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/*
* 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;
static struct dentry *root_debugfs_dir;
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;
};
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;
return fasync_helper(fd, filp, on, &tdev->async_queue);
}
static ssize_t mbox_test_message_write(struct file *filp,
const char __user *userbuf,
size_t count, loff_t *ppos)
{
struct mbox_test_device *tdev = filp->private_data;
void *data;
int ret;
if (!tdev->tx_channel) {
dev_err(tdev->dev, "Channel cannot do Tx\n");
return -EINVAL;
}
if (count > MBOX_MAX_MSG_LEN) {
dev_err(tdev->dev,
"Message length %zd greater than max allowed %d\n",
count, MBOX_MAX_MSG_LEN);
return -EINVAL;
}
tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
if (!tdev->message)
return -ENOMEM;
ret = copy_from_user(tdev->message, userbuf, count);
if (ret) {
ret = -EFAULT;
goto out;
}
/*
* A separate signal is only of use if there is
* MMIO to subsequently pass the message through
*/
if (tdev->tx_mmio && tdev->signal) {
print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
tdev->signal, MBOX_MAX_SIG_LEN);
data = tdev->signal;
} else
data = tdev->message;
print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
tdev->message, MBOX_MAX_MSG_LEN);
ret = mbox_send_message(tdev->tx_channel, data);
if (ret < 0)
dev_err(tdev->dev, "Failed to send message via mailbox\n");
out:
kfree(tdev->signal);
kfree(tdev->message);
tdev->signal = NULL;
return ret < 0 ? ret : count;
}
static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
{
bool data_ready;
unsigned long flags;
spin_lock_irqsave(&tdev->lock, flags);
data_ready = mbox_data_ready;
spin_unlock_irqrestore(&tdev->lock, flags);
return data_ready;
}
static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct mbox_test_device *tdev = filp->private_data;
unsigned long flags;
char *touser, *ptr;
int l = 0;
int ret;
DECLARE_WAITQUEUE(wait, current);
touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
if (!touser)
return -ENOMEM;
if (!tdev->rx_channel) {
ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
ret = simple_read_from_buffer(userbuf, count, ppos,
touser, ret);
goto kfree_err;
}
add_wait_queue(&tdev->waitq, &wait);
do {
__set_current_state(TASK_INTERRUPTIBLE);
if (mbox_test_message_data_ready(tdev))
break;
if (filp->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto waitq_err;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
goto waitq_err;
}
schedule();
} while (1);
spin_lock_irqsave(&tdev->lock, flags);
ptr = tdev->rx_buffer;
while (l < MBOX_HEXDUMP_MAX_LEN) {
hex_dump_to_buffer(ptr,
MBOX_BYTES_PER_LINE,
MBOX_BYTES_PER_LINE, 1, touser + l,
MBOX_HEXDUMP_LINE_LEN, true);
ptr += MBOX_BYTES_PER_LINE;
l += MBOX_HEXDUMP_LINE_LEN;
*(touser + (l - 1)) = '\n';
}
*(touser + l) = '\0';
memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
mbox_data_ready = false;
spin_unlock_irqrestore(&tdev->lock, flags);
ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
waitq_err:
__set_current_state(TASK_RUNNING);
remove_wait_queue(&tdev->waitq, &wait);
kfree_err:
kfree(touser);
return ret;
}
static __poll_t
mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
{
struct mbox_test_device *tdev = filp->private_data;
poll_wait(filp, &tdev->waitq, wait);
if (mbox_test_message_data_ready(tdev))
return POLLIN | POLLRDNORM;
return 0;
}
static const struct file_operations mbox_test_message_ops = {
.write = mbox_test_message_write,
.read = mbox_test_message_read,
.fasync = mbox_test_message_fasync,
.poll = mbox_test_message_poll,
.open = simple_open,
.llseek = generic_file_llseek,
};
static int mbox_test_add_debugfs(struct platform_device *pdev,
struct mbox_test_device *tdev)
{
if (!debugfs_initialized())
return 0;
root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
if (!root_debugfs_dir)
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