ARM: davinci: move private EDMA API to arm/common

Move mach-davinci/dma.c to common/edma.c so it can be used
by OMAP (specifically AM33xx) as well.

Signed-off-by: Matt Porter <mporter@ti.com>
Acked-by: Chris Ball <cjb@laptop.org> # davinci_mmc.c
Acked-by: Mark Brown <broonie@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
[nsekhar@ti.com: dropped davinci sffsdr changes]
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

3 files changed, 1595 insertions, 0 deletions

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 9353184d730d..c3a4e9ceba34 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -17,3 +17,6 @@ config SHARP_PARAM
 
 config SHARP_SCOOP
 	bool
+
+config TI_PRIV_EDMA
+	bool
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 48434cbe3e89..8c60f473e976 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_ARM_TIMER_SP804)	+= timer-sp.o
 obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
 AFLAGS_mcpm_head.o		:= -march=armv7-a
 AFLAGS_vlock.o			:= -march=armv7-a
+obj-$(CONFIG_TI_PRIV_EDMA)	+= edma.o
diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
new file mode 100644
index 000000000000..dcaeb8ec5d38
--- /dev/null
+++ b/arch/arm/common/edma.c
@@ -0,0 +1,1591 @@
+/*
+ * EDMA3 support for DaVinci
+ *
+ * Copyright (C) 2006-2009 Texas Instruments.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <linux/platform_data/edma.h>
+
+/* Offsets matching "struct edmacc_param" */
+#define PARM_OPT		0x00
+#define PARM_SRC		0x04
+#define PARM_A_B_CNT		0x08
+#define PARM_DST		0x0c
+#define PARM_SRC_DST_BIDX	0x10
+#define PARM_LINK_BCNTRLD	0x14
+#define PARM_SRC_DST_CIDX	0x18
+#define PARM_CCNT		0x1c
+
+#define PARM_SIZE		0x20
+
+/* Offsets for EDMA CC global channel registers and their shadows */
+#define SH_ER		0x00	/* 64 bits */
+#define SH_ECR		0x08	/* 64 bits */
+#define SH_ESR		0x10	/* 64 bits */
+#define SH_CER		0x18	/* 64 bits */
+#define SH_EER		0x20	/* 64 bits */
+#define SH_EECR		0x28	/* 64 bits */
+#define SH_EESR		0x30	/* 64 bits */
+#define SH_SER		0x38	/* 64 bits */
+#define SH_SECR		0x40	/* 64 bits */
+#define SH_IER		0x50	/* 64 bits */
+#define SH_IECR		0x58	/* 64 bits */
+#define SH_IESR		0x60	/* 64 bits */
+#define SH_IPR		0x68	/* 64 bits */
+#define SH_ICR		0x70	/* 64 bits */
+#define SH_IEVAL	0x78
+#define SH_QER		0x80
+#define SH_QEER		0x84
+#define SH_QEECR	0x88
+#define SH_QEESR	0x8c
+#define SH_QSER		0x90
+#define SH_QSECR	0x94
+#define SH_SIZE		0x200
+
+/* Offsets for EDMA CC global registers */
+#define EDMA_REV	0x0000
+#define EDMA_CCCFG	0x0004
+#define EDMA_QCHMAP	0x0200	/* 8 registers */
+#define EDMA_DMAQNUM	0x0240	/* 8 registers (4 on OMAP-L1xx) */
+#define EDMA_QDMAQNUM	0x0260
+#define EDMA_QUETCMAP	0x0280
+#define EDMA_QUEPRI	0x0284
+#define EDMA_EMR	0x0300	/* 64 bits */
+#define EDMA_EMCR	0x0308	/* 64 bits */
+#define EDMA_QEMR	0x0310
+#define EDMA_QEMCR	0x0314
+#define EDMA_CCERR	0x0318
+#define EDMA_CCERRCLR	0x031c
+#define EDMA_EEVAL	0x0320
+#define EDMA_DRAE	0x0340	/* 4 x 64 bits*/
+#define EDMA_QRAE	0x0380	/* 4 registers */
+#define EDMA_QUEEVTENTRY	0x0400	/* 2 x 16 registers */
+#define EDMA_QSTAT	0x0600	/* 2 registers */
+#define EDMA_QWMTHRA	0x0620
+#define EDMA_QWMTHRB	0x0624
+#define EDMA_CCSTAT	0x0640
+
+#define EDMA_M		0x1000	/* global channel registers */
+#define EDMA_ECR	0x1008
+#define EDMA_ECRH	0x100C
+#define EDMA_SHADOW0	0x2000	/* 4 regions shadowing global channels */
+#define EDMA_PARM	0x4000	/* 128 param entries */
+
+#define PARM_OFFSET(param_no)	(EDMA_PARM + ((param_no) << 5))
+
+#define EDMA_DCHMAP	0x0100  /* 64 registers */
+#define CHMAP_EXIST	BIT(24)
+
+#define EDMA_MAX_DMACH           64
+#define EDMA_MAX_PARAMENTRY     512
+
+/*****************************************************************************/
+
+static void __iomem *edmacc_regs_base[EDMA_MAX_CC];
+
+static inline unsigned int edma_read(unsigned ctlr, int offset)
+{
+	return (unsigned int)__raw_readl(edmacc_regs_base[ctlr] + offset);
+}
+
+static inline void edma_write(unsigned ctlr, int offset, int val)
+{
+	__raw_writel(val, edmacc_regs_base[ctlr] + offset);
+}
+static inline void edma_modify(unsigned ctlr, int offset, unsigned and,
+		unsigned or)
+{
+	unsigned val = edma_read(ctlr, offset);
+	val &= and;
+	val |= or;
+	edma_write(ctlr, offset, val);
+}
+static inline void edma_and(unsigned ctlr, int offset, unsigned and)
+{
+	unsigned val = edma_read(ctlr, offset);
+	val &= and;
+	edma_write(ctlr, offset, val);
+}
+static inline void edma_or(unsigned ctlr, int offset, unsigned or)
+{
+	unsigned val = edma_read(ctlr, offset);
+	val |= or;
+	edma_write(ctlr, offset, val);
+}
+static inline unsigned int edma_read_array(unsigned ctlr, int offset, int i)
+{
+	return edma_read(ctlr, offset + (i << 2));
+}
+static inline void edma_write_array(unsigned ctlr, int offset, int i,
+		unsigned val)
+{
+	edma_write(ctlr, offset + (i << 2), val);
+}
+static inline void edma_modify_array(unsigned ctlr, int offset, int i,
+		unsigned and, unsigned or)
+{
+	edma_modify(ctlr, offset + (i << 2), and, or);
+}
+static inline void edma_or_array(unsigned ctlr, int offset, int i, unsigned or)
+{
+	edma_or(ctlr, offset + (i << 2), or);
+}
+static inline void edma_or_array2(unsigned ctlr, int offset, int i, int j,
+		unsigned or)
+{
+	edma_or(ctlr, offset + ((i*2 + j) << 2), or);
+}
+static inline void edma_write_array2(unsigned ctlr, int offset, int i, int j,
+		unsigned val)
+{
+	edma_write(ctlr, offset + ((i*2 + j) << 2), val);
+}
+static inline unsigned int edma_shadow0_read(unsigned ctlr, int offset)
+{
+	return edma_read(ctlr, EDMA_SHADOW0 + offset);
+}
+static inline unsigned int edma_shadow0_read_array(unsigned ctlr, int offset,
+		int i)
+{
+	return edma_read(ctlr, EDMA_SHADOW0 + offset + (i << 2));
+}
+static inline void edma_shadow0_write(unsigned ctlr, int offset, unsigned val)
+{
+	edma_write(ctlr, EDMA_SHADOW0 + offset, val);
+}
+static inline void edma_shadow0_write_array(unsigned ctlr, int offset, int i,
+		unsigned val)
+{
+	edma_write(ctlr, EDMA_SHADOW0 + offset + (i << 2), val);
+}
+static inline unsigned int edma_parm_read(unsigned ctlr, int offset,
+		int param_no)
+{
+	return edma_read(ctlr, EDMA_PARM + offset + (param_no << 5));
+}
+static inline void edma_parm_write(unsigned ctlr, int offset, int param_no,
+		unsigned val)
+{
+	edma_write(ctlr, EDMA_PARM + offset + (param_no << 5), val);
+}
+static inline void edma_parm_modify(unsigned ctlr, int offset, int param_no,
+		unsigned and, unsigned or)
+{
+	edma_modify(ctlr, EDMA_PARM + offset + (param_no << 5), and, or);
+}
+static inline void edma_parm_and(unsigned ctlr, int offset, int param_no,
+		unsigned and)
+{
+	edma_and(ctlr, EDMA_PARM + offset + (param_no << 5), and);
+}
+static inline void edma_parm_or(unsigned ctlr, int offset, int param_no,
+		unsigned or)
+{
+	edma_or(ctlr, EDMA_PARM + offset + (param_no << 5), or);
+}
+
+static inline void set_bits(int offset, int len, unsigned long *p)
+{
+	for (; len > 0; len--)
+		set_bit(offset + (len - 1), p);
+}
+
+static inline void clear_bits(int offset, int len, unsigned long *p)
+{
+	for (; len > 0; len--)
+		clear_bit(offset + (len - 1), p);
+}
+
+/*****************************************************************************/
+
+/* actual number of DMA channels and slots on this silicon */
+struct edma {
+	/* how many dma resources of each type */
+	unsigned	num_channels;
+	unsigned	num_region;
+	unsigned	num_slots;
+	unsigned	num_tc;
+	unsigned	num_cc;
+	enum dma_event_q 	default_queue;
+
+	/* list of channels with no even trigger; terminated by "-1" */
+	const s8	*noevent;
+
+	/* The edma_inuse bit for each PaRAM slot is clear unless the
+	 * channel is in use ... by ARM or DSP, for QDMA, or whatever.
+	 */
+	DECLARE_BITMAP(edma_inuse, EDMA_MAX_PARAMENTRY);
+
+	/* The edma_unused bit for each channel is clear unless
+	 * it is not being used on this platform. It uses a bit
+	 * of SOC-specific initialization code.
+	 */
+	DECLARE_BITMAP(edma_unused, EDMA_MAX_DMACH);
+
+	unsigned	irq_res_start;
+	unsigned	irq_res_end;
+
+	struct dma_interrupt_data {
+		void (*callback)(unsigned channel, unsigned short ch_status,
+				void *data);
+		void *data;
+	} intr_data[EDMA_MAX_DMACH];
+};
+
+static struct edma *edma_cc[EDMA_MAX_CC];
+static int arch_num_cc;
+
+/* dummy param set used to (re)initialize parameter RAM slots */
+static const struct edmacc_param dummy_paramset = {
+	.link_bcntrld = 0xffff,
+	.ccnt = 1,
+};
+
+/*****************************************************************************/
+
+static void map_dmach_queue(unsigned ctlr, unsigned ch_no,
+		enum dma_event_q queue_no)
+{
+	int bit = (ch_no & 0x7) * 4;
+
+	/* default to low priority queue */
+	if (queue_no == EVENTQ_DEFAULT)
+		queue_no = edma_cc[ctlr]->default_queue;
+
+	queue_no &= 7;
+	edma_modify_array(ctlr, EDMA_DMAQNUM, (ch_no >> 3),
+			~(0x7 << bit), queue_no << bit);
+}
+
+static void __init map_queue_tc(unsigned ctlr, int queue_no, int tc_no)
+{
+	int bit = queue_no * 4;
+	edma_modify(ctlr, EDMA_QUETCMAP, ~(0x7 << bit), ((tc_no & 0x7) << bit));
+}
+
+static void __init assign_priority_to_queue(unsigned ctlr, int queue_no,
+		int priority)
+{
+	int bit = queue_no * 4;
+	edma_modify(ctlr, EDMA_QUEPRI, ~(0x7 << bit),
+			((priority & 0x7) << bit));
+}
+
+/**
+ * map_dmach_param - Maps channel number to param entry number
+ *
+ * This maps the dma channel number to param entry numberter. In
+ * other words using the DMA channel mapping registers a param entry
+ * can be mapped to any channel
+ *
+ * Callers are responsible for ensuring the channel mapping logic is
+ * included in that particular EDMA variant (Eg : dm646x)
+ *
+ */
+static void __init map_dmach_param(unsigned ctlr)
+{
+	int i;
+	for (i = 0; i < EDMA_MAX_DMACH; i++)
+		edma_write_array(ctlr, EDMA_DCHMAP , i , (i << 5));
+}
+
+static inline void
+setup_dma_interrupt(unsigned lch,
+	void (*callback)(unsigned channel, u16 ch_status, void *data),
+	void *data)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(lch);
+	lch = EDMA_CHAN_SLOT(lch);
+
+	if (!callback)
+		edma_shadow0_write_array(ctlr, SH_IECR, lch >> 5,
+				BIT(lch & 0x1f));
+
+	edma_cc[ctlr]->intr_data[lch].callback = callback;
+	edma_cc[ctlr]->intr_data[lch].data = data;
+
+	if (callback) {
+		edma_shadow0_write_array(ctlr, SH_ICR, lch >> 5,
+				BIT(lch & 0x1f));
+		edma_shadow0_write_array(ctlr, SH_IESR, lch >> 5,
+				BIT(lch & 0x1f));
+	}
+}
+
+static int irq2ctlr(int irq)
+{
+	if (irq >= edma_cc[0]->irq_res_start && irq <= edma_cc[0]->irq_res_end)
+		return 0;
+	else if (irq >= edma_cc[1]->irq_res_start &&
+		irq <= edma_cc[1]->irq_res_end)
+		return 1;
+
+	return -1;
+}
+
+/******************************************************************************
+ *
+ * DMA interrupt handler
+ *
+ *****************************************************************************/
+static irqreturn_t dma_irq_handler(int irq, void *data)
+{
+	int ctlr;
+	u32 sh_ier;
+	u32 sh_ipr;
+	u32 bank;
+
+	ctlr = irq2ctlr(irq);
+	if (ctlr < 0)
+		return IRQ_NONE;
+
+	dev_dbg(data, "dma_irq_handler\n");
+
+	sh_ipr = edma_shadow0_read_array(ctlr, SH_IPR, 0);
+	if (!sh_ipr) {
+		sh_ipr = edma_shadow0_read_array(ctlr, SH_IPR, 1);
+		if (!sh_ipr)
+			return IRQ_NONE;
+		sh_ier = edma_shadow0_read_array(ctlr, SH_IER, 1);
+		bank = 1;
+	} else {
+		sh_ier = edma_shadow0_read_array(ctlr, SH_IER, 0);
+		bank = 0;
+	}
+
+	do {
+		u32 slot;
+		u32 channel;
+
+		dev_dbg(data, "IPR%d %08x\n", bank, sh_ipr);
+
+		slot = __ffs(sh_ipr);
+		sh_ipr &= ~(BIT(slot));
+
+		if (sh_ier & BIT(slot)) {
+			channel = (bank << 5) | slot;
+			/* Clear the corresponding IPR bits */
+			edma_shadow0_write_array(ctlr, SH_ICR, bank,
+					BIT(slot));
+			if (edma_cc[ctlr]->intr_data[channel].callback)
+				edma_cc[ctlr]->intr_data[channel].callback(
+					channel, DMA_COMPLETE,
+					edma_cc[ctlr]->intr_data[channel].data);
+		}
+	} while (sh_ipr);
+
+	edma_shadow0_write(ctlr, SH_IEVAL, 1);
+	return IRQ_HANDLED;
+}
+
+/******************************************************************************
+ *
+ * DMA error interrupt handler
+ *
+ *****************************************************************************/
+static irqreturn_t dma_ccerr_handler(int irq, void *data)
+{
+	int i;
+	int ctlr;
+	unsigned int cnt = 0;
+
+	ctlr = irq2ctlr(irq);
+	if (ctlr < 0)
+		return IRQ_NONE;
+
+	dev_dbg(data, "dma_ccerr_handler\n");
+
+	if ((edma_read_array(ctlr, EDMA_EMR, 0) == 0) &&
+	    (edma_read_array(ctlr, EDMA_EMR, 1) == 0) &&
+	    (edma_read(ctlr, EDMA_QEMR) == 0) &&
+	    (edma_read(ctlr, EDMA_CCERR) == 0))
+		return IRQ_NONE;
+
+	while (1) {
+		int j = -1;
+		if (edma_read_array(ctlr, EDMA_EMR, 0))
+			j = 0;
+		else if (edma_read_array(ctlr, EDMA_EMR, 1))
+			j = 1;
+		if (j >= 0) {
+			dev_dbg(data, "EMR%d %08x\n", j,
+					edma_read_array(ctlr, EDMA_EMR, j));
+			for (i = 0; i < 32; i++) {
+				int k = (j << 5) + i;
+				if (edma_read_array(ctlr, EDMA_EMR, j) &
+							BIT(i)) {
+					/* Clear the corresponding EMR bits */
+					edma_write_array(ctlr, EDMA_EMCR, j,
+							BIT(i));
+					/* Clear any SER */
+					edma_shadow0_write_array(ctlr, SH_SECR,
+								j, BIT(i));
+					if (edma_cc[ctlr]->intr_data[k].
+								callback) {
+						edma_cc[ctlr]->intr_data[k].
+						callback(k,
+						DMA_CC_ERROR,
+						edma_cc[ctlr]->intr_data
+						[k].data);
+					}
+				}
+			}
+		} else if (edma_read(ctlr, EDMA_QEMR)) {
+			dev_dbg(data, "QEMR %02x\n",
+				edma_read(ctlr, EDMA_QEMR));
+			for (i = 0; i < 8; i++) {
+				if (edma_read(ctlr, EDMA_QEMR) & BIT(i)) {
+					/* Clear the corresponding IPR bits */
+					edma_write(ctlr, EDMA_QEMCR, BIT(i));
+					edma_shadow0_write(ctlr, SH_QSECR,
+								BIT(i));
+
+					/* NOTE:  not reported!! */
+				}
+			}
+		} else if (edma_read(ctlr, EDMA_CCERR)) {
+			dev_dbg(data, "CCERR %08x\n",
+				edma_read(ctlr, EDMA_CCERR));
+			/* FIXME:  CCERR.BIT(16) ignored!  much better
+			 * to just write CCERRCLR with CCERR value...
+			 */
+			for (i = 0; i < 8; i++) {
+				if (edma_read(ctlr, EDMA_CCERR) & BIT(i)) {
+					/* Clear the corresponding IPR bits */
+					edma_write(ctlr, EDMA_CCERRCLR, BIT(i));
+
+					/* NOTE:  not reported!! */
+				}
+			}
+		}
+		if ((edma_read_array(ctlr, EDMA_EMR, 0) == 0) &&
+		    (edma_read_array(ctlr, EDMA_EMR, 1) == 0) &&
+		    (edma_read(ctlr, EDMA_QEMR) == 0) &&
+		    (edma_read(ctlr, EDMA_CCERR) == 0))
+			break;
+		cnt++;
+		if (cnt > 10)
+			break;
+	}
+	edma_write(ctlr, EDMA_EEVAL, 1);
+	return IRQ_HANDLED;
+}
+
+/******************************************************************************
+ *
+ * Transfer controller error interrupt handlers
+ *
+ *****************************************************************************/
+
+#define tc_errs_handled	false	/* disabled as long as they're NOPs */
+
+static irqreturn_t dma_tc0err_handler(int irq, void *data)
+{
+	dev_dbg(data, "dma_tc0err_handler\n");
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t dma_tc1err_handler(int irq, void *data)
+{
+	dev_dbg(data, "dma_tc1err_handler\n");
+	return IRQ_HANDLED;
+}
+
+static int reserve_contiguous_slots(int ctlr, unsigned int id,
+				     unsigned int num_slots,
+				     unsigned int start_slot)
+{
+	int i, j;
+	unsigned int count = num_slots;
+	int stop_slot = start_slot;
+	DECLARE_BITMAP(tmp_inuse, EDMA_MAX_PARAMENTRY);
+
+	for (i = start_slot; i < edma_cc[ctlr]->num_slots; ++i) {
+		j = EDMA_CHAN_SLOT(i);
+		if (!test_and_set_bit(j, edma_cc[ctlr]->edma_inuse)) {
+			/* Record our current beginning slot */
+			if (count == num_slots)
+				stop_slot = i;
+
+			count--;
+			set_bit(j, tmp_inuse);
+
+			if (count == 0)
+				break;
+		} else {
+			clear_bit(j, tmp_inuse);
+
+			if (id == EDMA_CONT_PARAMS_FIXED_EXACT) {
+				stop_slot = i;
+				break;
+			} else {
+				count = num_slots;
+			}
+		}
+	}
+
+	/*
+	 * We have to clear any bits that we set
+	 * if we run out parameter RAM slots, i.e we do find a set
+	 * of contiguous parameter RAM slots but do not find the exact number
+	 * requested as we may reach the total number of parameter RAM slots
+	 */
+	if (i == edma_cc[ctlr]->num_slots)
+		stop_slot = i;
+
+	j = start_slot;
+	for_each_set_bit_from(j, tmp_inuse, stop_slot)
+		clear_bit(j, edma_cc[ctlr]->edma_inuse);
+
+	if (count)
+		return -EBUSY;
+
+	for (j = i - num_slots + 1; j <= i; ++j)
+		memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(j),
+			&dummy_paramset, PARM_SIZE);
+
+	return EDMA_CTLR_CHAN(ctlr, i - num_slots + 1);
+}
+
+static int prepare_unused_channel_list(struct device *dev, void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	int i, ctlr;
+
+	for (i = 0; i < pdev->num_resources; i++) {
+		if ((pdev->resource[i].flags & IORESOURCE_DMA) &&
+				(int)pdev->resource[i].start >= 0) {
+			ctlr = EDMA_CTLR(pdev->resource[i].start);
+			clear_bit(EDMA_CHAN_SLOT(pdev->resource[i].start),
+					edma_cc[ctlr]->edma_unused);
+		}
+	}
+
+	return 0;
+}
+
+/*-----------------------------------------------------------------------*/
+
+static bool unused_chan_list_done;
+
+/* Resource alloc/free:  dma channels, parameter RAM slots */
+
+/**
+ * edma_alloc_channel - allocate DMA channel and paired parameter RAM
+ * @channel: specific channel to allocate; negative for "any unmapped channel"
+ * @callback: optional; to be issued on DMA completion or errors
+ * @data: passed to callback
+ * @eventq_no: an EVENTQ_* constant, used to choose which Transfer
+ *	Controller (TC) executes requests using this channel.  Use
+ *	EVENTQ_DEFAULT unless you really need a high priority queue.
+ *
+ * This allocates a DMA channel and its associated parameter RAM slot.
+ * The parameter RAM is initialized to hold a dummy transfer.
+ *
+ * Normal use is to pass a specific channel number as @channel, to make
+ * use of hardware events mapped to that channel.  When the channel will
+ * be used only for software triggering or event chaining, channels not
+ * mapped to hardware events (or mapped to unused events) are preferable.
+ *
+ * DMA transfers start from a channel using edma_start(), or by
+ * chaining.  When the transfer described in that channel's parameter RAM
+ * slot completes, that slot's data may be reloaded through a link.
+ *
+ * DMA errors are only reported to the @callback associated with the
+ * channel driving that transfer, but transfer completion callbacks can
+ * be sent to another channel under control of the TCC field in
+ * the option word of the transfer's parameter RAM set.  Drivers must not
+ * use DMA transfer completion callbacks for channels they did not allocate.
+ * (The same applies to TCC codes used in transfer chaining.)
+ *
+ * Returns the number of the channel, else negative errno.
+ */
+int edma_alloc_channel(int channel,
+		void (*callback)(unsigned channel, u16 ch_status, void *data),
+		void *data,
+		enum dma_event_q eventq_no)
+{
+	unsigned i, done = 0, ctlr = 0;
+	int ret = 0;
+
+	if (!unused_chan_list_done) {
+		/*
+		 * Scan all the platform devices to find out the EDMA channels
+		 * used and clear them in the unused list, making the rest
+		 * available for ARM usage.
+		 */
+		ret = bus_for_each_dev(&platform_bus_type, NULL, NULL,
+				prepare_unused_channel_list);
+		if (ret < 0)
+			return ret;
+
+		unused_chan_list_done = true;
+	}
+
+	if (channel >= 0) {
+		ctlr = EDMA_CTLR(channel);
+		channel = EDMA_CHAN_SLOT(channel);
+	}
+
+	if (channel < 0) {
+		for (i = 0; i < arch_num_cc; i++) {
+			channel = 0;
+			for (;;) {
+				channel = find_next_bit(edma_cc[i]->edma_unused,
+						edma_cc[i]->num_channels,
+						channel);
+				if (channel == edma_cc[i]->num_channels)
+					break;
+				if (!test_and_set_bit(channel,
+						edma_cc[i]->edma_inuse)) {
+					done = 1;
+					ctlr = i;
+					break;
+				}
+				channel++;
+			}
+			if (done)
+				break;
+		}
+		if (!done)
+			return -ENOMEM;
+	} else if (channel >= edma_cc[ctlr]->num_channels) {
+		return -EINVAL;
+	} else if (test_and_set_bit(channel, edma_cc[ctlr]->edma_inuse)) {
+		return -EBUSY;
+	}
+
+	/* ensure access through shadow region 0 */
+	edma_or_array2(ctlr, EDMA_DRAE, 0, channel >> 5, BIT(channel & 0x1f));
+
+	/* ensure no events are pending */
+	edma_stop(EDMA_CTLR_CHAN(ctlr, channel));
+	memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(channel),
+			&dummy_paramset, PARM_SIZE);
+
+	if (callback)
+		setup_dma_interrupt(EDMA_CTLR_CHAN(ctlr, channel),
+					callback, data);
+
+	map_dmach_queue(ctlr, channel, eventq_no);
+
+	return EDMA_CTLR_CHAN(ctlr, channel);
+}
+EXPORT_SYMBOL(edma_alloc_channel);
+
+
+/**
+ * edma_free_channel - deallocate DMA channel
+ * @channel: dma channel returned from edma_alloc_channel()
+ *
+ * This deallocates the DMA channel and associated parameter RAM slot
+ * allocated by edma_alloc_channel().
+ *
+ * Callers are responsible for ensuring the channel is inactive, and
+ * will not be reactivated by linking, chaining, or software calls to
+ * edma_start().
+ */
+void edma_free_channel(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel >= edma_cc[ctlr]->num_channels)
+		return;
+
+	setup_dma_interrupt(channel, NULL, NULL);
+	/* REVISIT should probably take out of shadow region 0 */
+
+	memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(channel),
+			&dummy_paramset, PARM_SIZE);
+	clear_bit(channel, edma_cc[ctlr]->edma_inuse);
+}
+EXPORT_SYMBOL(edma_free_channel);
+
+/**
+ * edma_alloc_slot - allocate DMA parameter RAM
+ * @slot: specific slot to allocate; negative for "any unused slot"
+ *
+ * This allocates a parameter RAM slot, initializing it to hold a
+ * dummy transfer.  Slots allocated using this routine have not been
+ * mapped to a hardware DMA channel, and will normally be used by
+ * linking to them from a slot associated with a DMA channel.
+ *
+ * Normal use is to pass EDMA_SLOT_ANY as the @slot, but specific
+ * slots may be allocated on behalf of DSP firmware.
+ *
+ * Returns the number of the slot, else negative errno.
+ */
+int edma_alloc_slot(unsigned ctlr, int slot)
+{
+	if (!edma_cc[ctlr])
+		return -EINVAL;
+
+	if (slot >= 0)
+		slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < 0) {
+		slot = edma_cc[ctlr]->num_channels;
+		for (;;) {
+			slot = find_next_zero_bit(edma_cc[ctlr]->edma_inuse,
+					edma_cc[ctlr]->num_slots, slot);
+			if (slot == edma_cc[ctlr]->num_slots)
+				return -ENOMEM;
+			if (!test_and_set_bit(slot, edma_cc[ctlr]->edma_inuse))
+				break;
+		}
+	} else if (slot < edma_cc[ctlr]->num_channels ||
+			slot >= edma_cc[ctlr]->num_slots) {
+		return -EINVAL;
+	} else if (test_and_set_bit(slot, edma_cc[ctlr]->edma_inuse)) {
+		return -EBUSY;
+	}
+
+	memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(slot),
+			&dummy_paramset, PARM_SIZE);
+
+	return EDMA_CTLR_CHAN(ctlr, slot);
+}
+EXPORT_SYMBOL(edma_alloc_slot);
+
+/**
+ * edma_free_slot - deallocate DMA parameter RAM
+ * @slot: parameter RAM slot returned from edma_alloc_slot()
+ *
+ * This deallocates the parameter RAM slot allocated by edma_alloc_slot().
+ * Callers are responsible for ensuring the slot is inactive, and will
+ * not be activated.
+ */
+void edma_free_slot(unsigned slot)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_channels ||
+		slot >= edma_cc[ctlr]->num_slots)
+		return;
+
+	memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(slot),
+			&dummy_paramset, PARM_SIZE);
+	clear_bit(slot, edma_cc[ctlr]->edma_inuse);
+}
+EXPORT_SYMBOL(edma_free_slot);
+
+
+/**
+ * edma_alloc_cont_slots- alloc contiguous parameter RAM slots
+ * The API will return the starting point of a set of
+ * contiguous parameter RAM slots that have been requested
+ *
+ * @id: can only be EDMA_CONT_PARAMS_ANY or EDMA_CONT_PARAMS_FIXED_EXACT
+ * or EDMA_CONT_PARAMS_FIXED_NOT_EXACT
+ * @count: number of contiguous Paramter RAM slots
+ * @slot  - the start value of Parameter RAM slot that should be passed if id
+ * is EDMA_CONT_PARAMS_FIXED_EXACT or EDMA_CONT_PARAMS_FIXED_NOT_EXACT
+ *
+ * If id is EDMA_CONT_PARAMS_ANY then the API starts looking for a set of
+ * contiguous Parameter RAM slots from parameter RAM 64 in the case of
+ * DaVinci SOCs and 32 in the case of DA8xx SOCs.
+ *
+ * If id is EDMA_CONT_PARAMS_FIXED_EXACT then the API starts looking for a
+ * set of contiguous parameter RAM slots from the "slot" that is passed as an
+ * argument to the API.
+ *
+ * If id is EDMA_CONT_PARAMS_FIXED_NOT_EXACT then the API initially tries
+ * starts looking for a set of contiguous parameter RAMs from the "slot"
+ * that is passed as an argument to the API. On failure the API will try to
+ * find a set of contiguous Parameter RAM slots from the remaining Parameter
+ * RAM slots
+ */
+int edma_alloc_cont_slots(unsigned ctlr, unsigned int id, int slot, int count)
+{
+	/*
+	 * The start slot requested should be greater than
+	 * the number of channels and lesser than the total number
+	 * of slots
+	 */
+	if ((id != EDMA_CONT_PARAMS_ANY) &&
+		(slot < edma_cc[ctlr]->num_channels ||
+		slot >= edma_cc[ctlr]->num_slots))
+		return -EINVAL;
+
+	/*
+	 * The number of parameter RAM slots requested cannot be less than 1
+	 * and cannot be more than the number of slots minus the number of
+	 * channels
+	 */
+	if (count < 1 || count >
+		(edma_cc[ctlr]->num_slots - edma_cc[ctlr]->num_channels))
+		return -EINVAL;
+
+	switch (id) {
+	case EDMA_CONT_PARAMS_ANY:
+		return reserve_contiguous_slots(ctlr, id, count,
+						 edma_cc[ctlr]->num_channels);
+	case EDMA_CONT_PARAMS_FIXED_EXACT:
+	case EDMA_CONT_PARAMS_FIXED_NOT_EXACT:
+		return reserve_contiguous_slots(ctlr, id, count, slot);
+	default:
+		return -EINVAL;
+	}
+
+}
+EXPORT_SYMBOL(edma_alloc_cont_slots);
+
+/**
+ * edma_free_cont_slots - deallocate DMA parameter RAM slots
+ * @slot: first parameter RAM of a set of parameter RAM slots to be freed
+ * @count: the number of contiguous parameter RAM slots to be freed
+ *
+ * This deallocates the parameter RAM slots allocated by
+ * edma_alloc_cont_slots.
+ * Callers/applications need to keep track of sets of contiguous
+ * parameter RAM slots that have been allocated using the edma_alloc_cont_slots
+ * API.
+ * Callers are responsible for ensuring the slots are inactive, and will
+ * not be activated.
+ */
+int edma_free_cont_slots(unsigned slot, int count)
+{
+	unsigned ctlr, slot_to_free;
+	int i;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_channels ||
+		slot >= edma_cc[ctlr]->num_slots ||
+		count < 1)
+		return -EINVAL;
+
+	for (i = slot; i < slot + count; ++i) {
+		ctlr = EDMA_CTLR(i);
+		slot_to_free = EDMA_CHAN_SLOT(i);
+
+		memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(slot_to_free),
+			&dummy_paramset, PARM_SIZE);
+		clear_bit(slot_to_free, edma_cc[ctlr]->edma_inuse);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(edma_free_cont_slots);
+
+/*-----------------------------------------------------------------------*/
+
+/* Parameter RAM operations (i) -- read/write partial slots */
+
+/**
+ * edma_set_src - set initial DMA source address in parameter RAM slot
+ * @slot: parameter RAM slot being configured
+ * @src_port: physical address of source (memory, controller FIFO, etc)
+ * @addressMode: INCR, except in very rare cases
+ * @fifoWidth: ignored unless @addressMode is FIFO, else specifies the
+ *	width to use when addressing the fifo (e.g. W8BIT, W32BIT)
+ *
+ * Note that the source address is modified during the DMA transfer
+ * according to edma_set_src_index().
+ */
+void edma_set_src(unsigned slot, dma_addr_t src_port,
+				enum address_mode mode, enum fifo_width width)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_slots) {
+		unsigned int i = edma_parm_read(ctlr, PARM_OPT, slot);
+
+		if (mode) {
+			/* set SAM and program FWID */
+			i = (i & ~(EDMA_FWID)) | (SAM | ((width & 0x7) << 8));
+		} else {
+			/* clear SAM */
+			i &= ~SAM;
+		}
+		edma_parm_write(ctlr, PARM_OPT, slot, i);
+
+		/* set the source port address
+		   in source register of param structure */
+		edma_parm_write(ctlr, PARM_SRC, slot, src_port);
+	}
+}
+EXPORT_SYMBOL(edma_set_src);
+
+/**
+ * edma_set_dest - set initial DMA destination address in parameter RAM slot
+ * @slot: parameter RAM slot being configured
+ * @dest_port: physical address of destination (memory, controller FIFO, etc)
+ * @addressMode: INCR, except in very rare cases
+ * @fifoWidth: ignored unless @addressMode is FIFO, else specifies the
+ *	width to use when addressing the fifo (e.g. W8BIT, W32BIT)
+ *
+ * Note that the destination address is modified during the DMA transfer
+ * according to edma_set_dest_index().
+ */
+void edma_set_dest(unsigned slot, dma_addr_t dest_port,
+				 enum address_mode mode, enum fifo_width width)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_slots) {
+		unsigned int i = edma_parm_read(ctlr, PARM_OPT, slot);
+
+		if (mode) {
+			/* set DAM and program FWID */
+			i = (i & ~(EDMA_FWID)) | (DAM | ((width & 0x7) << 8));
+		} else {
+			/* clear DAM */
+			i &= ~DAM;
+		}
+		edma_parm_write(ctlr, PARM_OPT, slot, i);
+		/* set the destination port address
+		   in dest register of param structure */
+		edma_parm_write(ctlr, PARM_DST, slot, dest_port);
+	}
+}
+EXPORT_SYMBOL(edma_set_dest);
+
+/**
+ * edma_get_position - returns the current transfer points
+ * @slot: parameter RAM slot being examined
+ * @src: pointer to source port position
+ * @dst: pointer to destination port position
+ *
+ * Returns current source and destination addresses for a particular
+ * parameter RAM slot.  Its channel should not be active when this is called.
+ */
+void edma_get_position(unsigned slot, dma_addr_t *src, dma_addr_t *dst)
+{
+	struct edmacc_param temp;
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	edma_read_slot(EDMA_CTLR_CHAN(ctlr, slot), &temp);
+	if (src != NULL)
+		*src = temp.src;
+	if (dst != NULL)
+		*dst = temp.dst;
+}
+EXPORT_SYMBOL(edma_get_position);
+
+/**
+ * edma_set_src_index - configure DMA source address indexing
+ * @slot: parameter RAM slot being configured
+ * @src_bidx: byte offset between source arrays in a frame
+ * @src_cidx: byte offset between source frames in a block
+ *
+ * Offsets are specified to support either contiguous or discontiguous
+ * memory transfers, or repeated access to a hardware register, as needed.
+ * When accessing hardware registers, both offsets are normally zero.
+ */
+void edma_set_src_index(unsigned slot, s16 src_bidx, s16 src_cidx)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_slots) {
+		edma_parm_modify(ctlr, PARM_SRC_DST_BIDX, slot,
+				0xffff0000, src_bidx);
+		edma_parm_modify(ctlr, PARM_SRC_DST_CIDX, slot,
+				0xffff0000, src_cidx);
+	}
+}
+EXPORT_SYMBOL(edma_set_src_index);
+
+/**
+ * edma_set_dest_index - configure DMA destination address indexing
+ * @slot: parameter RAM slot being configured
+ * @dest_bidx: byte offset between destination arrays in a frame
+ * @dest_cidx: byte offset between destination frames in a block
+ *
+ * Offsets are specified to support either contiguous or discontiguous
+ * memory transfers, or repeated access to a hardware register, as needed.
+ * When accessing hardware registers, both offsets are normally zero.
+ */
+void edma_set_dest_index(unsigned slot, s16 dest_bidx, s16 dest_cidx)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_slots) {
+		edma_parm_modify(ctlr, PARM_SRC_DST_BIDX, slot,
+				0x0000ffff, dest_bidx << 16);
+		edma_parm_modify(ctlr, PARM_SRC_DST_CIDX, slot,
+				0x0000ffff, dest_cidx << 16);
+	}
+}
+EXPORT_SYMBOL(edma_set_dest_index);
+
+/**
+ * edma_set_transfer_params - configure DMA transfer parameters
+ * @slot: parameter RAM slot being configured
+ * @acnt: how many bytes per array (at least one)
+ * @bcnt: how many arrays per frame (at least one)
+ * @ccnt: how many frames per block (at least one)
+ * @bcnt_rld: used only for A-Synchronized transfers; this specifies
+ *	the value to reload into bcnt when it decrements to zero
+ * @sync_mode: ASYNC or ABSYNC
+ *
+ * See the EDMA3 documentation to understand how to configure and link
+ * transfers using the fields in PaRAM slots.  If you are not doing it
+ * all at once with edma_write_slot(), you will use this routine
+ * plus two calls each for source and destination, setting the initial
+ * address and saying how to index that address.
+ *
+ * An example of an A-Synchronized transfer is a serial link using a
+ * single word shift register.  In that case, @acnt would be equal to
+ * that word size; the serial controller issues a DMA synchronization
+ * event to transfer each word, and memory access by the DMA transfer
+ * controller will be word-at-a-time.
+ *
+ * An example of an AB-Synchronized transfer is a device using a FIFO.
+ * In that case, @acnt equals the FIFO width and @bcnt equals its depth.
+ * The controller with the FIFO issues DMA synchronization events when
+ * the FIFO threshold is reached, and the DMA transfer controller will
+ * transfer one frame to (or from) the FIFO.  It will probably use
+ * efficient burst modes to access memory.
+ */
+void edma_set_transfer_params(unsigned slot,
+		u16 acnt, u16 bcnt, u16 ccnt,
+		u16 bcnt_rld, enum sync_dimension sync_mode)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot < edma_cc[ctlr]->num_slots) {
+		edma_parm_modify(ctlr, PARM_LINK_BCNTRLD, slot,
+				0x0000ffff, bcnt_rld << 16);
+		if (sync_mode == ASYNC)
+			edma_parm_and(ctlr, PARM_OPT, slot, ~SYNCDIM);
+		else
+			edma_parm_or(ctlr, PARM_OPT, slot, SYNCDIM);
+		/* Set the acount, bcount, ccount registers */
+		edma_parm_write(ctlr, PARM_A_B_CNT, slot, (bcnt << 16) | acnt);
+		edma_parm_write(ctlr, PARM_CCNT, slot, ccnt);
+	}
+}
+EXPORT_SYMBOL(edma_set_transfer_params);
+
+/**
+ * edma_link - link one parameter RAM slot to another
+ * @from: parameter RAM slot originating the link
+ * @to: parameter RAM slot which is the link target
+ *
+ * The originating slot should not be part of any active DMA transfer.
+ */
+void edma_link(unsigned from, unsigned to)
+{
+	unsigned ctlr_from, ctlr_to;
+
+	ctlr_from = EDMA_CTLR(from);
+	from = EDMA_CHAN_SLOT(from);
+	ctlr_to = EDMA_CTLR(to);
+	to = EDMA_CHAN_SLOT(to);
+
+	if (from >= edma_cc[ctlr_from]->num_slots)
+		return;
+	if (to >= edma_cc[ctlr_to]->num_slots)
+		return;
+	edma_parm_modify(ctlr_from, PARM_LINK_BCNTRLD, from, 0xffff0000,
+				PARM_OFFSET(to));
+}
+EXPORT_SYMBOL(edma_link);
+
+/**
+ * edma_unlink - cut link from one parameter RAM slot
+ * @from: parameter RAM slot originating the link
+ *
+ * The originating slot should not be part of any active DMA transfer.
+ * Its link is set to 0xffff.
+ */
+void edma_unlink(unsigned from)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(from);
+	from = EDMA_CHAN_SLOT(from);
+
+	if (from >= edma_cc[ctlr]->num_slots)
+		return;
+	edma_parm_or(ctlr, PARM_LINK_BCNTRLD, from, 0xffff);
+}
+EXPORT_SYMBOL(edma_unlink);
+
+/*-----------------------------------------------------------------------*/
+
+/* Parameter RAM operations (ii) -- read/write whole parameter sets */
+
+/**
+ * edma_write_slot - write parameter RAM data for slot
+ * @slot: number of parameter RAM slot being modified
+ * @param: data to be written into parameter RAM slot
+ *
+ * Use this to assign all parameters of a transfer at once.  This
+ * allows more efficient setup of transfers than issuing multiple
+ * calls to set up those parameters in small pieces, and provides
+ * complete control over all transfer options.
+ */
+void edma_write_slot(unsigned slot, const struct edmacc_param *param)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot >= edma_cc[ctlr]->num_slots)
+		return;
+	memcpy_toio(edmacc_regs_base[ctlr] + PARM_OFFSET(slot), param,
+			PARM_SIZE);
+}
+EXPORT_SYMBOL(edma_write_slot);
+
+/**
+ * edma_read_slot - read parameter RAM data from slot
+ * @slot: number of parameter RAM slot being copied
+ * @param: where to store copy of parameter RAM data
+ *
+ * Use this to read data from a parameter RAM slot, perhaps to
+ * save them as a template for later reuse.
+ */
+void edma_read_slot(unsigned slot, struct edmacc_param *param)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(slot);
+	slot = EDMA_CHAN_SLOT(slot);
+
+	if (slot >= edma_cc[ctlr]->num_slots)
+		return;
+	memcpy_fromio(param, edmacc_regs_base[ctlr] + PARM_OFFSET(slot),
+			PARM_SIZE);
+}
+EXPORT_SYMBOL(edma_read_slot);
+
+/*-----------------------------------------------------------------------*/
+
+/* Various EDMA channel control operations */
+
+/**
+ * edma_pause - pause dma on a channel
+ * @channel: on which edma_start() has been called
+ *
+ * This temporarily disables EDMA hardware events on the specified channel,
+ * preventing them from triggering new transfers on its behalf
+ */
+void edma_pause(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel < edma_cc[ctlr]->num_channels) {
+		unsigned int mask = BIT(channel & 0x1f);
+
+		edma_shadow0_write_array(ctlr, SH_EECR, channel >> 5, mask);
+	}
+}
+EXPORT_SYMBOL(edma_pause);
+
+/**
+ * edma_resume - resumes dma on a paused channel
+ * @channel: on which edma_pause() has been called
+ *
+ * This re-enables EDMA hardware events on the specified channel.
+ */
+void edma_resume(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel < edma_cc[ctlr]->num_channels) {
+		unsigned int mask = BIT(channel & 0x1f);
+
+		edma_shadow0_write_array(ctlr, SH_EESR, channel >> 5, mask);
+	}
+}
+EXPORT_SYMBOL(edma_resume);
+
+/**
+ * edma_start - start dma on a channel
+ * @channel: channel being activated
+ *
+ * Channels with event associations will be triggered by their hardware
+ * events, and channels without such associations will be triggered by
+ * software.  (At this writing there is no interface for using software
+ * triggers except with channels that don't support hardware triggers.)
+ *
+ * Returns zero on success, else negative errno.
+ */
+int edma_start(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel < edma_cc[ctlr]->num_channels) {
+		int j = channel >> 5;
+		unsigned int mask = BIT(channel & 0x1f);
+
+		/* EDMA channels without event association */
+		if (test_bit(channel, edma_cc[ctlr]->edma_unused)) {
+			pr_debug("EDMA: ESR%d %08x\n", j,
+				edma_shadow0_read_array(ctlr, SH_ESR, j));
+			edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
+			return 0;
+		}
+
+		/* EDMA channel with event association */
+		pr_debug("EDMA: ER%d %08x\n", j,
+			edma_shadow0_read_array(ctlr, SH_ER, j));
+		/* Clear any pending event or error */
+		edma_write_array(ctlr, EDMA_ECR, j, mask);
+		edma_write_array(ctlr, EDMA_EMCR, j, mask);
+		/* Clear any SER */
+		edma_shadow0_write_array(ctlr, SH_SECR, j, mask);
+		edma_shadow0_write_array(ctlr, SH_EESR, j, mask);
+		pr_debug("EDMA: EER%d %08x\n", j,
+			edma_shadow0_read_array(ctlr, SH_EER, j));
+		return 0;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(edma_start);
+
+/**
+ * edma_stop - stops dma on the channel passed
+ * @channel: channel being deactivated
+ *
+ * When @lch is a channel, any active transfer is paused and
+ * all pending hardware events are cleared.  The current transfer
+ * may not be resumed, and the channel's Parameter RAM should be
+ * reinitialized before being reused.
+ */
+void edma_stop(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel < edma_cc[ctlr]->num_channels) {
+		int j = channel >> 5;
+		unsigned int mask = BIT(channel & 0x1f);
+
+		edma_shadow0_write_array(ctlr, SH_EECR, j, mask);
+		edma_shadow0_write_array(ctlr, SH_ECR, j, mask);
+		edma_shadow0_write_array(ctlr, SH_SECR, j, mask);
+		edma_write_array(ctlr, EDMA_EMCR, j, mask);
+
+		pr_debug("EDMA: EER%d %08x\n", j,
+				edma_shadow0_read_array(ctlr, SH_EER, j));
+
+		/* REVISIT:  consider guarding against inappropriate event
+		 * chaining by overwriting with dummy_paramset.
+		 */
+	}
+}
+EXPORT_SYMBOL(edma_stop);
+
+/******************************************************************************
+ *
+ * It cleans ParamEntry qand bring back EDMA to initial state if media has
+ * been removed before EDMA has finished.It is usedful for removable media.
+ * Arguments:
+ *      ch_no     - channel no
+ *
+ * Return: zero on success, or corresponding error no on failure
+ *
+ * FIXME this should not be needed ... edma_stop() should suffice.
+ *
+ *****************************************************************************/
+
+void edma_clean_channel(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel < edma_cc[ctlr]->num_channels) {
+		int j = (channel >> 5);
+		unsigned int mask = BIT(channel & 0x1f);
+
+		pr_debug("EDMA: EMR%d %08x\n", j,
+				edma_read_array(ctlr, EDMA_EMR, j));
+		edma_shadow0_write_array(ctlr, SH_ECR, j, mask);
+		/* Clear the corresponding EMR bits */
+		edma_write_array(ctlr, EDMA_EMCR, j, mask);
+		/* Clear any SER */
+		edma_shadow0_write_array(ctlr, SH_SECR, j, mask);
+		edma_write(ctlr, EDMA_CCERRCLR, BIT(16) | BIT(1) | BIT(0));
+	}
+}
+EXPORT_SYMBOL(edma_clean_channel);
+
+/*
+ * edma_clear_event - clear an outstanding event on the DMA channel
+ * Arguments:
+ *	channel - channel number
+ */
+void edma_clear_event(unsigned channel)
+{
+	unsigned ctlr;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+
+	if (channel >= edma_cc[ctlr]->num_channels)
+		return;
+	if (channel < 32)
+		edma_write(ctlr, EDMA_ECR, BIT(channel));
+	else
+		edma_write(ctlr, EDMA_ECRH, BIT(channel - 32));
+}
+EXPORT_SYMBOL(edma_clear_event);
+
+/*-----------------------------------------------------------------------*/
+
+static int __init edma_probe(struct platform_device *pdev)
+{
+	struct edma_soc_info	**info = pdev->dev.platform_data;
+	const s8		(*queue_priority_mapping)[2];
+	const s8		(*queue_tc_mapping)[2];
+	int			i, j, off, ln, found = 0;
+	int			status = -1;
+	const s16		(*rsv_chans)[2];
+	const s16		(*rsv_slots)[2];
+	int			irq[EDMA_MAX_CC] = {0, 0};
+	int			err_irq[EDMA_MAX_CC] = {0, 0};
+	struct resource		*r[EDMA_MAX_CC] = {NULL};
+	resource_size_t		len[EDMA_MAX_CC];
+	char			res_name[10];
+	char			irq_name[10];
+
+	if (!info)
+		return -ENODEV;
+
+	for (j = 0; j < EDMA_MAX_CC; j++) {
+		sprintf(res_name, "edma_cc%d", j);
+		r[j] = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						res_name);
+		if (!r[j] || !info[j]) {
+			if (found)
+				break;
+			else
+				return -ENODEV;
+		} else {
+			found = 1;
+		}
+
+		len[j] = resource_size(r[j]);
+
+		r[j] = request_mem_region(r[j]->start, len[j],
+			dev_name(&pdev->dev));
+		if (!r[j]) {
+			status = -EBUSY;
+			goto fail1;
+		}
+
+		edmacc_regs_base[j] = ioremap(r[j]->start, len[j]);
+		if (!edmacc_regs_base[j]) {
+			status = -EBUSY;
+			goto fail1;
+		}
+
+		edma_cc[j] = kzalloc(sizeof(struct edma), GFP_KERNEL);
+		if (!edma_cc[j]) {
+			status = -ENOMEM;
+			goto fail1;
+		}
+
+		edma_cc[j]->num_channels = min_t(unsigned, info[j]->n_channel,
+							EDMA_MAX_DMACH);
+		edma_cc[j]->num_slots = min_t(unsigned, info[j]->n_slot,
+							EDMA_MAX_PARAMENTRY);
+		edma_cc[j]->num_cc = min_t(unsigned, info[j]->n_cc,
+							EDMA_MAX_CC);
+
+		edma_cc[j]->default_queue = info[j]->default_queue;
+
+		dev_dbg(&pdev->dev, "DMA REG BASE ADDR=%p\n",
+			edmacc_regs_base[j]);
+
+		for (i = 0; i < edma_cc[j]->num_slots; i++)
+			memcpy_toio(edmacc_regs_base[j] + PARM_OFFSET(i),
+					&dummy_paramset, PARM_SIZE);
+
+		/* Mark all channels as unused */
+		memset(edma_cc[j]->edma_unused, 0xff,
+			sizeof(edma_cc[j]->edma_unused));
+
+		if (info[j]->rsv) {
+
+			/* Clear the reserved channels in unused list */
+			rsv_chans = info[j]->rsv->rsv_chans;
+			if (rsv_chans) {
+				for (i = 0; rsv_chans[i][0] != -1; i++) {
+					off = rsv_chans[i][0];
+					ln = rsv_chans[i][1];
+					clear_bits(off, ln,
+						edma_cc[j]->edma_unused);
+				}
+			}
+
+			/* Set the reserved slots in inuse list */
+			rsv_slots = info[j]->rsv->rsv_slots;
+			if (rsv_slots) {
+				for (i = 0; rsv_slots[i][0] != -1; i++) {
+					off = rsv_slots[i][0];
+					ln = rsv_slots[i][1];
+					set_bits(off, ln,
+						edma_cc[j]->edma_inuse);
+				}
+			}
+		}
+
+		sprintf(irq_name, "edma%d", j);
+		irq[j] = platform_get_irq_byname(pdev, irq_name);
+		edma_cc[j]->irq_res_start = irq[j];
+		status = request_irq(irq[j], dma_irq_handler, 0, "edma",
+					&pdev->dev);
+		if (status < 0) {
+			dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
+				irq[j], status);
+			goto fail;
+		}
+
+		sprintf(irq_name, "edma%d_err", j);
+		err_irq[j] = platform_get_irq_byname(pdev, irq_name);
+		edma_cc[j]->irq_res_end = err_irq[j];
+		status = request_irq(err_irq[j], dma_ccerr_handler, 0,
+					"edma_error", &pdev->dev);
+		if (status < 0) {
+			dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
+				err_irq[j], status);
+			goto fail;
+		}
+
+		for (i = 0; i < edma_cc[j]->num_channels; i++)
+			map_dmach_queue(j, i, info[j]->default_queue);
+
+		queue_tc_mapping = info[j]->queue_tc_mapping;
+		queue_priority_mapping = info[j]->queue_priority_mapping;
+
+		/* Event queue to TC mapping */
+		for (i = 0; queue_tc_mapping[i][0] != -1; i++)
+			map_queue_tc(j, queue_tc_mapping[i][0],
+					queue_tc_mapping[i][1]);
+
+		/* Event queue priority mapping */
+		for (i = 0; queue_priority_mapping[i][0] != -1; i++)
+			assign_priority_to_queue(j,
+						queue_priority_mapping[i][0],
+						queue_priority_mapping[i][1]);
+
+		/* Map the channel to param entry if channel mapping logic
+		 * exist
+		 */
+		if (edma_read(j, EDMA_CCCFG) & CHMAP_EXIST)
+			map_dmach_param(j);
+
+		for (i = 0; i < info[j]->n_region; i++) {
+			edma_write_array2(j, EDMA_DRAE, i, 0, 0x0);
+			edma_write_array2(j, EDMA_DRAE, i, 1, 0x0);
+			edma_write_array(j, EDMA_QRAE, i, 0x0);
+		}
+		arch_num_cc++;
+	}
+
+	if (tc_errs_handled) {
+		status = request_irq(IRQ_TCERRINT0, dma_tc0err_handler, 0,
+					"edma_tc0", &pdev->dev);
+		if (status < 0) {
+			dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
+				IRQ_TCERRINT0, status);
+			return status;
+		}
+		status = request_irq(IRQ_TCERRINT, dma_tc1err_handler, 0,
+					"edma_tc1", &pdev->dev);
+		if (status < 0) {
+			dev_dbg(&pdev->dev, "request_irq %d --> %d\n",
+				IRQ_TCERRINT, status);
+			return status;
+		}
+	}
+
+	return 0;
+
+fail:
+	for (i = 0; i < EDMA_MAX_CC; i++) {
+		if (err_irq[i])
+			free_irq(err_irq[i], &pdev->dev);
+		if (irq[i])
+			free_irq(irq[i], &pdev->dev);
+	}
+fail1:
+	for (i = 0; i < EDMA_MAX_CC; i++) {
+		if (r[i])
+			release_mem_region(r[i]->start, len[i]);
+		if (edmacc_regs_base[i])
+			iounmap(edmacc_regs_base[i]);
+		kfree(edma_cc[i]);
+	}
+	return status;
+}
+
+
+static struct platform_driver edma_driver = {
+	.driver.name	= "edma",
+};
+
+static int __init edma_init(void)
+{
+	return platform_driver_probe(&edma_driver, edma_probe);
+}
+arch_initcall(edma_init);
+