diff options
Diffstat (limited to 'Documentation/thermal')
| -rw-r--r-- | Documentation/thermal/exynos_thermal | 43 |
1 files changed, 34 insertions, 9 deletions
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. |