[PATCH] mmc: zynq_sdhci: Reset the host controller

[PATCH] mmc: zynq_sdhci: Reset the host controller

[Venkatesh Yadav Abbarapu]

Reset the host controller at the early stage of probe so that the
configuration will be done properly for reboot cases.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
---
 drivers/mmc/zynq_sdhci.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
index 0e2bdab4e7e..5d797dfd0c4 100644
--- a/drivers/mmc/zynq_sdhci.c
+++ b/drivers/mmc/zynq_sdhci.c
@@ -1127,6 +1127,27 @@ static int arasan_sdhci_probe(struct udevice *dev)
 	if (arasan_sdhci_is_compatible(dev, SDHCI_COMPATIBLE_VERSAL_NET_EMMC))
 		priv->internal_phy_reg = true;
 
+	ret = reset_get_bulk(dev, &priv->resets);
+	if (ret == -ENOTSUPP || ret == -ENOENT) {
+		dev_warn(dev, "Reset not found\n");
+		return 0;
+	} else if (ret) {
+		dev_err(dev, "Reset failed\n");
+		return ret;
+	}
+
+	ret = reset_assert_bulk(&priv->resets);
+	if (ret) {
+		dev_err(dev, "Reset assert failed\n");
+		return ret;
+	}
+
+	ret = reset_deassert_bulk(&priv->resets);
+	if (ret) {
+		dev_err(dev, "Reset release failed\n");
+		return ret;
+	}
+
 	ret = clk_get_by_index(dev, 0, &clk);
 	if (ret < 0) {
 		dev_err(dev, "failed to get clock\n");
-- 
2.34.1

Re: [PATCH] mmc: zynq_sdhci: Reset the host controller

[Michal Simek]

On 6/25/25 07:26, Venkatesh Yadav Abbarapu wrote:
> Reset the host controller at the early stage of probe so that the
> configuration will be done properly for reboot cases.
> 
> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
> ---
>   drivers/mmc/zynq_sdhci.c | 21 +++++++++++++++++++++
>   1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
> index 0e2bdab4e7e..5d797dfd0c4 100644
> --- a/drivers/mmc/zynq_sdhci.c
> +++ b/drivers/mmc/zynq_sdhci.c
> @@ -1127,6 +1127,27 @@ static int arasan_sdhci_probe(struct udevice *dev)
>   	if (arasan_sdhci_is_compatible(dev, SDHCI_COMPATIBLE_VERSAL_NET_EMMC))
>   		priv->internal_phy_reg = true;
>   
> +	ret = reset_get_bulk(dev, &priv->resets);
> +	if (ret == -ENOTSUPP || ret == -ENOENT) {
> +		dev_warn(dev, "Reset not found\n");
> +		return 0;
> +	} else if (ret) {
> +		dev_err(dev, "Reset failed\n");
> +		return ret;
> +	}
> +
> +	ret = reset_assert_bulk(&priv->resets);
> +	if (ret) {
> +		dev_err(dev, "Reset assert failed\n");
> +		return ret;
> +	}
> +
> +	ret = reset_deassert_bulk(&priv->resets);
> +	if (ret) {
> +		dev_err(dev, "Reset release failed\n");
> +		return ret;
> +	}

reset can still be optional right?

It means if reset is found you should call assert/deassert.
Not sure if there is any need to keep reset for some time.

If reset is not preset it should pass.
If reset is present but error out because whatever reason you should return error.

M


> +
>   	ret = clk_get_by_index(dev, 0, &clk);
>   	if (ret < 0) {
>   		dev_err(dev, "failed to get clock\n");