[PATCH 2/3] mci: handle SDIO cards gracefully

[Sascha Hauer <s.hauer@pengutronix.de>]

Detect SDIO cards properly to be able to return from card detection
without errors. So far a SDIO card reports several errors during
detection:

ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Error while executing command 8
ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Status: 0x1FF0001, Interrupt: 0x18000
ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Error while executing command 55
ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Status: 0x1FF0001, Interrupt: 0x18000
ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Error while executing command 1
ERROR: bcm2835_mci 3f300000.mmc@7e300000.of: Status: 0x1FF0001, Interrupt: 0x18000

With this we can now detect SDIO cards without reporting errors, or
to put it differently: barebox now has SDIO support ;)

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/mci/mci-core.c | 24 +++++++++++++++++++++++-
 include/mci.h          |  4 ++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 8cda07e711..44a577e8c3 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -232,6 +232,15 @@ static int mci_go_idle(struct mci *mci)
 	return 0;
 }
 
+static int sdio_send_op_cond(struct mci *mci)
+{
+	struct mci_cmd cmd;
+
+	mci_setup_cmd(&cmd, SD_IO_SEND_OP_COND, 0, MMC_RSP_SPI_R4 | MMC_RSP_R4 | MMC_CMD_BCR);
+
+	return mci_send_cmd(mci, &cmd, NULL);
+}
+
 /**
  * FIXME
  * @param mci MCI instance
@@ -1596,7 +1605,9 @@ static void mci_info(struct device_d *dev)
 	mci_print_caps(host->host_caps);
 
 	printf("Card information:\n");
-	printf("  Attached is a %s card\n", IS_SD(mci) ? "SD" : "MMC");
+	printf("  Card type: %s\n", mci->sdio ? "SDIO" : IS_SD(mci) ? "SD" : "MMC");
+	if (mci->sdio)
+		return;
 	printf("  Version: %s\n", mci_version_string(mci));
 	printf("  Capacity: %u MiB\n", (unsigned)(mci->capacity >> 20));
 
@@ -1809,6 +1820,16 @@ static int mci_card_probe(struct mci *mci)
 		goto on_error;
 	}
 
+	if (!host->no_sdio) {
+		rc = sdio_send_op_cond(mci);
+		if (!rc) {
+			mci->ready_for_use = true;
+			mci->sdio = true;
+			dev_info(&mci->dev, "SDIO card detected, ignoring\n");
+			return 0;
+		}
+	}
+
 	/* Check if this card can handle the "SD Card Physical Layer Specification 2.0" */
 	if (!host->no_sd) {
 		rc = sd_send_if_cond(mci);
@@ -2086,6 +2107,7 @@ void mci_of_parse_node(struct mci_host *host,
 	host->broken_cd = of_property_read_bool(np, "broken-cd");
 	host->non_removable = of_property_read_bool(np, "non-removable");
 	host->no_sd = of_property_read_bool(np, "no-sd");
+	host->no_sdio = of_property_read_bool(np, "no-sdio");
 	host->disable_wp = of_property_read_bool(np, "disable-wp");
 }
 
diff --git a/include/mci.h b/include/mci.h
index d3201e17e6..56a5659e50 100644
--- a/include/mci.h
+++ b/include/mci.h
@@ -91,6 +91,8 @@
 #define SD_CMD_APP_SEND_OP_COND		41
 #define SD_CMD_APP_SEND_SCR		51
 
+#define SD_IO_SEND_OP_COND		5 /* bcr  [23:0] OCR         R4  */
+
 /* SCR definitions in different words */
 #define SD_HIGHSPEED_BUSY	0x00020000
 #define SD_HIGHSPEED_SUPPORTED	0x00020000
@@ -431,6 +433,7 @@ struct mci_host {
 	int broken_cd;		/**< card detect is broken */
 	bool non_removable;	/**< device is non removable */
 	bool no_sd;		/**< do not send SD commands during initialization */
+	bool no_sdio;		/**< do not send SDIO commands during initialization */
 	bool disable_wp;	/**< ignore write-protect detection logic */
 	struct regulator *supply;
 
@@ -469,6 +472,7 @@ struct mci {
 	struct mci_host *host;		/**< the host for this card */
 	struct device_d dev;		/**< the device for our disk (mcix) */
 	unsigned version;
+	bool sdio;		/**< card is a SDIO card */
 	/** != 0 when a high capacity card is connected (OCR -> OCR_HCS) */
 	int high_capacity;
 	unsigned card_caps;	/**< Card's capabilities */
-- 
2.30.2