// SPDX-License-Identifier: GPL-2.0-only
/*
* Device driver for the i2c thermostat found on the iBook G4, Albook G4
*
* Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
*
* Documentation from 115254175ADT7467_pra.pdf and 3686221171167ADT7460_b.pdf
* https://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
* https://www.onsemi.com/PowerSolutions/product.do?id=ADT7460
*
*/
#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/suspend.h>
#include <linux/kthread.h>
#include <linux/moduleparam.h>
#include <linux/freezer.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#undef DEBUG
#define CONFIG_REG 0x40
#define MANUAL_MASK 0xe0
#define AUTO_MASK 0x20
#define INVERT_MASK 0x10
static u8 TEMP_REG[3] = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
static u8 LIMIT_REG[3] = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
static u8 REM_CONTROL[2] = {0x00, 0x40};
static u8 FAN_SPEED[2] = {0x28, 0x2a};
static u8 FAN_SPD_SET[2] = {0x30, 0x31};
static u8 default_limits_local[3] = {70, 50, 70}; /* local, sensor1, sensor2 */
static u8 default_limits_chip[3] = {80, 65, 80}; /* local, sensor1, sensor2 */
static const char *sensor_location[3] = { "?", "?", "?" };
static int limit_adjust;
static int fan_speed = -1;
static bool verbose;
MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
"Powerbook G4 Alu");
MODULE_LICENSE("GPL");
module_param(limit_adjust, int, 0644);
MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
"by N degrees.");
module_param(fan_speed, int, 0644);
MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
"(default 64)");
module_param(verbose, bool, 0);
MODULE_PARM_DESC(verbose,"Verbose log operations "
"(default 0)");
struct thermostat {
struct i2c_client *clt;
u8 temps[3];
u8 cached_temp[3];
u8 initial_limits[3];
u8 limits[3];
int last_speed[2];
int last_var[2];
int pwm_inv[2];
struct task_struct *thread;
struct platform_device *pdev;
enum {
ADT7460,
ADT7467
} type;
};
static void write_both_fan_speed(struct thermostat *th, int speed);
static void write_fan_speed(struct thermostat *th, int speed, int fan);
static int
write_reg(struct thermostat* th, int reg, u8 data)
{
u8 tmp[2];
int rc;
tmp[0] = reg;
tmp[1] = data;
rc = i2c_master_send(th->clt, (const char *)tmp, 2);
if (rc < 0)
return rc;
if (rc != 2)
return -ENODEV;
return 0;
}
static int
read_reg(struct thermostat* th, int reg)
{
u8 reg_addr, data;
int rc;
reg_addr = (u8)reg;
rc = i2c_master_send(th->clt, ®_addr, 1);
if (rc < 0)
return rc;
if (rc != 1)
return -ENODEV;
rc = i2c_master_recv(th->clt, (char *)&data, 1);
if (rc < 0)
return rc;
return data;
}
static int read_fan_speed(struct thermostat *th, u8 addr)
{
u8 tmp[2];
u16 res;
/* should start with low byte */
tmp[1] = read_reg(th, addr);
tmp[0] = read_reg(th, addr + 1);
res = tmp[1] + (tmp[0] << 8);
/* "a value of 0xffff means that the fan has stopped" */
return (res == 0xffff ? 0 : (90000*60)/res);
}
static void write_both_fan_speed(struct thermostat *th, int speed)
{
write_fan_speed(th, speed, 0);
if (th->type == ADT7460)
write_fan_speed(th, speed, 1);
}
static void write_fan_speed(struct thermostat *th, int speed, int fan)
{
u8 manual;
if (speed > 0xff)
speed = 0xff;
else if (speed < -1)
speed = 0;
if (th->type == ADT7467 && fan == 1)
return;
if (th->last_speed[fan] != speed) {
if (verbose) {
if (speed == -1)
printk(KERN_DEBUG "adt746x: Setting speed to automatic "
"for %s fan.\n", sensor_location[fan+1]);
else
printk(KERN_DEBUG "adt746x: Setting speed to %d "
"for %s fan.\n", speed, sensor_location[fan+1]);
}
} else
return;
if (speed >= 0) {
manual = read_reg(th, MANUAL_MODE[fan]);
manual &= ~INVERT_MASK;
write_reg(th, MANUAL_MODE[fan],
manual | MANUAL_MASK | th->pwm_inv[fan]);
write_reg(th, FAN_SPD_SET[fan], speed);
} else {
/* back to automatic */
if(th->type == ADT7460) {
manual = read_reg(th,
MANUAL_MODE[fan]) & (~MANUAL_MASK);
manual &= ~INVERT_MASK;
manual |= th->pwm_inv[fan];
write_reg(th,
MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
} else {
manual = read_reg(th, MANUAL_MODE[fan]);
manual &= ~INVERT_MASK;
manual |= th->pwm_inv[fan];
write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
}
}
th->last_speed[fan] = speed;
}
static void read_sensors(struct thermostat *th)
{
int i = 0;
for (i = 0; i < 3; i++)
th->temps[i] = read_reg(th, TEMP_REG[i]);
}
#ifdef DEBUG
static void display_stats(struct thermostat *th)
{
if (th->temps[0] != th->cached_temp[0]
|| th->temps[1] != th->cached_temp[1]
|| th->temps[2] != th->cached_temp[2]) {
printk(KERN_INFO "adt746x: Temperature infos:"
" thermostats: %d,%d,%d;"
" limits: %d,%d,%d;"
" fan speed: %d RPM\n",
th->temps[0], th->temps[1], th->temps[2],
th->limits[0], th->limits[1], th->limits[2],
read_fan_speed(th, FAN_SPEED[0]));
}
th->cached_temp[0] = th->temps[0];
th->cached_temp[1] = th->temps[1];
th->cached_temp[2] = th->temps[2];
}
#endif
static void update_fans_speed (struct thermostat *th)
{
int lastvar = 0; /* last variation, for iBook */
int i = 0;
/* we don't care about local sensor, so we start at sensor 1 */
for (i = 1; i < 3; i++) {
bool started = false;
int fan_number = (th->type == ADT7460 && i == 2);
int var = th->temps[i] - th->limits[i];
if (var > -1) {
int step = (255 - fan_speed) / 7;
int new_speed = 0;
/* hysteresis : change fan speed only if variation is
* more than two degrees */
if (abs(var - th->last_var[fan_number]) < 2)
continue;
started = true;
new_speed = fan_speed + ((var-1)*step);
if (new_speed < fan_speed)
new_speed = fan_speed;
if (new_speed > 255)
new_speed = 255;
if (verbose)
printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
"(limit exceeded by %d on %s)\n",
new_speed, var,
sensor_location[fan_number+1]);
write_both_fan_speed(th, new_speed);
th->last_var[fan_number] = var;
} else if (var < -2) {
/* don't stop fan if sensor2 is cold and sensor1 is not
* so cold (lastvar >= -1) */
if (i == 2 && lastvar < -1) {
if (th->last_speed[fan_number] != 0)
if (verbose)
printk(KERN_DEBUG "adt746x: Stopping "
"fans.\n");
write_both_fan_speed(th, 0);
}
}
lastvar = var;
if (started)
return; /* we don't want to re-stop the fan
* if sensor1 is heating and sensor2 is not */
}
}
static int monitor_task(void *arg)
{
struct thermostat* th = arg;
set_freezable();
while(!kthread_should_stop()) {
try_to_freeze();
msleep_interruptible(2000);
#ifndef DEBUG
if (fan_speed != -1)
read_sensors(th);
#else
read_sensors(th);
#endif
if (fan_speed != -1)
update_fans_speed(th);
#ifdef DEBUG
display_stats(th);
#endif
}
return 0;
}
static void set_limit(struct thermostat *th, int i)
{
/* Set sensor1 limit higher to avoid powerdowns */
th->limits[i] = default_limits_chip[i] + limit_adjust;
write_reg(th, LIMIT_REG[i], th->limits[i]);
/* set our limits to normal */
th->limits[i] = default_limits_local[i] + limit_adjust;
}
#define BUILD_SHOW_FUNC_INT(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct thermostat *th = dev_get_drvdata(dev); \
return sprintf(buf, "%d\n", data); \
}
#define BUILD_SHOW_FUNC_INT_LITE(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%d\n", data); \
}
#define BUILD_SHOW_FUNC_STR(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
return sprintf(buf, "%s\n", data); \
}
#define BUILD_SHOW_FUNC_FAN(name, data) \
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct thermostat *th = dev_get_drvdata(dev); \
return sprintf(buf, "%d (%d rpm)\n", \
th->last_speed[data], \
read_fan_speed(th, FAN_SPEED[data]) \
); \
}
#define BUILD_STORE_FUNC_DEG(name, data) \
static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
{ \
struct thermostat *th = dev_get_drvdata(dev); \
int val; \
int i; \
val = simple_strtol(buf, NULL, 10); \
printk(KERN_INFO "Adjusting limits by %d degrees\n", val); \
limit_adjust = val; \
for (i=0; i < 3; i++) \
set_limit(th, i); \
return n; \
}
#define BUILD_STORE_FUNC_INT(name, data) \
static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
{ \
int val; \
val = simple_strtol(buf, NULL, 10); \
if (val < 0 || val > 255) \
return -EINVAL; \
printk(KERN_INFO "Setting specified fan speed to %d\n", val); \
data = val; \
return n; \
}
BUILD_SHOW_FUNC_INT(sensor1_temperature, (read_reg(th, TEMP_REG[1])))
BUILD_SHOW_FUNC_INT(sensor2_temperature, (read_reg(th, TEMP_REG[2])))
BUILD_SHOW_FUNC_INT(sensor1_limit, th->limits[1])
BUILD_SHOW_FUNC_INT(sensor2_limit, th->limits[2])
BUILD_SHOW_FUNC_STR(sensor1_location, sensor_location[1])
BUILD_SHOW_FUNC_STR(sensor2_location, sensor_location[2])
BUILD_SHOW_FUNC_INT_LITE(specified_fan_speed, fan_speed)
BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
BUILD_SHOW_FUNC_FAN(sensor1_fan_speed, 0)
BUILD_SHOW_FUNC_FAN(sensor2_fan_speed, 1)
BUILD_SHOW_FUNC_INT_LITE(limit_adjust, limit_adjust)
BUILD_STORE_FUNC_DEG(limit_adjust, th)
static DEVICE_ATTR(sensor1_temperature, S_IRUGO,
show_sensor1_temperature,NULL);
static DEVICE_ATTR(sensor2_temperature, S_IRUGO,
show_sensor2_temperature,NULL);
static DEVICE_ATTR(sensor1_limit, S_IRUGO,
show_sensor1_limit, NULL);
static DEVICE_ATTR(sensor2_limit, S_IRUGO,
show_sensor2_limit, NULL);
static DEVICE_ATTR(sensor1_location, S_IRUGO,
show_sensor1_location, NULL);
static DEVICE_ATTR(sensor2_location, S_IRUGO,
show_sensor2_location, NULL);
static DEVICE_ATTR(specified_fan_speed, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
show_specified_fan_speed,store_specified_fan_speed);
static DEVICE_ATTR(sensor1_fan_speed, S_IRUGO,
show_sensor1_fan_speed, NULL);
static DEVICE_ATTR(sensor2_fan_speed, S_IRUGO,
show_sensor2_fan_speed, NULL);
static DEVICE_ATTR(limit_adjust, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
show_limit_adjust, store_limit_adjust);
static void thermostat_create_files(struct thermostat *th)
{
struct device_node *np = th->clt->dev.of_node;
struct device *dev;
int err;
/* To maintain ABI compatibility with userspace, create
* the old style platform driver and attach the attributes
* to it here
*/
th->pdev = of_platform_device_create(np, "temperatures", NULL);
if (!th->pdev)
return;
dev = &th->pdev->dev;
dev_set_drvdata(dev, th);
err = device_create_file(dev, &dev_attr_sensor1_temperature);
err |= device_create_file(dev, &dev_attr_sensor2_temperature);
err |= device_create_file(dev, &dev_attr_sensor1_limit);
err |= device_create_file(dev, &dev_attr_sensor2_limit);
err |= device_create_file(dev, &dev_attr_sensor1_location);
err |= device_create_file(dev, &dev_attr_sensor2_location);
err |= device_create_file(dev, &dev_attr_limit_adjust);
err |= device_create_file(dev, &dev_attr_specified_fan_speed);
err |= device_create_file(dev, &dev_attr_sensor1_fan_speed);
if(th->type == ADT7460)
err |= device_create_file(dev, &dev_attr_sensor2_fan_speed);
if (err)
printk(KERN_WARNING
"Failed to create temperature attribute file(s).\n");
}
static void thermostat_remove_files(struct thermostat *th)
{
struct device *dev;
if (!th->pdev)
return;
dev = &th->pdev->dev;
device_remove_file(dev, &dev_attr_sensor1_temperature);
device_remove_file(dev, &dev_attr_sensor2_temperature);
device_remove_file(dev, &dev_attr_sensor1_limit);
device_remove_file(dev, &dev_attr_sensor2_limit);
device_remove_file(dev, &dev_attr_sensor1_location);
device_remove_file(dev, &dev_attr_sensor2_location);
device_remove_file(dev, &dev_attr_limit_adjust);
device_remove_file(dev, &dev_attr_specified_fan_speed);
device_remove_file(dev, &dev_attr_sensor1_fan_speed);
if (th->type == ADT7460)
device_remove_file(dev, &dev_attr_sensor2_fan_speed);
of_device_unregister(th->pdev);
}
static int probe_thermostat(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct device_node *np = client->dev.of_node;
struct thermostat* th;
const __be32 *prop;
int i, rc, vers, offset = 0;
if (!np)
return -ENXIO;
prop = of_get_property(np, "hwsensor-params-version", NULL);
if (!prop)
return -ENXIO;
vers = be32_to_cpup(prop);
printk(KERN_INFO "adt746x: version %d (%ssupported)\n",
vers, vers == 1 ? "" : "un");
if (vers != 1)
return -ENXIO;
if (of_property_present(np, "hwsensor-location")) {
for (i = 0; i < 3; i++) {
sensor_location[i] = of_get_property(np,
"hwsensor-location", NULL) + offset;
if (sensor_location[i] == NULL)
sensor_location[i] = "";
printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
offset += strlen(sensor_location[i]) + 1;
}
}
th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
if (!th)
return -ENOMEM;
i2c_set_clientdata(client, th);
th->clt = client;
th->type = id->driver_data;
rc = read_reg(th, CONFIG_REG);
if (rc < 0) {
dev_err(&client->dev, "Thermostat failed to read config!\n");
kfree(th);
return -ENODEV;
}
/* force manual control to start the fan quieter */
if (fan_speed == -1)
fan_speed = 64;
if (th->type == ADT7460) {
printk(KERN_INFO "adt746x: ADT7460 initializing\n");
/* The 7460 needs to be started explicitly */
write_reg(th, CONFIG_REG, 1);
} else
printk(KERN_INFO "adt746x: ADT7467 initializing\n");
for (i = 0; i < 3; i++) {
th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
set_limit(th, i);
}
printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
" to %d, %d, %d\n",
th->initial_limits[0], th->initial_limits[1],
th->initial_limits[2], th->limits[0], th->limits[1],
th->limits[2]);
/* record invert bit status because fw can corrupt it after suspend */
th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
/* be sure to really write fan speed the first time */
th->last_speed[0] = -2;
th->last_speed[1] = -2;
th->last_var[0] = -80;
th->last_var[1] = -80;
if (fan_speed != -1) {
/* manual mode, stop fans */
write_both_fan_speed(th, 0);
} else {
/* automatic mode */
write_both_fan_speed(th, -1);
}
th->thread = kthread_run(monitor_task, th, "kfand");
if (th->thread == ERR_PTR(-ENOMEM)) {
printk(KERN_INFO "adt746x: Kthread creation failed\n");
th->thread = NULL;
return -ENOMEM;
}
thermostat_create_files(th);
return 0;
}
static void remove_thermostat(struct i2c_client *client)
{
struct thermostat *th = i2c_get_clientdata(client);
int i;
thermostat_remove_files(th);
if (th->thread != NULL)
kthread_stop(th->thread);
printk(KERN_INFO "adt746x: Putting max temperatures back from "
"%d, %d, %d to %d, %d, %d\n",
th->limits[0], th->limits[1], th->limits[2],
th->initial_limits[0], th->initial_limits[1],
th->initial_limits[2]);
for (i = 0; i < 3; i++)
write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
write_both_fan_speed(th, -1);
kfree(th);
}
static const struct i2c_device_id therm_adt746x_id[] = {
{ "MAC,adt7460", ADT7460 },
{ "MAC,adt7467", ADT7467 },
{ }
};
MODULE_DEVICE_TABLE(i2c, therm_adt746x_id);
static struct i2c_driver thermostat_driver = {
.driver = {
.name = "therm_adt746x",
},
.probe = probe_thermostat,
.remove = remove_thermostat,
.id_table = therm_adt746x_id,
};
static int __init thermostat_init(void)
{
#ifndef CONFIG_I2C_POWERMAC
request_module("i2c-powermac");
#endif
return i2c_add_driver(&thermostat_driver);
}
static void __exit thermostat_exit(void)
{
i2c_del_driver(&thermostat_driver);
}
module_init(thermostat_init);
module_exit(thermostat_exit);