linux-imx

/*

 * AR71xx Reset Controller Driver

 * Author: Alban Bedel

 *

 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>

 *

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

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

​

#include <linux/io.h>

#include <linux/init.h>

#include <linux/mod_devicetable.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>

#include <linux/reboot.h>

​

struct ath79_reset {

    struct reset_controller_dev rcdev;

    struct notifier_block restart_nb;

    void __iomem *base;

    spinlock_t lock;

};

​

#define FULL_CHIP_RESET 24

​

static int ath79_reset_update(struct reset_controller_dev *rcdev,

            unsigned long id, bool assert)

{

    struct ath79_reset *ath79_reset =

        container_of(rcdev, struct ath79_reset, rcdev);

    unsigned long flags;

    u32 val;

​

    spin_lock_irqsave(&ath79_reset->lock, flags);

    val = readl(ath79_reset->base);

    if (assert)

        val |= BIT(id);

    else

        val &= ~BIT(id);

    writel(val, ath79_reset->base);

    spin_unlock_irqrestore(&ath79_reset->lock, flags);

​

    return 0;

}

​

static int ath79_reset_assert(struct reset_controller_dev *rcdev,

            unsigned long id)

{

    return ath79_reset_update(rcdev, id, true);

}

​

static int ath79_reset_deassert(struct reset_controller_dev *rcdev,

                unsigned long id)

{

    return ath79_reset_update(rcdev, id, false);

}

​

static int ath79_reset_status(struct reset_controller_dev *rcdev,

            unsigned long id)

{

    struct ath79_reset *ath79_reset =

        container_of(rcdev, struct ath79_reset, rcdev);

    u32 val;

​

    val = readl(ath79_reset->base);

​

    return !!(val & BIT(id));

}

​

static const struct reset_control_ops ath79_reset_ops = {

    .assert = ath79_reset_assert,

    .deassert = ath79_reset_deassert,

    .status = ath79_reset_status,

};

​

static int ath79_reset_restart_handler(struct notifier_block *nb,

                unsigned long action, void *data)

{

    struct ath79_reset *ath79_reset =

        container_of(nb, struct ath79_reset, restart_nb);

​

    ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);

​

    return NOTIFY_DONE;