[U-Boot] i.MX6 PAD_CTL_SPEED_LOW possibly wrong

[Jonas Mark (BT-FIR/ENG1)]

Hello,

In arch/arm/include/asm/mach-imx/iomux-v3.h you find defines of
PAD_CTL_SPEED_*. For the i.MX 6 SX, i.MX 6 UL, and the i.MX 6 ULL the
PAD_CTL_SPEED_LOW field is set to 0. For all other i.MX6 processors it
will be 1. I compared that to the definition found in the
i.MX 6Solo/6DualLite Application Processor Reference Manual, Rev. 3,
Page 2646 [1] for the IOMUXC_SW_PAD_CTL_PAD_SD2_CLK register. I found
that the i.MX 6 S and i.MX 6 DL the PAD_CTL_SPEED_LOW field shall be 0,
too.

I then checked more Reference Manuals (RM) looking at the
IOMUXC_SW_PAD_CTL_PAD_SD2_CLK or IOMUXC_SW_PAD_CTL_PAD_GPIO1_IO00
register and found the following.

i.MX 6 Solo RM [1]:     00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 DualLite RM [1]: 00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 Dual RM [2]:     00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 Quad RM [2]:     00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 SoloLite RM [3]: 00 RESERVED, 01 Low, 10 Medium, 11 Maximum
i.MX 6 SoloX RM [4]:    00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 DualPlus RM [5]: 00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 QuadPlus RM [5]: 00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 ULL RM [6]:      00 Low, 01 Medium, 10 Medium, 11 Maximum
i.MX 6 UltraLite RM:    only available under a licensing agreement

Combining the knowledge from the RMs above and the existing code, it
seems that only the SoloLite is different. Thus, I propose the
attached patch.

Greetings,
Mark

[1] https://www.nxp.com/docs/en/reference-manual/IMX6SDLRM.pdf
[2] https://www.nxp.com/docs/en/reference-manual/IMX6DQRM.pdf
[3] https://www.nxp.com/docs/en/reference-manual/IMX6SLRM.pdf
[4] https://www.nxp.com/docs/en/reference-manual/IMX6SXRM.pdf
[5] https://www.nxp.com/docs/en/reference-manual/iMX6DQPRM.pdf
[6] https://www.nxp.com/docs/en/reference-manual/IMX6ULLRM.pdf
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-arm-imx6-fix-PAD_CTL_SPEED_LOW-constant.patch
Type: application/octet-stream
Size: 1862 bytes
Desc: 0001-arm-imx6-fix-PAD_CTL_SPEED_LOW-constant.patch
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20180413/e8ea592a/attachment.obj>