Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 882 insertions, 0 deletions

diff --git a/arch/arm/mach-omap1/omap-dma.c b/arch/arm/mach-omap1/omap-dma.c
new file mode 100644
index 0000000000..9ee472f8ea
--- /dev/null
+++ b/arch/arm/mach-omap1/omap-dma.c
@@ -0,0 +1,882 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/plat-omap/dma.c
+ *
+ * Copyright (C) 2003 - 2008 Nokia Corporation
+ * Author: Juha Yrjölä <juha.yrjola@nokia.com>
+ * DMA channel linking for 1610 by Samuel Ortiz <samuel.ortiz@nokia.com>
+ * Graphics DMA and LCD DMA graphics tranformations
+ * by Imre Deak <imre.deak@nokia.com>
+ * OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
+ * Merged to support both OMAP1 and OMAP2 by Tony Lindgren <tony@atomide.com>
+ * Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
+ *
+ * Copyright (C) 2009 Texas Instruments
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * Support functions for the OMAP internal DMA channels.
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - https://www.ti.com/
+ * Converted DMA library into DMA platform driver.
+ *	- G, Manjunath Kondaiah <manjugk@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+#include <linux/omap-dma.h>
+
+#include <linux/soc/ti/omap1-io.h>
+#include <linux/soc/ti/omap1-soc.h>
+
+#include "tc.h"
+
+/*
+ * MAX_LOGICAL_DMA_CH_COUNT: the maximum number of logical DMA
+ * channels that an instance of the SDMA IP block can support.  Used
+ * to size arrays.  (The actual maximum on a particular SoC may be less
+ * than this -- for example, OMAP1 SDMA instances only support 17 logical
+ * DMA channels.)
+ */
+#define MAX_LOGICAL_DMA_CH_COUNT		32
+
+#undef DEBUG
+
+#define OMAP_DMA_ACTIVE			0x01
+
+#define OMAP_FUNC_MUX_ARM_BASE		(0xfffe1000 + 0xec)
+
+static struct omap_system_dma_plat_info *p;
+static struct omap_dma_dev_attr *d;
+static int enable_1510_mode;
+static u32 errata;
+
+struct dma_link_info {
+	int *linked_dmach_q;
+	int no_of_lchs_linked;
+
+	int q_count;
+	int q_tail;
+	int q_head;
+
+	int chain_state;
+	int chain_mode;
+
+};
+
+static int dma_lch_count;
+static int dma_chan_count;
+static int omap_dma_reserve_channels;
+
+static DEFINE_SPINLOCK(dma_chan_lock);
+static struct omap_dma_lch *dma_chan;
+
+static inline void omap_disable_channel_irq(int lch)
+{
+	/* disable channel interrupts */
+	p->dma_write(0, CICR, lch);
+	/* Clear CSR */
+	p->dma_read(CSR, lch);
+}
+
+static inline void set_gdma_dev(int req, int dev)
+{
+	u32 reg = OMAP_FUNC_MUX_ARM_BASE + ((req - 1) / 5) * 4;
+	int shift = ((req - 1) % 5) * 6;
+	u32 l;
+
+	l = omap_readl(reg);
+	l &= ~(0x3f << shift);
+	l |= (dev - 1) << shift;
+	omap_writel(l, reg);
+}
+
+#if IS_ENABLED(CONFIG_FB_OMAP)
+void omap_set_dma_priority(int lch, int dst_port, int priority)
+{
+	unsigned long reg;
+	u32 l;
+
+	if (dma_omap1()) {
+		switch (dst_port) {
+		case OMAP_DMA_PORT_OCP_T1:	/* FFFECC00 */
+			reg = OMAP_TC_OCPT1_PRIOR;
+			break;
+		case OMAP_DMA_PORT_OCP_T2:	/* FFFECCD0 */
+			reg = OMAP_TC_OCPT2_PRIOR;
+			break;
+		case OMAP_DMA_PORT_EMIFF:	/* FFFECC08 */
+			reg = OMAP_TC_EMIFF_PRIOR;
+			break;
+		case OMAP_DMA_PORT_EMIFS:	/* FFFECC04 */
+			reg = OMAP_TC_EMIFS_PRIOR;
+			break;
+		default:
+			BUG();
+			return;
+		}
+		l = omap_readl(reg);
+		l &= ~(0xf << 8);
+		l |= (priority & 0xf) << 8;
+		omap_writel(l, reg);
+	}
+}
+EXPORT_SYMBOL(omap_set_dma_priority);
+#endif
+
+#if IS_ENABLED(CONFIG_USB_OMAP)
+#ifdef CONFIG_ARCH_OMAP15XX
+/* Returns 1 if the DMA module is in OMAP1510-compatible mode, 0 otherwise */
+static int omap_dma_in_1510_mode(void)
+{
+	return enable_1510_mode;
+}
+#else
+#define omap_dma_in_1510_mode()		0
+#endif
+
+void omap_set_dma_transfer_params(int lch, int data_type, int elem_count,
+				  int frame_count, int sync_mode,
+				  int dma_trigger, int src_or_dst_synch)
+{
+	u32 l;
+	u16 ccr;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~0x03;
+	l |= data_type;
+	p->dma_write(l, CSDP, lch);
+
+	ccr = p->dma_read(CCR, lch);
+	ccr &= ~(1 << 5);
+	if (sync_mode == OMAP_DMA_SYNC_FRAME)
+		ccr |= 1 << 5;
+	p->dma_write(ccr, CCR, lch);
+
+	ccr = p->dma_read(CCR2, lch);
+	ccr &= ~(1 << 2);
+	if (sync_mode == OMAP_DMA_SYNC_BLOCK)
+		ccr |= 1 << 2;
+	p->dma_write(ccr, CCR2, lch);
+	p->dma_write(elem_count, CEN, lch);
+	p->dma_write(frame_count, CFN, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_transfer_params);
+
+void omap_set_dma_channel_mode(int lch, enum omap_dma_channel_mode mode)
+{
+	if (!dma_omap15xx()) {
+		u32 l;
+
+		l = p->dma_read(LCH_CTRL, lch);
+		l &= ~0x7;
+		l |= mode;
+		p->dma_write(l, LCH_CTRL, lch);
+	}
+}
+EXPORT_SYMBOL(omap_set_dma_channel_mode);
+
+/* Note that src_port is only for omap1 */
+void omap_set_dma_src_params(int lch, int src_port, int src_amode,
+			     unsigned long src_start,
+			     int src_ei, int src_fi)
+{
+	u32 l;
+	u16 w;
+
+	w = p->dma_read(CSDP, lch);
+	w &= ~(0x1f << 2);
+	w |= src_port << 2;
+	p->dma_write(w, CSDP, lch);
+
+	l = p->dma_read(CCR, lch);
+	l &= ~(0x03 << 12);
+	l |= src_amode << 12;
+	p->dma_write(l, CCR, lch);
+
+	p->dma_write(src_start, CSSA, lch);
+
+	p->dma_write(src_ei, CSEI, lch);
+	p->dma_write(src_fi, CSFI, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_src_params);
+
+void omap_set_dma_src_data_pack(int lch, int enable)
+{
+	u32 l;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~(1 << 6);
+	if (enable)
+		l |= (1 << 6);
+	p->dma_write(l, CSDP, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_src_data_pack);
+
+void omap_set_dma_src_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
+{
+	unsigned int burst = 0;
+	u32 l;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~(0x03 << 7);
+
+	switch (burst_mode) {
+	case OMAP_DMA_DATA_BURST_DIS:
+		break;
+	case OMAP_DMA_DATA_BURST_4:
+		burst = 0x2;
+		break;
+	case OMAP_DMA_DATA_BURST_8:
+		/*
+		 * not supported by current hardware on OMAP1
+		 * w |= (0x03 << 7);
+		 */
+		fallthrough;
+	case OMAP_DMA_DATA_BURST_16:
+		/* OMAP1 don't support burst 16 */
+		fallthrough;
+	default:
+		BUG();
+	}
+
+	l |= (burst << 7);
+	p->dma_write(l, CSDP, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_src_burst_mode);
+
+/* Note that dest_port is only for OMAP1 */
+void omap_set_dma_dest_params(int lch, int dest_port, int dest_amode,
+			      unsigned long dest_start,
+			      int dst_ei, int dst_fi)
+{
+	u32 l;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~(0x1f << 9);
+	l |= dest_port << 9;
+	p->dma_write(l, CSDP, lch);
+
+	l = p->dma_read(CCR, lch);
+	l &= ~(0x03 << 14);
+	l |= dest_amode << 14;
+	p->dma_write(l, CCR, lch);
+
+	p->dma_write(dest_start, CDSA, lch);
+
+	p->dma_write(dst_ei, CDEI, lch);
+	p->dma_write(dst_fi, CDFI, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_dest_params);
+
+void omap_set_dma_dest_data_pack(int lch, int enable)
+{
+	u32 l;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~(1 << 13);
+	if (enable)
+		l |= 1 << 13;
+	p->dma_write(l, CSDP, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_dest_data_pack);
+
+void omap_set_dma_dest_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
+{
+	unsigned int burst = 0;
+	u32 l;
+
+	l = p->dma_read(CSDP, lch);
+	l &= ~(0x03 << 14);
+
+	switch (burst_mode) {
+	case OMAP_DMA_DATA_BURST_DIS:
+		break;
+	case OMAP_DMA_DATA_BURST_4:
+		burst = 0x2;
+		break;
+	case OMAP_DMA_DATA_BURST_8:
+		burst = 0x3;
+		break;
+	case OMAP_DMA_DATA_BURST_16:
+		/* OMAP1 don't support burst 16 */
+		fallthrough;
+	default:
+		printk(KERN_ERR "Invalid DMA burst mode\n");
+		BUG();
+		return;
+	}
+	l |= (burst << 14);
+	p->dma_write(l, CSDP, lch);
+}
+EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
+
+static inline void omap_enable_channel_irq(int lch)
+{
+	/* Clear CSR */
+	p->dma_read(CSR, lch);
+
+	/* Enable some nice interrupts. */
+	p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
+}
+
+void omap_disable_dma_irq(int lch, u16 bits)
+{
+	dma_chan[lch].enabled_irqs &= ~bits;
+}
+EXPORT_SYMBOL(omap_disable_dma_irq);
+
+static inline void enable_lnk(int lch)
+{
+	u32 l;
+
+	l = p->dma_read(CLNK_CTRL, lch);
+
+	l &= ~(1 << 14);
+
+	/* Set the ENABLE_LNK bits */
+	if (dma_chan[lch].next_lch != -1)
+		l = dma_chan[lch].next_lch | (1 << 15);
+
+	p->dma_write(l, CLNK_CTRL, lch);
+}
+
+static inline void disable_lnk(int lch)
+{
+	u32 l;
+
+	l = p->dma_read(CLNK_CTRL, lch);
+
+	/* Disable interrupts */
+	omap_disable_channel_irq(lch);
+
+	/* Set the STOP_LNK bit */
+	l |= 1 << 14;
+
+	p->dma_write(l, CLNK_CTRL, lch);
+	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
+}
+#endif
+
+int omap_request_dma(int dev_id, const char *dev_name,
+		     void (*callback)(int lch, u16 ch_status, void *data),
+		     void *data, int *dma_ch_out)
+{
+	int ch, free_ch = -1;
+	unsigned long flags;
+	struct omap_dma_lch *chan;
+
+	WARN(strcmp(dev_name, "DMA engine"), "Using deprecated platform DMA API - please update to DMA engine");
+
+	spin_lock_irqsave(&dma_chan_lock, flags);
+	for (ch = 0; ch < dma_chan_count; ch++) {
+		if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
+			free_ch = ch;
+			/* Exit after first free channel found */
+			break;
+		}
+	}
+	if (free_ch == -1) {
+		spin_unlock_irqrestore(&dma_chan_lock, flags);
+		return -EBUSY;
+	}
+	chan = dma_chan + free_ch;
+	chan->dev_id = dev_id;
+
+	if (p->clear_lch_regs)
+		p->clear_lch_regs(free_ch);
+
+	spin_unlock_irqrestore(&dma_chan_lock, flags);
+
+	chan->dev_name = dev_name;
+	chan->callback = callback;
+	chan->data = data;
+	chan->flags = 0;
+
+	chan->enabled_irqs = OMAP_DMA_DROP_IRQ | OMAP_DMA_BLOCK_IRQ;
+
+	chan->enabled_irqs |= OMAP1_DMA_TOUT_IRQ;
+
+	if (dma_omap16xx()) {
+		/* If the sync device is set, configure it dynamically. */
+		if (dev_id != 0) {
+			set_gdma_dev(free_ch + 1, dev_id);
+			dev_id = free_ch + 1;
+		}
+		/*
+		 * Disable the 1510 compatibility mode and set the sync device
+		 * id.
+		 */
+		p->dma_write(dev_id | (1 << 10), CCR, free_ch);
+	} else {
+		p->dma_write(dev_id, CCR, free_ch);
+	}
+
+	*dma_ch_out = free_ch;
+
+	return 0;
+}
+EXPORT_SYMBOL(omap_request_dma);
+
+void omap_free_dma(int lch)
+{
+	unsigned long flags;
+
+	if (dma_chan[lch].dev_id == -1) {
+		pr_err("omap_dma: trying to free unallocated DMA channel %d\n",
+		       lch);
+		return;
+	}
+
+	/* Disable all DMA interrupts for the channel. */
+	omap_disable_channel_irq(lch);
+
+	/* Make sure the DMA transfer is stopped. */
+	p->dma_write(0, CCR, lch);
+
+	spin_lock_irqsave(&dma_chan_lock, flags);
+	dma_chan[lch].dev_id = -1;
+	dma_chan[lch].next_lch = -1;
+	dma_chan[lch].callback = NULL;
+	spin_unlock_irqrestore(&dma_chan_lock, flags);
+}
+EXPORT_SYMBOL(omap_free_dma);
+
+/*
+ * Clears any DMA state so the DMA engine is ready to restart with new buffers
+ * through omap_start_dma(). Any buffers in flight are discarded.
+ */
+static void omap_clear_dma(int lch)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	p->clear_dma(lch);
+	local_irq_restore(flags);
+}
+
+#if IS_ENABLED(CONFIG_USB_OMAP)
+void omap_start_dma(int lch)
+{
+	u32 l;
+
+	/*
+	 * The CPC/CDAC register needs to be initialized to zero
+	 * before starting dma transfer.
+	 */
+	if (dma_omap15xx())
+		p->dma_write(0, CPC, lch);
+	else
+		p->dma_write(0, CDAC, lch);
+
+	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
+		int next_lch, cur_lch;
+		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
+
+		/* Set the link register of the first channel */
+		enable_lnk(lch);
+
+		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
+		dma_chan_link_map[lch] = 1;
+
+		cur_lch = dma_chan[lch].next_lch;
+		do {
+			next_lch = dma_chan[cur_lch].next_lch;
+
+			/* The loop case: we've been here already */
+			if (dma_chan_link_map[cur_lch])
+				break;
+			/* Mark the current channel */
+			dma_chan_link_map[cur_lch] = 1;
+
+			enable_lnk(cur_lch);
+			omap_enable_channel_irq(cur_lch);
+
+			cur_lch = next_lch;
+		} while (next_lch != -1);
+	} else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS))
+		p->dma_write(lch, CLNK_CTRL, lch);
+
+	omap_enable_channel_irq(lch);
+
+	l = p->dma_read(CCR, lch);
+
+	if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING))
+			l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
+	l |= OMAP_DMA_CCR_EN;
+
+	/*
+	 * As dma_write() uses IO accessors which are weakly ordered, there
+	 * is no guarantee that data in coherent DMA memory will be visible
+	 * to the DMA device.  Add a memory barrier here to ensure that any
+	 * such data is visible prior to enabling DMA.
+	 */
+	mb();
+	p->dma_write(l, CCR, lch);
+
+	dma_chan[lch].flags |= OMAP_DMA_ACTIVE;
+}
+EXPORT_SYMBOL(omap_start_dma);
+
+void omap_stop_dma(int lch)
+{
+	u32 l;
+
+	/* Disable all interrupts on the channel */
+	omap_disable_channel_irq(lch);
+
+	l = p->dma_read(CCR, lch);
+	if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&
+			(l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
+		int i = 0;
+		u32 sys_cf;
+
+		/* Configure No-Standby */
+		l = p->dma_read(OCP_SYSCONFIG, lch);
+		sys_cf = l;
+		l &= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
+		l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
+		p->dma_write(l , OCP_SYSCONFIG, 0);
+
+		l = p->dma_read(CCR, lch);
+		l &= ~OMAP_DMA_CCR_EN;
+		p->dma_write(l, CCR, lch);
+
+		/* Wait for sDMA FIFO drain */
+		l = p->dma_read(CCR, lch);
+		while (i < 100 && (l & (OMAP_DMA_CCR_RD_ACTIVE |
+					OMAP_DMA_CCR_WR_ACTIVE))) {
+			udelay(5);
+			i++;
+			l = p->dma_read(CCR, lch);
+		}
+		if (i >= 100)
+			pr_err("DMA drain did not complete on lch %d\n", lch);
+		/* Restore OCP_SYSCONFIG */
+		p->dma_write(sys_cf, OCP_SYSCONFIG, lch);
+	} else {
+		l &= ~OMAP_DMA_CCR_EN;
+		p->dma_write(l, CCR, lch);
+	}
+
+	/*
+	 * Ensure that data transferred by DMA is visible to any access
+	 * after DMA has been disabled.  This is important for coherent
+	 * DMA regions.
+	 */
+	mb();
+
+	if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
+		int next_lch, cur_lch = lch;
+		char dma_chan_link_map[MAX_LOGICAL_DMA_CH_COUNT];
+
+		memset(dma_chan_link_map, 0, sizeof(dma_chan_link_map));
+		do {
+			/* The loop case: we've been here already */
+			if (dma_chan_link_map[cur_lch])
+				break;
+			/* Mark the current channel */
+			dma_chan_link_map[cur_lch] = 1;
+
+			disable_lnk(cur_lch);
+
+			next_lch = dma_chan[cur_lch].next_lch;
+			cur_lch = next_lch;
+		} while (next_lch != -1);
+	}
+
+	dma_chan[lch].flags &= ~OMAP_DMA_ACTIVE;
+}
+EXPORT_SYMBOL(omap_stop_dma);
+
+/*
+ * Allows changing the DMA callback function or data. This may be needed if
+ * the driver shares a single DMA channel for multiple dma triggers.
+ */
+/*
+ * Returns current physical source address for the given DMA channel.
+ * If the channel is running the caller must disable interrupts prior calling
+ * this function and process the returned value before re-enabling interrupt to
+ * prevent races with the interrupt handler. Note that in continuous mode there
+ * is a chance for CSSA_L register overflow between the two reads resulting
+ * in incorrect return value.
+ */
+dma_addr_t omap_get_dma_src_pos(int lch)
+{
+	dma_addr_t offset = 0;
+
+	if (dma_omap15xx())
+		offset = p->dma_read(CPC, lch);
+	else
+		offset = p->dma_read(CSAC, lch);
+
+	if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0)
+		offset = p->dma_read(CSAC, lch);
+
+	if (!dma_omap15xx()) {
+		/*
+		 * CDAC == 0 indicates that the DMA transfer on the channel has
+		 * not been started (no data has been transferred so far).
+		 * Return the programmed source start address in this case.
+		 */
+		if (likely(p->dma_read(CDAC, lch)))
+			offset = p->dma_read(CSAC, lch);
+		else
+			offset = p->dma_read(CSSA, lch);
+	}
+
+	offset |= (p->dma_read(CSSA, lch) & 0xFFFF0000);
+
+	return offset;
+}
+EXPORT_SYMBOL(omap_get_dma_src_pos);
+
+/*
+ * Returns current physical destination address for the given DMA channel.
+ * If the channel is running the caller must disable interrupts prior calling
+ * this function and process the returned value before re-enabling interrupt to
+ * prevent races with the interrupt handler. Note that in continuous mode there
+ * is a chance for CDSA_L register overflow between the two reads resulting
+ * in incorrect return value.
+ */
+dma_addr_t omap_get_dma_dst_pos(int lch)
+{
+	dma_addr_t offset = 0;
+
+	if (dma_omap15xx())
+		offset = p->dma_read(CPC, lch);
+	else
+		offset = p->dma_read(CDAC, lch);
+
+	/*
+	 * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is
+	 * read before the DMA controller finished disabling the channel.
+	 */
+	if (!dma_omap15xx() && offset == 0) {
+		offset = p->dma_read(CDAC, lch);
+		/*
+		 * CDAC == 0 indicates that the DMA transfer on the channel has
+		 * not been started (no data has been transferred so far).
+		 * Return the programmed destination start address in this case.
+		 */
+		if (unlikely(!offset))
+			offset = p->dma_read(CDSA, lch);
+	}
+
+	offset |= (p->dma_read(CDSA, lch) & 0xFFFF0000);
+
+	return offset;
+}
+EXPORT_SYMBOL(omap_get_dma_dst_pos);
+
+int omap_get_dma_active_status(int lch)
+{
+	return (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN) != 0;
+}
+EXPORT_SYMBOL(omap_get_dma_active_status);
+#endif
+
+int omap_dma_running(void)
+{
+	int lch;
+
+	if (omap_lcd_dma_running())
+		return 1;
+
+	for (lch = 0; lch < dma_chan_count; lch++)
+		if (p->dma_read(CCR, lch) & OMAP_DMA_CCR_EN)
+			return 1;
+
+	return 0;
+}
+
+/*----------------------------------------------------------------------------*/
+
+static int omap1_dma_handle_ch(int ch)
+{
+	u32 csr;
+
+	if (enable_1510_mode && ch >= 6) {
+		csr = dma_chan[ch].saved_csr;
+		dma_chan[ch].saved_csr = 0;
+	} else
+		csr = p->dma_read(CSR, ch);
+	if (enable_1510_mode && ch <= 2 && (csr >> 7) != 0) {
+		dma_chan[ch + 6].saved_csr = csr >> 7;
+		csr &= 0x7f;
+	}
+	if ((csr & 0x3f) == 0)
+		return 0;
+	if (unlikely(dma_chan[ch].dev_id == -1)) {
+		pr_warn("Spurious interrupt from DMA channel %d (CSR %04x)\n",
+			ch, csr);
+		return 0;
+	}
+	if (unlikely(csr & OMAP1_DMA_TOUT_IRQ))
+		pr_warn("DMA timeout with device %d\n", dma_chan[ch].dev_id);
+	if (unlikely(csr & OMAP_DMA_DROP_IRQ))
+		pr_warn("DMA synchronization event drop occurred with device %d\n",
+			dma_chan[ch].dev_id);
+	if (likely(csr & OMAP_DMA_BLOCK_IRQ))
+		dma_chan[ch].flags &= ~OMAP_DMA_ACTIVE;
+	if (likely(dma_chan[ch].callback != NULL))
+		dma_chan[ch].callback(ch, csr, dma_chan[ch].data);
+
+	return 1;
+}
+
+static irqreturn_t omap1_dma_irq_handler(int irq, void *dev_id)
+{
+	int ch = ((int) dev_id) - 1;
+	int handled = 0;
+
+	for (;;) {
+		int handled_now = 0;
+
+		handled_now += omap1_dma_handle_ch(ch);
+		if (enable_1510_mode && dma_chan[ch + 6].saved_csr)
+			handled_now += omap1_dma_handle_ch(ch + 6);
+		if (!handled_now)
+			break;
+		handled += handled_now;
+	}
+
+	return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+struct omap_system_dma_plat_info *omap_get_plat_info(void)
+{
+	return p;
+}
+EXPORT_SYMBOL_GPL(omap_get_plat_info);
+
+static int omap_system_dma_probe(struct platform_device *pdev)
+{
+	int ch, ret = 0;
+	int dma_irq;
+	char irq_name[4];
+
+	p = pdev->dev.platform_data;
+	if (!p) {
+		dev_err(&pdev->dev,
+			"%s: System DMA initialized without platform data\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	d			= p->dma_attr;
+	errata			= p->errata;
+
+	if ((d->dev_caps & RESERVE_CHANNEL) && omap_dma_reserve_channels
+			&& (omap_dma_reserve_channels < d->lch_count))
+		d->lch_count	= omap_dma_reserve_channels;
+
+	dma_lch_count		= d->lch_count;
+	dma_chan_count		= dma_lch_count;
+	enable_1510_mode	= d->dev_caps & ENABLE_1510_MODE;
+
+	dma_chan = devm_kcalloc(&pdev->dev, dma_lch_count,
+				sizeof(*dma_chan), GFP_KERNEL);
+	if (!dma_chan)
+		return -ENOMEM;
+
+	for (ch = 0; ch < dma_chan_count; ch++) {
+		omap_clear_dma(ch);
+
+		dma_chan[ch].dev_id = -1;
+		dma_chan[ch].next_lch = -1;
+
+		if (ch >= 6 && enable_1510_mode)
+			continue;
+
+		/*
+		 * request_irq() doesn't like dev_id (ie. ch) being
+		 * zero, so we have to kludge around this.
+		 */
+		sprintf(&irq_name[0], "%d", ch);
+		dma_irq = platform_get_irq_byname(pdev, irq_name);
+
+		if (dma_irq < 0) {
+			ret = dma_irq;
+			goto exit_dma_irq_fail;
+		}
+
+		/* INT_DMA_LCD is handled in lcd_dma.c */
+		if (dma_irq == INT_DMA_LCD)
+			continue;
+
+		ret = request_irq(dma_irq,
+				omap1_dma_irq_handler, 0, "DMA",
+				(void *) (ch + 1));
+		if (ret != 0)
+			goto exit_dma_irq_fail;
+	}
+
+	/* reserve dma channels 0 and 1 in high security devices on 34xx */
+	if (d->dev_caps & HS_CHANNELS_RESERVED) {
+		pr_info("Reserving DMA channels 0 and 1 for HS ROM code\n");
+		dma_chan[0].dev_id = 0;
+		dma_chan[1].dev_id = 1;
+	}
+	p->show_dma_caps();
+	return 0;
+
+exit_dma_irq_fail:
+	return ret;
+}
+
+static void omap_system_dma_remove(struct platform_device *pdev)
+{
+	int dma_irq, irq_rel = 0;
+
+	for ( ; irq_rel < dma_chan_count; irq_rel++) {
+		dma_irq = platform_get_irq(pdev, irq_rel);
+		free_irq(dma_irq, (void *)(irq_rel + 1));
+	}
+}
+
+static struct platform_driver omap_system_dma_driver = {
+	.probe		= omap_system_dma_probe,
+	.remove_new	= omap_system_dma_remove,
+	.driver		= {
+		.name	= "omap_dma_system"
+	},
+};
+
+static int __init omap_system_dma_init(void)
+{
+	return platform_driver_register(&omap_system_dma_driver);
+}
+arch_initcall(omap_system_dma_init);
+
+static void __exit omap_system_dma_exit(void)
+{
+	platform_driver_unregister(&omap_system_dma_driver);
+}
+
+MODULE_DESCRIPTION("OMAP SYSTEM DMA DRIVER");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Texas Instruments Inc");
+
+/*
+ * Reserve the omap SDMA channels using cmdline bootarg
+ * "omap_dma_reserve_ch=". The valid range is 1 to 32
+ */
+static int __init omap_dma_cmdline_reserve_ch(char *str)
+{
+	if (get_option(&str, &omap_dma_reserve_channels) != 1)
+		omap_dma_reserve_channels = 0;
+	return 1;
+}
+
+__setup("omap_dma_reserve_ch=", omap_dma_cmdline_reserve_ch);
+
+