1 files changed, 943 insertions, 0 deletions

diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
new file mode 100644
index 000000000000..027c9be97654
--- /dev/null
+++ b/drivers/dma/sh/shdma.c
@@ -0,0 +1,943 @@
+/*
+ * Renesas SuperH DMA Engine support
+ *
+ * base is drivers/dma/flsdma.c
+ *
+ * Copyright (C) 2011-2012 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
+ * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
+ * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * This 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.
+ *
+ * - DMA of SuperH does not have Hardware DMA chain mode.
+ * - MAX DMA size is 16MB.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/sh_dma.h>
+#include <linux/notifier.h>
+#include <linux/kdebug.h>
+#include <linux/spinlock.h>
+#include <linux/rculist.h>
+
+#include "../dmaengine.h"
+#include "shdma.h"
+
+#define SH_DMAE_DRV_NAME "sh-dma-engine"
+
+/* Default MEMCPY transfer size = 2^2 = 4 bytes */
+#define LOG2_DEFAULT_XFER_SIZE	2
+#define SH_DMA_SLAVE_NUMBER 256
+#define SH_DMA_TCR_MAX (16 * 1024 * 1024 - 1)
+
+/*
+ * Used for write-side mutual exclusion for the global device list,
+ * read-side synchronization by way of RCU, and per-controller data.
+ */
+static DEFINE_SPINLOCK(sh_dmae_lock);
+static LIST_HEAD(sh_dmae_devices);
+
+static void chclr_write(struct sh_dmae_chan *sh_dc, u32 data)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	__raw_writel(data, shdev->chan_reg +
+		     shdev->pdata->channel[sh_dc->shdma_chan.id].chclr_offset);
+}
+
+static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
+{
+	__raw_writel(data, sh_dc->base + reg / sizeof(u32));
+}
+
+static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
+{
+	return __raw_readl(sh_dc->base + reg / sizeof(u32));
+}
+
+static u16 dmaor_read(struct sh_dmae_device *shdev)
+{
+	u32 __iomem *addr = shdev->chan_reg + DMAOR / sizeof(u32);
+
+	if (shdev->pdata->dmaor_is_32bit)
+		return __raw_readl(addr);
+	else
+		return __raw_readw(addr);
+}
+
+static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
+{
+	u32 __iomem *addr = shdev->chan_reg + DMAOR / sizeof(u32);
+
+	if (shdev->pdata->dmaor_is_32bit)
+		__raw_writel(data, addr);
+	else
+		__raw_writew(data, addr);
+}
+
+static void chcr_write(struct sh_dmae_chan *sh_dc, u32 data)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	__raw_writel(data, sh_dc->base + shdev->chcr_offset / sizeof(u32));
+}
+
+static u32 chcr_read(struct sh_dmae_chan *sh_dc)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	return __raw_readl(sh_dc->base + shdev->chcr_offset / sizeof(u32));
+}
+
+/*
+ * Reset DMA controller
+ *
+ * SH7780 has two DMAOR register
+ */
+static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
+{
+	unsigned short dmaor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sh_dmae_lock, flags);
+
+	dmaor = dmaor_read(shdev);
+	dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
+
+	spin_unlock_irqrestore(&sh_dmae_lock, flags);
+}
+
+static int sh_dmae_rst(struct sh_dmae_device *shdev)
+{
+	unsigned short dmaor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sh_dmae_lock, flags);
+
+	dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME);
+
+	if (shdev->pdata->chclr_present) {
+		int i;
+		for (i = 0; i < shdev->pdata->channel_num; i++) {
+			struct sh_dmae_chan *sh_chan = shdev->chan[i];
+			if (sh_chan)
+				chclr_write(sh_chan, 0);
+		}
+	}
+
+	dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init);
+
+	dmaor = dmaor_read(shdev);
+
+	spin_unlock_irqrestore(&sh_dmae_lock, flags);
+
+	if (dmaor & (DMAOR_AE | DMAOR_NMIF)) {
+		dev_warn(shdev->shdma_dev.dma_dev.dev, "Can't initialize DMAOR.\n");
+		return -EIO;
+	}
+	if (shdev->pdata->dmaor_init & ~dmaor)
+		dev_warn(shdev->shdma_dev.dma_dev.dev,
+			 "DMAOR=0x%x hasn't latched the initial value 0x%x.\n",
+			 dmaor, shdev->pdata->dmaor_init);
+	return 0;
+}
+
+static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
+{
+	u32 chcr = chcr_read(sh_chan);
+
+	if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
+		return true; /* working */
+
+	return false; /* waiting */
+}
+
+static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
+		((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
+
+	if (cnt >= pdata->ts_shift_num)
+		cnt = 0;
+
+	return pdata->ts_shift[cnt];
+}
+
+static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	int i;
+
+	for (i = 0; i < pdata->ts_shift_num; i++)
+		if (pdata->ts_shift[i] == l2size)
+			break;
+
+	if (i == pdata->ts_shift_num)
+		i = 0;
+
+	return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
+		((i << pdata->ts_high_shift) & pdata->ts_high_mask);
+}
+
+static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
+{
+	sh_dmae_writel(sh_chan, hw->sar, SAR);
+	sh_dmae_writel(sh_chan, hw->dar, DAR);
+	sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
+}
+
+static void dmae_start(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	u32 chcr = chcr_read(sh_chan);
+
+	if (shdev->pdata->needs_tend_set)
+		sh_dmae_writel(sh_chan, 0xFFFFFFFF, TEND);
+
+	chcr |= CHCR_DE | shdev->chcr_ie_bit;
+	chcr_write(sh_chan, chcr & ~CHCR_TE);
+}
+
+static void dmae_init(struct sh_dmae_chan *sh_chan)
+{
+	/*
+	 * Default configuration for dual address memory-memory transfer.
+	 * 0x400 represents auto-request.
+	 */
+	u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
+						   LOG2_DEFAULT_XFER_SIZE);
+	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
+	chcr_write(sh_chan, chcr);
+}
+
+static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
+{
+	/* If DMA is active, cannot set CHCR. TODO: remove this superfluous check */
+	if (dmae_is_busy(sh_chan))
+		return -EBUSY;
+
+	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
+	chcr_write(sh_chan, val);
+
+	return 0;
+}
+
+static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->shdma_chan.id];
+	u16 __iomem *addr = shdev->dmars;
+	unsigned int shift = chan_pdata->dmars_bit;
+
+	if (dmae_is_busy(sh_chan))
+		return -EBUSY;
+
+	if (pdata->no_dmars)
+		return 0;
+
+	/* in the case of a missing DMARS resource use first memory window */
+	if (!addr)
+		addr = (u16 __iomem *)shdev->chan_reg;
+	addr += chan_pdata->dmars / sizeof(u16);
+
+	__raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
+		     addr);
+
+	return 0;
+}
+
+static void sh_dmae_start_xfer(struct shdma_chan *schan,
+			       struct shdma_desc *sdesc)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+	struct sh_dmae_desc *sh_desc = container_of(sdesc,
+					struct sh_dmae_desc, shdma_desc);
+	dev_dbg(sh_chan->shdma_chan.dev, "Queue #%d to %d: %u@%x -> %x\n",
+		sdesc->async_tx.cookie, sh_chan->shdma_chan.id,
+		sh_desc->hw.tcr, sh_desc->hw.sar, sh_desc->hw.dar);
+	/* Get the ld start address from ld_queue */
+	dmae_set_reg(sh_chan, &sh_desc->hw);
+	dmae_start(sh_chan);
+}
+
+static bool sh_dmae_channel_busy(struct shdma_chan *schan)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+	return dmae_is_busy(sh_chan);
+}
+
+static void sh_dmae_setup_xfer(struct shdma_chan *schan,
+			       int slave_id)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+
+	if (slave_id >= 0) {
+		const struct sh_dmae_slave_config *cfg =
+			sh_chan->config;
+
+		dmae_set_dmars(sh_chan, cfg->mid_rid);
+		dmae_set_chcr(sh_chan, cfg->chcr);
+	} else {
+		dmae_init(sh_chan);
+	}
+}
+
+static const struct sh_dmae_slave_config *dmae_find_slave(
+	struct sh_dmae_chan *sh_chan, int slave_id)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	const struct sh_dmae_slave_config *cfg;
+	int i;
+
+	if (slave_id >= SH_DMA_SLAVE_NUMBER)
+		return NULL;
+
+	for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
+		if (cfg->slave_id == slave_id)
+			return cfg;
+
+	return NULL;
+}
+
+static int sh_dmae_set_slave(struct shdma_chan *schan,
+			     int slave_id, bool try)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+	const struct sh_dmae_slave_config *cfg = dmae_find_slave(sh_chan, slave_id);
+	if (!cfg)
+		return -ENODEV;
+
+	if (!try)
+		sh_chan->config = cfg;
+
+	return 0;
+}
+
+static void dmae_halt(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	u32 chcr = chcr_read(sh_chan);
+
+	chcr &= ~(CHCR_DE | CHCR_TE | shdev->chcr_ie_bit);
+	chcr_write(sh_chan, chcr);
+}
+
+static int sh_dmae_desc_setup(struct shdma_chan *schan,
+			      struct shdma_desc *sdesc,
+			      dma_addr_t src, dma_addr_t dst, size_t *len)
+{
+	struct sh_dmae_desc *sh_desc = container_of(sdesc,
+					struct sh_dmae_desc, shdma_desc);
+
+	if (*len > schan->max_xfer_len)
+		*len = schan->max_xfer_len;
+
+	sh_desc->hw.sar = src;
+	sh_desc->hw.dar = dst;
+	sh_desc->hw.tcr = *len;
+
+	return 0;
+}
+
+static void sh_dmae_halt(struct shdma_chan *schan)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+	dmae_halt(sh_chan);
+}
+
+static bool sh_dmae_chan_irq(struct shdma_chan *schan, int irq)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
+						    shdma_chan);
+
+	if (!(chcr_read(sh_chan) & CHCR_TE))
+		return false;
+
+	/* DMA stop */
+	dmae_halt(sh_chan);
+
+	return true;
+}
+
+/* Called from error IRQ or NMI */
+static bool sh_dmae_reset(struct sh_dmae_device *shdev)
+{
+	bool ret;
+
+	/* halt the dma controller */
+	sh_dmae_ctl_stop(shdev);
+
+	/* We cannot detect, which channel caused the error, have to reset all */
+	ret = shdma_reset(&shdev->shdma_dev);
+
+	sh_dmae_rst(shdev);
+
+	return ret;
+}
+
+static irqreturn_t sh_dmae_err(int irq, void *data)
+{
+	struct sh_dmae_device *shdev = data;
+
+	if (!(dmaor_read(shdev) & DMAOR_AE))
+		return IRQ_NONE;
+
+	sh_dmae_reset(shdev);
+	return IRQ_HANDLED;
+}
+
+static bool sh_dmae_desc_completed(struct shdma_chan *schan,
+				   struct shdma_desc *sdesc)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan,
+					struct sh_dmae_chan, shdma_chan);
+	struct sh_dmae_desc *sh_desc = container_of(sdesc,
+					struct sh_dmae_desc, shdma_desc);
+	u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
+	u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
+
+	return	(sdesc->direction == DMA_DEV_TO_MEM &&
+		 (sh_desc->hw.dar + sh_desc->hw.tcr) == dar_buf) ||
+		(sdesc->direction != DMA_DEV_TO_MEM &&
+		 (sh_desc->hw.sar + sh_desc->hw.tcr) == sar_buf);
+}
+
+static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
+{
+	/* Fast path out if NMIF is not asserted for this controller */
+	if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
+		return false;
+
+	return sh_dmae_reset(shdev);
+}
+
+static int sh_dmae_nmi_handler(struct notifier_block *self,
+			       unsigned long cmd, void *data)
+{
+	struct sh_dmae_device *shdev;
+	int ret = NOTIFY_DONE;
+	bool triggered;
+
+	/*
+	 * Only concern ourselves with NMI events.
+	 *
+	 * Normally we would check the die chain value, but as this needs
+	 * to be architecture independent, check for NMI context instead.
+	 */
+	if (!in_nmi())
+		return NOTIFY_DONE;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
+		/*
+		 * Only stop if one of the controllers has NMIF asserted,
+		 * we do not want to interfere with regular address error
+		 * handling or NMI events that don't concern the DMACs.
+		 */
+		triggered = sh_dmae_nmi_notify(shdev);
+		if (triggered == true)
+			ret = NOTIFY_OK;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
+	.notifier_call	= sh_dmae_nmi_handler,
+
+	/* Run before NMI debug handler and KGDB */
+	.priority	= 1,
+};
+
+static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
+					int irq, unsigned long flags)
+{
+	const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
+	struct shdma_dev *sdev = &shdev->shdma_dev;
+	struct platform_device *pdev = to_platform_device(sdev->dma_dev.dev);
+	struct sh_dmae_chan *sh_chan;
+	struct shdma_chan *schan;
+	int err;
+
+	sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
+	if (!sh_chan) {
+		dev_err(sdev->dma_dev.dev,
+			"No free memory for allocating dma channels!\n");
+		return -ENOMEM;
+	}
+
+	schan = &sh_chan->shdma_chan;
+	schan->max_xfer_len = SH_DMA_TCR_MAX + 1;
+
+	shdma_chan_probe(sdev, schan, id);
+
+	sh_chan->base = shdev->chan_reg + chan_pdata->offset / sizeof(u32);
+
+	/* set up channel irq */
+	if (pdev->id >= 0)
+		snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id),
+			 "sh-dmae%d.%d", pdev->id, id);
+	else
+		snprintf(sh_chan->dev_id, sizeof(sh_chan->dev_id),
+			 "sh-dma%d", id);
+
+	err = shdma_request_irq(schan, irq, flags, sh_chan->dev_id);
+	if (err) {
+		dev_err(sdev->dma_dev.dev,
+			"DMA channel %d request_irq error %d\n",
+			id, err);
+		goto err_no_irq;
+	}
+
+	shdev->chan[id] = sh_chan;
+	return 0;
+
+err_no_irq:
+	/* remove from dmaengine device node */
+	shdma_chan_remove(schan);
+	kfree(sh_chan);
+	return err;
+}
+
+static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
+{
+	struct dma_device *dma_dev = &shdev->shdma_dev.dma_dev;
+	struct shdma_chan *schan;
+	int i;
+
+	shdma_for_each_chan(schan, &shdev->shdma_dev, i) {
+		struct sh_dmae_chan *sh_chan = container_of(schan,
+					struct sh_dmae_chan, shdma_chan);
+		BUG_ON(!schan);
+
+		shdma_free_irq(&sh_chan->shdma_chan);
+
+		shdma_chan_remove(schan);
+		kfree(sh_chan);
+	}
+	dma_dev->chancnt = 0;
+}
+
+static void sh_dmae_shutdown(struct platform_device *pdev)
+{
+	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
+	sh_dmae_ctl_stop(shdev);
+}
+
+static int sh_dmae_runtime_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int sh_dmae_runtime_resume(struct device *dev)
+{
+	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+
+	return sh_dmae_rst(shdev);
+}
+
+#ifdef CONFIG_PM
+static int sh_dmae_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int sh_dmae_resume(struct device *dev)
+{
+	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+	int i, ret;
+
+	ret = sh_dmae_rst(shdev);
+	if (ret < 0)
+		dev_err(dev, "Failed to reset!\n");
+
+	for (i = 0; i < shdev->pdata->channel_num; i++) {
+		struct sh_dmae_chan *sh_chan = shdev->chan[i];
+
+		if (!sh_chan->shdma_chan.desc_num)
+			continue;
+
+		if (sh_chan->shdma_chan.slave_id >= 0) {
+			const struct sh_dmae_slave_config *cfg = sh_chan->config;
+			dmae_set_dmars(sh_chan, cfg->mid_rid);
+			dmae_set_chcr(sh_chan, cfg->chcr);
+		} else {
+			dmae_init(sh_chan);
+		}
+	}
+
+	return 0;
+}
+#else
+#define sh_dmae_suspend NULL
+#define sh_dmae_resume NULL
+#endif
+
+const struct dev_pm_ops sh_dmae_pm = {
+	.suspend		= sh_dmae_suspend,
+	.resume			= sh_dmae_resume,
+	.runtime_suspend	= sh_dmae_runtime_suspend,
+	.runtime_resume		= sh_dmae_runtime_resume,
+};
+
+static dma_addr_t sh_dmae_slave_addr(struct shdma_chan *schan)
+{
+	struct sh_dmae_chan *sh_chan = container_of(schan,
+					struct sh_dmae_chan, shdma_chan);
+
+	/*
+	 * Implicit BUG_ON(!sh_chan->config)
+	 * This is an exclusive slave DMA operation, may only be called after a
+	 * successful slave configuration.
+	 */
+	return sh_chan->config->addr;
+}
+
+static struct shdma_desc *sh_dmae_embedded_desc(void *buf, int i)
+{
+	return &((struct sh_dmae_desc *)buf)[i].shdma_desc;
+}
+
+static const struct shdma_ops sh_dmae_shdma_ops = {
+	.desc_completed = sh_dmae_desc_completed,
+	.halt_channel = sh_dmae_halt,
+	.channel_busy = sh_dmae_channel_busy,
+	.slave_addr = sh_dmae_slave_addr,
+	.desc_setup = sh_dmae_desc_setup,
+	.set_slave = sh_dmae_set_slave,
+	.setup_xfer = sh_dmae_setup_xfer,
+	.start_xfer = sh_dmae_start_xfer,
+	.embedded_desc = sh_dmae_embedded_desc,
+	.chan_irq = sh_dmae_chan_irq,
+};
+
+static int __devinit sh_dmae_probe(struct platform_device *pdev)
+{
+	struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
+	unsigned long irqflags = IRQF_DISABLED,
+		chan_flag[SH_DMAE_MAX_CHANNELS] = {};
+	int errirq, chan_irq[SH_DMAE_MAX_CHANNELS];
+	int err, i, irq_cnt = 0, irqres = 0, irq_cap = 0;
+	struct sh_dmae_device *shdev;
+	struct dma_device *dma_dev;
+	struct resource *chan, *dmars, *errirq_res, *chanirq_res;
+
+	/* get platform data */
+	if (!pdata || !pdata->channel_num)
+		return -ENODEV;
+
+	chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	/* DMARS area is optional */
+	dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	/*
+	 * IRQ resources:
+	 * 1. there always must be at least one IRQ IO-resource. On SH4 it is
+	 *    the error IRQ, in which case it is the only IRQ in this resource:
+	 *    start == end. If it is the only IRQ resource, all channels also
+	 *    use the same IRQ.
+	 * 2. DMA channel IRQ resources can be specified one per resource or in
+	 *    ranges (start != end)
+	 * 3. iff all events (channels and, optionally, error) on this
+	 *    controller use the same IRQ, only one IRQ resource can be
+	 *    specified, otherwise there must be one IRQ per channel, even if
+	 *    some of them are equal
+	 * 4. if all IRQs on this controller are equal or if some specific IRQs
+	 *    specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
+	 *    requested with the IRQF_SHARED flag
+	 */
+	errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!chan || !errirq_res)
+		return -ENODEV;
+
+	if (!request_mem_region(chan->start, resource_size(chan), pdev->name)) {
+		dev_err(&pdev->dev, "DMAC register region already claimed\n");
+		return -EBUSY;
+	}
+
+	if (dmars && !request_mem_region(dmars->start, resource_size(dmars), pdev->name)) {
+		dev_err(&pdev->dev, "DMAC DMARS region already claimed\n");
+		err = -EBUSY;
+		goto ermrdmars;
+	}
+
+	err = -ENOMEM;
+	shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
+	if (!shdev) {
+		dev_err(&pdev->dev, "Not enough memory\n");
+		goto ealloc;
+	}
+
+	dma_dev = &shdev->shdma_dev.dma_dev;
+
+	shdev->chan_reg = ioremap(chan->start, resource_size(chan));
+	if (!shdev->chan_reg)
+		goto emapchan;
+	if (dmars) {
+		shdev->dmars = ioremap(dmars->start, resource_size(dmars));
+		if (!shdev->dmars)
+			goto emapdmars;
+	}
+
+	if (!pdata->slave_only)
+		dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	if (pdata->slave && pdata->slave_num)
+		dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+
+	/* Default transfer size of 32 bytes requires 32-byte alignment */
+	dma_dev->copy_align = LOG2_DEFAULT_XFER_SIZE;
+
+	shdev->shdma_dev.ops = &sh_dmae_shdma_ops;
+	shdev->shdma_dev.desc_size = sizeof(struct sh_dmae_desc);
+	err = shdma_init(&pdev->dev, &shdev->shdma_dev,
+			      pdata->channel_num);
+	if (err < 0)
+		goto eshdma;
+
+	/* platform data */
+	shdev->pdata = pdev->dev.platform_data;
+
+	if (pdata->chcr_offset)
+		shdev->chcr_offset = pdata->chcr_offset;
+	else
+		shdev->chcr_offset = CHCR;
+
+	if (pdata->chcr_ie_bit)
+		shdev->chcr_ie_bit = pdata->chcr_ie_bit;
+	else
+		shdev->chcr_ie_bit = CHCR_IE;
+
+	platform_set_drvdata(pdev, shdev);
+
+	pm_runtime_enable(&pdev->dev);
+	err = pm_runtime_get_sync(&pdev->dev);
+	if (err < 0)
+		dev_err(&pdev->dev, "%s(): GET = %d\n", __func__, err);
+
+	spin_lock_irq(&sh_dmae_lock);
+	list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	/* reset dma controller - only needed as a test */
+	err = sh_dmae_rst(shdev);
+	if (err)
+		goto rst_err;
+
+#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
+	chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+	if (!chanirq_res)
+		chanirq_res = errirq_res;
+	else
+		irqres++;
+
+	if (chanirq_res == errirq_res ||
+	    (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
+		irqflags = IRQF_SHARED;
+
+	errirq = errirq_res->start;
+
+	err = request_irq(errirq, sh_dmae_err, irqflags,
+			  "DMAC Address Error", shdev);
+	if (err) {
+		dev_err(&pdev->dev,
+			"DMA failed requesting irq #%d, error %d\n",
+			errirq, err);
+		goto eirq_err;
+	}
+
+#else
+	chanirq_res = errirq_res;
+#endif /* CONFIG_CPU_SH4 || CONFIG_ARCH_SHMOBILE */
+
+	if (chanirq_res->start == chanirq_res->end &&
+	    !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
+		/* Special case - all multiplexed */
+		for (; irq_cnt < pdata->channel_num; irq_cnt++) {
+			if (irq_cnt < SH_DMAE_MAX_CHANNELS) {
+				chan_irq[irq_cnt] = chanirq_res->start;
+				chan_flag[irq_cnt] = IRQF_SHARED;
+			} else {
+				irq_cap = 1;
+				break;
+			}
+		}
+	} else {
+		do {
+			for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
+				if (irq_cnt >= SH_DMAE_MAX_CHANNELS) {
+					irq_cap = 1;
+					break;
+				}
+
+				if ((errirq_res->flags & IORESOURCE_BITS) ==
+				    IORESOURCE_IRQ_SHAREABLE)
+					chan_flag[irq_cnt] = IRQF_SHARED;
+				else
+					chan_flag[irq_cnt] = IRQF_DISABLED;
+				dev_dbg(&pdev->dev,
+					"Found IRQ %d for channel %d\n",
+					i, irq_cnt);
+				chan_irq[irq_cnt++] = i;
+			}
+
+			if (irq_cnt >= SH_DMAE_MAX_CHANNELS)
+				break;
+
+			chanirq_res = platform_get_resource(pdev,
+						IORESOURCE_IRQ, ++irqres);
+		} while (irq_cnt < pdata->channel_num && chanirq_res);
+	}
+
+	/* Create DMA Channel */
+	for (i = 0; i < irq_cnt; i++) {
+		err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
+		if (err)
+			goto chan_probe_err;
+	}
+
+	if (irq_cap)
+		dev_notice(&pdev->dev, "Attempting to register %d DMA "
+			   "channels when a maximum of %d are supported.\n",
+			   pdata->channel_num, SH_DMAE_MAX_CHANNELS);
+
+	pm_runtime_put(&pdev->dev);
+
+	err = dma_async_device_register(&shdev->shdma_dev.dma_dev);
+	if (err < 0)
+		goto edmadevreg;
+
+	return err;
+
+edmadevreg:
+	pm_runtime_get(&pdev->dev);
+
+chan_probe_err:
+	sh_dmae_chan_remove(shdev);
+
+#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
+	free_irq(errirq, shdev);
+eirq_err:
+#endif
+rst_err:
+	spin_lock_irq(&sh_dmae_lock);
+	list_del_rcu(&shdev->node);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	platform_set_drvdata(pdev, NULL);
+	shdma_cleanup(&shdev->shdma_dev);
+eshdma:
+	if (dmars)
+		iounmap(shdev->dmars);
+emapdmars:
+	iounmap(shdev->chan_reg);
+	synchronize_rcu();
+emapchan:
+	kfree(shdev);
+ealloc:
+	if (dmars)
+		release_mem_region(dmars->start, resource_size(dmars));
+ermrdmars:
+	release_mem_region(chan->start, resource_size(chan));
+
+	return err;
+}
+
+static int __devexit sh_dmae_remove(struct platform_device *pdev)
+{
+	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
+	struct dma_device *dma_dev = &shdev->shdma_dev.dma_dev;
+	struct resource *res;
+	int errirq = platform_get_irq(pdev, 0);
+
+	dma_async_device_unregister(dma_dev);
+
+	if (errirq > 0)
+		free_irq(errirq, shdev);
+
+	spin_lock_irq(&sh_dmae_lock);
+	list_del_rcu(&shdev->node);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	pm_runtime_disable(&pdev->dev);
+
+	sh_dmae_chan_remove(shdev);
+	shdma_cleanup(&shdev->shdma_dev);
+
+	if (shdev->dmars)
+		iounmap(shdev->dmars);
+	iounmap(shdev->chan_reg);
+
+	platform_set_drvdata(pdev, NULL);
+
+	synchronize_rcu();
+	kfree(shdev);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+
+	return 0;
+}
+
+static struct platform_driver sh_dmae_driver = {
+	.driver 	= {
+		.owner	= THIS_MODULE,
+		.pm	= &sh_dmae_pm,
+		.name	= SH_DMAE_DRV_NAME,
+	},
+	.remove		= __devexit_p(sh_dmae_remove),
+	.shutdown	= sh_dmae_shutdown,
+};
+
+static int __init sh_dmae_init(void)
+{
+	/* Wire up NMI handling */
+	int err = register_die_notifier(&sh_dmae_nmi_notifier);
+	if (err)
+		return err;
+
+	return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
+}
+module_init(sh_dmae_init);
+
+static void __exit sh_dmae_exit(void)
+{
+	platform_driver_unregister(&sh_dmae_driver);
+
+	unregister_die_notifier(&sh_dmae_nmi_notifier);
+}
+module_exit(sh_dmae_exit);
+
+MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
+MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" SH_DMAE_DRV_NAME);