All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> */
-/* $Id: i2c-core.c,v 1.89 2002/11/03 16:47:16 mds Exp $ */
+/* $Id: i2c-core.c,v 1.95 2003/01/22 05:25:08 kmalkki Exp $ */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
-#include <linux/config.h>
#include <linux/i2c.h>
-
-/* ----- compatibility stuff ----------------------------------------------- */
-
-#include <linux/version.h>
#include <linux/init.h>
-
#include <asm/uaccess.h>
-/* ----- global defines ---------------------------------------------------- */
-
-/* exclusive access to the bus */
-#define I2C_LOCK(adap) down(&adap->lock)
-#define I2C_UNLOCK(adap) up(&adap->lock)
-
-#define ADAP_LOCK() down(&adap_lock)
-#define ADAP_UNLOCK() up(&adap_lock)
-
-#define DRV_LOCK() down(&driver_lock)
-#define DRV_UNLOCK() up(&driver_lock)
#define DEB(x) if (i2c_debug>=1) x;
#define DEB2(x) if (i2c_debug>=2) x;
-/* ----- global variables -------------------------------------------------- */
-
-/**** lock for writing to global variables: the adapter & driver list */
-static DECLARE_MUTEX(adap_lock);
-static DECLARE_MUTEX(driver_lock);
-
-/**** adapter list */
static struct i2c_adapter *adapters[I2C_ADAP_MAX];
-
-/**** drivers list */
static struct i2c_driver *drivers[I2C_DRIVER_MAX];
+static DECLARE_MUTEX(core_lists);
/**** debug level */
static int i2c_debug;
*/
int i2c_add_adapter(struct i2c_adapter *adap)
{
- int i,j,res;
+ int res = 0, i, j;
- ADAP_LOCK();
+ down(&core_lists);
for (i = 0; i < I2C_ADAP_MAX; i++)
if (NULL == adapters[i])
break;
printk(KERN_WARNING
" i2c-core.o: register_adapter(%s) - enlarge I2C_ADAP_MAX.\n",
adap->name);
- goto fail;
+ res = -ENOMEM;
+ goto out_unlock;
}
- adapters[i] = adap;
- ADAP_UNLOCK();
-
- /* init data types */
- init_MUTEX(&adap->lock);
-
res = i2cproc_register(adap, i);
if (res)
- return res;
+ goto out_unlock;
+
+ adapters[i] = adap;
+
+ init_MUTEX(&adap->bus);
+ init_MUTEX(&adap->list);
/* inform drivers of new adapters */
- DRV_LOCK();
for (j=0;j<I2C_DRIVER_MAX;j++)
if (drivers[j]!=NULL &&
(drivers[j]->flags&(I2C_DF_NOTIFY|I2C_DF_DUMMY)))
/* We ignore the return code; if it fails, too bad */
drivers[j]->attach_adapter(adap);
- DRV_UNLOCK();
+ up(&core_lists);
DEB(printk(KERN_DEBUG "i2c-core.o: adapter %s registered as adapter %d.\n",
adap->name,i));
- return 0;
-
- fail:
- ADAP_UNLOCK();
- return -ENOMEM;
+ out_unlock:
+ up(&core_lists);
+ return res;;
}
int i2c_del_adapter(struct i2c_adapter *adap)
{
- int i,j,res;
-
- ADAP_LOCK();
+ int res = 0, i, j;
+ down(&core_lists);
for (i = 0; i < I2C_ADAP_MAX; i++)
if (adap == adapters[i])
break;
printk( KERN_WARNING "i2c-core.o: unregister_adapter adap [%s] not found.\n",
adap->name);
res = -ENODEV;
- goto ERROR0;
+ goto out_unlock;
}
/* DUMMY drivers do not register their clients, so we have to
* *detach* it! Of course, each dummy driver should know about
* this or hell will break loose...
*/
- DRV_LOCK();
for (j = 0; j < I2C_DRIVER_MAX; j++)
if (drivers[j] && (drivers[j]->flags & I2C_DF_DUMMY))
if ((res = drivers[j]->attach_adapter(adap))) {
printk(KERN_WARNING "i2c-core.o: can't detach adapter %s "
"while detaching driver %s: driver not "
"detached!",adap->name,drivers[j]->name);
- goto ERROR1;
+ goto out_unlock;
}
- DRV_UNLOCK();
-
/* detach any active clients. This must be done first, because
* it can fail; in which case we give upp. */
for (j=0;j<I2C_CLIENT_MAX;j++) {
struct i2c_client *client = adap->clients[j];
- if (client!=NULL)
+ if (client!=NULL) {
/* detaching devices is unconditional of the set notify
* flag, as _all_ clients that reside on the adapter
* must be deleted, as this would cause invalid states.
"unregistered, because client at "
"address %02x can't be detached. ",
adap->name, client->addr);
- goto ERROR0;
+ goto out_unlock;
}
+ }
}
i2cproc_remove(i);
adapters[i] = NULL;
-
- ADAP_UNLOCK();
+
DEB(printk(KERN_DEBUG "i2c-core.o: adapter unregistered: %s\n",adap->name));
- return 0;
-ERROR0:
- ADAP_UNLOCK();
- return res;
-ERROR1:
- DRV_UNLOCK();
+ out_unlock:
+ up(&core_lists);
return res;
}
int i2c_add_driver(struct i2c_driver *driver)
{
- int i;
- DRV_LOCK();
+ int res = 0, i;
+
+ down(&core_lists);
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (NULL == drivers[i])
break;
" i2c-core.o: register_driver(%s) "
"- enlarge I2C_DRIVER_MAX.\n",
driver->name);
- DRV_UNLOCK();
- return -ENOMEM;
+ res = -ENOMEM;
+ goto out_unlock;
}
drivers[i] = driver;
- DRV_UNLOCK(); /* driver was successfully added */
-
DEB(printk(KERN_DEBUG "i2c-core.o: driver %s registered.\n",driver->name));
- ADAP_LOCK();
-
/* now look for instances of driver on our adapters
*/
if (driver->flags& (I2C_DF_NOTIFY|I2C_DF_DUMMY)) {
- for (i=0;i<I2C_ADAP_MAX;i++)
+ for (i=0;i<I2C_ADAP_MAX;i++) {
if (adapters[i]!=NULL)
/* Ignore errors */
driver->attach_adapter(adapters[i]);
+ }
}
- ADAP_UNLOCK();
- return 0;
+
+ out_unlock:
+ up(&core_lists);
+ return res;
}
int i2c_del_driver(struct i2c_driver *driver)
{
- int i,j,k,res;
+ int res = 0, i, j, k;
- DRV_LOCK();
+ down(&core_lists);
for (i = 0; i < I2C_DRIVER_MAX; i++)
if (driver == drivers[i])
break;
printk(KERN_WARNING " i2c-core.o: unregister_driver: "
"[%s] not found\n",
driver->name);
- DRV_UNLOCK();
- return -ENODEV;
+ res = -ENODEV;
+ goto out_unlock;
}
+
/* Have a look at each adapter, if clients of this driver are still
* attached. If so, detach them to be able to kill the driver
* afterwards.
*/
DEB2(printk(KERN_DEBUG "i2c-core.o: unregister_driver - looking for clients.\n"));
+
/* removing clients does not depend on the notify flag, else
* invalid operation might (will!) result, when using stale client
* pointers.
*/
- ADAP_LOCK(); /* should be moved inside the if statement... */
for (k=0;k<I2C_ADAP_MAX;k++) {
struct i2c_adapter *adap = adapters[k];
if (adap == NULL) /* skip empty entries. */
"not be detached properly; driver "
"not unloaded!",driver->name,
adap->name);
- ADAP_UNLOCK();
- return res;
+ goto out_unlock;
}
} else {
for (j=0;j<I2C_CLIENT_MAX;j++) {
driver->name,
client->addr,
adap->name);
- ADAP_UNLOCK();
- return res;
+ goto out_unlock;
}
}
}
}
}
- ADAP_UNLOCK();
drivers[i] = NULL;
- DRV_UNLOCK();
DEB(printk(KERN_DEBUG "i2c-core.o: driver unregistered: %s\n",driver->name));
+
+ out_unlock:
+ up(&core_lists);
return 0;
}
-int i2c_check_addr (struct i2c_adapter *adapter, int addr)
+static int __i2c_check_addr(struct i2c_adapter *adapter, int addr)
{
int i;
- for (i = 0; i < I2C_CLIENT_MAX ; i++)
+
+ for (i = 0; i < I2C_CLIENT_MAX ; i++)
if (adapter->clients[i] && (adapter->clients[i]->addr == addr))
return -EBUSY;
+
return 0;
}
+int i2c_check_addr(struct i2c_adapter *adapter, int addr)
+{
+ int rval;
+
+ down(&adapter->list);
+ rval = __i2c_check_addr(adapter, addr);
+ up(&adapter->list);
+
+ return rval;
+}
+
int i2c_attach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
- int i;
+ int res = -EBUSY, i;
- if (i2c_check_addr(client->adapter,client->addr))
- return -EBUSY;
+ down(&adapter->list);
+ if (__i2c_check_addr(client->adapter,client->addr))
+ goto out_unlock_list;
for (i = 0; i < I2C_CLIENT_MAX; i++)
if (NULL == adapter->clients[i])
printk(KERN_WARNING
" i2c-core.o: attach_client(%s) - enlarge I2C_CLIENT_MAX.\n",
client->name);
- return -ENOMEM;
+ res = -ENOMEM;
+ goto out_unlock_list;
}
adapter->clients[i] = client;
- adapter->client_count++;
+ up(&adapter->list);
if (adapter->client_register)
if (adapter->client_register(client))
client->usage_count = 0;
return 0;
+
+ out_unlock_list:
+ up(&adapter->list);
+ return res;
}
int i2c_detach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
- int i,res;
+ int res = 0, i;
+
+ if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
+ return -EBUSY;
- for (i = 0; i < I2C_CLIENT_MAX; i++)
+ if (adapter->client_unregister) {
+ res = adapter->client_unregister(client);
+ if (res) {
+ printk(KERN_ERR "i2c-core.o: client_unregister [%s] failed, "
+ "client not detached",client->name);
+ return res;
+ }
+ }
+
+ down(&adapter->list);
+ for (i = 0; i < I2C_CLIENT_MAX; i++) {
if (client == adapter->clients[i])
break;
+ }
+
if (I2C_CLIENT_MAX == i) {
printk(KERN_WARNING " i2c-core.o: unregister_client "
"[%s] not found\n",
client->name);
return -ENODEV;
- }
-
- if( (client->flags & I2C_CLIENT_ALLOW_USE) &&
- (client->usage_count>0))
- return -EBUSY;
-
- if (adapter->client_unregister != NULL)
- if ((res = adapter->client_unregister(client))) {
- printk(KERN_ERR "i2c-core.o: client_unregister [%s] failed, "
- "client not detached",client->name);
- return res;
- }
-
- adapter->clients[i] = NULL;
- adapter->client_count--;
+ } else
+ adapter->clients[i] = NULL;
+ up(&adapter->list);
- DEB(printk(KERN_DEBUG "i2c-core.o: client [%s] unregistered.\n",client->name));
return 0;
}
{
int i;
int nr = 0;
+
/* Note that it is safe to write a `little' beyond len. Yes, really. */
- for (i = 0; (i < I2C_ADAP_MAX) && (nr < len); i++)
+ /* Fuck you. Will convert this to seq_file later. --hch */
+
+ down(&core_lists);
+ for (i = 0; (i < I2C_ADAP_MAX) && (nr < len); i++) {
if (adapters[i]) {
nr += sprintf(buf+nr, "i2c-%d\t", i);
if (adapters[i]->algo->smbus_xfer) {
adapters[i]->name,
adapters[i]->algo->name);
}
+ }
+ up(&core_lists);
+
return nr;
}
remove_proc_entry(name, proc_bus);
}
-static int i2cproc_init(void)
+static int __init i2cproc_init(void)
{
-
struct proc_dir_entry *proc_bus_i2c;
proc_bus_i2c = create_proc_entry("i2c",0,proc_bus);
DEB2(printk(KERN_DEBUG "i2c-core.o: master_xfer: %s with %d msgs.\n",
adap->name,num));
- I2C_LOCK(adap);
+ down(&adap->bus);
ret = adap->algo->master_xfer(adap,msgs,num);
- I2C_UNLOCK(adap);
+ up(&adap->bus);
return ret;
} else {
DEB2(printk(KERN_DEBUG "i2c-core.o: master_send: writing %d bytes on %s.\n",
count,client->adapter->name));
- I2C_LOCK(adap);
+ down(&adap->bus);
ret = adap->algo->master_xfer(adap,&msg,1);
- I2C_UNLOCK(adap);
+ up(&adap->bus);
/* if everything went ok (i.e. 1 msg transmitted), return #bytes
* transmitted, else error code.
DEB2(printk(KERN_DEBUG "i2c-core.o: master_recv: reading %d bytes on %s.\n",
count,client->adapter->name));
- I2C_LOCK(adap);
+ down(&adap->bus);
ret = adap->algo->master_xfer(adap,&msg,1);
- I2C_UNLOCK(adap);
+ up(&adap->bus);
DEB2(printk(KERN_DEBUG "i2c-core.o: master_recv: return:%d (count:%d, addr:0x%02x)\n",
ret, count, client->addr));
}
if (adapter->algo->smbus_xfer) {
- I2C_LOCK(adapter);
+ down(&adapter->bus);
res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
command,size,data);
- I2C_UNLOCK(adapter);
+ up(&adapter->bus);
} else
res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
command,size,data);
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