/* Copyright (c) 2008-2010, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*/
/*
* SMD Packet Driver -- Provides userspace interface to SMD packet ports.
*/
#include <linux/slab.h>
#include <linux/cdev.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
#include <linux/poll.h>
#include <mach/msm_smd.h>
#define NUM_SMD_PKT_PORTS 9
#define DEVICE_NAME "smdpkt"
#define MAX_BUF_SIZE 2048
struct smd_pkt_dev {
struct cdev cdev;
struct device *devicep;
struct smd_channel *ch;
int open_count;
struct mutex ch_lock;
struct mutex rx_lock;
struct mutex tx_lock;
wait_queue_head_t ch_read_wait_queue;
wait_queue_head_t ch_opened_wait_queue;
int i;
unsigned char tx_buf[MAX_BUF_SIZE];
unsigned char rx_buf[MAX_BUF_SIZE];
int remote_open;
} *smd_pkt_devp[NUM_SMD_PKT_PORTS];
struct class *smd_pkt_classp;
static dev_t smd_pkt_number;
static int msm_smd_pkt_debug_enable;
module_param_named(debug_enable, msm_smd_pkt_debug_enable,
int, S_IRUGO | S_IWUSR | S_IWGRP);
#ifdef DEBUG
#define D_DUMP_BUFFER(prestr, cnt, buf) do { \
int i; \
if (msm_smd_pkt_debug_enable) { \
pr_debug("%s", prestr); \
for (i = 0; i < cnt; i++) \
pr_debug("%.2x", buf[i]); \
pr_debug("\n"); \
} \
} while (0)
#else
#define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0)
#endif
#ifdef DEBUG
#define DBG(x...) do { \
if (msm_smd_pkt_debug_enable) \
pr_debug(x); \
} while (0)
#else
#define DBG(x...) do {} while (0)
#endif
static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp)
{
int sz;
if (!smd_pkt_devp || !smd_pkt_devp->ch)
return;
sz = smd_cur_packet_size(smd_pkt_devp->ch);
if (sz == 0) {
DBG("no packet\n");
return;
}
if (sz > smd_read_avail(smd_pkt_devp->ch)) {
DBG("incomplete packet\n");
return;
}
DBG("waking up reader\n");
wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue);
}
static int smd_pkt_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
int r, bytes_read;
struct smd_pkt_dev *smd_pkt_devp;
struct smd_channel *chl;
DBG("read %d bytes\n", count);
if (count > MAX_BUF_SIZE)
return -EINVAL;
smd_pkt_devp = file->private_data;
if (!smd_pkt_devp || !smd_pkt_devp->ch)
return -EINVAL;
chl = smd_pkt_devp->ch;
wait_for_packet:
r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue,
(smd_cur_packet_size(chl) > 0 &&
smd_read_avail(chl) >=
smd_cur_packet_size(chl)));
if (r < 0) {
if (r != -ERESTARTSYS)
pr_err("wait returned %d\n", r);
return r;
}
mutex_lock(&smd_pkt_devp->rx_lock);
bytes_read = smd_cur_packet_size(smd_pkt_devp->ch);
if (bytes_read == 0 ||
bytes_read < smd_read_avail(smd_pkt_devp->ch)) {
mutex_unlock(&smd_pkt_devp->rx_lock);
DBG("Nothing to read\n");
goto wait_for_packet;
}
if (bytes_read > count) {
mutex_unlock(&smd_pkt_devp->rx_lock);
pr_info("packet size %d > buffer size %d", bytes_read, count);
return -EINVAL;
}
r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read);
if (r != bytes_read) {
mutex_unlock(&smd_pkt_devp->rx_lock);
pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r);
return -EIO;
}
D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf);
r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read);
mutex_unlock(&smd_pkt_devp->rx_lock);
if (r) {
pr_err("copy_to_user failed %d\n", r);
return -EFAULT;
}
DBG("read complete %d bytes\n", bytes_read);
check_and_wakeup_reader(smd_pkt_devp);
return bytes_read;
}
static int smd_pkt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
int r;
struct smd_pkt_dev *smd_pkt_devp;
if (count > MAX_BUF_SIZE)
return -EINVAL;
DBG("writting %d bytes\n", count);
smd_pkt_devp = file->private_data;
if (!smd_pkt_devp || !smd_pkt_devp->ch)
return -EINVAL;
mutex_lock(&smd_pkt_devp->tx_lock);
if (smd_write_avail(smd_pkt_devp->ch) < count) {
mutex_unlock(&smd_pkt_devp->tx_lock);
DBG("Not enough space to write\n");
return -ENOMEM;
}
D_DUMP_BUFFER("write: ", count, buf);
r = copy_from_user(smd_pkt_devp->tx_buf, buf, count);
if (r) {
mutex_unlock(&smd_pkt_devp->tx_lock);
pr_err("copy_from_user failed %d\n", r);
return -EFAULT;
}
r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count);
if (r != count) {
mutex_unlock(&smd_pkt_devp->tx_lock);
pr_err("smd_write failed to write %d bytes: %d.\n", count, r);
return -EIO;
}
mutex_unlock(&smd_pkt_devp->tx_lock);
DBG("wrote %d bytes\n", count);
return count;
}
static unsigned int smd_pkt_poll(struct file *file, poll_table *wait)
{
struct smd_pkt_dev *smd_pkt_devp;
unsigned int mask = 0;
smd_pkt_devp = file->private_data;
if (!smd_pkt_devp)
return POLLERR;
DBG("poll waiting\n");
poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait);
if (smd_read_avail(smd_pkt_devp->ch))
mask |= POLLIN | POLLRDNORM;
DBG("poll return\n");
return mask;
}
static void smd_pkt_ch_notify(void *priv, unsigned event)
{
struct smd_pkt_dev *smd_pkt_devp = priv;
if (smd_pkt_devp->ch == 0)
return;
switch (event) {
case SMD_EVENT_DATA:
DBG("data\n");
check_and_wakeup_reader(smd_pkt_devp);
break;
case SMD_EVENT_OPEN:
DBG("remote open\n");
smd_pkt_devp->remote_open = 1;
wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue);
break;
case SMD_EVENT_CLOSE:
smd_pkt_devp->remote_open = 0;
pr_info("remote closed\n");
break;
default:
pr_err("unknown event %d\n", event);
break;
}
}
static char *smd_pkt_dev_name[] = {
"smdcntl0",
"smdcntl1",
"smdcntl2",
"smdcntl3",
"smdcntl4",
"smdcntl5",
"smdcntl6",
"smdcntl7",
"smd22",
};
static char *smd_ch_name[] = {
"DATA5_CNTL",
"DATA6_CNTL",
"DATA7_CNTL",
"DATA8_CNTL",
"DATA9_CNTL",
"DATA12_CNTL",
"DATA13_CNTL",
"DATA14_CNTL",
"DATA22",
};
static int smd_pkt_open(struct inode *inode, struct file *file)
{
int r = 0;
struct smd_pkt_dev *smd_pkt_devp;
smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev);
if (!smd_pkt_devp)
return -EINVAL;
file->private_data = smd_pkt_devp;
mutex_lock(&smd_pkt_devp->ch_lock);
if (smd_pkt_devp->open_count == 0) {
r = smd_open(smd_ch_name[smd_pkt_devp->i],
&smd_pkt_devp->ch, smd_pkt_devp,
smd_pkt_ch_notify);
if (r < 0) {
pr_err("smd_open failed for %s, %d\n",
smd_ch_name[smd_pkt_devp->i], r);
goto out;
}
r = wait_event_interruptible_timeout(
smd_pkt_devp->ch_opened_wait_queue,
smd_pkt_devp->remote_open,
msecs_to_jiffies(2 * HZ));
if (r == 0)
r = -ETIMEDOUT;
if (r < 0) {
pr_err("wait returned %d\n", r);
smd_close(smd_pkt_devp->ch);
smd_pkt_devp->ch = 0;
} else {
smd_pkt_devp->open_count++;
r = 0;
}
}
out:
mutex_unlock(&smd_pkt_devp->ch_lock);
return r;
}
static int smd_pkt_release(struct inode *inode, struct file *file)
{
int r = 0;
struct smd_pkt_dev *smd_pkt_devp = file->private_data;
if (!smd_pkt_devp)
return -EINVAL;
mutex_lock(&smd_pkt_devp->ch_lock);
if (--smd_pkt_devp->open_count == 0) {
r = smd_close(smd_pkt_devp->ch);
smd_pkt_devp->ch = 0;
}
mutex_unlock(&smd_pkt_devp->ch_lock);
return r;
}
static const struct file_operations smd_pkt_fops = {
.owner = THIS_MODULE,
.open = smd_pkt_open,
.release = smd_pkt_release,
.read = smd_pkt_read,
.write = smd_pkt_write,
.poll = smd_pkt_poll,
};
static int __init smd_pkt_init(void)
{
int i;
int r;
r = alloc_chrdev_region(&smd_pkt_number, 0,
NUM_SMD_PKT_PORTS, DEVICE_NAME);
if (r) {
pr_err("alloc_chrdev_region() failed %d\n", r);
return r;
}
smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME);
if (IS_ERR(smd_pkt_classp)) {
r = PTR_ERR(smd_pkt_classp);
pr_err("class_create() failed %d\n", r);
goto unreg_chardev;
}
for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) {
smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev),
GFP_KERNEL);
if (!smd_pkt_devp[i]) {
pr_err("kmalloc() failed\n");
goto clean_cdevs;
}
smd_pkt_devp[i]->i = i;
init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue);
smd_pkt_devp[i]->remote_open = 0;
init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue);
mutex_init(&smd_pkt_devp[i]->ch_lock);
mutex_init(&smd_pkt_devp[i]->rx_lock);
mutex_init(&smd_pkt_devp[i]->tx_lock);
cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops);
smd_pkt_devp[i]->cdev.owner = THIS_MODULE;
r = cdev_add(&smd_pkt_devp[i]->cdev,
(smd_pkt_number + i), 1);
if (r) {
pr_err("cdev_add() failed %d\n", r);
kfree(smd_pkt_devp[i]);
goto clean_cdevs;
}
smd_pkt_devp[i]->devicep =
device_create(smd_pkt_classp, NULL,
(smd_pkt_number + i), NULL,
smd_pkt_dev_name[i]);
if (IS_ERR(smd_pkt_devp[i]->devicep)) {
r = PTR_ERR(smd_pkt_devp[i]->devicep);
pr_err("device_create() failed %d\n", r);
cdev_del(&smd_pkt_devp[i]->cdev);
kfree(smd_pkt_devp[i]);
goto clean_cdevs;
}
}
pr_info("SMD Packet Port Driver Initialized.\n");
return 0;
clean_cdevs:
if (i > 0) {
while (--i >= 0) {
mutex_destroy(&smd_pkt_devp[i]->ch_lock);
mutex_destroy(&smd_pkt_devp[i]->rx_lock);
mutex_destroy(&smd_pkt_devp[i]->tx_lock);
cdev_del(&smd_pkt_devp[i]->cdev);
kfree(smd_pkt_devp[i]);
device_destroy(smd_pkt_classp,
MKDEV(MAJOR(smd_pkt_number), i));
}
}
class_destroy(smd_pkt_classp);
unreg_chardev:
unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS);
return r;
}
module_init(smd_pkt_init);
static void __exit smd_pkt_cleanup(void)
{
int i;
for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) {
mutex_destroy(&smd_pkt_devp[i]->ch_lock);
mutex_destroy(&smd_pkt_devp[i]->rx_lock);
mutex_destroy(&smd_pkt_devp[i]->tx_lock);
cdev_del(&smd_pkt_devp[i]->cdev);
kfree(smd_pkt_devp[i]);
device_destroy(smd_pkt_classp,
MKDEV(MAJOR(smd_pkt_number), i));
}
class_destroy(smd_pkt_classp);
unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS);
}
module_exit(smd_pkt_cleanup);
MODULE_DESCRIPTION("MSM Shared Memory Packet Port");
MODULE_LICENSE("GPL v2");
