davinci: add EDMA driver

Original code for 2.6.10 and 2.6.28 series done by Texas Instruments
and MontaVista, but major updates and rework done by Troy Kisky and
David Brownell.

Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Cc: Troy Kisky <troy.kisky@boundarydevices.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 1135 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/dma.c b/arch/arm/mach-davinci/dma.c
new file mode 100644
index 000000000000..15e9eb158bb7
--- /dev/null
+++ b/arch/arm/mach-davinci/dma.c
@@ -0,0 +1,1135 @@
+/*
+ * 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/sched.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/compiler.h>
+#include <linux/io.h>
+
+#include <mach/cputype.h>
+#include <mach/memory.h>
+#include <mach/hardware.h>
+#include <mach/irqs.h>
+#include <mach/edma.h>
+#include <mach/mux.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 DAVINCI_DMA_3PCC_BASE	0x01C00000
+
+#define PARM_OFFSET(param_no)	(EDMA_PARM + ((param_no) << 5))
+
+#define EDMA_MAX_DMACH           64
+#define EDMA_MAX_PARAMENTRY     512
+#define EDMA_MAX_EVQUE            2	/* FIXME too small */
+
+
+/*****************************************************************************/
+
+static void __iomem *edmacc_regs_base;
+
+static inline unsigned int edma_read(int offset)
+{
+	return (unsigned int)__raw_readl(edmacc_regs_base + offset);
+}
+
+static inline void edma_write(int offset, int val)
+{
+	__raw_writel(val, edmacc_regs_base + offset);
+}
+static inline void edma_modify(int offset, unsigned and, unsigned or)
+{
+	unsigned val = edma_read(offset);
+	val &= and;
+	val |= or;
+	edma_write(offset, val);
+}
+static inline void edma_and(int offset, unsigned and)
+{
+	unsigned val = edma_read(offset);
+	val &= and;
+	edma_write(offset, val);
+}
+static inline void edma_or(int offset, unsigned or)
+{
+	unsigned val = edma_read(offset);
+	val |= or;
+	edma_write(offset, val);
+}
+static inline unsigned int edma_read_array(int offset, int i)
+{
+	return edma_read(offset + (i << 2));
+}
+static inline void edma_write_array(int offset, int i, unsigned val)
+{
+	edma_write(offset + (i << 2), val);
+}
+static inline void edma_modify_array(int offset, int i,
+		unsigned and, unsigned or)
+{
+	edma_modify(offset + (i << 2), and, or);
+}
+static inline void edma_or_array(int offset, int i, unsigned or)
+{
+	edma_or(offset + (i << 2), or);
+}
+static inline void edma_or_array2(int offset, int i, int j, unsigned or)
+{
+	edma_or(offset + ((i*2 + j) << 2), or);
+}
+static inline void edma_write_array2(int offset, int i, int j, unsigned val)
+{
+	edma_write(offset + ((i*2 + j) << 2), val);
+}
+static inline unsigned int edma_shadow0_read(int offset)
+{
+	return edma_read(EDMA_SHADOW0 + offset);
+}
+static inline unsigned int edma_shadow0_read_array(int offset, int i)
+{
+	return edma_read(EDMA_SHADOW0 + offset + (i << 2));
+}
+static inline void edma_shadow0_write(int offset, unsigned val)
+{
+	edma_write(EDMA_SHADOW0 + offset, val);
+}
+static inline void edma_shadow0_write_array(int offset, int i, unsigned val)
+{
+	edma_write(EDMA_SHADOW0 + offset + (i << 2), val);
+}
+static inline unsigned int edma_parm_read(int offset, int param_no)
+{
+	return edma_read(EDMA_PARM + offset + (param_no << 5));
+}
+static inline void edma_parm_write(int offset, int param_no, unsigned val)
+{
+	edma_write(EDMA_PARM + offset + (param_no << 5), val);
+}
+static inline void edma_parm_modify(int offset, int param_no,
+		unsigned and, unsigned or)
+{
+	edma_modify(EDMA_PARM + offset + (param_no << 5), and, or);
+}
+static inline void edma_parm_and(int offset, int param_no, unsigned and)
+{
+	edma_and(EDMA_PARM + offset + (param_no << 5), and);
+}
+static inline void edma_parm_or(int offset, int param_no, unsigned or)
+{
+	edma_or(EDMA_PARM + offset + (param_no << 5), or);
+}
+
+/*****************************************************************************/
+
+/* actual number of DMA channels and slots on this silicon */
+static unsigned num_channels;
+static unsigned num_slots;
+
+static struct dma_interrupt_data {
+	void (*callback)(unsigned channel, unsigned short ch_status,
+			 void *data);
+	void *data;
+} intr_data[EDMA_MAX_DMACH];
+
+/* The edma_inuse bit for each PaRAM slot is clear unless the
+ * channel is in use ... by ARM or DSP, for QDMA, or whatever.
+ */
+static DECLARE_BITMAP(edma_inuse, EDMA_MAX_PARAMENTRY);
+
+/* The edma_noevent bit for each channel is clear unless
+ * it doesn't trigger DMA events on this platform.  It uses a
+ * bit of SOC-specific initialization code.
+ */
+static DECLARE_BITMAP(edma_noevent, EDMA_MAX_DMACH);
+
+/* dummy param set used to (re)initialize parameter RAM slots */
+static const struct edmacc_param dummy_paramset = {
+	.link_bcntrld = 0xffff,
+	.ccnt = 1,
+};
+
+static const int __initconst
+queue_tc_mapping[EDMA_MAX_EVQUE + 1][2] = {
+/* {event queue no, TC no} */
+	{0, 0},
+	{1, 1},
+	{-1, -1}
+};
+
+static const int __initconst
+queue_priority_mapping[EDMA_MAX_EVQUE + 1][2] = {
+	/* {event queue no, Priority} */
+	{0, 3},
+	{1, 7},
+	{-1, -1}
+};
+
+/*****************************************************************************/
+
+static void map_dmach_queue(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 = EVENTQ_1;
+
+	queue_no &= 7;
+	edma_modify_array(EDMA_DMAQNUM, (ch_no >> 3),
+			~(0x7 << bit), queue_no << bit);
+}
+
+static void __init map_queue_tc(int queue_no, int tc_no)
+{
+	int bit = queue_no * 4;
+	edma_modify(EDMA_QUETCMAP, ~(0x7 << bit), ((tc_no & 0x7) << bit));
+}
+
+static void __init assign_priority_to_queue(int queue_no, int priority)
+{
+	int bit = queue_no * 4;
+	edma_modify(EDMA_QUEPRI, ~(0x7 << bit), ((priority & 0x7) << bit));
+}
+
+static inline void
+setup_dma_interrupt(unsigned lch,
+	void (*callback)(unsigned channel, u16 ch_status, void *data),
+	void *data)
+{
+	if (!callback) {
+		edma_shadow0_write_array(SH_IECR, lch >> 5,
+				(1 << (lch & 0x1f)));
+	}
+
+	intr_data[lch].callback = callback;
+	intr_data[lch].data = data;
+
+	if (callback) {
+		edma_shadow0_write_array(SH_ICR, lch >> 5,
+				(1 << (lch & 0x1f)));
+		edma_shadow0_write_array(SH_IESR, lch >> 5,
+				(1 << (lch & 0x1f)));
+	}
+}
+
+/******************************************************************************
+ *
+ * DMA interrupt handler
+ *
+ *****************************************************************************/
+static irqreturn_t dma_irq_handler(int irq, void *data)
+{
+	int i;
+	unsigned int cnt = 0;
+
+	dev_dbg(data, "dma_irq_handler\n");
+
+	if ((edma_shadow0_read_array(SH_IPR, 0) == 0)
+	    && (edma_shadow0_read_array(SH_IPR, 1) == 0))
+		return IRQ_NONE;
+
+	while (1) {
+		int j;
+		if (edma_shadow0_read_array(SH_IPR, 0))
+			j = 0;
+		else if (edma_shadow0_read_array(SH_IPR, 1))
+			j = 1;
+		else
+			break;
+		dev_dbg(data, "IPR%d %08x\n", j,
+				edma_shadow0_read_array(SH_IPR, j));
+		for (i = 0; i < 32; i++) {
+			int k = (j << 5) + i;
+			if (edma_shadow0_read_array(SH_IPR, j) & (1 << i)) {
+				/* Clear the corresponding IPR bits */
+				edma_shadow0_write_array(SH_ICR, j, (1 << i));
+				if (intr_data[k].callback) {
+					intr_data[k].callback(k, DMA_COMPLETE,
+						intr_data[k].data);
+				}
+			}
+		}
+		cnt++;
+		if (cnt > 10)
+			break;
+	}
+	edma_shadow0_write(SH_IEVAL, 1);
+	return IRQ_HANDLED;
+}
+
+/******************************************************************************
+ *
+ * DMA error interrupt handler
+ *
+ *****************************************************************************/
+static irqreturn_t dma_ccerr_handler(int irq, void *data)
+{
+	int i;
+	unsigned int cnt = 0;
+
+	dev_dbg(data, "dma_ccerr_handler\n");
+
+	if ((edma_read_array(EDMA_EMR, 0) == 0) &&
+	    (edma_read_array(EDMA_EMR, 1) == 0) &&
+	    (edma_read(EDMA_QEMR) == 0) && (edma_read(EDMA_CCERR) == 0))
+		return IRQ_NONE;
+
+	while (1) {
+		int j = -1;
+		if (edma_read_array(EDMA_EMR, 0))
+			j = 0;
+		else if (edma_read_array(EDMA_EMR, 1))
+			j = 1;
+		if (j >= 0) {
+			dev_dbg(data, "EMR%d %08x\n", j,
+					edma_read_array(EDMA_EMR, j));
+			for (i = 0; i < 32; i++) {
+				int k = (j << 5) + i;
+				if (edma_read_array(EDMA_EMR, j) & (1 << i)) {
+					/* Clear the corresponding EMR bits */
+					edma_write_array(EDMA_EMCR, j, 1 << i);
+					/* Clear any SER */
+					edma_shadow0_write_array(SH_SECR, j,
+							(1 << i));
+					if (intr_data[k].callback) {
+						intr_data[k].callback(k,
+								DMA_CC_ERROR,
+								intr_data
+								[k].data);
+					}
+				}
+			}
+		} else if (edma_read(EDMA_QEMR)) {
+			dev_dbg(data, "QEMR %02x\n",
+				edma_read(EDMA_QEMR));
+			for (i = 0; i < 8; i++) {
+				if (edma_read(EDMA_QEMR) & (1 << i)) {
+					/* Clear the corresponding IPR bits */
+					edma_write(EDMA_QEMCR, 1 << i);
+					edma_shadow0_write(SH_QSECR, (1 << i));
+
+					/* NOTE:  not reported!! */
+				}
+			}
+		} else if (edma_read(EDMA_CCERR)) {
+			dev_dbg(data, "CCERR %08x\n",
+				edma_read(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(EDMA_CCERR) & (1 << i)) {
+					/* Clear the corresponding IPR bits */
+					edma_write(EDMA_CCERRCLR, 1 << i);
+
+					/* NOTE:  not reported!! */
+				}
+			}
+		}
+		if ((edma_read_array(EDMA_EMR, 0) == 0)
+		    && (edma_read_array(EDMA_EMR, 1) == 0)
+		    && (edma_read(EDMA_QEMR) == 0)
+		    && (edma_read(EDMA_CCERR) == 0)) {
+			break;
+		}
+		cnt++;
+		if (cnt > 10)
+			break;
+	}
+	edma_write(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;
+}
+
+/*-----------------------------------------------------------------------*/
+
+/* 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)
+{
+	if (channel < 0) {
+		channel = 0;
+		for (;;) {
+			channel = find_next_bit(edma_noevent,
+					num_channels, channel);
+			if (channel == num_channels)
+				return -ENOMEM;
+			if (!test_and_set_bit(channel, edma_inuse))
+				break;
+			channel++;
+		}
+	} else if (channel >= num_channels) {
+		return -EINVAL;
+	} else if (test_and_set_bit(channel, edma_inuse)) {
+		return -EBUSY;
+	}
+
+	/* ensure access through shadow region 0 */
+	edma_or_array2(EDMA_DRAE, 0, channel >> 5, 1 << (channel & 0x1f));
+
+	/* ensure no events are pending */
+	edma_stop(channel);
+	memcpy_toio(edmacc_regs_base + PARM_OFFSET(channel),
+			&dummy_paramset, PARM_SIZE);
+
+	if (callback)
+		setup_dma_interrupt(channel, callback, data);
+
+	map_dmach_queue(channel, eventq_no);
+
+	return 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)
+{
+	if (channel >= num_channels)
+		return;
+
+	setup_dma_interrupt(channel, NULL, NULL);
+	/* REVISIT should probably take out of shadow region 0 */
+
+	memcpy_toio(edmacc_regs_base + PARM_OFFSET(channel),
+			&dummy_paramset, PARM_SIZE);
+	clear_bit(channel, 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(int slot)
+{
+	if (slot < 0) {
+		slot = num_channels;
+		for (;;) {
+			slot = find_next_zero_bit(edma_inuse,
+					num_slots, slot);
+			if (slot == num_slots)
+				return -ENOMEM;
+			if (!test_and_set_bit(slot, edma_inuse))
+				break;
+		}
+	} else if (slot < num_channels || slot >= num_slots) {
+		return -EINVAL;
+	} else if (test_and_set_bit(slot, edma_inuse)) {
+		return -EBUSY;
+	}
+
+	memcpy_toio(edmacc_regs_base + PARM_OFFSET(slot),
+			&dummy_paramset, PARM_SIZE);
+
+	return 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)
+{
+	if (slot < num_channels || slot >= num_slots)
+		return;
+
+	memcpy_toio(edmacc_regs_base + PARM_OFFSET(slot),
+			&dummy_paramset, PARM_SIZE);
+	clear_bit(slot, edma_inuse);
+}
+EXPORT_SYMBOL(edma_free_slot);
+
+/*-----------------------------------------------------------------------*/
+
+/* 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)
+{
+	if (slot < num_slots) {
+		unsigned int i = edma_parm_read(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(PARM_OPT, slot, i);
+
+		/* set the source port address
+		   in source register of param structure */
+		edma_parm_write(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)
+{
+	if (slot < num_slots) {
+		unsigned int i = edma_parm_read(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(PARM_OPT, slot, i);
+		/* set the destination port address
+		   in dest register of param structure */
+		edma_parm_write(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;
+
+	edma_read_slot(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)
+{
+	if (slot < num_slots) {
+		edma_parm_modify(PARM_SRC_DST_BIDX, slot,
+				0xffff0000, src_bidx);
+		edma_parm_modify(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)
+{
+	if (slot < num_slots) {
+		edma_parm_modify(PARM_SRC_DST_BIDX, slot,
+				0x0000ffff, dest_bidx << 16);
+		edma_parm_modify(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)
+{
+	if (slot < num_slots) {
+		edma_parm_modify(PARM_LINK_BCNTRLD, slot,
+				0x0000ffff, bcnt_rld << 16);
+		if (sync_mode == ASYNC)
+			edma_parm_and(PARM_OPT, slot, ~SYNCDIM);
+		else
+			edma_parm_or(PARM_OPT, slot, SYNCDIM);
+		/* Set the acount, bcount, ccount registers */
+		edma_parm_write(PARM_A_B_CNT, slot, (bcnt << 16) | acnt);
+		edma_parm_write(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)
+{
+	if (from >= num_slots)
+		return;
+	if (to >= num_slots)
+		return;
+	edma_parm_modify(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)
+{
+	if (from >= num_slots)
+		return;
+	edma_parm_or(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)
+{
+	if (slot >= num_slots)
+		return;
+	memcpy_toio(edmacc_regs_base + 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)
+{
+	if (slot >= num_slots)
+		return;
+	memcpy_fromio(param, edmacc_regs_base + 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)
+{
+	if (channel < num_channels) {
+		unsigned int mask = (1 << (channel & 0x1f));
+
+		edma_shadow0_write_array(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)
+{
+	if (channel < num_channels) {
+		unsigned int mask = (1 << (channel & 0x1f));
+
+		edma_shadow0_write_array(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)
+{
+	if (channel < num_channels) {
+		int j = channel >> 5;
+		unsigned int mask = (1 << (channel & 0x1f));
+
+		/* EDMA channels without event association */
+		if (test_bit(channel, edma_noevent)) {
+			pr_debug("EDMA: ESR%d %08x\n", j,
+				edma_shadow0_read_array(SH_ESR, j));
+			edma_shadow0_write_array(SH_ESR, j, mask);
+			return 0;
+		}
+
+		/* EDMA channel with event association */
+		pr_debug("EDMA: ER%d %08x\n", j,
+			edma_shadow0_read_array(SH_ER, j));
+		/* Clear any pending error */
+		edma_write_array(EDMA_EMCR, j, mask);
+		/* Clear any SER */
+		edma_shadow0_write_array(SH_SECR, j, mask);
+		edma_shadow0_write_array(SH_EESR, j, mask);
+		pr_debug("EDMA: EER%d %08x\n", j,
+			edma_shadow0_read_array(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)
+{
+	if (channel < num_channels) {
+		int j = channel >> 5;
+		unsigned int mask = (1 << (channel & 0x1f));
+
+		edma_shadow0_write_array(SH_EECR, j, mask);
+		edma_shadow0_write_array(SH_ECR, j, mask);
+		edma_shadow0_write_array(SH_SECR, j, mask);
+		edma_write_array(EDMA_EMCR, j, mask);
+
+		pr_debug("EDMA: EER%d %08x\n", j,
+				edma_shadow0_read_array(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)
+{
+	if (channel < num_channels) {
+		int j = (channel >> 5);
+		unsigned int mask = 1 << (channel & 0x1f);
+
+		pr_debug("EDMA: EMR%d %08x\n", j,
+				edma_read_array(EDMA_EMR, j));
+		edma_shadow0_write_array(SH_ECR, j, mask);
+		/* Clear the corresponding EMR bits */
+		edma_write_array(EDMA_EMCR, j, mask);
+		/* Clear any SER */
+		edma_shadow0_write_array(SH_SECR, j, mask);
+		edma_write(EDMA_CCERRCLR, (1 << 16) | 0x3);
+	}
+}
+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)
+{
+	if (channel >= num_channels)
+		return;
+	if (channel < 32)
+		edma_write(EDMA_ECR, 1 << channel);
+	else
+		edma_write(EDMA_ECRH, 1 << (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;
+	int			i;
+	int			status;
+	const s8		*noevent;
+	int			irq = 0, err_irq = 0;
+	struct resource		*r;
+	resource_size_t		len;
+
+	if (!info)
+		return -ENODEV;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "edma_cc");
+	if (!r)
+		return -ENODEV;
+
+	len = r->end - r->start + 1;
+
+	r = request_mem_region(r->start, len, r->name);
+	if (!r)
+		return -EBUSY;
+
+	edmacc_regs_base = ioremap(r->start, len);
+	if (!edmacc_regs_base) {
+		status = -EBUSY;
+		goto fail1;
+	}
+
+	num_channels = min_t(unsigned, info->n_channel, EDMA_MAX_DMACH);
+	num_slots = min_t(unsigned, info->n_slot, EDMA_MAX_PARAMENTRY);
+
+	dev_dbg(&pdev->dev, "DMA REG BASE ADDR=%p\n", edmacc_regs_base);
+
+	for (i = 0; i < num_slots; i++)
+		memcpy_toio(edmacc_regs_base + PARM_OFFSET(i),
+				&dummy_paramset, PARM_SIZE);
+
+	noevent = info->noevent;
+	if (noevent) {
+		while (*noevent != -1)
+			set_bit(*noevent++, edma_noevent);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	status = request_irq(irq, dma_irq_handler, 0, "edma", &pdev->dev);
+	if (status < 0) {
+		dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
+			irq, status);
+		goto fail;
+	}
+
+	err_irq = platform_get_irq(pdev, 1);
+	status = request_irq(err_irq, dma_ccerr_handler, 0,
+				"edma_error", &pdev->dev);
+	if (status < 0) {
+		dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
+			err_irq, status);
+		goto fail;
+	}
+
+	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;
+		}
+	}
+
+	/* Everything lives on transfer controller 1 until otherwise specified.
+	 * This way, long transfers on the low priority queue
+	 * started by the codec engine will not cause audio defects.
+	 */
+	for (i = 0; i < num_channels; i++)
+		map_dmach_queue(i, EVENTQ_1);
+
+	/* Event queue to TC mapping */
+	for (i = 0; queue_tc_mapping[i][0] != -1; i++)
+		map_queue_tc(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(queue_priority_mapping[i][0],
+					 queue_priority_mapping[i][1]);
+
+	for (i = 0; i < info->n_region; i++) {
+		edma_write_array2(EDMA_DRAE, i, 0, 0x0);
+		edma_write_array2(EDMA_DRAE, i, 1, 0x0);
+		edma_write_array(EDMA_QRAE, i, 0x0);
+	}
+
+	return 0;
+
+fail:
+	if (err_irq)
+		free_irq(err_irq, NULL);
+	if (irq)
+		free_irq(irq, NULL);
+	iounmap(edmacc_regs_base);
+fail1:
+	release_mem_region(r->start, len);
+	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);
+