[PATCH master] mci: bcm2835: reset host controller on barebox shutdown

[Ahmad Fatoum]

We don't usually disable MMC controllers on barebox shutdown, because
they don't DMA on their own, unlike e.g. network controllers.

Booting Linux v5.17.0 on a Raspberry Pi 4 in 32-bit mode still has the
MMC host controller driver complain:

  [   22.464887] mmc1: Got data interrupt 0x00000002 even though no
  			data operation was in progress.

Fix this by resetting the SDHCI once barebox is done with it.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/mci/mci-bcm2835.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/mci/mci-bcm2835.c b/drivers/mci/mci-bcm2835.c
index f092156f9a83..c5b226ba033c 100644
--- a/drivers/mci/mci-bcm2835.c
+++ b/drivers/mci/mci-bcm2835.c
@@ -385,6 +385,8 @@ static int bcm2835_mci_probe(struct device_d *hw_dev)
 	host->sdhci.read32 = bcm2835_sdhci_read32;
 	host->sdhci.write32 = bcm2835_sdhci_write32;
 
+	hw_dev->priv = host;
+
 	mci_of_parse(&host->mci);
 
 	iores = dev_request_mem_resource(hw_dev, 0);
@@ -420,6 +422,15 @@ static int bcm2835_mci_probe(struct device_d *hw_dev)
 	return mci_register(&host->mci);
 }
 
+static void bcm2835_mci_remove(struct device_d *dev)
+{
+	struct bcm2835_mci_host *host = dev->priv;
+
+	sdhci_write32(&host->sdhci,
+		      SDHCI_CLOCK_CONTROL__TIMEOUT_CONTROL__SOFTWARE_RESET,
+		      0x00);
+}
+
 static __maybe_unused struct of_device_id bcm2835_mci_compatible[] = {
 	{
 		.compatible = "brcm,bcm2835-sdhci",
@@ -433,6 +444,7 @@ static __maybe_unused struct of_device_id bcm2835_mci_compatible[] = {
 static struct driver_d bcm2835_mci_driver = {
 	.name = "bcm2835_mci",
 	.probe = bcm2835_mci_probe,
+	.remove = bcm2835_mci_remove,
 	.of_compatible = DRV_OF_COMPAT(bcm2835_mci_compatible),
 };
 
-- 
2.30.2