sdhci: scatter-gather (ADMA) support

Add support for the scatter-gather DMA mode present on newer controllers.
As the mode requires 32-bit alignment, non-aligned chunks are handled by
using a bounce buffer.

Also add some new quirks to handle controllers that have bugs in the
ADMA engine.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 0716dcffd511..deb607c52c0d 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -142,6 +142,7 @@ static int jmicron_probe(struct sdhci_pci_chip *chip)
         if (chip->pdev->revision == 0) {
                 chip->quirks |= SDHCI_QUIRK_32BIT_DMA_ADDR |
                           SDHCI_QUIRK_32BIT_DMA_SIZE |
+                          SDHCI_QUIRK_32BIT_ADMA_SIZE |
                           SDHCI_QUIRK_RESET_AFTER_REQUEST;
         }
 
@@ -206,6 +207,22 @@ static void jmicron_enable_mmc(struct sdhci_host *host, int on)
 
 static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
 {
+        if (slot->chip->pdev->revision == 0) {
+                u16 version;
+
+                version = readl(slot->host->ioaddr + SDHCI_HOST_VERSION);
+                version = (version & SDHCI_VENDOR_VER_MASK) >>
+                        SDHCI_VENDOR_VER_SHIFT;
+
+                /*
+                 * Older versions of the chip have lots of nasty glitches
+                 * in the ADMA engine. It's best just to avoid it
+                 * completely.
+                 */
+                if (version < 0xAC)
+                        slot->host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
+        }
+
         /*
          * The secondary interface requires a bit set to get the
          * interrupts.