Merge tag 'nfc-next-4.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo...

[firefly-linux-kernel-4.4.55.git] / drivers / of / device.c

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 46d6c75c14040903edf9b14f2ec2030c179b2c1e..20c1332a00182cb43bb707e2a7468dce73cdf991 100644 (file)
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -2,6 +2,9 @@
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_iommu.h>
+#include <linux/dma-mapping.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
@@ -66,6 +69,87 @@ int of_device_add(struct platform_device *ofdev)
        return device_add(&ofdev->dev);
 }
 
+/**
+ * of_dma_configure - Setup DMA configuration
+ * @dev:       Device to apply DMA configuration
+ * @np:                Pointer to OF node having DMA configuration
+ *
+ * Try to get devices's DMA configuration from DT and update it
+ * accordingly.
+ *
+ * If platform code needs to use its own special DMA configuration, it
+ * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
+ * to fix up DMA configuration.
+ */
+void of_dma_configure(struct device *dev, struct device_node *np)
+{
+       u64 dma_addr, paddr, size;
+       int ret;
+       bool coherent;
+       unsigned long offset;
+       struct iommu_ops *iommu;
+
+       /*
+        * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
+        * setup the correct supported mask.
+        */
+       if (!dev->coherent_dma_mask)
+               dev->coherent_dma_mask = DMA_BIT_MASK(32);
+
+       /*
+        * Set it to coherent_dma_mask by default if the architecture
+        * code has not set it.
+        */
+       if (!dev->dma_mask)
+               dev->dma_mask = &dev->coherent_dma_mask;
+
+       ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
+       if (ret < 0) {
+               dma_addr = offset = 0;
+               size = dev->coherent_dma_mask + 1;
+       } else {
+               offset = PFN_DOWN(paddr - dma_addr);
+
+               /*
+                * Add a work around to treat the size as mask + 1 in case
+                * it is defined in DT as a mask.
+                */
+               if (size & 1) {
+                       dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
+                                size);
+                       size = size + 1;
+               }
+
+               if (!size) {
+                       dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
+                       return;
+               }
+               dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
+       }
+
+       dev->dma_pfn_offset = offset;
+
+       /*
+        * Limit coherent and dma mask based on size and default mask
+        * set by the driver.
+        */
+       dev->coherent_dma_mask = min(dev->coherent_dma_mask,
+                                    DMA_BIT_MASK(ilog2(dma_addr + size)));
+       *dev->dma_mask = min((*dev->dma_mask),
+                            DMA_BIT_MASK(ilog2(dma_addr + size)));
+
+       coherent = of_dma_is_coherent(np);
+       dev_dbg(dev, "device is%sdma coherent\n",
+               coherent ? " " : " not ");
+
+       iommu = of_iommu_configure(dev, np);
+       dev_dbg(dev, "device is%sbehind an iommu\n",
+               iommu ? " " : " not ");
+
+       arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
+}
+EXPORT_SYMBOL_GPL(of_dma_configure);
+
 int of_device_register(struct platform_device *pdev)
 {
        device_initialize(&pdev->dev);