mmc: sdhci-uhs2: Add quirk for devices with broken UHS-2

The GL9755 in Apple silicon Macboo Pros and Mac Studios has
non-functioning UHS-2 under linux.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/mmc/host/sdhci-uhs2.c

@@ -1162,7 +1162,8 @@ static void __sdhci_uhs2_add_host_v4(struct sdhci_host *host, u32 caps1)
 	mmc = host->mmc;
 
 	/* Support UHS2 */
-	if (caps1 & SDHCI_SUPPORT_UHS2)
+	if ((caps1 & SDHCI_SUPPORT_UHS2) &&
+		!(host->quirks2 & SDHCI_QUIRK2_BROKEN_UHS2))
 		mmc->caps2 |= MMC_CAP2_SD_UHS2;
 
 	max_current_caps2 = sdhci_readl(host, SDHCI_MAX_CURRENT_1);

drivers/mmc/host/sdhci.h

@@ -537,6 +537,8 @@ struct sdhci_host {
 /* Issue CMD and DATA reset together */
 #define SDHCI_QUIRK2_ISSUE_CMD_DAT_RESET_TOGETHER	(1<<19)
 
+#define SDHCI_QUIRK2_BROKEN_UHS2			(1<<27)
+
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
 	phys_addr_t mapbase;	/* physical address base */