Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 1030 insertions, 0 deletions

diff --git a/kernel/drivers/dma/pch_dma.c b/kernel/drivers/dma/pch_dma.c
new file mode 100644
index 000000000..b859792dd
--- /dev/null
+++ b/kernel/drivers/dma/pch_dma.c
@@ -0,0 +1,1030 @@
+/*
+ * Topcliff PCH DMA controller driver
+ * Copyright (c) 2010 Intel Corporation
+ * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
+ *
+ * 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.
+ *
+ * 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/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pch_dma.h>
+
+#include "dmaengine.h"
+
+#define DRV_NAME "pch-dma"
+
+#define DMA_CTL0_DISABLE		0x0
+#define DMA_CTL0_SG			0x1
+#define DMA_CTL0_ONESHOT		0x2
+#define DMA_CTL0_MODE_MASK_BITS		0x3
+#define DMA_CTL0_DIR_SHIFT_BITS		2
+#define DMA_CTL0_BITS_PER_CH		4
+
+#define DMA_CTL2_START_SHIFT_BITS	8
+#define DMA_CTL2_IRQ_ENABLE_MASK	((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
+
+#define DMA_STATUS_IDLE			0x0
+#define DMA_STATUS_DESC_READ		0x1
+#define DMA_STATUS_WAIT			0x2
+#define DMA_STATUS_ACCESS		0x3
+#define DMA_STATUS_BITS_PER_CH		2
+#define DMA_STATUS_MASK_BITS		0x3
+#define DMA_STATUS_SHIFT_BITS		16
+#define DMA_STATUS_IRQ(x)		(0x1 << (x))
+#define DMA_STATUS0_ERR(x)		(0x1 << ((x) + 8))
+#define DMA_STATUS2_ERR(x)		(0x1 << (x))
+
+#define DMA_DESC_WIDTH_SHIFT_BITS	12
+#define DMA_DESC_WIDTH_1_BYTE		(0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
+#define DMA_DESC_WIDTH_2_BYTES		(0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
+#define DMA_DESC_WIDTH_4_BYTES		(0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
+#define DMA_DESC_MAX_COUNT_1_BYTE	0x3FF
+#define DMA_DESC_MAX_COUNT_2_BYTES	0x3FF
+#define DMA_DESC_MAX_COUNT_4_BYTES	0x7FF
+#define DMA_DESC_END_WITHOUT_IRQ	0x0
+#define DMA_DESC_END_WITH_IRQ		0x1
+#define DMA_DESC_FOLLOW_WITHOUT_IRQ	0x2
+#define DMA_DESC_FOLLOW_WITH_IRQ	0x3
+
+#define MAX_CHAN_NR			12
+
+#define DMA_MASK_CTL0_MODE	0x33333333
+#define DMA_MASK_CTL2_MODE	0x00003333
+
+static unsigned int init_nr_desc_per_channel = 64;
+module_param(init_nr_desc_per_channel, uint, 0644);
+MODULE_PARM_DESC(init_nr_desc_per_channel,
+		 "initial descriptors per channel (default: 64)");
+
+struct pch_dma_desc_regs {
+	u32	dev_addr;
+	u32	mem_addr;
+	u32	size;
+	u32	next;
+};
+
+struct pch_dma_regs {
+	u32	dma_ctl0;
+	u32	dma_ctl1;
+	u32	dma_ctl2;
+	u32	dma_ctl3;
+	u32	dma_sts0;
+	u32	dma_sts1;
+	u32	dma_sts2;
+	u32	reserved3;
+	struct pch_dma_desc_regs desc[MAX_CHAN_NR];
+};
+
+struct pch_dma_desc {
+	struct pch_dma_desc_regs regs;
+	struct dma_async_tx_descriptor txd;
+	struct list_head	desc_node;
+	struct list_head	tx_list;
+};
+
+struct pch_dma_chan {
+	struct dma_chan		chan;
+	void __iomem *membase;
+	enum dma_transfer_direction dir;
+	struct tasklet_struct	tasklet;
+	unsigned long		err_status;
+
+	spinlock_t		lock;
+
+	struct list_head	active_list;
+	struct list_head	queue;
+	struct list_head	free_list;
+	unsigned int		descs_allocated;
+};
+
+#define PDC_DEV_ADDR	0x00
+#define PDC_MEM_ADDR	0x04
+#define PDC_SIZE	0x08
+#define PDC_NEXT	0x0C
+
+#define channel_readl(pdc, name) \
+	readl((pdc)->membase + PDC_##name)
+#define channel_writel(pdc, name, val) \
+	writel((val), (pdc)->membase + PDC_##name)
+
+struct pch_dma {
+	struct dma_device	dma;
+	void __iomem *membase;
+	struct pci_pool		*pool;
+	struct pch_dma_regs	regs;
+	struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
+	struct pch_dma_chan	channels[MAX_CHAN_NR];
+};
+
+#define PCH_DMA_CTL0	0x00
+#define PCH_DMA_CTL1	0x04
+#define PCH_DMA_CTL2	0x08
+#define PCH_DMA_CTL3	0x0C
+#define PCH_DMA_STS0	0x10
+#define PCH_DMA_STS1	0x14
+#define PCH_DMA_STS2	0x18
+
+#define dma_readl(pd, name) \
+	readl((pd)->membase + PCH_DMA_##name)
+#define dma_writel(pd, name, val) \
+	writel((val), (pd)->membase + PCH_DMA_##name)
+
+static inline
+struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
+{
+	return container_of(txd, struct pch_dma_desc, txd);
+}
+
+static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct pch_dma_chan, chan);
+}
+
+static inline struct pch_dma *to_pd(struct dma_device *ddev)
+{
+	return container_of(ddev, struct pch_dma, dma);
+}
+
+static inline struct device *chan2dev(struct dma_chan *chan)
+{
+	return &chan->dev->device;
+}
+
+static inline struct device *chan2parent(struct dma_chan *chan)
+{
+	return chan->dev->device.parent;
+}
+
+static inline
+struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
+{
+	return list_first_entry(&pd_chan->active_list,
+				struct pch_dma_desc, desc_node);
+}
+
+static inline
+struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
+{
+	return list_first_entry(&pd_chan->queue,
+				struct pch_dma_desc, desc_node);
+}
+
+static void pdc_enable_irq(struct dma_chan *chan, int enable)
+{
+	struct pch_dma *pd = to_pd(chan->device);
+	u32 val;
+	int pos;
+
+	if (chan->chan_id < 8)
+		pos = chan->chan_id;
+	else
+		pos = chan->chan_id + 8;
+
+	val = dma_readl(pd, CTL2);
+
+	if (enable)
+		val |= 0x1 << pos;
+	else
+		val &= ~(0x1 << pos);
+
+	dma_writel(pd, CTL2, val);
+
+	dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
+		chan->chan_id, val);
+}
+
+static void pdc_set_dir(struct dma_chan *chan)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+	struct pch_dma *pd = to_pd(chan->device);
+	u32 val;
+	u32 mask_mode;
+	u32 mask_ctl;
+
+	if (chan->chan_id < 8) {
+		val = dma_readl(pd, CTL0);
+
+		mask_mode = DMA_CTL0_MODE_MASK_BITS <<
+					(DMA_CTL0_BITS_PER_CH * chan->chan_id);
+		mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
+				       (DMA_CTL0_BITS_PER_CH * chan->chan_id));
+		val &= mask_mode;
+		if (pd_chan->dir == DMA_MEM_TO_DEV)
+			val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
+				       DMA_CTL0_DIR_SHIFT_BITS);
+		else
+			val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
+					 DMA_CTL0_DIR_SHIFT_BITS));
+
+		val |= mask_ctl;
+		dma_writel(pd, CTL0, val);
+	} else {
+		int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
+		val = dma_readl(pd, CTL3);
+
+		mask_mode = DMA_CTL0_MODE_MASK_BITS <<
+						(DMA_CTL0_BITS_PER_CH * ch);
+		mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
+						 (DMA_CTL0_BITS_PER_CH * ch));
+		val &= mask_mode;
+		if (pd_chan->dir == DMA_MEM_TO_DEV)
+			val |= 0x1 << (DMA_CTL0_BITS_PER_CH * ch +
+				       DMA_CTL0_DIR_SHIFT_BITS);
+		else
+			val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * ch +
+					 DMA_CTL0_DIR_SHIFT_BITS));
+		val |= mask_ctl;
+		dma_writel(pd, CTL3, val);
+	}
+
+	dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
+		chan->chan_id, val);
+}
+
+static void pdc_set_mode(struct dma_chan *chan, u32 mode)
+{
+	struct pch_dma *pd = to_pd(chan->device);
+	u32 val;
+	u32 mask_ctl;
+	u32 mask_dir;
+
+	if (chan->chan_id < 8) {
+		mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
+			   (DMA_CTL0_BITS_PER_CH * chan->chan_id));
+		mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +\
+				 DMA_CTL0_DIR_SHIFT_BITS);
+		val = dma_readl(pd, CTL0);
+		val &= mask_dir;
+		val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
+		val |= mask_ctl;
+		dma_writel(pd, CTL0, val);
+	} else {
+		int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
+		mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
+						 (DMA_CTL0_BITS_PER_CH * ch));
+		mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * ch +\
+				 DMA_CTL0_DIR_SHIFT_BITS);
+		val = dma_readl(pd, CTL3);
+		val &= mask_dir;
+		val |= mode << (DMA_CTL0_BITS_PER_CH * ch);
+		val |= mask_ctl;
+		dma_writel(pd, CTL3, val);
+	}
+
+	dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
+		chan->chan_id, val);
+}
+
+static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
+{
+	struct pch_dma *pd = to_pd(pd_chan->chan.device);
+	u32 val;
+
+	val = dma_readl(pd, STS0);
+	return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
+			DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
+}
+
+static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
+{
+	struct pch_dma *pd = to_pd(pd_chan->chan.device);
+	u32 val;
+
+	val = dma_readl(pd, STS2);
+	return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
+			DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
+}
+
+static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
+{
+	u32 sts;
+
+	if (pd_chan->chan.chan_id < 8)
+		sts = pdc_get_status0(pd_chan);
+	else
+		sts = pdc_get_status2(pd_chan);
+
+
+	if (sts == DMA_STATUS_IDLE)
+		return true;
+	else
+		return false;
+}
+
+static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
+{
+	if (!pdc_is_idle(pd_chan)) {
+		dev_err(chan2dev(&pd_chan->chan),
+			"BUG: Attempt to start non-idle channel\n");
+		return;
+	}
+
+	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
+		pd_chan->chan.chan_id, desc->regs.dev_addr);
+	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
+		pd_chan->chan.chan_id, desc->regs.mem_addr);
+	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
+		pd_chan->chan.chan_id, desc->regs.size);
+	dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
+		pd_chan->chan.chan_id, desc->regs.next);
+
+	if (list_empty(&desc->tx_list)) {
+		channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
+		channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
+		channel_writel(pd_chan, SIZE, desc->regs.size);
+		channel_writel(pd_chan, NEXT, desc->regs.next);
+		pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT);
+	} else {
+		channel_writel(pd_chan, NEXT, desc->txd.phys);
+		pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG);
+	}
+}
+
+static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
+			       struct pch_dma_desc *desc)
+{
+	struct dma_async_tx_descriptor *txd = &desc->txd;
+	dma_async_tx_callback callback = txd->callback;
+	void *param = txd->callback_param;
+
+	list_splice_init(&desc->tx_list, &pd_chan->free_list);
+	list_move(&desc->desc_node, &pd_chan->free_list);
+
+	if (callback)
+		callback(param);
+}
+
+static void pdc_complete_all(struct pch_dma_chan *pd_chan)
+{
+	struct pch_dma_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	BUG_ON(!pdc_is_idle(pd_chan));
+
+	if (!list_empty(&pd_chan->queue))
+		pdc_dostart(pd_chan, pdc_first_queued(pd_chan));
+
+	list_splice_init(&pd_chan->active_list, &list);
+	list_splice_init(&pd_chan->queue, &pd_chan->active_list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		pdc_chain_complete(pd_chan, desc);
+}
+
+static void pdc_handle_error(struct pch_dma_chan *pd_chan)
+{
+	struct pch_dma_desc *bad_desc;
+
+	bad_desc = pdc_first_active(pd_chan);
+	list_del(&bad_desc->desc_node);
+
+	list_splice_init(&pd_chan->queue, pd_chan->active_list.prev);
+
+	if (!list_empty(&pd_chan->active_list))
+		pdc_dostart(pd_chan, pdc_first_active(pd_chan));
+
+	dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
+	dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
+		 bad_desc->txd.cookie);
+
+	pdc_chain_complete(pd_chan, bad_desc);
+}
+
+static void pdc_advance_work(struct pch_dma_chan *pd_chan)
+{
+	if (list_empty(&pd_chan->active_list) ||
+		list_is_singular(&pd_chan->active_list)) {
+		pdc_complete_all(pd_chan);
+	} else {
+		pdc_chain_complete(pd_chan, pdc_first_active(pd_chan));
+		pdc_dostart(pd_chan, pdc_first_active(pd_chan));
+	}
+}
+
+static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
+{
+	struct pch_dma_desc *desc = to_pd_desc(txd);
+	struct pch_dma_chan *pd_chan = to_pd_chan(txd->chan);
+	dma_cookie_t cookie;
+
+	spin_lock(&pd_chan->lock);
+	cookie = dma_cookie_assign(txd);
+
+	if (list_empty(&pd_chan->active_list)) {
+		list_add_tail(&desc->desc_node, &pd_chan->active_list);
+		pdc_dostart(pd_chan, desc);
+	} else {
+		list_add_tail(&desc->desc_node, &pd_chan->queue);
+	}
+
+	spin_unlock(&pd_chan->lock);
+	return 0;
+}
+
+static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
+{
+	struct pch_dma_desc *desc = NULL;
+	struct pch_dma *pd = to_pd(chan->device);
+	dma_addr_t addr;
+
+	desc = pci_pool_alloc(pd->pool, flags, &addr);
+	if (desc) {
+		memset(desc, 0, sizeof(struct pch_dma_desc));
+		INIT_LIST_HEAD(&desc->tx_list);
+		dma_async_tx_descriptor_init(&desc->txd, chan);
+		desc->txd.tx_submit = pd_tx_submit;
+		desc->txd.flags = DMA_CTRL_ACK;
+		desc->txd.phys = addr;
+	}
+
+	return desc;
+}
+
+static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
+{
+	struct pch_dma_desc *desc, *_d;
+	struct pch_dma_desc *ret = NULL;
+	int i = 0;
+
+	spin_lock(&pd_chan->lock);
+	list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
+		i++;
+		if (async_tx_test_ack(&desc->txd)) {
+			list_del(&desc->desc_node);
+			ret = desc;
+			break;
+		}
+		dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
+	}
+	spin_unlock(&pd_chan->lock);
+	dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
+
+	if (!ret) {
+		ret = pdc_alloc_desc(&pd_chan->chan, GFP_ATOMIC);
+		if (ret) {
+			spin_lock(&pd_chan->lock);
+			pd_chan->descs_allocated++;
+			spin_unlock(&pd_chan->lock);
+		} else {
+			dev_err(chan2dev(&pd_chan->chan),
+				"failed to alloc desc\n");
+		}
+	}
+
+	return ret;
+}
+
+static void pdc_desc_put(struct pch_dma_chan *pd_chan,
+			 struct pch_dma_desc *desc)
+{
+	if (desc) {
+		spin_lock(&pd_chan->lock);
+		list_splice_init(&desc->tx_list, &pd_chan->free_list);
+		list_add(&desc->desc_node, &pd_chan->free_list);
+		spin_unlock(&pd_chan->lock);
+	}
+}
+
+static int pd_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+	struct pch_dma_desc *desc;
+	LIST_HEAD(tmp_list);
+	int i;
+
+	if (!pdc_is_idle(pd_chan)) {
+		dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
+		return -EIO;
+	}
+
+	if (!list_empty(&pd_chan->free_list))
+		return pd_chan->descs_allocated;
+
+	for (i = 0; i < init_nr_desc_per_channel; i++) {
+		desc = pdc_alloc_desc(chan, GFP_KERNEL);
+
+		if (!desc) {
+			dev_warn(chan2dev(chan),
+				"Only allocated %d initial descriptors\n", i);
+			break;
+		}
+
+		list_add_tail(&desc->desc_node, &tmp_list);
+	}
+
+	spin_lock_irq(&pd_chan->lock);
+	list_splice(&tmp_list, &pd_chan->free_list);
+	pd_chan->descs_allocated = i;
+	dma_cookie_init(chan);
+	spin_unlock_irq(&pd_chan->lock);
+
+	pdc_enable_irq(chan, 1);
+
+	return pd_chan->descs_allocated;
+}
+
+static void pd_free_chan_resources(struct dma_chan *chan)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+	struct pch_dma *pd = to_pd(chan->device);
+	struct pch_dma_desc *desc, *_d;
+	LIST_HEAD(tmp_list);
+
+	BUG_ON(!pdc_is_idle(pd_chan));
+	BUG_ON(!list_empty(&pd_chan->active_list));
+	BUG_ON(!list_empty(&pd_chan->queue));
+
+	spin_lock_irq(&pd_chan->lock);
+	list_splice_init(&pd_chan->free_list, &tmp_list);
+	pd_chan->descs_allocated = 0;
+	spin_unlock_irq(&pd_chan->lock);
+
+	list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
+		pci_pool_free(pd->pool, desc, desc->txd.phys);
+
+	pdc_enable_irq(chan, 0);
+}
+
+static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+				    struct dma_tx_state *txstate)
+{
+	return dma_cookie_status(chan, cookie, txstate);
+}
+
+static void pd_issue_pending(struct dma_chan *chan)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+
+	if (pdc_is_idle(pd_chan)) {
+		spin_lock(&pd_chan->lock);
+		pdc_advance_work(pd_chan);
+		spin_unlock(&pd_chan->lock);
+	}
+}
+
+static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
+			struct scatterlist *sgl, unsigned int sg_len,
+			enum dma_transfer_direction direction, unsigned long flags,
+			void *context)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+	struct pch_dma_slave *pd_slave = chan->private;
+	struct pch_dma_desc *first = NULL;
+	struct pch_dma_desc *prev = NULL;
+	struct pch_dma_desc *desc = NULL;
+	struct scatterlist *sg;
+	dma_addr_t reg;
+	int i;
+
+	if (unlikely(!sg_len)) {
+		dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
+		return NULL;
+	}
+
+	if (direction == DMA_DEV_TO_MEM)
+		reg = pd_slave->rx_reg;
+	else if (direction == DMA_MEM_TO_DEV)
+		reg = pd_slave->tx_reg;
+	else
+		return NULL;
+
+	pd_chan->dir = direction;
+	pdc_set_dir(chan);
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		desc = pdc_desc_get(pd_chan);
+
+		if (!desc)
+			goto err_desc_get;
+
+		desc->regs.dev_addr = reg;
+		desc->regs.mem_addr = sg_dma_address(sg);
+		desc->regs.size = sg_dma_len(sg);
+		desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
+
+		switch (pd_slave->width) {
+		case PCH_DMA_WIDTH_1_BYTE:
+			if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
+				goto err_desc_get;
+			desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
+			break;
+		case PCH_DMA_WIDTH_2_BYTES:
+			if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
+				goto err_desc_get;
+			desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
+			break;
+		case PCH_DMA_WIDTH_4_BYTES:
+			if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
+				goto err_desc_get;
+			desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
+			break;
+		default:
+			goto err_desc_get;
+		}
+
+		if (!first) {
+			first = desc;
+		} else {
+			prev->regs.next |= desc->txd.phys;
+			list_add_tail(&desc->desc_node, &first->tx_list);
+		}
+
+		prev = desc;
+	}
+
+	if (flags & DMA_PREP_INTERRUPT)
+		desc->regs.next = DMA_DESC_END_WITH_IRQ;
+	else
+		desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
+
+	first->txd.cookie = -EBUSY;
+	desc->txd.flags = flags;
+
+	return &first->txd;
+
+err_desc_get:
+	dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
+	pdc_desc_put(pd_chan, first);
+	return NULL;
+}
+
+static int pd_device_terminate_all(struct dma_chan *chan)
+{
+	struct pch_dma_chan *pd_chan = to_pd_chan(chan);
+	struct pch_dma_desc *desc, *_d;
+	LIST_HEAD(list);
+
+	spin_lock_irq(&pd_chan->lock);
+
+	pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
+
+	list_splice_init(&pd_chan->active_list, &list);
+	list_splice_init(&pd_chan->queue, &list);
+
+	list_for_each_entry_safe(desc, _d, &list, desc_node)
+		pdc_chain_complete(pd_chan, desc);
+
+	spin_unlock_irq(&pd_chan->lock);
+
+	return 0;
+}
+
+static void pdc_tasklet(unsigned long data)
+{
+	struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
+	unsigned long flags;
+
+	if (!pdc_is_idle(pd_chan)) {
+		dev_err(chan2dev(&pd_chan->chan),
+			"BUG: handle non-idle channel in tasklet\n");
+		return;
+	}
+
+	spin_lock_irqsave(&pd_chan->lock, flags);
+	if (test_and_clear_bit(0, &pd_chan->err_status))
+		pdc_handle_error(pd_chan);
+	else
+		pdc_advance_work(pd_chan);
+	spin_unlock_irqrestore(&pd_chan->lock, flags);
+}
+
+static irqreturn_t pd_irq(int irq, void *devid)
+{
+	struct pch_dma *pd = (struct pch_dma *)devid;
+	struct pch_dma_chan *pd_chan;
+	u32 sts0;
+	u32 sts2;
+	int i;
+	int ret0 = IRQ_NONE;
+	int ret2 = IRQ_NONE;
+
+	sts0 = dma_readl(pd, STS0);
+	sts2 = dma_readl(pd, STS2);
+
+	dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
+
+	for (i = 0; i < pd->dma.chancnt; i++) {
+		pd_chan = &pd->channels[i];
+
+		if (i < 8) {
+			if (sts0 & DMA_STATUS_IRQ(i)) {
+				if (sts0 & DMA_STATUS0_ERR(i))
+					set_bit(0, &pd_chan->err_status);
+
+				tasklet_schedule(&pd_chan->tasklet);
+				ret0 = IRQ_HANDLED;
+			}
+		} else {
+			if (sts2 & DMA_STATUS_IRQ(i - 8)) {
+				if (sts2 & DMA_STATUS2_ERR(i))
+					set_bit(0, &pd_chan->err_status);
+
+				tasklet_schedule(&pd_chan->tasklet);
+				ret2 = IRQ_HANDLED;
+			}
+		}
+	}
+
+	/* clear interrupt bits in status register */
+	if (ret0)
+		dma_writel(pd, STS0, sts0);
+	if (ret2)
+		dma_writel(pd, STS2, sts2);
+
+	return ret0 | ret2;
+}
+
+#ifdef	CONFIG_PM
+static void pch_dma_save_regs(struct pch_dma *pd)
+{
+	struct pch_dma_chan *pd_chan;
+	struct dma_chan *chan, *_c;
+	int i = 0;
+
+	pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
+	pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
+	pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
+	pd->regs.dma_ctl3 = dma_readl(pd, CTL3);
+
+	list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
+		pd_chan = to_pd_chan(chan);
+
+		pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
+		pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
+		pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
+		pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
+
+		i++;
+	}
+}
+
+static void pch_dma_restore_regs(struct pch_dma *pd)
+{
+	struct pch_dma_chan *pd_chan;
+	struct dma_chan *chan, *_c;
+	int i = 0;
+
+	dma_writel(pd, CTL0, pd->regs.dma_ctl0);
+	dma_writel(pd, CTL1, pd->regs.dma_ctl1);
+	dma_writel(pd, CTL2, pd->regs.dma_ctl2);
+	dma_writel(pd, CTL3, pd->regs.dma_ctl3);
+
+	list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
+		pd_chan = to_pd_chan(chan);
+
+		channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
+		channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
+		channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
+		channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
+
+		i++;
+	}
+}
+
+static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	struct pch_dma *pd = pci_get_drvdata(pdev);
+
+	if (pd)
+		pch_dma_save_regs(pd);
+
+	pci_save_state(pdev);
+	pci_disable_device(pdev);
+	pci_set_power_state(pdev, pci_choose_state(pdev, state));
+
+	return 0;
+}
+
+static int pch_dma_resume(struct pci_dev *pdev)
+{
+	struct pch_dma *pd = pci_get_drvdata(pdev);
+	int err;
+
+	pci_set_power_state(pdev, PCI_D0);
+	pci_restore_state(pdev);
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_dbg(&pdev->dev, "failed to enable device\n");
+		return err;
+	}
+
+	if (pd)
+		pch_dma_restore_regs(pd);
+
+	return 0;
+}
+#endif
+
+static int pch_dma_probe(struct pci_dev *pdev,
+				   const struct pci_device_id *id)
+{
+	struct pch_dma *pd;
+	struct pch_dma_regs *regs;
+	unsigned int nr_channels;
+	int err;
+	int i;
+
+	nr_channels = id->driver_data;
+	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pci_set_drvdata(pdev, pd);
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot enable PCI device\n");
+		goto err_free_mem;
+	}
+
+	if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
+		dev_err(&pdev->dev, "Cannot find proper base address\n");
+		err = -ENODEV;
+		goto err_disable_pdev;
+	}
+
+	err = pci_request_regions(pdev, DRV_NAME);
+	if (err) {
+		dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
+		goto err_disable_pdev;
+	}
+
+	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+	if (err) {
+		dev_err(&pdev->dev, "Cannot set proper DMA config\n");
+		goto err_free_res;
+	}
+
+	regs = pd->membase = pci_iomap(pdev, 1, 0);
+	if (!pd->membase) {
+		dev_err(&pdev->dev, "Cannot map MMIO registers\n");
+		err = -ENOMEM;
+		goto err_free_res;
+	}
+
+	pci_set_master(pdev);
+
+	err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to request IRQ\n");
+		goto err_iounmap;
+	}
+
+	pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
+				   sizeof(struct pch_dma_desc), 4, 0);
+	if (!pd->pool) {
+		dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
+		err = -ENOMEM;
+		goto err_free_irq;
+	}
+
+	pd->dma.dev = &pdev->dev;
+
+	INIT_LIST_HEAD(&pd->dma.channels);
+
+	for (i = 0; i < nr_channels; i++) {
+		struct pch_dma_chan *pd_chan = &pd->channels[i];
+
+		pd_chan->chan.device = &pd->dma;
+		dma_cookie_init(&pd_chan->chan);
+
+		pd_chan->membase = &regs->desc[i];
+
+		spin_lock_init(&pd_chan->lock);
+
+		INIT_LIST_HEAD(&pd_chan->active_list);
+		INIT_LIST_HEAD(&pd_chan->queue);
+		INIT_LIST_HEAD(&pd_chan->free_list);
+
+		tasklet_init(&pd_chan->tasklet, pdc_tasklet,
+			     (unsigned long)pd_chan);
+		list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
+	}
+
+	dma_cap_zero(pd->dma.cap_mask);
+	dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
+	dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
+
+	pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
+	pd->dma.device_free_chan_resources = pd_free_chan_resources;
+	pd->dma.device_tx_status = pd_tx_status;
+	pd->dma.device_issue_pending = pd_issue_pending;
+	pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
+	pd->dma.device_terminate_all = pd_device_terminate_all;
+
+	err = dma_async_device_register(&pd->dma);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to register DMA device\n");
+		goto err_free_pool;
+	}
+
+	return 0;
+
+err_free_pool:
+	pci_pool_destroy(pd->pool);
+err_free_irq:
+	free_irq(pdev->irq, pd);
+err_iounmap:
+	pci_iounmap(pdev, pd->membase);
+err_free_res:
+	pci_release_regions(pdev);
+err_disable_pdev:
+	pci_disable_device(pdev);
+err_free_mem:
+	kfree(pd);
+	return err;
+}
+
+static void pch_dma_remove(struct pci_dev *pdev)
+{
+	struct pch_dma *pd = pci_get_drvdata(pdev);
+	struct pch_dma_chan *pd_chan;
+	struct dma_chan *chan, *_c;
+
+	if (pd) {
+		dma_async_device_unregister(&pd->dma);
+
+		free_irq(pdev->irq, pd);
+
+		list_for_each_entry_safe(chan, _c, &pd->dma.channels,
+					 device_node) {
+			pd_chan = to_pd_chan(chan);
+
+			tasklet_kill(&pd_chan->tasklet);
+		}
+
+		pci_pool_destroy(pd->pool);
+		pci_iounmap(pdev, pd->membase);
+		pci_release_regions(pdev);
+		pci_disable_device(pdev);
+		kfree(pd);
+	}
+}
+
+/* PCI Device ID of DMA device */
+#define PCI_VENDOR_ID_ROHM             0x10DB
+#define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
+#define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
+#define PCI_DEVICE_ID_ML7213_DMA1_8CH	0x8026
+#define PCI_DEVICE_ID_ML7213_DMA2_8CH	0x802B
+#define PCI_DEVICE_ID_ML7213_DMA3_4CH	0x8034
+#define PCI_DEVICE_ID_ML7213_DMA4_12CH	0x8032
+#define PCI_DEVICE_ID_ML7223_DMA1_4CH	0x800B
+#define PCI_DEVICE_ID_ML7223_DMA2_4CH	0x800E
+#define PCI_DEVICE_ID_ML7223_DMA3_4CH	0x8017
+#define PCI_DEVICE_ID_ML7223_DMA4_4CH	0x803B
+#define PCI_DEVICE_ID_ML7831_DMA1_8CH	0x8810
+#define PCI_DEVICE_ID_ML7831_DMA2_4CH	0x8815
+
+static const struct pci_device_id pch_dma_id_table[] = {
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA4_12CH), 12}, /* I2S */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA1_4CH), 4}, /* UART */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA2_4CH), 4}, /* Video SPI */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA3_4CH), 4}, /* Security */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA4_4CH), 4}, /* FPGA */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA1_8CH), 8}, /* UART */
+	{ PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA2_4CH), 4}, /* SPI */
+	{ 0, },
+};
+
+static struct pci_driver pch_dma_driver = {
+	.name		= DRV_NAME,
+	.id_table	= pch_dma_id_table,
+	.probe		= pch_dma_probe,
+	.remove		= pch_dma_remove,
+#ifdef CONFIG_PM
+	.suspend	= pch_dma_suspend,
+	.resume		= pch_dma_resume,
+#endif
+};
+
+module_pci_driver(pch_dma_driver);
+
+MODULE_DESCRIPTION("Intel EG20T PCH / LAPIS Semicon ML7213/ML7223/ML7831 IOH "
+		   "DMA controller driver");
+MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(pci, pch_dma_id_table);