[PATCH 1/1] dt: Add general DMA window parser

[Hiroshi Doyu]

Hi,

Try again with fixing Thierry's commnets, Thanks.

>From 9a632c24949e46df197a216ca95f684edd1db693 Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <hdoyu at nvidia.com>
Date: Wed, 18 Apr 2012 12:09:03 +0300
Subject: [PATCH 1/1] dt: Add general DMA window parser

This code was stolen from:
	"arch/microblaze/kernel/prom_parse.c"
	"arch/powerpc/kernel/prom_parse.c"

Once "ibm," prefix is removed from dts file. This generic one could
replace the originals.

Signed-off-by: Hiroshi DOYU <hdoyu at nvidia.com>
---
 drivers/of/Kconfig         |    4 ++++
 drivers/of/Makefile        |    1 +
 drivers/of/of_dma.c        |   35 +++++++++++++++++++++++++++++++++++
 include/linux/of_address.h |   10 ++++++++++
 4 files changed, 50 insertions(+), 0 deletions(-)

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index dfba3e6..3b0298b 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -83,4 +83,8 @@ config OF_MTD
 	depends on MTD
 	def_bool y
 
+config OF_DMA
+	depends on HAS_DMA
+	def_bool y
+
 endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index e027f44..711ff5b 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_OF_MDIO)	+= of_mdio.o
 obj-$(CONFIG_OF_PCI)	+= of_pci.o
 obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
 obj-$(CONFIG_OF_MTD)	+= of_mtd.o
+obj-$(CONFIG_OF_DMA)	+= of_dma.o
diff --git a/drivers/of/of_dma.c b/drivers/of/of_dma.c
new file mode 100644
index 0000000..a34db5a
--- /dev/null
+++ b/drivers/of/of_dma.c
@@ -0,0 +1,35 @@
+/*
+ * Stolen from:
+ *	"arch/microblaze/kernel/prom_parse.c"
+ *	"arch/powerpc/kernel/prom_parse.c"
+ */
+
+#include <linux/of_address.h>
+
+void of_parse_dma_window(struct device_node *dn, const void *dma_window_prop,
+		unsigned long *busno, unsigned long *phys, unsigned long *size)
+{
+	const __be32 *dma_window;
+	u32 cells;
+	const unsigned char *prop;
+
+	dma_window = dma_window_prop;
+
+	/* busno is always one cell */
+	if (busno)
+		*busno = be32_to_cpup(dma_window++);
+
+	prop = of_get_property(dn, "#dma-address-cells", NULL);
+	if (!prop)
+		prop = of_get_property(dn, "#address-cells", NULL);
+
+	cells = prop ? *(__be32 *)prop : of_n_addr_cells(dn);
+	*phys = of_read_number(dma_window, cells);
+
+	dma_window += cells;
+
+	prop = of_get_property(dn, "#dma-size-cells", NULL);
+	cells = prop ? *(__be32 *)prop : of_n_size_cells(dn);
+	*size = of_read_number(dma_window, cells);
+}
+
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 01b925a..2a0f7c6 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -21,6 +21,10 @@ extern void __iomem *of_iomap(struct device_node *device, int index);
 extern const u32 *of_get_address(struct device_node *dev, int index,
 			   u64 *size, unsigned int *flags);
 
+extern void of_parse_dma_window(struct device_node *dn,
+		       const void *dma_window_prop, unsigned long *busno,
+			       unsigned long *phys, unsigned long *size);
+
 #ifndef pci_address_to_pio
 static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
 #define pci_address_to_pio pci_address_to_pio
@@ -48,6 +52,12 @@ static inline const u32 *of_get_address(struct device_node *dev, int index,
 {
 	return NULL;
 }
+
+static inline void of_parse_dma_window(struct device_node *dn,
+		       const void *dma_window_prop, unsigned long *busno,
+			       unsigned long *phys, unsigned long *size)
+{
+}
 #endif /* CONFIG_OF_ADDRESS */
 
 
-- 
1.7.5.4