[PATCH v2 0/2] PM / devfreq: Add support frequency support

[Chanwoo Choi <cw00.choi@samsung.com>]

The devfreq has two case to enter the suspend mode for devfreq dev as following:
case 1: Some devfreq device call the 'devfreq_suspend/resume_device()'
        directly on the fly regardless of 'echo mem > /sys/power/state'.
case 2: The system enter the suspend mode by using 'echo mem > sys/power/state'.

These patches support the suspend frequency on devfreq subsystem for case 1.
Lin Huang posted the patch[1] to support the case1. So, I rework Lin Huang's
patch[1] to consider the passive devfreq device using passive governor.

And Tobias would support the following two features on third patches.
He already posted the patches[2] to support the case 2.
- Add new devfreq_{suspend|resume} function for all registered devfreq devices
- Support the reference count to prevent the duplicate call of
  devfreq_{suspend|resume}_device. Tobias and me already discussed it on
  patch[3].

[1] https://patchwork.kernel.org/patch/9445007/
- "[v7] PM/devfreq: add suspend frequency support"
[2] https://www.spinics.net/lists/linux-samsung-soc/msg56602.html
- [RFC v2 0/7] PM / devfreq: draft for OPP suspend impl (even draftier)
[3] https://www.spinics.net/lists/linux-samsung-soc/msg56632.html

Also, I tested these patches on Exynos3250-Rinato board and made the
patch[4][5]. But, the patches[4][5] would be posted after posting the third
patches by Tobias Jakobi.
[4] https://git.kernel.org/cgit/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-test&id=cf2893454b126380e5513261ec8e3aa94d898e51
[5] https://git.kernel.org/cgit/linux/kernel/git/chanwoo/linux.git/commit/?h=devfreq-test&id=fb75ab14e7fbd5b72784dea2c45f7cb171490b6e


Depends on:
- These patches depend on v4.1-rc1 and patches[6][7]

[6] https://lkml.org/lkml/2016/12/28/91
- [PATCH v2 0/3] PM / devfreq: Fix the bug and add reviewer for devfreq support
[7] https://lkml.org/lkml/2016/12/28/102
- [PATCH v2 0/8] PM / devfreq: Update the devfreq and devfreq-event device

Chanwoo Choi (1):
  PM / devfreq: Add separate target function

Lin Huang (1):
  PM / devfreq: Add suspend frequency support

 drivers/devfreq/devfreq.c | 96 +++++++++++++++++++++++++++++++++++------------
 include/linux/devfreq.h   |  2 +
 2 files changed, 73 insertions(+), 25 deletions(-)

-- 
1.9.1