Re: [PATCHv4 5/9] Thermal: Add trip point sysfs nodes for sensor

From: Srinivas Pandruvada
Date: Wed Oct 30 2013 - 21:33:43 EST


You might want to use new DEVICE_ATTR_RO and DEVICE_ATTR_RW in this series. GKH wanted this changes in my powercap patchset.

Thanks,
Srinivas

On 10/15/2013 06:12 AM, R, Durgadoss wrote:
-----Original Message-----
From: Zhang, Rui
Sent: Tuesday, October 15, 2013 4:33 PM
To: R, Durgadoss
Cc: eduardo.valentin@xxxxxx; linux-pm@xxxxxxxxxxxxxxx; linux-
kernel@xxxxxxxxxxxxxxx; hongbo.zhang@xxxxxxxxxxxxx; wni@xxxxxxxxxx
Subject: Re: [PATCHv4 5/9] Thermal: Add trip point sysfs nodes for sensor

On Wed, 2013-10-02 at 00:08 +0530, Durgadoss R wrote:
This patch adds a trip point related sysfs nodes
for each sensor under a zone in /sys/class/thermal/zoneX/.
The nodes will be named, sensorX_trip_activeY,
sensorX_trip_passiveY, sensorX_trip_hot, sensorX_trip_critical
for active, passive, hot and critical trip points
respectively for sensorX.

Signed-off-by: Durgadoss R <durgadoss.r@xxxxxxxxx>
---
drivers/thermal/thermal_core.c | 344
+++++++++++++++++++++++++++++++++++++++-
include/linux/thermal.h | 40 ++++-
2 files changed, 379 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 3c4ef62..d6e29f6 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -494,6 +494,60 @@ static void thermal_zone_device_check(struct
work_struct *work)
thermal_zone_device_update(tz);
}

+static int get_sensor_indx_by_kobj(struct thermal_zone *tz, const char
*name)
+{
+ int i, indx = -EINVAL;
+
+ /* Protect against tz->sensors[i] being unregistered */
+ mutex_lock(&sensor_list_lock);
+
+ for (i = 0; i < tz->sensor_indx; i++) {
+ if (!strnicmp(name, kobject_name(&tz->sensors[i]-
device.kobj),
+ THERMAL_NAME_LENGTH)) {
+ indx = i;
+ break;
+ }
+ }
+
+ mutex_unlock(&sensor_list_lock);
+ return indx;
+}
+
+static void __remove_trip_attr(struct thermal_zone *tz, int indx)
+{
+ int i;
+ struct thermal_trip_attr *attr = tz->trip_attr[indx];
+ struct thermal_trip_point *trip = tz->sensor_trip[indx];
+
+ if (!attr || !trip)
+ return;
+
+ if (trip->crit != THERMAL_TRIPS_NONE)
+ device_remove_file(&tz->device, &attr->crit_attr.attr);
+
+ if (trip->hot != THERMAL_TRIPS_NONE)
+ device_remove_file(&tz->device, &attr->hot_attr.attr);
+
+ if (trip->num_passive_trips > 0) {
+ for (i = 0; i < trip->num_passive_trips; i++) {
+ device_remove_file(&tz->device,
+ &attr->passive_attrs[i].attr);
+ }
+ kfree(attr->passive_attrs);
+ }
+
+ if (trip->num_active_trips > 0) {
+ for (i = 0; i < trip->num_active_trips; i++) {
+ device_remove_file(&tz->device,
+ &attr->active_attrs[i].attr);
+ }
+ kfree(attr->active_attrs);
+ }
+
+ kfree(tz->trip_attr[indx]);
+ tz->trip_attr[indx] = NULL;
+}
+
static void remove_sensor_from_zone(struct thermal_zone *tz,
struct thermal_sensor *ts)
{
@@ -503,13 +557,19 @@ static void remove_sensor_from_zone(struct
thermal_zone *tz,
if (indx < 0)
return;

- sysfs_remove_link(&tz->device.kobj, kobject_name(&ts->device.kobj));
-
mutex_lock(&tz->lock);

+ /* Remove trip point attributes associated with this sensor */
+ __remove_trip_attr(tz, indx);
+
+ sysfs_remove_link(&tz->device.kobj, kobject_name(&ts->device.kobj));
+
/* Shift the entries in the tz->sensors array */
- for (j = indx; j < MAX_SENSORS_PER_ZONE - 1; j++)
+ for (j = indx; j < MAX_SENSORS_PER_ZONE - 1; j++) {
tz->sensors[j] = tz->sensors[j + 1];
+ tz->sensor_trip[j] = tz->sensor_trip[j + 1];
+ tz->trip_attr[j] = tz->trip_attr[j + 1];
+ }

tz->sensor_indx--;
mutex_unlock(&tz->lock);
@@ -952,6 +1012,111 @@ emul_temp_store(struct device *dev, struct
device_attribute *attr,
static DEVICE_ATTR(emul_temp, S_IWUSR, NULL, emul_temp_store);
#endif/*CONFIG_THERMAL_EMULATION*/

+static ssize_t
+active_trip_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ int i, j, val;
+ char kobj_name[THERMAL_NAME_LENGTH];
+ struct thermal_zone *tz = to_zone(dev);
+
+ if (!sscanf(attr->attr.name, "sensor%d_trip_active%d", &i, &j))
+ return -EINVAL;
+
+ snprintf(kobj_name, THERMAL_NAME_LENGTH, "sensor%d", i);
+
+ mutex_lock(&tz->lock);
+
+ i = get_sensor_indx_by_kobj(tz, kobj_name);
+ if (i < 0) {
+ mutex_unlock(&tz->lock);
+ return i;
+ }
+
+ val = tz->sensor_trip[i]->active_trips[j];
+ mutex_unlock(&tz->lock);
+
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t
+passive_trip_show(struct device *dev, struct device_attribute *attr, char
*buf)
+{
+ int i, j, val;
+ char kobj_name[THERMAL_NAME_LENGTH];
+ struct thermal_zone *tz = to_zone(dev);
+
+ if (!sscanf(attr->attr.name, "sensor%d_trip_passive%d", &i, &j))
+ return -EINVAL;
+
+ snprintf(kobj_name, THERMAL_NAME_LENGTH, "sensor%d", i);
+
+ mutex_lock(&tz->lock);
+
+ i = get_sensor_indx_by_kobj(tz, kobj_name);
+ if (i < 0) {
+ mutex_unlock(&tz->lock);
+ return i;
+ }
+
+ val = tz->sensor_trip[i]->passive_trips[j];
+ mutex_unlock(&tz->lock);
+
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t
+hot_trip_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ int indx, val;
+ char kobj_name[THERMAL_NAME_LENGTH];
+ struct thermal_zone *tz = to_zone(dev);
+
+ if (!sscanf(attr->attr.name, "sensor%d_trip_hot", &indx))
+ return -EINVAL;
+
+ snprintf(kobj_name, THERMAL_NAME_LENGTH, "sensor%d", indx);
+
+ mutex_lock(&tz->lock);
+
+ indx = get_sensor_indx_by_kobj(tz, kobj_name);
+ if (indx < 0) {
+ mutex_unlock(&tz->lock);
+ return indx;
+ }
+
+ val = tz->sensor_trip[indx]->hot;
+ mutex_unlock(&tz->lock);
+
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t
+critical_trip_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int indx, val;
+ char kobj_name[THERMAL_NAME_LENGTH];
+ struct thermal_zone *tz = to_zone(dev);
+
+ if (!sscanf(attr->attr.name, "sensor%d_trip_critical", &indx))
+ return -EINVAL;
+
+ snprintf(kobj_name, THERMAL_NAME_LENGTH, "sensor%d", indx);
+
+ mutex_lock(&tz->lock);
+
+ indx = get_sensor_indx_by_kobj(tz, kobj_name);
+ if (indx < 0) {
+ mutex_unlock(&tz->lock);
+ return indx;
+ }
+
+ val = tz->sensor_trip[indx]->crit;
+ mutex_unlock(&tz->lock);
+
+ return sprintf(buf, "%d\n", val);
+}
+
static DEVICE_ATTR(type, 0444, type_show, NULL);
static DEVICE_ATTR(temp, 0444, temp_show, NULL);
static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
@@ -962,7 +1127,8 @@ static DEVICE_ATTR(policy, S_IRUGO | S_IWUSR,
policy_show, policy_store);
static DEVICE_ATTR(sensor_name, 0444, sensor_name_show, NULL);
static DEVICE_ATTR(temp_input, 0444, sensor_temp_show, NULL);

-static DEVICE_ATTR(zone_name, 0444, zone_name_show, NULL);
+/* Thermal zone attributes */
+static DEVICE_ATTR(zone_name, S_IRUGO, zone_name_show, NULL);

/* sys I/F for cooling device */
#define to_cooling_device(_dev) \
@@ -1841,6 +2007,43 @@ static int enable_sensor_thresholds(struct
thermal_sensor *ts, int count)
return 0;
}

+static int create_single_trip_attr(struct thermal_zone *tz,
+ struct thermal_attr *attr,
+ const char *attr_name,
+ ssize_t (*rd_ptr)(struct device *dev,
+ struct device_attribute *devattr, char *buf))
+{
+ snprintf(attr->name, THERMAL_NAME_LENGTH, attr_name);
+ sysfs_attr_init(&attr->attr.attr);
+ attr->attr.attr.name = attr->name;
+ attr->attr.attr.mode = S_IRUGO;
+ attr->attr.show = rd_ptr;
+ return device_create_file(&tz->device, &attr->attr);
+}
+
+static int create_multi_trip_attrs(struct thermal_zone *tz, int size,
+ int indx, struct thermal_attr *attrs,
+ const char *attr_name,
+ ssize_t (*rd_ptr)(struct device *dev,
+ struct device_attribute *devattr, char *buf))
+{
+ char name[THERMAL_NAME_LENGTH];
+ int i, ret;
+
+ for (i = 0; i < size; i++) {
+ snprintf(name, THERMAL_NAME_LENGTH, attr_name, indx, i);
+ ret = create_single_trip_attr(tz, &attrs[i], name, rd_ptr);
+ if (ret)
+ goto exit;
+ }
+ return 0;
+
+exit:
+ while (--i >= 0)
+ device_remove_file(&tz->device, &attrs[i].attr);
+ return ret;
+}
+
/**
* create_thermal_zone - create sysfs nodes for thermal zone
* @name: Name of the thermla zone
@@ -2139,6 +2342,139 @@ exit_zone:
EXPORT_SYMBOL(add_cdev_to_zone);

/**
+ * add_sensor_trip_info - Add trip point information for @ts in @tz
+ * @tz: Thermal zone reference
+ * @ts: Thermal sensor reference
+ * @trip: Trip point structure reference
+ *
+ * Returns 0 on success, otherwise
+ * -EINVAL for invalid paramenters
+ * -EINVAL if @ts is not part of 'this' thermal zone @tz
+ * -ENOMEM on kzalloc failures
+ */
+int add_sensor_trip_info(struct thermal_zone *tz, struct thermal_sensor *ts,
+ struct thermal_trip_point *trip)
+{
+ char name[THERMAL_NAME_LENGTH];
+ int i, indx, kobj_indx, ret, size;
+ struct thermal_trip_attr *attrs;
+
+ if (!tz || !ts || !trip)
+ return -EINVAL;
+
+ if (!sscanf(kobject_name(&ts->device.kobj), "sensor%d", &kobj_indx))
+ return -EINVAL;
+
+ mutex_lock(&zone_list_lock);
+
+ indx = GET_INDEX(tz, ts, sensor);
+ if (indx < 0) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ /* Protect against 'ts' being unregistered */
+ mutex_lock(&sensor_list_lock);
+
+ /* Protect tz->trip_attr[] and tz->sensor_trip[] */
+ mutex_lock(&tz->lock);
+
+ tz->trip_attr[indx] = kzalloc(sizeof(struct thermal_trip_attr),
+ GFP_KERNEL);
+ if (!tz->trip_attr[indx]) {
+ ret = -ENOMEM;
+ goto exit_lock;
+ }
+
+ attrs = tz->trip_attr[indx];
+
+ /* Create Critical trip point attribute */
+ if (trip->crit != THERMAL_TRIPS_NONE) {
+ snprintf(name, THERMAL_NAME_LENGTH,
+ "sensor%d_trip_critical", kobj_indx);
+ ret = create_single_trip_attr(tz, &attrs->crit_attr,
+ name, critical_trip_show);
+ if (ret)
+ goto exit_trip;
+ }
+
+ /* Create Hot trip point attribute */
+ if (trip->hot != THERMAL_TRIPS_NONE) {
+ snprintf(name, THERMAL_NAME_LENGTH,
+ "sensor%d_trip_hot", kobj_indx);
+ ret = create_single_trip_attr(tz, &attrs->hot_attr,
+ name, hot_trip_show);
+ if (ret)
+ goto exit_crit_trip;
+ }
+
+ /* Create Passive trip point attributes */
+ if (trip->num_passive_trips > 0) {
+ size = sizeof(struct thermal_attr) * trip->num_passive_trips;
+ attrs->passive_attrs = kzalloc(size, GFP_KERNEL);
+ if (!attrs->passive_attrs) {
+ ret = -ENOMEM;
+ goto exit_hot_trip;
+ }
+
+ ret = create_multi_trip_attrs(tz, trip->num_passive_trips,
+ kobj_indx, attrs->passive_attrs,
+ "sensor%d_trip_passive%d",
well, I do not think this is a good code style.
I prefer to create the attrs one by one, rather than passing this ugly
format string.
please use create_single_trip_attr() instead if you can not find a clean
way to do this.
Okay, Will change in next revision.

Thanks,
Durga

thanks,
rui
+ passive_trip_show);
+ if (ret)
+ goto exit_hot_trip;
+ }
+
+ /* Create Active trip point attributes */
+ if (trip->num_active_trips > 0) {
+ size = sizeof(struct thermal_attr) * trip->num_active_trips;
+ attrs->active_attrs = kzalloc(size, GFP_KERNEL);
+ if (!attrs->active_attrs) {
+ ret = -ENOMEM;
+ goto exit_passive_trips;
+ }
+
+ ret = create_multi_trip_attrs(tz, trip->num_active_trips,
+ kobj_indx, attrs->active_attrs,
+ "sensor%d_trip_active%d",
+ active_trip_show);
+ if (ret)
+ goto exit_passive_trips;
+ }
+
+ tz->sensor_trip[indx] = trip;
+
+ mutex_unlock(&tz->lock);
+ mutex_unlock(&sensor_list_lock);
+ mutex_unlock(&zone_list_lock);
+
+ return 0;
+
+exit_passive_trips:
+ kfree(attrs->active_attrs);
+ i = trip->num_passive_trips;
+ while (--i >= 0)
+ device_remove_file(&tz->device, &attrs->passive_attrs[i].attr);
+exit_hot_trip:
+ kfree(attrs->passive_attrs);
+ if (trip->hot != THERMAL_TRIPS_NONE)
+ device_remove_file(&tz->device, &attrs->hot_attr.attr);
+exit_crit_trip:
+ if (trip->crit != THERMAL_TRIPS_NONE)
+ device_remove_file(&tz->device, &attrs->crit_attr.attr);
+exit_trip:
+ kfree(tz->trip_attr[indx]);
+ tz->trip_attr[indx] = NULL;
+exit_lock:
+ mutex_unlock(&tz->lock);
+ mutex_unlock(&sensor_list_lock);
+exit:
+ mutex_unlock(&zone_list_lock);
+ return ret;
+}
+EXPORT_SYMBOL(add_sensor_trip_info);
+
+/**
* thermal_sensor_register - register a new thermal sensor
* @name: name of the thermal sensor
* @count: Number of thresholds supported by hardware
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index da7520c..f8de86d 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -31,7 +31,7 @@

#define THERMAL_TRIPS_NONE -1
#define THERMAL_MAX_TRIPS 12
-#define THERMAL_NAME_LENGTH 20
+#define THERMAL_NAME_LENGTH 25

/* invalid cooling state */
#define THERMAL_CSTATE_INVALID -1UL
@@ -170,6 +170,37 @@ struct thermal_attr {
char name[THERMAL_NAME_LENGTH];
};

+/*
+ * This structure defines the trip points for a sensor.
+ * The actual values for these trip points come from
+ * platform characterization. The thermal governors
+ * (either kernel or user space) may take appropriate
+ * actions when the sensors reach these trip points.
+ * See Documentation/thermal/sysfs-api2.txt for more details.
+ *
+ * As of now, For a particular sensor, we support:
+ * a) 1 hot trip point
+ * b) 1 critical trip point
+ * c) 'n' passive trip points
+ * d) 'm' active trip points
+ */
+struct thermal_trip_point {
+ int hot;
+ int crit;
+ int num_passive_trips;
+ int *passive_trips;
+ int num_active_trips;
+ int *active_trips;
+ int active_trip_mask;
+};
+
+struct thermal_trip_attr {
+ struct thermal_attr hot_attr;
+ struct thermal_attr crit_attr;
+ struct thermal_attr *active_attrs;
+ struct thermal_attr *passive_attrs;
+};
+
struct thermal_sensor {
char name[THERMAL_NAME_LENGTH];
int id;
@@ -229,6 +260,10 @@ struct thermal_zone {
/* cdev level information */
int cdev_indx; /* index into 'cdevs' array */
struct thermal_cooling_device *cdevs[MAX_CDEVS_PER_ZONE];
+
+ /* Thermal sensors trip information */
+ struct thermal_trip_point *sensor_trip[MAX_SENSORS_PER_ZONE];
+ struct thermal_trip_attr *trip_attr[MAX_SENSORS_PER_ZONE];
};

/* Structure that holds thermal governor information */
@@ -309,6 +344,9 @@ struct thermal_sensor *get_sensor_by_name(const
char *);
int add_cdev_to_zone(struct thermal_zone *, struct thermal_cooling_device
*);
struct thermal_cooling_device *get_cdev_by_name(const char *);

+int add_sensor_trip_info(struct thermal_zone *, struct thermal_sensor *,
+ struct thermal_trip_point *);
+
#ifdef CONFIG_NET
extern int thermal_generate_netlink_event(struct thermal_zone_device *tz,
enum events event);
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