ti-sdk-beagleboard-06.00.00 Power button

Hi Dibin,

There are various methods to add a gpio button management in the kernal. One of the ways is to use the things which are already done. I suggest you to search for the gpio_buttons structure in the board file and how it is used.

Also look at the ../kernel/drivers/input/keyboard/gpio_keys.c and gpio_keys_polled.c  files.

About suspend/resume the drivers implement the suspend() function defined in the LDM. When the suspend for the system is asserted, the suspend() function is called for all drivers. The drivers release the clocks to reach the desired low power state. The actual transition to suspend is implemented in the function omap3_pm_suspend().

BR

Tsvetolin Shulev

Hi Shulev,

Thankyou for your quick response.

Suspend path seems to be more complex.

But I am still having issues with suspend , As i mentioned above

The terminal command 

echo mem > /sys/power/state

The Terminal shows

PM: Syncing filesystems ... done.

Then I had to fire  Ctrl C  from the terminal to complete suspend.

The same thing is happening when I call pm_suspend(PM_SUSPEND_MEM) from my driver.

The suspend sequence stucks at PM: Syncing filesystems ... done.

Regards,

Dibin

Hi Shulev , 

The same issue was reported before , I didnt found a solution for this issue.

http://e2e.ti.com/support/dsp/omap_applications_processors/f/447/t/154148.aspx

Regards,

Dibin

Hi Shulev,

Can you give me any input for suspend/resume support.

I want to do the suspend from my custom battery driver.

Regards,

Dibin

Hi Dibin,

I suggest you two articles which could be useful for understanding and testing suspend / resume operations with omap3530. The second article is not exactly related to omap3530 but gives general information which could be adopted for omap3:

http://processors.wiki.ti.com/index.php/UserGuidePowerMgmt_PSP_04.02.00.07

http://processors.wiki.ti.com/index.php/DM814x_AM387x_PM_Suspend_resume_overview

BR

Tsvetolin Shulev

Hi Shulev.

   For entering into sleep mode by   echo mem  > /sys/power/state 

   I need to remove the btwilink and st_drv  drivers by rmmod command.

  I am planning to do button driver.

  Can you point me how to do this driver removal from a button driver file.

Regards,

Dibin

Hi Dibin,

You could write your own button driver which should be very similar to writing a gpio driver because the button is connected to a gpio. There are many examples for writing gpio drivers in the net. Look at some of then at the link below:

https://www.kernel.org/doc/Documentation/input/input-programming.txt

http://blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:gpio-keys

http://stackoverflow.com/questions/21263281/my-first-linux-driver-its-for-a-gpio-button-a-little-confused-on-interrupts

BR

Tsvetolin Shulev

Hi Shulev,

Thankyou very much for your reply.

I have successfully tested the sleep from my driver.

But Its Not working with btwilink  st_drv LKM.

These drivers are preventing system to enter in sleep state.

When I do rmmod btwilink and rmmod st_drv all works fine.

Is there any way to remove these drivers  from my driver and load it back when  waking up from sleep?

Or Is there any patch available for btwilink and st_drv Modules to support sleep.

Waiting for your reply .

Dibin