From 27365a6c7d64a3bba22ee62109e4a071bbd7f933 Mon Sep 17 00:00:00 2001 From: Durgadoss R Date: Wed, 25 Jul 2012 10:10:59 +0800 Subject: [PATCH] Thermal: Add Hysteresis attributes The Linux Thermal Framework does not support hysteresis attributes. Most thermal sensors, today, have a hysteresis value associated with trip points. This patch adds hysteresis attributes on a per-trip-point basis, to the Thermal Framework. These attributes are optionally writable. Signed-off-by: Durgadoss R Signed-off-by: Zhang Rui Signed-off-by: Len Brown --- Documentation/thermal/sysfs-api.txt | 6 ++ drivers/thermal/thermal_sys.c | 88 +++++++++++++++++++++++++++-- include/linux/thermal.h | 5 ++ 3 files changed, 94 insertions(+), 5 deletions(-) diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index 4c105934c599..2ba4c9bb790a 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -121,6 +121,7 @@ Thermal zone device sys I/F, created once it's registered: |---mode: Working mode of the thermal zone |---trip_point_[0-*]_temp: Trip point temperature |---trip_point_[0-*]_type: Trip point type + |---trip_point_[0-*]_hyst: Hysteresis value for this trip point Thermal cooling device sys I/F, created once it's registered: /sys/class/thermal/cooling_device[0-*]: @@ -190,6 +191,11 @@ trip_point_[0-*]_type thermal zone. RO, Optional +trip_point_[0-*]_hyst + The hysteresis value for a trip point, represented as an integer + Unit: Celsius + RW, Optional + cdev[0-*] Sysfs link to the thermal cooling device node where the sys I/F for cooling device throttling control represents. diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c index 5feb3353213f..2d7a9fe8f365 100644 --- a/drivers/thermal/thermal_sys.c +++ b/drivers/thermal/thermal_sys.c @@ -239,6 +239,52 @@ trip_point_temp_show(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%ld\n", temperature); } +static ssize_t +trip_point_hyst_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct thermal_zone_device *tz = to_thermal_zone(dev); + int trip, ret; + unsigned long temperature; + + if (!tz->ops->set_trip_hyst) + return -EPERM; + + if (!sscanf(attr->attr.name, "trip_point_%d_hyst", &trip)) + return -EINVAL; + + if (kstrtoul(buf, 10, &temperature)) + return -EINVAL; + + /* + * We are not doing any check on the 'temperature' value + * here. The driver implementing 'set_trip_hyst' has to + * take care of this. + */ + ret = tz->ops->set_trip_hyst(tz, trip, temperature); + + return ret ? ret : count; +} + +static ssize_t +trip_point_hyst_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct thermal_zone_device *tz = to_thermal_zone(dev); + int trip, ret; + unsigned long temperature; + + if (!tz->ops->get_trip_hyst) + return -EPERM; + + if (!sscanf(attr->attr.name, "trip_point_%d_hyst", &trip)) + return -EINVAL; + + ret = tz->ops->get_trip_hyst(tz, trip, &temperature); + + return ret ? ret : sprintf(buf, "%ld\n", temperature); +} + static ssize_t passive_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -1091,21 +1137,29 @@ EXPORT_SYMBOL(thermal_zone_device_update); static int create_trip_attrs(struct thermal_zone_device *tz, int mask) { int indx; + int size = sizeof(struct thermal_attr) * tz->trips; - tz->trip_type_attrs = - kzalloc(sizeof(struct thermal_attr) * tz->trips, GFP_KERNEL); + tz->trip_type_attrs = kzalloc(size, GFP_KERNEL); if (!tz->trip_type_attrs) return -ENOMEM; - tz->trip_temp_attrs = - kzalloc(sizeof(struct thermal_attr) * tz->trips, GFP_KERNEL); + tz->trip_temp_attrs = kzalloc(size, GFP_KERNEL); if (!tz->trip_temp_attrs) { kfree(tz->trip_type_attrs); return -ENOMEM; } - for (indx = 0; indx < tz->trips; indx++) { + if (tz->ops->get_trip_hyst) { + tz->trip_hyst_attrs = kzalloc(size, GFP_KERNEL); + if (!tz->trip_hyst_attrs) { + kfree(tz->trip_type_attrs); + kfree(tz->trip_temp_attrs); + return -ENOMEM; + } + } + + for (indx = 0; indx < tz->trips; indx++) { /* create trip type attribute */ snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH, "trip_point_%d_type", indx); @@ -1136,6 +1190,26 @@ static int create_trip_attrs(struct thermal_zone_device *tz, int mask) device_create_file(&tz->device, &tz->trip_temp_attrs[indx].attr); + + /* create Optional trip hyst attribute */ + if (!tz->ops->get_trip_hyst) + continue; + snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH, + "trip_point_%d_hyst", indx); + + sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr); + tz->trip_hyst_attrs[indx].attr.attr.name = + tz->trip_hyst_attrs[indx].name; + tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO; + tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show; + if (tz->ops->set_trip_hyst) { + tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR; + tz->trip_hyst_attrs[indx].attr.store = + trip_point_hyst_store; + } + + device_create_file(&tz->device, + &tz->trip_hyst_attrs[indx].attr); } return 0; } @@ -1149,9 +1223,13 @@ static void remove_trip_attrs(struct thermal_zone_device *tz) &tz->trip_type_attrs[indx].attr); device_remove_file(&tz->device, &tz->trip_temp_attrs[indx].attr); + if (tz->ops->get_trip_hyst) + device_remove_file(&tz->device, + &tz->trip_hyst_attrs[indx].attr); } kfree(tz->trip_type_attrs); kfree(tz->trip_temp_attrs); + kfree(tz->trip_hyst_attrs); } /** diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 6eaf9146c847..cfc8d908892e 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -60,6 +60,10 @@ struct thermal_zone_device_ops { unsigned long *); int (*set_trip_temp) (struct thermal_zone_device *, int, unsigned long); + int (*get_trip_hyst) (struct thermal_zone_device *, int, + unsigned long *); + int (*set_trip_hyst) (struct thermal_zone_device *, int, + unsigned long); int (*get_crit_temp) (struct thermal_zone_device *, unsigned long *); int (*notify) (struct thermal_zone_device *, int, enum thermal_trip_type); @@ -98,6 +102,7 @@ struct thermal_zone_device { struct device device; struct thermal_attr *trip_temp_attrs; struct thermal_attr *trip_type_attrs; + struct thermal_attr *trip_hyst_attrs; void *devdata; int trips; int tc1;