Quelle  therm_adt746x.c   Sprache: C

// 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 ");
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);