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authorZhang Rui <rui.zhang@intel.com>2013-08-15 07:56:24 +0200
committerZhang Rui <rui.zhang@intel.com>2013-08-15 07:56:24 +0200
commit9c532d1710326c0f6f5d46d7f78d9da1a03b7a52 (patch)
tree75e1c0257e00cf55c1a01ab18fcf7b60c390076e /Documentation
parentMerge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 (diff)
parentDocumentation: thermal: Explain the exynos thermal driver model (diff)
downloadlinux-9c532d1710326c0f6f5d46d7f78d9da1a03b7a52.tar.xz
linux-9c532d1710326c0f6f5d46d7f78d9da1a03b7a52.zip
Merge branch 'for_3.12/exynos' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal into exynos
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/thermal/exynos-thermal.txt55
-rw-r--r--Documentation/thermal/exynos_thermal43
2 files changed, 89 insertions, 9 deletions
diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
new file mode 100644
index 000000000000..284f5300fd8b
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
@@ -0,0 +1,55 @@
+* Exynos Thermal Management Unit (TMU)
+
+** Required properties:
+
+- compatible : One of the following:
+ "samsung,exynos4412-tmu"
+ "samsung,exynos4210-tmu"
+ "samsung,exynos5250-tmu"
+ "samsung,exynos5440-tmu"
+- interrupt-parent : The phandle for the interrupt controller
+- reg : Address range of the thermal registers. For soc's which has multiple
+ instances of TMU and some registers are shared across all TMU's like
+ interrupt related then 2 set of register has to supplied. First set
+ belongs to each instance of TMU and second set belongs to common TMU
+ registers.
+- interrupts : Should contain interrupt for thermal system
+- clocks : The main clock for TMU device
+- clock-names : Thermal system clock name
+- vtmu-supply: This entry is optional and provides the regulator node supplying
+ voltage to TMU. If needed this entry can be placed inside
+ board/platform specific dts file.
+
+Example 1):
+
+ tmu@100C0000 {
+ compatible = "samsung,exynos4412-tmu";
+ interrupt-parent = <&combiner>;
+ reg = <0x100C0000 0x100>;
+ interrupts = <2 4>;
+ clocks = <&clock 383>;
+ clock-names = "tmu_apbif";
+ status = "disabled";
+ vtmu-supply = <&tmu_regulator_node>;
+ };
+
+Example 2):
+
+ tmuctrl_0: tmuctrl@160118 {
+ compatible = "samsung,exynos5440-tmu";
+ reg = <0x160118 0x230>, <0x160368 0x10>;
+ interrupts = <0 58 0>;
+ clocks = <&clock 21>;
+ clock-names = "tmu_apbif";
+ };
+
+Note: For multi-instance tmu each instance should have an alias correctly
+numbered in "aliases" node.
+
+Example:
+
+aliases {
+ tmuctrl0 = &tmuctrl_0;
+ tmuctrl1 = &tmuctrl_1;
+ tmuctrl2 = &tmuctrl_2;
+};
diff --git a/Documentation/thermal/exynos_thermal b/Documentation/thermal/exynos_thermal
index 2b46f67b1ccb..9010c4416967 100644
--- a/Documentation/thermal/exynos_thermal
+++ b/Documentation/thermal/exynos_thermal
@@ -1,17 +1,17 @@
-Kernel driver exynos4_tmu
+Kernel driver exynos_tmu
=================
Supported chips:
-* ARM SAMSUNG EXYNOS4 series of SoC
- Prefix: 'exynos4-tmu'
+* ARM SAMSUNG EXYNOS4, EXYNOS5 series of SoC
Datasheet: Not publicly available
Authors: Donggeun Kim <dg77.kim@samsung.com>
+Authors: Amit Daniel <amit.daniel@samsung.com>
-Description
------------
+TMU controller Description:
+---------------------------
-This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC.
+This driver allows to read temperature inside SAMSUNG EXYNOS4/5 series of SoC.
The chip only exposes the measured 8-bit temperature code value
through a register.
@@ -34,9 +34,9 @@ The three equations are:
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
+TMU(Thermal Management Unit) in EXYNOS4/5 generates interrupt
when temperature exceeds pre-defined levels.
-The maximum number of configurable threshold is four.
+The maximum number of configurable threshold is five.
The threshold levels are defined as follows:
Level_0: current temperature > trigger_level_0 + threshold
Level_1: current temperature > trigger_level_1 + threshold
@@ -47,6 +47,31 @@ The threshold levels are defined as follows:
through the corresponding registers.
When an interrupt occurs, this driver notify kernel thermal framework
-with the function exynos4_report_trigger.
+with the function exynos_report_trigger.
Although an interrupt condition for level_0 can be set,
it can be used to synchronize the cooling action.
+
+TMU driver description:
+-----------------------
+
+The exynos thermal driver is structured as,
+
+ Kernel Core thermal framework
+ (thermal_core.c, step_wise.c, cpu_cooling.c)
+ ^
+ |
+ |
+TMU configuration data -------> TMU Driver <------> Exynos Core thermal wrapper
+(exynos_tmu_data.c) (exynos_tmu.c) (exynos_thermal_common.c)
+(exynos_tmu_data.h) (exynos_tmu.h) (exynos_thermal_common.h)
+
+a) TMU configuration data: This consist of TMU register offsets/bitfields
+ described through structure exynos_tmu_registers. Also several
+ other platform data (struct exynos_tmu_platform_data) members
+ are used to configure the TMU.
+b) TMU driver: This component initialises the TMU controller and sets different
+ thresholds. It invokes core thermal implementation with the call
+ exynos_report_trigger.
+c) Exynos Core thermal wrapper: This provides 3 wrapper function to use the
+ Kernel core thermal framework. They are exynos_unregister_thermal,
+ exynos_register_thermal and exynos_report_trigger.