diff options
author | Amit Daniel Kachhap <amit.daniel@samsung.com> | 2013-06-24 06:50:49 -0400 |
---|---|---|
committer | Eduardo Valentin <eduardo.valentin@ti.com> | 2013-08-13 09:52:04 -0400 |
commit | beb70b2d2fe211fc98ec13cf769f331243f5221a (patch) | |
tree | 09aa7c86dd65b6d37dfe1fc473064936f09a3a11 /Documentation/thermal | |
parent | 0e97194bcfa09fc835016e3aa12b932827a9e2a6 (diff) |
Documentation: thermal: Explain the exynos thermal driver model
This patch updates the documentation to explain the driver model
and file layout.
Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
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 @@ | |||
1 | Kernel driver exynos4_tmu | 1 | Kernel driver exynos_tmu |
2 | ================= | 2 | ================= |
3 | 3 | ||
4 | Supported chips: | 4 | Supported chips: |
5 | * ARM SAMSUNG EXYNOS4 series of SoC | 5 | * ARM SAMSUNG EXYNOS4, EXYNOS5 series of SoC |
6 | Prefix: 'exynos4-tmu' | ||
7 | Datasheet: Not publicly available | 6 | Datasheet: Not publicly available |
8 | 7 | ||
9 | Authors: Donggeun Kim <dg77.kim@samsung.com> | 8 | Authors: Donggeun Kim <dg77.kim@samsung.com> |
9 | Authors: Amit Daniel <amit.daniel@samsung.com> | ||
10 | 10 | ||
11 | Description | 11 | TMU controller Description: |
12 | ----------- | 12 | --------------------------- |
13 | 13 | ||
14 | This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC. | 14 | This driver allows to read temperature inside SAMSUNG EXYNOS4/5 series of SoC. |
15 | 15 | ||
16 | The chip only exposes the measured 8-bit temperature code value | 16 | The chip only exposes the measured 8-bit temperature code value |
17 | through a register. | 17 | through a register. |
@@ -34,9 +34,9 @@ The three equations are: | |||
34 | TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register) | 34 | TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register) |
35 | Temperature code measured at 85 degree Celsius which is unchanged | 35 | Temperature code measured at 85 degree Celsius which is unchanged |
36 | 36 | ||
37 | TMU(Thermal Management Unit) in EXYNOS4 generates interrupt | 37 | TMU(Thermal Management Unit) in EXYNOS4/5 generates interrupt |
38 | when temperature exceeds pre-defined levels. | 38 | when temperature exceeds pre-defined levels. |
39 | The maximum number of configurable threshold is four. | 39 | The maximum number of configurable threshold is five. |
40 | The threshold levels are defined as follows: | 40 | The threshold levels are defined as follows: |
41 | Level_0: current temperature > trigger_level_0 + threshold | 41 | Level_0: current temperature > trigger_level_0 + threshold |
42 | Level_1: current temperature > trigger_level_1 + threshold | 42 | Level_1: current temperature > trigger_level_1 + threshold |
@@ -47,6 +47,31 @@ The threshold levels are defined as follows: | |||
47 | through the corresponding registers. | 47 | through the corresponding registers. |
48 | 48 | ||
49 | When an interrupt occurs, this driver notify kernel thermal framework | 49 | When an interrupt occurs, this driver notify kernel thermal framework |
50 | with the function exynos4_report_trigger. | 50 | with the function exynos_report_trigger. |
51 | Although an interrupt condition for level_0 can be set, | 51 | Although an interrupt condition for level_0 can be set, |
52 | it can be used to synchronize the cooling action. | 52 | it can be used to synchronize the cooling action. |
53 | |||
54 | TMU driver description: | ||
55 | ----------------------- | ||
56 | |||
57 | The exynos thermal driver is structured as, | ||
58 | |||
59 | Kernel Core thermal framework | ||
60 | (thermal_core.c, step_wise.c, cpu_cooling.c) | ||
61 | ^ | ||
62 | | | ||
63 | | | ||
64 | TMU configuration data -------> TMU Driver <------> Exynos Core thermal wrapper | ||
65 | (exynos_tmu_data.c) (exynos_tmu.c) (exynos_thermal_common.c) | ||
66 | (exynos_tmu_data.h) (exynos_tmu.h) (exynos_thermal_common.h) | ||
67 | |||
68 | a) TMU configuration data: This consist of TMU register offsets/bitfields | ||
69 | described through structure exynos_tmu_registers. Also several | ||
70 | other platform data (struct exynos_tmu_platform_data) members | ||
71 | are used to configure the TMU. | ||
72 | b) TMU driver: This component initialises the TMU controller and sets different | ||
73 | thresholds. It invokes core thermal implementation with the call | ||
74 | exynos_report_trigger. | ||
75 | c) Exynos Core thermal wrapper: This provides 3 wrapper function to use the | ||
76 | Kernel core thermal framework. They are exynos_unregister_thermal, | ||
77 | exynos_register_thermal and exynos_report_trigger. | ||