linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO

 *

 * Copyright (C) 2009 VIA Technologies, Inc.

 * Copyright (C) 2010 One Laptop per Child

 * Author: Harald Welte <HaraldWelte@viatech.com>

 * All rights reserved.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/gpio/driver.h>

#include <linux/slab.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/pci.h>

#include <linux/io.h>

​

#define MODULE_NAME "vx855_gpio"

​

/* The VX855 south bridge has the following GPIO pins:

 *  GPI 0...13  General Purpose Input

 *  GPO 0...12  General Purpose Output

 *  GPIO 0...14 General Purpose I/O (Open-Drain)

 */

​

#define NR_VX855_GPI    14

#define NR_VX855_GPO    13

#define NR_VX855_GPIO   15

​

#define NR_VX855_GPInO  (NR_VX855_GPI + NR_VX855_GPO)

#define NR_VX855_GP (NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)

​

struct vx855_gpio {

    struct gpio_chip gpio;

    spinlock_t lock;

    u32 io_gpi;

    u32 io_gpo;

};

​

/* resolve a GPIx into the corresponding bit position */

static inline u_int32_t gpi_i_bit(int i)

{

    if (i < 10)

        return 1 << i;

    else

        return 1 << (i + 14);

}

​

static inline u_int32_t gpo_o_bit(int i)

{

    if (i < 11)

        return 1 << i;

    else

        return 1 << (i + 14);

}

​

static inline u_int32_t gpio_i_bit(int i)

{

    if (i < 14)

        return 1 << (i + 10);

    else

        return 1 << (i + 14);

}

​

static inline u_int32_t gpio_o_bit(int i)

{

    if (i < 14)

        return 1 << (i + 11);

    else

        return 1 << (i + 13);

}

​

/* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering:

 * 0..13    GPI 0..13

 * 14..26   GPO 0..12

 * 27..41   GPIO 0..14

 */

​

static int vx855gpio_direction_input(struct gpio_chip *gpio,

                     unsigned int nr)

{

    struct vx855_gpio *vg = gpiochip_get_data(gpio);

    unsigned long flags;

    u_int32_t reg_out;

​

    /* Real GPI bits are always in input direction */

    if (nr < NR_VX855_GPI)

        return 0;

​

    /* Real GPO bits cannot be put in output direction */

    if (nr < NR_VX855_GPInO)