[PATCH V2 0/6] thermal: exynos: Add kernel thermal support for exynos platform

Amit Daniel Kachhap amit.kachhap at linaro.org
Mon Mar 19 06:17:38 UTC 2012

Changes since V1:
*Moved the sensor driver to driver/thermal folder from driver/hwmon folder
 as suggested by Mark Brown and Guenter Roeck 
*Added notifier support to notify the registered drivers of any cpu cooling
 action. The driver can modify the default cooling behaviour(eg set different
 max clip frequency).
*The percentage based frequency replaced with absolute clipped frequency.
*Some more conditional checks when setting max frequency.
*Renamed the new trip type THERMAL_TRIP_STATE_ACTIVE to
*Many review comments from R, Durgadoss <durgadoss.r at intel.com> and 
 eduardo.valentin at ti.com implemented.
*Removed cooling stats through debugfs patch
*The V1 based can be found here,

Changes since RFC:
*Changed the cpu cooling registration/unregistration API's to instance based
*Changed the STATE_ACTIVE trip type to pass correct instance id
*Adding support to restore back the policy->max_freq after doing frequency 
*Moved the trip cooling stats from sysfs node to debugfs node as suggested
  by Greg KH greg at kroah.com 
*Incorporated several review comments from eduardo.valentin at ti.com
*Moved the Temperature sensor driver from driver/hwmon/ to driver/mfd
 as discussed with Guenter Roeck <guenter.roeck at ericsson.com> and 
 Donggeun Kim <dg77.kim at samsung.com> (https://lkml.org/lkml/2012/1/5/7)
*Some changes according to the changes in common cpu cooling APIs
*The RFC based patches can be found here,

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
codes is architecture independent.

2) This patchset adds a new trip type THERMAL_TRIP_STATE_INSTANCE which passes
cooling device instance number and may be helpful for cpufreq cooling devices
to take the correct cooling action. This trip type avoids the temperature
comparision check again inside the cooling handler.

3) This patchset adds generic cpu cooling low level implementation through
frequency clipping and cpu hotplug. 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 freq_clip_table *tab_ptr, unsigned int tab_size,
	const struct cpumask *mask_val)
   b)void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)

4) 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.

All this patchset is based on Kernel version 3.3-rc7 

A simple data/control flow diagrams is shown below,

Core Linux thermal <----->  Exynos thermal interface <----- Temperature Sensor
	  |                             |
	 \|/                            |
  Cpufreq cooling device <---------------

Amit Daniel Kachhap (6):
  thermal: Add a new trip type to use cooling device instance number
  thermal: Add generic cpufreq cooling implementation
  thermal: Add generic cpuhotplug cooling implementation
  hwmon: exynos4: Move thermal sensor driver to driver/thermal
  thermal: exynos4: Register the tmu sensor with the kernel thermal
  ARM: exynos4: Add thermal sensor driver platform device support

 Documentation/hwmon/exynos4_tmu           |   81 ---
 Documentation/thermal/cpu-cooling-api.txt |   76 +++
 Documentation/thermal/exynos4_tmu         |   52 ++
 Documentation/thermal/sysfs-api.txt       |    4 +-
 arch/arm/mach-exynos/Kconfig              |   11 +
 arch/arm/mach-exynos/Makefile             |    1 +
 arch/arm/mach-exynos/clock.c              |    4 +
 arch/arm/mach-exynos/dev-tmu.c            |   39 ++
 arch/arm/mach-exynos/include/mach/irqs.h  |    2 +
 arch/arm/mach-exynos/include/mach/map.h   |    1 +
 arch/arm/mach-exynos/mach-origen.c        |    1 +
 arch/arm/plat-samsung/include/plat/devs.h |    1 +
 drivers/hwmon/Kconfig                     |   10 -
 drivers/hwmon/Makefile                    |    1 -
 drivers/hwmon/exynos4_tmu.c               |  514 -------------------
 drivers/thermal/Kconfig                   |   21 +
 drivers/thermal/Makefile                  |    2 +
 drivers/thermal/cpu_cooling.c             |  529 +++++++++++++++++++
 drivers/thermal/exynos4_thermal.c         |  790 +++++++++++++++++++++++++++++
 drivers/thermal/thermal_sys.c             |   45 ++-
 include/linux/cpu_cooling.h               |   78 +++
 include/linux/platform_data/exynos4_tmu.h |    7 +
 include/linux/thermal.h                   |    1 +
 23 files changed, 1660 insertions(+), 611 deletions(-)
 delete mode 100644 Documentation/hwmon/exynos4_tmu
 create mode 100644 Documentation/thermal/cpu-cooling-api.txt
 create mode 100644 Documentation/thermal/exynos4_tmu
 create mode 100644 arch/arm/mach-exynos/dev-tmu.c
 delete mode 100644 drivers/hwmon/exynos4_tmu.c
 create mode 100644 drivers/thermal/cpu_cooling.c
 create mode 100644 drivers/thermal/exynos4_thermal.c
 create mode 100644 include/linux/cpu_cooling.h

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