[PATCH v3 3/9] mmc: sdhci: enable CMD23 for multi-block transfers

[Eric Chung]

Enable the host controller's support for the CMD23 (SET_BLOCK_COUNT)
command to manage multi-block read/write operations. This allows the
MMC core to use CMD23 in preference to the legacy CMD18/CMD25 plus
CMD12 sequence, reducing command overhead and improving I/O
performance on multi-block transfers.

Signed-off-by: Eric Chung <eric.chung at riscstar.com>

---
v3:
- Avoid to use quirk to enable CMD23. Use capability instead.
---
 drivers/mmc/mmc.c | 18 ++++++++++++++----
 include/mmc.h     |  6 +++++-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index f0e38efb262..bc8e9ee6d1c 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -461,6 +461,14 @@ static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
 	struct mmc_cmd cmd;
 	struct mmc_data data;
 
+	if (mmc->host_caps & MMC_CAP_CMD23) {
+		cmd.cmdidx = MMC_CMD_SET_BLOCK_COUNT;
+		cmd.cmdarg = blkcnt & 0x0000ffff;
+		cmd.resp_type = MMC_RSP_R1;
+		if (mmc_send_cmd(mmc, &cmd, NULL))
+			return 0;
+	}
+
 	if (blkcnt > 1)
 		cmd.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK;
 	else
@@ -481,7 +489,7 @@ static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
 	if (mmc_send_cmd(mmc, &cmd, &data))
 		return 0;
 
-	if (blkcnt > 1) {
+	if (blkcnt > 1 && !(mmc->host_caps & MMC_CAP_CMD23)) {
 		if (mmc_send_stop_transmission(mmc, false)) {
 #if !defined(CONFIG_XPL_BUILD) || defined(CONFIG_SPL_LIBCOMMON_SUPPORT)
 			log_err("mmc fail to send stop cmd\n");
@@ -1436,6 +1444,8 @@ static int sd_get_capabilities(struct mmc *mmc)
 
 	if (mmc->scr[0] & SD_DATA_4BIT)
 		mmc->card_caps |= MMC_MODE_4BIT;
+	if (!(mmc->scr[0] & SD_SCR_CMD23_SUPPORT))
+		mmc->host_caps &= ~MMC_CAP_CMD23;
 
 	/* Version 1.0 doesn't support switching */
 	if (mmc->version == SD_VERSION_1_0)
@@ -2963,9 +2973,9 @@ int mmc_get_op_cond(struct mmc *mmc, bool quiet)
 		return err;
 
 #ifdef CONFIG_MMC_QUIRKS
-	mmc->quirks = MMC_QUIRK_RETRY_SET_BLOCKLEN |
-		      MMC_QUIRK_RETRY_SEND_CID |
-		      MMC_QUIRK_RETRY_APP_CMD;
+	mmc->quirks |= MMC_QUIRK_RETRY_SET_BLOCKLEN |
+		       MMC_QUIRK_RETRY_SEND_CID |
+		       MMC_QUIRK_RETRY_APP_CMD;
 #endif
 
 	err = mmc_power_cycle(mmc);
diff --git a/include/mmc.h b/include/mmc.h
index 9509c9e9543..b663da71019 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -67,6 +67,7 @@ struct bd_info;
 #define MMC_CAP_NONREMOVABLE	BIT(14)
 #define MMC_CAP_NEEDS_POLL	BIT(15)
 #define MMC_CAP_CD_ACTIVE_HIGH  BIT(16)
+#define MMC_CAP_CMD23		BIT(17)
 
 #define MMC_MODE_8BIT		BIT(30)
 #define MMC_MODE_4BIT		BIT(29)
@@ -141,6 +142,8 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
 #define SD_HIGHSPEED_BUSY	0x00020000
 #define SD_HIGHSPEED_SUPPORTED	0x00020000
 
+#define SD_SCR_CMD23_SUPPORT	BIT(1)
+
 #define UHS_SDR12_BUS_SPEED	0
 #define HIGH_SPEED_BUS_SPEED	1
 #define UHS_SDR25_BUS_SPEED	1
@@ -343,7 +346,8 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
 
 #define MMC_QUIRK_RETRY_SEND_CID	BIT(0)
 #define MMC_QUIRK_RETRY_SET_BLOCKLEN	BIT(1)
-#define MMC_QUIRK_RETRY_APP_CMD	BIT(2)
+#define MMC_QUIRK_RETRY_APP_CMD		BIT(2)
+#define MMC_QUIRK_BLK_CMD23		BIT(3)
 
 enum mmc_voltage {
 	MMC_SIGNAL_VOLTAGE_000 = 0,

-- 
2.51.0