From 9d99842f99d847191ebd0c28469d2c70fcc5bf9e Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Tue, 26 Jun 2012 16:35:57 +0800 Subject: Thermal: set upper and lower limits set upper and lower limits when binding a thermal cooling device to a thermal zone device. Signed-off-by: Zhang Rui Reviewed-by: Rafael J. Wysocki Reviewed-by: Eduardo Valentin --- Documentation/thermal/sysfs-api.txt | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt index c087dbc..ca1a1a3 100644 --- a/Documentation/thermal/sysfs-api.txt +++ b/Documentation/thermal/sysfs-api.txt @@ -84,7 +84,8 @@ temperature) and throttle appropriate devices. 1.3 interface for binding a thermal zone device with a thermal cooling device 1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, - int trip, struct thermal_cooling_device *cdev); + int trip, struct thermal_cooling_device *cdev, + unsigned long upper, unsigned long lower); This interface function bind a thermal cooling device to the certain trip point of a thermal zone device. @@ -93,6 +94,12 @@ temperature) and throttle appropriate devices. cdev: thermal cooling device trip: indicates which trip point the cooling devices is associated with in this thermal zone. + upper:the Maximum cooling state for this trip point. + THERMAL_NO_LIMIT means no upper limit, + and the cooling device can be in max_state. + lower:the Minimum cooling state can be used for this trip point. + THERMAL_NO_LIMIT means no lower limit, + and the cooling device can be in cooling state 0. 1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, int trip, struct thermal_cooling_device *cdev); -- cgit v1.1 From 023614183768a7ac62898bded5ec6c0c9fecbdd9 Mon Sep 17 00:00:00 2001 From: Amit Daniel Kachhap Date: Thu, 16 Aug 2012 17:11:40 +0530 Subject: thermal: add generic cpufreq cooling implementation This patchset introduces a new generic cooling device based on cpufreq that can be used on non-ACPI platforms. As a proof of concept, we have drivers for the following platforms using this mechanism now: * Samsung Exynos (Exynos4 and Exynos5) in the current patchset. * Freescale i.MX (git://git.linaro.org/people/amitdanielk/linux.git imx6q_thermal) There is a small change in cpufreq cooling registration APIs, so a minor change is needed for Freescale platforms. Brief Description: 1) The generic cooling devices code is placed inside driver/thermal/* as placing inside acpi folder will need un-necessary enabling of acpi code. This code is architecture independent. 2) This patchset adds generic cpu cooling low level implementation through frequency clipping. In future, other cpu related cooling devices may be added here. An ACPI version of this already exists (drivers/acpi/processor_thermal.c) .But this will be useful for platforms like ARM using the generic thermal interface along with the generic cpu cooling devices. The cooling device registration API's return cooling device pointers which can be easily binded with the thermal zone trip points. The important APIs exposed are, a) struct thermal_cooling_device *cpufreq_cooling_register( struct cpumask *clip_cpus) b) void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) 3) Samsung exynos platform thermal implementation is done using the generic cpu cooling APIs and the new trip type. The temperature sensor driver present in the hwmon folder(registered as hwmon driver) is moved to thermal folder and registered as a thermal driver. A simple data/control flow diagrams is shown below, Core Linux thermal <-----> Exynos thermal interface <----- Temperature Sensor | | \|/ | Cpufreq cooling device <--------------- TODO: *Will send the DT enablement patches later after the driver is merged. This patch: Add support for generic cpu thermal cooling low level implementations using frequency scaling up/down based on the registration parameters. Different cpu related cooling devices can be registered by the user and the binding of these cooling devices to the corresponding trip points can be easily done as the registration APIs return the cooling device pointer. The user of these APIs are responsible for passing clipping frequency . The drivers can also register to recieve notification about any cooling action called. [akpm@linux-foundation.org: fix comment layout] Signed-off-by: Amit Daniel Kachhap Cc: Guenter Roeck Cc: SangWook Ju Cc: Durgadoss Cc: Len Brown Cc: Jean Delvare Cc: Kyungmin Park Cc: Kukjin Kim Signed-off-by: Andrew Morton Signed-off-by: Amit Daniel Kachhap Signed-off-by: Zhang Rui --- Documentation/thermal/cpu-cooling-api.txt | 32 +++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 Documentation/thermal/cpu-cooling-api.txt (limited to 'Documentation') diff --git a/Documentation/thermal/cpu-cooling-api.txt b/Documentation/thermal/cpu-cooling-api.txt new file mode 100644 index 0000000..fca24c9 --- /dev/null +++ b/Documentation/thermal/cpu-cooling-api.txt @@ -0,0 +1,32 @@ +CPU cooling APIs How To +=================================== + +Written by Amit Daniel Kachhap + +Updated: 12 May 2012 + +Copyright (c) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) + +0. Introduction + +The generic cpu cooling(freq clipping) provides registration/unregistration APIs +to the caller. The binding of the cooling devices to the trip point is left for +the user. The registration APIs returns the cooling device pointer. + +1. cpu cooling APIs + +1.1 cpufreq registration/unregistration APIs +1.1.1 struct thermal_cooling_device *cpufreq_cooling_register( + struct cpumask *clip_cpus) + + This interface function registers the cpufreq cooling device with the name + "thermal-cpufreq-%x". This api can support multiple instances of cpufreq + cooling devices. + + clip_cpus: cpumask of cpus where the frequency constraints will happen. + +1.1.2 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) + + This interface function unregisters the "thermal-cpufreq-%x" cooling device. + + cdev: Cooling device pointer which has to be unregistered. -- cgit v1.1 From c48cbba6fee3587bdfe77ef850a1a0aa30a2a60f Mon Sep 17 00:00:00 2001 From: Amit Daniel Kachhap Date: Thu, 16 Aug 2012 17:11:41 +0530 Subject: hwmon: exynos4: move thermal sensor driver to driver/thermal directory This movement is needed because the hwmon entries and corresponding sysfs interface is a duplicate of utilities already provided by driver/thermal/thermal_sys.c. The goal is to place it in thermal folder and add necessary functions to use the in-kernel thermal interfaces. Signed-off-by: Amit Daniel Kachhap Acked-by: Guenter Roeck Cc: SangWook Ju Cc: Durgadoss Cc: Len Brown Cc: Jean Delvare Cc: Kyungmin Park Cc: Kukjin Kim Signed-off-by: Andrew Morton Signed-off-by: Amit Daniel Kachhap Signed-off-by: Zhang Rui --- Documentation/hwmon/exynos4_tmu | 81 ------------------------------------ Documentation/thermal/exynos_thermal | 52 +++++++++++++++++++++++ 2 files changed, 52 insertions(+), 81 deletions(-) delete mode 100644 Documentation/hwmon/exynos4_tmu create mode 100644 Documentation/thermal/exynos_thermal (limited to 'Documentation') diff --git a/Documentation/hwmon/exynos4_tmu b/Documentation/hwmon/exynos4_tmu deleted file mode 100644 index c3c6b41..0000000 --- a/Documentation/hwmon/exynos4_tmu +++ /dev/null @@ -1,81 +0,0 @@ -Kernel driver exynos4_tmu -================= - -Supported chips: -* ARM SAMSUNG EXYNOS4 series of SoC - Prefix: 'exynos4-tmu' - Datasheet: Not publicly available - -Authors: Donggeun Kim - -Description ------------ - -This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC. - -The chip only exposes the measured 8-bit temperature code value -through a register. -Temperature can be taken from the temperature code. -There are three equations converting from temperature to temperature code. - -The three equations are: - 1. Two point trimming - Tc = (T - 25) * (TI2 - TI1) / (85 - 25) + TI1 - - 2. One point trimming - Tc = T + TI1 - 25 - - 3. No trimming - Tc = T + 50 - - Tc: Temperature code, T: Temperature, - TI1: Trimming info for 25 degree Celsius (stored at TRIMINFO register) - Temperature code measured at 25 degree Celsius which is unchanged - TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register) - Temperature code measured at 85 degree Celsius which is unchanged - -TMU(Thermal Management Unit) in EXYNOS4 generates interrupt -when temperature exceeds pre-defined levels. -The maximum number of configurable threshold is four. -The threshold levels are defined as follows: - Level_0: current temperature > trigger_level_0 + threshold - Level_1: current temperature > trigger_level_1 + threshold - Level_2: current temperature > trigger_level_2 + threshold - Level_3: current temperature > trigger_level_3 + threshold - - The threshold and each trigger_level are set - through the corresponding registers. - -When an interrupt occurs, this driver notify user space of -one of four threshold levels for the interrupt -through kobject_uevent_env and sysfs_notify functions. -Although an interrupt condition for level_0 can be set, -it is not notified to user space through sysfs_notify function. - -Sysfs Interface ---------------- -name name of the temperature sensor - RO - -temp1_input temperature - RO - -temp1_max temperature for level_1 interrupt - RO - -temp1_crit temperature for level_2 interrupt - RO - -temp1_emergency temperature for level_3 interrupt - RO - -temp1_max_alarm alarm for level_1 interrupt - RO - -temp1_crit_alarm - alarm for level_2 interrupt - RO - -temp1_emergency_alarm - alarm for level_3 interrupt - RO diff --git a/Documentation/thermal/exynos_thermal b/Documentation/thermal/exynos_thermal new file mode 100644 index 0000000..2b46f67 --- /dev/null +++ b/Documentation/thermal/exynos_thermal @@ -0,0 +1,52 @@ +Kernel driver exynos4_tmu +================= + +Supported chips: +* ARM SAMSUNG EXYNOS4 series of SoC + Prefix: 'exynos4-tmu' + Datasheet: Not publicly available + +Authors: Donggeun Kim + +Description +----------- + +This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC. + +The chip only exposes the measured 8-bit temperature code value +through a register. +Temperature can be taken from the temperature code. +There are three equations converting from temperature to temperature code. + +The three equations are: + 1. Two point trimming + Tc = (T - 25) * (TI2 - TI1) / (85 - 25) + TI1 + + 2. One point trimming + Tc = T + TI1 - 25 + + 3. No trimming + Tc = T + 50 + + Tc: Temperature code, T: Temperature, + TI1: Trimming info for 25 degree Celsius (stored at TRIMINFO register) + Temperature code measured at 25 degree Celsius which is unchanged + TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register) + Temperature code measured at 85 degree Celsius which is unchanged + +TMU(Thermal Management Unit) in EXYNOS4 generates interrupt +when temperature exceeds pre-defined levels. +The maximum number of configurable threshold is four. +The threshold levels are defined as follows: + Level_0: current temperature > trigger_level_0 + threshold + Level_1: current temperature > trigger_level_1 + threshold + Level_2: current temperature > trigger_level_2 + threshold + Level_3: current temperature > trigger_level_3 + threshold + + The threshold and each trigger_level are set + through the corresponding registers. + +When an interrupt occurs, this driver notify kernel thermal framework +with the function exynos4_report_trigger. +Although an interrupt condition for level_0 can be set, +it can be used to synchronize the cooling action. -- cgit v1.1