[PATCH v4 1/3] ARM: dts: aspeed: ast2600evb: Add sdhci node and gpio regulator for A2 evb.
joel at jms.id.au
Mon May 24 12:46:52 AEST 2021
On Mon, 24 May 2021 at 02:35, Steven Lee <steven_lee at aspeedtech.com> wrote:
> The 05/21/2021 09:25, Joel Stanley wrote:
> > Hi Steven,
> > On Thu, 20 May 2021 at 10:16, Steven Lee <steven_lee at aspeedtech.com> wrote:
> > >
> > > AST2600 A2(or newer) EVB has gpio regulators for toggling signal voltage
> > > between 3.3v and 1.8v, the patch adds sdhci node and gpio regulator in the
> > > new dts file and adds commment for describing the reference design.
> > spelling: comment
> Thanks, will correct the typo.
> > I need you to justify the separate dts for the A2 EVB.
> > What would happen if this device tree was loaded on to an A1 or A0?
> Since the clock default value(SCU210) of A1 and A0 are different to A2,
> the following error would happen if A2 device tree was loaded on A1/A0.
> [ 133.179825] mmc1: Reset 0x4 never completed.
> [ 133.184599] mmc1: sdhci: ============ SDHCI REGISTER DUMP ===========
> [ 133.191786] mmc1: sdhci: Sys addr: 0x00000000 | Version: 0x00000002
> [ 133.198972] mmc1: sdhci: Blk size: 0x00007008 | Blk cnt: 0x00000001
> [ 133.206158] mmc1: sdhci: Argument: 0x00000c00 | Trn mode: 0x00000013
> [ 133.213343] mmc1: sdhci: Present: 0x01f70001 | Host ctl: 0x00000011
> [ 133.220528] mmc1: sdhci: Power: 0x0000000f | Blk gap: 0x00000000
> [ 133.227713] mmc1: sdhci: Wake-up: 0x00000000 | Clock: 0x00008007
> [ 133.234898] mmc1: sdhci: Timeout: 0x0000000b | Int stat: 0x00000000
> [ 133.242083] mmc1: sdhci: Int enab: 0x00ff0083 | Sig enab: 0x00ff0083
> [ 133.249268] mmc1: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00000000
> [ 133.256453] mmc1: sdhci: Caps: 0x07f80080 | Caps_1: 0x00000007
> [ 133.263638] mmc1: sdhci: Cmd: 0x0000341a | Max curr: 0x001f0f08
> [ 133.270824] mmc1: sdhci: Resp: 0x00000000 | Resp: 0x01dd7f7f
> [ 133.278009] mmc1: sdhci: Resp: 0x325b5900 | Resp: 0x00400e00
> [ 133.285193] mmc1: sdhci: Host ctl2: 0x00000000
> [ 133.290148] mmc1: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0xbe041200
> [ 133.297332] mmc1: sdhci: ============================================
> Besides, A1/A0 EVBs don't have regulator, vmmc and vqmmc should be
> removed from sdhci node of A1/A0 dts.
> > Would this device tree be used for the A3 (and any future revision?)
> Yes, A3 can use the A2 dts.
> > An alternative proposal: we modify the ast2600-evb.dts to support the
> > A2 (which I assume would also support the A3).
> > If we need a separate board file for the A0 and A1 EVB, we add a new
> > one that supports these earlier revisions. Or we decide to only
> > support the latest revision in mainline.
> In this patch, I add a new dts to support A2 sdhci, and include the
> original dts since the other settings can be loaded on A2.
> Do you mean creating a new file(e.g. aspeed-ast2600-evb-a1.dts) for A1,
> and modifying the original aspeed-ast2600-evb.dts for supporting A2?
Yes, that would be my suggestion. The aspeed-ast2600-evb-a1.dts could
include the aspeed-ast2600-evb.dts.
> If we decide to only support the latest version in mainline, users
> should mark vmmc and vqmmc as comment and modify clk-phase manually
> for supporting A1.
If you believe there will be users of the A1 for some time, then I
think it makes sense to support both A1 and future boards in mainline.
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