mmc: Add concept of an 'embedded' SDIO device.

This is required to support chips which use SDIO for signaling/
communication but do not implement the various card enumeration registers
as required for full SD / SDIO cards.

mmc: sdio: Fix bug where we're freeing the CIS tables we never allocated when using EMBEDDED_SDIO
mmc: Add max_blksize to embedded SDIO data

Signed-off-by: San Mehat <san@google.com>

4 files changed, 95 insertions, 17 deletions

diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index 1972b00f801..85c2e1acd15 100644
--- a/drivers/mmc/core/Kconfig
+++ b/drivers/mmc/core/Kconfig
@@ -28,8 +28,17 @@ config MMC_CLKGATE
 
 	  If unsure, say N.
 
+config MMC_EMBEDDED_SDIO
+	boolean "MMC embedded SDIO device support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	help
+	  If you say Y here, support will be added for embedded SDIO
+	  devices which do not contain the necessary enumeration
+	  support in hardware to be properly detected.
+
 config MMC_PARANOID_SD_INIT
 	bool "Enable paranoid SD card initialization (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
 	help
 	  If you say Y here, the MMC layer will be extra paranoid
 	  about re-trying SD init requests. This can be a useful
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index f545a3e6eb8..bcee017827e 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2521,6 +2521,22 @@ int mmc_pm_notify(struct notifier_block *notify_block,
 }
 #endif
 
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+void mmc_set_embedded_sdio_data(struct mmc_host *host,
+				struct sdio_cis *cis,
+				struct sdio_cccr *cccr,
+				struct sdio_embedded_func *funcs,
+				int num_funcs)
+{
+	host->embedded_sdio_data.cis = cis;
+	host->embedded_sdio_data.cccr = cccr;
+	host->embedded_sdio_data.funcs = funcs;
+	host->embedded_sdio_data.num_funcs = num_funcs;
+}
+
+EXPORT_SYMBOL(mmc_set_embedded_sdio_data);
+#endif
+
 static int __init mmc_init(void)
 {
 	int ret;
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index bd7bacc950d..3a60f59ad4e 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -28,6 +28,10 @@
 #include "sdio_ops.h"
 #include "sdio_cis.h"
 
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+#include <linux/mmc/sdio_ids.h>
+#endif
+
 static int sdio_read_fbr(struct sdio_func *func)
 {
 	int ret;
@@ -709,19 +713,35 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 		goto finish;
 	}
 
-	/*
-	 * Read the common registers.
-	 */
-	err = sdio_read_cccr(card);
-	if (err)
-		goto remove;
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	if (host->embedded_sdio_data.cccr)
+		memcpy(&card->cccr, host->embedded_sdio_data.cccr, sizeof(struct sdio_cccr));
+	else {
+#endif
+		/*
+		 * Read the common registers.
+		 */
+		err = sdio_read_cccr(card);
+		if (err)
+			goto remove;
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	}
+#endif
 
-	/*
-	 * Read the common CIS tuples.
-	 */
-	err = sdio_read_common_cis(card);
-	if (err)
-		goto remove;
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	if (host->embedded_sdio_data.cis)
+		memcpy(&card->cis, host->embedded_sdio_data.cis, sizeof(struct sdio_cis));
+	else {
+#endif
+		/*
+		 * Read the common CIS tuples.
+		 */
+		err = sdio_read_common_cis(card);
+		if (err)
+			goto remove;
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	}
+#endif
 
 	if (oldcard) {
 		int same = (card->cis.vendor == oldcard->cis.vendor &&
@@ -1115,14 +1135,36 @@ int mmc_attach_sdio(struct mmc_host *host)
 	funcs = (ocr & 0x70000000) >> 28;
 	card->sdio_funcs = 0;
 
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	if (host->embedded_sdio_data.funcs)
+		card->sdio_funcs = funcs = host->embedded_sdio_data.num_funcs;
+#endif
+
 	/*
 	 * Initialize (but don't add) all present functions.
 	 */
 	for (i = 0; i < funcs; i++, card->sdio_funcs++) {
-		err = sdio_init_func(host->card, i + 1);
-		if (err)
-			goto remove;
-
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+		if (host->embedded_sdio_data.funcs) {
+			struct sdio_func *tmp;
+
+			tmp = sdio_alloc_func(host->card);
+			if (IS_ERR(tmp))
+				goto remove;
+			tmp->num = (i + 1);
+			card->sdio_func[i] = tmp;
+			tmp->class = host->embedded_sdio_data.funcs[i].f_class;
+			tmp->max_blksize = host->embedded_sdio_data.funcs[i].f_maxblksize;
+			tmp->vendor = card->cis.vendor;
+			tmp->device = card->cis.device;
+		} else {
+#endif
+			err = sdio_init_func(host->card, i + 1);
+			if (err)
+				goto remove;
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+		}
+#endif
 		/*
 		 * Enable Runtime PM for this func (if supported)
 		 */
diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 40989e6bb53..7a0b801714b 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -24,6 +24,10 @@
 #include "sdio_cis.h"
 #include "sdio_bus.h"
 
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+#include <linux/mmc/host.h>
+#endif
+
 /* show configuration fields */
 #define sdio_config_attr(field, format_string)				\
 static ssize_t								\
@@ -257,7 +261,14 @@ static void sdio_release_func(struct device *dev)
 {
 	struct sdio_func *func = dev_to_sdio_func(dev);
 
-	sdio_free_func_cis(func);
+#ifdef CONFIG_MMC_EMBEDDED_SDIO
+	/*
+	 * If this device is embedded then we never allocated
+	 * cis tables for this func
+	 */
+	if (!func->card->host->embedded_sdio_data.funcs)
+#endif
+		sdio_free_func_cis(func);
 
 	if (func->info)
 		kfree(func->info);