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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/system.h>
#include <asm/sections.h>
#include <asm/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "0.2"
#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)
#define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c)
static int wf_lm75_attach(struct i2c_adapter *adapter);
static int wf_lm75_detach(struct i2c_client *client);
static struct i2c_driver wf_lm75_driver = {
.driver = {
.name = "wf_lm75",
},
.attach_adapter = wf_lm75_attach,
.detach_client = wf_lm75_detach,
};
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.adapter == 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);
/* check if client is registered and detach from i2c */
if (lm->i2c.adapter) {
i2c_detach_client(&lm->i2c);
lm->i2c.adapter = NULL;
}
kfree(lm);
}
static struct wf_sensor_ops wf_lm75_ops = {
.get_value = wf_lm75_get,
.release = wf_lm75_release,
.owner = THIS_MODULE,
};
static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter,
u8 addr, int ds1775,
const char *loc)
{
struct wf_lm75_sensor *lm;
int rc;
DBG("wf_lm75: creating %s device at address 0x%02x\n",
ds1775 ? "ds1775" : "lm75", addr);
lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL);
if (lm == NULL)
return NULL;
memset(lm, 0, sizeof(struct wf_lm75_sensor));
/* 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"))
lm->sens.name = "hd-temp";
else
goto fail;
lm->inited = 0;
lm->sens.ops = &wf_lm75_ops;
lm->ds1775 = ds1775;
lm->i2c.addr = (addr >> 1) & 0x7f;
lm->i2c.adapter = adapter;
lm->i2c.driver = &wf_lm75_driver;
strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1);
rc = i2c_attach_client(&lm->i2c);
if (rc) {
printk(KERN_ERR "windfarm: failed to attach %s %s to i2c,"
" err %d\n", ds1775 ? "ds1775" : "lm75",
lm->i2c.name, rc);
goto fail;
}
if (wf_register_sensor(&lm->sens)) {
i2c_detach_client(&lm->i2c);
goto fail;
}
return lm;
fail:
kfree(lm);
return NULL;
}
static int wf_lm75_attach(struct i2c_adapter *adapter)
{
struct device_node *busnode, *dev;
struct pmac_i2c_bus *bus;
DBG("wf_lm75: adapter %s detected\n", adapter->name);
bus = pmac_i2c_adapter_to_bus(adapter);
if (bus == NULL)
return -ENODEV;
busnode = pmac_i2c_get_bus_node(bus);
DBG("wf_lm75: bus found, looking for device...\n");
/* Now look for lm75(s) in there */
for (dev = NULL;
(dev = of_get_next_child(busnode, dev)) != NULL;) {
const char *loc =
of_get_property(dev, "hwsensor-location", 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;
addr = pmac_i2c_get_dev_addr(dev);
if (loc == NULL || addr == 0)
continue;
/* real lm75 */
if (of_device_is_compatible(dev, "lm75"))
wf_lm75_create(adapter, addr, 0, loc);
/* ds1775 (compatible, better resolution */
else if (of_device_is_compatible(dev, "ds1775"))
wf_lm75_create(adapter, addr, 1, loc);
}
return 0;
}
static int wf_lm75_detach(struct i2c_client *client)
{
struct wf_lm75_sensor *lm = i2c_to_lm75(client);
DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name);
/* Mark client detached */
lm->i2c.adapter = NULL;
/* release sensor */
wf_unregister_sensor(&lm->sens);
return 0;
}
static int __init wf_lm75_sensor_init(void)
{
/* Don't register on old machines that use therm_pm72 for now */
if (machine_is_compatible("PowerMac7,2") ||
machine_is_compatible("PowerMac7,3") ||
machine_is_compatible("RackMac3,1"))
return -ENODEV;
return i2c_add_driver(&wf_lm75_driver);
}
static void __exit wf_lm75_sensor_exit(void)
{
i2c_del_driver(&wf_lm75_driver);
}
module_init(wf_lm75_sensor_init);
module_exit(wf_lm75_sensor_exit);
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");
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