mmc: sdhci: add a quirk for single block transactions

This patch defines a quirk to disable the block count
for single block transactions.
It is a preparation and will be used by Fujitsu
SDHCI controller f_sdh30 driver.
Signed-off-by: Vincent Yang <Vincent.Yang@tw.fujitsu.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -904,7 +904,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
 static void sdhci_set_transfer_mode(struct sdhci_host *host,
 	struct mmc_command *cmd)
 {
-	u16 mode;
+	u16 mode = 0;
 	struct mmc_data *data = cmd->data;
 
 	if (data == NULL) {
@@ -922,9 +922,11 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 
 	WARN_ON(!host->data);
 
+	if (!(host->quirks2 & SDHCI_QUIRK2_SUPPORT_SINGLE))
 		mode = SDHCI_TRNS_BLK_CNT_EN;
+
 	if (mmc_op_multi(cmd->opcode) || data->blocks > 1) {
-		mode |= SDHCI_TRNS_MULTI;
+		mode = SDHCI_TRNS_BLK_CNT_EN | SDHCI_TRNS_MULTI;
 		/*
 		 * If we are sending CMD23, CMD12 never gets sent
 		 * on successful completion (so no Auto-CMD12).

include/linux/mmc/sdhci.h

@@ -113,6 +113,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400		(1<<11)
 /* forced tuned clock */
 #define SDHCI_QUIRK2_TUNING_WORK_AROUND			(1<<12)
+/* disable the block count for single block transactions */
+#define SDHCI_QUIRK2_SUPPORT_SINGLE			(1<<13)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */