linux-stable/drivers/macintosh/windfarm_max6690_sensor.c
Wolfram Sang fbae3fb154 i2c: Remove all i2c_set_clientdata(client, NULL) in drivers
I2C drivers can use the clientdata-pointer to point to private data. As I2C
devices are not really unregistered, but merely detached from their driver, it
used to be the drivers obligation to clear this pointer during remove() or a
failed probe(). As a couple of drivers forgot to do this, it was agreed that it
was cleaner if the i2c-core does this clearance when appropriate, as there is
no guarantee for the lifetime of the clientdata-pointer after remove() anyhow.
This feature was added to the core with commit
e4a7b9b04d to fix the faulty drivers.

As there is no need anymore to clear the clientdata-pointer, remove all current
occurrences in the drivers to simplify the code and prevent confusion.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-06-03 11:33:58 +02:00

207 lines
4.7 KiB
C

/*
* Windfarm PowerMac thermal control. MAX6690 sensor.
*
* Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
*
* Use and redistribute under the terms of the GNU GPL v2.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <asm/prom.h>
#include <asm/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "0.2"
/* This currently only exports the external temperature sensor,
since that's all the control loops need. */
/* Some MAX6690 register numbers */
#define MAX6690_INTERNAL_TEMP 0
#define MAX6690_EXTERNAL_TEMP 1
struct wf_6690_sensor {
struct i2c_client *i2c;
struct wf_sensor sens;
};
#define wf_to_6690(x) container_of((x), struct wf_6690_sensor, sens)
static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
{
struct wf_6690_sensor *max = wf_to_6690(sr);
s32 data;
if (max->i2c == NULL)
return -ENODEV;
/* chip gets initialized by firmware */
data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP);
if (data < 0)
return data;
*value = data << 16;
return 0;
}
static void wf_max6690_release(struct wf_sensor *sr)
{
struct wf_6690_sensor *max = wf_to_6690(sr);
kfree(max);
}
static struct wf_sensor_ops wf_max6690_ops = {
.get_value = wf_max6690_get,
.release = wf_max6690_release,
.owner = THIS_MODULE,
};
static int wf_max6690_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct wf_6690_sensor *max;
int rc;
max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
if (max == NULL) {
printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor: "
"no memory\n");
return -ENOMEM;
}
max->i2c = client;
max->sens.name = client->dev.platform_data;
max->sens.ops = &wf_max6690_ops;
i2c_set_clientdata(client, max);
rc = wf_register_sensor(&max->sens);
if (rc) {
kfree(max);
}
return rc;
}
static struct i2c_driver wf_max6690_driver;
static struct i2c_client *wf_max6690_create(struct i2c_adapter *adapter,
u8 addr, const char *loc)
{
struct i2c_board_info info;
struct i2c_client *client;
char *name;
if (!strcmp(loc, "BACKSIDE"))
name = "backside-temp";
else if (!strcmp(loc, "NB Ambient"))
name = "north-bridge-temp";
else if (!strcmp(loc, "GPU Ambient"))
name = "gpu-temp";
else
goto fail;
memset(&info, 0, sizeof(struct i2c_board_info));
info.addr = addr >> 1;
info.platform_data = name;
strlcpy(info.type, "wf_max6690", I2C_NAME_SIZE);
client = i2c_new_device(adapter, &info);
if (client == NULL) {
printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
goto fail;
}
/*
* Let i2c-core delete that device on driver removal.
* This is safe because i2c-core holds the core_lock mutex for us.
*/
list_add_tail(&client->detected, &wf_max6690_driver.clients);
return client;
fail:
return NULL;
}
static int wf_max6690_attach(struct i2c_adapter *adapter)
{
struct device_node *busnode, *dev = NULL;
struct pmac_i2c_bus *bus;
const char *loc;
bus = pmac_i2c_adapter_to_bus(adapter);
if (bus == NULL)
return -ENODEV;
busnode = pmac_i2c_get_bus_node(bus);
while ((dev = of_get_next_child(busnode, dev)) != NULL) {
u8 addr;
/* We must re-match the adapter in order to properly check
* the channel on multibus setups
*/
if (!pmac_i2c_match_adapter(dev, adapter))
continue;
if (!of_device_is_compatible(dev, "max6690"))
continue;
addr = pmac_i2c_get_dev_addr(dev);
loc = of_get_property(dev, "hwsensor-location", NULL);
if (loc == NULL || addr == 0)
continue;
printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
wf_max6690_create(adapter, addr, loc);
}
return 0;
}
static int wf_max6690_remove(struct i2c_client *client)
{
struct wf_6690_sensor *max = i2c_get_clientdata(client);
max->i2c = NULL;
wf_unregister_sensor(&max->sens);
return 0;
}
static const struct i2c_device_id wf_max6690_id[] = {
{ "wf_max6690", 0 },
{ }
};
static struct i2c_driver wf_max6690_driver = {
.driver = {
.name = "wf_max6690",
},
.attach_adapter = wf_max6690_attach,
.probe = wf_max6690_probe,
.remove = wf_max6690_remove,
.id_table = wf_max6690_id,
};
static int __init wf_max6690_sensor_init(void)
{
/* Don't register on old machines that use therm_pm72 for now */
if (of_machine_is_compatible("PowerMac7,2") ||
of_machine_is_compatible("PowerMac7,3") ||
of_machine_is_compatible("RackMac3,1"))
return -ENODEV;
return i2c_add_driver(&wf_max6690_driver);
}
static void __exit wf_max6690_sensor_exit(void)
{
i2c_del_driver(&wf_max6690_driver);
}
module_init(wf_max6690_sensor_init);
module_exit(wf_max6690_sensor_exit);
MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
MODULE_LICENSE("GPL");