mmc: s3c6410: add new quirk in sdhci driver and update ADMA descriptor build

The s3c6410 sdhci controller does not support the 'End' attribute and NOP
attribute in the same 8-Byte ADMA descriptor.  This patch adds a new quirk
to identify sdhci host contollers with such behaviour.  In addition to
this, for controllers using the new quirk, the last entry in the ADMA
descritor table is marked with the 'End' attribute (instead of using a NOP
descriptor with 'End' attribute).

Signed-off-by: Maurus Cuelenaere <mcuelenaere@gmail.com>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Acked-by: Ben Dooks <ben-linux@fluff.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>

2 files changed, 17 insertions, 5 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 02b365f5a4be..d27cc9178041 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -496,12 +496,22 @@ static int sdhci_adma_table_pre(struct sdhci_host *host,
                 WARN_ON((desc - host->adma_desc) > (128 * 2 + 1) * 4);
         }
 
-        /*
-         * Add a terminating entry.
-         */
+        if (host->quirks & SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC) {
+                /*
+                * Mark the last descriptor as the terminating descriptor
+                */
+                if (desc != host->adma_desc) {
+                        desc -= 8;
+                        desc[0] |= 0x2; /* end */
+                }
+        } else {
+                /*
+                * Add a terminating entry.
+                */
 
-        /* nop, end, valid */
-        sdhci_set_adma_desc(desc, 0, 0, 0x3);
+                /* nop, end, valid */
+                sdhci_set_adma_desc(desc, 0, 0, 0x3);
+        }
 
         /*
          * Resync align buffer as we might have changed it.
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index af08a1935b06..c8468134adc9 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -238,6 +238,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK             (1<<24)
 /* Controller reports wrong base clock capability */
 #define SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN               (1<<25)
+/* Controller cannot support End Attribute in NOP ADMA descriptor */
+#define SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC               (1<<26)
 
         int                     irq;            /* Device IRQ */
         void __iomem *          ioaddr;         /* Mapped address */