linux-kernel - [PATCH RFC 2/2] ARM: pxa: transition to dmaengine phase 1

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Message-Id: <1423954053-21760-3-git-send-email-robert.jarzmik@free.fr>
Date:	Sat, 14 Feb 2015 23:47:33 +0100
From:	Robert Jarzmik <robert.jarzmik@...e.fr>
To:	Vinod Koul <vinod.koul@...el.com>, Arnd Bergmann <arnd@...db.de>,
	Olof Johansson <olof@...om.net>,
	Daniel Mack <zonque@...il.com>,
	Haojian Zhuang <haojian.zhuang@...il.com>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	dmaengine@...r.kernel.org, Robert Jarzmik <robert.jarzmik@...e.fr>
Subject: [PATCH RFC 2/2] ARM: pxa: transition to dmaengine phase 1

In order to slowly transition pxa to dmaengine, the legacy code will now
rely on dmaengine to request a channel.

This implies that PXA architecture selects DMADEVICES and MMP_PDMA,
which is not pretty. Yet it enables PXA drivers to be ported one by one,
with part of them using dmaengine, and the other part using the legacy
code.

Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
---
 arch/arm/Kconfig                     | 2 ++
 arch/arm/plat-pxa/dma.c              | 4 +++-
 arch/arm/plat-pxa/include/plat/dma.h | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bb358d2..cc23f2b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -617,10 +617,12 @@ config ARCH_PXA
 	select CLKDEV_LOOKUP
 	select CLKSRC_MMIO
 	select CLKSRC_OF
+	select DMADEVICES
 	select GENERIC_CLOCKEVENTS
 	select GPIO_PXA
 	select HAVE_IDE
 	select IRQ_DOMAIN
+	select MMP_PDMA
 	select MULTI_IRQ_HANDLER
 	select PLAT_PXA
 	select SPARSE_IRQ
diff --git a/arch/arm/plat-pxa/dma.c b/arch/arm/plat-pxa/dma.c
index 054fc5a..e5094a6 100644
--- a/arch/arm/plat-pxa/dma.c
+++ b/arch/arm/plat-pxa/dma.c
@@ -294,7 +294,8 @@ int pxa_request_dma (char *name, pxa_dma_prio prio,
 		/* try grabbing a DMA channel with the requested priority */
 		for (i = 0; i < num_dma_channels; i++) {
 			if ((dma_channels[i].prio == prio) &&
-			    !dma_channels[i].name) {
+			    !dma_channels[i].name &&
+			    !mmp_pdma_toggle_reserved_channel(i)) {
 				found = 1;
 				break;
 			}
@@ -331,6 +332,7 @@ void pxa_free_dma (int dma_ch)
 	local_irq_save(flags);
 	DCSR(dma_ch) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
 	dma_channels[dma_ch].name = NULL;
+	mmp_pdma_toggle_reserved_channel(dma_ch);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(pxa_free_dma);
diff --git a/arch/arm/plat-pxa/include/plat/dma.h b/arch/arm/plat-pxa/include/plat/dma.h
index a7b91dc..f4c6339 100644
--- a/arch/arm/plat-pxa/include/plat/dma.h
+++ b/arch/arm/plat-pxa/include/plat/dma.h
@@ -81,5 +81,6 @@ int pxa_request_dma (char *name,
 			 void *data);
 
 void pxa_free_dma (int dma_ch);
+extern int mmp_pdma_toggle_reserved_channel(int legacy_channel);
 
 #endif /* __PLAT_DMA_H */
-- 
2.1.0

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