Commit 1ec1e82f authored by Sascha Hauer's avatar Sascha Hauer Committed by Dan Williams
Browse files

dmaengine: Add Freescale i.MX SDMA support 



This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented
as a seperate coprocessor. SDMA needs its own firmware which is
requested using the standard request_firmware mechanism. The firmware
has different entry points for each peripheral type, so drivers
have to pass the peripheral type to the DMA engine which in turn
picks the correct firmware entry point from a table contained in
the firmware image itself.
The original Freescale code also supports support for transfering
data to the internal SRAM which needs different entry points to
the firmware. Support for this is currently not implemented. Also,
support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only
a single descriptor is statically assigned to a each channel. This
means that transfers can't be queued up but only a single transfer
is in progress. This simplifies implementation a lot and is sufficient
for the usual device/memory transfers.

Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: default avatarLinus Walleij <linus.ml.walleij@gmail.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 6e3ecaf0

arch/arm/mach-imx/include/mach/dma-v1.h

+2 −6
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ 


#define imx_has_dma_v1()	(cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())



#include <mach/dma.h>



#define IMX_DMA_CHANNELS  16



#define DMA_MODE_READ		0
@@ -96,12 +98,6 @@ int imx_dma_request(int channel, const char *name); 


void imx_dma_free(int channel);



enum imx_dma_prio {

	DMA_PRIO_HIGH = 0,

	DMA_PRIO_MEDIUM = 1,

	DMA_PRIO_LOW = 2

};



int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio);



#endif	/* __MACH_DMA_V1_H__ */

arch/arm/plat-mxc/include/mach/dma.h

0 → 100644
+67 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2004-2009 Freescale Semiconductor, Inc. All Rights Reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#ifndef __ASM_ARCH_MXC_DMA_H__

#define __ASM_ARCH_MXC_DMA_H__



#include <linux/scatterlist.h>

#include <linux/device.h>

#include <linux/dmaengine.h>



/*

 * This enumerates peripheral types. Used for SDMA.

 */

enum sdma_peripheral_type {

	IMX_DMATYPE_SSI,	/* MCU domain SSI */

	IMX_DMATYPE_SSI_SP,	/* Shared SSI */

	IMX_DMATYPE_MMC,	/* MMC */

	IMX_DMATYPE_SDHC,	/* SDHC */

	IMX_DMATYPE_UART,	/* MCU domain UART */

	IMX_DMATYPE_UART_SP,	/* Shared UART */

	IMX_DMATYPE_FIRI,	/* FIRI */

	IMX_DMATYPE_CSPI,	/* MCU domain CSPI */

	IMX_DMATYPE_CSPI_SP,	/* Shared CSPI */

	IMX_DMATYPE_SIM,	/* SIM */

	IMX_DMATYPE_ATA,	/* ATA */

	IMX_DMATYPE_CCM,	/* CCM */

	IMX_DMATYPE_EXT,	/* External peripheral */

	IMX_DMATYPE_MSHC,	/* Memory Stick Host Controller */

	IMX_DMATYPE_MSHC_SP,	/* Shared Memory Stick Host Controller */

	IMX_DMATYPE_DSP,	/* DSP */

	IMX_DMATYPE_MEMORY,	/* Memory */

	IMX_DMATYPE_FIFO_MEMORY,/* FIFO type Memory */

	IMX_DMATYPE_SPDIF,	/* SPDIF */

	IMX_DMATYPE_IPU_MEMORY,	/* IPU Memory */

	IMX_DMATYPE_ASRC,	/* ASRC */

	IMX_DMATYPE_ESAI,	/* ESAI */

};



enum imx_dma_prio {

	DMA_PRIO_HIGH = 0,

	DMA_PRIO_MEDIUM = 1,

	DMA_PRIO_LOW = 2

};



struct imx_dma_data {

	int dma_request; /* DMA request line */

	enum sdma_peripheral_type peripheral_type;

	int priority;

};



static inline int imx_dma_is_ipu(struct dma_chan *chan)

{

	return !strcmp(dev_name(chan->device->dev), "ipu-core");

}



static inline int imx_dma_is_general_purpose(struct dma_chan *chan)

{

	return !strcmp(dev_name(chan->device->dev), "imx-sdma") ||

		!strcmp(dev_name(chan->device->dev), "imx-dma");

}



#endif

arch/arm/plat-mxc/include/mach/sdma.h

0 → 100644
+17 −0
Original line number Diff line number Diff line 
#ifndef __MACH_MXC_SDMA_H__

#define __MACH_MXC_SDMA_H__



/**

 * struct sdma_platform_data - platform specific data for SDMA engine

 *

 * @sdma_version	The version of this SDMA engine

 * @cpu_name		used to generate the firmware name

 * @to_version		CPU Tape out version

 */

struct sdma_platform_data {

	int sdma_version;

	char *cpu_name;

	int to_version;

};



#endif /* __MACH_MXC_SDMA_H__ */

drivers/dma/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -195,6 +195,14 @@ config PCH_DMA 
	help

	  Enable support for the Topcliff PCH DMA engine.



config IMX_SDMA

	tristate "i.MX SDMA support"

	depends on ARCH_MX25 || ARCH_MX3 || ARCH_MX5

	select DMA_ENGINE

	help

	  Support the i.MX SDMA engine. This engine is integrated into

	  Freescale i.MX25/31/35/51 chips.



config DMA_ENGINE

	bool

drivers/dma/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o 
obj-$(CONFIG_SH_DMAE) += shdma.o

obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o

obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/

obj-$(CONFIG_IMX_SDMA) += imx-sdma.o

obj-$(CONFIG_TIMB_DMA) += timb_dma.o

obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o

obj-$(CONFIG_PL330_DMA) += pl330.o

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