[U-Boot] [RFC 1/3][v4] mmc: checking status after commands with R1b response

[Raffaele Recalcati]

From: Raffaele Recalcati <raffaele.recalcati at bticino.it>

It is recommended to check card status after these kind of commands.
This is done using CMD13 (SEND_STATUS) JEDEC command until
the card is ready.
In case of error the card status field is displayed.

Signed-off-by: Raffaele Recalcati <raffaele.recalcati at bticino.it>
---
 drivers/mmc/mmc.c |   60 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 include/mmc.h     |    4 +++
 2 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 6805b33..fc1792a 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -48,6 +48,40 @@ int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
 	return mmc->send_cmd(mmc, cmd, data);
 }
 
+int mmc_send_status(struct mmc *mmc, int timeout)
+{
+	struct mmc_cmd cmd;
+	int err;
+	int status;
+
+	cmd.cmdidx = MMC_CMD_SEND_STATUS;
+	cmd.resp_type = MMC_RSP_R1;
+	cmd.cmdarg = 0;
+	cmd.flags = 0;
+
+	do {
+		err = mmc_send_cmd(mmc, &cmd, NULL);
+		if (err)
+			return err;
+		else if (cmd.response[0] & MMC_STATUS_RDY_FOR_DATA)
+			break;
+
+		udelay(1000);
+
+		if (cmd.response[0] & MMC_STATUS_MASK) {
+			printf("Status Error: 0x%08X\n", cmd.response[0]);
+			return COMM_ERR;
+		}
+	} while (timeout--);
+
+	if (!timeout) {
+		printf("Timeout waiting card ready\n");
+		return TIMEOUT;
+	}
+
+	return 0;
+}
+
 int mmc_set_blocklen(struct mmc *mmc, int len)
 {
 	struct mmc_cmd cmd;
@@ -82,6 +116,7 @@ mmc_write_blocks(struct mmc *mmc, ulong start, lbaint_t blkcnt, const void*src)
 {
 	struct mmc_cmd cmd;
 	struct mmc_data data;
+	int timeout = 1000;
 
 	if ((start + blkcnt) > mmc->block_dev.lba) {
 		printf("MMC: block number 0x%lx exceeds max(0x%lx)\n",
@@ -121,6 +156,9 @@ mmc_write_blocks(struct mmc *mmc, ulong start, lbaint_t blkcnt, const void*src)
 			printf("mmc fail to send stop cmd\n");
 			return 0;
 		}
+
+		/* Waiting for the ready status */
+		mmc_send_status(mmc, 1000);
 	}
 
 	return blkcnt;
@@ -158,6 +196,7 @@ int mmc_read_blocks(struct mmc *mmc, void *dst, ulong start, lbaint_t blkcnt)
 {
 	struct mmc_cmd cmd;
 	struct mmc_data data;
+	int timeout = 1000;
 
 	if (blkcnt > 1)
 		cmd.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK;
@@ -189,6 +228,9 @@ int mmc_read_blocks(struct mmc *mmc, void *dst, ulong start, lbaint_t blkcnt)
 			printf("mmc fail to send stop cmd\n");
 			return 0;
 		}
+
+		/* Waiting for the ready status */
+		mmc_send_status(mmc, 1000);
 	}
 
 	return blkcnt;
@@ -369,15 +411,23 @@ int mmc_send_ext_csd(struct mmc *mmc, char *ext_csd)
 int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value)
 {
 	struct mmc_cmd cmd;
+	int timeout = 1000;
+	int ret;
 
 	cmd.cmdidx = MMC_CMD_SWITCH;
 	cmd.resp_type = MMC_RSP_R1b;
 	cmd.cmdarg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
-		(index << 16) |
-		(value << 8);
+				 (index << 16) |
+				 (value << 8);
 	cmd.flags = 0;
 
-	return mmc_send_cmd(mmc, &cmd, NULL);
+	ret = mmc_send_cmd(mmc, &cmd, NULL);
+
+	/* Waiting for the ready status */
+	mmc_send_status(mmc, 1000);
+
+	return ret;
+
 }
 
 int mmc_change_freq(struct mmc *mmc)
@@ -610,6 +660,7 @@ int mmc_startup(struct mmc *mmc)
 	u64 cmult, csize;
 	struct mmc_cmd cmd;
 	char ext_csd[512];
+	int timeout = 1000;
 
 	/* Put the Card in Identify Mode */
 	cmd.cmdidx = MMC_CMD_ALL_SEND_CID;
@@ -722,6 +773,9 @@ int mmc_startup(struct mmc *mmc)
 	cmd.flags = 0;
 	err = mmc_send_cmd(mmc, &cmd, NULL);
 
+	/* Waiting for the ready status */
+	mmc_send_status(mmc, 1000);
+
 	if (err)
 		return err;
 
diff --git a/include/mmc.h b/include/mmc.h
index fcd0fd1..4ee8e1c 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -94,6 +94,10 @@
 #define OCR_BUSY	0x80000000
 #define OCR_HCS		0x40000000
 
+#define MMC_STATUS_MASK		(~0x0206BF7F)
+#define MMC_STATUS_RDY_FOR_DATA (1<<8)
+#define MMC_STATUS_CURR_STATE	(0xf<<9)
+
 #define MMC_VDD_165_195		0x00000080	/* VDD voltage 1.65 - 1.95 */
 #define MMC_VDD_20_21		0x00000100	/* VDD voltage 2.0 ~ 2.1 */
 #define MMC_VDD_21_22		0x00000200	/* VDD voltage 2.1 ~ 2.2 */
-- 
1.7.0.4