linux-imx

/*

 * AMD Promontory GPIO driver

 *

 * Copyright (C) 2015 ASMedia Technology Inc.

 * Author: YD Tseng <yd_tseng@asmedia.com.tw>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/gpio/driver.h>

#include <linux/spinlock.h>

#include <linux/acpi.h>

#include <linux/platform_device.h>

​

#define PT_TOTAL_GPIO 8

​

/* PCI-E MMIO register offsets */

#define PT_DIRECTION_REG   0x00

#define PT_INPUTDATA_REG   0x04

#define PT_OUTPUTDATA_REG  0x08

#define PT_CLOCKRATE_REG   0x0C

#define PT_SYNC_REG        0x28

​

struct pt_gpio_chip {

    struct gpio_chip         gc;

    void __iomem             *reg_base;

};

​

static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)

{

    struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);

    unsigned long flags;

    u32 using_pins;

​

    dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);

​

    spin_lock_irqsave(&gc->bgpio_lock, flags);

​

    using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);

    if (using_pins & BIT(offset)) {

        dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",

             offset);

        spin_unlock_irqrestore(&gc->bgpio_lock, flags);

        return -EINVAL;

    }

​

    writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);

​

    spin_unlock_irqrestore(&gc->bgpio_lock, flags);

​

    return 0;

}

​

static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)

{

    struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);

    unsigned long flags;

    u32 using_pins;

​