/* * 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/errno.h>#include <linux/slab.h>#include <linux/list.h>#include <linux/module.h>#include <asm/semaphore.h>#include "dvb_i2c.h"#include "dvb_functions.h"struct dvb_i2c_device {	struct list_head list_head;	struct module *owner;	int (*attach) (struct dvb_i2c_bus *i2c, void **data);	void (*detach) (struct dvb_i2c_bus *i2c, void *data);	void *data;};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;	client->data = dev->data;	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, &dev->data) == 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, dev->data);	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 **data),			     void (*detach) (struct dvb_i2c_bus *i2c, void *data)){	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, void **data)){	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;}