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path: root/drivers/acpi/thermal.c
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-rw-r--r--drivers/acpi/thermal.c68
1 files changed, 38 insertions, 30 deletions
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index e8c143caf0f..9cd15e8c893 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -98,6 +98,7 @@ MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
static int acpi_thermal_add(struct acpi_device *device);
static int acpi_thermal_remove(struct acpi_device *device, int type);
static int acpi_thermal_resume(struct acpi_device *device);
+static void acpi_thermal_notify(struct acpi_device *device, u32 event);
static int acpi_thermal_state_open_fs(struct inode *inode, struct file *file);
static int acpi_thermal_temp_open_fs(struct inode *inode, struct file *file);
static int acpi_thermal_trip_open_fs(struct inode *inode, struct file *file);
@@ -123,6 +124,7 @@ static struct acpi_driver acpi_thermal_driver = {
.add = acpi_thermal_add,
.remove = acpi_thermal_remove,
.resume = acpi_thermal_resume,
+ .notify = acpi_thermal_notify,
},
};
@@ -192,6 +194,7 @@ struct acpi_thermal {
struct acpi_handle_list devices;
struct thermal_zone_device *thermal_zone;
int tz_enabled;
+ int kelvin_offset;
struct mutex lock;
};
@@ -581,7 +584,7 @@ static void acpi_thermal_check(void *data)
}
/* sys I/F for generic thermal sysfs support */
-#define KELVIN_TO_MILLICELSIUS(t) (t * 100 - 273200)
+#define KELVIN_TO_MILLICELSIUS(t, off) (((t) - (off)) * 100)
static int thermal_get_temp(struct thermal_zone_device *thermal,
unsigned long *temp)
@@ -596,7 +599,7 @@ static int thermal_get_temp(struct thermal_zone_device *thermal,
if (result)
return result;
- *temp = KELVIN_TO_MILLICELSIUS(tz->temperature);
+ *temp = KELVIN_TO_MILLICELSIUS(tz->temperature, tz->kelvin_offset);
return 0;
}
@@ -702,7 +705,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
if (tz->trips.critical.flags.valid) {
if (!trip) {
*temp = KELVIN_TO_MILLICELSIUS(
- tz->trips.critical.temperature);
+ tz->trips.critical.temperature,
+ tz->kelvin_offset);
return 0;
}
trip--;
@@ -711,7 +715,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
if (tz->trips.hot.flags.valid) {
if (!trip) {
*temp = KELVIN_TO_MILLICELSIUS(
- tz->trips.hot.temperature);
+ tz->trips.hot.temperature,
+ tz->kelvin_offset);
return 0;
}
trip--;
@@ -720,7 +725,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
if (tz->trips.passive.flags.valid) {
if (!trip) {
*temp = KELVIN_TO_MILLICELSIUS(
- tz->trips.passive.temperature);
+ tz->trips.passive.temperature,
+ tz->kelvin_offset);
return 0;
}
trip--;
@@ -730,7 +736,8 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
tz->trips.active[i].flags.valid; i++) {
if (!trip) {
*temp = KELVIN_TO_MILLICELSIUS(
- tz->trips.active[i].temperature);
+ tz->trips.active[i].temperature,
+ tz->kelvin_offset);
return 0;
}
trip--;
@@ -745,7 +752,8 @@ static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
if (tz->trips.critical.flags.valid) {
*temperature = KELVIN_TO_MILLICELSIUS(
- tz->trips.critical.temperature);
+ tz->trips.critical.temperature,
+ tz->kelvin_offset);
return 0;
} else
return -EINVAL;
@@ -1264,17 +1272,14 @@ static int acpi_thermal_remove_fs(struct acpi_device *device)
Driver Interface
-------------------------------------------------------------------------- */
-static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
+static void acpi_thermal_notify(struct acpi_device *device, u32 event)
{
- struct acpi_thermal *tz = data;
- struct acpi_device *device = NULL;
+ struct acpi_thermal *tz = acpi_driver_data(device);
if (!tz)
return;
- device = tz->device;
-
switch (event) {
case ACPI_THERMAL_NOTIFY_TEMPERATURE:
acpi_thermal_check(tz);
@@ -1298,8 +1303,6 @@ static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data)
"Unsupported event [0x%x]\n", event));
break;
}
-
- return;
}
static int acpi_thermal_get_info(struct acpi_thermal *tz)
@@ -1334,10 +1337,28 @@ static int acpi_thermal_get_info(struct acpi_thermal *tz)
return 0;
}
+/*
+ * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
+ * handles temperature values with a single decimal place. As a consequence,
+ * some implementations use an offset of 273.1 and others use an offset of
+ * 273.2. Try to find out which one is being used, to present the most
+ * accurate and visually appealing number.
+ *
+ * The heuristic below should work for all ACPI thermal zones which have a
+ * critical trip point with a value being a multiple of 0.5 degree Celsius.
+ */
+static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
+{
+ if (tz->trips.critical.flags.valid &&
+ (tz->trips.critical.temperature % 5) == 1)
+ tz->kelvin_offset = 2731;
+ else
+ tz->kelvin_offset = 2732;
+}
+
static int acpi_thermal_add(struct acpi_device *device)
{
int result = 0;
- acpi_status status = AE_OK;
struct acpi_thermal *tz = NULL;
@@ -1360,6 +1381,8 @@ static int acpi_thermal_add(struct acpi_device *device)
if (result)
goto free_memory;
+ acpi_thermal_guess_offset(tz);
+
result = acpi_thermal_register_thermal_zone(tz);
if (result)
goto free_memory;
@@ -1368,21 +1391,11 @@ static int acpi_thermal_add(struct acpi_device *device)
if (result)
goto unregister_thermal_zone;
- status = acpi_install_notify_handler(device->handle,
- ACPI_DEVICE_NOTIFY,
- acpi_thermal_notify, tz);
- if (ACPI_FAILURE(status)) {
- result = -ENODEV;
- goto remove_fs;
- }
-
printk(KERN_INFO PREFIX "%s [%s] (%ld C)\n",
acpi_device_name(device), acpi_device_bid(device),
KELVIN_TO_CELSIUS(tz->temperature));
goto end;
-remove_fs:
- acpi_thermal_remove_fs(device);
unregister_thermal_zone:
thermal_zone_device_unregister(tz->thermal_zone);
free_memory:
@@ -1393,7 +1406,6 @@ end:
static int acpi_thermal_remove(struct acpi_device *device, int type)
{
- acpi_status status = AE_OK;
struct acpi_thermal *tz = NULL;
if (!device || !acpi_driver_data(device))
@@ -1401,10 +1413,6 @@ static int acpi_thermal_remove(struct acpi_device *device, int type)
tz = acpi_driver_data(device);
- status = acpi_remove_notify_handler(device->handle,
- ACPI_DEVICE_NOTIFY,
- acpi_thermal_notify);
-
acpi_thermal_remove_fs(device);
acpi_thermal_unregister_thermal_zone(tz);
mutex_destroy(&tz->lock);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-24 00:37:31 +0000