mmc: split mmc_sd_init_card()

This series adds support for SD combo cards to MMC/SD driver stack.

SD combo consists of SD memory and SDIO parts in one package.  Since the
parts have a separate SD command sets, after initialization, they can be
treated as independent cards on one bus.

Changes are divided into two patches.  First is just moving initialization
code around so that SD memory part init can be called from SDIO init.
Second patch is a proper change enabling SD memory along SDIO.  I tried to
move as much no-op changes to the first patch so that it's easier to
follow the required changes to initialization flow for SDIO cards.

This is based on Simplified SDIO spec v.2.00.  The init sequence is
slightly modified to follow current SD memory init implementation.
Command sequences, assuming SD memory and SDIO indeed ignore unknown
commands, are the same as before for both parts.

This patch:

Prepare for SD-combo (IO+mem) support by splitting SD memory
card init and related functions.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/core/sd.c

@@ -59,7 +59,7 @@ static const unsigned int tacc_mant[] = {
 /*
  * Given the decoded CSD structure, decode the raw CID to our CID structure.
  */
-static void mmc_decode_cid(struct mmc_card *card)
+void mmc_decode_cid(struct mmc_card *card)
 {
 	u32 *resp = card->raw_cid;
 
@@ -238,7 +238,7 @@ out:
 /*
  * Test if the card supports high-speed mode and, if so, switch to it.
  */
-static int mmc_switch_hs(struct mmc_card *card)
+int mmc_sd_switch_hs(struct mmc_card *card)
 {
 	int err;
 	u8 *status;
@@ -272,9 +272,9 @@ static int mmc_switch_hs(struct mmc_card *card)
 		printk(KERN_WARNING "%s: Problem switching card "
 			"into high-speed mode!\n",
 			mmc_hostname(card->host));
+		err = 0;
 	} else {
-		mmc_card_set_highspeed(card);
-		mmc_set_timing(card->host, MMC_TIMING_SD_HS);
+		err = 1;
 	}
 
 out:
@@ -320,26 +320,16 @@ static const struct attribute_group *sd_attr_groups[] = {
 	NULL,
 };
 
-static struct device_type sd_type = {
+struct device_type sd_type = {
 	.groups = sd_attr_groups,
 };
 
 /*
- * Handle the detection and initialisation of a card.
- *
- * In the case of a resume, "oldcard" will contain the card
- * we're trying to reinitialise.
+ * Fetch CID from card.
  */
-static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
-	struct mmc_card *oldcard)
+int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid)
 {
-	struct mmc_card *card;
 	int err;
-	u32 cid[4];
-	unsigned int max_dtr;
-
-	BUG_ON(!host);
-	WARN_ON(!host->claimed);
 
 	/*
 	 * Since we're changing the OCR value, we seem to
@@ -361,23 +351,136 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 
 	err = mmc_send_app_op_cond(host, ocr, NULL);
 	if (err)
-		goto err;
+		return err;
 
-	/*
-	 * Fetch CID from card.
-	 */
 	if (mmc_host_is_spi(host))
 		err = mmc_send_cid(host, cid);
 	else
 		err = mmc_all_send_cid(host, cid);
+
+	return err;
+}
+
+int mmc_sd_get_csd(struct mmc_host *host, struct mmc_card *card)
+{
+	int err;
+
+	/*
+	 * Fetch CSD from card.
+	 */
+	err = mmc_send_csd(card, card->raw_csd);
 	if (err)
-		goto err;
+		return err;
 
-	if (oldcard) {
-		if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0) {
-			err = -ENOENT;
-			goto err;
+	err = mmc_decode_csd(card);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
+	bool reinit)
+{
+	int err;
+
+	if (!reinit) {
+		/*
+		 * Fetch SCR from card.
+		 */
+		err = mmc_app_send_scr(card, card->raw_scr);
+		if (err)
+			return err;
+
+		err = mmc_decode_scr(card);
+		if (err)
+			return err;
+
+		/*
+		 * Fetch switch information from card.
+		 */
+		err = mmc_read_switch(card);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * For SPI, enable CRC as appropriate.
+	 * This CRC enable is located AFTER the reading of the
+	 * card registers because some SDHC cards are not able
+	 * to provide valid CRCs for non-512-byte blocks.
+	 */
+	if (mmc_host_is_spi(host)) {
+		err = mmc_spi_set_crc(host, use_spi_crc);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Check if read-only switch is active.
+	 */
+	if (!reinit) {
+		int ro = -1;
+
+		if (host->ops->get_ro)
+			ro = host->ops->get_ro(host);
+
+		if (ro < 0) {
+			printk(KERN_WARNING "%s: host does not "
+				"support reading read-only "
+				"switch. assuming write-enable.\n",
+				mmc_hostname(host));
+		} else if (ro > 0) {
+			mmc_card_set_readonly(card);
 		}
+	}
+
+	return 0;
+}
+
+unsigned mmc_sd_get_max_clock(struct mmc_card *card)
+{
+	unsigned max_dtr = (unsigned int)-1;
+
+	if (mmc_card_highspeed(card)) {
+		if (max_dtr > card->sw_caps.hs_max_dtr)
+			max_dtr = card->sw_caps.hs_max_dtr;
+	} else if (max_dtr > card->csd.max_dtr) {
+		max_dtr = card->csd.max_dtr;
+	}
+
+	return max_dtr;
+}
+
+void mmc_sd_go_highspeed(struct mmc_card *card)
+{
+	mmc_card_set_highspeed(card);
+	mmc_set_timing(card->host, MMC_TIMING_SD_HS);
+}
+
+/*
+ * Handle the detection and initialisation of a card.
+ *
+ * In the case of a resume, "oldcard" will contain the card
+ * we're trying to reinitialise.
+ */
+static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
+	struct mmc_card *oldcard)
+{
+	struct mmc_card *card;
+	int err;
+	u32 cid[4];
+
+	BUG_ON(!host);
+	WARN_ON(!host->claimed);
+
+	err = mmc_sd_get_cid(host, ocr, cid);
+	if (err)
+		return err;
+
+	if (oldcard) {
+		if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0)
+			return -ENOENT;
 
 		card = oldcard;
 	} else {
@@ -385,10 +488,8 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 		 * Allocate card structure.
 		 */
 		card = mmc_alloc_card(host, &sd_type);
-		if (IS_ERR(card)) {
-			err = PTR_ERR(card);
-			goto err;
-		}
+		if (IS_ERR(card))
+			return PTR_ERR(card);
 
 		card->type = MMC_TYPE_SD;
 		memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
@@ -400,22 +501,15 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	if (!mmc_host_is_spi(host)) {
 		err = mmc_send_relative_addr(host, &card->rca);
 		if (err)
-			goto free_card;
+			return err;
 
 		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
 	}
 
 	if (!oldcard) {
-		/*
-		 * Fetch CSD from card.
-		 */
-		err = mmc_send_csd(card, card->raw_csd);
+		err = mmc_sd_get_csd(host, card);
 		if (err)
-			goto free_card;
-
-		err = mmc_decode_csd(card);
-		if (err)
-			goto free_card;
+			return err;
 
 		mmc_decode_cid(card);
 	}
@@ -426,61 +520,26 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 	if (!mmc_host_is_spi(host)) {
 		err = mmc_select_card(card);
 		if (err)
-			goto free_card;
+			return err;
 	}
 
-	if (!oldcard) {
-		/*
-		 * Fetch SCR from card.
-		 */
-		err = mmc_app_send_scr(card, card->raw_scr);
-		if (err)
-			goto free_card;
-
-		err = mmc_decode_scr(card);
-		if (err < 0)
-			goto free_card;
-
-		/*
-		 * Fetch switch information from card.
-		 */
-		err = mmc_read_switch(card);
-		if (err)
-			goto free_card;
-	}
-
-	/*
-	 * For SPI, enable CRC as appropriate.
-	 * This CRC enable is located AFTER the reading of the
-	 * card registers because some SDHC cards are not able
-	 * to provide valid CRCs for non-512-byte blocks.
-	 */
-	if (mmc_host_is_spi(host)) {
-		err = mmc_spi_set_crc(host, use_spi_crc);
-		if (err)
-			goto free_card;
-	}
+	err = mmc_sd_setup_card(host, card, oldcard != NULL);
+	if (err)
+		goto free_card;
 
 	/*
 	 * Attempt to change to high-speed (if supported)
 	 */
-	err = mmc_switch_hs(card);
-	if (err)
+	err = mmc_sd_switch_hs(card);
+	if (err > 0)
+		mmc_sd_go_highspeed(card);
+	else if (err)
 		goto free_card;
 
 	/*
-	 * Compute bus speed.
+	 * Set bus speed.
 	 */
-	max_dtr = (unsigned int)-1;
-
-	if (mmc_card_highspeed(card)) {
-		if (max_dtr > card->sw_caps.hs_max_dtr)
-			max_dtr = card->sw_caps.hs_max_dtr;
-	} else if (max_dtr > card->csd.max_dtr) {
-		max_dtr = card->csd.max_dtr;
-	}
-
-	mmc_set_clock(host, max_dtr);
+	mmc_set_clock(host, mmc_sd_get_max_clock(card));
 
 	/*
 	 * Switch to wider bus (if supported).
@@ -494,30 +553,12 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
 		mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
 	}
 
-	/*
-	 * Check if read-only switch is active.
-	 */
-	if (!oldcard) {
-		if (!host->ops->get_ro || host->ops->get_ro(host) < 0) {
-			printk(KERN_WARNING "%s: host does not "
-				"support reading read-only "
-				"switch. assuming write-enable.\n",
-				mmc_hostname(host));
-		} else {
-			if (host->ops->get_ro(host) > 0)
-				mmc_card_set_readonly(card);
-		}
-	}
-
-	if (!oldcard)
-		host->card = card;
-
+	host->card = card;
 	return 0;
 
 free_card:
 	if (!oldcard)
 		mmc_remove_card(card);
-err:
 
 	return err;
 }

drivers/mmc/core/sd.h

@@ -0,0 +1,17 @@
+#ifndef _MMC_CORE_SD_H
+#define _MMC_CORE_SD_H
+
+#include <linux/mmc/card.h>
+
+extern struct device_type sd_type;
+
+int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid);
+int mmc_sd_get_csd(struct mmc_host *host, struct mmc_card *card);
+void mmc_decode_cid(struct mmc_card *card);
+int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
+	bool reinit);
+unsigned mmc_sd_get_max_clock(struct mmc_card *card);
+int mmc_sd_switch_hs(struct mmc_card *card);
+void mmc_sd_go_highspeed(struct mmc_card *card);
+
+#endif

drivers/mmc/core/sdio.c

@@ -18,6 +18,7 @@
 
 #include "core.h"
 #include "bus.h"
+#include "sd.h"
 #include "sdio_bus.h"
 #include "mmc_ops.h"
 #include "sd_ops.h"
@@ -245,10 +246,26 @@ static int sdio_enable_hs(struct mmc_card *card)
 	if (ret)
 		return ret;
 
-	mmc_card_set_highspeed(card);
-	mmc_set_timing(card->host, MMC_TIMING_SD_HS);
+	return 1;
+}
 
-	return 0;
+static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
+{
+	unsigned max_dtr;
+
+	if (mmc_card_highspeed(card)) {
+		/*
+		 * The SDIO specification doesn't mention how
+		 * the CIS transfer speed register relates to
+		 * high-speed, but it seems that 50 MHz is
+		 * mandatory.
+		 */
+		max_dtr = 50000000;
+	} else {
+		max_dtr = card->cis.max_dtr;
+	}
+
+	return max_dtr;
 }
 
 /*
@@ -351,23 +368,15 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	 * Switch to high-speed (if supported).
 	 */
 	err = sdio_enable_hs(card);
-	if (err)
+	if (err > 0)
+		mmc_sd_go_highspeed(card);
+	else if (err)
 		goto remove;
 
 	/*
 	 * Change to the card's maximum speed.
 	 */
-	if (mmc_card_highspeed(card)) {
-		/*
-		 * The SDIO specification doesn't mention how
-		 * the CIS transfer speed register relates to
-		 * high-speed, but it seems that 50 MHz is
-		 * mandatory.
-		 */
-		mmc_set_clock(host, 50000000);
-	} else {
-		mmc_set_clock(host, card->cis.max_dtr);
-	}
+	mmc_set_clock(host, mmc_sdio_get_max_clock(card));
 
 	/*
 	 * Switch to wider bus (if supported).