dma: Add Freescale eDMA engine driver support

Add Freescale enhanced direct memory(eDMA) controller support.
This module can be found on Vybrid and LS-1 SoCs.

Signed-off-by: Alison Wang <b18965@freescale.com>
Signed-off-by: Jingchang Lu <b35083@freescale.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 975 insertions, 0 deletions

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
new file mode 100644
index 000000000000..9025300a1670
--- /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");