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bf562bc5a8
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
452 lines
11 KiB
C
452 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2015 ST Microelectronics
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*
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* Author: Lee Jones <lee.jones@linaro.org>
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*/
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#include <linux/debugfs.h>
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#include <linux/err.h>
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#include <linux/fs.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/mailbox_client.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/sched/signal.h>
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#define MBOX_MAX_SIG_LEN 8
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#define MBOX_MAX_MSG_LEN 128
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#define MBOX_BYTES_PER_LINE 16
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#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
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#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
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(MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
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static bool mbox_data_ready;
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struct mbox_test_device {
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struct device *dev;
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void __iomem *tx_mmio;
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void __iomem *rx_mmio;
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struct mbox_chan *tx_channel;
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struct mbox_chan *rx_channel;
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char *rx_buffer;
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char *signal;
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char *message;
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spinlock_t lock;
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struct mutex mutex;
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wait_queue_head_t waitq;
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struct fasync_struct *async_queue;
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struct dentry *root_debugfs_dir;
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};
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static ssize_t mbox_test_signal_write(struct file *filp,
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const char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct mbox_test_device *tdev = filp->private_data;
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if (!tdev->tx_channel) {
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dev_err(tdev->dev, "Channel cannot do Tx\n");
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return -EINVAL;
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}
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if (count > MBOX_MAX_SIG_LEN) {
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dev_err(tdev->dev,
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"Signal length %zd greater than max allowed %d\n",
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count, MBOX_MAX_SIG_LEN);
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return -EINVAL;
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}
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/* Only allocate memory if we need to */
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if (!tdev->signal) {
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tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
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if (!tdev->signal)
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return -ENOMEM;
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}
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if (copy_from_user(tdev->signal, userbuf, count)) {
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kfree(tdev->signal);
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tdev->signal = NULL;
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return -EFAULT;
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}
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return count;
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}
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static const struct file_operations mbox_test_signal_ops = {
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.write = mbox_test_signal_write,
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.open = simple_open,
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.llseek = generic_file_llseek,
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};
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static int mbox_test_message_fasync(int fd, struct file *filp, int on)
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{
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struct mbox_test_device *tdev = filp->private_data;
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return fasync_helper(fd, filp, on, &tdev->async_queue);
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}
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static ssize_t mbox_test_message_write(struct file *filp,
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const char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct mbox_test_device *tdev = filp->private_data;
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char *message;
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void *data;
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int ret;
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if (!tdev->tx_channel) {
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dev_err(tdev->dev, "Channel cannot do Tx\n");
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return -EINVAL;
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}
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if (count > MBOX_MAX_MSG_LEN) {
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dev_err(tdev->dev,
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"Message length %zd greater than max allowed %d\n",
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count, MBOX_MAX_MSG_LEN);
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return -EINVAL;
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}
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message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
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if (!message)
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return -ENOMEM;
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mutex_lock(&tdev->mutex);
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tdev->message = message;
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ret = copy_from_user(tdev->message, userbuf, count);
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if (ret) {
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ret = -EFAULT;
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goto out;
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}
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/*
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* A separate signal is only of use if there is
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* MMIO to subsequently pass the message through
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*/
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if (tdev->tx_mmio && tdev->signal) {
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print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
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tdev->signal, MBOX_MAX_SIG_LEN);
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data = tdev->signal;
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} else
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data = tdev->message;
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print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
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tdev->message, MBOX_MAX_MSG_LEN);
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ret = mbox_send_message(tdev->tx_channel, data);
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if (ret < 0)
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dev_err(tdev->dev, "Failed to send message via mailbox\n");
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out:
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kfree(tdev->signal);
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kfree(tdev->message);
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tdev->signal = NULL;
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mutex_unlock(&tdev->mutex);
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return ret < 0 ? ret : count;
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}
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static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
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{
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bool data_ready;
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unsigned long flags;
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spin_lock_irqsave(&tdev->lock, flags);
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data_ready = mbox_data_ready;
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spin_unlock_irqrestore(&tdev->lock, flags);
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return data_ready;
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}
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static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct mbox_test_device *tdev = filp->private_data;
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unsigned long flags;
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char *touser, *ptr;
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int l = 0;
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int ret;
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DECLARE_WAITQUEUE(wait, current);
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touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
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if (!touser)
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return -ENOMEM;
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if (!tdev->rx_channel) {
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ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
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ret = simple_read_from_buffer(userbuf, count, ppos,
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touser, ret);
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goto kfree_err;
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}
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add_wait_queue(&tdev->waitq, &wait);
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do {
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__set_current_state(TASK_INTERRUPTIBLE);
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if (mbox_test_message_data_ready(tdev))
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break;
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if (filp->f_flags & O_NONBLOCK) {
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ret = -EAGAIN;
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goto waitq_err;
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}
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if (signal_pending(current)) {
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ret = -ERESTARTSYS;
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goto waitq_err;
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}
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schedule();
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} while (1);
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spin_lock_irqsave(&tdev->lock, flags);
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ptr = tdev->rx_buffer;
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while (l < MBOX_HEXDUMP_MAX_LEN) {
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hex_dump_to_buffer(ptr,
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MBOX_BYTES_PER_LINE,
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MBOX_BYTES_PER_LINE, 1, touser + l,
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MBOX_HEXDUMP_LINE_LEN, true);
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ptr += MBOX_BYTES_PER_LINE;
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l += MBOX_HEXDUMP_LINE_LEN;
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*(touser + (l - 1)) = '\n';
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}
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*(touser + l) = '\0';
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memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
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mbox_data_ready = false;
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spin_unlock_irqrestore(&tdev->lock, flags);
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ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
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waitq_err:
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&tdev->waitq, &wait);
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kfree_err:
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kfree(touser);
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return ret;
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}
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static __poll_t
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mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
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{
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struct mbox_test_device *tdev = filp->private_data;
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poll_wait(filp, &tdev->waitq, wait);
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if (mbox_test_message_data_ready(tdev))
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return EPOLLIN | EPOLLRDNORM;
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return 0;
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}
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static const struct file_operations mbox_test_message_ops = {
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.write = mbox_test_message_write,
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.read = mbox_test_message_read,
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.fasync = mbox_test_message_fasync,
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.poll = mbox_test_message_poll,
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.open = simple_open,
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.llseek = generic_file_llseek,
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};
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static int mbox_test_add_debugfs(struct platform_device *pdev,
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struct mbox_test_device *tdev)
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{
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if (!debugfs_initialized())
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return 0;
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tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL);
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if (!tdev->root_debugfs_dir) {
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dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
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return -EINVAL;
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}
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debugfs_create_file("message", 0600, tdev->root_debugfs_dir,
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tdev, &mbox_test_message_ops);
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debugfs_create_file("signal", 0200, tdev->root_debugfs_dir,
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tdev, &mbox_test_signal_ops);
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return 0;
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}
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static void mbox_test_receive_message(struct mbox_client *client, void *message)
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{
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struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
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unsigned long flags;
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spin_lock_irqsave(&tdev->lock, flags);
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if (tdev->rx_mmio) {
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memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
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print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
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tdev->rx_buffer, MBOX_MAX_MSG_LEN);
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} else if (message) {
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print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
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message, MBOX_MAX_MSG_LEN);
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memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
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}
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mbox_data_ready = true;
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spin_unlock_irqrestore(&tdev->lock, flags);
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wake_up_interruptible(&tdev->waitq);
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kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
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}
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static void mbox_test_prepare_message(struct mbox_client *client, void *message)
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{
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struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
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if (tdev->tx_mmio) {
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if (tdev->signal)
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memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
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else
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memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
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}
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}
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static void mbox_test_message_sent(struct mbox_client *client,
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void *message, int r)
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{
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if (r)
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dev_warn(client->dev,
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"Client: Message could not be sent: %d\n", r);
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else
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dev_info(client->dev,
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"Client: Message sent\n");
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}
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static struct mbox_chan *
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mbox_test_request_channel(struct platform_device *pdev, const char *name)
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{
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struct mbox_client *client;
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struct mbox_chan *channel;
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client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
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if (!client)
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return ERR_PTR(-ENOMEM);
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client->dev = &pdev->dev;
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client->rx_callback = mbox_test_receive_message;
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client->tx_prepare = mbox_test_prepare_message;
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client->tx_done = mbox_test_message_sent;
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client->tx_block = true;
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client->knows_txdone = false;
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client->tx_tout = 500;
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channel = mbox_request_channel_byname(client, name);
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if (IS_ERR(channel)) {
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dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
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return NULL;
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}
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return channel;
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}
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static int mbox_test_probe(struct platform_device *pdev)
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{
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struct mbox_test_device *tdev;
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struct resource *res;
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resource_size_t size;
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int ret;
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tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
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if (!tdev)
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return -ENOMEM;
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/* It's okay for MMIO to be NULL */
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tdev->tx_mmio = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
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if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
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/* if reserved area in SRAM, try just ioremap */
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size = resource_size(res);
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tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
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} else if (IS_ERR(tdev->tx_mmio)) {
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tdev->tx_mmio = NULL;
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}
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/* If specified, second reg entry is Rx MMIO */
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tdev->rx_mmio = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
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if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
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size = resource_size(res);
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tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
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} else if (IS_ERR(tdev->rx_mmio)) {
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tdev->rx_mmio = tdev->tx_mmio;
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}
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tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
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tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
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if (IS_ERR_OR_NULL(tdev->tx_channel) && IS_ERR_OR_NULL(tdev->rx_channel))
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return -EPROBE_DEFER;
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/* If Rx is not specified but has Rx MMIO, then Rx = Tx */
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if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
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tdev->rx_channel = tdev->tx_channel;
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tdev->dev = &pdev->dev;
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platform_set_drvdata(pdev, tdev);
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spin_lock_init(&tdev->lock);
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mutex_init(&tdev->mutex);
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if (tdev->rx_channel) {
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tdev->rx_buffer = devm_kzalloc(&pdev->dev,
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MBOX_MAX_MSG_LEN, GFP_KERNEL);
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if (!tdev->rx_buffer)
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return -ENOMEM;
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}
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ret = mbox_test_add_debugfs(pdev, tdev);
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if (ret)
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return ret;
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init_waitqueue_head(&tdev->waitq);
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dev_info(&pdev->dev, "Successfully registered\n");
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return 0;
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}
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static void mbox_test_remove(struct platform_device *pdev)
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{
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struct mbox_test_device *tdev = platform_get_drvdata(pdev);
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debugfs_remove_recursive(tdev->root_debugfs_dir);
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if (tdev->tx_channel)
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mbox_free_channel(tdev->tx_channel);
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if (tdev->rx_channel)
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mbox_free_channel(tdev->rx_channel);
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}
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static const struct of_device_id mbox_test_match[] = {
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{ .compatible = "mailbox-test" },
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{},
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};
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MODULE_DEVICE_TABLE(of, mbox_test_match);
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static struct platform_driver mbox_test_driver = {
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.driver = {
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.name = "mailbox_test",
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.of_match_table = mbox_test_match,
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},
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.probe = mbox_test_probe,
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.remove_new = mbox_test_remove,
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};
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module_platform_driver(mbox_test_driver);
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MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
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MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
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MODULE_LICENSE("GPL v2");
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