windfarm_lm75_sensor.c
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/*
* Windfarm PowerMac thermal control. LM75 sensor
*
* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
*
* Released under the term of the GNU GPL v2.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/i2c.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "1.0"
#undef DEBUG
#ifdef DEBUG
#define DBG(args...) printk(args)
#else
#define DBG(args...) do { } while(0)
#endif
struct wf_lm75_sensor {
int ds1775 : 1;
int inited : 1;
struct i2c_client *i2c;
struct wf_sensor sens;
};
#define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens)
static int wf_lm75_get(struct wf_sensor *sr, s32 *value)
{
struct wf_lm75_sensor *lm = wf_to_lm75(sr);
s32 data;
if (lm->i2c == NULL)
return -ENODEV;
/* Init chip if necessary */
if (!lm->inited) {
u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1);
DBG("wf_lm75: Initializing %s, cfg was: %02x\n",
sr->name, cfg);
/* clear shutdown bit, keep other settings as left by
* the firmware for now
*/
cfg_new = cfg & ~0x01;
i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new);
lm->inited = 1;
/* If we just powered it up, let's wait 200 ms */
msleep(200);
}
/* Read temperature register */
data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0));
data <<= 8;
*value = data;
return 0;
}
static void wf_lm75_release(struct wf_sensor *sr)
{
struct wf_lm75_sensor *lm = wf_to_lm75(sr);
kfree(lm);
}
static struct wf_sensor_ops wf_lm75_ops = {
.get_value = wf_lm75_get,
.release = wf_lm75_release,
.owner = THIS_MODULE,
};
static int wf_lm75_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct wf_lm75_sensor *lm;
int rc, ds1775 = id->driver_data;
const char *name, *loc;
DBG("wf_lm75: creating %s device at address 0x%02x\n",
ds1775 ? "ds1775" : "lm75", client->addr);
loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
if (!loc) {
dev_warn(&client->dev, "Missing hwsensor-location property!\n");
return -ENXIO;
}
/* Usual rant about sensor names not beeing very consistent in
* the device-tree, oh well ...
* Add more entries below as you deal with more setups
*/
if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY"))
name = "hd-temp";
else if (!strcmp(loc, "Incoming Air Temp"))
name = "incoming-air-temp";
else if (!strcmp(loc, "ODD Temp"))
name = "optical-drive-temp";
else if (!strcmp(loc, "HD Temp"))
name = "hard-drive-temp";
else if (!strcmp(loc, "PCI SLOTS"))
name = "slots-temp";
else if (!strcmp(loc, "CPU A INLET"))
name = "cpu-inlet-temp-0";
else if (!strcmp(loc, "CPU B INLET"))
name = "cpu-inlet-temp-1";
else
return -ENXIO;
lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
if (lm == NULL)
return -ENODEV;
lm->inited = 0;
lm->ds1775 = ds1775;
lm->i2c = client;
lm->sens.name = name;
lm->sens.ops = &wf_lm75_ops;
i2c_set_clientdata(client, lm);
rc = wf_register_sensor(&lm->sens);
if (rc)
kfree(lm);
return rc;
}
static int wf_lm75_remove(struct i2c_client *client)
{
struct wf_lm75_sensor *lm = i2c_get_clientdata(client);
DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
/* Mark client detached */
lm->i2c = NULL;
/* release sensor */
wf_unregister_sensor(&lm->sens);
return 0;
}
static const struct i2c_device_id wf_lm75_id[] = {
{ "MAC,lm75", 0 },
{ "MAC,ds1775", 1 },
{ }
};
MODULE_DEVICE_TABLE(i2c, wf_lm75_id);
static struct i2c_driver wf_lm75_driver = {
.driver = {
.name = "wf_lm75",
},
.probe = wf_lm75_probe,
.remove = wf_lm75_remove,
.id_table = wf_lm75_id,
};
module_i2c_driver(wf_lm75_driver);
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");