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// SPDX-License-Identifier: GPL-2.0-only
/*
* Windfarm PowerMac thermal control. MAX6690 sensor.
*
* Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
*/
#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/pmac_low_i2c.h>
#include "windfarm.h"
#define VERSION "1.0"
/* 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 const 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 char *name, *loc;
struct wf_6690_sensor *max;
int rc;
loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
if (!loc) {
dev_warn(&client->dev, "Missing hwsensor-location property!\n");
return -ENXIO;
}
/*
* We only expose the external temperature register for
* now as this is all we need for our control loops
*/
if (!strcmp(loc, "BACKSIDE") || !strcmp(loc, "SYS CTRLR AMBIENT"))
name = "backside-temp";
else if (!strcmp(loc, "NB Ambient"))
name = "north-bridge-temp";
else if (!strcmp(loc, "GPU Ambient"))
name = "gpu-temp";
else
return -ENXIO;
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 = name;
max->sens.ops = &wf_max6690_ops;
i2c_set_clientdata(client, max);
rc = wf_register_sensor(&max->sens);
if (rc)
kfree(max);
return rc;
}
static void wf_max6690_remove(struct i2c_client *client)
{
struct wf_6690_sensor *max = i2c_get_clientdata(client);
max->i2c = NULL;
wf_unregister_sensor(&max->sens);
}
static const struct i2c_device_id wf_max6690_id[] = {
{ "MAC,max6690" },
{ }
};
MODULE_DEVICE_TABLE(i2c, wf_max6690_id);
static const struct of_device_id wf_max6690_of_id[] = {
{ .compatible = "max6690", },
{ }
};
MODULE_DEVICE_TABLE(of, wf_max6690_of_id);
static struct i2c_driver wf_max6690_driver = {
.driver = {
.name = "wf_max6690",
.of_match_table = wf_max6690_of_id,
},
.probe = wf_max6690_probe,
.remove = wf_max6690_remove,
.id_table = wf_max6690_id,
};
module_i2c_driver(wf_max6690_driver);
MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
MODULE_LICENSE("GPL");
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