/*
* 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)
#define i2c_to_6690(x) container_of((x), struct wf_6690_sensor, i2c)
static int wf_max6690_attach(struct i2c_adapter *adapter);
static int wf_max6690_detach(struct i2c_client *client);
static struct i2c_driver wf_max6690_driver = {
.driver = {
.name = "wf_max6690",
},
.attach_adapter = wf_max6690_attach,
.detach_client = wf_max6690_detach,
};
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.adapter == 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);
if (max->i2c.adapter) {
i2c_detach_client(&max->i2c);
max->i2c.adapter = NULL;
}
kfree(max);
}
static struct wf_sensor_ops wf_max6690_ops = {
.get_value = wf_max6690_get,
.release = wf_max6690_release,
.owner = THIS_MODULE,
};
static void wf_max6690_create(struct i2c_adapter *adapter, u8 addr)
{
struct wf_6690_sensor *max;
char *name = "backside-temp";
max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
if (max == NULL) {
printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor %s: "
"no memory\n", name);
return;
}
max->sens.ops = &wf_max6690_ops;
max->sens.name = name;
max->i2c.addr = addr >> 1;
max->i2c.adapter = adapter;
max->i2c.driver = &wf_max6690_driver;
strncpy(max->i2c.name, name, I2C_NAME_SIZE-1);
if (i2c_attach_client(&max->i2c)) {
printk(KERN_ERR "windfarm: failed to attach MAX6690 sensor\n");
goto fail;
}
if (wf_register_sensor(&max->sens)) {
i2c_detach_client(&max->i2c);
goto fail;
}
return;
fail:
kfree(max);
}
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 (!device_is_compatible(dev, "max6690"))
continue;
addr = pmac_i2c_get_dev_addr(dev);
loc = get_property(dev, "hwsensor-location", NULL);
if (loc == NULL || addr == 0)
continue;
printk("found max6690, loc=%s addr=0x%02x\n", loc, addr);
if (strcmp(loc, "BACKSIDE"))
continue;
wf_max6690_create(adapter, addr);
}
return 0;
}
static int wf_max6690_detach(struct i2c_client *client)
{
struct wf_6690_sensor *max = i2c_to_6690(client);
max->i2c.adapter = NULL;
wf_unregister_sensor(&max->sens);
return 0;
}
static int __init wf_max6690_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_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");
