Hi Arnd,

On Thu, Apr 7, 2022 at 1:38 PM Arnd Bergmann [off-list ref] wrote:

On Thu, Apr 7, 2022 at 7:06 PM Brad Larson [off-list ref] wrote:

quoted

On Thu, Apr 7, 2022 at 12:13 AM Adrian Hunter [off-list ref] wrote:

quoted

What is the relationship between cadence and pensando elba?

Pensando licensed the cadence controller, its 100% cadence IP.  The
integration issue we ran into was with the accessors where we have the
workaround.  The initial patch added a separate Elba driver file but
the feedback was the Elba support didn't justify doing that and to add
to sdhci-cacence.c.

I looked back at the earlier reviews now, I think the main problem with
versions 1 and 2 was that it had the abstraction the wrong way around,
so you added the complexity of having multiple files, without the benefits.

I still think that the cleanest approach would be to have it the way I
suggested in my reply to v1, with an elba specific platform driver
that calls into the generic cadence code, but the generic code knowing
nothing about the front-end.

Then again, it sounds like there was already an agreement about
the approach you took here, so let's stay with that and hope we don't
get any other chips with the same IP block in the future.

Thanks for looking this over.  I won't change for now in the patch
update in process.  This will likely get another look as I've added a
node to the device tree to enable an added reset driver which can
hardware reset the emmc.  The current cadence sdhci driver does not
include this and I've currently added filling out
mmc_host_ops.card_hw_reset like below, yet one more thing different
for our platforms not in the common driver.

@@ -404,6 +550,17 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        if (ret)
                goto free;

+       if (host->mmc->caps & MMC_CAP_HW_RESET) {
+               priv->rst_hw =

devm_reset_control_get_optional_exclusive(dev, "hw");
+               if (IS_ERR(priv->rst_hw)) {
+                       ret = PTR_ERR(priv->rst_hw);
+                       if (ret == -ENOENT)
+                               priv->rst_hw = NULL;
+               } else {
+                       host->mmc_host_ops.card_hw_reset = sdhci_mmc_hw_reset;
+               }
+       }
+
        ret = sdhci_add_host(host);

Regards,
Brad

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