linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * GPIO interface for Intel Poulsbo SCH

 *

 *  Copyright (c) 2010 CompuLab Ltd

 *  Author: Denis Turischev <denis@compulab.co.il>

 */

​

#include <linux/acpi.h>

#include <linux/errno.h>

#include <linux/gpio/driver.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/pci_ids.h>

#include <linux/platform_device.h>

​

#define GEN 0x00

#define GIO 0x04

#define GLV 0x08

​

struct sch_gpio {

    struct gpio_chip chip;

    spinlock_t lock;

    unsigned short iobase;

    unsigned short resume_base;

};

​

static unsigned sch_gpio_offset(struct sch_gpio *sch, unsigned gpio,

                unsigned reg)

{

    unsigned base = 0;

​

    if (gpio >= sch->resume_base) {

        gpio -= sch->resume_base;

        base += 0x20;

    }

​

    return base + reg + gpio / 8;

}

​

static unsigned sch_gpio_bit(struct sch_gpio *sch, unsigned gpio)

{

    if (gpio >= sch->resume_base)

        gpio -= sch->resume_base;

    return gpio % 8;

}

​

static int sch_gpio_reg_get(struct sch_gpio *sch, unsigned gpio, unsigned reg)

{

    unsigned short offset, bit;

    u8 reg_val;

​

    offset = sch_gpio_offset(sch, gpio, reg);

    bit = sch_gpio_bit(sch, gpio);

​

    reg_val = !!(inb(sch->iobase + offset) & BIT(bit));

​

    return reg_val;

}

​

static void sch_gpio_reg_set(struct sch_gpio *sch, unsigned gpio, unsigned reg,

                 int val)

{

    unsigned short offset, bit;

    u8 reg_val;

​

    offset = sch_gpio_offset(sch, gpio, reg);

    bit = sch_gpio_bit(sch, gpio);

​

    reg_val = inb(sch->iobase + offset);

​

    if (val)

        outb(reg_val | BIT(bit), sch->iobase + offset);

    else

        outb((reg_val & ~BIT(bit)), sch->iobase + offset);

}

​

static int sch_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)

{

    struct sch_gpio *sch = gpiochip_get_data(gc);

​

    spin_lock(&sch->lock);

    sch_gpio_reg_set(sch, gpio_num, GIO, 1);

    spin_unlock(&sch->lock);

    return 0;

}

​

static int sch_gpio_get(struct gpio_chip *gc, unsigned gpio_num)

{

    struct sch_gpio *sch = gpiochip_get_data(gc);

    return sch_gpio_reg_get(sch, gpio_num, GLV);