// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2013 - 2015 Linaro Ltd.
 * Copyright (c) 2013 Hisilicon Limited.
 */
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.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_MAX_SIZE            0x1ffc
#define DMA_CYCLIC_MAX_PERIOD   0x1000
#define LLI_BLOCK_SIZE          (4 * PAGE_SIZE)

#define INT_STAT                0x00
#define INT_TC1                 0x04
#define INT_TC2                 0x08
#define INT_ERR1                0x0c
#define INT_ERR2                0x10
#define INT_TC1_MASK            0x18
#define INT_TC2_MASK            0x1c
#define INT_ERR1_MASK           0x20
#define INT_ERR2_MASK           0x24
#define INT_TC1_RAW             0x600
#define INT_TC2_RAW             0x608
#define INT_ERR1_RAW            0x610
#define INT_ERR2_RAW            0x618
#define CH_PRI                  0x688
#define CH_STAT                 0x690
#define CX_CUR_CNT              0x704
#define CX_LLI                  0x800
#define CX_CNT1                 0x80c
#define CX_CNT0                 0x810
#define CX_SRC                  0x814
#define CX_DST                  0x818
#define CX_CFG                  0x81c

#define CX_LLI_CHAIN_EN         0x2
#define CX_CFG_EN               0x1
#define CX_CFG_NODEIRQ          BIT(1)
#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;
};

struct k3_dma_phy;

struct k3_dma_chan {
        u32                     ccfg;
        struct virt_dma_chan    vc;
        struct k3_dma_phy       *phy;
        struct list_head        node;
        dma_addr_t              dev_addr;
        enum dma_status         status;
        bool                    cyclic;
        struct dma_slave_config slave_config;
};

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;
        struct dma_pool         *pool;
        u32                     dma_channels;
        u32                     dma_requests;
        u32                     dma_channel_mask;
        unsigned int            irq;
};


#define K3_FLAG_NOCLK   BIT(1)

struct k3dma_soc_data {
        unsigned long flags;
};


#define to_k3_dma(dmadev) container_of(dmadev, struct k3_dma_dev, slave)

static int k3_dma_config_write(struct dma_chan *chan,
                               enum dma_transfer_direction dir,
                               struct dma_slave_config *cfg);

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_TC2_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_CNT0);
        writel_relaxed(hw->saddr, phy->base + CX_SRC);
        writel_relaxed(hw->daddr, phy->base + CX_DST);
        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_TC2_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_TC2_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 tc2  = readl_relaxed(d->base + INT_TC2);
        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 &= ~BIT(i);
                if (likely(tc1 & BIT(i)) || (tc2 & BIT(i))) {
                        unsigned long flags;

                        p = &d->phy[i];
                        c = p->vchan;
                        if (c && (tc1 & BIT(i))) {
                                spin_lock_irqsave(&c->vc.lock, flags);
                                if (p->ds_run != NULL) {
                                        vchan_cookie_complete(&p->ds_run->vd);
                                        p->ds_done = p->ds_run;
                                        p->ds_run = NULL;
                                }
                                spin_unlock_irqrestore(&c->vc.lock, flags);
                        }
                        if (c && (tc2 & BIT(i))) {
                                spin_lock_irqsave(&c->vc.lock, flags);
                                if (p->ds_run != NULL)
                                        vchan_cyclic_callback(&p->ds_run->vd);
                                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\n");
        }

        writel_relaxed(irq_chan, d->base + INT_TC1_RAW);
        writel_relaxed(irq_chan, d->base + INT_TC2_RAW);
        writel_relaxed(err1, d->base + INT_ERR1_RAW);
        writel_relaxed(err2, d->base + INT_ERR2_RAW);

        if (irq_chan)
                tasklet_schedule(&d->task);

        if (irq_chan || err1 || err2)
                return IRQ_HANDLED;

        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;

        /* Avoid losing track of  ds_run if a transaction is in flight */
        if (c->phy->ds_run)
                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_run = NULL;
        c->phy->ds_done = 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\n", 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++) {
                if (!(d->dma_channel_mask & (1 << pch)))
                        continue;

                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\n", pch, &c->vc);
                }
        }
        spin_unlock_irq(&d->lock);

        for (pch = 0; pch < d->dma_channels; pch++) {
                if (!(d->dma_channel_mask & (1 << pch)))
                        continue;

                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 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 && !c->cyclic) {
                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)) + 1;
                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\n", &c->vc);
                        }
                }
                spin_unlock(&d->lock);
        } else
                dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &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 != ds->desc_num - 1)
                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 k3_dma_desc_sw *k3_dma_alloc_desc_resource(int num,
                                                        struct dma_chan *chan)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        struct k3_dma_desc_sw *ds;
        struct k3_dma_dev *d = to_k3_dma(chan->device);
        int lli_limit = LLI_BLOCK_SIZE / sizeof(struct k3_desc_hw);

        if (num > lli_limit) {
                dev_dbg(chan->device->dev, "vch %p: sg num %d exceed max %d\n",
                        &c->vc, num, lli_limit);
                return NULL;
        }

        ds = kzalloc(sizeof(*ds), GFP_NOWAIT);
        if (!ds)
                return NULL;

        ds->desc_hw = dma_pool_zalloc(d->pool, GFP_NOWAIT, &ds->desc_hw_lli);
        if (!ds->desc_hw) {
                dev_dbg(chan->device->dev, "vch %p: dma alloc fail\n", &c->vc);
                kfree(ds);
                return NULL;
        }
        ds->desc_num = num;
        return ds;
}

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 = k3_dma_alloc_desc_resource(num, chan);
        if (!ds)
                return NULL;

        c->cyclic = 0;
        ds->size = len;
        num = 0;

        if (!c->ccfg) {
                /* default is memtomem, without calling device_config */
                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);

                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;

        c->cyclic = 0;

        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 = k3_dma_alloc_desc_resource(num, chan);
        if (!ds)
                return NULL;
        num = 0;
        k3_dma_config_write(chan, dir, &c->slave_config);

        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 struct dma_async_tx_descriptor *
k3_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr,
                       size_t buf_len, size_t period_len,
                       enum dma_transfer_direction dir,
                       unsigned long flags)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        struct k3_dma_desc_sw *ds;
        size_t len, avail, total = 0;
        dma_addr_t addr, src = 0, dst = 0;
        int num = 1, since = 0;
        size_t modulo = DMA_CYCLIC_MAX_PERIOD;
        u32 en_tc2 = 0;

        dev_dbg(chan->device->dev, "%s: buf %pad, dst %pad, buf len %zu, period_len = %zu, dir %d\n",
               __func__, &buf_addr, &to_k3_chan(chan)->dev_addr,
               buf_len, period_len, (int)dir);

        avail = buf_len;
        if (avail > modulo)
                num += DIV_ROUND_UP(avail, modulo) - 1;

        ds = k3_dma_alloc_desc_resource(num, chan);
        if (!ds)
                return NULL;

        c->cyclic = 1;
        addr = buf_addr;
        avail = buf_len;
        total = avail;
        num = 0;
        k3_dma_config_write(chan, dir, &c->slave_config);

        if (period_len < modulo)
                modulo = period_len;

        do {
                len = min_t(size_t, avail, modulo);

                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;
                }
                since += len;
                if (since >= period_len) {
                        /* descriptor asks for TC2 interrupt on completion */
                        en_tc2 = CX_CFG_NODEIRQ;
                        since -= period_len;
                } else
                        en_tc2 = 0;

                k3_dma_fill_desc(ds, dst, src, len, num++, c->ccfg | en_tc2);

                addr += len;
                avail -= len;
        } while (avail);

        /* "Cyclic" == end of link points back to start of link */
        ds->desc_hw[num - 1].lli |= ds->desc_hw_lli;

        ds->size = total;

        return vchan_tx_prep(&c->vc, &ds->vd, flags);
}

static int k3_dma_config(struct dma_chan *chan,
                         struct dma_slave_config *cfg)
{
        struct k3_dma_chan *c = to_k3_chan(chan);

        memcpy(&c->slave_config, cfg, sizeof(*cfg));

        return 0;
}

static int k3_dma_config_write(struct dma_chan *chan,
                               enum dma_transfer_direction dir,
                               struct dma_slave_config *cfg)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        u32 maxburst = 0, val = 0;
        enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;

        if (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 (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 = 15;
        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;

        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);
        struct k3_dma_dev *d = to_k3_dma(vd->tx.chan->device);

        dma_pool_free(d->pool, ds->desc_hw, ds->desc_hw_lli);
        kfree(ds);
}

static int k3_dma_terminate_all(struct dma_chan *chan)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        struct k3_dma_dev *d = to_k3_dma(chan->device);
        struct k3_dma_phy *p = c->phy;
        unsigned long flags;
        LIST_HEAD(head);

        dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &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;
                if (p->ds_run) {
                        vchan_terminate_vdesc(&p->ds_run->vd);
                        p->ds_run = NULL;
                }
                p->ds_done = NULL;
        }
        spin_unlock_irqrestore(&c->vc.lock, flags);
        vchan_dma_desc_free_list(&c->vc, &head);

        return 0;
}

static void k3_dma_synchronize(struct dma_chan *chan)
{
        struct k3_dma_chan *c = to_k3_chan(chan);

        vchan_synchronize(&c->vc);
}

static int k3_dma_transfer_pause(struct dma_chan *chan)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        struct k3_dma_dev *d = to_k3_dma(chan->device);
        struct k3_dma_phy *p = c->phy;

        dev_dbg(d->slave.dev, "vchan %p: pause\n", &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);
                }
        }

        return 0;
}

static int k3_dma_transfer_resume(struct dma_chan *chan)
{
        struct k3_dma_chan *c = to_k3_chan(chan);
        struct k3_dma_dev *d = to_k3_dma(chan->device);
        struct k3_dma_phy *p = c->phy;
        unsigned long flags;

        dev_dbg(d->slave.dev, "vchan %p: resume\n", &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);

        return 0;
}

static const struct k3dma_soc_data k3_v1_dma_data = {
        .flags = 0,
};

static const struct k3dma_soc_data asp_v1_dma_data = {
        .flags = K3_FLAG_NOCLK,
};

static const struct of_device_id k3_pdma_dt_ids[] = {
        { .compatible = "hisilicon,k3-dma-1.0",
          .data = &k3_v1_dma_data
        },
        { .compatible = "hisilicon,hisi-pcm-asp-dma-1.0",
          .data = &asp_v1_dma_data
        },
        {}
};
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)
{
        const struct k3dma_soc_data *soc_data;
        struct k3_dma_dev *d;
        const struct of_device_id *of_id;
        int i, ret, irq = 0;

        d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
        if (!d)
                return -ENOMEM;

        soc_data = device_get_match_data(&op->dev);
        if (!soc_data)
                return -EINVAL;

        d->base = devm_platform_ioremap_resource(op, 0);
        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);
                ret = of_property_read_u32((&op->dev)->of_node,
                                "dma-channel-mask", &d->dma_channel_mask);
                if (ret) {
                        dev_warn(&op->dev,
                                 "dma-channel-mask doesn't exist, considering all as available.\n");
                        d->dma_channel_mask = (u32)~0UL;
                }
        }

        if (!(soc_data->flags & K3_FLAG_NOCLK)) {
                d->clk = devm_clk_get(&op->dev, NULL);
                if (IS_ERR(d->clk)) {
                        dev_err(&op->dev, "no dma clk\n");
                        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;

        d->irq = irq;

        /* A DMA memory pool for LLIs, align on 32-byte boundary */
        d->pool = dmam_pool_create(DRIVER_NAME, &op->dev,
                                        LLI_BLOCK_SIZE, 32, 0);
        if (!d->pool)
                return -ENOMEM;

        /* init phy channel */
        d->phy = devm_kcalloc(&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;

                if (!(d->dma_channel_mask & BIT(i)))
                        continue;

                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);
        dma_cap_set(DMA_CYCLIC, d->slave.cap_mask);
        d->slave.dev = &op->dev;
        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_prep_dma_cyclic = k3_dma_prep_dma_cyclic;
        d->slave.device_issue_pending = k3_dma_issue_pending;
        d->slave.device_config = k3_dma_config;
        d->slave.device_pause = k3_dma_transfer_pause;
        d->slave.device_resume = k3_dma_transfer_resume;
        d->slave.device_terminate_all = k3_dma_terminate_all;
        d->slave.device_synchronize = k3_dma_synchronize;
        d->slave.copy_align = DMAENGINE_ALIGN_8_BYTES;

        /* init virtual channel */
        d->chans = devm_kcalloc(&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\n", ret);
                return ret;
        }

        k3_dma_enable_dma(d, true);

        ret = dma_async_device_register(&d->slave);
        if (ret)
                goto dma_async_register_fail;

        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\n");

        return 0;

of_dma_register_fail:
        dma_async_device_unregister(&d->slave);
dma_async_register_fail:
        clk_disable_unprepare(d->clk);
        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);

        devm_free_irq(&op->dev, d->irq, d);

        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;
}

#ifdef CONFIG_PM_SLEEP
static int k3_dma_suspend_dev(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\n", stat);
                return -1;
        }
        k3_dma_enable_dma(d, false);
        clk_disable_unprepare(d->clk);
        return 0;
}

static int k3_dma_resume_dev(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\n", ret);
                return ret;
        }
        k3_dma_enable_dma(d, true);
        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(k3_dma_pmops, k3_dma_suspend_dev, k3_dma_resume_dev);

static struct platform_driver k3_pdma_driver = {
        .driver         = {
                .name   = DRIVER_NAME,
                .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");