Hi Matthew, Hi Len,
I've been improving and testing the acerhdf module the last few days and
here's a new patch. Thank you Matthew for your hints!
Matthew Garrett writes:
> *) It looks like the patch has ended up linewrapped - it probably won't
> apply as a result.
Hope this is fixed now, as I'm now using git diff to create the patch.
> *) x86 specific drivers are mostly moving from drivers/misc to
> drivers/platform/x86.
Done.
> *) It should probably have a DMI modalias to allow it to autoload on
> appropriate hardware.
Done.
> *) You have user and kernel modes - it should probably also have a bios
> mode that just leaves fan control in the same state it would be if the
> driver had never been loaded, and this should be the default.
It's now started in user mode by default. The bios cares in usermode about
the fan unless a userspace program does.
> *) The thermal code has been moved from ACPI into the generic thermal
> layer for 2.6.30. If you register thermal trip points and indicate that
> you require polling you should be able to get rid of the kernel thread
> in your driver and leave that up to the kernel.
Didn't find anything about polling in the drivers/thermal/ yet, but I'll
keep on looking for that.
> Once that's all dealt with you should submit the patch to linux-kernel
> and Cc: Len Brown who maintains drivers/platform/x86. Include a
> description and a signed-off-by: line (and an entry in the MAINTAINERS
> file) and it should get merged.
Here we go:
Acerhdf is a driver for Acer Aspire One netbooks. It allows to access
the temperature sensor and to control the fan.
Signed-off-by: Peter Feuerer <[email protected]>
diff --git a/MAINTAINERS b/MAINTAINERS
index 5d460c9..ed823bc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -189,6 +189,12 @@ M: [email protected]
L: [email protected]
S: Maintained
+ACER ASPIRE ONE TEMPERATURE AND FAN DRIVER
+P: Peter Feuerer
+M: [email protected]
+W: http://piie.net/?section=acerhdf
+S: Maintained
+
ACER WMI LAPTOP EXTRAS
P: Carlos Corbacho
M: [email protected]
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 3608081..4bb04aa 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -34,6 +34,25 @@ config ACER_WMI
If you have an ACPI-WMI compatible Acer/ Wistron laptop, say Y or M
here.
+config ACERHDF
+ tristate "Acer Aspire One temperature and fan driver"
+ depends on THERMAL
+ depends on THERMAL_HWMON
+ ---help---
+ This is a driver for Acer Aspire One netbooks. It allows to access
+ the temperature sensor and to control the fan.
+
+ The driver is started in "user" mode where the Bios takes care about
+ controlling the fan, unless a userspace program controls it.
+ To let the kernelmodule handle the fan, do:
+ echo kernel > /sys/class/thermal/thermal_zone0/mode
+
+ For more information about this driver see
+ <http://piie.net/files/acerhdf_README.txt>
+
+ If you have an Acer Aspire One netbook, say Y or M
+ here.
+
config ASUS_LAPTOP
tristate "Asus Laptop Extras (EXPERIMENTAL)"
depends on ACPI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e290651..01e9353 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_MSI_LAPTOP) += msi-laptop.o
obj-$(CONFIG_COMPAL_LAPTOP) += compal-laptop.o
obj-$(CONFIG_DELL_LAPTOP) += dell-laptop.o
obj-$(CONFIG_ACER_WMI) += acer-wmi.o
+obj-$(CONFIG_ACERHDF) += acerhdf.o
obj-$(CONFIG_HP_WMI) += hp-wmi.o
obj-$(CONFIG_TC1100_WMI) += tc1100-wmi.o
obj-$(CONFIG_SONY_LAPTOP) += sony-laptop.o
diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
new file mode 100644
index 0000000..63e7f1f
--- /dev/null
+++ b/drivers/platform/x86/acerhdf.c
@@ -0,0 +1,646 @@
+/*
+ * acerhdf - A kernelmodule which monitors the temperature
+ * of the aspire one netbook, turns on/off the fan
+ * as soon as the upper/lower threshold is reached.
+ *
+ * (C) 2009 - Peter Feuerer peter (a) piie.net
+ * http://piie.net
+ *
+ *
+ *
+ * Inspired by and many thanks to:
+ * o acerfand - Rachel Greenham
+ * o acer_ec.pl - Michael Kurz michi.kurz (at) googlemail.com
+ * - Petr Tomasek tomasek (#) etf,cuni,cz
+ * - Carlos Corbacho cathectic (at) gmail.com
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * 06-February-2009: Version 0.1:
+ * - first relase, containing absolutely no bugs! ;)
+ *
+ * 06-February-2009: Version 0.1.1:
+ * - found first bug :-) - it didn't check the bios vendor
+ * - check if the bios vendor is Acer
+ * - added bios 3301
+ *
+ * 06-February-2009: Version 0.1.2:
+ * - added fork for deamon mode, now a real daemon is spawned
+ * - added device vendor "INSYDE"
+ *
+ * 13-February-2009: Version 0.2:
+ * - ported to kernelspace
+ *
+ * 19-February-2009: Version 0.2.1:
+ * - added Bios Version 3308
+ * - cleaned up the includes
+ *
+ * 21-February-2009: Version 0.2.2:
+ * - changed settings for Bios 3309 as old settings caused lock ups
+ * - thanks to Frank Reimann
+ *
+ * 21-February-2009: Version 0.2.2-2:
+ * - added linux/sched.h to includes again, as it won't compile for
+ * kernel < 2.6.28 without it.
+ *
+ * 23-February-2009: Version 0.3:
+ * - tied to termal layer
+ * - added parameters to /sys/modules/acerhdf/parameters/
+ *
+ * 25-February-2009: Version 0.3.1:
+ * - fixed starting the module in user mode when force_bios param
+ * is given
+ *
+ * 28-February-2009: Version 0.3.2:
+ * - changed coding style to fit the coding style of the kernel
+ * and checked it via checkpatch
+ *
+ * 24-March-2009: Version 0.4.0:
+ * - added MODULE_ALIAS macro
+ * - added Gateway and Packard Bell Bios
+ * - added suspend / resume functionality
+ *
+ * 25-March-2009: Version 0.4.1:
+ * - coding style
+ * - minor bugfixes
+ *
+ * 26-March-2009: Version 0.4.2:
+ * - replaced kernel threads by kthread api
+ *
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/dmi.h>
+#include <acpi/acpi_drivers.h>
+#include <linux/sched.h>
+#include <linux/thermal.h>
+#include <linux/platform_device.h>
+#include <linux/kthread.h>
+
+#define VERSION "0.4.2"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Peter Feuerer");
+MODULE_DESCRIPTION("Aspire One temperature and fan driver");
+MODULE_ALIAS("dmi:*:*Acer*:*:");
+MODULE_ALIAS("dmi:*:*Gateway*:*:");
+MODULE_ALIAS("dmi:*:*Packard Bell*:*:");
+
+/* thread handling variables / funktions */
+static struct task_struct *thread;
+static struct pid *thread_pid;
+static wait_queue_head_t wq;
+static DECLARE_COMPLETION(on_exit);
+static int acerhdf_thread(void *data);
+
+/* global variables */
+static int interval = 10;
+static int fanon = 67;
+static int fanoff = 62;
+static int verbose;
+static int kernelmode = 0;
+static int fanstate = 1;
+static int bios_version = -1;
+static char force_bios[16];
+struct thermal_zone_device *acerhdf_thz_dev;
+struct thermal_cooling_device *acerhdf_cool_dev;
+
+/* module parameters */
+module_param(interval, int, 0600);
+MODULE_PARM_DESC(interval, "Polling interval of temperature check");
+module_param(fanon, int, 0600);
+MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
+module_param(fanoff, int, 0600);
+MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
+module_param(verbose, int, 0600);
+MODULE_PARM_DESC(verbose, "Enable verbose dmesg outputs");
+module_param_string(force_bios, force_bios, 16, 0);
+MODULE_PARM_DESC(force_bios, "Force bios version and omit bios check");
+
+/* bios settings */
+/**********************************************************************/
+struct bios_settings_t {
+ const char *vendor;
+ const char *version;
+ unsigned char fanreg;
+ unsigned char tempreg;
+ unsigned char cmd_off;
+ unsigned char cmd_auto;
+ unsigned char state_off;
+};
+
+/* some bios versions have different commands and
+ * maybe also different register addresses */
+static const struct bios_settings_t bios_settings[] = {
+ {"Acer", "v0.3109", 0x55, 0x58, 0x1f, 0x00, 0x1f},
+ {"Acer", "v0.3114", 0x55, 0x58, 0x1f, 0x00, 0x1f},
+ {"Acer", "v0.3301", 0x55, 0x58, 0xaf, 0x00, 0xaf},
+ {"Acer", "v0.3304", 0x55, 0x58, 0xaf, 0x00, 0xaf},
+ {"Acer", "v0.3305", 0x55, 0x58, 0xaf, 0x00, 0xaf},
+ {"Acer", "v0.3308", 0x55, 0x58, 0xaf, 0x00, 0xaf},
+ {"Acer", "v0.3309", 0x55, 0x58, 0x21, 0x00, 0x21},
+ {"Gateway", "v0.3103", 0x55, 0x58, 0x21, 0x00, 0x21},
+ {"Packard Bell", "v0.3105", 0x55, 0x58, 0x21, 0x00, 0x21},
+ {"", 0, 0, 0, 0, 0}
+};
+
+
+/* start kthread */
+static int acerhdf_thread_start(void)
+{
+ thread = kthread_run(acerhdf_thread, NULL, "acerhdf");
+ if (IS_ERR(thread))
+ return -1;
+ return 0;
+}
+
+
+/* acer ec functions */
+/**********************************************************************/
+/* switch on/off the fan */
+static void change_fanstate(int state)
+{
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: fan %s\n", state ? "ON" : "OFF");
+
+ ec_write(bios_settings[bios_version].fanreg,
+ state ? bios_settings[bios_version].cmd_auto :
+ bios_settings[bios_version].cmd_off);
+}
+
+/* thread to monitor the temperature and control the fan */
+static int acerhdf_thread(void *data)
+{
+ unsigned long timeout;
+ u8 temp = 0;
+ u8 last_temp = 0;
+ int unchanged_cnt = 0;
+
+ fanstate = 1;
+ daemonize("acerhdf");
+ allow_signal(SIGTERM);
+ thread_pid = task_pid(current);
+ for (;;) {
+ if (!ec_read(bios_settings[bios_version].tempreg, &temp)) {
+ /* print temperature in verbose mode */
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: Temperature is: %d\n",
+ temp);
+
+ /* if temperature is greater than fanon,
+ * switch on fan */
+ if (temp >= fanon && fanstate == 0) {
+ change_fanstate(1);
+ fanstate = 1;
+ }
+ /* if temperature is less than fanoff,
+ * switch off fan */
+ else if (temp < fanoff && fanstate == 1) {
+ change_fanstate(0);
+ fanstate = 0;
+ }
+ }
+
+ /* sleep interval seconds */
+ timeout = HZ*interval;
+ timeout = wait_event_interruptible_timeout(wq,
+ (timeout == 0), timeout);
+
+ /* if wait was interrupted by SIGTERM, end thread */
+ if (timeout == -ERESTARTSYS) {
+ printk(KERN_NOTICE "acerhdf: ending kernelmode\n");
+ break;
+ }
+
+ /* check if read temperature is reasonable. If not,
+ * change to user mode and turn on fan to save the
+ * hardware */
+ if (last_temp == temp && temp < 30) {
+ if (unchanged_cnt++ >= 10) {
+ printk(KERN_ERR
+ "acerhdf: cannot read temperature:\n");
+ printk(KERN_ERR
+ "acerhdf: switching to user mode\n");
+ kernelmode = 0;
+ break;
+ }
+ } else
+ unchanged_cnt = 0;
+
+ last_temp = temp;
+ }
+ /* turn on fan before ending the thread */
+ change_fanstate(1);
+ thread_pid = NULL;
+ complete_and_exit(&on_exit, 0);
+}
+
+/* thermal zone callback functions */
+/**********************************************************************/
+static int get_ec_temp(struct thermal_zone_device *thermal, char *buf)
+{
+ u8 temp;
+ /* return temperature */
+ if (!ec_read(bios_settings[bios_version].tempreg, &temp))
+ return sprintf(buf, "%d\n", temp);
+
+ return -EINVAL;
+}
+
+/* bind the cooling device to the thermal zone */
+static int bind(struct thermal_zone_device *thermal,
+ struct thermal_cooling_device *cdev)
+{
+ /* if the cooling device is the one from acerhdf bind it */
+ if (cdev == acerhdf_cool_dev) {
+ if (thermal_zone_bind_cooling_device(thermal, 0, cdev)) {
+ printk(KERN_ERR
+ "acerhdf: error binding cooling dev\n");
+ return -EINVAL;
+ }
+ if (thermal_zone_bind_cooling_device(thermal, 1, cdev)) {
+ printk(KERN_ERR
+ "acerhdf: error binding cooling dev\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+/* unbind cooling device from thermal zone */
+static int unbind(struct thermal_zone_device *thermal,
+ struct thermal_cooling_device *cdev)
+{
+ if (cdev == acerhdf_cool_dev) {
+ if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
+ printk(KERN_ERR
+ "acerhdf: error unbinding cooling dev\n");
+ return -EINVAL;
+ }
+ if (thermal_zone_unbind_cooling_device(thermal, 1, cdev)) {
+ printk(KERN_ERR
+ "acerhdf: error unbinding cooling dev\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+/* print currend operation mode - kernel / user */
+static int get_mode(struct thermal_zone_device *thermal,
+ char *buf)
+{
+ if (!kernelmode)
+ return sprintf(buf, "user\n");
+
+ else
+ return sprintf(buf, "kernel\n");
+
+ return 0;
+}
+
+/* set operation mode;
+ * kernel: a kernel thread takes care about managing the
+ * fan (see acerhdf_thread)
+ * user: kernel thread is stopped and a userspace tool
+ * should take care about managing the fan
+ */
+static int set_mode(struct thermal_zone_device *thermal,
+ const char *buf)
+{
+ /* set mode to user mode */
+ if (!strncmp(buf, "user", 4)) {
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: set to usermode\n");
+
+ /* send SIGTERM to thread and wait until thread died */
+ if (thread_pid)
+ kill_pid(thread_pid, SIGTERM, 1);
+
+ wait_for_completion(&on_exit);
+ kernelmode = 0;
+ return 0;
+ }
+ /* set to kernel mode */
+ else if (!strncmp(buf, "kernel", 6)) {
+ /* start acerhdf_thread */
+ if (!kernelmode) {
+ if (acerhdf_thread_start())
+ return -EIO;
+ }
+
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: set to kernelmode\n");
+
+ kernelmode = 1;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+/* print the name of the trip point */
+static int get_trip_type(struct thermal_zone_device *thermal,
+ int trip, char *buf)
+{
+ if (trip == 0)
+ return sprintf(buf, "fanoff\n");
+
+ else if (trip == 1)
+ return sprintf(buf, "fanon\n");
+
+ return 0;
+}
+
+/* print the temperature at which the trip point gets active */
+static int get_trip_temp(struct thermal_zone_device *thermal,
+ int trip, char *buf)
+{
+ if (trip == 0)
+ return sprintf(buf, "%d\n", fanoff);
+
+ else if (trip == 1)
+ return sprintf(buf, "%d\n", fanon);
+
+ return 0;
+}
+
+static int get_crit_temp(struct thermal_zone_device *thermal,
+ unsigned long *temperature)
+{
+ return 0;
+}
+
+/* bind callback functions to thermalzone */
+struct thermal_zone_device_ops acerhdf_device_ops = {
+ .bind = bind,
+ .unbind = unbind,
+ .get_temp = get_ec_temp,
+ .get_mode = get_mode,
+ .set_mode = set_mode,
+ .get_trip_type = get_trip_type,
+ .get_trip_temp = get_trip_temp,
+ .get_crit_temp = get_crit_temp,
+};
+
+
+/* cooling device callback functions */
+/**********************************************************************/
+/* print maximal fan cooling state */
+static int get_max_state(struct thermal_cooling_device *cdev, char *buf)
+{
+ return sprintf(buf, "1\n");
+}
+
+/* print current fan state */
+static int get_cur_state(struct thermal_cooling_device *cdev, char *buf)
+{
+ u8 fan;
+ if (!ec_read(bios_settings[bios_version].fanreg, &fan)) {
+ return sprintf(buf, "%d\n",
+ (fan == bios_settings[bios_version].cmd_auto));
+ }
+ return 0;
+}
+
+/* change current fan state - is overwritten when running in kernel mode */
+static int set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned int state)
+{
+ if (kernelmode) {
+ printk(KERN_ERR
+ "acerhdf: cannot change fanstate in kernelmode\n");
+ return -EINVAL;
+ }
+
+ change_fanstate(state);
+ return 0;
+}
+
+/* bind fan callbacks to fan device */
+struct thermal_cooling_device_ops acerhdf_cooling_ops = {
+ .get_max_state = get_max_state,
+ .get_cur_state = get_cur_state,
+ .set_cur_state = set_cur_state,
+};
+
+/* platform callbacks */
+/**********************************************************************/
+/* go suspend */
+static int acerhdf_suspend(struct platform_device *dev,
+ pm_message_t state)
+{
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: going suspend\n");
+ /* send SIGTERM to thread and wait until thread died */
+ if (thread_pid)
+ kill_pid(thread_pid, SIGTERM, 1);
+
+ wait_for_completion(&on_exit);
+ return 0;
+}
+
+/* wake up */
+static int acerhdf_resume(struct platform_device *device)
+{
+ if (verbose)
+ printk(KERN_NOTICE "acerhdf: resuming\n");
+ if (kernelmode) {
+ if (acerhdf_thread_start())
+ return -EIO;
+ }
+ return 0;
+}
+
+/* platform probe */
+static int __devinit acerhdf_probe(struct platform_device *device)
+{
+ return 0;
+}
+
+static int acerhdf_remove(struct platform_device *device)
+{
+ return 0;
+}
+
+static struct platform_driver acerhdf_driver = {
+ .driver = {
+ .name = "acerhdf",
+ .owner = THIS_MODULE,
+ },
+ .probe = acerhdf_probe,
+ .remove = acerhdf_remove,
+ .suspend = acerhdf_suspend,
+ .resume = acerhdf_resume,
+};
+
+static struct platform_device *acerhdf_device;
+
+/* kernel module init / exit functions */
+/**********************************************************************/
+/* initialize the module */
+static int __init acerhdf_init(void)
+{
+ char const *vendor;
+ char const *version;
+ char const *release;
+ char const *product;
+ int i;
+ int ret_val = 0;
+
+
+ /* get bios data */
+ vendor = dmi_get_system_info(DMI_SYS_VENDOR);
+ version = dmi_get_system_info(DMI_BIOS_VERSION);
+ release = dmi_get_system_info(DMI_BIOS_DATE);
+ product = dmi_get_system_info(DMI_PRODUCT_NAME);
+
+
+ /* print out bios data */
+ printk(KERN_NOTICE "acerhdf: version: %s compilation date: %s %s\n",
+ VERSION, __DATE__, __TIME__);
+ printk(KERN_NOTICE "acerhdf: biosvendor:%s\n", vendor);
+ printk(KERN_NOTICE "acerhdf: biosversion:%s\n", version);
+ printk(KERN_NOTICE "acerhdf: biosrelease:%s\n", release);
+ printk(KERN_NOTICE "acerhdf: biosproduct:%s\n", product);
+
+ if (!force_bios[0]) {
+ /* check if product is a AO - Aspire One */
+ if (strncmp(product, "AO", 2)) {
+ printk(KERN_ERR
+ "acerhdf: no Aspire One hardware found\n");
+ ret_val = -ENODEV;
+ goto EXIT;
+ }
+ } else {
+ printk(KERN_NOTICE
+ "acerhdf: bios version: %s forced\n",
+ version);
+ printk(KERN_NOTICE
+ "acerhdf: kernelmode disabled\n");
+ printk(KERN_NOTICE
+ "acerhdf: for more information read:\n");
+ printk(KERN_NOTICE
+ "acerhdf: http://piie.net/files/acerhdf_README.txt\n");
+ version = force_bios;
+ kernelmode = 0;
+ }
+
+ /* search bios and bios vendor in bios settings table */
+ for (i = 0; bios_settings[i].version[0]; ++i) {
+ if (!strcmp(bios_settings[i].vendor, vendor) &&
+ !strcmp(bios_settings[i].version, version)) {
+ bios_version = i;
+ break;
+ }
+ }
+ if (bios_version == -1) {
+ printk(KERN_ERR "acerhdf: cannot find bios version\n");
+ ret_val = -ENODEV;
+ goto EXIT;
+ }
+
+ /* register platform device */
+ if (platform_driver_register(&acerhdf_driver)) {
+ ret_val = -ENODEV;
+ goto EXIT;
+ }
+ acerhdf_device = platform_device_alloc("acerhdf", -1);
+ platform_device_add(acerhdf_device);
+
+ /* create cooling device */
+ acerhdf_cool_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
+ &acerhdf_cooling_ops);
+ if (IS_ERR(acerhdf_cool_dev)) {
+ ret_val = -ENODEV;
+ goto EXIT_PLAT_UNREG;
+ }
+
+ /* create thermal zone */
+ acerhdf_thz_dev = thermal_zone_device_register("acerhdf", 2,
+ NULL, &acerhdf_device_ops);
+ if (IS_ERR(acerhdf_thz_dev)) {
+ ret_val = -ENODEV;
+ goto EXIT_COOL_UNREG;
+ }
+
+ init_waitqueue_head(&wq);
+ /* start acerhdf_thread */
+ if (kernelmode) {
+ if (acerhdf_thread_start()) {
+ ret_val = -EIO;
+ goto EXIT_THERM_UNREG;
+ }
+ }
+ goto EXIT;
+
+EXIT_THERM_UNREG:
+ /* unregister thermal zone */
+ if (acerhdf_thz_dev) {
+ thermal_zone_device_unregister(acerhdf_thz_dev);
+ acerhdf_thz_dev = NULL;
+ }
+
+EXIT_COOL_UNREG:
+ /* unregister cooling device */
+ if (acerhdf_cool_dev) {
+ thermal_cooling_device_unregister(acerhdf_cool_dev);
+ acerhdf_cool_dev = NULL;
+ }
+
+EXIT_PLAT_UNREG:
+ /* unregister platform device */
+ if (acerhdf_device) {
+ platform_device_del(acerhdf_device);
+ platform_driver_unregister(&acerhdf_driver);
+ }
+
+EXIT:
+ return ret_val;
+}
+
+/* exit the module */
+static void __exit acerhdf_exit(void)
+{
+ /* unregister cooling device */
+ if (acerhdf_cool_dev) {
+ thermal_cooling_device_unregister(acerhdf_cool_dev);
+ acerhdf_cool_dev = NULL;
+ }
+ /* unregister thermal zone */
+ if (acerhdf_thz_dev) {
+ thermal_zone_device_unregister(acerhdf_thz_dev);
+ acerhdf_thz_dev = NULL;
+ }
+ /* send SIGTERM to thread */
+ if (thread_pid) {
+ kill_pid(thread_pid, SIGTERM, 1);
+ wait_for_completion(&on_exit);
+ }
+
+ /* unregister platform device */
+ if (acerhdf_device) {
+ platform_device_del(acerhdf_device);
+ platform_driver_unregister(&acerhdf_driver);
+ }
+}
+
+/* what are the module init/exit functions */
+module_init(acerhdf_init);
+module_exit(acerhdf_exit);