[RFC PATCH v5 0/4] ARM: OMAP2+: AM33XX: Add suspend-resume support

[Dave Gerlach]

Tony,
On 01/20/2015 12:03 PM, Tony Lindgren wrote:
> * Dave Gerlach <d-gerlach at ti.com> [141126 13:54]:
>> Hi,
>> This series is v5 of the series to add suspend/resume support for Texas
>> Instruments AM335x SoC. It has gone through a rather major overhaul
>> since the last version and because of that has been split into multiple
>> different sets of patches, on which this series depends. Previous discussion
>> that influenced there changes can be found here [1]. This series depends on
>> generic sram exec mapping patch here [2], emif series here [3],
>> and wkup_m3_ipc series here [4]. I have pushed a branch containing the patches
>> from ALL required series here [5] for testing or a view of the high level
>> flow of the entire series.
>>
>> The largest change with this revision is the introduction of a
>> wkup_m3_ipc driver which handles all communication with the Cortex M3
>> present on am335x for handling low power tasks. Previously this was
>> handled in the wkup_m3_rproc driver (also sent in an earlier series)
>> but that driver is now only responsible for booting the wkup_m3. The
>> wkup_m3_ipc driver exposes an API with all required PM functionality
>> needed by the PM code introduced by this series, so the PM code has
>> shrunk considerably.
>>
>> Another major change is that the EMIF code previously present in the
>> sleep33xx asm code and pm33xx code for save and restore of EMIF context
>> and entry into low power mode has all been moved in to a separate EMIF
>> driver, further reducing the size of the PM code. Because of this, moving
>> the emif header defines into include/linux/ti_emif.h is no longer necessary.
>>
>> Other changes include clean up of the timer suspend/resume handlers, now
>> look up hwmod in init and use that handle along with renaming to
>> *_idle/*_unidle to avoid confusion with true suspend handlers. 
>>
>> Suspend support requires:
>> CONFIG_TI_EMIF_SRAM
>> CONFIG_WKUP_M3_RPROC
>> CONFIG_WKUP_M3_IPC
>>
>> And also requires AM335x USB support to be enabled to work for multiple
>> cycles. If you want to load firmware from rootfs in /lib/firmware you now
>> must also select CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
>>
>> This code works with version 0x189 of the CM3 firmware found here [6] on
>> the next branch, /bin/am335x-pm-firmware.elf.
> 
> Dave, does this series have dependencies to the other patches? Can some
> parts of this already be applied without breaking anything?
> 

The only patch with no dependencies is patch 1 (ARM: OMAP2+: timer: Add
suspend-resume callbacks for clkevent device). It's ready to be applied, I just
applied to v3.19-rc5 and built and booted on am335x-evm with no issue just to be
sure. It won't actually do anything until suspend is completely implemented.

Regards,
Dave

> Regards,
> 
> Tony
>  
>> [1] http://www.spinics.net/lists/linux-omap/msg109331.html
>> [2] http://www.spinics.net/linux/lists/kernel/msg1876629.html
>> [3] http://www.spinics.net/linux/lists/kernel/msg1876646.html
>> [4] http://www.spinics.net/linux/lists/kernel/msg1876642.html
>> [5] https://github.com/dgerlach/linux-pm/tree/rfc-pm-am335x-v3.18-rc6
>> [6] https://git.ti.com/ti-cm3-pm-firmware/amx3-cm3/commits/next
>>
>> Dave Gerlach (3):
>>   ARM: OMAP2+: AM33XX: Add assembly code for PM operations
>>   ARM: OMAP2+: AM33XX: Basic suspend resume support
>>   ARM: OMAP2+: AM33XX: Hookup AM33XX PM code into OMAP builds
>>
>> Vaibhav Bedia (1):
>>   ARM: OMAP2+: timer: Add suspend-resume callbacks for clkevent device

>>  arch/arm/boot/dts/am33xx.dtsi   |   2 +
>>  arch/arm/mach-omap2/Makefile    |   2 +
>>  arch/arm/mach-omap2/common.h    |   9 ++
>>  arch/arm/mach-omap2/io.c        |   1 +
>>  arch/arm/mach-omap2/pm.h        |   6 +
>>  arch/arm/mach-omap2/pm33xx.c    | 250 ++++++++++++++++++++++++++++++++++++++++
>>  arch/arm/mach-omap2/sleep33xx.S | 216 ++++++++++++++++++++++++++++++++++
>>  arch/arm/mach-omap2/timer.c     |  28 +++++
>>  8 files changed, 514 insertions(+)
>>  create mode 100644 arch/arm/mach-omap2/pm33xx.c
>>  create mode 100644 arch/arm/mach-omap2/sleep33xx.S
>>
>> -- 
>> 2.1.0
>>