[U-Boot] [PATCH 6/6] arm: mx5: Add support for DENX M53EVK

[Marek Vasut <marex@denx.de>]

Dear Beno?t Th?baudeau,

[...]

> > +static void setup_iomux_nand(void)
> > +{
> > +	mxc_request_iomux(MX53_PIN_NANDF_WE_B, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_RE_B, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_CLE, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_ALE, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_WP_B, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_RB0, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_NANDF_CS0, IOMUX_CONFIG_ALT0);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA0, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA1, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA2, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA3, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA4, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA5, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA6, IOMUX_CONFIG_ALT3);
> > +	mxc_request_iomux(MX53_PIN_ATA_DATA7, IOMUX_CONFIG_ALT3);
> > +
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_WE_B, PAD_CTL_DRV_HIGH);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_RE_B, PAD_CTL_DRV_HIGH);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_CLE, PAD_CTL_DRV_HIGH);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_ALE, PAD_CTL_DRV_HIGH);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_WP_B, PAD_CTL_PUE_PULL |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_RB0, PAD_CTL_PUE_PULL |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_NANDF_CS0, PAD_CTL_DRV_HIGH);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA0, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA1, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA2, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA3, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA4, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA5, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA6, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +	mxc_iomux_set_pad(MX53_PIN_ATA_DATA7, PAD_CTL_DRV_HIGH |
> > +			PAD_CTL_100K_PU | PAD_CTL_PKE_ENABLE);
> > +}
> 
> Like for 5/6, why is this function needed? When booting from NAND

Where did you get the information the board can only boot from NAND? Did I 
mistakenly present it somewhere like that please?

Anyway, no, it can also boot from SD and USB at least.

> the boot
> ROM sets the NAND pads appropriately itself (see 7.5.2.4), so unless it
> reverts those changes to the IOMUX reset values afterwards, there is no
> need to set the NAND IOMUX again. It's not as if the board were using NAND
> after having been booted from another source (like mx53ard does).

I want to use NAND when booted from other sources, yes.

> Or perhaps you are planning to add more boot sources later, in which case
> there are configs missing for M4IF and WEIM (see mx53ard's
> setup_iomux_nand()).

Yes, but even without this configuration, the NAND works perfectly well when 
booted from SD. Am I missing something here?

[...]