diff options
| author | Hein Tibosch <hein_tibosch@yahoo.es> | 2012-10-25 13:38:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-25 14:37:53 -0700 |
| commit | d5ea7b5ec1ee4dac868143806c0bd94855754677 (patch) | |
| tree | e0f1a0677b0cd27392bce3c8fec7e5ca1075f156 | |
| parent | 35cfa2b0b491c37e23527822bf365610dbb188e5 (diff) | |
drivers/dma/dw_dmac: make driver's endianness configurable
The dw_dmac driver was originally developed for avr32 to be used with the
Synopsys DesignWare AHB DMA controller. Starting from 2.6.38, access to
the device's i/o memory was done with the little-endian readl/writel
functions(1)
This broke the driver for the avr32 platform, because it needs big
(native) endian accessors. This patch makes the endianness configurable
using 'DW_DMAC_BIG_ENDIAN_IO', which will default be true for AVR32
I submitted this patch before(2) but then waited for Andy to finish other
changes to the same module(3).
(1) https://patchwork.kernel.org/patch/608211
(2) https://lkml.org/lkml/2012/8/26/148
(3) https://lkml.org/lkml/2012/9/21/173
Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: Havard Skinnemoen <havard@skinnemoen.net>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/dma/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/dma/dw_dmac_regs.h | 18 |
2 files changed, 24 insertions, 5 deletions
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 677cd6e4e1a1..d4c12180c654 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -90,6 +90,17 @@ config DW_DMAC Support the Synopsys DesignWare AHB DMA controller. This can be integrated in chips such as the Atmel AT32ap7000. +config DW_DMAC_BIG_ENDIAN_IO + bool "Use big endian I/O register access" + default y if AVR32 + depends on DW_DMAC + help + Say yes here to use big endian I/O access when reading and writing + to the DMA controller registers. This is needed on some platforms, + like the Atmel AVR32 architecture. + + If unsure, use the default setting. + 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 ff39fa6cd2bc..88965597b7d0 100644 --- a/drivers/dma/dw_dmac_regs.h +++ b/drivers/dma/dw_dmac_regs.h @@ -98,9 +98,17 @@ struct dw_dma_regs { u32 DW_PARAMS; }; +#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO +#define dma_readl_native ioread32be +#define dma_writel_native iowrite32be +#else +#define dma_readl_native readl +#define dma_writel_native writel +#endif + /* To access the registers in early stage of probe */ #define dma_read_byaddr(addr, name) \ - readl((addr) + offsetof(struct dw_dma_regs, name)) + dma_readl_native((addr) + offsetof(struct dw_dma_regs, name)) /* Bitfields in DW_PARAMS */ #define DW_PARAMS_NR_CHAN 8 /* number of channels */ @@ -216,9 +224,9 @@ __dwc_regs(struct dw_dma_chan *dwc) } #define channel_readl(dwc, name) \ - readl(&(__dwc_regs(dwc)->name)) + dma_readl_native(&(__dwc_regs(dwc)->name)) #define channel_writel(dwc, name, val) \ - writel((val), &(__dwc_regs(dwc)->name)) + dma_writel_native((val), &(__dwc_regs(dwc)->name)) static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan) { @@ -246,9 +254,9 @@ static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw) } #define dma_readl(dw, name) \ - readl(&(__dw_regs(dw)->name)) + dma_readl_native(&(__dw_regs(dw)->name)) #define dma_writel(dw, name, val) \ - writel((val), &(__dw_regs(dw)->name)) + dma_writel_native((val), &(__dw_regs(dw)->name)) #define channel_set_bit(dw, reg, mask) \ dma_writel(dw, reg, ((mask) << 8) | (mask)) |