renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-18 10:13:57 +08:00
Code
b3d5496ea5
linux-next/drivers/i2c/i2c-core.c
Jean Delvare b3d5496ea5 [PATCH] I2C: Kill address ranges in non-sensors i2c chip drivers 
Some months ago, you killed the address ranges mechanism from all
sensors i2c chip drivers (both the module parameters and the in-code
address lists). I think it was a very good move, as the ranges can
easily be replaced by individual addresses, and this allowed for
significant cleanups in the i2c core (let alone the impressive size
shrink for all these drivers).

Unfortunately you did not do the same for non-sensors i2c chip drivers.
These need the address ranges even less, so we could get rid of the
ranges here as well for another significant i2c core cleanup. Here comes
a patch which does just that. Since the process is exactly the same as
what you did for the other drivers set already, I did not split this one
in parts.

A documentation update is included.

The change saves 308 bytes in the i2c core, and an average 1382 bytes
for chip drivers which use I2C_CLIENT_INSMOD, 126 bytes for those which
do not.

This change is required if we want to merge the sensors and non-sensors
i2c code (and we want to do this).

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Index: gregkh-2.6/Documentation/i2c/writing-clients
===================================================================
2005-06-21 21:51:48 -07:00

1238 lines
32 KiB
C
Raw Blame History

/* i2c-core.c - a device driver for the iic-bus interface */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 1995-99 Simon G. Vogl
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/idr.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
static LIST_HEAD(adapters);
static LIST_HEAD(drivers);
static DECLARE_MUTEX(core_lists);
static DEFINE_IDR(i2c_adapter_idr);
/* match always succeeds, as we want the probe() to tell if we really accept this match */
static int i2c_device_match(struct device *dev, struct device_driver *drv)
{
return 1;
}
static int i2c_bus_suspend(struct device * dev, pm_message_t state)
{
int rc = 0;
if (dev->driver && dev->driver->suspend)
rc = dev->driver->suspend(dev,state,0);
return rc;
}
static int i2c_bus_resume(struct device * dev)
{
int rc = 0;
if (dev->driver && dev->driver->resume)
rc = dev->driver->resume(dev,0);
return rc;
}
static struct bus_type i2c_bus_type = {
.name = "i2c",
.match = i2c_device_match,
.suspend = i2c_bus_suspend,
.resume = i2c_bus_resume,
};
static int i2c_device_probe(struct device *dev)
{
return -ENODEV;
}
static int i2c_device_remove(struct device *dev)
{
return 0;
}
static void i2c_adapter_dev_release(struct device *dev)
{
struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
complete(&adap->dev_released);
}
static struct device_driver i2c_adapter_driver = {
.name = "i2c_adapter",
.bus = &i2c_bus_type,
.probe = i2c_device_probe,
.remove = i2c_device_remove,
};
static void i2c_adapter_class_dev_release(struct class_device *dev)
{
struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
complete(&adap->class_dev_released);
}
static struct class i2c_adapter_class = {
.name = "i2c-adapter",
.release = &i2c_adapter_class_dev_release,
};
static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
{
struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
return sprintf(buf, "%s\n", adap->name);
}
static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
static void i2c_client_release(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
complete(&client->released);
}
static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%s\n", client->name);
}
/*
* We can't use the DEVICE_ATTR() macro here as we want the same filename for a
* different type of a device. So beware if the DEVICE_ATTR() macro ever
* changes, this definition will also have to change.
*/
static struct device_attribute dev_attr_client_name = {
.attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
.show = &show_client_name,
};
/* ---------------------------------------------------
* registering functions
* ---------------------------------------------------
*/
/* -----
* i2c_add_adapter is called from within the algorithm layer,
* when a new hw adapter registers. A new device is register to be
* available for clients.
*/
int i2c_add_adapter(struct i2c_adapter *adap)
{
int id, res = 0;
struct list_head *item;
struct i2c_driver *driver;
down(&core_lists);
if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
res = -ENOMEM;
goto out_unlock;
}
res = idr_get_new(&i2c_adapter_idr, NULL, &id);
if (res < 0) {
if (res == -EAGAIN)
res = -ENOMEM;
goto out_unlock;
}
adap->nr = id & MAX_ID_MASK;
init_MUTEX(&adap->bus_lock);
init_MUTEX(&adap->clist_lock);
list_add_tail(&adap->list,&adapters);
INIT_LIST_HEAD(&adap->clients);
/* Add the adapter to the driver core.
* If the parent pointer is not set up,
* we add this adapter to the host bus.
*/
if (adap->dev.parent == NULL)
adap->dev.parent = &platform_bus;
sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
adap->dev.driver = &i2c_adapter_driver;
adap->dev.release = &i2c_adapter_dev_release;
device_register(&adap->dev);
device_create_file(&adap->dev, &dev_attr_name);
/* Add this adapter to the i2c_adapter class */
memset(&adap->class_dev, 0x00, sizeof(struct class_device));
adap->class_dev.dev = &adap->dev;
adap->class_dev.class = &i2c_adapter_class;
strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
class_device_register(&adap->class_dev);
/* inform drivers of new adapters */
list_for_each(item,&drivers) {
driver = list_entry(item, struct i2c_driver, list);
if (driver->flags & I2C_DF_NOTIFY)
/* We ignore the return code; if it fails, too bad */
driver->attach_adapter(adap);
}
dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr);
out_unlock:
up(&core_lists);
return res;
}
int i2c_del_adapter(struct i2c_adapter *adap)
{
struct list_head *item, *_n;
struct i2c_adapter *adap_from_list;
struct i2c_driver *driver;
struct i2c_client *client;
int res = 0;
down(&core_lists);
/* First make sure that this adapter was ever added */
list_for_each_entry(adap_from_list, &adapters, list) {
if (adap_from_list == adap)
break;
}
if (adap_from_list != adap) {
pr_debug("I2C: Attempting to delete an unregistered "
"adapter\n");
res = -EINVAL;
goto out_unlock;
}
list_for_each(item,&drivers) {
driver = list_entry(item, struct i2c_driver, list);
if (driver->detach_adapter)
if ((res = driver->detach_adapter(adap))) {
dev_warn(&adap->dev, "can't detach adapter "
"while detaching driver %s: driver not "
"detached!", driver->name);
goto out_unlock;
}
}
/* detach any active clients. This must be done first, because
* it can fail; in which case we give upp. */
list_for_each_safe(item, _n, &adap->clients) {
client = list_entry(item, struct i2c_client, list);
/* 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.
*/
if ((res=client->driver->detach_client(client))) {
dev_err(&adap->dev, "adapter not "
"unregistered, because client at "
"address %02x can't be detached. ",
client->addr);
goto out_unlock;
}
}
/* clean up the sysfs representation */
init_completion(&adap->dev_released);
init_completion(&adap->class_dev_released);
class_device_unregister(&adap->class_dev);
device_remove_file(&adap->dev, &dev_attr_name);
device_unregister(&adap->dev);
list_del(&adap->list);
/* wait for sysfs to drop all references */
wait_for_completion(&adap->dev_released);
wait_for_completion(&adap->class_dev_released);
/* free dynamically allocated bus id */
idr_remove(&i2c_adapter_idr, adap->nr);
dev_dbg(&adap->dev, "adapter unregistered\n");
out_unlock:
up(&core_lists);
return res;
}
/* -----
* What follows is the "upwards" interface: commands for talking to clients,
* which implement the functions to access the physical information of the
* chips.
*/
int i2c_add_driver(struct i2c_driver *driver)
{
struct list_head *item;
struct i2c_adapter *adapter;
int res = 0;
down(&core_lists);
/* add the driver to the list of i2c drivers in the driver core */
driver->driver.name = driver->name;
driver->driver.bus = &i2c_bus_type;
driver->driver.probe = i2c_device_probe;
driver->driver.remove = i2c_device_remove;
res = driver_register(&driver->driver);
if (res)
goto out_unlock;
list_add_tail(&driver->list,&drivers);
pr_debug("i2c-core: driver %s registered.\n", driver->name);
/* now look for instances of driver on our adapters */
if (driver->flags & I2C_DF_NOTIFY) {
list_for_each(item,&adapters) {
adapter = list_entry(item, struct i2c_adapter, list);
driver->attach_adapter(adapter);
}
}
out_unlock:
up(&core_lists);
return res;
}
int i2c_del_driver(struct i2c_driver *driver)
{
struct list_head *item1, *item2, *_n;
struct i2c_client *client;
struct i2c_adapter *adap;
int res = 0;
down(&core_lists);
/* 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.
*/
pr_debug("i2c-core: 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.
*/
list_for_each(item1,&adapters) {
adap = list_entry(item1, struct i2c_adapter, list);
dev_dbg(&adap->dev, "examining adapter\n");
if (driver->detach_adapter) {
if ((res = driver->detach_adapter(adap))) {
dev_warn(&adap->dev, "while unregistering "
"dummy driver %s, adapter could "
"not be detached properly; driver "
"not unloaded!",driver->name);
goto out_unlock;
}
} else {
list_for_each_safe(item2, _n, &adap->clients) {
client = list_entry(item2, struct i2c_client, list);
if (client->driver != driver)
continue;
pr_debug("i2c-core.o: detaching client %s:\n", client->name);
if ((res = driver->detach_client(client))) {
dev_err(&adap->dev, "while "
"unregistering driver "
"`%s', the client at "
"address %02x of "
"adapter could not "
"be detached; driver "
"not unloaded!",
driver->name,
client->addr);
goto out_unlock;
}
}
}
}
driver_unregister(&driver->driver);
list_del(&driver->list);
pr_debug("i2c-core: driver unregistered: %s\n", driver->name);
out_unlock:
up(&core_lists);
return 0;
}
static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
struct list_head *item;
struct i2c_client *client;
list_for_each(item,&adapter->clients) {
client = list_entry(item, struct i2c_client, list);
if (client->addr == addr)
return -EBUSY;
}
return 0;
}
int i2c_check_addr(struct i2c_adapter *adapter, int addr)
{
int rval;
down(&adapter->clist_lock);
rval = __i2c_check_addr(adapter, addr);
up(&adapter->clist_lock);
return rval;
}
int i2c_attach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
down(&adapter->clist_lock);
if (__i2c_check_addr(client->adapter, client->addr)) {
up(&adapter->clist_lock);
return -EBUSY;
}
list_add_tail(&client->list,&adapter->clients);
up(&adapter->clist_lock);
if (adapter->client_register) {
if (adapter->client_register(client)) {
dev_warn(&adapter->dev, "warning: client_register "
"seems to have failed for client %02x\n",
client->addr);
}
}
dev_dbg(&adapter->dev, "client [%s] registered to adapter\n",
client->name);
if (client->flags & I2C_CLIENT_ALLOW_USE)
client->usage_count = 0;
client->dev.parent = &client->adapter->dev;
client->dev.driver = &client->driver->driver;
client->dev.bus = &i2c_bus_type;
client->dev.release = &i2c_client_release;
snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
"%d-%04x", i2c_adapter_id(adapter), client->addr);
pr_debug("registering %s\n", client->dev.bus_id);
device_register(&client->dev);
device_create_file(&client->dev, &dev_attr_client_name);
return 0;
}
int i2c_detach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
int res = 0;
if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0))
return -EBUSY;
if (adapter->client_unregister) {
res = adapter->client_unregister(client);
if (res) {
dev_err(&client->dev,
"client_unregister [%s] failed, "
"client not detached", client->name);
goto out;
}
}
down(&adapter->clist_lock);
list_del(&client->list);
init_completion(&client->released);
device_remove_file(&client->dev, &dev_attr_client_name);
device_unregister(&client->dev);
up(&adapter->clist_lock);
wait_for_completion(&client->released);
out:
return res;
}
static int i2c_inc_use_client(struct i2c_client *client)
{
if (!try_module_get(client->driver->owner))
return -ENODEV;
if (!try_module_get(client->adapter->owner)) {
module_put(client->driver->owner);
return -ENODEV;
}
return 0;
}
static void i2c_dec_use_client(struct i2c_client *client)
{
module_put(client->driver->owner);
module_put(client->adapter->owner);
}
int i2c_use_client(struct i2c_client *client)
{
int ret;
ret = i2c_inc_use_client(client);
if (ret)
return ret;
if (client->flags & I2C_CLIENT_ALLOW_USE) {
if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE)
client->usage_count++;
else if (client->usage_count > 0)
goto busy;
else
client->usage_count++;
}
return 0;
busy:
i2c_dec_use_client(client);
return -EBUSY;
}
int i2c_release_client(struct i2c_client *client)
{
if(client->flags & I2C_CLIENT_ALLOW_USE) {
if(client->usage_count>0)
client->usage_count--;
else {
pr_debug("i2c-core: %s used one too many times\n",
__FUNCTION__);
return -EPERM;
}
}
i2c_dec_use_client(client);
return 0;
}
void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
{
struct list_head *item;
struct i2c_client *client;
down(&adap->clist_lock);
list_for_each(item,&adap->clients) {
client = list_entry(item, struct i2c_client, list);
if (!try_module_get(client->driver->owner))
continue;
if (NULL != client->driver->command) {
up(&adap->clist_lock);
client->driver->command(client,cmd,arg);
down(&adap->clist_lock);
}
module_put(client->driver->owner);
}
up(&adap->clist_lock);
}
static int __init i2c_init(void)
{
int retval;
retval = bus_register(&i2c_bus_type);
if (retval)
return retval;
retval = driver_register(&i2c_adapter_driver);
if (retval)
return retval;
return class_register(&i2c_adapter_class);
}
static void __exit i2c_exit(void)
{
class_unregister(&i2c_adapter_class);
driver_unregister(&i2c_adapter_driver);
bus_unregister(&i2c_bus_type);
}
subsys_initcall(i2c_init);
module_exit(i2c_exit);
/* ----------------------------------------------------
* the functional interface to the i2c busses.
* ----------------------------------------------------
*/
int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
{
int ret;
if (adap->algo->master_xfer) {
#ifdef DEBUG
for (ret = 0; ret < num; ret++) {
dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
"len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
'R' : 'W', msgs[ret].addr, msgs[ret].len);
}
#endif
down(&adap->bus_lock);
ret = adap->algo->master_xfer(adap,msgs,num);
up(&adap->bus_lock);
return ret;
} else {
dev_dbg(&adap->dev, "I2C level transfers not supported\n");
return -ENOSYS;
}
}
int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
{
int ret;
struct i2c_adapter *adap=client->adapter;
struct i2c_msg msg;
if (client->adapter->algo->master_xfer) {
msg.addr = client->addr;
msg.flags = client->flags & I2C_M_TEN;
msg.len = count;
msg.buf = (char *)buf;
dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n",
count);
down(&adap->bus_lock);
ret = adap->algo->master_xfer(adap,&msg,1);
up(&adap->bus_lock);
/* if everything went ok (i.e. 1 msg transmitted), return #bytes
* transmitted, else error code.
*/
return (ret == 1 )? count : ret;
} else {
dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
return -ENOSYS;
}
}
int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
{
struct i2c_adapter *adap=client->adapter;
struct i2c_msg msg;
int ret;
if (client->adapter->algo->master_xfer) {
msg.addr = client->addr;
msg.flags = client->flags & I2C_M_TEN;
msg.flags |= I2C_M_RD;
msg.len = count;
msg.buf = buf;
dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n",
count);
down(&adap->bus_lock);
ret = adap->algo->master_xfer(adap,&msg,1);
up(&adap->bus_lock);
dev_dbg(&client->adapter->dev, "master_recv: return:%d (count:%d, addr:0x%02x)\n",
ret, count, client->addr);
/* if everything went ok (i.e. 1 msg transmitted), return #bytes
* transmitted, else error code.
*/
return (ret == 1 )? count : ret;
} else {
dev_err(&client->adapter->dev, "I2C level transfers not supported\n");
return -ENOSYS;
}
}
int i2c_control(struct i2c_client *client,
unsigned int cmd, unsigned long arg)
{
int ret = 0;
struct i2c_adapter *adap = client->adapter;
dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
switch (cmd) {
case I2C_RETRIES:
adap->retries = arg;
break;
case I2C_TIMEOUT:
adap->timeout = arg;
break;
default:
if (adap->algo->algo_control!=NULL)
ret = adap->algo->algo_control(adap,cmd,arg);
}
return ret;
}
/* ----------------------------------------------------
* the i2c address scanning function
* Will not work for 10-bit addresses!
* ----------------------------------------------------
*/
int i2c_probe(struct i2c_adapter *adapter,
struct i2c_client_address_data *address_data,
int (*found_proc) (struct i2c_adapter *, int, int))
{
int addr,i,found,err;
int adap_id = i2c_adapter_id(adapter);
/* Forget it if we can't probe using SMBUS_QUICK */
if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK))
return -1;
for (addr = 0x00; addr <= 0x7f; addr++) {
/* Skip if already in use */
if (i2c_check_addr(adapter,addr))
continue;
/* If it is in one of the force entries, we don't do any detection
at all */
found = 0;
for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 2) {
if (((adap_id == address_data->force[i]) ||
(address_data->force[i] == ANY_I2C_BUS)) &&
(addr == address_data->force[i+1])) {
dev_dbg(&adapter->dev, "found force parameter for adapter %d, addr %04x\n",
adap_id, addr);
if ((err = found_proc(adapter,addr,0)))
return err;
found = 1;
}
}
if (found)
continue;
/* If this address is in one of the ignores, we can forget about
it right now */
for (i = 0;
!found && (address_data->ignore[i] != I2C_CLIENT_END);
i += 2) {
if (((adap_id == address_data->ignore[i]) ||
((address_data->ignore[i] == ANY_I2C_BUS))) &&
(addr == address_data->ignore[i+1])) {
dev_dbg(&adapter->dev, "found ignore parameter for adapter %d, "
"addr %04x\n", adap_id ,addr);
found = 1;
}
}
if (found)
continue;
/* Now, we will do a detection, but only if it is in the normal or
probe entries */
for (i = 0;
!found && (address_data->normal_i2c[i] != I2C_CLIENT_END);
i += 1) {
if (addr == address_data->normal_i2c[i]) {
found = 1;
dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, "
"addr %02x\n", adap_id, addr);
}
}
for (i = 0;
!found && (address_data->probe[i] != I2C_CLIENT_END);
i += 2) {
if (((adap_id == address_data->probe[i]) ||
((address_data->probe[i] == ANY_I2C_BUS))) &&
(addr == address_data->probe[i+1])) {
found = 1;
dev_dbg(&adapter->dev, "found probe parameter for adapter %d, "
"addr %04x\n", adap_id,addr);
}
}
if (!found)
continue;
/* OK, so we really should examine this address. First check
whether there is some client here at all! */
if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
if ((err = found_proc(adapter,addr,-1)))
return err;
}
return 0;
}
/*
* return id number for a specific adapter
*/
int i2c_adapter_id(struct i2c_adapter *adap)
{
return adap->nr;
}
struct i2c_adapter* i2c_get_adapter(int id)
{
struct list_head *item;
struct i2c_adapter *adapter;
down(&core_lists);
list_for_each(item,&adapters) {
adapter = list_entry(item, struct i2c_adapter, list);
if (id == adapter->nr &&
try_module_get(adapter->owner)) {
up(&core_lists);
return adapter;
}
}
up(&core_lists);
return NULL;
}
void i2c_put_adapter(struct i2c_adapter *adap)
{
module_put(adap->owner);
}
/* The SMBus parts */
#define POLY (0x1070U << 3)
static u8
crc8(u16 data)
{
int i;
for(i = 0; i < 8; i++) {
if (data & 0x8000)
data = data ^ POLY;
data = data << 1;
}
return (u8)(data >> 8);
}
/* CRC over count bytes in the first array plus the bytes in the rest
array if it is non-null. rest[0] is the (length of rest) - 1
and is included. */
static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest)
{
int i;
for(i = 0; i < count; i++)
crc = crc8((crc ^ first[i]) << 8);
if(rest != NULL)
for(i = 0; i <= rest[0]; i++)
crc = crc8((crc ^ rest[i]) << 8);
return crc;
}
static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest)
{
return i2c_smbus_partial_pec(0, count, first, rest);
}
/* Returns new "size" (transaction type)
Note that we convert byte to byte_data and byte_data to word_data
rather than invent new xxx_PEC transactions. */
static int i2c_smbus_add_pec(u16 addr, u8 command, int size,
union i2c_smbus_data *data)
{
u8 buf[3];
buf[0] = addr << 1;
buf[1] = command;
switch(size) {
case I2C_SMBUS_BYTE:
data->byte = i2c_smbus_pec(2, buf, NULL);
size = I2C_SMBUS_BYTE_DATA;
break;
case I2C_SMBUS_BYTE_DATA:
buf[2] = data->byte;
data->word = buf[2] ||
(i2c_smbus_pec(3, buf, NULL) << 8);
size = I2C_SMBUS_WORD_DATA;
break;
case I2C_SMBUS_WORD_DATA:
/* unsupported */
break;
case I2C_SMBUS_BLOCK_DATA:
data->block[data->block[0] + 1] =
i2c_smbus_pec(2, buf, data->block);
size = I2C_SMBUS_BLOCK_DATA_PEC;
break;
}
return size;
}
static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial,
union i2c_smbus_data *data)
{
u8 buf[3], rpec, cpec;
buf[1] = command;
switch(size) {
case I2C_SMBUS_BYTE_DATA:
buf[0] = (addr << 1) | 1;
cpec = i2c_smbus_pec(2, buf, NULL);
rpec = data->byte;
break;
case I2C_SMBUS_WORD_DATA:
buf[0] = (addr << 1) | 1;
buf[2] = data->word & 0xff;
cpec = i2c_smbus_pec(3, buf, NULL);
rpec = data->word >> 8;
break;
case I2C_SMBUS_WORD_DATA_PEC:
/* unsupported */
cpec = rpec = 0;
break;
case I2C_SMBUS_PROC_CALL_PEC:
/* unsupported */
cpec = rpec = 0;
break;
case I2C_SMBUS_BLOCK_DATA_PEC:
buf[0] = (addr << 1);
buf[2] = (addr << 1) | 1;
cpec = i2c_smbus_pec(3, buf, data->block);
rpec = data->block[data->block[0] + 1];
break;
case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
buf[0] = (addr << 1) | 1;
rpec = i2c_smbus_partial_pec(partial, 1,
buf, data->block);
cpec = data->block[data->block[0] + 1];
break;
default:
cpec = rpec = 0;
break;
}
if (rpec != cpec) {
pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
rpec, cpec);
return -1;
}
return 0;
}
s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
{
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
value,0,I2C_SMBUS_QUICK,NULL);
}
s32 i2c_smbus_read_byte(struct i2c_client *client)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
return -1;
else
return 0x0FF & data.byte;
}
s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
{
union i2c_smbus_data data; /* only for PEC */
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data);
}
s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
return -1;
else
return 0x0FF & data.byte;
}
s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
{
union i2c_smbus_data data;
data.byte = value;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BYTE_DATA,&data);
}
s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
return -1;
else
return 0x0FFFF & data.word;
}
s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
{
union i2c_smbus_data data;
data.word = value;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_WORD_DATA,&data);
}
s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
u8 length, u8 *values)
{
union i2c_smbus_data data;
int i;
if (length > I2C_SMBUS_BLOCK_MAX)
length = I2C_SMBUS_BLOCK_MAX;
for (i = 1; i <= length; i++)
data.block[i] = values[i-1];
data.block[0] = length;
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BLOCK_DATA,&data);
}
/* Returns the number of read bytes */
s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
{
union i2c_smbus_data data;
int i;
if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_READ,command,
I2C_SMBUS_I2C_BLOCK_DATA,&data))
return -1;
else {
for (i = 1; i <= data.block[0]; i++)
values[i-1] = data.block[i];
return data.block[0];
}
}
/* Simulate a SMBus command using the i2c protocol
No checking of parameters is done! */
static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
/* So we need to generate a series of msgs. In the case of writing, we
need to use only one message; when reading, we need two. We initialize
most things with sane defaults, to keep the code below somewhat
simpler. */
unsigned char msgbuf0[34];
unsigned char msgbuf1[34];
int num = read_write == I2C_SMBUS_READ?2:1;
struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
{ addr, flags | I2C_M_RD, 0, msgbuf1 }
};
int i;
msgbuf0[0] = command;
switch(size) {
case I2C_SMBUS_QUICK:
msg[0].len = 0;
/* Special case: The read/write field is used as data */
msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
num = 1;
break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_READ) {
/* Special case: only a read! */
msg[0].flags = I2C_M_RD | flags;
num = 1;
}
break;
case I2C_SMBUS_BYTE_DATA:
if (read_write == I2C_SMBUS_READ)
msg[1].len = 1;
else {
msg[0].len = 2;
msgbuf0[1] = data->byte;
}
break;
case I2C_SMBUS_WORD_DATA:
if (read_write == I2C_SMBUS_READ)
msg[1].len = 2;
else {
msg[0].len=3;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
}
break;
case I2C_SMBUS_PROC_CALL:
num = 2; /* Special case */
read_write = I2C_SMBUS_READ;
msg[0].len = 3;
msg[1].len = 2;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_DATA_PEC:
if (read_write == I2C_SMBUS_READ) {
dev_err(&adapter->dev, "Block read not supported "
"under I2C emulation!\n");
return -1;
} else {
msg[0].len = data->block[0] + 2;
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
dev_err(&adapter->dev, "smbus_access called with "
"invalid block write size (%d)\n",
data->block[0]);
return -1;
}
if(size == I2C_SMBUS_BLOCK_DATA_PEC)
(msg[0].len)++;
for (i = 1; i <= msg[0].len; i++)
msgbuf0[i] = data->block[i-1];
}
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
case I2C_SMBUS_BLOCK_PROC_CALL_PEC:
dev_dbg(&adapter->dev, "Block process call not supported "
"under I2C emulation!\n");
return -1;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
} else {
msg[0].len = data->block[0] + 1;
if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
"invalid block write size (%d)\n",
data->block[0]);
return -1;
}
for (i = 1; i <= data->block[0]; i++)
msgbuf0[i] = data->block[i];
}
break;
default:
dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
size);
return -1;
}
if (i2c_transfer(adapter, msg, num) < 0)
return -1;
if (read_write == I2C_SMBUS_READ)
switch(size) {
case I2C_SMBUS_BYTE:
data->byte = msgbuf0[0];
break;
case I2C_SMBUS_BYTE_DATA:
data->byte = msgbuf1[0];
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
data->word = msgbuf1[0] | (msgbuf1[1] << 8);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
/* fixed at 32 for now */
data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX;
for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++)
data->block[i+1] = msgbuf1[i];
break;
}
return 0;
}
s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
s32 res;
int swpec = 0;
u8 partial = 0;
flags &= I2C_M_TEN | I2C_CLIENT_PEC;
if((flags & I2C_CLIENT_PEC) &&
!(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) {
swpec = 1;
if(read_write == I2C_SMBUS_READ &&
size == I2C_SMBUS_BLOCK_DATA)
size = I2C_SMBUS_BLOCK_DATA_PEC;
else if(size == I2C_SMBUS_PROC_CALL)
size = I2C_SMBUS_PROC_CALL_PEC;
else if(size == I2C_SMBUS_BLOCK_PROC_CALL) {
i2c_smbus_add_pec(addr, command,
I2C_SMBUS_BLOCK_DATA, data);
partial = data->block[data->block[0] + 1];
size = I2C_SMBUS_BLOCK_PROC_CALL_PEC;
} else if(read_write == I2C_SMBUS_WRITE &&
size != I2C_SMBUS_QUICK &&
size != I2C_SMBUS_I2C_BLOCK_DATA)
size = i2c_smbus_add_pec(addr, command, size, data);
}
if (adapter->algo->smbus_xfer) {
down(&adapter->bus_lock);
res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
command,size,data);
up(&adapter->bus_lock);
} else
res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
command,size,data);
if(res >= 0 && swpec &&
size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA &&
(read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC ||
size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) {
if(i2c_smbus_check_pec(addr, command, size, partial, data))
return -1;
}
return res;
}
EXPORT_SYMBOL(i2c_add_adapter);
EXPORT_SYMBOL(i2c_del_adapter);
EXPORT_SYMBOL(i2c_add_driver);
EXPORT_SYMBOL(i2c_del_driver);
EXPORT_SYMBOL(i2c_attach_client);
EXPORT_SYMBOL(i2c_detach_client);
EXPORT_SYMBOL(i2c_use_client);
EXPORT_SYMBOL(i2c_release_client);
EXPORT_SYMBOL(i2c_clients_command);
EXPORT_SYMBOL(i2c_check_addr);
EXPORT_SYMBOL(i2c_master_send);
EXPORT_SYMBOL(i2c_master_recv);
EXPORT_SYMBOL(i2c_control);
EXPORT_SYMBOL(i2c_transfer);
EXPORT_SYMBOL(i2c_adapter_id);
EXPORT_SYMBOL(i2c_get_adapter);
EXPORT_SYMBOL(i2c_put_adapter);
EXPORT_SYMBOL(i2c_probe);
EXPORT_SYMBOL(i2c_smbus_xfer);
EXPORT_SYMBOL(i2c_smbus_write_quick);
EXPORT_SYMBOL(i2c_smbus_read_byte);
EXPORT_SYMBOL(i2c_smbus_write_byte);
EXPORT_SYMBOL(i2c_smbus_read_byte_data);
EXPORT_SYMBOL(i2c_smbus_write_byte_data);
EXPORT_SYMBOL(i2c_smbus_read_word_data);
EXPORT_SYMBOL(i2c_smbus_write_word_data);
EXPORT_SYMBOL(i2c_smbus_write_block_data);
EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus main module");
MODULE_LICENSE("GPL");
View Git Blame Copy Permalink