[PATCH v2] thermal: Make it simpler to use the thermal layer inside the kernel

From: Matthew Garrett
Date: Wed Oct 01 2008 - 14:41:31 EST

The thermal layer passes temperatures and trip point types around as
strings. This is fine for sysfs, but makes it hard to use them for other
purposes in-kernel. Move the string conversion to the sysfs-specific
code.

Signed-off-by: Matthew Garrett <mjg@xxxxxxxxxx>

---

This version also moves the mode setting (user/kernel) away from using
strings, which gets them out of the majority of the API.

diff --git a/drivers/acpi/fan.c b/drivers/acpi/fan.c
index 2655bc1..5487a98 100644
--- a/drivers/acpi/fan.c
+++ b/drivers/acpi/fan.c
@@ -69,27 +69,30 @@ static struct acpi_driver acpi_fan_driver = {
};

/* thermal cooling device callbacks */
-static int fan_get_max_state(struct thermal_cooling_device *cdev, char *buf)
+static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned int
+ *state)
{
/* ACPI fan device only support two states: ON/OFF */
- return sprintf(buf, "1\n");
+ *state = 1;
+ return 0;
}

-static int fan_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
+static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned int
+ *state)
{
struct acpi_device *device = cdev->devdata;
- int state;
int result;

if (!device)
return -EINVAL;

- result = acpi_bus_get_power(device->handle, &state);
+ result = acpi_bus_get_power(device->handle, state);
if (result)
return result;

- return sprintf(buf, "%s\n", state == ACPI_STATE_D3 ? "0" :
- (state == ACPI_STATE_D0 ? "1" : "unknown"));
+ *state = (*state == ACPI_STATE_D3 ? 0 :
+ (*state == ACPI_STATE_D0 ? 1 : -1));
+ return 0;
}

static int
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index ef34b18..4bc094c 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -374,7 +374,8 @@ static int acpi_processor_max_state(struct acpi_processor *pr)
return max_state;
}
static int
-processor_get_max_state(struct thermal_cooling_device *cdev, char *buf)
+processor_get_max_state(struct thermal_cooling_device *cdev, unsigned int
+ *state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_processor *pr = acpi_driver_data(device);
@@ -382,24 +383,24 @@ processor_get_max_state(struct thermal_cooling_device *cdev, char *buf)
if (!device || !pr)
return -EINVAL;

- return sprintf(buf, "%d\n", acpi_processor_max_state(pr));
+ *state = acpi_processor_max_state(pr);
+ return 0;
}

static int
-processor_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
+processor_get_cur_state(struct thermal_cooling_device *cdev, unsigned int
+ *cur_state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_processor *pr = acpi_driver_data(device);
- int cur_state;

if (!device || !pr)
return -EINVAL;

- cur_state = cpufreq_get_cur_state(pr->id);
+ *cur_state = cpufreq_get_cur_state(pr->id);
if (pr->flags.throttling)
- cur_state += pr->throttling.state;
-
- return sprintf(buf, "%d\n", cur_state);
+ *cur_state += pr->throttling.state;
+ return 0;
}

static int
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 9127036..2e4e2a1 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -934,7 +934,8 @@ static void acpi_thermal_check(void *data)
/* sys I/F for generic thermal sysfs support */
#define KELVIN_TO_MILLICELSIUS(t) (t * 100 - 273200)

-static int thermal_get_temp(struct thermal_zone_device *thermal, char *buf)
+static int thermal_get_temp(struct thermal_zone_device *thermal,
+ int *temp)
{
struct acpi_thermal *tz = thermal->devdata;
int result;
@@ -946,25 +947,25 @@ static int thermal_get_temp(struct thermal_zone_device *thermal, char *buf)
if (result)
return result;

- return sprintf(buf, "%ld\n", KELVIN_TO_MILLICELSIUS(tz->temperature));
+ *temp = KELVIN_TO_MILLICELSIUS(tz->temperature);
+ return 0;
}

-static const char enabled[] = "kernel";
-static const char disabled[] = "user";
static int thermal_get_mode(struct thermal_zone_device *thermal,
- char *buf)
+ enum thermal_mode_t *thermal_mode)
{
struct acpi_thermal *tz = thermal->devdata;

if (!tz)
return -EINVAL;

- return sprintf(buf, "%s\n", tz->tz_enabled ?
- enabled : disabled);
+ *thermal_mode = tz->tz_enabled ? THERMAL_MODE_KERNEL
+ : THERMAL_MODE_USER;
+ return 0;
}

static int thermal_set_mode(struct thermal_zone_device *thermal,
- const char *buf)
+ enum thermal_mode_t thermal_mode)
{
struct acpi_thermal *tz = thermal->devdata;
int enable;
@@ -975,12 +976,10 @@ static int thermal_set_mode(struct thermal_zone_device *thermal,
/*
* enable/disable thermal management from ACPI thermal driver
*/
- if (!strncmp(buf, enabled, sizeof enabled - 1))
+ if (thermal_mode == THERMAL_MODE_KERNEL)
enable = 1;
- else if (!strncmp(buf, disabled, sizeof disabled - 1))
- enable = 0;
else
- return -EINVAL;
+ enable = 0;

if (enable != tz->tz_enabled) {
tz->tz_enabled = enable;
@@ -993,7 +992,7 @@ static int thermal_set_mode(struct thermal_zone_device *thermal,
}

static int thermal_get_trip_type(struct thermal_zone_device *thermal,
- int trip, char *buf)
+ int trip, enum thermal_trip_t *type)
{
struct acpi_thermal *tz = thermal->devdata;
int i;
@@ -1002,27 +1001,35 @@ static int thermal_get_trip_type(struct thermal_zone_device *thermal,
return -EINVAL;

if (tz->trips.critical.flags.valid) {
- if (!trip)
- return sprintf(buf, "critical\n");
+ if (!trip) {
+ *type = THERMAL_TRIP_CRITICAL;
+ return 0;
+ }
trip--;
}

if (tz->trips.hot.flags.valid) {
- if (!trip)
- return sprintf(buf, "hot\n");
+ if (!trip) {
+ *type = THERMAL_TRIP_HOT;
+ return 0;
+ }
trip--;
}

if (tz->trips.passive.flags.valid) {
- if (!trip)
- return sprintf(buf, "passive\n");
+ if (!trip) {
+ *type = THERMAL_TRIP_PASSIVE;
+ return 0;
+ }
trip--;
}

for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
tz->trips.active[i].flags.valid; i++) {
- if (!trip)
- return sprintf(buf, "active%d\n", i);
+ if (!trip) {
+ *type = THERMAL_TRIP_ACTIVE;
+ return 0;
+ }
trip--;
}

@@ -1030,7 +1037,7 @@ static int thermal_get_trip_type(struct thermal_zone_device *thermal,
}

static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
- int trip, char *buf)
+ int trip, int *temp)
{
struct acpi_thermal *tz = thermal->devdata;
int i;
@@ -1039,31 +1046,40 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
return -EINVAL;

if (tz->trips.critical.flags.valid) {
- if (!trip)
- return sprintf(buf, "%ld\n", KELVIN_TO_MILLICELSIUS(
- tz->trips.critical.temperature));
+ if (!trip) {
+ *temp = KELVIN_TO_MILLICELSIUS(
+ tz->trips.critical.temperature);
+ return 0;
+ }
+
trip--;
}

if (tz->trips.hot.flags.valid) {
- if (!trip)
- return sprintf(buf, "%ld\n", KELVIN_TO_MILLICELSIUS(
- tz->trips.hot.temperature));
+ if (!trip) {
+ *temp = KELVIN_TO_MILLICELSIUS(
+ tz->trips.hot.temperature);
+ return 0;
+ }
trip--;
}

if (tz->trips.passive.flags.valid) {
- if (!trip)
- return sprintf(buf, "%ld\n", KELVIN_TO_MILLICELSIUS(
- tz->trips.passive.temperature));
+ if (!trip) {
+ *temp = KELVIN_TO_MILLICELSIUS(
+ tz->trips.passive.temperature);
+ return 0;
+ }
trip--;
}

for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
tz->trips.active[i].flags.valid; i++) {
- if (!trip)
- return sprintf(buf, "%ld\n", KELVIN_TO_MILLICELSIUS(
- tz->trips.active[i].temperature));
+ if (!trip) {
+ *temp = KELVIN_TO_MILLICELSIUS(
+ tz->trips.active[i].temperature);
+ return 0;
+ }
trip--;
}

@@ -1071,7 +1087,7 @@ static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
}

static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
- unsigned long *temperature) {
+ int *temperature) {
struct acpi_thermal *tz = thermal->devdata;

if (tz->trips.critical.flags.valid) {
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index e8a51a1..bac2901 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -358,26 +358,30 @@ static struct output_properties acpi_output_properties = {


/* thermal cooling device callbacks */
-static int video_get_max_state(struct thermal_cooling_device *cdev, char *buf)
+static int video_get_max_state(struct thermal_cooling_device *cdev, unsigned
+ int *state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_video_device *video = acpi_driver_data(device);

- return sprintf(buf, "%d\n", video->brightness->count - 3);
+ *state = video->brightness->count - 3;
+ return 0;
}

-static int video_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
+static int video_get_cur_state(struct thermal_cooling_device *cdev, unsigned
+ int *state)
{
struct acpi_device *device = cdev->devdata;
struct acpi_video_device *video = acpi_driver_data(device);
unsigned long level;
- int state;
+ int offset;

acpi_video_device_lcd_get_level_current(video, &level);
- for (state = 2; state < video->brightness->count; state++)
- if (level == video->brightness->levels[state])
- return sprintf(buf, "%d\n",
- video->brightness->count - state - 1);
+ for (offset = 2; offset < video->brightness->count; offset++)
+ if (level == video->brightness->levels[offset]) {
+ *state = video->brightness->count - offset - 1;
+ return 0;
+ }

return -EINVAL;
}
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index fe07462..c1f7e65 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -104,22 +104,41 @@ static ssize_t
temp_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
+ int temperature;
+ int ret;

if (!tz->ops->get_temp)
return -EPERM;

- return tz->ops->get_temp(tz, buf);
+ ret = tz->ops->get_temp(tz, &temperature);
+
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%d\n", temperature);
}

static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
+ enum thermal_mode_t mode;
+ int ret;

if (!tz->ops->get_mode)
return -EPERM;

- return tz->ops->get_mode(tz, buf);
+ ret = tz->ops->get_mode(tz, &mode);
+
+ if (ret)
+ return ret;
+
+ if (mode == THERMAL_MODE_KERNEL)
+ return sprintf(buf, "%s\n", "kernel");
+ else if (mode == THERMAL_MODE_USER)
+ return sprintf(buf, "%s\n", "user");
+ else
+ return sprintf(buf, "%s\n", "unknown");
}

static ssize_t
@@ -132,7 +151,13 @@ mode_store(struct device *dev, struct device_attribute *attr,
if (!tz->ops->set_mode)
return -EPERM;

- result = tz->ops->set_mode(tz, buf);
+ if (!strncmp(buf, "kernel", count))
+ result = tz->ops->set_mode(tz, THERMAL_MODE_KERNEL);
+ else if (!strncmp(buf, "user", count))
+ result = tz->ops->set_mode(tz, THERMAL_MODE_USER);
+ else
+ return -EINVAL;
+
if (result)
return result;

@@ -145,6 +170,8 @@ trip_point_type_show(struct device *dev, struct device_attribute *attr,
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip;
+ enum thermal_trip_t trip_type;
+ int ret;

if (!tz->ops->get_trip_type)
return -EPERM;
@@ -152,7 +179,28 @@ trip_point_type_show(struct device *dev, struct device_attribute *attr,
if (!sscanf(attr->attr.name, "trip_point_%d_type", &trip))
return -EINVAL;

- return tz->ops->get_trip_type(tz, trip, buf);
+
+ ret = tz->ops->get_trip_type(tz, trip, &trip_type);
+ if (ret)
+ return ret;
+
+ switch (trip_type) {
+ case THERMAL_TRIP_CRITICAL:
+ return sprintf(buf, "critical\n");
+ break;
+ case THERMAL_TRIP_HOT:
+ return sprintf(buf, "hot\n");
+ break;
+ case THERMAL_TRIP_PASSIVE:
+ return sprintf(buf, "passive\n");
+ break;
+ case THERMAL_TRIP_ACTIVE:
+ return sprintf(buf, "active\n");
+ break;
+ default:
+ return sprintf(buf, "unknown\n");
+ break;
+ }
}

static ssize_t
@@ -160,7 +208,8 @@ trip_point_temp_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
- int trip;
+ int trip, ret;
+ int temperature;

if (!tz->ops->get_trip_temp)
return -EPERM;
@@ -168,7 +217,12 @@ trip_point_temp_show(struct device *dev, struct device_attribute *attr,
if (!sscanf(attr->attr.name, "trip_point_%d_temp", &trip))
return -EINVAL;

- return tz->ops->get_trip_temp(tz, trip, buf);
+ ret = tz->ops->get_trip_temp(tz, trip, &temperature);
+
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%d\n", temperature);
}

static DEVICE_ATTR(type, 0444, type_show, NULL);
@@ -236,8 +290,12 @@ thermal_cooling_device_max_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ int state, ret;

- return cdev->ops->get_max_state(cdev, buf);
+ ret = cdev->ops->get_max_state(cdev, &state);
+ if (ret)
+ return ret;
+ return sprintf(buf, "%d\n", state);
}

static ssize_t
@@ -245,8 +303,12 @@ thermal_cooling_device_cur_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ int state, ret;

- return cdev->ops->get_cur_state(cdev, buf);
+ ret = cdev->ops->get_cur_state(cdev, &state);
+ if (ret)
+ return ret;
+ return sprintf(buf, "%d\n", state);
}

static ssize_t
@@ -312,13 +374,20 @@ static DEVICE_ATTR(name, 0444, name_show, NULL);
static ssize_t
temp_input_show(struct device *dev, struct device_attribute *attr, char *buf)
{
+ long temperature;
+ int ret;
struct thermal_hwmon_attr *hwmon_attr
= container_of(attr, struct thermal_hwmon_attr, attr);
struct thermal_zone_device *tz
= container_of(hwmon_attr, struct thermal_zone_device,
temp_input);

- return tz->ops->get_temp(tz, buf);
+ ret = tz->ops->get_temp(tz, &temperature);
+
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%ld\n", temperature);
}

static ssize_t
@@ -330,8 +399,14 @@ temp_crit_show(struct device *dev, struct device_attribute *attr,
struct thermal_zone_device *tz
= container_of(hwmon_attr, struct thermal_zone_device,
temp_crit);
+ long temperature;
+ int ret;
+
+ ret = tz->ops->get_trip_temp(tz, 0, &temperature);
+ if (ret)
+ return ret;

- return tz->ops->get_trip_temp(tz, 0, buf);
+ return sprintf(buf, "%ld\n", temperature);
}


diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 917707e..05e56d8 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -28,6 +28,12 @@
#include <linux/idr.h>
#include <linux/device.h>

+enum thermal_trip_t { THERMAL_TRIP_CRITICAL, THERMAL_TRIP_HOT,
+ THERMAL_TRIP_PASSIVE, THERMAL_TRIP_ACTIVE
+};
+
+enum thermal_mode_t { THERMAL_MODE_KERNEL, THERMAL_MODE_USER };
+
struct thermal_zone_device;
struct thermal_cooling_device;

@@ -36,17 +42,19 @@ struct thermal_zone_device_ops {
struct thermal_cooling_device *);
int (*unbind) (struct thermal_zone_device *,
struct thermal_cooling_device *);
- int (*get_temp) (struct thermal_zone_device *, char *);
- int (*get_mode) (struct thermal_zone_device *, char *);
- int (*set_mode) (struct thermal_zone_device *, const char *);
- int (*get_trip_type) (struct thermal_zone_device *, int, char *);
- int (*get_trip_temp) (struct thermal_zone_device *, int, char *);
- int (*get_crit_temp) (struct thermal_zone_device *, unsigned long *);
+ int (*get_temp) (struct thermal_zone_device *, int *);
+ int (*get_mode) (struct thermal_zone_device *, enum thermal_mode_t *);
+ int (*set_mode) (struct thermal_zone_device *, enum thermal_mode_t);
+ int (*get_trip_type) (struct thermal_zone_device *, int,
+ enum thermal_trip_t *);
+ int (*get_trip_temp) (struct thermal_zone_device *, int,
+ int *);
+ int (*get_crit_temp) (struct thermal_zone_device *, int *);
};

struct thermal_cooling_device_ops {
- int (*get_max_state) (struct thermal_cooling_device *, char *);
- int (*get_cur_state) (struct thermal_cooling_device *, char *);
+ int (*get_max_state) (struct thermal_cooling_device *, unsigned int *);
+ int (*get_cur_state) (struct thermal_cooling_device *, unsigned int *);
int (*set_cur_state) (struct thermal_cooling_device *, unsigned int);
};

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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