) {
                        /* rt_type */
                        conf->config |= be32_to_cpup(list++);
                        /* rt_delay */
                        conf->config |= be32_to_cpup(list++);
                        /* rt_clk */
                        if (nr_props > OF_GPIO_ARGS_MIN + OF_RT_ARGS_MIN)
                                conf->config |= be32_to_cpup(list++);
                }
                i++;
        }

out_put_node:
        of_node_put(pins);

        return ret;
}

static int st_pctl_parse_functions(struct device_node *np,
                        struct st_pinctrl *info, u32 index, int *grp_index)
{
        struct device_node *child;
        struct st_pmx_func *func;
        struct st_pctl_group *grp;
        int ret, i;

        func = &info->functions[index];
        func->name = np->name;
        func->ngroups = of_get_child_count(np);
        if (func->ngroups == 0) {
                dev_err(info->dev, "No groups defined\n");
                return -EINVAL;
        }
        func->groups = devm_kcalloc(info->dev,
                        func->ngroups, sizeof(char *), GFP_KERNEL);
        if (!func->groups)
                return -ENOMEM;

        i = 0;
        for_each_child_of_node(np, child) {
                func->groups[i] = child->name;
                grp = &info->groups[*grp_index];
                *grp_index += 1;
                ret = st_pctl_dt_parse_groups(child, grp, info, i++);
                if (ret) {
                        of_node_put(child);
                        return ret;
                }
        }
        dev_info(info->dev, "Function[%d\t name:%s,\tgroups:%d]\n",
                                index, func->name, func->ngroups);

        return 0;
}

static void st_gpio_irq_mask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct st_gpio_bank *bank = gpiochip_get_data(gc);

        writel(BIT(d->hwirq), bank->base + REG_PIO_CLR_PMASK);
}

static void st_gpio_irq_unmask(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct st_gpio_bank *bank = gpiochip_get_data(gc);

        writel(BIT(d->hwirq), bank->base + REG_PIO_SET_PMASK);
}

static int st_gpio_irq_request_resources(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

        st_gpio_direction_input(gc, d->hwirq);

        return gpiochip_lock_as_irq(gc, d->hwirq);
}

static void st_gpio_irq_release_resources(struct irq_data *d)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

        gpiochip_unlock_as_irq(gc, d->hwirq);
}

static int st_gpio_irq_set_type(struct irq_data *d, unsigned type)
{
        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
        struct st_gpio_bank *bank = gpiochip_get_data(gc);
        unsigned long flags;
        int comp, pin = d->hwirq;
        u32 val;
        u32 pin_edge_conf = 0;

        switch (type) {
        case IRQ_TYPE_LEVEL_HIGH:
                comp = 0;
                break;
        case IRQ_TYPE_EDGE_FALLING:
                comp = 0;
                pin_edge_conf = ST_IRQ_FALLING_EDGE_CONF(pin);
                break;
        case IRQ_TYPE_LEVEL_LOW:
                comp = 1;
                break;
        case IRQ_TYPE_EDGE_RISING:
                comp = 1;
                pin_edge_conf = ST_IRQ_RISING_EDGE_CONF(pin);
                break;
        case IRQ_TYPE_EDGE_BOTH:
                comp = st_gpio_get(&bank->gpio_chip, pin);
                pin_edge_conf = ST_IRQ_BOTH_EDGE_CONF(pin);
                break;
        default:
                return -EINVAL;
        }

        spin_lock_irqsave(&bank->lock, flags);
        bank->irq_edge_conf &=  ~(ST_IRQ_EDGE_MASK << (
                                pin * ST_IRQ_EDGE_CONF_BITS_PER_PIN));
        bank->irq_edge_conf |= pin_edge_conf;
        spin_unlock_irqrestore(&bank->lock, flags);

        val = readl(bank->base + REG_PIO_PCOMP);
        val &= ~BIT(pin);
        val |= (comp << pin);
        writel(val, bank->base + REG_PIO_PCOMP);

        return 0;
}

/*
 * As edge triggers are not supported at hardware level, it is supported by
 * software by exploiting the level trigger support in hardware.
 *
 * Steps for detection raising edge interrupt in software.
 *
 * Step 1: CONFIGURE pin to detect level LOW interrupts.
 *
 * Step 2: DETECT level LOW interrupt and in irqmux/gpio bank interrupt handler,
 * if the value of pin is low, then CONFIGURE pin for level HIGH interrupt.
 * IGNORE calling the actual interrupt handler for the pin at this stage.
 *
 * Step 3: DETECT level HIGH interrupt and in irqmux/gpio-bank interrupt handler
 * if the value of pin is HIGH, CONFIGURE pin for level LOW interrupt and then
 * DISPATCH the interrupt to the interrupt handler of the pin.
 *
 *               step-1  ________     __________
 *                              |     | step - 3
 *                              |     |
 *                      step -2 |_____|
 *
 * falling edge is also detected int the same way.
 *
 */
static void __gpio_irq_handler(struct st_gpio_bank *bank)
{
        unsigned long port_in, port_mask, port_comp, active_irqs;
        unsigned long bank_edge_mask, flags;
        int n, val, ecfg;

        spin_lock_irqsave(&bank->lock, flags);
        bank_edge_mask = bank->irq_edge_conf;
        spin_unlock_irqrestore(&bank->lock, flags);

        for (;;) {
                port_in = readl(bank->base + REG_PIO_PIN);
                port_comp = readl(bank->base + REG_PIO_PCOMP);
                port_mask = readl(bank->base + REG_PIO_PMASK);

                active_irqs = (port_in ^ port_comp) & port_mask;

                if (active_irqs == 0)
                        break;

                for_each_set_bit(n, &active_irqs, BITS_PER_LONG) {
                        /* check if we are detecting fake edges ... */
                        ecfg = ST_IRQ_EDGE_CONF(bank_edge_mask, n);

                        if (ecfg) {
                                /* edge detection. */
                                val = st_gpio_get(&bank->gpio_chip, n);

                                writel(BIT(n),
                                        val ? bank->base + REG_PIO_SET_PCOMP :
                                        bank->base + REG_PIO_CLR_PCOMP);

                                if (ecfg != ST_IRQ_EDGE_BOTH &&
                                        !((ecfg & ST_IRQ_EDGE_FALLING) ^ val))
                                        continue;
                        }

                        generic_handle_domain_irq(bank->gpio_chip.irq.domain, n);
                }
        }
}

static void st_gpio_irq_handler(struct irq_desc *desc)
{
        /* interrupt dedicated per bank */
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct gpio_chip *gc = irq_desc_get_handler_data(desc);
        struct st_gpio_bank *bank = gpiochip_get_data(gc);

        chained_irq_enter(chip, desc);
        __gpio_irq_handler(bank);
        chained_irq_exit(chip, desc);
}

static void st_gpio_irqmux_handler(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct st_pinctrl *info = irq_desc_get_handler_data(desc);
        unsigned long status;
        int n;

        chained_irq_enter(chip, desc);

        status = readl(info->irqmux_base);

        for_each_set_bit(n, &status, info->nbanks)
                __gpio_irq_handler(&info->banks[n]);

        chained_irq_exit(chip, desc);
}

static const struct gpio_chip st_gpio_template = {
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .get                    = st_gpio_get,
        .set                    = st_gpio_set,
        .direction_input        = st_gpio_direction_input,
        .direction_output       = st_gpio_direction_output,
        .get_direction          = st_gpio_get_direction,
        .ngpio                  = ST_GPIO_PINS_PER_BANK,
};

static struct irq_chip st_gpio_irqchip = {
        .name                   = "GPIO",
        .irq_request_resources  = st_gpio_irq_request_resources,
        .irq_release_resources  = st_gpio_irq_release_resources,
        .irq_disable            = st_gpio_irq_mask,
        .irq_mask               = st_gpio_irq_mask,
        .irq_unmask             = st_gpio_irq_unmask,
        .irq_set_type           = st_gpio_irq_set_type,
        .flags                  = IRQCHIP_SKIP_SET_WAKE,
};

static int st_gpiolib_register_bank(struct st_pinctrl *info,
        int bank_nr, struct device_node *np)
{
        struct st_gpio_bank *bank = &info->banks[bank_nr];
        struct pinctrl_gpio_range *range = &bank->range;
        struct device *dev = info->dev;
        int bank_num = of_alias_get_id(np, "gpio");
        struct resource res, irq_res;
        int err;

        if (of_address_to_resource(np, 0, &res))
                return -ENODEV;

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

        bank->gpio_chip = st_gpio_template;
        bank->gpio_chip.base = bank_num * ST_GPIO_PINS_PER_BANK;
        bank->gpio_chip.ngpio = ST_GPIO_PINS_PER_BANK;
        bank->gpio_chip.of_node = np;
        bank->gpio_chip.parent = dev;
        spin_lock_init(&bank->lock);

        of_property_read_string(np, "st,bank-name", &range->name);
        bank->gpio_chip.label = range->name;

        range->id = bank_num;
        range->pin_base = range->base = range->id * ST_GPIO_PINS_PER_BANK;
        range->npins = bank->gpio_chip.ngpio;
        range->gc = &bank->gpio_chip;

        /**
         * GPIO bank can have one of the two possible types of
         * interrupt-wirings.
         *
         * First type is via irqmux, single interrupt is used by multiple
         * gpio banks. This reduces number of overall interrupts numbers
         * required. All these banks belong to a single pincontroller.
         *                _________
         *               |         |----> [gpio-bank (n)    ]
         *               |         |----> [gpio-bank (n + 1)]
         *      [irqN]-- | irq-mux |----> [gpio-bank (n + 2)]
         *               |         |----> [gpio-bank (...  )]
         *               |_________|----> [gpio-bank (n + 7)]
         *
         * Second type has a dedicated interrupt per each gpio bank.
         *
         *      [irqN]----> [gpio-bank (n)]
         */

        if (of_irq_to_resource(np, 0, &irq_res) > 0) {
                struct gpio_irq_chip *girq;
                int gpio_irq = irq_res.start;

                /* This is not a valid IRQ */
                if (gpio_irq <= 0) {
                        dev_err(dev, "invalid IRQ for %pOF bank\n", np);
                        goto skip_irq;
                }
                /* We need to have a mux as well */
                if (!info->irqmux_base) {
                        dev_err(dev, "no irqmux for %pOF bank\n", np);
                        goto skip_irq;
                }

                girq = &bank->gpio_chip.irq;
                girq->chip = &st_gpio_irqchip;
                girq->parent_handler = st_gpio_irq_handler;
                girq->num_parents = 1;
                girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
                                             GFP_KERNEL);
                if (!girq->parents)
                        return -ENOMEM;
                girq->parents[0] = gpio_irq;
                girq->default_type = IRQ_TYPE_NONE;
                girq->handler = handle_simple_irq;
        }

skip_irq:
        err  = gpiochip_add_data(&bank->gpio_chip, bank);
        if (err) {
                dev_err(dev, "Failed to add gpiochip(%d)!\n", bank_num);
                return err;
        }
        dev_info(dev, "%s bank added.\n", range->name);

        return 0;
}

static const struct of_device_id st_pctl_of_match[] = {
        { .compatible = "st,stih407-sbc-pinctrl", .data = &stih407_data},
        { .compatible = "st,stih407-front-pinctrl", .data = &stih407_data},
        { .compatible = "st,stih407-rear-pinctrl", .data = &stih407_data},
        { .compatible = "st,stih407-flash-pinctrl", .data = &stih407_flashdata},
        { /* sentinel */ }
};

static int st_pctl_probe_dt(struct platform_device *pdev,
        struct pinctrl_desc *pctl_desc, struct st_pinctrl *info)
{
        int ret = 0;
        int i = 0, j = 0, k = 0, bank;
        struct pinctrl_pin_desc *pdesc;
        struct device_node *np = pdev->dev.of_node;
        struct device_node *child;
        int grp_index = 0;
        int irq = 0;
        struct resource *res;

        st_pctl_dt_child_count(info, np);
        if (!info->nbanks) {
                dev_err(&pdev->dev, "you need atleast one gpio bank\n");
                return -EINVAL;
        }

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

        info->functions = devm_kcalloc(&pdev->dev,
                info->nfunctions, sizeof(*info->functions), GFP_KERNEL);

        info->groups = devm_kcalloc(&pdev->dev,
                        info->ngroups, sizeof(*info->groups),
                        GFP_KERNEL);

        info->banks = devm_kcalloc(&pdev->dev,
                        info->nbanks, sizeof(*info->banks), GFP_KERNEL);

        if (!info->functions || !info->groups || !info->banks)
                return -ENOMEM;

        info->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
        if (IS_ERR(info->regmap)) {
                dev_err(info->dev, "No syscfg phandle specified\n");
                return PTR_ERR(info->regmap);
        }
        info->data = of_match_node(st_pctl_of_match, np)->data;

        irq = platform_get_irq(pdev, 0);

        if (irq > 0) {
                res = platform_get_resource_byname(pdev,
                                        IORESOURCE_MEM, "irqmux");
                info->irqmux_base = devm_ioremap_resource(&pdev->dev, res);

                if (IS_ERR(info->irqmux_base))
                        return PTR_ERR(info->irqmux_base);

                irq_set_chained_handler_and_data(irq, st_gpio_irqmux_handler,
                                                 info);

        }

        pctl_desc->npins = info->nbanks * ST_GPIO_PINS_PER_BANK;
        pdesc = devm_kcalloc(&pdev->dev,
                        pctl_desc->npins, sizeof(*pdesc), GFP_KERNEL);
        if (!pdesc)
                return -ENOMEM;

        pctl_desc->pins = pdesc;

        bank = 0;
        for_each_child_of_node(np, child) {
                if (of_property_read_bool(child, "gpio-controller")) {
                        const char *bank_name = NULL;
                        ret = st_gpiolib_register_bank(info, bank, child);
                        if (ret) {
                                of_node_put(child);
                                return ret;
                        }

                        k = info->banks[bank].range.pin_base;
                        bank_name = info->banks[bank].range.name;
                        for (j = 0; j < ST_GPIO_PINS_PER_BANK; j++, k++) {
                                pdesc->number = k;
                                pdesc->name = kasprintf(GFP_KERNEL, "%s[%d]",
                                                        bank_name, j);
                                pdesc++;
                        }
                        st_parse_syscfgs(info, bank, child);
                        bank++;
                } else {
                        ret = st_pctl_parse_functions(child, info,
                                                        i++, &grp_index);
                        if (ret) {
                                dev_err(&pdev->dev, "No functions found.\n");
                                of_node_put(child);
                                return ret;
                        }
                }
        }

        return 0;
}

static int st_pctl_probe(struct platform_device *pdev)
{
        struct st_pinctrl *info;
        struct pinctrl_desc *pctl_desc;
        int ret, i;

        if (!pdev->dev.of_node) {
                dev_err(&pdev->dev, "device node not found.\n");
                return -EINVAL;
        }

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

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

        info->dev = &pdev->dev;
        platform_set_drvdata(pdev, info);
        ret = st_pctl_probe_dt(pdev, pctl_desc, info);
        if (ret)
                return ret;

        pctl_desc->owner        = THIS_MODULE;
        pctl_desc->pctlops      = &st_pctlops;
        pctl_desc->pmxops       = &st_pmxops;
        pctl_desc->confops      = &st_confops;
        pctl_desc->name         = dev_name(&pdev->dev);

        info->pctl = devm_pinctrl_register(&pdev->dev, pctl_desc, info);
        if (IS_ERR(info->pctl)) {
                dev_err(&pdev->dev, "Failed pinctrl registration\n");
                return PTR_ERR(info->pctl);
        }

        for (i = 0; i < info->nbanks; i++)
                pinctrl_add_gpio_range(info->pctl, &info->banks[i].range);

        return 0;
}

static struct platform_driver st_pctl_driver = {
        .driver = {
                .name = "st-pinctrl",
                .of_match_table = st_pctl_of_match,
        },
        .probe = st_pctl_probe,
};

static int __init st_pctl_init(void)
{
        return platform_driver_register(&st_pctl_driver);
}
arch_initcall(st_pctl_init);