bcm27xx: add support for linux v5.15

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 640 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0069-dmaengine-Add-support-for-BCM2708.patch b/target/linux/bcm27xx/patches-5.15/950-0069-dmaengine-Add-support-for-BCM2708.patch
new file mode 100644
index 0000000000..be7cc3d378
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0069-dmaengine-Add-support-for-BCM2708.patch
@@ -0,0 +1,640 @@
+From 75777d681d96172675877f9dd2c0b9df3bee50b9 Mon Sep 17 00:00:00 2001
+From: Florian Meier <florian.meier@koalo.de>
+Date: Fri, 22 Nov 2013 14:22:53 +0100
+Subject: [PATCH] dmaengine: Add support for BCM2708
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add support for DMA controller of BCM2708 as used in the Raspberry Pi.
+Currently it only supports cyclic DMA.
+
+Signed-off-by: Florian Meier <florian.meier@koalo.de>
+
+dmaengine: expand functionality by supporting scatter/gather transfers sdhci-bcm2708 and dma.c: fix for LITE channels
+
+DMA: fix cyclic LITE length overflow bug
+
+dmaengine: bcm2708: Remove chancnt affectations
+
+Mirror bcm2835-dma.c commit 9eba5536a7434c69d8c185d4bd1c70734d92287d:
+chancnt is already filled by dma_async_device_register, which uses the channel
+list to know how much channels there is.
+
+Since it's already filled, we can safely remove it from the drivers' probe
+function.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: overwrite dreq only if it is not set
+
+dreq is set when the DMA channel is fetched from Device Tree.
+slave_id is set using dmaengine_slave_config().
+Only overwrite dreq with slave_id if it is not set.
+
+dreq/slave_id in the cyclic DMA case is not touched, because I don't
+have hardware to test with.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: do device registration in the board file
+
+Don't register the device in the driver. Do it in the board file.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: don't restrict DT support to ARCH_BCM2835
+
+Both ARCH_BCM2835 and ARCH_BCM270x are built with OF now.
+Add Device Tree support to the non ARCH_BCM2835 case.
+Use the same driver name regardless of architecture.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+BCM270x_DT: add bcm2835-dma entry
+
+Add Device Tree entry for bcm2835-dma.
+The entry doesn't contain any resources since they are handled
+by the arch/arm/mach-bcm270x/dma.c driver.
+In non-DT mode, don't add the device in the board file.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+bcm2708-dmaengine: Add debug options
+
+BCM270x: Add memory and irq resources to dmaengine device and DT
+
+Prepare for merging of the legacy DMA API arch driver dma.c
+with bcm2708-dmaengine by adding memory and irq resources both
+to platform file device and Device Tree node.
+Don't use BCM_DMAMAN_DRIVER_NAME so we don't have to include mach/dma.h
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: Merge with arch dma.c driver and disable dma.c
+
+Merge the legacy DMA API driver with bcm2708-dmaengine.
+This is done so we can use bcm2708_fb on ARCH_BCM2835 (mailbox
+driver is also needed).
+
+Changes to the dma.c code:
+- Use BIT() macro.
+- Cutdown some comments to one line.
+- Add mutex to vc_dmaman and use this, since the dev lock is locked
+  during probing of the engine part.
+- Add global g_dmaman variable since drvdata is used by the engine part.
+- Restructure for readability:
+  vc_dmaman_chan_alloc()
+  vc_dmaman_chan_free()
+  bcm_dma_chan_free()
+- Restructure bcm_dma_chan_alloc() to simplify error handling.
+- Use device irq resources instead of hardcoded bcm_dma_irqs table.
+- Remove dev_dmaman_register() and code it directly.
+- Remove dev_dmaman_deregister() and code it directly.
+- Simplify bcm_dmaman_probe() using devm_* functions.
+- Get dmachans from DT if available.
+- Keep 'dma.dmachans' module argument name for backwards compatibility.
+
+Make it available on ARCH_BCM2835 as well.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: set residue_granularity field
+
+bcm2708-dmaengine supports residue reporting at burst level
+but didn't report this via the residue_granularity field.
+
+Without this field set properly we get playback issues with I2S cards.
+
+dmaengine: bcm2708-dmaengine: Fix memory leak when stopping a running transfer
+
+bcm2708-dmaengine: Use more DMA channels (but not 12)
+
+1) Only the bcm2708_fb drivers uses the legacy DMA API, and
+it requires a BULK-capable channel, so all other types
+(FAST, NORMAL and LITE) can be made available to the regular
+DMA API.
+
+2) DMA channels 11-14 share an interrupt. The driver can't
+handle this, so don't use channels 12-14 (12 was used, probably
+because it appears to have an interrupt, but in reality that
+interrupt is for activity on ANY channel). This may explain
+a lockup encountered when running out of DMA channels.
+
+The combined effect of this patch is to leave 7 DMA channels
+available + channel 0 for bcm2708_fb via the legacy API.
+
+See: https://github.com/raspberrypi/linux/issues/1110
+     https://github.com/raspberrypi/linux/issues/1108
+
+dmaengine: bcm2708: Make legacy API available for bcm2835-dma
+
+bcm2708_fb uses the legacy DMA API, so in order to start using
+bcm2835-dma, bcm2835-dma has to support the legacy API. Make this
+possible by exporting bcm_dmaman_probe() and bcm_dmaman_remove().
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: Change DT compatible string
+
+Both bcm2835-dma and bcm2708-dmaengine have the same compatible string.
+So change compatible to "brcm,bcm2708-dma".
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+dmaengine: bcm2708: Remove driver but keep legacy API
+
+Dropping non-DT support means we don't need this driver,
+but we still need the legacy DMA API.
+
+Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
+
+bcm2708-dmaengine - Fix arm64 portability/build issues
+
+dma-bcm2708: Fix module compilation of CONFIG_DMA_BCM2708
+
+bcm2708-dmaengine.c defines functions like bcm_dma_start which are
+defined as well in dma-bcm2708.h as inline versions when
+CONFIG_DMA_BCM2708 is not defined. This works fine when
+CONFIG_DMA_BCM2708 is built in, but when it is selected as module build
+fails with redefinition errors because in the build system when
+CONFIG_DMA_BCM2708 is selected as module, the macro becomes
+CONFIG_DMA_BCM2708_MODULE.
+
+This patch makes the header use CONFIG_DMA_BCM2708_MODULE too when
+available.
+
+Fixes https://github.com/raspberrypi/linux/issues/2056
+
+Signed-off-by: Andrei Gherzan <andrei@gherzan.com>
+---
+ drivers/dma/Kconfig                       |   6 +-
+ drivers/dma/Makefile                      |   1 +
+ drivers/dma/bcm2708-dmaengine.c           | 281 ++++++++++++++++++++++
+ include/linux/platform_data/dma-bcm2708.h | 143 +++++++++++
+ 4 files changed, 430 insertions(+), 1 deletion(-)
+ create mode 100644 drivers/dma/bcm2708-dmaengine.c
+ create mode 100644 include/linux/platform_data/dma-bcm2708.h
+
+--- a/drivers/dma/Kconfig
++++ b/drivers/dma/Kconfig
+@@ -127,7 +127,7 @@ config BCM_SBA_RAID
+ 
+ config DMA_BCM2835
+ 	tristate "BCM2835 DMA engine support"
+-	depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709
++	depends on ARCH_BCM2835
+ 	select DMA_ENGINE
+ 	select DMA_VIRTUAL_CHANNELS
+ 
+@@ -683,6 +683,10 @@ config UNIPHIER_XDMAC
+ 	  UniPhier platform. This DMA controller can transfer data from
+ 	  memory to memory, memory to peripheral and peripheral to memory.
+ 
++config DMA_BCM2708
++	tristate "BCM2708 DMA legacy API support"
++	depends on DMA_BCM2835
++
+ config XGENE_DMA
+ 	tristate "APM X-Gene DMA support"
+ 	depends on ARCH_XGENE || COMPILE_TEST
+--- a/drivers/dma/Makefile
++++ b/drivers/dma/Makefile
+@@ -21,6 +21,7 @@ obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
+ obj-$(CONFIG_AT_XDMAC) += at_xdmac.o
+ obj-$(CONFIG_AXI_DMAC) += dma-axi-dmac.o
+ obj-$(CONFIG_BCM_SBA_RAID) += bcm-sba-raid.o
++obj-$(CONFIG_DMA_BCM2708) += bcm2708-dmaengine.o
+ obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
+ obj-$(CONFIG_DMA_JZ4780) += dma-jz4780.o
+ obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
+--- /dev/null
++++ b/drivers/dma/bcm2708-dmaengine.c
+@@ -0,0 +1,281 @@
++/*
++ * BCM2708 legacy DMA API
++ *
++ * 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.
++ */
++
++#include <linux/init.h>
++#include <linux/interrupt.h>
++#include <linux/list.h>
++#include <linux/module.h>
++#include <linux/platform_data/dma-bcm2708.h>
++#include <linux/platform_device.h>
++#include <linux/slab.h>
++#include <linux/io.h>
++#include <linux/spinlock.h>
++
++#include "virt-dma.h"
++
++#define CACHE_LINE_MASK 31
++#define DEFAULT_DMACHAN_BITMAP 0x10  /* channel 4 only */
++
++/* valid only for channels 0 - 14, 15 has its own base address */
++#define BCM2708_DMA_CHAN(n)	((n) << 8) /* base address */
++#define BCM2708_DMA_CHANIO(dma_base, n) \
++	((void __iomem *)((char *)(dma_base) + BCM2708_DMA_CHAN(n)))
++
++struct vc_dmaman {
++	void __iomem *dma_base;
++	u32 chan_available; /* bitmap of available channels */
++	u32 has_feature[BCM_DMA_FEATURE_COUNT]; /* bitmap of feature presence */
++	struct mutex lock;
++};
++
++static struct device *dmaman_dev;	/* we assume there's only one! */
++static struct vc_dmaman *g_dmaman;	/* DMA manager */
++
++/* DMA Auxiliary Functions */
++
++/* A DMA buffer on an arbitrary boundary may separate a cache line into a
++   section inside the DMA buffer and another section outside it.
++   Even if we flush DMA buffers from the cache there is always the chance that
++   during a DMA someone will access the part of a cache line that is outside
++   the DMA buffer - which will then bring in unwelcome data.
++   Without being able to dictate our own buffer pools we must insist that
++   DMA buffers consist of a whole number of cache lines.
++*/
++extern int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len)
++{
++	int i;
++
++	for (i = 0; i < sg_len; i++) {
++		if (sg_ptr[i].offset & CACHE_LINE_MASK ||
++		    sg_ptr[i].length & CACHE_LINE_MASK)
++			return 0;
++	}
++
++	return 1;
++}
++EXPORT_SYMBOL_GPL(bcm_sg_suitable_for_dma);
++
++extern void bcm_dma_start(void __iomem *dma_chan_base,
++			  dma_addr_t control_block)
++{
++	dsb(sy);	/* ARM data synchronization (push) operation */
++
++	writel(control_block, dma_chan_base + BCM2708_DMA_ADDR);
++	writel(BCM2708_DMA_ACTIVE, dma_chan_base + BCM2708_DMA_CS);
++}
++EXPORT_SYMBOL_GPL(bcm_dma_start);
++
++extern void bcm_dma_wait_idle(void __iomem *dma_chan_base)
++{
++	dsb(sy);
++
++	/* ugly busy wait only option for now */
++	while (readl(dma_chan_base + BCM2708_DMA_CS) & BCM2708_DMA_ACTIVE)
++		cpu_relax();
++}
++EXPORT_SYMBOL_GPL(bcm_dma_wait_idle);
++
++extern bool bcm_dma_is_busy(void __iomem *dma_chan_base)
++{
++	dsb(sy);
++
++	return readl(dma_chan_base + BCM2708_DMA_CS) & BCM2708_DMA_ACTIVE;
++}
++EXPORT_SYMBOL_GPL(bcm_dma_is_busy);
++
++/* Complete an ongoing DMA (assuming its results are to be ignored)
++   Does nothing if there is no DMA in progress.
++   This routine waits for the current AXI transfer to complete before
++   terminating the current DMA. If the current transfer is hung on a DREQ used
++   by an uncooperative peripheral the AXI transfer may never complete.	In this
++   case the routine times out and return a non-zero error code.
++   Use of this routine doesn't guarantee that the ongoing or aborted DMA
++   does not produce an interrupt.
++*/
++extern int bcm_dma_abort(void __iomem *dma_chan_base)
++{
++	unsigned long int cs;
++	int rc = 0;
++
++	cs = readl(dma_chan_base + BCM2708_DMA_CS);
++
++	if (BCM2708_DMA_ACTIVE & cs) {
++		long int timeout = 10000;
++
++		/* write 0 to the active bit - pause the DMA */
++		writel(0, dma_chan_base + BCM2708_DMA_CS);
++
++		/* wait for any current AXI transfer to complete */
++		while (0 != (cs & BCM2708_DMA_ISPAUSED) && --timeout >= 0)
++			cs = readl(dma_chan_base + BCM2708_DMA_CS);
++
++		if (0 != (cs & BCM2708_DMA_ISPAUSED)) {
++			/* we'll un-pause when we set of our next DMA */
++			rc = -ETIMEDOUT;
++
++		} else if (BCM2708_DMA_ACTIVE & cs) {
++			/* terminate the control block chain */
++			writel(0, dma_chan_base + BCM2708_DMA_NEXTCB);
++
++			/* abort the whole DMA */
++			writel(BCM2708_DMA_ABORT | BCM2708_DMA_ACTIVE,
++			       dma_chan_base + BCM2708_DMA_CS);
++		}
++	}
++
++	return rc;
++}
++EXPORT_SYMBOL_GPL(bcm_dma_abort);
++
++ /* DMA Manager Device Methods */
++
++static void vc_dmaman_init(struct vc_dmaman *dmaman, void __iomem *dma_base,
++			   u32 chans_available)
++{
++	dmaman->dma_base = dma_base;
++	dmaman->chan_available = chans_available;
++	dmaman->has_feature[BCM_DMA_FEATURE_FAST_ORD] = 0x0c;  /* 2 & 3 */
++	dmaman->has_feature[BCM_DMA_FEATURE_BULK_ORD] = 0x01;  /* 0 */
++	dmaman->has_feature[BCM_DMA_FEATURE_NORMAL_ORD] = 0xfe;  /* 1 to 7 */
++	dmaman->has_feature[BCM_DMA_FEATURE_LITE_ORD] = 0x7f00;  /* 8 to 14 */
++}
++
++static int vc_dmaman_chan_alloc(struct vc_dmaman *dmaman,
++				unsigned required_feature_set)
++{
++	u32 chans;
++	int chan = 0;
++	int feature;
++
++	chans = dmaman->chan_available;
++	for (feature = 0; feature < BCM_DMA_FEATURE_COUNT; feature++)
++		/* select the subset of available channels with the desired
++		   features */
++		if (required_feature_set & (1 << feature))
++			chans &= dmaman->has_feature[feature];
++
++	if (!chans)
++		return -ENOENT;
++
++	/* return the ordinal of the first channel in the bitmap */
++	while (chans != 0 && (chans & 1) == 0) {
++		chans >>= 1;
++		chan++;
++	}
++	/* claim the channel */
++	dmaman->chan_available &= ~(1 << chan);
++
++	return chan;
++}
++
++static int vc_dmaman_chan_free(struct vc_dmaman *dmaman, int chan)
++{
++	if (chan < 0)
++		return -EINVAL;
++
++	if ((1 << chan) & dmaman->chan_available)
++		return -EIDRM;
++
++	dmaman->chan_available |= (1 << chan);
++
++	return 0;
++}
++
++/* DMA Manager Monitor */
++
++extern int bcm_dma_chan_alloc(unsigned required_feature_set,
++			      void __iomem **out_dma_base, int *out_dma_irq)
++{
++	struct vc_dmaman *dmaman = g_dmaman;
++	struct platform_device *pdev = to_platform_device(dmaman_dev);
++	struct resource *r;
++	int chan;
++
++	if (!dmaman_dev)
++		return -ENODEV;
++
++	mutex_lock(&dmaman->lock);
++	chan = vc_dmaman_chan_alloc(dmaman, required_feature_set);
++	if (chan < 0)
++		goto out;
++
++	r = platform_get_resource(pdev, IORESOURCE_IRQ, (unsigned int)chan);
++	if (!r) {
++		dev_err(dmaman_dev, "failed to get irq for DMA channel %d\n",
++			chan);
++		vc_dmaman_chan_free(dmaman, chan);
++		chan = -ENOENT;
++		goto out;
++	}
++
++	*out_dma_base = BCM2708_DMA_CHANIO(dmaman->dma_base, chan);
++	*out_dma_irq = r->start;
++	dev_dbg(dmaman_dev,
++		"Legacy API allocated channel=%d, base=%p, irq=%i\n",
++		chan, *out_dma_base, *out_dma_irq);
++
++out:
++	mutex_unlock(&dmaman->lock);
++
++	return chan;
++}
++EXPORT_SYMBOL_GPL(bcm_dma_chan_alloc);
++
++extern int bcm_dma_chan_free(int channel)
++{
++	struct vc_dmaman *dmaman = g_dmaman;
++	int rc;
++
++	if (!dmaman_dev)
++		return -ENODEV;
++
++	mutex_lock(&dmaman->lock);
++	rc = vc_dmaman_chan_free(dmaman, channel);
++	mutex_unlock(&dmaman->lock);
++
++	return rc;
++}
++EXPORT_SYMBOL_GPL(bcm_dma_chan_free);
++
++int bcm_dmaman_probe(struct platform_device *pdev, void __iomem *base,
++		     u32 chans_available)
++{
++	struct device *dev = &pdev->dev;
++	struct vc_dmaman *dmaman;
++
++	dmaman = devm_kzalloc(dev, sizeof(*dmaman), GFP_KERNEL);
++	if (!dmaman)
++		return -ENOMEM;
++
++	mutex_init(&dmaman->lock);
++	vc_dmaman_init(dmaman, base, chans_available);
++	g_dmaman = dmaman;
++	dmaman_dev = dev;
++
++	dev_info(dev, "DMA legacy API manager, dmachans=0x%x\n",
++		 chans_available);
++
++	return 0;
++}
++EXPORT_SYMBOL(bcm_dmaman_probe);
++
++int bcm_dmaman_remove(struct platform_device *pdev)
++{
++	dmaman_dev = NULL;
++
++	return 0;
++}
++EXPORT_SYMBOL(bcm_dmaman_remove);
++
++MODULE_LICENSE("GPL");
+--- /dev/null
++++ b/include/linux/platform_data/dma-bcm2708.h
+@@ -0,0 +1,143 @@
++/*
++ *  Copyright (C) 2010 Broadcom
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++
++#ifndef _PLAT_BCM2708_DMA_H
++#define _PLAT_BCM2708_DMA_H
++
++/* DMA CS Control and Status bits */
++#define BCM2708_DMA_ACTIVE	BIT(0)
++#define BCM2708_DMA_INT		BIT(2)
++#define BCM2708_DMA_ISPAUSED	BIT(4)  /* Pause requested or not active */
++#define BCM2708_DMA_ISHELD	BIT(5)  /* Is held by DREQ flow control */
++#define BCM2708_DMA_ERR		BIT(8)
++#define BCM2708_DMA_ABORT	BIT(30) /* stop current CB, go to next, WO */
++#define BCM2708_DMA_RESET	BIT(31) /* WO, self clearing */
++
++/* DMA control block "info" field bits */
++#define BCM2708_DMA_INT_EN	BIT(0)
++#define BCM2708_DMA_TDMODE	BIT(1)
++#define BCM2708_DMA_WAIT_RESP	BIT(3)
++#define BCM2708_DMA_D_INC	BIT(4)
++#define BCM2708_DMA_D_WIDTH	BIT(5)
++#define BCM2708_DMA_D_DREQ	BIT(6)
++#define BCM2708_DMA_S_INC	BIT(8)
++#define BCM2708_DMA_S_WIDTH	BIT(9)
++#define BCM2708_DMA_S_DREQ	BIT(10)
++
++#define	BCM2708_DMA_BURST(x)	(((x) & 0xf) << 12)
++#define	BCM2708_DMA_PER_MAP(x)	((x) << 16)
++#define	BCM2708_DMA_WAITS(x)	(((x) & 0x1f) << 21)
++
++#define BCM2708_DMA_DREQ_EMMC	11
++#define BCM2708_DMA_DREQ_SDHOST	13
++
++#define BCM2708_DMA_CS		0x00 /* Control and Status */
++#define BCM2708_DMA_ADDR	0x04
++/* the current control block appears in the following registers - read only */
++#define BCM2708_DMA_INFO	0x08
++#define BCM2708_DMA_SOURCE_AD	0x0c
++#define BCM2708_DMA_DEST_AD	0x10
++#define BCM2708_DMA_NEXTCB	0x1C
++#define BCM2708_DMA_DEBUG	0x20
++
++#define BCM2708_DMA4_CS		(BCM2708_DMA_CHAN(4) + BCM2708_DMA_CS)
++#define BCM2708_DMA4_ADDR	(BCM2708_DMA_CHAN(4) + BCM2708_DMA_ADDR)
++
++#define BCM2708_DMA_TDMODE_LEN(w, h) ((h) << 16 | (w))
++
++/* When listing features we can ask for when allocating DMA channels give
++   those with higher priority smaller ordinal numbers */
++#define BCM_DMA_FEATURE_FAST_ORD	0
++#define BCM_DMA_FEATURE_BULK_ORD	1
++#define BCM_DMA_FEATURE_NORMAL_ORD	2
++#define BCM_DMA_FEATURE_LITE_ORD	3
++#define BCM_DMA_FEATURE_FAST		BIT(BCM_DMA_FEATURE_FAST_ORD)
++#define BCM_DMA_FEATURE_BULK		BIT(BCM_DMA_FEATURE_BULK_ORD)
++#define BCM_DMA_FEATURE_NORMAL		BIT(BCM_DMA_FEATURE_NORMAL_ORD)
++#define BCM_DMA_FEATURE_LITE		BIT(BCM_DMA_FEATURE_LITE_ORD)
++#define BCM_DMA_FEATURE_COUNT		4
++
++struct bcm2708_dma_cb {
++	u32 info;
++	u32 src;
++	u32 dst;
++	u32 length;
++	u32 stride;
++	u32 next;
++	u32 pad[2];
++};
++
++struct scatterlist;
++struct platform_device;
++
++#if defined(CONFIG_DMA_BCM2708) || defined(CONFIG_DMA_BCM2708_MODULE)
++
++int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len);
++void bcm_dma_start(void __iomem *dma_chan_base, dma_addr_t control_block);
++void bcm_dma_wait_idle(void __iomem *dma_chan_base);
++bool bcm_dma_is_busy(void __iomem *dma_chan_base);
++int bcm_dma_abort(void __iomem *dma_chan_base);
++
++/* return channel no or -ve error */
++int bcm_dma_chan_alloc(unsigned preferred_feature_set,
++		       void __iomem **out_dma_base, int *out_dma_irq);
++int bcm_dma_chan_free(int channel);
++
++int bcm_dmaman_probe(struct platform_device *pdev, void __iomem *base,
++		     u32 chans_available);
++int bcm_dmaman_remove(struct platform_device *pdev);
++
++#else /* CONFIG_DMA_BCM2708 */
++
++static inline int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr,
++					  int sg_len)
++{
++	return 0;
++}
++
++static inline void bcm_dma_start(void __iomem *dma_chan_base,
++				 dma_addr_t control_block) { }
++
++static inline void bcm_dma_wait_idle(void __iomem *dma_chan_base) { }
++
++static inline bool bcm_dma_is_busy(void __iomem *dma_chan_base)
++{
++	return false;
++}
++
++static inline int bcm_dma_abort(void __iomem *dma_chan_base)
++{
++	return -EINVAL;
++}
++
++static inline int bcm_dma_chan_alloc(unsigned preferred_feature_set,
++				     void __iomem **out_dma_base,
++				     int *out_dma_irq)
++{
++	return -EINVAL;
++}
++
++static inline int bcm_dma_chan_free(int channel)
++{
++	return -EINVAL;
++}
++
++static inline int bcm_dmaman_probe(struct platform_device *pdev,
++				   void __iomem *base, u32 chans_available)
++{
++	return 0;
++}
++
++static inline int bcm_dmaman_remove(struct platform_device *pdev)
++{
++	return 0;
++}
++
++#endif /* CONFIG_DMA_BCM2708 || CONFIG_DMA_BCM2708_MODULE */
++
++#endif /* _PLAT_BCM2708_DMA_H */