[PATCH 4.19 209/247] staging/mt7621-dma: mtk-hsdma.c->hsdma-mt7621.c

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>

commit 1f92798cbe7fe923479cff754dd06dd23d352e36 upstream.

Also use KBUILD_MODNAME for module name.

This driver is only used by RALINK MIPS MT7621 SoCs. Tested by building
against that target using OpenWrt with Linux 5.10.10.

Fixes the following error:
error: the following would cause module name conflict:
  drivers/dma/mediatek/mtk-hsdma.ko
  drivers/staging/mt7621-dma/mtk-hsdma.ko

Cc: stable@vger.kernel.org
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Link: https://lore.kernel.org/r/20210130034507.2115280-1-ilya.lipnitskiy@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/mt7621-dma/Makefile       |    2 
 drivers/staging/mt7621-dma/hsdma-mt7621.c |  771 ++++++++++++++++++++++++++++++
 drivers/staging/mt7621-dma/mtk-hsdma.c    |  771 ------------------------------
 3 files changed, 772 insertions(+), 772 deletions(-)
 rename drivers/staging/mt7621-dma/{mtk-hsdma.c => hsdma-mt7621.c} (99%)

--- a/drivers/staging/mt7621-dma/Makefile
+++ b/drivers/staging/mt7621-dma/Makefile
@@ -1,4 +1,4 @@
 obj-$(CONFIG_DMA_RALINK) += ralink-gdma.o
-obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o
+obj-$(CONFIG_MTK_HSDMA) += hsdma-mt7621.o
 
 ccflags-y += -I$(srctree)/drivers/dma
--- /dev/null
+++ b/drivers/staging/mt7621-dma/hsdma-mt7621.c
@@ -0,0 +1,771 @@
+/*
+ *  Copyright (C) 2015, Michael Lee <igvtee@gmail.com>
+ *  MTK HSDMA support
+ *
+ *  This program 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.
+ *
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <linux/of_dma.h>
+#include <linux/reset.h>
+#include <linux/of_device.h>
+
+#include "virt-dma.h"
+
+#define HSDMA_BASE_OFFSET		0x800
+
+#define HSDMA_REG_TX_BASE		0x00
+#define HSDMA_REG_TX_CNT		0x04
+#define HSDMA_REG_TX_CTX		0x08
+#define HSDMA_REG_TX_DTX		0x0c
+#define HSDMA_REG_RX_BASE		0x100
+#define HSDMA_REG_RX_CNT		0x104
+#define HSDMA_REG_RX_CRX		0x108
+#define HSDMA_REG_RX_DRX		0x10c
+#define HSDMA_REG_INFO			0x200
+#define HSDMA_REG_GLO_CFG		0x204
+#define HSDMA_REG_RST_CFG		0x208
+#define HSDMA_REG_DELAY_INT		0x20c
+#define HSDMA_REG_FREEQ_THRES		0x210
+#define HSDMA_REG_INT_STATUS		0x220
+#define HSDMA_REG_INT_MASK		0x228
+#define HSDMA_REG_SCH_Q01		0x280
+#define HSDMA_REG_SCH_Q23		0x284
+
+#define HSDMA_DESCS_MAX			0xfff
+#define HSDMA_DESCS_NUM			8
+#define HSDMA_DESCS_MASK		(HSDMA_DESCS_NUM - 1)
+#define HSDMA_NEXT_DESC(x)		(((x) + 1) & HSDMA_DESCS_MASK)
+
+/* HSDMA_REG_INFO */
+#define HSDMA_INFO_INDEX_MASK		0xf
+#define HSDMA_INFO_INDEX_SHIFT		24
+#define HSDMA_INFO_BASE_MASK		0xff
+#define HSDMA_INFO_BASE_SHIFT		16
+#define HSDMA_INFO_RX_MASK		0xff
+#define HSDMA_INFO_RX_SHIFT		8
+#define HSDMA_INFO_TX_MASK		0xff
+#define HSDMA_INFO_TX_SHIFT		0
+
+/* HSDMA_REG_GLO_CFG */
+#define HSDMA_GLO_TX_2B_OFFSET		BIT(31)
+#define HSDMA_GLO_CLK_GATE		BIT(30)
+#define HSDMA_GLO_BYTE_SWAP		BIT(29)
+#define HSDMA_GLO_MULTI_DMA		BIT(10)
+#define HSDMA_GLO_TWO_BUF		BIT(9)
+#define HSDMA_GLO_32B_DESC		BIT(8)
+#define HSDMA_GLO_BIG_ENDIAN		BIT(7)
+#define HSDMA_GLO_TX_DONE		BIT(6)
+#define HSDMA_GLO_BT_MASK		0x3
+#define HSDMA_GLO_BT_SHIFT		4
+#define HSDMA_GLO_RX_BUSY		BIT(3)
+#define HSDMA_GLO_RX_DMA		BIT(2)
+#define HSDMA_GLO_TX_BUSY		BIT(1)
+#define HSDMA_GLO_TX_DMA		BIT(0)
+
+#define HSDMA_BT_SIZE_16BYTES		(0 << HSDMA_GLO_BT_SHIFT)
+#define HSDMA_BT_SIZE_32BYTES		(1 << HSDMA_GLO_BT_SHIFT)
+#define HSDMA_BT_SIZE_64BYTES		(2 << HSDMA_GLO_BT_SHIFT)
+#define HSDMA_BT_SIZE_128BYTES		(3 << HSDMA_GLO_BT_SHIFT)
+
+#define HSDMA_GLO_DEFAULT		(HSDMA_GLO_MULTI_DMA | \
+		HSDMA_GLO_RX_DMA | HSDMA_GLO_TX_DMA | HSDMA_BT_SIZE_32BYTES)
+
+/* HSDMA_REG_RST_CFG */
+#define HSDMA_RST_RX_SHIFT		16
+#define HSDMA_RST_TX_SHIFT		0
+
+/* HSDMA_REG_DELAY_INT */
+#define HSDMA_DELAY_INT_EN		BIT(15)
+#define HSDMA_DELAY_PEND_OFFSET		8
+#define HSDMA_DELAY_TIME_OFFSET		0
+#define HSDMA_DELAY_TX_OFFSET		16
+#define HSDMA_DELAY_RX_OFFSET		0
+
+#define HSDMA_DELAY_INIT(x)		(HSDMA_DELAY_INT_EN | \
+		((x) << HSDMA_DELAY_PEND_OFFSET))
+#define HSDMA_DELAY(x)			((HSDMA_DELAY_INIT(x) << \
+		HSDMA_DELAY_TX_OFFSET) | HSDMA_DELAY_INIT(x))
+
+/* HSDMA_REG_INT_STATUS */
+#define HSDMA_INT_DELAY_RX_COH		BIT(31)
+#define HSDMA_INT_DELAY_RX_INT		BIT(30)
+#define HSDMA_INT_DELAY_TX_COH		BIT(29)
+#define HSDMA_INT_DELAY_TX_INT		BIT(28)
+#define HSDMA_INT_RX_MASK		0x3
+#define HSDMA_INT_RX_SHIFT		16
+#define HSDMA_INT_RX_Q0			BIT(16)
+#define HSDMA_INT_TX_MASK		0xf
+#define HSDMA_INT_TX_SHIFT		0
+#define HSDMA_INT_TX_Q0			BIT(0)
+
+/* tx/rx dma desc flags */
+#define HSDMA_PLEN_MASK			0x3fff
+#define HSDMA_DESC_DONE			BIT(31)
+#define HSDMA_DESC_LS0			BIT(30)
+#define HSDMA_DESC_PLEN0(_x)		(((_x) & HSDMA_PLEN_MASK) << 16)
+#define HSDMA_DESC_TAG			BIT(15)
+#define HSDMA_DESC_LS1			BIT(14)
+#define HSDMA_DESC_PLEN1(_x)		((_x) & HSDMA_PLEN_MASK)
+
+/* align 4 bytes */
+#define HSDMA_ALIGN_SIZE		3
+/* align size 128bytes */
+#define HSDMA_MAX_PLEN			0x3f80
+
+struct hsdma_desc {
+	u32 addr0;
+	u32 flags;
+	u32 addr1;
+	u32 unused;
+};
+
+struct mtk_hsdma_sg {
+	dma_addr_t src_addr;
+	dma_addr_t dst_addr;
+	u32 len;
+};
+
+struct mtk_hsdma_desc {
+	struct virt_dma_desc vdesc;
+	unsigned int num_sgs;
+	struct mtk_hsdma_sg sg[1];
+};
+
+struct mtk_hsdma_chan {
+	struct virt_dma_chan vchan;
+	unsigned int id;
+	dma_addr_t desc_addr;
+	int tx_idx;
+	int rx_idx;
+	struct hsdma_desc *tx_ring;
+	struct hsdma_desc *rx_ring;
+	struct mtk_hsdma_desc *desc;
+	unsigned int next_sg;
+};
+
+struct mtk_hsdam_engine {
+	struct dma_device ddev;
+	struct device_dma_parameters dma_parms;
+	void __iomem *base;
+	struct tasklet_struct task;
+	volatile unsigned long chan_issued;
+
+	struct mtk_hsdma_chan chan[1];
+};
+
+static inline struct mtk_hsdam_engine *mtk_hsdma_chan_get_dev(
+		struct mtk_hsdma_chan *chan)
+{
+	return container_of(chan->vchan.chan.device, struct mtk_hsdam_engine,
+			ddev);
+}
+
+static inline struct mtk_hsdma_chan *to_mtk_hsdma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct mtk_hsdma_chan, vchan.chan);
+}
+
+static inline struct mtk_hsdma_desc *to_mtk_hsdma_desc(
+		struct virt_dma_desc *vdesc)
+{
+	return container_of(vdesc, struct mtk_hsdma_desc, vdesc);
+}
+
+static inline u32 mtk_hsdma_read(struct mtk_hsdam_engine *hsdma, u32 reg)
+{
+	return readl(hsdma->base + reg);
+}
+
+static inline void mtk_hsdma_write(struct mtk_hsdam_engine *hsdma,
+				   unsigned reg, u32 val)
+{
+	writel(val, hsdma->base + reg);
+}
+
+static void mtk_hsdma_reset_chan(struct mtk_hsdam_engine *hsdma,
+				 struct mtk_hsdma_chan *chan)
+{
+	chan->tx_idx = 0;
+	chan->rx_idx = HSDMA_DESCS_NUM - 1;
+
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CTX, chan->tx_idx);
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CRX, chan->rx_idx);
+
+	mtk_hsdma_write(hsdma, HSDMA_REG_RST_CFG,
+			0x1 << (chan->id + HSDMA_RST_TX_SHIFT));
+	mtk_hsdma_write(hsdma, HSDMA_REG_RST_CFG,
+			0x1 << (chan->id + HSDMA_RST_RX_SHIFT));
+}
+
+static void hsdma_dump_reg(struct mtk_hsdam_engine *hsdma)
+{
+	dev_dbg(hsdma->ddev.dev, "tbase %08x, tcnt %08x, " \
+			"tctx %08x, tdtx: %08x, rbase %08x, " \
+			"rcnt %08x, rctx %08x, rdtx %08x\n",
+			mtk_hsdma_read(hsdma, HSDMA_REG_TX_BASE),
+			mtk_hsdma_read(hsdma, HSDMA_REG_TX_CNT),
+			mtk_hsdma_read(hsdma, HSDMA_REG_TX_CTX),
+			mtk_hsdma_read(hsdma, HSDMA_REG_TX_DTX),
+			mtk_hsdma_read(hsdma, HSDMA_REG_RX_BASE),
+			mtk_hsdma_read(hsdma, HSDMA_REG_RX_CNT),
+			mtk_hsdma_read(hsdma, HSDMA_REG_RX_CRX),
+			mtk_hsdma_read(hsdma, HSDMA_REG_RX_DRX));
+
+	dev_dbg(hsdma->ddev.dev, "info %08x, glo %08x, delay %08x, " \
+			"intr_stat %08x, intr_mask %08x\n",
+			mtk_hsdma_read(hsdma, HSDMA_REG_INFO),
+			mtk_hsdma_read(hsdma, HSDMA_REG_GLO_CFG),
+			mtk_hsdma_read(hsdma, HSDMA_REG_DELAY_INT),
+			mtk_hsdma_read(hsdma, HSDMA_REG_INT_STATUS),
+			mtk_hsdma_read(hsdma, HSDMA_REG_INT_MASK));
+}
+
+static void hsdma_dump_desc(struct mtk_hsdam_engine *hsdma,
+			    struct mtk_hsdma_chan *chan)
+{
+	struct hsdma_desc *tx_desc;
+	struct hsdma_desc *rx_desc;
+	int i;
+
+	dev_dbg(hsdma->ddev.dev, "tx idx: %d, rx idx: %d\n",
+			chan->tx_idx, chan->rx_idx);
+
+	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
+		tx_desc = &chan->tx_ring[i];
+		rx_desc = &chan->rx_ring[i];
+
+		dev_dbg(hsdma->ddev.dev, "%d tx addr0: %08x, flags %08x, " \
+				"tx addr1: %08x, rx addr0 %08x, flags %08x\n",
+				i, tx_desc->addr0, tx_desc->flags, \
+				tx_desc->addr1, rx_desc->addr0, rx_desc->flags);
+	}
+}
+
+static void mtk_hsdma_reset(struct mtk_hsdam_engine *hsdma,
+			    struct mtk_hsdma_chan *chan)
+{
+	int i;
+
+	/* disable dma */
+	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, 0);
+
+	/* disable intr */
+	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, 0);
+
+	/* init desc value */
+	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
+		chan->tx_ring[i].addr0 = 0;
+		chan->tx_ring[i].flags = HSDMA_DESC_LS0 |
+			HSDMA_DESC_DONE;
+	}
+	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
+		chan->rx_ring[i].addr0 = 0;
+		chan->rx_ring[i].flags = 0;
+	}
+
+	/* reset */
+	mtk_hsdma_reset_chan(hsdma, chan);
+
+	/* enable intr */
+	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, HSDMA_INT_RX_Q0);
+
+	/* enable dma */
+	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, HSDMA_GLO_DEFAULT);
+}
+
+static int mtk_hsdma_terminate_all(struct dma_chan *c)
+{
+	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
+	struct mtk_hsdam_engine *hsdma = mtk_hsdma_chan_get_dev(chan);
+	unsigned long timeout;
+	LIST_HEAD(head);
+
+	spin_lock_bh(&chan->vchan.lock);
+	chan->desc = NULL;
+	clear_bit(chan->id, &hsdma->chan_issued);
+	vchan_get_all_descriptors(&chan->vchan, &head);
+	spin_unlock_bh(&chan->vchan.lock);
+
+	vchan_dma_desc_free_list(&chan->vchan, &head);
+
+	/* wait dma transfer complete */
+	timeout = jiffies + msecs_to_jiffies(2000);
+	while (mtk_hsdma_read(hsdma, HSDMA_REG_GLO_CFG) &
+			(HSDMA_GLO_RX_BUSY | HSDMA_GLO_TX_BUSY)) {
+		if (time_after_eq(jiffies, timeout)) {
+			hsdma_dump_desc(hsdma, chan);
+			mtk_hsdma_reset(hsdma, chan);
+			dev_err(hsdma->ddev.dev, "timeout, reset it\n");
+			break;
+		}
+		cpu_relax();
+	}
+
+	return 0;
+}
+
+static int mtk_hsdma_start_transfer(struct mtk_hsdam_engine *hsdma,
+				    struct mtk_hsdma_chan *chan)
+{
+	dma_addr_t src, dst;
+	size_t len, tlen;
+	struct hsdma_desc *tx_desc, *rx_desc;
+	struct mtk_hsdma_sg *sg;
+	unsigned int i;
+	int rx_idx;
+
+	sg = &chan->desc->sg[0];
+	len = sg->len;
+	chan->desc->num_sgs = DIV_ROUND_UP(len, HSDMA_MAX_PLEN);
+
+	/* tx desc */
+	src = sg->src_addr;
+	for (i = 0; i < chan->desc->num_sgs; i++) {
+		tx_desc = &chan->tx_ring[chan->tx_idx];
+
+		if (len > HSDMA_MAX_PLEN)
+			tlen = HSDMA_MAX_PLEN;
+		else
+			tlen = len;
+
+		if (i & 0x1) {
+			tx_desc->addr1 = src;
+			tx_desc->flags |= HSDMA_DESC_PLEN1(tlen);
+		} else {
+			tx_desc->addr0 = src;
+			tx_desc->flags = HSDMA_DESC_PLEN0(tlen);
+
+			/* update index */
+			chan->tx_idx = HSDMA_NEXT_DESC(chan->tx_idx);
+		}
+
+		src += tlen;
+		len -= tlen;
+	}
+	if (i & 0x1)
+		tx_desc->flags |= HSDMA_DESC_LS0;
+	else
+		tx_desc->flags |= HSDMA_DESC_LS1;
+
+	/* rx desc */
+	rx_idx = HSDMA_NEXT_DESC(chan->rx_idx);
+	len = sg->len;
+	dst = sg->dst_addr;
+	for (i = 0; i < chan->desc->num_sgs; i++) {
+		rx_desc = &chan->rx_ring[rx_idx];
+		if (len > HSDMA_MAX_PLEN)
+			tlen = HSDMA_MAX_PLEN;
+		else
+			tlen = len;
+
+		rx_desc->addr0 = dst;
+		rx_desc->flags = HSDMA_DESC_PLEN0(tlen);
+
+		dst += tlen;
+		len -= tlen;
+
+		/* update index */
+		rx_idx = HSDMA_NEXT_DESC(rx_idx);
+	}
+
+	/* make sure desc and index all up to date */
+	wmb();
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CTX, chan->tx_idx);
+
+	return 0;
+}
+
+static int gdma_next_desc(struct mtk_hsdma_chan *chan)
+{
+	struct virt_dma_desc *vdesc;
+
+	vdesc = vchan_next_desc(&chan->vchan);
+	if (!vdesc) {
+		chan->desc = NULL;
+		return 0;
+	}
+	chan->desc = to_mtk_hsdma_desc(vdesc);
+	chan->next_sg = 0;
+
+	return 1;
+}
+
+static void mtk_hsdma_chan_done(struct mtk_hsdam_engine *hsdma,
+				struct mtk_hsdma_chan *chan)
+{
+	struct mtk_hsdma_desc *desc;
+	int chan_issued;
+
+	chan_issued = 0;
+	spin_lock_bh(&chan->vchan.lock);
+	desc = chan->desc;
+	if (likely(desc)) {
+		if (chan->next_sg == desc->num_sgs) {
+			list_del(&desc->vdesc.node);
+			vchan_cookie_complete(&desc->vdesc);
+			chan_issued = gdma_next_desc(chan);
+		}
+	} else
+		dev_dbg(hsdma->ddev.dev, "no desc to complete\n");
+
+	if (chan_issued)
+		set_bit(chan->id, &hsdma->chan_issued);
+	spin_unlock_bh(&chan->vchan.lock);
+}
+
+static irqreturn_t mtk_hsdma_irq(int irq, void *devid)
+{
+	struct mtk_hsdam_engine *hsdma = devid;
+	u32 status;
+
+	status = mtk_hsdma_read(hsdma, HSDMA_REG_INT_STATUS);
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	if (likely(status & HSDMA_INT_RX_Q0))
+		tasklet_schedule(&hsdma->task);
+	else
+		dev_dbg(hsdma->ddev.dev, "unhandle irq status %08x\n",
+			status);
+	/* clean intr bits */
+	mtk_hsdma_write(hsdma, HSDMA_REG_INT_STATUS, status);
+
+	return IRQ_HANDLED;
+}
+
+static void mtk_hsdma_issue_pending(struct dma_chan *c)
+{
+	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
+	struct mtk_hsdam_engine *hsdma = mtk_hsdma_chan_get_dev(chan);
+
+	spin_lock_bh(&chan->vchan.lock);
+	if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
+		if (gdma_next_desc(chan)) {
+			set_bit(chan->id, &hsdma->chan_issued);
+			tasklet_schedule(&hsdma->task);
+		} else
+			dev_dbg(hsdma->ddev.dev, "no desc to issue\n");
+	}
+	spin_unlock_bh(&chan->vchan.lock);
+}
+
+static struct dma_async_tx_descriptor *mtk_hsdma_prep_dma_memcpy(
+		struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
+		size_t len, unsigned long flags)
+{
+	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
+	struct mtk_hsdma_desc *desc;
+
+	if (len <= 0)
+		return NULL;
+
+	desc = kzalloc(sizeof(struct mtk_hsdma_desc), GFP_ATOMIC);
+	if (!desc) {
+		dev_err(c->device->dev, "alloc memcpy decs error\n");
+		return NULL;
+	}
+
+	desc->sg[0].src_addr = src;
+	desc->sg[0].dst_addr = dest;
+	desc->sg[0].len = len;
+
+	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
+static enum dma_status mtk_hsdma_tx_status(struct dma_chan *c,
+					   dma_cookie_t cookie,
+					   struct dma_tx_state *state)
+{
+	return dma_cookie_status(c, cookie, state);
+}
+
+static void mtk_hsdma_free_chan_resources(struct dma_chan *c)
+{
+	vchan_free_chan_resources(to_virt_chan(c));
+}
+
+static void mtk_hsdma_desc_free(struct virt_dma_desc *vdesc)
+{
+	kfree(container_of(vdesc, struct mtk_hsdma_desc, vdesc));
+}
+
+static void mtk_hsdma_tx(struct mtk_hsdam_engine *hsdma)
+{
+	struct mtk_hsdma_chan *chan;
+
+	if (test_and_clear_bit(0, &hsdma->chan_issued)) {
+		chan = &hsdma->chan[0];
+		if (chan->desc)
+			mtk_hsdma_start_transfer(hsdma, chan);
+		else
+			dev_dbg(hsdma->ddev.dev, "chan 0 no desc to issue\n");
+	}
+}
+
+static void mtk_hsdma_rx(struct mtk_hsdam_engine *hsdma)
+{
+	struct mtk_hsdma_chan *chan;
+	int next_idx, drx_idx, cnt;
+
+	chan = &hsdma->chan[0];
+	next_idx = HSDMA_NEXT_DESC(chan->rx_idx);
+	drx_idx = mtk_hsdma_read(hsdma, HSDMA_REG_RX_DRX);
+
+	cnt = (drx_idx - next_idx) & HSDMA_DESCS_MASK;
+	if (!cnt)
+		return;
+
+	chan->next_sg += cnt;
+	chan->rx_idx = (chan->rx_idx + cnt) & HSDMA_DESCS_MASK;
+
+	/* update rx crx */
+	wmb();
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CRX, chan->rx_idx);
+
+	mtk_hsdma_chan_done(hsdma, chan);
+}
+
+static void mtk_hsdma_tasklet(unsigned long arg)
+{
+	struct mtk_hsdam_engine *hsdma = (struct mtk_hsdam_engine *)arg;
+
+	mtk_hsdma_rx(hsdma);
+	mtk_hsdma_tx(hsdma);
+}
+
+static int mtk_hsdam_alloc_desc(struct mtk_hsdam_engine *hsdma,
+				struct mtk_hsdma_chan *chan)
+{
+	int i;
+
+	chan->tx_ring = dma_alloc_coherent(hsdma->ddev.dev,
+			2 * HSDMA_DESCS_NUM * sizeof(*chan->tx_ring),
+			&chan->desc_addr, GFP_ATOMIC | __GFP_ZERO);
+	if (!chan->tx_ring)
+		goto no_mem;
+
+	chan->rx_ring = &chan->tx_ring[HSDMA_DESCS_NUM];
+
+	/* init tx ring value */
+	for (i = 0; i < HSDMA_DESCS_NUM; i++)
+		chan->tx_ring[i].flags = HSDMA_DESC_LS0 | HSDMA_DESC_DONE;
+
+	return 0;
+no_mem:
+	return -ENOMEM;
+}
+
+static void mtk_hsdam_free_desc(struct mtk_hsdam_engine *hsdma,
+				struct mtk_hsdma_chan *chan)
+{
+	if (chan->tx_ring) {
+		dma_free_coherent(hsdma->ddev.dev,
+				2 * HSDMA_DESCS_NUM * sizeof(*chan->tx_ring),
+				chan->tx_ring, chan->desc_addr);
+		chan->tx_ring = NULL;
+		chan->rx_ring = NULL;
+	}
+}
+
+static int mtk_hsdma_init(struct mtk_hsdam_engine *hsdma)
+{
+	struct mtk_hsdma_chan *chan;
+	int ret;
+	u32 reg;
+
+	/* init desc */
+	chan = &hsdma->chan[0];
+	ret = mtk_hsdam_alloc_desc(hsdma, chan);
+	if (ret)
+		return ret;
+
+	/* tx */
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_BASE, chan->desc_addr);
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CNT, HSDMA_DESCS_NUM);
+	/* rx */
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_BASE, chan->desc_addr +
+			(sizeof(struct hsdma_desc) * HSDMA_DESCS_NUM));
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CNT, HSDMA_DESCS_NUM);
+	/* reset */
+	mtk_hsdma_reset_chan(hsdma, chan);
+
+	/* enable rx intr */
+	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, HSDMA_INT_RX_Q0);
+
+	/* enable dma */
+	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, HSDMA_GLO_DEFAULT);
+
+	/* hardware info */
+	reg = mtk_hsdma_read(hsdma, HSDMA_REG_INFO);
+	dev_info(hsdma->ddev.dev, "rx: %d, tx: %d\n",
+		 (reg >> HSDMA_INFO_RX_SHIFT) & HSDMA_INFO_RX_MASK,
+		 (reg >> HSDMA_INFO_TX_SHIFT) & HSDMA_INFO_TX_MASK);
+
+	hsdma_dump_reg(hsdma);
+
+	return ret;
+}
+
+static void mtk_hsdma_uninit(struct mtk_hsdam_engine *hsdma)
+{
+	struct mtk_hsdma_chan *chan;
+
+	/* disable dma */
+	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, 0);
+
+	/* disable intr */
+	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, 0);
+
+	/* free desc */
+	chan = &hsdma->chan[0];
+	mtk_hsdam_free_desc(hsdma, chan);
+
+	/* tx */
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_BASE, 0);
+	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CNT, 0);
+	/* rx */
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_BASE, 0);
+	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CNT, 0);
+	/* reset */
+	mtk_hsdma_reset_chan(hsdma, chan);
+}
+
+static const struct of_device_id mtk_hsdma_of_match[] = {
+	{ .compatible = "mediatek,mt7621-hsdma" },
+	{ },
+};
+
+static int mtk_hsdma_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct mtk_hsdma_chan *chan;
+	struct mtk_hsdam_engine *hsdma;
+	struct dma_device *dd;
+	struct resource *res;
+	int ret;
+	int irq;
+	void __iomem *base;
+
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+	if (ret)
+		return ret;
+
+	match = of_match_device(mtk_hsdma_of_match, &pdev->dev);
+	if (!match)
+		return -EINVAL;
+
+	hsdma = devm_kzalloc(&pdev->dev, sizeof(*hsdma), GFP_KERNEL);
+	if (!hsdma) {
+		dev_err(&pdev->dev, "alloc dma device failed\n");
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	hsdma->base = base + HSDMA_BASE_OFFSET;
+	tasklet_init(&hsdma->task, mtk_hsdma_tasklet, (unsigned long)hsdma);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to get irq\n");
+		return -EINVAL;
+	}
+	ret = devm_request_irq(&pdev->dev, irq, mtk_hsdma_irq,
+			       0, dev_name(&pdev->dev), hsdma);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request irq\n");
+		return ret;
+	}
+
+	device_reset(&pdev->dev);
+
+	dd = &hsdma->ddev;
+	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
+	dd->copy_align = HSDMA_ALIGN_SIZE;
+	dd->device_free_chan_resources = mtk_hsdma_free_chan_resources;
+	dd->device_prep_dma_memcpy = mtk_hsdma_prep_dma_memcpy;
+	dd->device_terminate_all = mtk_hsdma_terminate_all;
+	dd->device_tx_status = mtk_hsdma_tx_status;
+	dd->device_issue_pending = mtk_hsdma_issue_pending;
+	dd->dev = &pdev->dev;
+	dd->dev->dma_parms = &hsdma->dma_parms;
+	dma_set_max_seg_size(dd->dev, HSDMA_MAX_PLEN);
+	INIT_LIST_HEAD(&dd->channels);
+
+	chan = &hsdma->chan[0];
+	chan->id = 0;
+	chan->vchan.desc_free = mtk_hsdma_desc_free;
+	vchan_init(&chan->vchan, dd);
+
+	/* init hardware */
+	ret = mtk_hsdma_init(hsdma);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to alloc ring descs\n");
+		return ret;
+	}
+
+	ret = dma_async_device_register(dd);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register dma device\n");
+		goto err_uninit_hsdma;
+	}
+
+	ret = of_dma_controller_register(pdev->dev.of_node,
+					 of_dma_xlate_by_chan_id, hsdma);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register of dma controller\n");
+		goto err_unregister;
+	}
+
+	platform_set_drvdata(pdev, hsdma);
+
+	return 0;
+
+err_unregister:
+	dma_async_device_unregister(dd);
+err_uninit_hsdma:
+	mtk_hsdma_uninit(hsdma);
+	return ret;
+}
+
+static int mtk_hsdma_remove(struct platform_device *pdev)
+{
+	struct mtk_hsdam_engine *hsdma = platform_get_drvdata(pdev);
+
+	mtk_hsdma_uninit(hsdma);
+
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&hsdma->ddev);
+
+	return 0;
+}
+
+static struct platform_driver mtk_hsdma_driver = {
+	.probe = mtk_hsdma_probe,
+	.remove = mtk_hsdma_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = mtk_hsdma_of_match,
+	},
+};
+module_platform_driver(mtk_hsdma_driver);
+
+MODULE_AUTHOR("Michael Lee <igvtee@gmail.com>");
+MODULE_DESCRIPTION("MTK HSDMA driver");
+MODULE_LICENSE("GPL v2");
--- a/drivers/staging/mt7621-dma/mtk-hsdma.c
+++ /dev/null
@@ -1,771 +0,0 @@
-/*
- *  Copyright (C) 2015, Michael Lee <igvtee@gmail.com>
- *  MTK HSDMA support
- *
- *  This program 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.
- *
- */
-
-#include <linux/dmaengine.h>
-#include <linux/dma-mapping.h>
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/list.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/irq.h>
-#include <linux/of_dma.h>
-#include <linux/reset.h>
-#include <linux/of_device.h>
-
-#include "virt-dma.h"
-
-#define HSDMA_BASE_OFFSET		0x800
-
-#define HSDMA_REG_TX_BASE		0x00
-#define HSDMA_REG_TX_CNT		0x04
-#define HSDMA_REG_TX_CTX		0x08
-#define HSDMA_REG_TX_DTX		0x0c
-#define HSDMA_REG_RX_BASE		0x100
-#define HSDMA_REG_RX_CNT		0x104
-#define HSDMA_REG_RX_CRX		0x108
-#define HSDMA_REG_RX_DRX		0x10c
-#define HSDMA_REG_INFO			0x200
-#define HSDMA_REG_GLO_CFG		0x204
-#define HSDMA_REG_RST_CFG		0x208
-#define HSDMA_REG_DELAY_INT		0x20c
-#define HSDMA_REG_FREEQ_THRES		0x210
-#define HSDMA_REG_INT_STATUS		0x220
-#define HSDMA_REG_INT_MASK		0x228
-#define HSDMA_REG_SCH_Q01		0x280
-#define HSDMA_REG_SCH_Q23		0x284
-
-#define HSDMA_DESCS_MAX			0xfff
-#define HSDMA_DESCS_NUM			8
-#define HSDMA_DESCS_MASK		(HSDMA_DESCS_NUM - 1)
-#define HSDMA_NEXT_DESC(x)		(((x) + 1) & HSDMA_DESCS_MASK)
-
-/* HSDMA_REG_INFO */
-#define HSDMA_INFO_INDEX_MASK		0xf
-#define HSDMA_INFO_INDEX_SHIFT		24
-#define HSDMA_INFO_BASE_MASK		0xff
-#define HSDMA_INFO_BASE_SHIFT		16
-#define HSDMA_INFO_RX_MASK		0xff
-#define HSDMA_INFO_RX_SHIFT		8
-#define HSDMA_INFO_TX_MASK		0xff
-#define HSDMA_INFO_TX_SHIFT		0
-
-/* HSDMA_REG_GLO_CFG */
-#define HSDMA_GLO_TX_2B_OFFSET		BIT(31)
-#define HSDMA_GLO_CLK_GATE		BIT(30)
-#define HSDMA_GLO_BYTE_SWAP		BIT(29)
-#define HSDMA_GLO_MULTI_DMA		BIT(10)
-#define HSDMA_GLO_TWO_BUF		BIT(9)
-#define HSDMA_GLO_32B_DESC		BIT(8)
-#define HSDMA_GLO_BIG_ENDIAN		BIT(7)
-#define HSDMA_GLO_TX_DONE		BIT(6)
-#define HSDMA_GLO_BT_MASK		0x3
-#define HSDMA_GLO_BT_SHIFT		4
-#define HSDMA_GLO_RX_BUSY		BIT(3)
-#define HSDMA_GLO_RX_DMA		BIT(2)
-#define HSDMA_GLO_TX_BUSY		BIT(1)
-#define HSDMA_GLO_TX_DMA		BIT(0)
-
-#define HSDMA_BT_SIZE_16BYTES		(0 << HSDMA_GLO_BT_SHIFT)
-#define HSDMA_BT_SIZE_32BYTES		(1 << HSDMA_GLO_BT_SHIFT)
-#define HSDMA_BT_SIZE_64BYTES		(2 << HSDMA_GLO_BT_SHIFT)
-#define HSDMA_BT_SIZE_128BYTES		(3 << HSDMA_GLO_BT_SHIFT)
-
-#define HSDMA_GLO_DEFAULT		(HSDMA_GLO_MULTI_DMA | \
-		HSDMA_GLO_RX_DMA | HSDMA_GLO_TX_DMA | HSDMA_BT_SIZE_32BYTES)
-
-/* HSDMA_REG_RST_CFG */
-#define HSDMA_RST_RX_SHIFT		16
-#define HSDMA_RST_TX_SHIFT		0
-
-/* HSDMA_REG_DELAY_INT */
-#define HSDMA_DELAY_INT_EN		BIT(15)
-#define HSDMA_DELAY_PEND_OFFSET		8
-#define HSDMA_DELAY_TIME_OFFSET		0
-#define HSDMA_DELAY_TX_OFFSET		16
-#define HSDMA_DELAY_RX_OFFSET		0
-
-#define HSDMA_DELAY_INIT(x)		(HSDMA_DELAY_INT_EN | \
-		((x) << HSDMA_DELAY_PEND_OFFSET))
-#define HSDMA_DELAY(x)			((HSDMA_DELAY_INIT(x) << \
-		HSDMA_DELAY_TX_OFFSET) | HSDMA_DELAY_INIT(x))
-
-/* HSDMA_REG_INT_STATUS */
-#define HSDMA_INT_DELAY_RX_COH		BIT(31)
-#define HSDMA_INT_DELAY_RX_INT		BIT(30)
-#define HSDMA_INT_DELAY_TX_COH		BIT(29)
-#define HSDMA_INT_DELAY_TX_INT		BIT(28)
-#define HSDMA_INT_RX_MASK		0x3
-#define HSDMA_INT_RX_SHIFT		16
-#define HSDMA_INT_RX_Q0			BIT(16)
-#define HSDMA_INT_TX_MASK		0xf
-#define HSDMA_INT_TX_SHIFT		0
-#define HSDMA_INT_TX_Q0			BIT(0)
-
-/* tx/rx dma desc flags */
-#define HSDMA_PLEN_MASK			0x3fff
-#define HSDMA_DESC_DONE			BIT(31)
-#define HSDMA_DESC_LS0			BIT(30)
-#define HSDMA_DESC_PLEN0(_x)		(((_x) & HSDMA_PLEN_MASK) << 16)
-#define HSDMA_DESC_TAG			BIT(15)
-#define HSDMA_DESC_LS1			BIT(14)
-#define HSDMA_DESC_PLEN1(_x)		((_x) & HSDMA_PLEN_MASK)
-
-/* align 4 bytes */
-#define HSDMA_ALIGN_SIZE		3
-/* align size 128bytes */
-#define HSDMA_MAX_PLEN			0x3f80
-
-struct hsdma_desc {
-	u32 addr0;
-	u32 flags;
-	u32 addr1;
-	u32 unused;
-};
-
-struct mtk_hsdma_sg {
-	dma_addr_t src_addr;
-	dma_addr_t dst_addr;
-	u32 len;
-};
-
-struct mtk_hsdma_desc {
-	struct virt_dma_desc vdesc;
-	unsigned int num_sgs;
-	struct mtk_hsdma_sg sg[1];
-};
-
-struct mtk_hsdma_chan {
-	struct virt_dma_chan vchan;
-	unsigned int id;
-	dma_addr_t desc_addr;
-	int tx_idx;
-	int rx_idx;
-	struct hsdma_desc *tx_ring;
-	struct hsdma_desc *rx_ring;
-	struct mtk_hsdma_desc *desc;
-	unsigned int next_sg;
-};
-
-struct mtk_hsdam_engine {
-	struct dma_device ddev;
-	struct device_dma_parameters dma_parms;
-	void __iomem *base;
-	struct tasklet_struct task;
-	volatile unsigned long chan_issued;
-
-	struct mtk_hsdma_chan chan[1];
-};
-
-static inline struct mtk_hsdam_engine *mtk_hsdma_chan_get_dev(
-		struct mtk_hsdma_chan *chan)
-{
-	return container_of(chan->vchan.chan.device, struct mtk_hsdam_engine,
-			ddev);
-}
-
-static inline struct mtk_hsdma_chan *to_mtk_hsdma_chan(struct dma_chan *c)
-{
-	return container_of(c, struct mtk_hsdma_chan, vchan.chan);
-}
-
-static inline struct mtk_hsdma_desc *to_mtk_hsdma_desc(
-		struct virt_dma_desc *vdesc)
-{
-	return container_of(vdesc, struct mtk_hsdma_desc, vdesc);
-}
-
-static inline u32 mtk_hsdma_read(struct mtk_hsdam_engine *hsdma, u32 reg)
-{
-	return readl(hsdma->base + reg);
-}
-
-static inline void mtk_hsdma_write(struct mtk_hsdam_engine *hsdma,
-				   unsigned reg, u32 val)
-{
-	writel(val, hsdma->base + reg);
-}
-
-static void mtk_hsdma_reset_chan(struct mtk_hsdam_engine *hsdma,
-				 struct mtk_hsdma_chan *chan)
-{
-	chan->tx_idx = 0;
-	chan->rx_idx = HSDMA_DESCS_NUM - 1;
-
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CTX, chan->tx_idx);
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CRX, chan->rx_idx);
-
-	mtk_hsdma_write(hsdma, HSDMA_REG_RST_CFG,
-			0x1 << (chan->id + HSDMA_RST_TX_SHIFT));
-	mtk_hsdma_write(hsdma, HSDMA_REG_RST_CFG,
-			0x1 << (chan->id + HSDMA_RST_RX_SHIFT));
-}
-
-static void hsdma_dump_reg(struct mtk_hsdam_engine *hsdma)
-{
-	dev_dbg(hsdma->ddev.dev, "tbase %08x, tcnt %08x, " \
-			"tctx %08x, tdtx: %08x, rbase %08x, " \
-			"rcnt %08x, rctx %08x, rdtx %08x\n",
-			mtk_hsdma_read(hsdma, HSDMA_REG_TX_BASE),
-			mtk_hsdma_read(hsdma, HSDMA_REG_TX_CNT),
-			mtk_hsdma_read(hsdma, HSDMA_REG_TX_CTX),
-			mtk_hsdma_read(hsdma, HSDMA_REG_TX_DTX),
-			mtk_hsdma_read(hsdma, HSDMA_REG_RX_BASE),
-			mtk_hsdma_read(hsdma, HSDMA_REG_RX_CNT),
-			mtk_hsdma_read(hsdma, HSDMA_REG_RX_CRX),
-			mtk_hsdma_read(hsdma, HSDMA_REG_RX_DRX));
-
-	dev_dbg(hsdma->ddev.dev, "info %08x, glo %08x, delay %08x, " \
-			"intr_stat %08x, intr_mask %08x\n",
-			mtk_hsdma_read(hsdma, HSDMA_REG_INFO),
-			mtk_hsdma_read(hsdma, HSDMA_REG_GLO_CFG),
-			mtk_hsdma_read(hsdma, HSDMA_REG_DELAY_INT),
-			mtk_hsdma_read(hsdma, HSDMA_REG_INT_STATUS),
-			mtk_hsdma_read(hsdma, HSDMA_REG_INT_MASK));
-}
-
-static void hsdma_dump_desc(struct mtk_hsdam_engine *hsdma,
-			    struct mtk_hsdma_chan *chan)
-{
-	struct hsdma_desc *tx_desc;
-	struct hsdma_desc *rx_desc;
-	int i;
-
-	dev_dbg(hsdma->ddev.dev, "tx idx: %d, rx idx: %d\n",
-			chan->tx_idx, chan->rx_idx);
-
-	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
-		tx_desc = &chan->tx_ring[i];
-		rx_desc = &chan->rx_ring[i];
-
-		dev_dbg(hsdma->ddev.dev, "%d tx addr0: %08x, flags %08x, " \
-				"tx addr1: %08x, rx addr0 %08x, flags %08x\n",
-				i, tx_desc->addr0, tx_desc->flags, \
-				tx_desc->addr1, rx_desc->addr0, rx_desc->flags);
-	}
-}
-
-static void mtk_hsdma_reset(struct mtk_hsdam_engine *hsdma,
-			    struct mtk_hsdma_chan *chan)
-{
-	int i;
-
-	/* disable dma */
-	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, 0);
-
-	/* disable intr */
-	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, 0);
-
-	/* init desc value */
-	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
-		chan->tx_ring[i].addr0 = 0;
-		chan->tx_ring[i].flags = HSDMA_DESC_LS0 |
-			HSDMA_DESC_DONE;
-	}
-	for (i = 0; i < HSDMA_DESCS_NUM; i++) {
-		chan->rx_ring[i].addr0 = 0;
-		chan->rx_ring[i].flags = 0;
-	}
-
-	/* reset */
-	mtk_hsdma_reset_chan(hsdma, chan);
-
-	/* enable intr */
-	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, HSDMA_INT_RX_Q0);
-
-	/* enable dma */
-	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, HSDMA_GLO_DEFAULT);
-}
-
-static int mtk_hsdma_terminate_all(struct dma_chan *c)
-{
-	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
-	struct mtk_hsdam_engine *hsdma = mtk_hsdma_chan_get_dev(chan);
-	unsigned long timeout;
-	LIST_HEAD(head);
-
-	spin_lock_bh(&chan->vchan.lock);
-	chan->desc = NULL;
-	clear_bit(chan->id, &hsdma->chan_issued);
-	vchan_get_all_descriptors(&chan->vchan, &head);
-	spin_unlock_bh(&chan->vchan.lock);
-
-	vchan_dma_desc_free_list(&chan->vchan, &head);
-
-	/* wait dma transfer complete */
-	timeout = jiffies + msecs_to_jiffies(2000);
-	while (mtk_hsdma_read(hsdma, HSDMA_REG_GLO_CFG) &
-			(HSDMA_GLO_RX_BUSY | HSDMA_GLO_TX_BUSY)) {
-		if (time_after_eq(jiffies, timeout)) {
-			hsdma_dump_desc(hsdma, chan);
-			mtk_hsdma_reset(hsdma, chan);
-			dev_err(hsdma->ddev.dev, "timeout, reset it\n");
-			break;
-		}
-		cpu_relax();
-	}
-
-	return 0;
-}
-
-static int mtk_hsdma_start_transfer(struct mtk_hsdam_engine *hsdma,
-				    struct mtk_hsdma_chan *chan)
-{
-	dma_addr_t src, dst;
-	size_t len, tlen;
-	struct hsdma_desc *tx_desc, *rx_desc;
-	struct mtk_hsdma_sg *sg;
-	unsigned int i;
-	int rx_idx;
-
-	sg = &chan->desc->sg[0];
-	len = sg->len;
-	chan->desc->num_sgs = DIV_ROUND_UP(len, HSDMA_MAX_PLEN);
-
-	/* tx desc */
-	src = sg->src_addr;
-	for (i = 0; i < chan->desc->num_sgs; i++) {
-		tx_desc = &chan->tx_ring[chan->tx_idx];
-
-		if (len > HSDMA_MAX_PLEN)
-			tlen = HSDMA_MAX_PLEN;
-		else
-			tlen = len;
-
-		if (i & 0x1) {
-			tx_desc->addr1 = src;
-			tx_desc->flags |= HSDMA_DESC_PLEN1(tlen);
-		} else {
-			tx_desc->addr0 = src;
-			tx_desc->flags = HSDMA_DESC_PLEN0(tlen);
-
-			/* update index */
-			chan->tx_idx = HSDMA_NEXT_DESC(chan->tx_idx);
-		}
-
-		src += tlen;
-		len -= tlen;
-	}
-	if (i & 0x1)
-		tx_desc->flags |= HSDMA_DESC_LS0;
-	else
-		tx_desc->flags |= HSDMA_DESC_LS1;
-
-	/* rx desc */
-	rx_idx = HSDMA_NEXT_DESC(chan->rx_idx);
-	len = sg->len;
-	dst = sg->dst_addr;
-	for (i = 0; i < chan->desc->num_sgs; i++) {
-		rx_desc = &chan->rx_ring[rx_idx];
-		if (len > HSDMA_MAX_PLEN)
-			tlen = HSDMA_MAX_PLEN;
-		else
-			tlen = len;
-
-		rx_desc->addr0 = dst;
-		rx_desc->flags = HSDMA_DESC_PLEN0(tlen);
-
-		dst += tlen;
-		len -= tlen;
-
-		/* update index */
-		rx_idx = HSDMA_NEXT_DESC(rx_idx);
-	}
-
-	/* make sure desc and index all up to date */
-	wmb();
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CTX, chan->tx_idx);
-
-	return 0;
-}
-
-static int gdma_next_desc(struct mtk_hsdma_chan *chan)
-{
-	struct virt_dma_desc *vdesc;
-
-	vdesc = vchan_next_desc(&chan->vchan);
-	if (!vdesc) {
-		chan->desc = NULL;
-		return 0;
-	}
-	chan->desc = to_mtk_hsdma_desc(vdesc);
-	chan->next_sg = 0;
-
-	return 1;
-}
-
-static void mtk_hsdma_chan_done(struct mtk_hsdam_engine *hsdma,
-				struct mtk_hsdma_chan *chan)
-{
-	struct mtk_hsdma_desc *desc;
-	int chan_issued;
-
-	chan_issued = 0;
-	spin_lock_bh(&chan->vchan.lock);
-	desc = chan->desc;
-	if (likely(desc)) {
-		if (chan->next_sg == desc->num_sgs) {
-			list_del(&desc->vdesc.node);
-			vchan_cookie_complete(&desc->vdesc);
-			chan_issued = gdma_next_desc(chan);
-		}
-	} else
-		dev_dbg(hsdma->ddev.dev, "no desc to complete\n");
-
-	if (chan_issued)
-		set_bit(chan->id, &hsdma->chan_issued);
-	spin_unlock_bh(&chan->vchan.lock);
-}
-
-static irqreturn_t mtk_hsdma_irq(int irq, void *devid)
-{
-	struct mtk_hsdam_engine *hsdma = devid;
-	u32 status;
-
-	status = mtk_hsdma_read(hsdma, HSDMA_REG_INT_STATUS);
-	if (unlikely(!status))
-		return IRQ_NONE;
-
-	if (likely(status & HSDMA_INT_RX_Q0))
-		tasklet_schedule(&hsdma->task);
-	else
-		dev_dbg(hsdma->ddev.dev, "unhandle irq status %08x\n",
-			status);
-	/* clean intr bits */
-	mtk_hsdma_write(hsdma, HSDMA_REG_INT_STATUS, status);
-
-	return IRQ_HANDLED;
-}
-
-static void mtk_hsdma_issue_pending(struct dma_chan *c)
-{
-	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
-	struct mtk_hsdam_engine *hsdma = mtk_hsdma_chan_get_dev(chan);
-
-	spin_lock_bh(&chan->vchan.lock);
-	if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
-		if (gdma_next_desc(chan)) {
-			set_bit(chan->id, &hsdma->chan_issued);
-			tasklet_schedule(&hsdma->task);
-		} else
-			dev_dbg(hsdma->ddev.dev, "no desc to issue\n");
-	}
-	spin_unlock_bh(&chan->vchan.lock);
-}
-
-static struct dma_async_tx_descriptor *mtk_hsdma_prep_dma_memcpy(
-		struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
-		size_t len, unsigned long flags)
-{
-	struct mtk_hsdma_chan *chan = to_mtk_hsdma_chan(c);
-	struct mtk_hsdma_desc *desc;
-
-	if (len <= 0)
-		return NULL;
-
-	desc = kzalloc(sizeof(struct mtk_hsdma_desc), GFP_ATOMIC);
-	if (!desc) {
-		dev_err(c->device->dev, "alloc memcpy decs error\n");
-		return NULL;
-	}
-
-	desc->sg[0].src_addr = src;
-	desc->sg[0].dst_addr = dest;
-	desc->sg[0].len = len;
-
-	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
-}
-
-static enum dma_status mtk_hsdma_tx_status(struct dma_chan *c,
-					   dma_cookie_t cookie,
-					   struct dma_tx_state *state)
-{
-	return dma_cookie_status(c, cookie, state);
-}
-
-static void mtk_hsdma_free_chan_resources(struct dma_chan *c)
-{
-	vchan_free_chan_resources(to_virt_chan(c));
-}
-
-static void mtk_hsdma_desc_free(struct virt_dma_desc *vdesc)
-{
-	kfree(container_of(vdesc, struct mtk_hsdma_desc, vdesc));
-}
-
-static void mtk_hsdma_tx(struct mtk_hsdam_engine *hsdma)
-{
-	struct mtk_hsdma_chan *chan;
-
-	if (test_and_clear_bit(0, &hsdma->chan_issued)) {
-		chan = &hsdma->chan[0];
-		if (chan->desc)
-			mtk_hsdma_start_transfer(hsdma, chan);
-		else
-			dev_dbg(hsdma->ddev.dev, "chan 0 no desc to issue\n");
-	}
-}
-
-static void mtk_hsdma_rx(struct mtk_hsdam_engine *hsdma)
-{
-	struct mtk_hsdma_chan *chan;
-	int next_idx, drx_idx, cnt;
-
-	chan = &hsdma->chan[0];
-	next_idx = HSDMA_NEXT_DESC(chan->rx_idx);
-	drx_idx = mtk_hsdma_read(hsdma, HSDMA_REG_RX_DRX);
-
-	cnt = (drx_idx - next_idx) & HSDMA_DESCS_MASK;
-	if (!cnt)
-		return;
-
-	chan->next_sg += cnt;
-	chan->rx_idx = (chan->rx_idx + cnt) & HSDMA_DESCS_MASK;
-
-	/* update rx crx */
-	wmb();
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CRX, chan->rx_idx);
-
-	mtk_hsdma_chan_done(hsdma, chan);
-}
-
-static void mtk_hsdma_tasklet(unsigned long arg)
-{
-	struct mtk_hsdam_engine *hsdma = (struct mtk_hsdam_engine *)arg;
-
-	mtk_hsdma_rx(hsdma);
-	mtk_hsdma_tx(hsdma);
-}
-
-static int mtk_hsdam_alloc_desc(struct mtk_hsdam_engine *hsdma,
-				struct mtk_hsdma_chan *chan)
-{
-	int i;
-
-	chan->tx_ring = dma_alloc_coherent(hsdma->ddev.dev,
-			2 * HSDMA_DESCS_NUM * sizeof(*chan->tx_ring),
-			&chan->desc_addr, GFP_ATOMIC | __GFP_ZERO);
-	if (!chan->tx_ring)
-		goto no_mem;
-
-	chan->rx_ring = &chan->tx_ring[HSDMA_DESCS_NUM];
-
-	/* init tx ring value */
-	for (i = 0; i < HSDMA_DESCS_NUM; i++)
-		chan->tx_ring[i].flags = HSDMA_DESC_LS0 | HSDMA_DESC_DONE;
-
-	return 0;
-no_mem:
-	return -ENOMEM;
-}
-
-static void mtk_hsdam_free_desc(struct mtk_hsdam_engine *hsdma,
-				struct mtk_hsdma_chan *chan)
-{
-	if (chan->tx_ring) {
-		dma_free_coherent(hsdma->ddev.dev,
-				2 * HSDMA_DESCS_NUM * sizeof(*chan->tx_ring),
-				chan->tx_ring, chan->desc_addr);
-		chan->tx_ring = NULL;
-		chan->rx_ring = NULL;
-	}
-}
-
-static int mtk_hsdma_init(struct mtk_hsdam_engine *hsdma)
-{
-	struct mtk_hsdma_chan *chan;
-	int ret;
-	u32 reg;
-
-	/* init desc */
-	chan = &hsdma->chan[0];
-	ret = mtk_hsdam_alloc_desc(hsdma, chan);
-	if (ret)
-		return ret;
-
-	/* tx */
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_BASE, chan->desc_addr);
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CNT, HSDMA_DESCS_NUM);
-	/* rx */
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_BASE, chan->desc_addr +
-			(sizeof(struct hsdma_desc) * HSDMA_DESCS_NUM));
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CNT, HSDMA_DESCS_NUM);
-	/* reset */
-	mtk_hsdma_reset_chan(hsdma, chan);
-
-	/* enable rx intr */
-	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, HSDMA_INT_RX_Q0);
-
-	/* enable dma */
-	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, HSDMA_GLO_DEFAULT);
-
-	/* hardware info */
-	reg = mtk_hsdma_read(hsdma, HSDMA_REG_INFO);
-	dev_info(hsdma->ddev.dev, "rx: %d, tx: %d\n",
-		 (reg >> HSDMA_INFO_RX_SHIFT) & HSDMA_INFO_RX_MASK,
-		 (reg >> HSDMA_INFO_TX_SHIFT) & HSDMA_INFO_TX_MASK);
-
-	hsdma_dump_reg(hsdma);
-
-	return ret;
-}
-
-static void mtk_hsdma_uninit(struct mtk_hsdam_engine *hsdma)
-{
-	struct mtk_hsdma_chan *chan;
-
-	/* disable dma */
-	mtk_hsdma_write(hsdma, HSDMA_REG_GLO_CFG, 0);
-
-	/* disable intr */
-	mtk_hsdma_write(hsdma, HSDMA_REG_INT_MASK, 0);
-
-	/* free desc */
-	chan = &hsdma->chan[0];
-	mtk_hsdam_free_desc(hsdma, chan);
-
-	/* tx */
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_BASE, 0);
-	mtk_hsdma_write(hsdma, HSDMA_REG_TX_CNT, 0);
-	/* rx */
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_BASE, 0);
-	mtk_hsdma_write(hsdma, HSDMA_REG_RX_CNT, 0);
-	/* reset */
-	mtk_hsdma_reset_chan(hsdma, chan);
-}
-
-static const struct of_device_id mtk_hsdma_of_match[] = {
-	{ .compatible = "mediatek,mt7621-hsdma" },
-	{ },
-};
-
-static int mtk_hsdma_probe(struct platform_device *pdev)
-{
-	const struct of_device_id *match;
-	struct mtk_hsdma_chan *chan;
-	struct mtk_hsdam_engine *hsdma;
-	struct dma_device *dd;
-	struct resource *res;
-	int ret;
-	int irq;
-	void __iomem *base;
-
-	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-	if (ret)
-		return ret;
-
-	match = of_match_device(mtk_hsdma_of_match, &pdev->dev);
-	if (!match)
-		return -EINVAL;
-
-	hsdma = devm_kzalloc(&pdev->dev, sizeof(*hsdma), GFP_KERNEL);
-	if (!hsdma) {
-		dev_err(&pdev->dev, "alloc dma device failed\n");
-		return -EINVAL;
-	}
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(base))
-		return PTR_ERR(base);
-	hsdma->base = base + HSDMA_BASE_OFFSET;
-	tasklet_init(&hsdma->task, mtk_hsdma_tasklet, (unsigned long)hsdma);
-
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(&pdev->dev, "failed to get irq\n");
-		return -EINVAL;
-	}
-	ret = devm_request_irq(&pdev->dev, irq, mtk_hsdma_irq,
-			       0, dev_name(&pdev->dev), hsdma);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to request irq\n");
-		return ret;
-	}
-
-	device_reset(&pdev->dev);
-
-	dd = &hsdma->ddev;
-	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
-	dd->copy_align = HSDMA_ALIGN_SIZE;
-	dd->device_free_chan_resources = mtk_hsdma_free_chan_resources;
-	dd->device_prep_dma_memcpy = mtk_hsdma_prep_dma_memcpy;
-	dd->device_terminate_all = mtk_hsdma_terminate_all;
-	dd->device_tx_status = mtk_hsdma_tx_status;
-	dd->device_issue_pending = mtk_hsdma_issue_pending;
-	dd->dev = &pdev->dev;
-	dd->dev->dma_parms = &hsdma->dma_parms;
-	dma_set_max_seg_size(dd->dev, HSDMA_MAX_PLEN);
-	INIT_LIST_HEAD(&dd->channels);
-
-	chan = &hsdma->chan[0];
-	chan->id = 0;
-	chan->vchan.desc_free = mtk_hsdma_desc_free;
-	vchan_init(&chan->vchan, dd);
-
-	/* init hardware */
-	ret = mtk_hsdma_init(hsdma);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to alloc ring descs\n");
-		return ret;
-	}
-
-	ret = dma_async_device_register(dd);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to register dma device\n");
-		goto err_uninit_hsdma;
-	}
-
-	ret = of_dma_controller_register(pdev->dev.of_node,
-					 of_dma_xlate_by_chan_id, hsdma);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to register of dma controller\n");
-		goto err_unregister;
-	}
-
-	platform_set_drvdata(pdev, hsdma);
-
-	return 0;
-
-err_unregister:
-	dma_async_device_unregister(dd);
-err_uninit_hsdma:
-	mtk_hsdma_uninit(hsdma);
-	return ret;
-}
-
-static int mtk_hsdma_remove(struct platform_device *pdev)
-{
-	struct mtk_hsdam_engine *hsdma = platform_get_drvdata(pdev);
-
-	mtk_hsdma_uninit(hsdma);
-
-	of_dma_controller_free(pdev->dev.of_node);
-	dma_async_device_unregister(&hsdma->ddev);
-
-	return 0;
-}
-
-static struct platform_driver mtk_hsdma_driver = {
-	.probe = mtk_hsdma_probe,
-	.remove = mtk_hsdma_remove,
-	.driver = {
-		.name = "hsdma-mt7621",
-		.of_match_table = mtk_hsdma_of_match,
-	},
-};
-module_platform_driver(mtk_hsdma_driver);
-
-MODULE_AUTHOR("Michael Lee <igvtee@gmail.com>");
-MODULE_DESCRIPTION("MTK HSDMA driver");
-MODULE_LICENSE("GPL v2");