From: Thierry Reding <[email protected]>
Subject: Re: [PATCH 1/1] dt: Add general DMA window parser
Date: Wed, 18 Apr 2012 12:26:29 +0200
Message-ID: <[email protected]>

> * PGP Signed by an unknown key
> 
> * Hiroshi Doyu wrote:
> > +   cells = prop ? *(__be32 *)prop : of_n_addr_cells(dn);
> 
> I think this needs to be:
> 
>       cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
> 
> Only casting isn't enough, you need the bytes to be swapped.

Right. Try again. Sorry for spamming.

>From 1ee8a9b3a839456b170af74b11a4304bfda965c4 Mon Sep 17 00:00:00 2001
From: Hiroshi DOYU <[email protected]>
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 <[email protected]>
---
 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..45c9e88
--- /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_to_cpup(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_to_cpup(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
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