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|
/* -----------------------------------------------------------------------------
* Copyright (c) 2011 Ozmo Inc
* Released under the GNU General Public License Version 2 (GPLv2).
* -----------------------------------------------------------------------------
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include "ozdbg.h"
#include "ozprotocol.h"
#include "ozappif.h"
#include "ozeltbuf.h"
#include "ozpd.h"
#include "ozproto.h"
#include "ozcdev.h"
/*------------------------------------------------------------------------------
*/
#define OZ_RD_BUF_SZ 256
struct oz_cdev {
dev_t devnum;
struct cdev cdev;
wait_queue_head_t rdq;
spinlock_t lock;
u8 active_addr[ETH_ALEN];
struct oz_pd *active_pd;
};
/* Per PD context for the serial service stored in the PD. */
struct oz_serial_ctx {
atomic_t ref_count;
u8 tx_seq_num;
u8 rx_seq_num;
u8 rd_buf[OZ_RD_BUF_SZ];
int rd_in;
int rd_out;
};
/*------------------------------------------------------------------------------
*/
static struct oz_cdev g_cdev;
static struct class *g_oz_class;
/*------------------------------------------------------------------------------
* Context: process and softirq
*/
static struct oz_serial_ctx *oz_cdev_claim_ctx(struct oz_pd *pd)
{
struct oz_serial_ctx *ctx;
spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
if (ctx)
atomic_inc(&ctx->ref_count);
spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
return ctx;
}
/*------------------------------------------------------------------------------
* Context: softirq or process
*/
static void oz_cdev_release_ctx(struct oz_serial_ctx *ctx)
{
if (atomic_dec_and_test(&ctx->ref_count)) {
oz_dbg(ON, "Dealloc serial context\n");
kfree(ctx);
}
}
/*------------------------------------------------------------------------------
* Context: process
*/
static int oz_cdev_open(struct inode *inode, struct file *filp)
{
struct oz_cdev *dev = container_of(inode->i_cdev, struct oz_cdev, cdev);
oz_dbg(ON, "major = %d minor = %d\n", imajor(inode), iminor(inode));
filp->private_data = dev;
return 0;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static int oz_cdev_release(struct inode *inode, struct file *filp)
{
return 0;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static ssize_t oz_cdev_read(struct file *filp, char __user *buf, size_t count,
loff_t *fpos)
{
int n;
int ix;
struct oz_pd *pd;
struct oz_serial_ctx *ctx;
spin_lock_bh(&g_cdev.lock);
pd = g_cdev.active_pd;
if (pd)
oz_pd_get(pd);
spin_unlock_bh(&g_cdev.lock);
if (pd == NULL)
return -1;
ctx = oz_cdev_claim_ctx(pd);
if (ctx == NULL)
goto out2;
n = ctx->rd_in - ctx->rd_out;
if (n < 0)
n += OZ_RD_BUF_SZ;
if (count > n)
count = n;
ix = ctx->rd_out;
n = OZ_RD_BUF_SZ - ix;
if (n > count)
n = count;
if (copy_to_user(buf, &ctx->rd_buf[ix], n)) {
count = 0;
goto out1;
}
ix += n;
if (ix == OZ_RD_BUF_SZ)
ix = 0;
if (n < count) {
if (copy_to_user(&buf[n], ctx->rd_buf, count-n)) {
count = 0;
goto out1;
}
ix = count-n;
}
ctx->rd_out = ix;
out1:
oz_cdev_release_ctx(ctx);
out2:
oz_pd_put(pd);
return count;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static ssize_t oz_cdev_write(struct file *filp, const char __user *buf,
size_t count, loff_t *fpos)
{
struct oz_pd *pd;
struct oz_elt_buf *eb;
struct oz_elt_info *ei;
struct oz_elt *elt;
struct oz_app_hdr *app_hdr;
struct oz_serial_ctx *ctx;
spin_lock_bh(&g_cdev.lock);
pd = g_cdev.active_pd;
if (pd)
oz_pd_get(pd);
spin_unlock_bh(&g_cdev.lock);
if (pd == NULL)
return -1;
eb = &pd->elt_buff;
ei = oz_elt_info_alloc(eb);
if (ei == NULL) {
count = 0;
goto out;
}
elt = (struct oz_elt *)ei->data;
app_hdr = (struct oz_app_hdr *)(elt+1);
elt->length = sizeof(struct oz_app_hdr) + count;
elt->type = OZ_ELT_APP_DATA;
ei->app_id = OZ_APPID_SERIAL;
ei->length = elt->length + sizeof(struct oz_elt);
app_hdr->app_id = OZ_APPID_SERIAL;
if (copy_from_user(app_hdr+1, buf, count))
goto out;
spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
if (ctx) {
app_hdr->elt_seq_num = ctx->tx_seq_num++;
if (ctx->tx_seq_num == 0)
ctx->tx_seq_num = 1;
spin_lock(&eb->lock);
if (oz_queue_elt_info(eb, 0, 0, ei) == 0)
ei = NULL;
spin_unlock(&eb->lock);
}
spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
out:
if (ei) {
count = 0;
spin_lock_bh(&eb->lock);
oz_elt_info_free(eb, ei);
spin_unlock_bh(&eb->lock);
}
oz_pd_put(pd);
return count;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static int oz_set_active_pd(const u8 *addr)
{
int rc = 0;
struct oz_pd *pd;
struct oz_pd *old_pd;
pd = oz_pd_find(addr);
if (pd) {
spin_lock_bh(&g_cdev.lock);
memcpy(g_cdev.active_addr, addr, ETH_ALEN);
old_pd = g_cdev.active_pd;
g_cdev.active_pd = pd;
spin_unlock_bh(&g_cdev.lock);
if (old_pd)
oz_pd_put(old_pd);
} else {
if (is_zero_ether_addr(addr)) {
spin_lock_bh(&g_cdev.lock);
pd = g_cdev.active_pd;
g_cdev.active_pd = NULL;
memset(g_cdev.active_addr, 0,
sizeof(g_cdev.active_addr));
spin_unlock_bh(&g_cdev.lock);
if (pd)
oz_pd_put(pd);
} else {
rc = -1;
}
}
return rc;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static long oz_cdev_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
int rc = 0;
if (_IOC_TYPE(cmd) != OZ_IOCTL_MAGIC)
return -ENOTTY;
if (_IOC_NR(cmd) > OZ_IOCTL_MAX)
return -ENOTTY;
if (_IOC_DIR(cmd) & _IOC_READ)
rc = !access_ok(VERIFY_WRITE, (void __user *)arg,
_IOC_SIZE(cmd));
else if (_IOC_DIR(cmd) & _IOC_WRITE)
rc = !access_ok(VERIFY_READ, (void __user *)arg,
_IOC_SIZE(cmd));
if (rc)
return -EFAULT;
switch (cmd) {
case OZ_IOCTL_GET_PD_LIST: {
struct oz_pd_list list;
oz_dbg(ON, "OZ_IOCTL_GET_PD_LIST\n");
memset(&list, 0, sizeof(list));
list.count = oz_get_pd_list(list.addr, OZ_MAX_PDS);
if (copy_to_user((void __user *)arg, &list,
sizeof(list)))
return -EFAULT;
}
break;
case OZ_IOCTL_SET_ACTIVE_PD: {
u8 addr[ETH_ALEN];
oz_dbg(ON, "OZ_IOCTL_SET_ACTIVE_PD\n");
if (copy_from_user(addr, (void __user *)arg, ETH_ALEN))
return -EFAULT;
rc = oz_set_active_pd(addr);
}
break;
case OZ_IOCTL_GET_ACTIVE_PD: {
u8 addr[ETH_ALEN];
oz_dbg(ON, "OZ_IOCTL_GET_ACTIVE_PD\n");
spin_lock_bh(&g_cdev.lock);
memcpy(addr, g_cdev.active_addr, ETH_ALEN);
spin_unlock_bh(&g_cdev.lock);
if (copy_to_user((void __user *)arg, addr, ETH_ALEN))
return -EFAULT;
}
break;
case OZ_IOCTL_ADD_BINDING:
case OZ_IOCTL_REMOVE_BINDING: {
struct oz_binding_info b;
if (copy_from_user(&b, (void __user *)arg,
sizeof(struct oz_binding_info))) {
return -EFAULT;
}
/* Make sure name is null terminated. */
b.name[OZ_MAX_BINDING_LEN-1] = 0;
if (cmd == OZ_IOCTL_ADD_BINDING)
oz_binding_add(b.name);
else
oz_binding_remove(b.name);
}
break;
}
return rc;
}
/*------------------------------------------------------------------------------
* Context: process
*/
static unsigned int oz_cdev_poll(struct file *filp, poll_table *wait)
{
unsigned int ret = 0;
struct oz_cdev *dev = filp->private_data;
oz_dbg(ON, "Poll called wait = %p\n", wait);
spin_lock_bh(&dev->lock);
if (dev->active_pd) {
struct oz_serial_ctx *ctx = oz_cdev_claim_ctx(dev->active_pd);
if (ctx) {
if (ctx->rd_in != ctx->rd_out)
ret |= POLLIN | POLLRDNORM;
oz_cdev_release_ctx(ctx);
}
}
spin_unlock_bh(&dev->lock);
if (wait)
poll_wait(filp, &dev->rdq, wait);
return ret;
}
/*------------------------------------------------------------------------------
*/
static const struct file_operations oz_fops = {
.owner = THIS_MODULE,
.open = oz_cdev_open,
.release = oz_cdev_release,
.read = oz_cdev_read,
.write = oz_cdev_write,
.unlocked_ioctl = oz_cdev_ioctl,
.poll = oz_cdev_poll
};
/*------------------------------------------------------------------------------
* Context: process
*/
int oz_cdev_register(void)
{
int err;
struct device *dev;
memset(&g_cdev, 0, sizeof(g_cdev));
err = alloc_chrdev_region(&g_cdev.devnum, 0, 1, "ozwpan");
if (err < 0)
return err;
oz_dbg(ON, "Alloc dev number %d:%d\n",
MAJOR(g_cdev.devnum), MINOR(g_cdev.devnum));
cdev_init(&g_cdev.cdev, &oz_fops);
g_cdev.cdev.owner = THIS_MODULE;
g_cdev.cdev.ops = &oz_fops;
spin_lock_init(&g_cdev.lock);
init_waitqueue_head(&g_cdev.rdq);
err = cdev_add(&g_cdev.cdev, g_cdev.devnum, 1);
if (err < 0) {
oz_dbg(ON, "Failed to add cdev\n");
goto unregister;
}
g_oz_class = class_create(THIS_MODULE, "ozmo_wpan");
if (IS_ERR(g_oz_class)) {
oz_dbg(ON, "Failed to register ozmo_wpan class\n");
err = PTR_ERR(g_oz_class);
goto delete;
}
dev = device_create(g_oz_class, NULL, g_cdev.devnum, NULL, "ozwpan");
if (IS_ERR(dev)) {
oz_dbg(ON, "Failed to create sysfs entry for cdev\n");
err = PTR_ERR(dev);
goto delete;
}
return 0;
delete:
cdev_del(&g_cdev.cdev);
unregister:
unregister_chrdev_region(g_cdev.devnum, 1);
return err;
}
/*------------------------------------------------------------------------------
* Context: process
*/
int oz_cdev_deregister(void)
{
cdev_del(&g_cdev.cdev);
unregister_chrdev_region(g_cdev.devnum, 1);
if (g_oz_class) {
device_destroy(g_oz_class, g_cdev.devnum);
class_destroy(g_oz_class);
}
return 0;
}
/*------------------------------------------------------------------------------
* Context: process
*/
int oz_cdev_init(void)
{
oz_app_enable(OZ_APPID_SERIAL, 1);
return 0;
}
/*------------------------------------------------------------------------------
* Context: process
*/
void oz_cdev_term(void)
{
oz_app_enable(OZ_APPID_SERIAL, 0);
}
/*------------------------------------------------------------------------------
* Context: softirq-serialized
*/
int oz_cdev_start(struct oz_pd *pd, int resume)
{
struct oz_serial_ctx *ctx;
struct oz_serial_ctx *old_ctx;
if (resume) {
oz_dbg(ON, "Serial service resumed\n");
return 0;
}
ctx = kzalloc(sizeof(struct oz_serial_ctx), GFP_ATOMIC);
if (ctx == NULL)
return -ENOMEM;
atomic_set(&ctx->ref_count, 1);
ctx->tx_seq_num = 1;
spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
old_ctx = pd->app_ctx[OZ_APPID_SERIAL-1];
if (old_ctx) {
spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
kfree(ctx);
} else {
pd->app_ctx[OZ_APPID_SERIAL-1] = ctx;
spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
}
spin_lock(&g_cdev.lock);
if ((g_cdev.active_pd == NULL) &&
(memcmp(pd->mac_addr, g_cdev.active_addr, ETH_ALEN) == 0)) {
oz_pd_get(pd);
g_cdev.active_pd = pd;
oz_dbg(ON, "Active PD arrived\n");
}
spin_unlock(&g_cdev.lock);
oz_dbg(ON, "Serial service started\n");
return 0;
}
/*------------------------------------------------------------------------------
* Context: softirq or process
*/
void oz_cdev_stop(struct oz_pd *pd, int pause)
{
struct oz_serial_ctx *ctx;
if (pause) {
oz_dbg(ON, "Serial service paused\n");
return;
}
spin_lock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
ctx = (struct oz_serial_ctx *)pd->app_ctx[OZ_APPID_SERIAL-1];
pd->app_ctx[OZ_APPID_SERIAL-1] = NULL;
spin_unlock_bh(&pd->app_lock[OZ_APPID_SERIAL-1]);
if (ctx)
oz_cdev_release_ctx(ctx);
spin_lock(&g_cdev.lock);
if (pd == g_cdev.active_pd)
g_cdev.active_pd = NULL;
else
pd = NULL;
spin_unlock(&g_cdev.lock);
if (pd) {
oz_pd_put(pd);
oz_dbg(ON, "Active PD departed\n");
}
oz_dbg(ON, "Serial service stopped\n");
}
/*------------------------------------------------------------------------------
* Context: softirq-serialized
*/
void oz_cdev_rx(struct oz_pd *pd, struct oz_elt *elt)
{
struct oz_serial_ctx *ctx;
struct oz_app_hdr *app_hdr;
u8 *data;
int len;
int space;
int copy_sz;
int ix;
ctx = oz_cdev_claim_ctx(pd);
if (ctx == NULL) {
oz_dbg(ON, "Cannot claim serial context\n");
return;
}
app_hdr = (struct oz_app_hdr *)(elt+1);
/* If sequence number is non-zero then check it is not a duplicate.
*/
if (app_hdr->elt_seq_num != 0) {
if (((ctx->rx_seq_num - app_hdr->elt_seq_num) & 0x80) == 0) {
/* Reject duplicate element. */
oz_dbg(ON, "Duplicate element:%02x %02x\n",
app_hdr->elt_seq_num, ctx->rx_seq_num);
goto out;
}
}
ctx->rx_seq_num = app_hdr->elt_seq_num;
len = elt->length - sizeof(struct oz_app_hdr);
data = ((u8 *)(elt+1)) + sizeof(struct oz_app_hdr);
if (len <= 0)
goto out;
space = ctx->rd_out - ctx->rd_in - 1;
if (space < 0)
space += OZ_RD_BUF_SZ;
if (len > space) {
oz_dbg(ON, "Not enough space:%d %d\n", len, space);
len = space;
}
ix = ctx->rd_in;
copy_sz = OZ_RD_BUF_SZ - ix;
if (copy_sz > len)
copy_sz = len;
memcpy(&ctx->rd_buf[ix], data, copy_sz);
len -= copy_sz;
ix += copy_sz;
if (ix == OZ_RD_BUF_SZ)
ix = 0;
if (len) {
memcpy(ctx->rd_buf, data+copy_sz, len);
ix = len;
}
ctx->rd_in = ix;
wake_up(&g_cdev.rdq);
out:
oz_cdev_release_ctx(ctx);
}
|