File:
[DVB] /
DVB /
driver /
dvb_i2c.c
Revision
1.7:
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Mon Nov 18 21:18:52 2002 UTC (21 years, 6 months ago) by
holger
Branches:
MAIN
CVS tags:
branch_f_092003,
branch_20040513,
branch_20031217,
LINUXTV-DVB-1_0_1,
LINUXTV-DVB-1_0_0_pre3,
LINUXTV-DVB-1_0_0_pre2,
LINUXTV-DVB-1_0_0_pre1,
LINUXTV-DVB-1_0_0,
HEAD
make i2c messages const pointers
/*
* dvb_i2c.h: simplified i2c interface for DVB adapters to get rid of i2c-core.c
*
* Copyright (C) 2002 Holger Waechtler for convergence integrated media GmbH
*
* 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.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* Or, point your browser to http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include "compat.h"
#include "dvb_i2c.h"
struct dvb_i2c_device {
struct list_head list_head;
struct module *owner;
int (*attach) (struct dvb_i2c_bus *i2c);
void (*detach) (struct dvb_i2c_bus *i2c);
};
LIST_HEAD(dvb_i2c_buslist);
LIST_HEAD(dvb_i2c_devicelist);
DECLARE_MUTEX(dvb_i2c_mutex);
static
int register_i2c_client (struct dvb_i2c_bus *i2c, struct dvb_i2c_device *dev)
{
struct dvb_i2c_device *client;
if (!(client = kmalloc (sizeof (struct dvb_i2c_device), GFP_KERNEL)))
return -ENOMEM;
client->detach = dev->detach;
client->owner = dev->owner;
INIT_LIST_HEAD(&client->list_head);
list_add_tail (&client->list_head, &i2c->client_list);
return 0;
}
static
void try_attach_device (struct dvb_i2c_bus *i2c, struct dvb_i2c_device *dev)
{
if (dev->owner) {
if (!try_module_get(dev->owner))
return;
}
if (dev->attach (i2c) == 0) {
register_i2c_client (i2c, dev);
} else {
if (dev->owner)
module_put (dev->owner);
}
}
static
void detach_device (struct dvb_i2c_bus *i2c, struct dvb_i2c_device *dev)
{
dev->detach (i2c);
if (dev->owner)
module_put (dev->owner);
}
static
void unregister_i2c_client_from_bus (struct dvb_i2c_device *dev,
struct dvb_i2c_bus *i2c)
{
struct list_head *entry, *n;
list_for_each_safe (entry, n, &i2c->client_list) {
struct dvb_i2c_device *client;
client = list_entry (entry, struct dvb_i2c_device, list_head);
if (client->detach == dev->detach) {
list_del (entry);
detach_device (i2c, dev);
}
}
}
static
void unregister_i2c_client_from_all_busses (struct dvb_i2c_device *dev)
{
struct list_head *entry, *n;
list_for_each_safe (entry, n, &dvb_i2c_buslist) {
struct dvb_i2c_bus *i2c;
i2c = list_entry (entry, struct dvb_i2c_bus, list_head);
unregister_i2c_client_from_bus (dev, i2c);
}
}
static
void unregister_all_clients_from_bus (struct dvb_i2c_bus *i2c)
{
struct list_head *entry, *n;
list_for_each_safe (entry, n, &(i2c->client_list)) {
struct dvb_i2c_device *dev;
dev = list_entry (entry, struct dvb_i2c_device, list_head);
unregister_i2c_client_from_bus (dev, i2c);
}
}
static
void probe_device_on_all_busses (struct dvb_i2c_device *dev)
{
struct list_head *entry;
list_for_each (entry, &dvb_i2c_buslist) {
struct dvb_i2c_bus *i2c;
i2c = list_entry (entry, struct dvb_i2c_bus, list_head);
try_attach_device (i2c, dev);
}
}
static
void probe_devices_on_bus (struct dvb_i2c_bus *i2c)
{
struct list_head *entry;
list_for_each (entry, &dvb_i2c_devicelist) {
struct dvb_i2c_device *dev;
dev = list_entry (entry, struct dvb_i2c_device, list_head);
try_attach_device (i2c, dev);
}
}
static
struct dvb_i2c_bus* dvb_find_i2c_bus (int (*xfer) (struct dvb_i2c_bus *i2c,
const struct i2c_msg msgs[],
int num),
struct dvb_adapter *adapter,
int id)
{
struct list_head *entry;
list_for_each (entry, &dvb_i2c_buslist) {
struct dvb_i2c_bus *i2c;
i2c = list_entry (entry, struct dvb_i2c_bus, list_head);
if (i2c->xfer == xfer && i2c->adapter == adapter && i2c->id == id)
return i2c;
}
return NULL;
}
struct dvb_i2c_bus*
dvb_register_i2c_bus (int (*xfer) (struct dvb_i2c_bus *i2c,
const struct i2c_msg *msgs, int num),
void *data, struct dvb_adapter *adapter, int id)
{
struct dvb_i2c_bus *i2c;
if (down_interruptible (&dvb_i2c_mutex))
return NULL;
if (!(i2c = kmalloc (sizeof (struct dvb_i2c_bus), GFP_KERNEL)))
return NULL;
INIT_LIST_HEAD(&i2c->list_head);
INIT_LIST_HEAD(&i2c->client_list);
i2c->xfer = xfer;
i2c->data = data;
i2c->adapter = adapter;
i2c->id = id;
probe_devices_on_bus (i2c);
list_add_tail (&i2c->list_head, &dvb_i2c_buslist);
up (&dvb_i2c_mutex);
return i2c;
}
void dvb_unregister_i2c_bus (int (*xfer) (struct dvb_i2c_bus *i2c,
const struct i2c_msg msgs[], int num),
struct dvb_adapter *adapter, int id)
{
struct dvb_i2c_bus *i2c;
down (&dvb_i2c_mutex);
if ((i2c = dvb_find_i2c_bus (xfer, adapter, id))) {
unregister_all_clients_from_bus (i2c);
list_del (&i2c->list_head);
kfree (i2c);
}
up (&dvb_i2c_mutex);
}
int dvb_register_i2c_device (struct module *owner,
int (*attach) (struct dvb_i2c_bus *i2c),
void (*detach) (struct dvb_i2c_bus *i2c))
{
struct dvb_i2c_device *entry;
if (down_interruptible (&dvb_i2c_mutex))
return -ERESTARTSYS;
if (!(entry = kmalloc (sizeof (struct dvb_i2c_device), GFP_KERNEL)))
return -ENOMEM;
entry->owner = owner;
entry->attach = attach;
entry->detach = detach;
INIT_LIST_HEAD(&entry->list_head);
probe_device_on_all_busses (entry);
list_add_tail (&entry->list_head, &dvb_i2c_devicelist);
up (&dvb_i2c_mutex);
return 0;
}
int dvb_unregister_i2c_device (int (*attach) (struct dvb_i2c_bus *i2c))
{
struct list_head *entry, *n;
down (&dvb_i2c_mutex);
list_for_each_safe (entry, n, &dvb_i2c_devicelist) {
struct dvb_i2c_device *dev;
dev = list_entry (entry, struct dvb_i2c_device, list_head);
if (dev->attach == attach) {
list_del (entry);
unregister_i2c_client_from_all_busses (dev);
kfree (entry);
up (&dvb_i2c_mutex);
return 0;
}
}
up (&dvb_i2c_mutex);
return -EINVAL;
}
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