linux-imx

/*

 * Copyright (C) 2015 ST Microelectronics

 *

 * Author: Lee Jones <lee.jones@linaro.org>

 *

 * 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.

 */

​

#include <linux/debugfs.h>

#include <linux/err.h>

#include <linux/fs.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/mailbox_client.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/poll.h>

#include <linux/slab.h>

#include <linux/uaccess.h>

#include <linux/sched/signal.h>

​

#define MBOX_MAX_SIG_LEN    8

#define MBOX_MAX_MSG_LEN    128

#define MBOX_BYTES_PER_LINE 16

#define MBOX_HEXDUMP_LINE_LEN   ((MBOX_BYTES_PER_LINE * 4) + 2)

#define MBOX_HEXDUMP_MAX_LEN    (MBOX_HEXDUMP_LINE_LEN *        \

                 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))

​

static bool mbox_data_ready;

​

struct mbox_test_device {

    struct device       *dev;

    void __iomem        *tx_mmio;

    void __iomem        *rx_mmio;

    struct mbox_chan    *tx_channel;

    struct mbox_chan    *rx_channel;

    char            *rx_buffer;

    char            *signal;

    char            *message;

    spinlock_t      lock;

    wait_queue_head_t   waitq;

    struct fasync_struct    *async_queue;

    struct dentry       *root_debugfs_dir;

};

​

static ssize_t mbox_test_signal_write(struct file *filp,

                       const char __user *userbuf,

                       size_t count, loff_t *ppos)

{

    struct mbox_test_device *tdev = filp->private_data;

​

    if (!tdev->tx_channel) {

        dev_err(tdev->dev, "Channel cannot do Tx\n");

        return -EINVAL;

    }

​

    if (count > MBOX_MAX_SIG_LEN) {

        dev_err(tdev->dev,

            "Signal length %zd greater than max allowed %d\n",

            count, MBOX_MAX_SIG_LEN);

        return -EINVAL;

    }

​

    /* Only allocate memory if we need to */

    if (!tdev->signal) {

        tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);

        if (!tdev->signal)

            return -ENOMEM;

    }

​

    if (copy_from_user(tdev->signal, userbuf, count)) {

        kfree(tdev->signal);

        tdev->signal = NULL;

        return -EFAULT;

    }

​

    return count;

}

​

static const struct file_operations mbox_test_signal_ops = {

    .write  = mbox_test_signal_write,

    .open   = simple_open,

    .llseek = generic_file_llseek,

};

​

static int mbox_test_message_fasync(int fd, struct file *filp, int on)

{

    struct mbox_test_device *tdev = filp->private_data;