/*
   * Copyright (c) 2013 Linaro Ltd.
   * Copyright (c) 2013 Hisilicon Limited.
   *
   * 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.
   */
  #include <linux/sched.h>
  #include <linux/device.h>
  #include <linux/dmaengine.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include <linux/of_device.h>
  #include <linux/of.h>
  #include <linux/clk.h>
  #include <linux/of_dma.h>
  
  #include "virt-dma.h"
  
  #define DRIVER_NAME		"k3-dma"
  #define DMA_ALIGN		3
  #define DMA_MAX_SIZE		0x1ffc
  
  #define INT_STAT		0x00
  #define INT_TC1			0x04
  #define INT_ERR1		0x0c
  #define INT_ERR2		0x10
  #define INT_TC1_MASK		0x18
  #define INT_ERR1_MASK		0x20
  #define INT_ERR2_MASK		0x24
  #define INT_TC1_RAW		0x600
  #define INT_ERR1_RAW		0x608
  #define INT_ERR2_RAW		0x610
  #define CH_PRI			0x688
  #define CH_STAT			0x690
  #define CX_CUR_CNT		0x704
  #define CX_LLI			0x800
  #define CX_CNT			0x810
  #define CX_SRC			0x814
  #define CX_DST			0x818
  #define CX_CFG			0x81c
  #define AXI_CFG			0x820
  #define AXI_CFG_DEFAULT		0x201201
  
  #define CX_LLI_CHAIN_EN		0x2
  #define CX_CFG_EN		0x1
  #define CX_CFG_MEM2PER		(0x1 << 2)
  #define CX_CFG_PER2MEM		(0x2 << 2)
  #define CX_CFG_SRCINCR		(0x1 << 31)
  #define CX_CFG_DSTINCR		(0x1 << 30)
  
  struct k3_desc_hw {
  	u32 lli;
  	u32 reserved[3];
  	u32 count;
  	u32 saddr;
  	u32 daddr;
  	u32 config;
  } __aligned(32);
  
  struct k3_dma_desc_sw {
  	struct virt_dma_desc	vd;
  	dma_addr_t		desc_hw_lli;
  	size_t			desc_num;
  	size_t			size;
  	struct k3_desc_hw	desc_hw[0];
  };
  
  struct k3_dma_phy;
  
  struct k3_dma_chan {
  	u32			ccfg;
  	struct virt_dma_chan	vc;
  	struct k3_dma_phy	*phy;
  	struct list_head	node;
  	enum dma_transfer_direction dir;
  	dma_addr_t		dev_addr;
  	enum dma_status		status;
  };
  
  struct k3_dma_phy {
  	u32			idx;
  	void __iomem		*base;
  	struct k3_dma_chan	*vchan;
  	struct k3_dma_desc_sw	*ds_run;
  	struct k3_dma_desc_sw	*ds_done;
  };
  
  struct k3_dma_dev {
  	struct dma_device	slave;
  	void __iomem		*base;
  	struct tasklet_struct	task;
  	spinlock_t		lock;
  	struct list_head	chan_pending;
  	struct k3_dma_phy	*phy;
  	struct k3_dma_chan	*chans;
  	struct clk		*clk;
  	u32			dma_channels;
  	u32			dma_requests;
  };
  
  #define to_k3_dma(dmadev) container_of(dmadev, struct k3_dma_dev, slave)
  
  static struct k3_dma_chan *to_k3_chan(struct dma_chan *chan)
  {
  	return container_of(chan, struct k3_dma_chan, vc.chan);
  }
  
  static void k3_dma_pause_dma(struct k3_dma_phy *phy, bool on)
  {
  	u32 val = 0;
  
  	if (on) {
  		val = readl_relaxed(phy->base + CX_CFG);
  		val |= CX_CFG_EN;
  		writel_relaxed(val, phy->base + CX_CFG);
  	} else {
  		val = readl_relaxed(phy->base + CX_CFG);
  		val &= ~CX_CFG_EN;
  		writel_relaxed(val, phy->base + CX_CFG);
  	}
  }
  
  static void k3_dma_terminate_chan(struct k3_dma_phy *phy, struct k3_dma_dev *d)
  {
  	u32 val = 0;
  
  	k3_dma_pause_dma(phy, false);
  
  	val = 0x1 << phy->idx;
  	writel_relaxed(val, d->base + INT_TC1_RAW);
  	writel_relaxed(val, d->base + INT_ERR1_RAW);
  	writel_relaxed(val, d->base + INT_ERR2_RAW);
  }
  
  static void k3_dma_set_desc(struct k3_dma_phy *phy, struct k3_desc_hw *hw)
  {
  	writel_relaxed(hw->lli, phy->base + CX_LLI);
  	writel_relaxed(hw->count, phy->base + CX_CNT);
  	writel_relaxed(hw->saddr, phy->base + CX_SRC);
  	writel_relaxed(hw->daddr, phy->base + CX_DST);
  	writel_relaxed(AXI_CFG_DEFAULT, phy->base + AXI_CFG);
  	writel_relaxed(hw->config, phy->base + CX_CFG);
  }
  
  static u32 k3_dma_get_curr_cnt(struct k3_dma_dev *d, struct k3_dma_phy *phy)
  {
  	u32 cnt = 0;
  
  	cnt = readl_relaxed(d->base + CX_CUR_CNT + phy->idx * 0x10);
  	cnt &= 0xffff;
  	return cnt;
  }
  
  static u32 k3_dma_get_curr_lli(struct k3_dma_phy *phy)
  {
  	return readl_relaxed(phy->base + CX_LLI);
  }
  
  static u32 k3_dma_get_chan_stat(struct k3_dma_dev *d)
  {
  	return readl_relaxed(d->base + CH_STAT);
  }
  
  static void k3_dma_enable_dma(struct k3_dma_dev *d, bool on)
  {
  	if (on) {
  		/* set same priority */
  		writel_relaxed(0x0, d->base + CH_PRI);
  
  		/* unmask irq */
  		writel_relaxed(0xffff, d->base + INT_TC1_MASK);
  		writel_relaxed(0xffff, d->base + INT_ERR1_MASK);
  		writel_relaxed(0xffff, d->base + INT_ERR2_MASK);
  	} else {
  		/* mask irq */
  		writel_relaxed(0x0, d->base + INT_TC1_MASK);
  		writel_relaxed(0x0, d->base + INT_ERR1_MASK);
  		writel_relaxed(0x0, d->base + INT_ERR2_MASK);
  	}
  }
  
  static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
  {
  	struct k3_dma_dev *d = (struct k3_dma_dev *)dev_id;
  	struct k3_dma_phy *p;
  	struct k3_dma_chan *c;
  	u32 stat = readl_relaxed(d->base + INT_STAT);
  	u32 tc1  = readl_relaxed(d->base + INT_TC1);
  	u32 err1 = readl_relaxed(d->base + INT_ERR1);
  	u32 err2 = readl_relaxed(d->base + INT_ERR2);
  	u32 i, irq_chan = 0;
  
  	while (stat) {
  		i = __ffs(stat);
  		stat &= (stat - 1);
  		if (likely(tc1 & BIT(i))) {
  			p = &d->phy[i];
  			c = p->vchan;
  			if (c) {
  				unsigned long flags;
  
  				spin_lock_irqsave(&c->vc.lock, flags);
  				vchan_cookie_complete(&p->ds_run->vd);
  				p->ds_done = p->ds_run;
  				spin_unlock_irqrestore(&c->vc.lock, flags);
  			}
  			irq_chan |= BIT(i);
  		}
  		if (unlikely((err1 & BIT(i)) || (err2 & BIT(i))))
  			dev_warn(d->slave.dev, "DMA ERR
  ");
  	}
  
  	writel_relaxed(irq_chan, d->base + INT_TC1_RAW);
  	writel_relaxed(err1, d->base + INT_ERR1_RAW);
  	writel_relaxed(err2, d->base + INT_ERR2_RAW);
  
  	if (irq_chan) {
  		tasklet_schedule(&d->task);
  		return IRQ_HANDLED;
  	} else
  		return IRQ_NONE;
  }
  
  static int k3_dma_start_txd(struct k3_dma_chan *c)
  {
  	struct k3_dma_dev *d = to_k3_dma(c->vc.chan.device);
  	struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
  
  	if (!c->phy)
  		return -EAGAIN;
  
  	if (BIT(c->phy->idx) & k3_dma_get_chan_stat(d))
  		return -EAGAIN;
  
  	if (vd) {
  		struct k3_dma_desc_sw *ds =
  			container_of(vd, struct k3_dma_desc_sw, vd);
  		/*
  		 * fetch and remove request from vc->desc_issued
  		 * so vc->desc_issued only contains desc pending
  		 */
  		list_del(&ds->vd.node);
  		c->phy->ds_run = ds;
  		c->phy->ds_done = NULL;
  		/* start dma */
  		k3_dma_set_desc(c->phy, &ds->desc_hw[0]);
  		return 0;
  	}
  	c->phy->ds_done = NULL;
  	c->phy->ds_run = NULL;
  	return -EAGAIN;
  }
  
  static void k3_dma_tasklet(unsigned long arg)
  {
  	struct k3_dma_dev *d = (struct k3_dma_dev *)arg;
  	struct k3_dma_phy *p;
  	struct k3_dma_chan *c, *cn;
  	unsigned pch, pch_alloc = 0;
  
  	/* check new dma request of running channel in vc->desc_issued */
  	list_for_each_entry_safe(c, cn, &d->slave.channels, vc.chan.device_node) {
  		spin_lock_irq(&c->vc.lock);
  		p = c->phy;
  		if (p && p->ds_done) {
  			if (k3_dma_start_txd(c)) {
  				/* No current txd associated with this channel */
  				dev_dbg(d->slave.dev, "pchan %u: free
  ", p->idx);
  				/* Mark this channel free */
  				c->phy = NULL;
  				p->vchan = NULL;
  			}
  		}
  		spin_unlock_irq(&c->vc.lock);
  	}
  
  	/* check new channel request in d->chan_pending */
  	spin_lock_irq(&d->lock);
  	for (pch = 0; pch < d->dma_channels; pch++) {
  		p = &d->phy[pch];
  
  		if (p->vchan == NULL && !list_empty(&d->chan_pending)) {
  			c = list_first_entry(&d->chan_pending,
  				struct k3_dma_chan, node);
  			/* remove from d->chan_pending */
  			list_del_init(&c->node);
  			pch_alloc |= 1 << pch;
  			/* Mark this channel allocated */
  			p->vchan = c;
  			c->phy = p;
  			dev_dbg(d->slave.dev, "pchan %u: alloc vchan %p
  ", pch, &c->vc);
  		}
  	}
  	spin_unlock_irq(&d->lock);
  
  	for (pch = 0; pch < d->dma_channels; pch++) {
  		if (pch_alloc & (1 << pch)) {
  			p = &d->phy[pch];
  			c = p->vchan;
  			if (c) {
  				spin_lock_irq(&c->vc.lock);
  				k3_dma_start_txd(c);
  				spin_unlock_irq(&c->vc.lock);
  			}
  		}
  	}
  }
  
  static int k3_dma_alloc_chan_resources(struct dma_chan *chan)
  {
  	return 0;
  }
  
  static void k3_dma_free_chan_resources(struct dma_chan *chan)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_dev *d = to_k3_dma(chan->device);
  	unsigned long flags;
  
  	spin_lock_irqsave(&d->lock, flags);
  	list_del_init(&c->node);
  	spin_unlock_irqrestore(&d->lock, flags);
  
  	vchan_free_chan_resources(&c->vc);
  	c->ccfg = 0;
  }
  
  static enum dma_status k3_dma_tx_status(struct dma_chan *chan,
  	dma_cookie_t cookie, struct dma_tx_state *state)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_dev *d = to_k3_dma(chan->device);
  	struct k3_dma_phy *p;
  	struct virt_dma_desc *vd;
  	unsigned long flags;
  	enum dma_status ret;
  	size_t bytes = 0;
  
  	ret = dma_cookie_status(&c->vc.chan, cookie, state);
  	if (ret == DMA_COMPLETE)
  		return ret;
  
  	spin_lock_irqsave(&c->vc.lock, flags);
  	p = c->phy;
  	ret = c->status;
  
  	/*
  	 * If the cookie is on our issue queue, then the residue is
  	 * its total size.
  	 */
  	vd = vchan_find_desc(&c->vc, cookie);
  	if (vd) {
  		bytes = container_of(vd, struct k3_dma_desc_sw, vd)->size;
  	} else if ((!p) || (!p->ds_run)) {
  		bytes = 0;
  	} else {
  		struct k3_dma_desc_sw *ds = p->ds_run;
  		u32 clli = 0, index = 0;
  
  		bytes = k3_dma_get_curr_cnt(d, p);
  		clli = k3_dma_get_curr_lli(p);
  		index = (clli - ds->desc_hw_lli) / sizeof(struct k3_desc_hw);
  		for (; index < ds->desc_num; index++) {
  			bytes += ds->desc_hw[index].count;
  			/* end of lli */
  			if (!ds->desc_hw[index].lli)
  				break;
  		}
  	}
  	spin_unlock_irqrestore(&c->vc.lock, flags);
  	dma_set_residue(state, bytes);
  	return ret;
  }
  
  static void k3_dma_issue_pending(struct dma_chan *chan)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_dev *d = to_k3_dma(chan->device);
  	unsigned long flags;
  
  	spin_lock_irqsave(&c->vc.lock, flags);
  	/* add request to vc->desc_issued */
  	if (vchan_issue_pending(&c->vc)) {
  		spin_lock(&d->lock);
  		if (!c->phy) {
  			if (list_empty(&c->node)) {
  				/* if new channel, add chan_pending */
  				list_add_tail(&c->node, &d->chan_pending);
  				/* check in tasklet */
  				tasklet_schedule(&d->task);
  				dev_dbg(d->slave.dev, "vchan %p: issued
  ", &c->vc);
  			}
  		}
  		spin_unlock(&d->lock);
  	} else
  		dev_dbg(d->slave.dev, "vchan %p: nothing to issue
  ", &c->vc);
  	spin_unlock_irqrestore(&c->vc.lock, flags);
  }
  
  static void k3_dma_fill_desc(struct k3_dma_desc_sw *ds, dma_addr_t dst,
  			dma_addr_t src, size_t len, u32 num, u32 ccfg)
  {
  	if ((num + 1) < ds->desc_num)
  		ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
  			sizeof(struct k3_desc_hw);
  	ds->desc_hw[num].lli |= CX_LLI_CHAIN_EN;
  	ds->desc_hw[num].count = len;
  	ds->desc_hw[num].saddr = src;
  	ds->desc_hw[num].daddr = dst;
  	ds->desc_hw[num].config = ccfg;
  }
  
  static struct dma_async_tx_descriptor *k3_dma_prep_memcpy(
  	struct dma_chan *chan,	dma_addr_t dst, dma_addr_t src,
  	size_t len, unsigned long flags)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_desc_sw *ds;
  	size_t copy = 0;
  	int num = 0;
  
  	if (!len)
  		return NULL;
  
  	num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
  	ds = kzalloc(sizeof(*ds) + num * sizeof(ds->desc_hw[0]), GFP_ATOMIC);
  	if (!ds) {
  		dev_dbg(chan->device->dev, "vchan %p: kzalloc fail
  ", &c->vc);
  		return NULL;
  	}
  	ds->desc_hw_lli = __virt_to_phys((unsigned long)&ds->desc_hw[0]);
  	ds->size = len;
  	ds->desc_num = num;
  	num = 0;
  
  	if (!c->ccfg) {
  		/* default is memtomem, without calling device_control */
  		c->ccfg = CX_CFG_SRCINCR | CX_CFG_DSTINCR | CX_CFG_EN;
  		c->ccfg |= (0xf << 20) | (0xf << 24);	/* burst = 16 */
  		c->ccfg |= (0x3 << 12) | (0x3 << 16);	/* width = 64 bit */
  	}
  
  	do {
  		copy = min_t(size_t, len, DMA_MAX_SIZE);
  		k3_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
  
  		if (c->dir == DMA_MEM_TO_DEV) {
  			src += copy;
  		} else if (c->dir == DMA_DEV_TO_MEM) {
  			dst += copy;
  		} else {
  			src += copy;
  			dst += copy;
  		}
  		len -= copy;
  	} while (len);
  
  	ds->desc_hw[num-1].lli = 0;	/* end of link */
  	return vchan_tx_prep(&c->vc, &ds->vd, flags);
  }
  
  static struct dma_async_tx_descriptor *k3_dma_prep_slave_sg(
  	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
  	enum dma_transfer_direction dir, unsigned long flags, void *context)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_desc_sw *ds;
  	size_t len, avail, total = 0;
  	struct scatterlist *sg;
  	dma_addr_t addr, src = 0, dst = 0;
  	int num = sglen, i;
  
  	if (sgl == NULL)
  		return NULL;
  
  	for_each_sg(sgl, sg, sglen, i) {
  		avail = sg_dma_len(sg);
  		if (avail > DMA_MAX_SIZE)
  			num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
  	}
  
  	ds = kzalloc(sizeof(*ds) + num * sizeof(ds->desc_hw[0]), GFP_ATOMIC);
  	if (!ds) {
  		dev_dbg(chan->device->dev, "vchan %p: kzalloc fail
  ", &c->vc);
  		return NULL;
  	}
  	ds->desc_hw_lli = __virt_to_phys((unsigned long)&ds->desc_hw[0]);
  	ds->desc_num = num;
  	num = 0;
  
  	for_each_sg(sgl, sg, sglen, i) {
  		addr = sg_dma_address(sg);
  		avail = sg_dma_len(sg);
  		total += avail;
  
  		do {
  			len = min_t(size_t, avail, DMA_MAX_SIZE);
  
  			if (dir == DMA_MEM_TO_DEV) {
  				src = addr;
  				dst = c->dev_addr;
  			} else if (dir == DMA_DEV_TO_MEM) {
  				src = c->dev_addr;
  				dst = addr;
  			}
  
  			k3_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
  
  			addr += len;
  			avail -= len;
  		} while (avail);
  	}
  
  	ds->desc_hw[num-1].lli = 0;	/* end of link */
  	ds->size = total;
  	return vchan_tx_prep(&c->vc, &ds->vd, flags);
  }
  
  static int k3_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
  	unsigned long arg)
  {
  	struct k3_dma_chan *c = to_k3_chan(chan);
  	struct k3_dma_dev *d = to_k3_dma(chan->device);
  	struct dma_slave_config *cfg = (void *)arg;
  	struct k3_dma_phy *p = c->phy;
  	unsigned long flags;
  	u32 maxburst = 0, val = 0;
  	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
  	LIST_HEAD(head);
  
  	switch (cmd) {
  	case DMA_SLAVE_CONFIG:
  		if (cfg == NULL)
  			return -EINVAL;
  		c->dir = cfg->direction;
  		if (c->dir == DMA_DEV_TO_MEM) {
  			c->ccfg = CX_CFG_DSTINCR;
  			c->dev_addr = cfg->src_addr;
  			maxburst = cfg->src_maxburst;
  			width = cfg->src_addr_width;
  		} else if (c->dir == DMA_MEM_TO_DEV) {
  			c->ccfg = CX_CFG_SRCINCR;
  			c->dev_addr = cfg->dst_addr;
  			maxburst = cfg->dst_maxburst;
  			width = cfg->dst_addr_width;
  		}
  		switch (width) {
  		case DMA_SLAVE_BUSWIDTH_1_BYTE:
  		case DMA_SLAVE_BUSWIDTH_2_BYTES:
  		case DMA_SLAVE_BUSWIDTH_4_BYTES:
  		case DMA_SLAVE_BUSWIDTH_8_BYTES:
  			val =  __ffs(width);
  			break;
  		default:
  			val = 3;
  			break;
  		}
  		c->ccfg |= (val << 12) | (val << 16);
  
  		if ((maxburst == 0) || (maxburst > 16))
  			val = 16;
  		else
  			val = maxburst - 1;
  		c->ccfg |= (val << 20) | (val << 24);
  		c->ccfg |= CX_CFG_MEM2PER | CX_CFG_EN;
  
  		/* specific request line */
  		c->ccfg |= c->vc.chan.chan_id << 4;
  		break;
  
  	case DMA_TERMINATE_ALL:
  		dev_dbg(d->slave.dev, "vchan %p: terminate all
  ", &c->vc);
  
  		/* Prevent this channel being scheduled */
  		spin_lock(&d->lock);
  		list_del_init(&c->node);
  		spin_unlock(&d->lock);
  
  		/* Clear the tx descriptor lists */
  		spin_lock_irqsave(&c->vc.lock, flags);
  		vchan_get_all_descriptors(&c->vc, &head);
  		if (p) {
  			/* vchan is assigned to a pchan - stop the channel */
  			k3_dma_terminate_chan(p, d);
  			c->phy = NULL;
  			p->vchan = NULL;
  			p->ds_run = p->ds_done = NULL;
  		}
  		spin_unlock_irqrestore(&c->vc.lock, flags);
  		vchan_dma_desc_free_list(&c->vc, &head);
  		break;
  
  	case DMA_PAUSE:
  		dev_dbg(d->slave.dev, "vchan %p: pause
  ", &c->vc);
  		if (c->status == DMA_IN_PROGRESS) {
  			c->status = DMA_PAUSED;
  			if (p) {
  				k3_dma_pause_dma(p, false);
  			} else {
  				spin_lock(&d->lock);
  				list_del_init(&c->node);
  				spin_unlock(&d->lock);
  			}
  		}
  		break;
  
  	case DMA_RESUME:
  		dev_dbg(d->slave.dev, "vchan %p: resume
  ", &c->vc);
  		spin_lock_irqsave(&c->vc.lock, flags);
  		if (c->status == DMA_PAUSED) {
  			c->status = DMA_IN_PROGRESS;
  			if (p) {
  				k3_dma_pause_dma(p, true);
  			} else if (!list_empty(&c->vc.desc_issued)) {
  				spin_lock(&d->lock);
  				list_add_tail(&c->node, &d->chan_pending);
  				spin_unlock(&d->lock);
  			}
  		}
  		spin_unlock_irqrestore(&c->vc.lock, flags);
  		break;
  	default:
  		return -ENXIO;
  	}
  	return 0;
  }
  
  static void k3_dma_free_desc(struct virt_dma_desc *vd)
  {
  	struct k3_dma_desc_sw *ds =
  		container_of(vd, struct k3_dma_desc_sw, vd);
  
  	kfree(ds);
  }
  
  static struct of_device_id k3_pdma_dt_ids[] = {
  	{ .compatible = "hisilicon,k3-dma-1.0", },
  	{}
  };
  MODULE_DEVICE_TABLE(of, k3_pdma_dt_ids);
  
  static struct dma_chan *k3_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
  						struct of_dma *ofdma)
  {
  	struct k3_dma_dev *d = ofdma->of_dma_data;
  	unsigned int request = dma_spec->args[0];
  
  	if (request > d->dma_requests)
  		return NULL;
  
  	return dma_get_slave_channel(&(d->chans[request].vc.chan));
  }
  
  static int k3_dma_probe(struct platform_device *op)
  {
  	struct k3_dma_dev *d;
  	const struct of_device_id *of_id;
  	struct resource *iores;
  	int i, ret, irq = 0;
  
  	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
  	if (!iores)
  		return -EINVAL;
  
  	d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
  	if (!d)
  		return -ENOMEM;
  
  	d->base = devm_ioremap_resource(&op->dev, iores);
  	if (IS_ERR(d->base))
  		return PTR_ERR(d->base);
  
  	of_id = of_match_device(k3_pdma_dt_ids, &op->dev);
  	if (of_id) {
  		of_property_read_u32((&op->dev)->of_node,
  				"dma-channels", &d->dma_channels);
  		of_property_read_u32((&op->dev)->of_node,
  				"dma-requests", &d->dma_requests);
  	}
  
  	d->clk = devm_clk_get(&op->dev, NULL);
  	if (IS_ERR(d->clk)) {
  		dev_err(&op->dev, "no dma clk
  ");
  		return PTR_ERR(d->clk);
  	}
  
  	irq = platform_get_irq(op, 0);
  	ret = devm_request_irq(&op->dev, irq,
  			k3_dma_int_handler, 0, DRIVER_NAME, d);
  	if (ret)
  		return ret;
  
  	/* init phy channel */
  	d->phy = devm_kzalloc(&op->dev,
  		d->dma_channels * sizeof(struct k3_dma_phy), GFP_KERNEL);
  	if (d->phy == NULL)
  		return -ENOMEM;
  
  	for (i = 0; i < d->dma_channels; i++) {
  		struct k3_dma_phy *p = &d->phy[i];
  
  		p->idx = i;
  		p->base = d->base + i * 0x40;
  	}
  
  	INIT_LIST_HEAD(&d->slave.channels);
  	dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
  	dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
  	d->slave.dev = &op->dev;
  	d->slave.device_alloc_chan_resources = k3_dma_alloc_chan_resources;
  	d->slave.device_free_chan_resources = k3_dma_free_chan_resources;
  	d->slave.device_tx_status = k3_dma_tx_status;
  	d->slave.device_prep_dma_memcpy = k3_dma_prep_memcpy;
  	d->slave.device_prep_slave_sg = k3_dma_prep_slave_sg;
  	d->slave.device_issue_pending = k3_dma_issue_pending;
  	d->slave.device_control = k3_dma_control;
  	d->slave.copy_align = DMA_ALIGN;
  	d->slave.chancnt = d->dma_requests;
  
  	/* init virtual channel */
  	d->chans = devm_kzalloc(&op->dev,
  		d->dma_requests * sizeof(struct k3_dma_chan), GFP_KERNEL);
  	if (d->chans == NULL)
  		return -ENOMEM;
  
  	for (i = 0; i < d->dma_requests; i++) {
  		struct k3_dma_chan *c = &d->chans[i];
  
  		c->status = DMA_IN_PROGRESS;
  		INIT_LIST_HEAD(&c->node);
  		c->vc.desc_free = k3_dma_free_desc;
  		vchan_init(&c->vc, &d->slave);
  	}
  
  	/* Enable clock before accessing registers */
  	ret = clk_prepare_enable(d->clk);
  	if (ret < 0) {
  		dev_err(&op->dev, "clk_prepare_enable failed: %d
  ", ret);
  		return ret;
  	}
  
  	k3_dma_enable_dma(d, true);
  
  	ret = dma_async_device_register(&d->slave);
  	if (ret)
  		return ret;
  
  	ret = of_dma_controller_register((&op->dev)->of_node,
  					k3_of_dma_simple_xlate, d);
  	if (ret)
  		goto of_dma_register_fail;
  
  	spin_lock_init(&d->lock);
  	INIT_LIST_HEAD(&d->chan_pending);
  	tasklet_init(&d->task, k3_dma_tasklet, (unsigned long)d);
  	platform_set_drvdata(op, d);
  	dev_info(&op->dev, "initialized
  ");
  
  	return 0;
  
  of_dma_register_fail:
  	dma_async_device_unregister(&d->slave);
  	return ret;
  }
  
  static int k3_dma_remove(struct platform_device *op)
  {
  	struct k3_dma_chan *c, *cn;
  	struct k3_dma_dev *d = platform_get_drvdata(op);
  
  	dma_async_device_unregister(&d->slave);
  	of_dma_controller_free((&op->dev)->of_node);
  
  	list_for_each_entry_safe(c, cn, &d->slave.channels, vc.chan.device_node) {
  		list_del(&c->vc.chan.device_node);
  		tasklet_kill(&c->vc.task);
  	}
  	tasklet_kill(&d->task);
  	clk_disable_unprepare(d->clk);
  	return 0;
  }
  
  static int k3_dma_suspend(struct device *dev)
  {
  	struct k3_dma_dev *d = dev_get_drvdata(dev);
  	u32 stat = 0;
  
  	stat = k3_dma_get_chan_stat(d);
  	if (stat) {
  		dev_warn(d->slave.dev,
  			"chan %d is running fail to suspend
  ", stat);
  		return -1;
  	}
  	k3_dma_enable_dma(d, false);
  	clk_disable_unprepare(d->clk);
  	return 0;
  }
  
  static int k3_dma_resume(struct device *dev)
  {
  	struct k3_dma_dev *d = dev_get_drvdata(dev);
  	int ret = 0;
  
  	ret = clk_prepare_enable(d->clk);
  	if (ret < 0) {
  		dev_err(d->slave.dev, "clk_prepare_enable failed: %d
  ", ret);
  		return ret;
  	}
  	k3_dma_enable_dma(d, true);
  	return 0;
  }
  
  static SIMPLE_DEV_PM_OPS(k3_dma_pmops, k3_dma_suspend, k3_dma_resume);
  
  static struct platform_driver k3_pdma_driver = {
  	.driver		= {
  		.name	= DRIVER_NAME,
  		.owner  = THIS_MODULE,
  		.pm	= &k3_dma_pmops,
  		.of_match_table = k3_pdma_dt_ids,
  	},
  	.probe		= k3_dma_probe,
  	.remove		= k3_dma_remove,
  };
  
  module_platform_driver(k3_pdma_driver);
  
  MODULE_DESCRIPTION("Hisilicon k3 DMA Driver");
  MODULE_ALIAS("platform:k3dma");
  MODULE_LICENSE("GPL v2");