mmc: sdhci-acpi: Add 64-bit DMA support

Set the DMA mask during the first call to ->enable_dma() to
make use of the SDHCI_USE_64_BIT_DMA flag.

This patch is dependent on
commit 8a2f38ddfeb526c30b3ec209468172a30a38d996 ("ACPI / platform: provide default DMA mask")
which provides the dev->dma_mask pointer without
which dma_set_mask_and_coherent() will always fail.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 9cccc0e89b0435928ca375d8b1640c5008cc6551..310976307954063ada1cda8651be07ff3b033987 100644 (file)
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -76,6 +76,7 @@ struct sdhci_acpi_host {
        const struct sdhci_acpi_slot    *slot;
        struct platform_device          *pdev;
        bool                            use_runtime_pm;
+       bool                            dma_setup;
 };
 
 static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
@@ -85,7 +86,29 @@ static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
 
 static int sdhci_acpi_enable_dma(struct sdhci_host *host)
 {
-       return 0;
+       struct sdhci_acpi_host *c = sdhci_priv(host);
+       struct device *dev = &c->pdev->dev;
+       int err = -1;
+
+       if (c->dma_setup)
+               return 0;
+
+       if (host->flags & SDHCI_USE_64_BIT_DMA) {
+               if (host->quirks2 & SDHCI_QUIRK2_BROKEN_64_BIT_DMA) {
+                       host->flags &= ~SDHCI_USE_64_BIT_DMA;
+               } else {
+                       err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+                       if (err)
+                               dev_warn(dev, "Failed to set 64-bit DMA mask\n");
+               }
+       }
+
+       if (err)
+               err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+
+       c->dma_setup = !err;
+
+       return err;
 }
 
 static void sdhci_acpi_int_hw_reset(struct sdhci_host *host)
@@ -305,21 +328,6 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
                goto err_free;
        }
 
-       if (!dev->dma_mask) {
-               u64 dma_mask;
-
-               if (sdhci_readl(host, SDHCI_CAPABILITIES) & SDHCI_CAN_64BIT) {
-                       /* 64-bit DMA is not supported at present */
-                       dma_mask = DMA_BIT_MASK(32);
-               } else {
-                       dma_mask = DMA_BIT_MASK(32);
-               }
-
-               err = dma_coerce_mask_and_coherent(dev, dma_mask);
-               if (err)
-                       goto err_free;
-       }
-
        if (c->slot) {
                if (c->slot->probe_slot) {
                        err = c->slot->probe_slot(pdev, hid, uid);