Optimizing Power of sd card problem

[[email protected]]

Hi,

  In my project, I use SPIM4 to access sd card . It is worked well.    Then ,I optimizing power of sd card. The power of my sd card is controlled by LDO.The LDO is enabled by P0.12.

 When P0.12  output high level, LDO is enable.So SD card get the 3.3V power. After this step, I mount the SD card successfull. 

 Until now , there is no problem. But when  I set P0.12 to low level after unmount sd card, the sd card power pin still have 2.7 voltage.After debugging ,I found the reason is that sd card fetch the power source mosi and cs pin.But no matter how i set the GPIO register of MOSI and CS,  it  still can't solve. Then I tried to disable the SPIM4, the problem is solved.

So, I need to disable SDMMC driver when I goto sleep,enable SDMMC driver when i need use it. Therefore, my question ： How to turn off the SPIM4 after unmount the sd card in zephyr? I use the nrf connect sdk.

[Einarh]

Hello

Are you using the Zephyr SPI driver or the nrfx SPIM driver?

With the nrfx driver I believe you could use nrfx_spim_uninit()?

You say you disabled SPIM4 and the problem was solved, what method did you use to disable SPIM4 in this case?

Best regards,

Einar

[[email protected]]

Yes, I am using nrfx SPIM driver. And you will see two figures below. 

I have used subsystem moudule "disk", the zephyr dirver "disk" and the spi driver "spi_nrfx_spim".

I disable the spim4 by to configure the spim4 register using vscode debug console.As shown below.

If I use directly spi dirver.I suppose that the sdmmc will not mount successfull again,beause the sdmmc finnally use spim4 dirver.

[Einarh]

[email protected] said:

If I use directly spi dirver.I suppose that the sdmmc will not mount successfull again,beause the sdmmc finnally use spim4 dirver.

I'm not sure what you mean by this, could you please explain?

[[email protected]]

After I call fs_unmount(&mnt_pt), if I call spi4_unint directly, I can close spim4.

But when I call fs_unmount(&mnt_pt) again, an error should be reported. Because the initial configuration of spim is performed at system startup.

[Einarh]

It is still not clear to me exactly what your issue is.

After you unmount and uninit spim4 you are unable to init it again?

What is not working like you expect it to?

[[email protected]]

What I mean is, because of I am using the fs module of zephyr, and the fs module calls the disk_access module of zephyr, and disk_access calls the nrfx_spi driver, if I use the nrfx_spi underlying driver directly, will it affect the program logic of disk_access? I think it is dangerous to directly call the spi underlying driver.

[Einarh]

I don't think this will be a problem as long as you make sure spi is initialized when you init fs again