From: Hein Tibosch <hein_tibosch@yahoo.es>
To: Andrew Morton <akpm@linux-foundation.org>,
viresh kumar <viresh.kumar@linaro.org>,
Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"ludovic.desroches" <ludovic.desroches@atmel.com>,
Havard Skinnemoen <havard@skinnemoen.net>,
Nicolas Ferre <nicolas.ferre@atmel.com>,
spear-devel <spear-devel@list.st.com>
Subject: [PATCH v4 1/3] dw_dmac: make driver endianness configurable
Date: Mon, 03 Sep 2012 01:52:56 +0800 [thread overview]
Message-ID: <50439CF8.3090406@yahoo.es> (raw)
From: Hein Tibosch <hein_tibosch@yahoo.es>
v4: now based and tested on 3.6-rc4
The dw_dmac was originally developed for avr32 to be used with the Synopsys
DesignWare AHB DMA controller. After 2.6.38, access to the device's i/o
memory was done with the little-endian readl/writel functions
(https://patchwork.kernel.org/patch/608211)
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_BIG_ENDIAN_IO',
which will default be true for AVR32
Signed-off-by: Hein Tibosch <hein_tibosch@yahoo.es>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd.bergmann@linaro.org>
Reviewed-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
---
drivers/dma/Kconfig | 11 +++++++++++
drivers/dma/dw_dmac_regs.h | 14 ++++++++++++++
2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index d06ea29..5a26d46 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 50830be..8aad868 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -175,10 +175,17 @@ __dwc_regs(struct dw_dma_chan *dwc)
return dwc->ch_regs;
}
+#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO
+#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)
{
@@ -201,10 +208,17 @@ static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
return dw->regs;
}
+#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO
+#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))
--
1.7.8.0
reply other threads:[~2012-09-02 18:49 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50439CF8.3090406@yahoo.es \
--to=hein_tibosch@yahoo.es \
--cc=akpm@linux-foundation.org \
--cc=arnd.bergmann@linaro.org \
--cc=egtvedt@samfundet.no \
--cc=havard@skinnemoen.net \
--cc=linux-kernel@vger.kernel.org \
--cc=ludovic.desroches@atmel.com \
--cc=nicolas.ferre@atmel.com \
--cc=spear-devel@list.st.com \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).