Subject: [PATCHv11 2/2] dma: Add Freescale eDMA engine driver support

From: [email-masked] (Vinod Koul)
Date: Mon, 17 Feb 2014 23:17:48 +0530

On Mon, Jan 20, 2014 at 05:23:51PM +0800, Jingchang Lu wrote:
> Add Freescale enhanced direct memory(eDMA) controller support.
> This module can be found on Vybrid and LS-1 SoCs.
> 
> Signed-off-by: Alison Wang <[email-masked]>
> Signed-off-by: Jingchang Lu <[email-masked]>
> Acked-by: Arnd Bergmann <[email-masked]>

Where is the 1/2 in this patch series, I cant find it in archives as well

Also please post to dmaengine at vger.kernel.org

-- 
~Vinod

> ---
> changes in v11:
>  Add dma device_slave_caps definition.
> 
> changes in v10:
>  define fsl_edma_mutex in fsl_edma_engine instead of global.
>  minor changes of binding description.
> 
> changes in v9:
>  define endian's operating functions instead of macro definition.
>  remove the filter function, using dma_get_slave_channel instead.
> 
> changes in v8:
>  change the edma driver according eDMA dts change.
>  add big-endian and little-endian handling.
> 
>  no changes in v4 ~ v7.
> 
>  changes in v3:
>   add vf610 edma dt-bindings namespace with prefix VF610_*.
> 
>  changes in v2:
>   using generic dma-channels property instead of fsl,dma-channels.
> 
>  Documentation/devicetree/bindings/dma/fsl-edma.txt |  76 ++
>  drivers/dma/Kconfig                                |  10 +
>  drivers/dma/Makefile                               |   1 +
>  drivers/dma/fsl-edma.c                             | 975 +++++++++++++++++++++
>  4 files changed, 1062 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/fsl-edma.txt
>  create mode 100644 drivers/dma/fsl-edma.c
> 
> diff --git a/Documentation/devicetree/bindings/dma/fsl-edma.txt b/Documentation/devicetree/bindings/dma/fsl-edma.txt
> new file mode 100644
> index 0000000..191d7bd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/fsl-edma.txt
> @@ -0,0 +1,76 @@
> +* Freescale enhanced Direct Memory Access(eDMA) Controller
> +
> +  The eDMA channels have multiplex capability by programmble memory-mapped
> +registers. channels are split into two groups, called DMAMUX0 and DMAMUX1,
> +specific DMA request source can only be multiplexed by any channel of certain
> +group, DMAMUX0 or DMAMUX1, but not both.
> +
> +* eDMA Controller
> +Required properties:
> +- compatible :
> +	- "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC
> +- reg : Specifies base physical address(s) and size of the eDMA registers.
> +	The 1st region is eDMA control register's address and size.
> +	The 2nd and the 3rd regions are programmable channel multiplexing
> +	control register's address and size.
> +- interrupts : A list of interrupt-specifiers, one for each entry in
> +	interrupt-names.
> +- interrupt-names : Should contain:
> +	"edma-tx" - the transmission interrupt
> +	"edma-err" - the error interrupt
> +- #dma-cells : Must be <2>.
> +	The 1st cell specifies the DMAMUX(0 for DMAMUX0 and 1 for DMAMUX1).
> +	Specific request source can only be multiplexed by specific channels
> +	group called DMAMUX.
> +	The 2nd cell specifies the request source(slot) ID.
> +	See the SoC's reference manual for all the supported request sources.
> +- dma-channels : Number of channels supported by the controller
> +- clock-names : A list of channel group clock names. Should contain:
> +	"dmamux0" - clock name of mux0 group
> +	"dmamux1" - clock name of mux1 group
> +- clocks : A list of phandle and clock-specifier pairs, one for each entry in
> +	clock-names.
> +
> +Optional properties:
> +- big-endian: If present registers and hardware scatter/gather descriptors
> +	of the eDMA are implemented in big endian mode, otherwise in little
> +	mode.
> +
> +
> +Examples:
> +
> +edma0: dma-controller at 40018000 {
> +	#dma-cells = <2>;
> +	compatible = "fsl,vf610-edma";
> +	reg = <0x40018000 0x2000>,
> +		<0x40024000 0x1000>,
> +		<0x40025000 0x1000>;
> +	interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>,
> +		<0 9 IRQ_TYPE_LEVEL_HIGH>;
> +	interrupt-names = "edma-tx", "edma-err";
> +	dma-channels = <32>;
> +	clock-names = "dmamux0", "dmamux1";
> +	clocks = <&clks VF610_CLK_DMAMUX0>,
> +		<&clks VF610_CLK_DMAMUX1>;
> +};
> +
> +
> +* DMA clients
> +DMA client drivers that uses the DMA function must use the format described
> +in the dma.txt file, using a two-cell specifier for each channel: the 1st
> +specifies the channel group(DMAMUX) in which this request can be multiplexed,
> +and the 2nd specifies the request source.
> +
> +Examples:
> +
> +sai2: sai at 40031000 {
> +	compatible = "fsl,vf610-sai";
> +	reg = <0x40031000 0x1000>;
> +	interrupts = <0 86 IRQ_TYPE_LEVEL_HIGH>;
> +	clock-names = "sai";
> +	clocks = <&clks VF610_CLK_SAI2>;
> +	dma-names = "tx", "rx";
> +	dmas = <&edma0 0 21>,
> +		<&edma0 0 20>;
> +	status = "disabled";
> +};
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 9ae6f54..3d8a522 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -342,6 +342,16 @@ config K3_DMA
>  	  Support the DMA engine for Hisilicon K3 platform
>  	  devices.
>  
> +config FSL_EDMA
> +	tristate "Freescale eDMA engine support"
> +	depends on OF
> +	select DMA_ENGINE
> +	select DMA_VIRTUAL_CHANNELS
> +	help
> +	  Support the Freescale eDMA engine with programmable channel
> +	  multiplexing capability for DMA request sources(slot).
> +	  This module can be found on Freescale Vybrid and LS-1 SoCs.
> +
>  config DMA_ENGINE
>  	bool
>  
> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index 0a6f08e..e39c56b 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -43,3 +43,4 @@ obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
>  obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
>  obj-$(CONFIG_TI_CPPI41) += cppi41.o
>  obj-$(CONFIG_K3_DMA) += k3dma.o
> +obj-$(CONFIG_FSL_EDMA) += fsl-edma.o
> diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
> new file mode 100644
> index 0000000..9025300
> --- /dev/null
> +++ b/drivers/dma/fsl-edma.c
> @@ -0,0 +1,975 @@
> +/*
> + * drivers/dma/fsl-edma.c
> + *
> + * Copyright 2013-2014 Freescale Semiconductor, Inc.
> + *
> + * Driver for the Freescale eDMA engine with flexible channel multiplexing
> + * capability for DMA request sources. The eDMA block can be found on some
> + * Vybrid and Layerscape SoCs.
> + *
> + * This program is free software; you can redistribute  it and/or modify it
> + * under  the terms of  the GNU General  Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dmapool.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_dma.h>
> +
> +#include "virt-dma.h"
> +
> +#define EDMA_CR			0x00
> +#define EDMA_ES			0x04
> +#define EDMA_ERQ		0x0C
> +#define EDMA_EEI		0x14
> +#define EDMA_SERQ		0x1B
> +#define EDMA_CERQ		0x1A
> +#define EDMA_SEEI		0x19
> +#define EDMA_CEEI		0x18
> +#define EDMA_CINT		0x1F
> +#define EDMA_CERR		0x1E
> +#define EDMA_SSRT		0x1D
> +#define EDMA_CDNE		0x1C
> +#define EDMA_INTR		0x24
> +#define EDMA_ERR		0x2C
> +
> +#define EDMA_TCD_SADDR(x)	(0x1000 + 32 * (x))
> +#define EDMA_TCD_SOFF(x)	(0x1004 + 32 * (x))
> +#define EDMA_TCD_ATTR(x)	(0x1006 + 32 * (x))
> +#define EDMA_TCD_NBYTES(x)	(0x1008 + 32 * (x))
> +#define EDMA_TCD_SLAST(x)	(0x100C + 32 * (x))
> +#define EDMA_TCD_DADDR(x)	(0x1010 + 32 * (x))
> +#define EDMA_TCD_DOFF(x)	(0x1014 + 32 * (x))
> +#define EDMA_TCD_CITER_ELINK(x)	(0x1016 + 32 * (x))
> +#define EDMA_TCD_CITER(x)	(0x1016 + 32 * (x))
> +#define EDMA_TCD_DLAST_SGA(x)	(0x1018 + 32 * (x))
> +#define EDMA_TCD_CSR(x)		(0x101C + 32 * (x))
> +#define EDMA_TCD_BITER_ELINK(x)	(0x101E + 32 * (x))
> +#define EDMA_TCD_BITER(x)	(0x101E + 32 * (x))
> +
> +#define EDMA_CR_EDBG		BIT(1)
> +#define EDMA_CR_ERCA		BIT(2)
> +#define EDMA_CR_ERGA		BIT(3)
> +#define EDMA_CR_HOE		BIT(4)
> +#define EDMA_CR_HALT		BIT(5)
> +#define EDMA_CR_CLM		BIT(6)
> +#define EDMA_CR_EMLM		BIT(7)
> +#define EDMA_CR_ECX		BIT(16)
> +#define EDMA_CR_CX		BIT(17)
> +
> +#define EDMA_SEEI_SEEI(x)	((x) & 0x1F)
> +#define EDMA_CEEI_CEEI(x)	((x) & 0x1F)
> +#define EDMA_CINT_CINT(x)	((x) & 0x1F)
> +#define EDMA_CERR_CERR(x)	((x) & 0x1F)
> +
> +#define EDMA_TCD_ATTR_DSIZE(x)		(((x) & 0x0007))
> +#define EDMA_TCD_ATTR_DMOD(x)		(((x) & 0x001F) << 3)
> +#define EDMA_TCD_ATTR_SSIZE(x)		(((x) & 0x0007) << 8)
> +#define EDMA_TCD_ATTR_SMOD(x)		(((x) & 0x001F) << 11)
> +#define EDMA_TCD_ATTR_SSIZE_8BIT	(0x0000)
> +#define EDMA_TCD_ATTR_SSIZE_16BIT	(0x0100)
> +#define EDMA_TCD_ATTR_SSIZE_32BIT	(0x0200)
> +#define EDMA_TCD_ATTR_SSIZE_64BIT	(0x0300)
> +#define EDMA_TCD_ATTR_SSIZE_32BYTE	(0x0500)
> +#define EDMA_TCD_ATTR_DSIZE_8BIT	(0x0000)
> +#define EDMA_TCD_ATTR_DSIZE_16BIT	(0x0001)
> +#define EDMA_TCD_ATTR_DSIZE_32BIT	(0x0002)
> +#define EDMA_TCD_ATTR_DSIZE_64BIT	(0x0003)
> +#define EDMA_TCD_ATTR_DSIZE_32BYTE	(0x0005)
> +
> +#define EDMA_TCD_SOFF_SOFF(x)		(x)
> +#define EDMA_TCD_NBYTES_NBYTES(x)	(x)
> +#define EDMA_TCD_SLAST_SLAST(x)		(x)
> +#define EDMA_TCD_DADDR_DADDR(x)		(x)
> +#define EDMA_TCD_CITER_CITER(x)		((x) & 0x7FFF)
> +#define EDMA_TCD_DOFF_DOFF(x)		(x)
> +#define EDMA_TCD_DLAST_SGA_DLAST_SGA(x)	(x)
> +#define EDMA_TCD_BITER_BITER(x)		((x) & 0x7FFF)
> +
> +#define EDMA_TCD_CSR_START		BIT(0)
> +#define EDMA_TCD_CSR_INT_MAJOR		BIT(1)
> +#define EDMA_TCD_CSR_INT_HALF		BIT(2)
> +#define EDMA_TCD_CSR_D_REQ		BIT(3)
> +#define EDMA_TCD_CSR_E_SG		BIT(4)
> +#define EDMA_TCD_CSR_E_LINK		BIT(5)
> +#define EDMA_TCD_CSR_ACTIVE		BIT(6)
> +#define EDMA_TCD_CSR_DONE		BIT(7)
> +
> +#define EDMAMUX_CHCFG_DIS		0x0
> +#define EDMAMUX_CHCFG_ENBL		0x80
> +#define EDMAMUX_CHCFG_SOURCE(n)		((n) & 0x3F)
> +
> +#define DMAMUX_NR	2
> +
> +#define FSL_EDMA_BUSWIDTHS	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
> +				BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
> +				BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
> +				BIT(DMA_SLAVE_BUSWIDTH_8_BYTES)
> +
> +struct fsl_edma_hw_tcd {
> +	u32	saddr;
> +	u16	soff;
> +	u16	attr;
> +	u32	nbytes;
> +	u32	slast;
> +	u32	daddr;
> +	u16	doff;
> +	u16	citer;
> +	u32	dlast_sga;
> +	u16	csr;
> +	u16	biter;
> +};
> +
> +struct fsl_edma_sw_tcd {
> +	dma_addr_t			ptcd;
> +	struct fsl_edma_hw_tcd		*vtcd;
> +};
> +
> +struct fsl_edma_slave_config {
> +	enum dma_transfer_direction	dir;
> +	enum dma_slave_buswidth		addr_width;
> +	u32				dev_addr;
> +	u32				burst;
> +	u32				attr;
> +};
> +
> +struct fsl_edma_chan {
> +	struct virt_dma_chan		vchan;
> +	enum dma_status			status;
> +	struct fsl_edma_engine		*edma;
> +	struct fsl_edma_desc		*edesc;
> +	struct fsl_edma_slave_config	fsc;
> +	struct dma_pool			*tcd_pool;
> +};
> +
> +struct fsl_edma_desc {
> +	struct virt_dma_desc		vdesc;
> +	struct fsl_edma_chan		*echan;
> +	bool				iscyclic;
> +	unsigned int			n_tcds;
> +	struct fsl_edma_sw_tcd		tcd[];
> +};
> +
> +struct fsl_edma_engine {
> +	struct dma_device	dma_dev;
> +	void __iomem		*membase;
> +	void __iomem		*muxbase[DMAMUX_NR];
> +	struct clk		*muxclk[DMAMUX_NR];
> +	struct mutex		fsl_edma_mutex;
> +	u32			n_chans;
> +	int			txirq;
> +	int			errirq;
> +	bool			big_endian;
> +	struct fsl_edma_chan	chans[];
> +};
> +
> +/*
> + * R/W functions for big- or little-endian registers
> + * the eDMA controller's endian is independent of the CPU core's endian.
> + */
> +
> +static u16 edma_readw(struct fsl_edma_engine *edma, void __iomem *addr)
> +{
> +	if (edma->big_endian)
> +		return ioread16be(addr);
> +	else
> +		return ioread16(addr);
> +}
> +
> +static u32 edma_readl(struct fsl_edma_engine *edma, void __iomem *addr)
> +{
> +	if (edma->big_endian)
> +		return ioread32be(addr);
> +	else
> +		return ioread32(addr);
> +}
> +
> +static void edma_writeb(struct fsl_edma_engine *edma, u8 val, void __iomem *addr)
> +{
> +	iowrite8(val, addr);
> +}
> +
> +static void edma_writew(struct fsl_edma_engine *edma, u16 val, void __iomem *addr)
> +{
> +	if (edma->big_endian)
> +		iowrite16be(val, addr);
> +	else
> +		iowrite16(val, addr);
> +}
> +
> +static void edma_writel(struct fsl_edma_engine *edma, u32 val, void __iomem *addr)
> +{
> +	if (edma->big_endian)
> +		iowrite32be(val, addr);
> +	else
> +		iowrite32(val, addr);
> +}
> +
> +static struct fsl_edma_chan *to_fsl_edma_chan(struct dma_chan *chan)
> +{
> +	return container_of(chan, struct fsl_edma_chan, vchan.chan);
> +}
> +
> +static struct fsl_edma_desc *to_fsl_edma_desc(struct virt_dma_desc *vd)
> +{
> +	return container_of(vd, struct fsl_edma_desc, vdesc);
> +}
> +
> +static void fsl_edma_enable_request(struct fsl_edma_chan *fsl_chan)
> +{
> +	void __iomem *addr = fsl_chan->edma->membase;
> +	u32 ch = fsl_chan->vchan.chan.chan_id;
> +
> +	edma_writeb(fsl_chan->edma, EDMA_SEEI_SEEI(ch), addr + EDMA_SEEI);
> +	edma_writeb(fsl_chan->edma, ch, addr + EDMA_SERQ);
> +}
> +
> +static void fsl_edma_disable_request(struct fsl_edma_chan *fsl_chan)
> +{
> +	void __iomem *addr = fsl_chan->edma->membase;
> +	u32 ch = fsl_chan->vchan.chan.chan_id;
> +
> +	edma_writeb(fsl_chan->edma, ch, addr + EDMA_CERQ);
> +	edma_writeb(fsl_chan->edma, EDMA_CEEI_CEEI(ch), addr + EDMA_CEEI);
> +}
> +
> +static void fsl_edma_chan_mux(struct fsl_edma_chan *fsl_chan,
> +			unsigned int slot, bool enable)
> +{
> +	u32 ch = fsl_chan->vchan.chan.chan_id;
> +	void __iomem *muxaddr = fsl_chan->edma->muxbase[ch / DMAMUX_NR];
> +	unsigned chans_per_mux, ch_off;
> +
> +	chans_per_mux = fsl_chan->edma->n_chans / DMAMUX_NR;
> +	ch_off = fsl_chan->vchan.chan.chan_id % chans_per_mux;
> +
> +	if (enable)
> +		edma_writeb(fsl_chan->edma,
> +				EDMAMUX_CHCFG_ENBL | EDMAMUX_CHCFG_SOURCE(slot),
> +				muxaddr + ch_off);
> +	else
> +		edma_writeb(fsl_chan->edma, EDMAMUX_CHCFG_DIS, muxaddr + ch_off);
> +}
> +
> +static unsigned int fsl_edma_get_tcd_attr(enum dma_slave_buswidth addr_width)
> +{
> +	switch (addr_width) {
> +	case 1:
> +		return EDMA_TCD_ATTR_SSIZE_8BIT | EDMA_TCD_ATTR_DSIZE_8BIT;
> +	case 2:
> +		return EDMA_TCD_ATTR_SSIZE_16BIT | EDMA_TCD_ATTR_DSIZE_16BIT;
> +	case 4:
> +		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
> +	case 8:
> +		return EDMA_TCD_ATTR_SSIZE_64BIT | EDMA_TCD_ATTR_DSIZE_64BIT;
> +	default:
> +		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
> +	}
> +}
> +
> +static void fsl_edma_free_desc(struct virt_dma_desc *vdesc)
> +{
> +	struct fsl_edma_desc *fsl_desc;
> +	int i;
> +
> +	fsl_desc = to_fsl_edma_desc(vdesc);
> +	for (i = 0; i < fsl_desc->n_tcds; i++)
> +			dma_pool_free(fsl_desc->echan->tcd_pool,
> +					fsl_desc->tcd[i].vtcd,
> +					fsl_desc->tcd[i].ptcd);
> +	kfree(fsl_desc);
> +}
> +
> +static int fsl_edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
> +		unsigned long arg)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	struct dma_slave_config *cfg = (void *)arg;
> +	unsigned long flags;
> +	LIST_HEAD(head);
> +
> +	switch (cmd) {
> +	case DMA_TERMINATE_ALL:
> +		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +		fsl_edma_disable_request(fsl_chan);
> +		fsl_chan->edesc = NULL;
> +		vchan_get_all_descriptors(&fsl_chan->vchan, &head);
> +		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +		vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
> +		return 0;
> +
> +	case DMA_SLAVE_CONFIG:
> +		fsl_chan->fsc.dir = cfg->direction;
> +		if (cfg->direction == DMA_DEV_TO_MEM) {
> +			fsl_chan->fsc.dev_addr = cfg->src_addr;
> +			fsl_chan->fsc.addr_width = cfg->src_addr_width;
> +			fsl_chan->fsc.burst = cfg->src_maxburst;
> +			fsl_chan->fsc.attr = fsl_edma_get_tcd_attr(cfg->src_addr_width);
> +		} else if (cfg->direction == DMA_MEM_TO_DEV) {
> +			fsl_chan->fsc.dev_addr = cfg->dst_addr;
> +			fsl_chan->fsc.addr_width = cfg->dst_addr_width;
> +			fsl_chan->fsc.burst = cfg->dst_maxburst;
> +			fsl_chan->fsc.attr = fsl_edma_get_tcd_attr(cfg->dst_addr_width);
> +		} else {
> +			return -EINVAL;
> +		}
> +		return 0;
> +
> +	case DMA_PAUSE:
> +		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +		if (fsl_chan->edesc) {
> +			fsl_edma_disable_request(fsl_chan);
> +			fsl_chan->status = DMA_PAUSED;
> +		}
> +		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +		return 0;
> +
> +	case DMA_RESUME:
> +		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +		if (fsl_chan->edesc) {
> +			fsl_edma_enable_request(fsl_chan);
> +			fsl_chan->status = DMA_IN_PROGRESS;
> +		}
> +		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +		return 0;
> +
> +	default:
> +		return -ENXIO;
> +	}
> +}
> +
> +static size_t fsl_edma_desc_residue(struct fsl_edma_chan *fsl_chan,
> +		struct virt_dma_desc *vdesc, bool in_progress)
> +{
> +	struct fsl_edma_desc *edesc = fsl_chan->edesc;
> +	void __iomem *addr = fsl_chan->edma->membase;
> +	u32 ch = fsl_chan->vchan.chan.chan_id;
> +	enum dma_transfer_direction dir = fsl_chan->fsc.dir;
> +	dma_addr_t cur_addr, dma_addr;
> +	size_t len, size;
> +	int i;
> +
> +	/* calculate the total size in this desc */
> +	for (len = i = 0; i < fsl_chan->edesc->n_tcds; i++)
> +		len += edma_readl(fsl_chan->edma, &(edesc->tcd[i].vtcd->nbytes))
> +			* edma_readw(fsl_chan->edma, &(edesc->tcd[i].vtcd->biter));
> +
> +	if (!in_progress)
> +		return len;
> +
> +	if (dir == DMA_MEM_TO_DEV)
> +		cur_addr = edma_readl(fsl_chan->edma, addr + EDMA_TCD_SADDR(ch));
> +	else
> +		cur_addr = edma_readl(fsl_chan->edma, addr + EDMA_TCD_DADDR(ch));
> +
> +	/* figure out the finished and calculate the residue */
> +	for (i = 0; i < fsl_chan->edesc->n_tcds; i++) {
> +		size = edma_readl(fsl_chan->edma, &(edesc->tcd[i].vtcd->nbytes))
> +			* edma_readw(fsl_chan->edma, &(edesc->tcd[i].vtcd->biter));
> +		if (dir == DMA_MEM_TO_DEV)
> +			dma_addr = edma_readl(fsl_chan->edma,
> +					&(edesc->tcd[i].vtcd->saddr));
> +		else
> +			dma_addr = edma_readl(fsl_chan->edma,
> +					&(edesc->tcd[i].vtcd->daddr));
> +
> +		len -= size;
> +		if (cur_addr > dma_addr && cur_addr < dma_addr + size) {
> +			len += dma_addr + size - cur_addr;
> +			break;
> +		}
> +	}
> +
> +	return len;
> +}
> +
> +static enum dma_status fsl_edma_tx_status(struct dma_chan *chan,
> +		dma_cookie_t cookie, struct dma_tx_state *txstate)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	struct virt_dma_desc *vdesc;
> +	enum dma_status status;
> +	unsigned long flags;
> +
> +	status = dma_cookie_status(chan, cookie, txstate);
> +	if (status == DMA_COMPLETE)
> +		return status;
> +
> +	if (!txstate)
> +		return fsl_chan->status;
> +
> +	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +	vdesc = vchan_find_desc(&fsl_chan->vchan, cookie);
> +	if (fsl_chan->edesc && cookie == fsl_chan->edesc->vdesc.tx.cookie)
> +		txstate->residue = fsl_edma_desc_residue(fsl_chan, vdesc, true);
> +	else if (vdesc)
> +		txstate->residue = fsl_edma_desc_residue(fsl_chan, vdesc, false);
> +	else
> +		txstate->residue = 0;
> +
> +	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +
> +	return fsl_chan->status;
> +}
> +
> +static void fsl_edma_set_tcd_params(struct fsl_edma_chan *fsl_chan,
> +		u32 src, u32 dst, u16 attr, u16 soff, u32 nbytes,
> +		u32 slast, u16 citer, u16 biter, u32 doff, u32 dlast_sga,
> +		u16 csr)
> +{
> +	void __iomem *addr = fsl_chan->edma->membase;
> +	u32 ch = fsl_chan->vchan.chan.chan_id;
> +
> +	/*
> +	 * TCD parameters have been swapped in fill_tcd_params(),
> +	 * so just write them to registers in the cpu endian here
> +	 */
> +	writew(0, addr + EDMA_TCD_CSR(ch));
> +	writel(src, addr + EDMA_TCD_SADDR(ch));
> +	writel(dst, addr + EDMA_TCD_DADDR(ch));
> +	writew(attr, addr + EDMA_TCD_ATTR(ch));
> +	writew(soff, addr + EDMA_TCD_SOFF(ch));
> +	writel(nbytes, addr + EDMA_TCD_NBYTES(ch));
> +	writel(slast, addr + EDMA_TCD_SLAST(ch));
> +	writew(citer, addr + EDMA_TCD_CITER(ch));
> +	writew(biter, addr + EDMA_TCD_BITER(ch));
> +	writew(doff, addr + EDMA_TCD_DOFF(ch));
> +	writel(dlast_sga, addr + EDMA_TCD_DLAST_SGA(ch));
> +	writew(csr, addr + EDMA_TCD_CSR(ch));
> +}
> +
> +static void fill_tcd_params(struct fsl_edma_engine *edma,
> +		struct fsl_edma_hw_tcd *tcd, u32 src, u32 dst,
> +		u16 attr, u16 soff, u32 nbytes, u32 slast, u16 citer,
> +		u16 biter, u16 doff, u32 dlast_sga, bool major_int,
> +		bool disable_req, bool enable_sg)
> +{
> +	u16 csr = 0;
> +
> +	/*
> +	 * eDMA hardware SGs require the TCD parameters stored in memory
> +	 * the same endian as the eDMA module so that they can be loaded
> +	 * automatically by the engine
> +	 */
> +	edma_writel(edma, src, &(tcd->saddr));
> +	edma_writel(edma, dst, &(tcd->daddr));
> +	edma_writew(edma, attr, &(tcd->attr));
> +	edma_writew(edma, EDMA_TCD_SOFF_SOFF(soff), &(tcd->soff));
> +	edma_writel(edma, EDMA_TCD_NBYTES_NBYTES(nbytes), &(tcd->nbytes));
> +	edma_writel(edma, EDMA_TCD_SLAST_SLAST(slast), &(tcd->slast));
> +	edma_writew(edma, EDMA_TCD_CITER_CITER(citer), &(tcd->citer));
> +	edma_writew(edma, EDMA_TCD_DOFF_DOFF(doff), &(tcd->doff));
> +	edma_writel(edma, EDMA_TCD_DLAST_SGA_DLAST_SGA(dlast_sga), &(tcd->dlast_sga));
> +	edma_writew(edma, EDMA_TCD_BITER_BITER(biter), &(tcd->biter));
> +	if (major_int)
> +		csr |= EDMA_TCD_CSR_INT_MAJOR;
> +
> +	if (disable_req)
> +		csr |= EDMA_TCD_CSR_D_REQ;
> +
> +	if (enable_sg)
> +		csr |= EDMA_TCD_CSR_E_SG;
> +
> +	edma_writew(edma, csr, &(tcd->csr));
> +}
> +
> +static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan,
> +		int sg_len)
> +{
> +	struct fsl_edma_desc *fsl_desc;
> +	int i;
> +
> +	fsl_desc = kzalloc(sizeof(*fsl_desc) + sizeof(struct fsl_edma_sw_tcd) * sg_len,
> +				GFP_NOWAIT);
> +	if (!fsl_desc)
> +		return NULL;
> +
> +	fsl_desc->echan = fsl_chan;
> +	fsl_desc->n_tcds = sg_len;
> +	for (i = 0; i < sg_len; i++) {
> +		fsl_desc->tcd[i].vtcd = dma_pool_alloc(fsl_chan->tcd_pool,
> +					GFP_NOWAIT, &fsl_desc->tcd[i].ptcd);
> +		if (!fsl_desc->tcd[i].vtcd)
> +			goto err;
> +	}
> +	return fsl_desc;
> +
> +err:
> +	while (--i >= 0)
> +		dma_pool_free(fsl_chan->tcd_pool, fsl_desc->tcd[i].vtcd,
> +				fsl_desc->tcd[i].ptcd);
> +	kfree(fsl_desc);
> +	return NULL;
> +}
> +
> +static struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
> +		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
> +		size_t period_len, enum dma_transfer_direction direction,
> +		unsigned long flags, void *context)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	struct fsl_edma_desc *fsl_desc;
> +	dma_addr_t dma_buf_next;
> +	int sg_len, i;
> +	u32 src_addr, dst_addr, last_sg, nbytes;
> +	u16 soff, doff, iter;
> +
> +	if (!is_slave_direction(fsl_chan->fsc.dir))
> +		return NULL;
> +
> +	sg_len = buf_len / period_len;
> +	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
> +	if (!fsl_desc)
> +		return NULL;
> +	fsl_desc->iscyclic = true;
> +
> +	dma_buf_next = dma_addr;
> +	nbytes = fsl_chan->fsc.addr_width * fsl_chan->fsc.burst;
> +	iter = period_len / nbytes;
> +
> +	for (i = 0; i < sg_len; i++) {
> +		if (dma_buf_next >= dma_addr + buf_len)
> +			dma_buf_next = dma_addr;
> +
> +		/* get next sg's physical address */
> +		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;
> +
> +		if (fsl_chan->fsc.dir == DMA_MEM_TO_DEV) {
> +			src_addr = dma_buf_next;
> +			dst_addr = fsl_chan->fsc.dev_addr;
> +			soff = fsl_chan->fsc.addr_width;
> +			doff = 0;
> +		} else {
> +			src_addr = fsl_chan->fsc.dev_addr;
> +			dst_addr = dma_buf_next;
> +			soff = 0;
> +			doff = fsl_chan->fsc.addr_width;
> +		}
> +
> +		fill_tcd_params(fsl_chan->edma, fsl_desc->tcd[i].vtcd, src_addr,
> +				dst_addr, fsl_chan->fsc.attr, soff, nbytes, 0,
> +				iter, iter, doff, last_sg, true, false, true);
> +		dma_buf_next += period_len;
> +	}
> +
> +	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
> +}
> +
> +static struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
> +		struct dma_chan *chan, struct scatterlist *sgl,
> +		unsigned int sg_len, enum dma_transfer_direction direction,
> +		unsigned long flags, void *context)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	struct fsl_edma_desc *fsl_desc;
> +	struct scatterlist *sg;
> +	u32 src_addr, dst_addr, last_sg, nbytes;
> +	u16 soff, doff, iter;
> +	int i;
> +
> +	if (!is_slave_direction(fsl_chan->fsc.dir))
> +		return NULL;
> +
> +	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
> +	if (!fsl_desc)
> +		return NULL;
> +	fsl_desc->iscyclic = false;
> +
> +	nbytes = fsl_chan->fsc.addr_width * fsl_chan->fsc.burst;
> +	for_each_sg(sgl, sg, sg_len, i) {
> +		/* get next sg's physical address */
> +		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;
> +
> +		if (fsl_chan->fsc.dir == DMA_MEM_TO_DEV) {
> +			src_addr = sg_dma_address(sg);
> +			dst_addr = fsl_chan->fsc.dev_addr;
> +			soff = fsl_chan->fsc.addr_width;
> +			doff = 0;
> +		} else {
> +			src_addr = fsl_chan->fsc.dev_addr;
> +			dst_addr = sg_dma_address(sg);
> +			soff = 0;
> +			doff = fsl_chan->fsc.addr_width;
> +		}
> +
> +		iter = sg_dma_len(sg) / nbytes;
> +		if (i < sg_len - 1) {
> +			last_sg = fsl_desc->tcd[(i + 1)].ptcd;
> +			fill_tcd_params(fsl_chan->edma, fsl_desc->tcd[i].vtcd,
> +					src_addr, dst_addr, fsl_chan->fsc.attr,
> +					soff, nbytes, 0, iter, iter, doff, last_sg,
> +					false, false, true);
> +		} else {
> +			last_sg = 0;
> +			fill_tcd_params(fsl_chan->edma, fsl_desc->tcd[i].vtcd,
> +					src_addr, dst_addr, fsl_chan->fsc.attr,
> +					soff, nbytes, 0, iter, iter, doff, last_sg,
> +					true, true, false);
> +		}
> +	}
> +
> +	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
> +}
> +
> +static void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
> +{
> +	struct fsl_edma_hw_tcd *tcd;
> +	struct virt_dma_desc *vdesc;
> +
> +	vdesc = vchan_next_desc(&fsl_chan->vchan);
> +	if (!vdesc)
> +		return;
> +	fsl_chan->edesc = to_fsl_edma_desc(vdesc);
> +	tcd = fsl_chan->edesc->tcd[0].vtcd;
> +	fsl_edma_set_tcd_params(fsl_chan, tcd->saddr, tcd->daddr, tcd->attr,
> +			tcd->soff, tcd->nbytes, tcd->slast, tcd->citer,
> +			tcd->biter, tcd->doff, tcd->dlast_sga, tcd->csr);
> +	fsl_edma_enable_request(fsl_chan);
> +	fsl_chan->status = DMA_IN_PROGRESS;
> +}
> +
> +static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
> +{
> +	struct fsl_edma_engine *fsl_edma = dev_id;
> +	unsigned int intr, ch;
> +	void __iomem *base_addr;
> +	struct fsl_edma_chan *fsl_chan;
> +
> +	base_addr = fsl_edma->membase;
> +
> +	intr = edma_readl(fsl_edma, base_addr + EDMA_INTR);
> +	if (!intr)
> +		return IRQ_NONE;
> +
> +	for (ch = 0; ch < fsl_edma->n_chans; ch++) {
> +		if (intr & (0x1 << ch)) {
> +			edma_writeb(fsl_edma, EDMA_CINT_CINT(ch),
> +				base_addr + EDMA_CINT);
> +
> +			fsl_chan = &fsl_edma->chans[ch];
> +
> +			spin_lock(&fsl_chan->vchan.lock);
> +			if (!fsl_chan->edesc->iscyclic) {
> +				list_del(&fsl_chan->edesc->vdesc.node);
> +				vchan_cookie_complete(&fsl_chan->edesc->vdesc);
> +				fsl_chan->edesc = NULL;
> +				fsl_chan->status = DMA_COMPLETE;
> +			} else {
> +				vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
> +			}
> +
> +			if (!fsl_chan->edesc)
> +				fsl_edma_xfer_desc(fsl_chan);
> +
> +			spin_unlock(&fsl_chan->vchan.lock);
> +		}
> +	}
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
> +{
> +	struct fsl_edma_engine *fsl_edma = dev_id;
> +	unsigned int err, ch;
> +
> +	err = edma_readl(fsl_edma, fsl_edma->membase + EDMA_ERR);
> +	if (!err)
> +		return IRQ_NONE;
> +
> +	for (ch = 0; ch < fsl_edma->n_chans; ch++) {
> +		if (err & (0x1 << ch)) {
> +			fsl_edma_disable_request(&fsl_edma->chans[ch]);
> +			edma_writeb(fsl_edma, EDMA_CERR_CERR(ch),
> +				fsl_edma->membase + EDMA_CERR);
> +			fsl_edma->chans[ch].status = DMA_ERROR;
> +		}
> +	}
> +	return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
> +{
> +	if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
> +		return IRQ_HANDLED;
> +
> +	return fsl_edma_err_handler(irq, dev_id);
> +}
> +
> +static void fsl_edma_issue_pending(struct dma_chan *chan)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +
> +	if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
> +		fsl_edma_xfer_desc(fsl_chan);
> +
> +	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +}
> +
> +static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
> +		struct of_dma *ofdma)
> +{
> +	struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
> +	struct dma_chan *chan;
> +
> +	if (dma_spec->args_count != 2)
> +		return NULL;
> +
> +	mutex_lock(&fsl_edma->fsl_edma_mutex);
> +	list_for_each_entry(chan, &fsl_edma->dma_dev.channels, device_node) {
> +		if (chan->client_count)
> +			continue;
> +		if ((chan->chan_id / DMAMUX_NR) == dma_spec->args[0]) {
> +			chan = dma_get_slave_channel(chan);
> +			if (chan) {
> +				chan->device->privatecnt++;
> +				fsl_edma_chan_mux(to_fsl_edma_chan(chan),
> +					dma_spec->args[1], true);
> +				mutex_unlock(&fsl_edma->fsl_edma_mutex);
> +				return chan;
> +			}
> +		}
> +	}
> +	mutex_unlock(&fsl_edma->fsl_edma_mutex);
> +	return NULL;
> +}
> +
> +static int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +
> +	fsl_chan->tcd_pool = dma_pool_create("tcd_pool", chan->device->dev,
> +				sizeof(struct fsl_edma_hw_tcd),
> +				32, 0);
> +	return 0;
> +}
> +
> +static void fsl_edma_free_chan_resources(struct dma_chan *chan)
> +{
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	unsigned long flags;
> +	LIST_HEAD(head);
> +
> +	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
> +	fsl_edma_disable_request(fsl_chan);
> +	fsl_edma_chan_mux(fsl_chan, 0, false);
> +	fsl_chan->edesc = NULL;
> +	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
> +	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
> +
> +	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
> +	dma_pool_destroy(fsl_chan->tcd_pool);
> +	fsl_chan->tcd_pool = NULL;
> +}
> +
> +static int fsl_dma_device_slave_caps(struct dma_chan *dchan,
> +		struct dma_slave_caps *caps)
> +{
> +	caps->src_addr_widths = FSL_EDMA_BUSWIDTHS;
> +	caps->dstn_addr_widths = FSL_EDMA_BUSWIDTHS;
> +	caps->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
> +	caps->cmd_pause = true;
> +	caps->cmd_terminate = true;
> +
> +	return 0;
> +}
> +
> +static int
> +fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
> +{
> +	int ret;
> +
> +	fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
> +	if (fsl_edma->txirq < 0) {
> +		dev_err(&pdev->dev, "Can't get edma-tx irq.\n");
> +		return fsl_edma->txirq;
> +	}
> +
> +	fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
> +	if (fsl_edma->errirq < 0) {
> +		dev_err(&pdev->dev, "Can't get edma-err irq.\n");
> +		return fsl_edma->errirq;
> +	}
> +
> +	if (fsl_edma->txirq == fsl_edma->errirq) {
> +		ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
> +				fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Can't register eDMA IRQ.\n");
> +			 return  ret;
> +		}
> +	} else {
> +		ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
> +				fsl_edma_tx_handler, 0, "eDMA tx", fsl_edma);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
> +			return  ret;
> +		}
> +
> +		ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
> +				fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
> +			return  ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int fsl_edma_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct fsl_edma_engine *fsl_edma;
> +	struct fsl_edma_chan *fsl_chan;
> +	struct resource *res;
> +	int len, chans;
> +	int ret, i;
> +
> +	ret = of_property_read_u32(np, "dma-channels", &chans);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Can't get dma-channels.\n");
> +		return ret;
> +	}
> +
> +	len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
> +	fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
> +	if (!fsl_edma)
> +		return -ENOMEM;
> +
> +	fsl_edma->n_chans = chans;
> +	mutex_init(&fsl_edma->fsl_edma_mutex);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	fsl_edma->membase = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(fsl_edma->membase))
> +		return PTR_ERR(fsl_edma->membase);
> +
> +	for (i = 0; i < DMAMUX_NR; i++) {
> +		char clkname[32];
> +
> +		res = platform_get_resource(pdev, IORESOURCE_MEM, 1 + i);
> +		fsl_edma->muxbase[i] = devm_ioremap_resource(&pdev->dev, res);
> +		if (IS_ERR(fsl_edma->muxbase[i]))
> +			return PTR_ERR(fsl_edma->muxbase[i]);
> +
> +		sprintf(clkname, "dmamux%d", i);
> +		fsl_edma->muxclk[i] = devm_clk_get(&pdev->dev, clkname);
> +		if (IS_ERR(fsl_edma->muxclk[i])) {
> +			dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
> +			return PTR_ERR(fsl_edma->muxclk[i]);
> +		}
> +
> +		ret = clk_prepare_enable(fsl_edma->muxclk[i]);
> +		if (ret) {
> +			dev_err(&pdev->dev, "DMAMUX clk block failed.\n");
> +			return ret;
> +		}
> +
> +	}
> +
> +	ret = fsl_edma_irq_init(pdev, fsl_edma);
> +	if (ret)
> +		return ret;
> +
> +	fsl_edma->big_endian = of_property_read_bool(np, "big-endian");
> +
> +	INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
> +	for (i = 0; i < fsl_edma->n_chans; i++) {
> +		struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
> +
> +		fsl_chan->edma = fsl_edma;
> +
> +		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
> +		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
> +
> +		edma_writew(fsl_edma, 0x0, fsl_edma->membase + EDMA_TCD_CSR(i));
> +		fsl_edma_chan_mux(fsl_chan, 0, false);
> +	}
> +
> +	dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
> +	dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
> +	dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
> +
> +	fsl_edma->dma_dev.dev = &pdev->dev;
> +	fsl_edma->dma_dev.device_alloc_chan_resources
> +		= fsl_edma_alloc_chan_resources;
> +	fsl_edma->dma_dev.device_free_chan_resources
> +		= fsl_edma_free_chan_resources;
> +	fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
> +	fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
> +	fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
> +	fsl_edma->dma_dev.device_control = fsl_edma_control;
> +	fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;
> +	fsl_edma->dma_dev.device_slave_caps = fsl_dma_device_slave_caps;
> +
> +	platform_set_drvdata(pdev, fsl_edma);
> +
> +	ret = dma_async_device_register(&fsl_edma->dma_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Can't register Freescale eDMA engine.\n");
> +		return ret;
> +	}
> +
> +	ret = of_dma_controller_register(np, fsl_edma_xlate, fsl_edma);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Can't register Freescale eDMA of_dma.\n");
> +		dma_async_device_unregister(&fsl_edma->dma_dev);
> +		return ret;
> +	}
> +
> +	/* enable round robin arbitration */
> +	edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, fsl_edma->membase + EDMA_CR);
> +
> +	return 0;
> +}
> +
> +static int fsl_edma_remove(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
> +	int i;
> +
> +	of_dma_controller_free(np);
> +	dma_async_device_unregister(&fsl_edma->dma_dev);
> +
> +	for (i = 0; i < DMAMUX_NR; i++)
> +		clk_disable_unprepare(fsl_edma->muxclk[i]);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id fsl_edma_dt_ids[] = {
> +	{ .compatible = "fsl,vf610-edma", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
> +
> +static struct platform_driver fsl_edma_driver = {
> +	.driver		= {
> +		.name	= "fsl-edma",
> +		.owner  = THIS_MODULE,
> +		.of_match_table = fsl_edma_dt_ids,
> +	},
> +	.probe          = fsl_edma_probe,
> +	.remove		= fsl_edma_remove,
> +};
> +
> +module_platform_driver(fsl_edma_driver);
> +
> +MODULE_ALIAS("platform:fsl-edma");
> +MODULE_DESCRIPTION("Freescale eDMA engine driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.8.0
> 
> 

--