A3720 - Disable slot when eMMC is not present

[Pali Rohár]

Hello! I looked at what is initialized and enabled for sd/emmc slots and
I found out that comphy mmc needs to be enabled if at least one slot is
used (e.g. SD card) and then remaining part is slot initialization in
xenon driver.

I wrote quick patch to disable slot when unregistering mmc device from
U-Boot and also unregister emmc on A3720 from U-Boot when it is not
present. But I have not tested it yet.

What do you think about it?

diff --git a/board/Marvell/mvebu_armada-37xx/board.c b/board/Marvell/mvebu_armada-37xx/board.c
index f67b04b78c..1b9e7520cc 100644
--- a/board/Marvell/mvebu_armada-37xx/board.c
+++ b/board/Marvell/mvebu_armada-37xx/board.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <dm/device-internal.h>
 #include <env.h>
 #include <i2c.h>
 #include <init.h>
@@ -84,12 +85,10 @@ int board_init(void)
 #ifdef CONFIG_BOARD_LATE_INIT
 int board_late_init(void)
 {
+	struct udevice *dev;
 	struct mmc *mmc_dev;
 	bool ddr4, emmc;
 
-	if (env_get("fdtfile"))
-		return 0;
-
 	if (!of_machine_is_compatible("globalscale,espressobin"))
 		return 0;
 
@@ -101,6 +100,16 @@ int board_late_init(void)
 	mmc_dev = find_mmc_device(1);
 	emmc = (mmc_dev && mmc_init(mmc_dev) == 0);
 
+	/* if eMMC is not present then remove it from DM */
+	if (!emmc && mmc_dev) {
+		dev = mmc_dev->dev;
+		device_remove(dev, DM_REMOVE_NORMAL);
+		device_unbind(dev);
+	}
+
+	if (env_get("fdtfile"))
+		return 0;
+
 	if (ddr4 && emmc)
 		env_set("fdtfile", "marvell/armada-3720-espressobin-v7-emmc.dtb");
 	else if (ddr4)
diff --git a/drivers/mmc/xenon_sdhci.c b/drivers/mmc/xenon_sdhci.c
index 6ce9d00d0a..da9882cbf6 100644
--- a/drivers/mmc/xenon_sdhci.c
+++ b/drivers/mmc/xenon_sdhci.c
@@ -350,6 +350,16 @@ static void xenon_mmc_enable_slot(struct sdhci_host *host, u8 slot)
 	sdhci_writel(host, var, SDHC_SYS_OP_CTRL);
 }
 
+/* Disable specific slot */
+static void xenon_mmc_disable_slot(struct sdhci_host *host, u8 slot)
+{
+	u32 var;
+
+	var = sdhci_readl(host, SDHC_SYS_OP_CTRL);
+	var &= ~(SLOT_MASK(slot) << SLOT_ENABLE_SHIFT);
+	sdhci_writel(host, var, SDHC_SYS_OP_CTRL);
+}
+
 /* Enable Parallel Transfer Mode */
 static void xenon_mmc_enable_parallel_tran(struct sdhci_host *host, u8 slot)
 {
@@ -515,6 +525,14 @@ static int xenon_sdhci_probe(struct udevice *dev)
 	return ret;
 }
 
+static int xenon_sdhci_remove(struct udevice *dev)
+{
+	struct sdhci_host *host = dev_get_priv(dev);
+
+	xenon_mmc_disable_slot(host, XENON_MMC_SLOT_ID_HYPERION);
+	return 0;
+}
+
 static int xenon_sdhci_ofdata_to_platdata(struct udevice *dev)
 {
 	struct sdhci_host *host = dev_get_priv(dev);
@@ -564,6 +582,7 @@ U_BOOT_DRIVER(xenon_sdhci_drv) = {
 	.ops		= &sdhci_ops,
 	.bind		= xenon_sdhci_bind,
 	.probe		= xenon_sdhci_probe,
+	.remove		= xenon_sdhci_remove,
 	.priv_auto_alloc_size = sizeof(struct xenon_sdhci_priv),
 	.platdata_auto_alloc_size = sizeof(struct xenon_sdhci_plat),
 };