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authorSantosh Shilimkar <santosh.shilimkar@ti.com>2014-04-24 11:30:04 -0400
committerSantosh Shilimkar <santosh.shilimkar@ti.com>2014-05-07 09:21:21 -0400
commit591c1ee465ce5372385dbc41e7d3e36cbb477bd8 (patch)
tree9a1a70d862e00f8431956479eb15899565f0f6bd /drivers/of
parent92ea637edea36e58236e3124f199161da6f5c5de (diff)
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of: configure the platform device dma parameters
Retrieve DMA configuration from DT and setup platform device's DMA parameters. The DMA configuration in DT has to be specified using "dma-ranges" and "dma-coherent" properties if supported. We setup dma_pfn_offset using "dma-ranges" and dma_coherent_ops using "dma-coherent" device tree properties. The set_arch_dma_coherent_ops macro has to be defined by arch if it supports coherent dma_ops. Otherwise, set_arch_dma_coherent_ops() is declared as nop. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Olof Johansson <olof@lixom.net> Cc: Grant Likely <grant.likely@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/platform.c65
1 files changed, 59 insertions, 6 deletions
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1daebefa..91fa9838b56f 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -187,6 +187,64 @@ struct platform_device *of_device_alloc(struct device_node *np,
EXPORT_SYMBOL(of_device_alloc);
/**
+ * of_dma_configure - Setup DMA configuration
+ * @dev: Device to apply DMA configuration
+ *
+ * Try to get devices's DMA configuration from DT and update it
+ * accordingly.
+ *
+ * In case if platform code need to use own special DMA configuration,it
+ * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event
+ * to fix up DMA configuration.
+ */
+static void of_dma_configure(struct platform_device *pdev)
+{
+ u64 dma_addr, paddr, size;
+ int ret;
+ struct device *dev = &pdev->dev;
+
+#if defined(CONFIG_MICROBLAZE)
+ pdev->archdata.dma_mask = 0xffffffffUL;
+#endif
+
+ /*
+ * Set default dma-mask to 32 bit. Drivers are expected to setup
+ * the correct supported 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;
+
+ /*
+ * if dma-coherent property exist, call arch hook to setup
+ * dma coherent operations.
+ */
+ if (of_dma_is_coherent(dev->of_node)) {
+ set_arch_dma_coherent_ops(dev);
+ dev_dbg(dev, "device is dma coherent\n");
+ }
+
+ /*
+ * if dma-ranges property doesn't exist - just return else
+ * setup the dma offset
+ */
+ ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
+ if (ret < 0) {
+ dev_dbg(dev, "no dma range information to setup\n");
+ return;
+ }
+
+ /* DMA ranges found. Calculate and set dma_pfn_offset */
+ dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr);
+ dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);
+}
+
+/**
* of_platform_device_create_pdata - Alloc, initialize and register an of_device
* @np: pointer to node to create device for
* @bus_id: name to assign device
@@ -211,12 +269,7 @@ static struct platform_device *of_platform_device_create_pdata(
if (!dev)
return NULL;
-#if defined(CONFIG_MICROBLAZE)
- dev->archdata.dma_mask = 0xffffffffUL;
-#endif
- dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
- if (!dev->dev.dma_mask)
- dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+ of_dma_configure(dev);
dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;