xtensa: s6000 dma engine support

There are four slightly different dma engines on the s6000 family.
One for memory-memory transfers, the other three for memory-device.

This patch implements a platform-specific kernel-API to control these
engines.  It is needed for the network, video, audio peripherals on
s6000.

Signed-off-by: Oskar Schirmer <os@emlix.com>
Signed-off-by: Daniel Glockner <dg@emlix.com>
Signed-off-by: Fabian Godehardt <fg@emlix.com>
Cc: Daniel Glockner <dg@emlix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Zankel <chris@zankel.net>

3 files changed, 561 insertions, 1 deletions

diff --git a/arch/xtensa/variants/s6000/Makefile b/arch/xtensa/variants/s6000/Makefile
index d83f3805130c..3e7ef0a0c498 100644
--- a/arch/xtensa/variants/s6000/Makefile
+++ b/arch/xtensa/variants/s6000/Makefile
@@ -1,4 +1,4 @@
 # s6000 Makefile
 
-obj-y		+= irq.o gpio.o
+obj-y		+= irq.o gpio.o dmac.o
 obj-$(CONFIG_XTENSA_CALIBRATE_CCOUNT)	+= delay.o
diff --git a/arch/xtensa/variants/s6000/dmac.c b/arch/xtensa/variants/s6000/dmac.c
new file mode 100644
index 000000000000..dc7f7c573518
--- /dev/null
+++ b/arch/xtensa/variants/s6000/dmac.c
@@ -0,0 +1,173 @@
+/*
+ * Authors:	Oskar Schirmer <os@emlix.com>
+ *		Daniel Gloeckner <dg@emlix.com>
+ * (c) 2008 emlix GmbH http://www.emlix.com
+ *
+ * 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/kernel.h>
+#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/spinlock.h>
+#include <asm/cacheflush.h>
+#include <variant/dmac.h>
+
+/* DMA engine lookup */
+
+struct s6dmac_ctrl s6dmac_ctrl[S6_DMAC_NB];
+
+
+/* DMA control, per engine */
+
+void s6dmac_put_fifo_cache(u32 dmac, int chan, u32 src, u32 dst, u32 size)
+{
+	if (xtensa_need_flush_dma_source(src)) {
+		u32 base = src;
+		u32 span = size;
+		u32 chunk = readl(DMA_CHNL(dmac, chan) + S6_DMA_CMONCHUNK);
+		if (chunk && (size > chunk)) {
+			s32 skip =
+				readl(DMA_CHNL(dmac, chan) + S6_DMA_SRCSKIP);
+			u32 gaps = (size+chunk-1)/chunk - 1;
+			if (skip >= 0) {
+				span += gaps * skip;
+			} else if (-skip > chunk) {
+				s32 decr = gaps * (chunk + skip);
+				base += decr;
+				span = chunk - decr;
+			} else {
+				span = max(span + gaps * skip,
+					(chunk + skip) * gaps - skip);
+			}
+		}
+		flush_dcache_unaligned(base, span);
+	}
+	if (xtensa_need_invalidate_dma_destination(dst)) {
+		u32 base = dst;
+		u32 span = size;
+		u32 chunk = readl(DMA_CHNL(dmac, chan) + S6_DMA_CMONCHUNK);
+		if (chunk && (size > chunk)) {
+			s32 skip =
+				readl(DMA_CHNL(dmac, chan) + S6_DMA_DSTSKIP);
+			u32 gaps = (size+chunk-1)/chunk - 1;
+			if (skip >= 0) {
+				span += gaps * skip;
+			} else if (-skip > chunk) {
+				s32 decr = gaps * (chunk + skip);
+				base += decr;
+				span = chunk - decr;
+			} else {
+				span = max(span + gaps * skip,
+					(chunk + skip) * gaps - skip);
+			}
+		}
+		invalidate_dcache_unaligned(base, span);
+	}
+	s6dmac_put_fifo(dmac, chan, src, dst, size);
+}
+
+void s6dmac_disable_error_irqs(u32 dmac, u32 mask)
+{
+	unsigned long flags;
+	spinlock_t *spinl = &s6dmac_ctrl[_dmac_addr_index(dmac)].lock;
+	spin_lock_irqsave(spinl, flags);
+	_s6dmac_disable_error_irqs(dmac, mask);
+	spin_unlock_irqrestore(spinl, flags);
+}
+
+u32 s6dmac_int_sources(u32 dmac, u32 channel)
+{
+	u32 mask, ret, tmp;
+	mask = 1 << channel;
+
+	tmp = readl(dmac + S6_DMA_TERMCNTIRQSTAT);
+	tmp &= mask;
+	writel(tmp, dmac + S6_DMA_TERMCNTIRQCLR);
+	ret = tmp >> channel;
+
+	tmp = readl(dmac + S6_DMA_PENDCNTIRQSTAT);
+	tmp &= mask;
+	writel(tmp, dmac + S6_DMA_PENDCNTIRQCLR);
+	ret |= (tmp >> channel) << 1;
+
+	tmp = readl(dmac + S6_DMA_LOWWMRKIRQSTAT);
+	tmp &= mask;
+	writel(tmp, dmac + S6_DMA_LOWWMRKIRQCLR);
+	ret |= (tmp >> channel) << 2;
+
+	tmp = readl(dmac + S6_DMA_INTRAW0);
+	tmp &= (mask << S6_DMA_INT0_OVER) | (mask << S6_DMA_INT0_UNDER);
+	writel(tmp, dmac + S6_DMA_INTCLEAR0);
+
+	if (tmp & (mask << S6_DMA_INT0_UNDER))
+		ret |= 1 << 3;
+	if (tmp & (mask << S6_DMA_INT0_OVER))
+		ret |= 1 << 4;
+
+	tmp = readl(dmac + S6_DMA_MASTERERRINFO);
+	mask <<= S6_DMA_INT1_CHANNEL;
+	if (((tmp >> S6_DMA_MASTERERR_CHAN(0)) & S6_DMA_MASTERERR_CHAN_MASK)
+			== channel)
+		mask |= 1 << S6_DMA_INT1_MASTER;
+	if (((tmp >> S6_DMA_MASTERERR_CHAN(1)) & S6_DMA_MASTERERR_CHAN_MASK)
+			== channel)
+		mask |= 1 << (S6_DMA_INT1_MASTER + 1);
+	if (((tmp >> S6_DMA_MASTERERR_CHAN(2)) & S6_DMA_MASTERERR_CHAN_MASK)
+			== channel)
+		mask |= 1 << (S6_DMA_INT1_MASTER + 2);
+
+	tmp = readl(dmac + S6_DMA_INTRAW1) & mask;
+	writel(tmp, dmac + S6_DMA_INTCLEAR1);
+	ret |= ((tmp >> channel) & 1) << 5;
+	ret |= ((tmp >> S6_DMA_INT1_MASTER) & S6_DMA_INT1_MASTER_MASK) << 6;
+
+	return ret;
+}
+
+void s6dmac_release_chan(u32 dmac, int chan)
+{
+	if (chan >= 0)
+		s6dmac_disable_chan(dmac, chan);
+}
+
+
+/* global init */
+
+static inline void __init dmac_init(u32 dmac, u8 chan_nb)
+{
+	s6dmac_ctrl[S6_DMAC_INDEX(dmac)].dmac = dmac;
+	spin_lock_init(&s6dmac_ctrl[S6_DMAC_INDEX(dmac)].lock);
+	s6dmac_ctrl[S6_DMAC_INDEX(dmac)].chan_nb = chan_nb;
+	writel(S6_DMA_INT1_MASTER_MASK << S6_DMA_INT1_MASTER,
+		dmac + S6_DMA_INTCLEAR1);
+}
+
+static inline void __init dmac_master(u32 dmac,
+	u32 m0start, u32 m0end, u32 m1start, u32 m1end)
+{
+	writel(m0start, dmac + S6_DMA_MASTER0START);
+	writel(m0end - 1, dmac + S6_DMA_MASTER0END);
+	writel(m1start, dmac + S6_DMA_MASTER1START);
+	writel(m1end - 1, dmac + S6_DMA_MASTER1END);
+}
+
+static void __init s6_dmac_init(void)
+{
+	dmac_init(S6_REG_LMSDMA, S6_LMSDMA_NB);
+	dmac_master(S6_REG_LMSDMA,
+		S6_MEM_DDR, S6_MEM_PCIE_APER, S6_MEM_EFI, S6_MEM_GMAC);
+	dmac_init(S6_REG_NIDMA, S6_NIDMA_NB);
+	dmac_init(S6_REG_DPDMA, S6_DPDMA_NB);
+	dmac_master(S6_REG_DPDMA,
+		S6_MEM_DDR, S6_MEM_PCIE_APER, S6_REG_DP, S6_REG_DPDMA);
+	dmac_init(S6_REG_HIFDMA, S6_HIFDMA_NB);
+	dmac_master(S6_REG_HIFDMA,
+		S6_MEM_GMAC, S6_MEM_PCIE_CFG, S6_MEM_PCIE_APER, S6_MEM_AUX);
+}
+
+arch_initcall(s6_dmac_init);
diff --git a/arch/xtensa/variants/s6000/include/variant/dmac.h b/arch/xtensa/variants/s6000/include/variant/dmac.h
new file mode 100644
index 000000000000..89ab9484fb71
--- /dev/null
+++ b/arch/xtensa/variants/s6000/include/variant/dmac.h
@@ -0,0 +1,387 @@
+/*
+ * include/asm-xtensa/variant-s6000/dmac.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2006 Tensilica Inc.
+ * Copyright (C) 2008 Emlix GmbH <info@emlix.com>
+ * Authors:	Fabian Godehardt <fg@emlix.com>
+ *		Oskar Schirmer <os@emlix.com>
+ *		Daniel Gloeckner <dg@emlix.com>
+ */
+
+#ifndef __ASM_XTENSA_S6000_DMAC_H
+#define __ASM_XTENSA_S6000_DMAC_H
+#include <linux/io.h>
+#include <variant/hardware.h>
+
+/* DMA global */
+
+#define S6_DMA_INTSTAT0		0x000
+#define S6_DMA_INTSTAT1		0x004
+#define S6_DMA_INTENABLE0	0x008
+#define S6_DMA_INTENABLE1	0x00C
+#define S6_DMA_INTRAW0		0x010
+#define S6_DMA_INTRAW1		0x014
+#define S6_DMA_INTCLEAR0	0x018
+#define S6_DMA_INTCLEAR1	0x01C
+#define S6_DMA_INTSET0		0x020
+#define S6_DMA_INTSET1		0x024
+#define S6_DMA_INT0_UNDER		0
+#define S6_DMA_INT0_OVER		16
+#define S6_DMA_INT1_CHANNEL		0
+#define S6_DMA_INT1_MASTER		16
+#define S6_DMA_INT1_MASTER_MASK			7
+#define S6_DMA_TERMCNTIRQSTAT	0x028
+#define S6_DMA_TERMCNTIRQCLR	0x02C
+#define S6_DMA_TERMCNTIRQSET	0x030
+#define S6_DMA_PENDCNTIRQSTAT	0x034
+#define S6_DMA_PENDCNTIRQCLR	0x038
+#define S6_DMA_PENDCNTIRQSET	0x03C
+#define S6_DMA_LOWWMRKIRQSTAT	0x040
+#define S6_DMA_LOWWMRKIRQCLR	0x044
+#define S6_DMA_LOWWMRKIRQSET	0x048
+#define S6_DMA_MASTERERRINFO	0x04C
+#define S6_DMA_MASTERERR_CHAN(n)	(4*(n))
+#define S6_DMA_MASTERERR_CHAN_MASK		0xF
+#define S6_DMA_DESCRFIFO0	0x050
+#define S6_DMA_DESCRFIFO1	0x054
+#define S6_DMA_DESCRFIFO2	0x058
+#define S6_DMA_DESCRFIFO2_AUTODISABLE	24
+#define S6_DMA_DESCRFIFO3	0x05C
+#define S6_DMA_MASTER0START	0x060
+#define S6_DMA_MASTER0END	0x064
+#define S6_DMA_MASTER1START	0x068
+#define S6_DMA_MASTER1END	0x06C
+#define S6_DMA_NEXTFREE		0x070
+#define S6_DMA_NEXTFREE_CHAN		0
+#define S6_DMA_NEXTFREE_CHAN_MASK	0x1F
+#define S6_DMA_NEXTFREE_ENA		16
+#define S6_DMA_NEXTFREE_ENA_MASK	((1 << 16) - 1)
+#define S6_DMA_DPORTCTRLGRP(p)	((p) * 4 + 0x074)
+#define S6_DMA_DPORTCTRLGRP_FRAMEREP	0
+#define S6_DMA_DPORTCTRLGRP_NRCHANS	1
+#define S6_DMA_DPORTCTRLGRP_NRCHANS_1		0
+#define S6_DMA_DPORTCTRLGRP_NRCHANS_3		1
+#define S6_DMA_DPORTCTRLGRP_NRCHANS_4		2
+#define S6_DMA_DPORTCTRLGRP_NRCHANS_2		3
+#define S6_DMA_DPORTCTRLGRP_ENA		31
+
+
+/* DMA per channel */
+
+#define DMA_CHNL(dmac, n)	((dmac) + 0x1000 + (n) * 0x100)
+#define DMA_INDEX_CHNL(addr)	(((addr) >> 8) & 0xF)
+#define DMA_MASK_DMAC(addr)	((addr) & 0xFFFF0000)
+#define S6_DMA_CHNCTRL		0x000
+#define S6_DMA_CHNCTRL_ENABLE		0
+#define S6_DMA_CHNCTRL_PAUSE		1
+#define S6_DMA_CHNCTRL_PRIO		2
+#define S6_DMA_CHNCTRL_PRIO_MASK		3
+#define S6_DMA_CHNCTRL_PERIPHXFER	4
+#define S6_DMA_CHNCTRL_PERIPHENA	5
+#define S6_DMA_CHNCTRL_SRCINC		6
+#define S6_DMA_CHNCTRL_DSTINC		7
+#define S6_DMA_CHNCTRL_BURSTLOG		8
+#define S6_DMA_CHNCTRL_BURSTLOG_MASK		7
+#define S6_DMA_CHNCTRL_DESCFIFODEPTH	12
+#define S6_DMA_CHNCTRL_DESCFIFODEPTH_MASK	0x1F
+#define S6_DMA_CHNCTRL_DESCFIFOFULL	17
+#define S6_DMA_CHNCTRL_BWCONSEL		18
+#define S6_DMA_CHNCTRL_BWCONENA		19
+#define S6_DMA_CHNCTRL_PENDGCNTSTAT	20
+#define S6_DMA_CHNCTRL_PENDGCNTSTAT_MASK	0x3F
+#define S6_DMA_CHNCTRL_LOWWMARK		26
+#define S6_DMA_CHNCTRL_LOWWMARK_MASK		0xF
+#define S6_DMA_CHNCTRL_TSTAMP		30
+#define S6_DMA_TERMCNTNB	0x004
+#define S6_DMA_TERMCNTNB_MASK			0xFFFF
+#define S6_DMA_TERMCNTTMO	0x008
+#define S6_DMA_TERMCNTSTAT	0x00C
+#define S6_DMA_TERMCNTSTAT_MASK		0xFF
+#define S6_DMA_CMONCHUNK	0x010
+#define S6_DMA_SRCSKIP		0x014
+#define S6_DMA_DSTSKIP		0x018
+#define S6_DMA_CUR_SRC		0x024
+#define S6_DMA_CUR_DST		0x028
+#define S6_DMA_TIMESTAMP	0x030
+
+/* DMA channel lists */
+
+#define S6_DPDMA_CHAN(stream, channel)	(4 * (stream) + (channel))
+#define S6_DPDMA_NB	16
+
+#define S6_HIFDMA_GMACTX	0
+#define S6_HIFDMA_GMACRX	1
+#define S6_HIFDMA_I2S0		2
+#define S6_HIFDMA_I2S1		3
+#define S6_HIFDMA_EGIB		4
+#define S6_HIFDMA_PCITX		5
+#define S6_HIFDMA_PCIRX		6
+#define S6_HIFDMA_NB	7
+
+#define S6_NIDMA_NB	4
+
+#define S6_LMSDMA_NB	12
+
+/* controller access */
+
+#define S6_DMAC_NB	4
+#define S6_DMAC_INDEX(dmac)	(((unsigned)(dmac) >> 18) % S6_DMAC_NB)
+
+struct s6dmac_ctrl {
+	u32 dmac;
+	spinlock_t lock;
+	u8 chan_nb;
+};
+
+extern struct s6dmac_ctrl s6dmac_ctrl[S6_DMAC_NB];
+
+
+/* DMA control, per channel */
+
+static inline int s6dmac_fifo_full(u32 dmac, int chan)
+{
+	return (readl(DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL)
+		& (1 << S6_DMA_CHNCTRL_DESCFIFOFULL)) && 1;
+}
+
+static inline int s6dmac_termcnt_irq(u32 dmac, int chan)
+{
+	u32 m = 1 << chan;
+	int r = (readl(dmac + S6_DMA_TERMCNTIRQSTAT) & m) && 1;
+	if (r)
+		writel(m, dmac + S6_DMA_TERMCNTIRQCLR);
+	return r;
+}
+
+static inline int s6dmac_pendcnt_irq(u32 dmac, int chan)
+{
+	u32 m = 1 << chan;
+	int r = (readl(dmac + S6_DMA_PENDCNTIRQSTAT) & m) && 1;
+	if (r)
+		writel(m, dmac + S6_DMA_PENDCNTIRQCLR);
+	return r;
+}
+
+static inline int s6dmac_lowwmark_irq(u32 dmac, int chan)
+{
+	int r = (readl(dmac + S6_DMA_LOWWMRKIRQSTAT) & (1 << chan)) ? 1 : 0;
+	if (r)
+		writel(1 << chan, dmac + S6_DMA_LOWWMRKIRQCLR);
+	return r;
+}
+
+static inline u32 s6dmac_pending_count(u32 dmac, int chan)
+{
+	return (readl(DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL)
+			>> S6_DMA_CHNCTRL_PENDGCNTSTAT)
+		& S6_DMA_CHNCTRL_PENDGCNTSTAT_MASK;
+}
+
+static inline void s6dmac_set_terminal_count(u32 dmac, int chan, u32 n)
+{
+	n &= S6_DMA_TERMCNTNB_MASK;
+	n |= readl(DMA_CHNL(dmac, chan) + S6_DMA_TERMCNTNB)
+	      & ~S6_DMA_TERMCNTNB_MASK;
+	writel(n, DMA_CHNL(dmac, chan) + S6_DMA_TERMCNTNB);
+}
+
+static inline u32 s6dmac_get_terminal_count(u32 dmac, int chan)
+{
+	return (readl(DMA_CHNL(dmac, chan) + S6_DMA_TERMCNTNB))
+		& S6_DMA_TERMCNTNB_MASK;
+}
+
+static inline u32 s6dmac_timestamp(u32 dmac, int chan)
+{
+	return readl(DMA_CHNL(dmac, chan) + S6_DMA_TIMESTAMP);
+}
+
+static inline u32 s6dmac_cur_src(u32 dmac, int chan)
+{
+	return readl(DMA_CHNL(dmac, chan) + S6_DMA_CUR_SRC);
+}
+
+static inline u32 s6dmac_cur_dst(u32 dmac, int chan)
+{
+	return readl(DMA_CHNL(dmac, chan) + S6_DMA_CUR_DST);
+}
+
+static inline void s6dmac_disable_chan(u32 dmac, int chan)
+{
+	u32 ctrl;
+	writel(readl(DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL)
+		& ~(1 << S6_DMA_CHNCTRL_ENABLE),
+		DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL);
+	do
+		ctrl = readl(DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL);
+	while (ctrl & (1 << S6_DMA_CHNCTRL_ENABLE));
+}
+
+static inline void s6dmac_set_stride_skip(u32 dmac, int chan,
+	int comchunk,		/* 0: disable scatter/gather */
+	int srcskip, int dstskip)
+{
+	writel(comchunk, DMA_CHNL(dmac, chan) + S6_DMA_CMONCHUNK);
+	writel(srcskip, DMA_CHNL(dmac, chan) + S6_DMA_SRCSKIP);
+	writel(dstskip, DMA_CHNL(dmac, chan) + S6_DMA_DSTSKIP);
+}
+
+static inline void s6dmac_enable_chan(u32 dmac, int chan,
+	int prio,               /* 0 (highest) .. 3 (lowest) */
+	int periphxfer,         /* <0: disable p.req.line, 0..1: mode */
+	int srcinc, int dstinc, /* 0: dont increment src/dst address */
+	int comchunk,		/* 0: disable scatter/gather */
+	int srcskip, int dstskip,
+	int burstsize,		/* 4 for I2S, 7 for everything else */
+	int bandwidthconserve,  /* <0: disable, 0..1: select */
+	int lowwmark,           /* 0..15 */
+	int timestamp,		/* 0: disable timestamp */
+	int enable)		/* 0: disable for now */
+{
+	writel(1, DMA_CHNL(dmac, chan) + S6_DMA_TERMCNTNB);
+	writel(0, DMA_CHNL(dmac, chan) + S6_DMA_TERMCNTTMO);
+	writel(lowwmark << S6_DMA_CHNCTRL_LOWWMARK,
+		DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL);
+	s6dmac_set_stride_skip(dmac, chan, comchunk, srcskip, dstskip);
+	writel(((enable ? 1 : 0) << S6_DMA_CHNCTRL_ENABLE) |
+		(prio << S6_DMA_CHNCTRL_PRIO) |
+		(((periphxfer > 0) ? 1 : 0) << S6_DMA_CHNCTRL_PERIPHXFER) |
+		(((periphxfer < 0) ? 0 : 1) << S6_DMA_CHNCTRL_PERIPHENA) |
+		((srcinc ? 1 : 0) << S6_DMA_CHNCTRL_SRCINC) |
+		((dstinc ? 1 : 0) << S6_DMA_CHNCTRL_DSTINC) |
+		(burstsize << S6_DMA_CHNCTRL_BURSTLOG) |
+		(((bandwidthconserve > 0) ? 1 : 0) << S6_DMA_CHNCTRL_BWCONSEL) |
+		(((bandwidthconserve < 0) ? 0 : 1) << S6_DMA_CHNCTRL_BWCONENA) |
+		(lowwmark << S6_DMA_CHNCTRL_LOWWMARK) |
+		((timestamp ? 1 : 0) << S6_DMA_CHNCTRL_TSTAMP),
+		DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL);
+}
+
+
+/* DMA control, per engine */
+
+static inline unsigned _dmac_addr_index(u32 dmac)
+{
+	unsigned i = S6_DMAC_INDEX(dmac);
+	if (s6dmac_ctrl[i].dmac != dmac)
+		BUG();
+	return i;
+}
+
+static inline void _s6dmac_disable_error_irqs(u32 dmac, u32 mask)
+{
+	writel(mask, dmac + S6_DMA_TERMCNTIRQCLR);
+	writel(mask, dmac + S6_DMA_PENDCNTIRQCLR);
+	writel(mask, dmac + S6_DMA_LOWWMRKIRQCLR);
+	writel(readl(dmac + S6_DMA_INTENABLE0)
+		& ~((mask << S6_DMA_INT0_UNDER) | (mask << S6_DMA_INT0_OVER)),
+		dmac + S6_DMA_INTENABLE0);
+	writel(readl(dmac + S6_DMA_INTENABLE1) & ~(mask << S6_DMA_INT1_CHANNEL),
+		dmac + S6_DMA_INTENABLE1);
+	writel((mask << S6_DMA_INT0_UNDER) | (mask << S6_DMA_INT0_OVER),
+		dmac + S6_DMA_INTCLEAR0);
+	writel(mask << S6_DMA_INT1_CHANNEL, dmac + S6_DMA_INTCLEAR1);
+}
+
+/*
+ * request channel from specified engine
+ * with chan<0, accept any channel
+ * further parameters see s6dmac_enable_chan
+ * returns < 0 upon error, channel nb otherwise
+ */
+static inline int s6dmac_request_chan(u32 dmac, int chan,
+	int prio,
+	int periphxfer,
+	int srcinc, int dstinc,
+	int comchunk,
+	int srcskip, int dstskip,
+	int burstsize,
+	int bandwidthconserve,
+	int lowwmark,
+	int timestamp,
+	int enable)
+{
+	int r = chan;
+	unsigned long flags;
+	spinlock_t *spinl = &s6dmac_ctrl[_dmac_addr_index(dmac)].lock;
+	spin_lock_irqsave(spinl, flags);
+	if (r < 0) {
+		r = (readl(dmac + S6_DMA_NEXTFREE) >> S6_DMA_NEXTFREE_CHAN)
+			& S6_DMA_NEXTFREE_CHAN_MASK;
+	}
+	if (r >= s6dmac_ctrl[_dmac_addr_index(dmac)].chan_nb) {
+		if (chan < 0)
+			r = -EBUSY;
+		else
+			r = -ENXIO;
+	} else if (((readl(dmac + S6_DMA_NEXTFREE) >> S6_DMA_NEXTFREE_ENA)
+			>> r) & 1) {
+		r = -EBUSY;
+	} else {
+		s6dmac_enable_chan(dmac, r, prio, periphxfer,
+			srcinc, dstinc, comchunk, srcskip, dstskip, burstsize,
+			bandwidthconserve, lowwmark, timestamp, enable);
+	}
+	spin_unlock_irqrestore(spinl, flags);
+	return r;
+}
+
+static inline void s6dmac_put_fifo(u32 dmac, int chan,
+	u32 src, u32 dst, u32 size)
+{
+	unsigned long flags;
+	spinlock_t *spinl = &s6dmac_ctrl[_dmac_addr_index(dmac)].lock;
+	spin_lock_irqsave(spinl, flags);
+	writel(src, dmac + S6_DMA_DESCRFIFO0);
+	writel(dst, dmac + S6_DMA_DESCRFIFO1);
+	writel(size, dmac + S6_DMA_DESCRFIFO2);
+	writel(chan, dmac + S6_DMA_DESCRFIFO3);
+	spin_unlock_irqrestore(spinl, flags);
+}
+
+static inline u32 s6dmac_channel_enabled(u32 dmac, int chan)
+{
+	return readl(DMA_CHNL(dmac, chan) + S6_DMA_CHNCTRL) &
+			(1 << S6_DMA_CHNCTRL_ENABLE);
+}
+
+/*
+ * group 1-4 data port channels
+ * with port=0..3, nrch=1-4 channels,
+ * frrep=0/1 (dis- or enable frame repeat)
+ */
+static inline void s6dmac_dp_setup_group(u32 dmac, int port,
+			int nrch, int frrep)
+{
+	const static u8 mask[4] = {0, 3, 1, 2};
+	BUG_ON(dmac != S6_REG_DPDMA);
+	if ((port < 0) || (port > 3) || (nrch < 1) || (nrch > 4))
+		return;
+	writel((mask[nrch - 1] << S6_DMA_DPORTCTRLGRP_NRCHANS)
+		| ((frrep ? 1 : 0) << S6_DMA_DPORTCTRLGRP_FRAMEREP),
+		dmac + S6_DMA_DPORTCTRLGRP(port));
+}
+
+static inline void s6dmac_dp_switch_group(u32 dmac, int port, int enable)
+{
+	u32 tmp;
+	BUG_ON(dmac != S6_REG_DPDMA);
+	tmp = readl(dmac + S6_DMA_DPORTCTRLGRP(port));
+	if (enable)
+		tmp |= (1 << S6_DMA_DPORTCTRLGRP_ENA);
+	else
+		tmp &= ~(1 << S6_DMA_DPORTCTRLGRP_ENA);
+	writel(tmp, dmac + S6_DMA_DPORTCTRLGRP(port));
+}
+
+extern void s6dmac_put_fifo_cache(u32 dmac, int chan,
+	u32 src, u32 dst, u32 size);
+extern void s6dmac_disable_error_irqs(u32 dmac, u32 mask);
+extern u32 s6dmac_int_sources(u32 dmac, u32 channel);
+extern void s6dmac_release_chan(u32 dmac, int chan);
+
+#endif /* __ASM_XTENSA_S6000_DMAC_H */