Questions on iomux for imx6dq on CD/WP signals

[christophe]

Hi,

I work with iomux IMX6DQ (v3.4.0.3) and a Sabre MCIMX6Q-SDQ board.

1- In usdhc3 block, there's no signals CD and WP. This block can be though used to drive a classic sd card, as done in Sabre board. So, CD and WP signals are expected in the usdhc3 block, no ?

2- Another trouble now: with usdhc2 block.

In usdhc2 block with IOmux, RD and WP signals are like that, when gpio solution is choosen:

     usdhc2     :     SD2_CD_B               GPIO04 (ALT 6)

                              SD2_WP                    GPIO02 (ALT 6)

Now, in the Sabre board schematics, these signals use pads:

     SD2_CD_B     :     NANDF_D2 (F16)

     SD2_WP          :     NANDF_D3 (D17)

And in config file board-mx6q_sabred.h, we find the following config:

     MX6Q_PAS_NANDF_D2__GPIO_2_2               /* SD2_CD */

     MX6Q_PAS_NANDF_D3__GPIO_2_3               /* SD2_WP */

This config is consistent with schematics, no doubt about that.

My trouble is that used gpio pads in the Sabre board are not those given in IOmux. As the Sabre is correctly working,  it seems there's a problem in IOmux. No ?

If i go wrong, please let me know.

Rgds,

Christophe.

[fabio_estevam · Accepted solution]

1. SD4 signals on sabresd board are connected into a eMMC that is soldered into the board, so no need to handle card detect / write protect on this port.

[christophe]

Yes, i agree with you, no need for SD4 which is a eMMC. But the trouble is on the others ...

[christophe]

An other to formulate is:

1- How Sabre board can process card detect/protect functions with uSDHC3 whereas this function is theorically not present ?

2- How NANDF_D2/D3 signals can be used  to process card detect/protect functions with uSDHC2, whereas these signals can't be selected in iomux tool ?