[PATCH 1/2] dw_dmac: make driver endianness configurable

From: Hein Tibosch
Date: Sun Aug 26 2012 - 18:29:47 EST


The dw_dmac was originally developed for avr32 to be used with the
Synopsys DesignWare AHB DMA controller. After 2.6.38, device access was done
with the little-endian readl/writel functions. This didn't work on the
avr32 platform, because it needs native-endian (i.e. big-endian) accessors.
This patch makes the endianness configurable using 'DW_DMAC_BE',
which will default be true for AVR32


Signed-off-by: Hein Tibosch <hein_tibosch@xxxxxxxx>
---
drivers/dma/Kconfig | 8 ++++++++
drivers/dma/dw_dmac_regs.h | 23 +++++++++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index aadeb5b..3635daf 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -89,6 +89,14 @@ config DW_DMAC
Support the Synopsys DesignWare AHB DMA controller. This
can be integrated in chips such as the Atmel AT32ap7000.

+config DW_DMAC_BE
+ bool "Synopsys DesignWare AHB DMA needs big endian access"
+ default y if AVR32
+ depends on DW_DMAC
+ help
+ Say yes if access to the Synopsys DesignWare AHB DMA controller
+ should be big endian, such as for Atmel AT32ap7000
+
config AT_HDMAC
tristate "Atmel AHB DMA support"
depends on ARCH_AT91
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index f298f69..cf048c3 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -175,11 +175,22 @@ __dwc_regs(struct dw_dma_chan *dwc)
return dwc->ch_regs;
}

+#ifdef CONFIG_DW_DMAC_BE
+
+#define channel_readl(dwc, name) \
+ ioread32be(&(__dwc_regs(dwc)->name))
+#define channel_writel(dwc, name, val) \
+ iowrite32be((val), &(__dwc_regs(dwc)->name))
+
+#else
+
#define channel_readl(dwc, name) \
readl(&(__dwc_regs(dwc)->name))
#define channel_writel(dwc, name, val) \
writel((val), &(__dwc_regs(dwc)->name))

+#endif
+
static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
{
return container_of(chan, struct dw_dma_chan, chan);
@@ -201,11 +212,23 @@ static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
return dw->regs;
}

+#ifdef CONFIG_DW_DMAC_BE
+
+#define dma_readl(dwc, name) \
+ ioread32be(&(__dw_regs(dw)->name))
+#define dma_writel(dwc, name, val) \
+ iowrite32be((val), &(__dw_regs(dw)->name))
+
+#else
+
#define dma_readl(dw, name) \
readl(&(__dw_regs(dw)->name))
#define dma_writel(dw, name, val) \
writel((val), &(__dw_regs(dw)->name))

+#endif
+
#define channel_set_bit(dw, reg, mask) \
dma_writel(dw, reg, ((mask) << 8) | (mask))
#define channel_clear_bit(dw, reg, mask) \
--
1.7.8.0

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