dmaengine: sprd: Add Spreadtrum DMA driver

This patch adds the DMA controller driver for Spreadtrum SC9860 platform.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 988 insertions, 0 deletions

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
new file mode 100644
index 000000000000..b652071a2096
--- /dev/null
+++ b/drivers/dma/sprd-dma.c
@@ -0,0 +1,988 @@
+/*
+ * Copyright (C) 2017 Spreadtrum Communications Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "virt-dma.h"
+
+#define SPRD_DMA_CHN_REG_OFFSET		0x1000
+#define SPRD_DMA_CHN_REG_LENGTH		0x40
+#define SPRD_DMA_MEMCPY_MIN_SIZE	64
+
+/* DMA global registers definition */
+#define SPRD_DMA_GLB_PAUSE		0x0
+#define SPRD_DMA_GLB_FRAG_WAIT		0x4
+#define SPRD_DMA_GLB_REQ_PEND0_EN	0x8
+#define SPRD_DMA_GLB_REQ_PEND1_EN	0xc
+#define SPRD_DMA_GLB_INT_RAW_STS	0x10
+#define SPRD_DMA_GLB_INT_MSK_STS	0x14
+#define SPRD_DMA_GLB_REQ_STS		0x18
+#define SPRD_DMA_GLB_CHN_EN_STS		0x1c
+#define SPRD_DMA_GLB_DEBUG_STS		0x20
+#define SPRD_DMA_GLB_ARB_SEL_STS	0x24
+#define SPRD_DMA_GLB_REQ_UID(uid)	(0x4 * ((uid) - 1))
+#define SPRD_DMA_GLB_REQ_UID_OFFSET	0x2000
+
+/* DMA channel registers definition */
+#define SPRD_DMA_CHN_PAUSE		0x0
+#define SPRD_DMA_CHN_REQ		0x4
+#define SPRD_DMA_CHN_CFG		0x8
+#define SPRD_DMA_CHN_INTC		0xc
+#define SPRD_DMA_CHN_SRC_ADDR		0x10
+#define SPRD_DMA_CHN_DES_ADDR		0x14
+#define SPRD_DMA_CHN_FRG_LEN		0x18
+#define SPRD_DMA_CHN_BLK_LEN		0x1c
+#define SPRD_DMA_CHN_TRSC_LEN		0x20
+#define SPRD_DMA_CHN_TRSF_STEP		0x24
+#define SPRD_DMA_CHN_WARP_PTR		0x28
+#define SPRD_DMA_CHN_WARP_TO		0x2c
+#define SPRD_DMA_CHN_LLIST_PTR		0x30
+#define SPRD_DMA_CHN_FRAG_STEP		0x34
+#define SPRD_DMA_CHN_SRC_BLK_STEP	0x38
+#define SPRD_DMA_CHN_DES_BLK_STEP	0x3c
+
+/* SPRD_DMA_CHN_INTC register definition */
+#define SPRD_DMA_INT_MASK		GENMASK(4, 0)
+#define SPRD_DMA_INT_CLR_OFFSET		24
+#define SPRD_DMA_FRAG_INT_EN		BIT(0)
+#define SPRD_DMA_BLK_INT_EN		BIT(1)
+#define SPRD_DMA_TRANS_INT_EN		BIT(2)
+#define SPRD_DMA_LIST_INT_EN		BIT(3)
+#define SPRD_DMA_CFG_ERR_INT_EN		BIT(4)
+
+/* SPRD_DMA_CHN_CFG register definition */
+#define SPRD_DMA_CHN_EN			BIT(0)
+#define SPRD_DMA_WAIT_BDONE_OFFSET	24
+#define SPRD_DMA_DONOT_WAIT_BDONE	1
+
+/* SPRD_DMA_CHN_REQ register definition */
+#define SPRD_DMA_REQ_EN			BIT(0)
+
+/* SPRD_DMA_CHN_PAUSE register definition */
+#define SPRD_DMA_PAUSE_EN		BIT(0)
+#define SPRD_DMA_PAUSE_STS		BIT(2)
+#define SPRD_DMA_PAUSE_CNT		0x2000
+
+/* DMA_CHN_WARP_* register definition */
+#define SPRD_DMA_HIGH_ADDR_MASK		GENMASK(31, 28)
+#define SPRD_DMA_LOW_ADDR_MASK		GENMASK(31, 0)
+#define SPRD_DMA_HIGH_ADDR_OFFSET	4
+
+/* SPRD_DMA_CHN_INTC register definition */
+#define SPRD_DMA_FRAG_INT_STS		BIT(16)
+#define SPRD_DMA_BLK_INT_STS		BIT(17)
+#define SPRD_DMA_TRSC_INT_STS		BIT(18)
+#define SPRD_DMA_LIST_INT_STS		BIT(19)
+#define SPRD_DMA_CFGERR_INT_STS		BIT(20)
+#define SPRD_DMA_CHN_INT_STS					\
+	(SPRD_DMA_FRAG_INT_STS | SPRD_DMA_BLK_INT_STS |		\
+	 SPRD_DMA_TRSC_INT_STS | SPRD_DMA_LIST_INT_STS |	\
+	 SPRD_DMA_CFGERR_INT_STS)
+
+/* SPRD_DMA_CHN_FRG_LEN register definition */
+#define SPRD_DMA_SRC_DATAWIDTH_OFFSET	30
+#define SPRD_DMA_DES_DATAWIDTH_OFFSET	28
+#define SPRD_DMA_SWT_MODE_OFFSET	26
+#define SPRD_DMA_REQ_MODE_OFFSET	24
+#define SPRD_DMA_REQ_MODE_MASK		GENMASK(1, 0)
+#define SPRD_DMA_FIX_SEL_OFFSET		21
+#define SPRD_DMA_FIX_EN_OFFSET		20
+#define SPRD_DMA_LLIST_END_OFFSET	19
+#define SPRD_DMA_FRG_LEN_MASK		GENMASK(16, 0)
+
+/* SPRD_DMA_CHN_BLK_LEN register definition */
+#define SPRD_DMA_BLK_LEN_MASK		GENMASK(16, 0)
+
+/* SPRD_DMA_CHN_TRSC_LEN register definition */
+#define SPRD_DMA_TRSC_LEN_MASK		GENMASK(27, 0)
+
+/* SPRD_DMA_CHN_TRSF_STEP register definition */
+#define SPRD_DMA_DEST_TRSF_STEP_OFFSET	16
+#define SPRD_DMA_SRC_TRSF_STEP_OFFSET	0
+#define SPRD_DMA_TRSF_STEP_MASK		GENMASK(15, 0)
+
+#define SPRD_DMA_SOFTWARE_UID		0
+
+/*
+ * enum sprd_dma_req_mode: define the DMA request mode
+ * @SPRD_DMA_FRAG_REQ: fragment request mode
+ * @SPRD_DMA_BLK_REQ: block request mode
+ * @SPRD_DMA_TRANS_REQ: transaction request mode
+ * @SPRD_DMA_LIST_REQ: link-list request mode
+ *
+ * We have 4 types request mode: fragment mode, block mode, transaction mode
+ * and linklist mode. One transaction can contain several blocks, one block can
+ * contain several fragments. Link-list mode means we can save several DMA
+ * configuration into one reserved memory, then DMA can fetch each DMA
+ * configuration automatically to start transfer.
+ */
+enum sprd_dma_req_mode {
+	SPRD_DMA_FRAG_REQ,
+	SPRD_DMA_BLK_REQ,
+	SPRD_DMA_TRANS_REQ,
+	SPRD_DMA_LIST_REQ,
+};
+
+/*
+ * enum sprd_dma_int_type: define the DMA interrupt type
+ * @SPRD_DMA_NO_INT: do not need generate DMA interrupts.
+ * @SPRD_DMA_FRAG_INT: fragment done interrupt when one fragment request
+ * is done.
+ * @SPRD_DMA_BLK_INT: block done interrupt when one block request is done.
+ * @SPRD_DMA_BLK_FRAG_INT: block and fragment interrupt when one fragment
+ * or one block request is done.
+ * @SPRD_DMA_TRANS_INT: tansaction done interrupt when one transaction
+ * request is done.
+ * @SPRD_DMA_TRANS_FRAG_INT: transaction and fragment interrupt when one
+ * transaction request or fragment request is done.
+ * @SPRD_DMA_TRANS_BLK_INT: transaction and block interrupt when one
+ * transaction request or block request is done.
+ * @SPRD_DMA_LIST_INT: link-list done interrupt when one link-list request
+ * is done.
+ * @SPRD_DMA_CFGERR_INT: configure error interrupt when configuration is
+ * incorrect.
+ */
+enum sprd_dma_int_type {
+	SPRD_DMA_NO_INT,
+	SPRD_DMA_FRAG_INT,
+	SPRD_DMA_BLK_INT,
+	SPRD_DMA_BLK_FRAG_INT,
+	SPRD_DMA_TRANS_INT,
+	SPRD_DMA_TRANS_FRAG_INT,
+	SPRD_DMA_TRANS_BLK_INT,
+	SPRD_DMA_LIST_INT,
+	SPRD_DMA_CFGERR_INT,
+};
+
+/* dma channel hardware configuration */
+struct sprd_dma_chn_hw {
+	u32 pause;
+	u32 req;
+	u32 cfg;
+	u32 intc;
+	u32 src_addr;
+	u32 des_addr;
+	u32 frg_len;
+	u32 blk_len;
+	u32 trsc_len;
+	u32 trsf_step;
+	u32 wrap_ptr;
+	u32 wrap_to;
+	u32 llist_ptr;
+	u32 frg_step;
+	u32 src_blk_step;
+	u32 des_blk_step;
+};
+
+/* dma request description */
+struct sprd_dma_desc {
+	struct virt_dma_desc	vd;
+	struct sprd_dma_chn_hw	chn_hw;
+};
+
+/* dma channel description */
+struct sprd_dma_chn {
+	struct virt_dma_chan	vc;
+	void __iomem		*chn_base;
+	u32			chn_num;
+	u32			dev_id;
+	struct sprd_dma_desc	*cur_desc;
+};
+
+/* SPRD dma device */
+struct sprd_dma_dev {
+	struct dma_device	dma_dev;
+	void __iomem		*glb_base;
+	struct clk		*clk;
+	struct clk		*ashb_clk;
+	int			irq;
+	u32			total_chns;
+	struct sprd_dma_chn	channels[0];
+};
+
+static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param);
+static struct of_dma_filter_info sprd_dma_info = {
+	.filter_fn = sprd_dma_filter_fn,
+};
+
+static inline struct sprd_dma_chn *to_sprd_dma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct sprd_dma_chn, vc.chan);
+}
+
+static inline struct sprd_dma_dev *to_sprd_dma_dev(struct dma_chan *c)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(c);
+
+	return container_of(schan, struct sprd_dma_dev, channels[c->chan_id]);
+}
+
+static inline struct sprd_dma_desc *to_sprd_dma_desc(struct virt_dma_desc *vd)
+{
+	return container_of(vd, struct sprd_dma_desc, vd);
+}
+
+static void sprd_dma_chn_update(struct sprd_dma_chn *schan, u32 reg,
+				u32 mask, u32 val)
+{
+	u32 orig = readl(schan->chn_base + reg);
+	u32 tmp;
+
+	tmp = (orig & ~mask) | val;
+	writel(tmp, schan->chn_base + reg);
+}
+
+static int sprd_dma_enable(struct sprd_dma_dev *sdev)
+{
+	int ret;
+
+	ret = clk_prepare_enable(sdev->clk);
+	if (ret)
+		return ret;
+
+	/*
+	 * The ashb_clk is optional and only for AGCP DMA controller, so we
+	 * need add one condition to check if the ashb_clk need enable.
+	 */
+	if (!IS_ERR(sdev->ashb_clk))
+		ret = clk_prepare_enable(sdev->ashb_clk);
+
+	return ret;
+}
+
+static void sprd_dma_disable(struct sprd_dma_dev *sdev)
+{
+	clk_disable_unprepare(sdev->clk);
+
+	/*
+	 * Need to check if we need disable the optional ashb_clk for AGCP DMA.
+	 */
+	if (!IS_ERR(sdev->ashb_clk))
+		clk_disable_unprepare(sdev->ashb_clk);
+}
+
+static void sprd_dma_set_uid(struct sprd_dma_chn *schan)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 dev_id = schan->dev_id;
+
+	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
+		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
+				 SPRD_DMA_GLB_REQ_UID(dev_id);
+
+		writel(schan->chn_num + 1, sdev->glb_base + uid_offset);
+	}
+}
+
+static void sprd_dma_unset_uid(struct sprd_dma_chn *schan)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 dev_id = schan->dev_id;
+
+	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
+		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
+				 SPRD_DMA_GLB_REQ_UID(dev_id);
+
+		writel(0, sdev->glb_base + uid_offset);
+	}
+}
+
+static void sprd_dma_clear_int(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_INTC,
+			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET,
+			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET);
+}
+
+static void sprd_dma_enable_chn(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN,
+			    SPRD_DMA_CHN_EN);
+}
+
+static void sprd_dma_disable_chn(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN, 0);
+}
+
+static void sprd_dma_soft_request(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_REQ, SPRD_DMA_REQ_EN,
+			    SPRD_DMA_REQ_EN);
+}
+
+static void sprd_dma_pause_resume(struct sprd_dma_chn *schan, bool enable)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 pause, timeout = SPRD_DMA_PAUSE_CNT;
+
+	if (enable) {
+		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
+				    SPRD_DMA_PAUSE_EN, SPRD_DMA_PAUSE_EN);
+
+		do {
+			pause = readl(schan->chn_base + SPRD_DMA_CHN_PAUSE);
+			if (pause & SPRD_DMA_PAUSE_STS)
+				break;
+
+			cpu_relax();
+		} while (--timeout > 0);
+
+		if (!timeout)
+			dev_warn(sdev->dma_dev.dev,
+				 "pause dma controller timeout\n");
+	} else {
+		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
+				    SPRD_DMA_PAUSE_EN, 0);
+	}
+}
+
+static void sprd_dma_stop_and_disable(struct sprd_dma_chn *schan)
+{
+	u32 cfg = readl(schan->chn_base + SPRD_DMA_CHN_CFG);
+
+	if (!(cfg & SPRD_DMA_CHN_EN))
+		return;
+
+	sprd_dma_pause_resume(schan, true);
+	sprd_dma_disable_chn(schan);
+}
+
+static unsigned long sprd_dma_get_dst_addr(struct sprd_dma_chn *schan)
+{
+	unsigned long addr, addr_high;
+
+	addr = readl(schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
+	addr_high = readl(schan->chn_base + SPRD_DMA_CHN_WARP_TO) &
+		    SPRD_DMA_HIGH_ADDR_MASK;
+
+	return addr | (addr_high << SPRD_DMA_HIGH_ADDR_OFFSET);
+}
+
+static enum sprd_dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *schan)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 intc_sts = readl(schan->chn_base + SPRD_DMA_CHN_INTC) &
+		       SPRD_DMA_CHN_INT_STS;
+
+	switch (intc_sts) {
+	case SPRD_DMA_CFGERR_INT_STS:
+		return SPRD_DMA_CFGERR_INT;
+
+	case SPRD_DMA_LIST_INT_STS:
+		return SPRD_DMA_LIST_INT;
+
+	case SPRD_DMA_TRSC_INT_STS:
+		return SPRD_DMA_TRANS_INT;
+
+	case SPRD_DMA_BLK_INT_STS:
+		return SPRD_DMA_BLK_INT;
+
+	case SPRD_DMA_FRAG_INT_STS:
+		return SPRD_DMA_FRAG_INT;
+
+	default:
+		dev_warn(sdev->dma_dev.dev, "incorrect dma interrupt type\n");
+		return SPRD_DMA_NO_INT;
+	}
+}
+
+static enum sprd_dma_req_mode sprd_dma_get_req_type(struct sprd_dma_chn *schan)
+{
+	u32 frag_reg = readl(schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
+
+	return (frag_reg >> SPRD_DMA_REQ_MODE_OFFSET) & SPRD_DMA_REQ_MODE_MASK;
+}
+
+static void sprd_dma_set_chn_config(struct sprd_dma_chn *schan,
+				    struct sprd_dma_desc *sdesc)
+{
+	struct sprd_dma_chn_hw *cfg = &sdesc->chn_hw;
+
+	writel(cfg->pause, schan->chn_base + SPRD_DMA_CHN_PAUSE);
+	writel(cfg->cfg, schan->chn_base + SPRD_DMA_CHN_CFG);
+	writel(cfg->intc, schan->chn_base + SPRD_DMA_CHN_INTC);
+	writel(cfg->src_addr, schan->chn_base + SPRD_DMA_CHN_SRC_ADDR);
+	writel(cfg->des_addr, schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
+	writel(cfg->frg_len, schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
+	writel(cfg->blk_len, schan->chn_base + SPRD_DMA_CHN_BLK_LEN);
+	writel(cfg->trsc_len, schan->chn_base + SPRD_DMA_CHN_TRSC_LEN);
+	writel(cfg->trsf_step, schan->chn_base + SPRD_DMA_CHN_TRSF_STEP);
+	writel(cfg->wrap_ptr, schan->chn_base + SPRD_DMA_CHN_WARP_PTR);
+	writel(cfg->wrap_to, schan->chn_base + SPRD_DMA_CHN_WARP_TO);
+	writel(cfg->llist_ptr, schan->chn_base + SPRD_DMA_CHN_LLIST_PTR);
+	writel(cfg->frg_step, schan->chn_base + SPRD_DMA_CHN_FRAG_STEP);
+	writel(cfg->src_blk_step, schan->chn_base + SPRD_DMA_CHN_SRC_BLK_STEP);
+	writel(cfg->des_blk_step, schan->chn_base + SPRD_DMA_CHN_DES_BLK_STEP);
+	writel(cfg->req, schan->chn_base + SPRD_DMA_CHN_REQ);
+}
+
+static void sprd_dma_start(struct sprd_dma_chn *schan)
+{
+	struct virt_dma_desc *vd = vchan_next_desc(&schan->vc);
+
+	if (!vd)
+		return;
+
+	list_del(&vd->node);
+	schan->cur_desc = to_sprd_dma_desc(vd);
+
+	/*
+	 * Copy the DMA configuration from DMA descriptor to this hardware
+	 * channel.
+	 */
+	sprd_dma_set_chn_config(schan, schan->cur_desc);
+	sprd_dma_set_uid(schan);
+	sprd_dma_enable_chn(schan);
+
+	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID)
+		sprd_dma_soft_request(schan);
+}
+
+static void sprd_dma_stop(struct sprd_dma_chn *schan)
+{
+	sprd_dma_stop_and_disable(schan);
+	sprd_dma_unset_uid(schan);
+	sprd_dma_clear_int(schan);
+}
+
+static bool sprd_dma_check_trans_done(struct sprd_dma_desc *sdesc,
+				      enum sprd_dma_int_type int_type,
+				      enum sprd_dma_req_mode req_mode)
+{
+	if (int_type == SPRD_DMA_NO_INT)
+		return false;
+
+	if (int_type >= req_mode + 1)
+		return true;
+	else
+		return false;
+}
+
+static irqreturn_t dma_irq_handle(int irq, void *dev_id)
+{
+	struct sprd_dma_dev *sdev = (struct sprd_dma_dev *)dev_id;
+	u32 irq_status = readl(sdev->glb_base + SPRD_DMA_GLB_INT_MSK_STS);
+	struct sprd_dma_chn *schan;
+	struct sprd_dma_desc *sdesc;
+	enum sprd_dma_req_mode req_type;
+	enum sprd_dma_int_type int_type;
+	bool trans_done = false;
+	u32 i;
+
+	while (irq_status) {
+		i = __ffs(irq_status);
+		irq_status &= (irq_status - 1);
+		schan = &sdev->channels[i];
+
+		spin_lock(&schan->vc.lock);
+		int_type = sprd_dma_get_int_type(schan);
+		req_type = sprd_dma_get_req_type(schan);
+		sprd_dma_clear_int(schan);
+
+		sdesc = schan->cur_desc;
+
+		/* Check if the dma request descriptor is done. */
+		trans_done = sprd_dma_check_trans_done(sdesc, int_type,
+						       req_type);
+		if (trans_done == true) {
+			vchan_cookie_complete(&sdesc->vd);
+			schan->cur_desc = NULL;
+			sprd_dma_start(schan);
+		}
+		spin_unlock(&schan->vc.lock);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int sprd_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	int ret;
+
+	ret = pm_runtime_get_sync(chan->device->dev);
+	if (ret < 0)
+		return ret;
+
+	schan->dev_id = SPRD_DMA_SOFTWARE_UID;
+	return 0;
+}
+
+static void sprd_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_stop(schan);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	vchan_free_chan_resources(&schan->vc);
+	pm_runtime_put(chan->device->dev);
+}
+
+static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
+					  dma_cookie_t cookie,
+					  struct dma_tx_state *txstate)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct virt_dma_desc *vd;
+	unsigned long flags;
+	enum dma_status ret;
+	u32 pos;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (ret == DMA_COMPLETE || !txstate)
+		return ret;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	vd = vchan_find_desc(&schan->vc, cookie);
+	if (vd) {
+		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
+		struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+
+		if (hw->trsc_len > 0)
+			pos = hw->trsc_len;
+		else if (hw->blk_len > 0)
+			pos = hw->blk_len;
+		else if (hw->frg_len > 0)
+			pos = hw->frg_len;
+		else
+			pos = 0;
+	} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
+		pos = sprd_dma_get_dst_addr(schan);
+	} else {
+		pos = 0;
+	}
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	dma_set_residue(txstate, pos);
+	return ret;
+}
+
+static void sprd_dma_issue_pending(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	if (vchan_issue_pending(&schan->vc) && !schan->cur_desc)
+		sprd_dma_start(schan);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+}
+
+static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
+			   dma_addr_t dest, dma_addr_t src, size_t len)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
+	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+	u32 datawidth, src_step, des_step, fragment_len;
+	u32 block_len, req_mode, irq_mode, transcation_len;
+	u32 fix_mode = 0, fix_en = 0;
+
+	if (IS_ALIGNED(len, 4)) {
+		datawidth = 2;
+		src_step = 4;
+		des_step = 4;
+	} else if (IS_ALIGNED(len, 2)) {
+		datawidth = 1;
+		src_step = 2;
+		des_step = 2;
+	} else {
+		datawidth = 0;
+		src_step = 1;
+		des_step = 1;
+	}
+
+	fragment_len = SPRD_DMA_MEMCPY_MIN_SIZE;
+	if (len <= SPRD_DMA_BLK_LEN_MASK) {
+		block_len = len;
+		transcation_len = 0;
+		req_mode = SPRD_DMA_BLK_REQ;
+		irq_mode = SPRD_DMA_BLK_INT;
+	} else {
+		block_len = SPRD_DMA_MEMCPY_MIN_SIZE;
+		transcation_len = len;
+		req_mode = SPRD_DMA_TRANS_REQ;
+		irq_mode = SPRD_DMA_TRANS_INT;
+	}
+
+	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
+	hw->wrap_ptr = (u32)((src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+			     SPRD_DMA_HIGH_ADDR_MASK);
+	hw->wrap_to = (u32)((dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+			    SPRD_DMA_HIGH_ADDR_MASK);
+
+	hw->src_addr = (u32)(src & SPRD_DMA_LOW_ADDR_MASK);
+	hw->des_addr = (u32)(dest & SPRD_DMA_LOW_ADDR_MASK);
+
+	if ((src_step != 0 && des_step != 0) || (src_step | des_step) == 0) {
+		fix_en = 0;
+	} else {
+		fix_en = 1;
+		if (src_step)
+			fix_mode = 1;
+		else
+			fix_mode = 0;
+	}
+
+	hw->frg_len = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
+		datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
+		req_mode << SPRD_DMA_REQ_MODE_OFFSET |
+		fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
+		fix_en << SPRD_DMA_FIX_EN_OFFSET |
+		(fragment_len & SPRD_DMA_FRG_LEN_MASK);
+	hw->blk_len = block_len & SPRD_DMA_BLK_LEN_MASK;
+
+	hw->intc = SPRD_DMA_CFG_ERR_INT_EN;
+
+	switch (irq_mode) {
+	case SPRD_DMA_NO_INT:
+		break;
+
+	case SPRD_DMA_FRAG_INT:
+		hw->intc |= SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_BLK_INT:
+		hw->intc |= SPRD_DMA_BLK_INT_EN;
+		break;
+
+	case SPRD_DMA_BLK_FRAG_INT:
+		hw->intc |= SPRD_DMA_BLK_INT_EN | SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_FRAG_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_BLK_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_BLK_INT_EN;
+		break;
+
+	case SPRD_DMA_LIST_INT:
+		hw->intc |= SPRD_DMA_LIST_INT_EN;
+		break;
+
+	case SPRD_DMA_CFGERR_INT:
+		hw->intc |= SPRD_DMA_CFG_ERR_INT_EN;
+		break;
+
+	default:
+		dev_err(sdev->dma_dev.dev, "invalid irq mode\n");
+		return -EINVAL;
+	}
+
+	if (transcation_len == 0)
+		hw->trsc_len = block_len & SPRD_DMA_TRSC_LEN_MASK;
+	else
+		hw->trsc_len = transcation_len & SPRD_DMA_TRSC_LEN_MASK;
+
+	hw->trsf_step = (des_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_DEST_TRSF_STEP_OFFSET |
+			(src_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_SRC_TRSF_STEP_OFFSET;
+
+	hw->frg_step = 0;
+	hw->src_blk_step = 0;
+	hw->des_blk_step = 0;
+	hw->src_blk_step = 0;
+	return 0;
+}
+
+struct dma_async_tx_descriptor *
+sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+			 size_t len, unsigned long flags)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_desc *sdesc;
+	int ret;
+
+	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+	if (!sdesc)
+		return NULL;
+
+	ret = sprd_dma_config(chan, sdesc, dest, src, len);
+	if (ret) {
+		kfree(sdesc);
+		return NULL;
+	}
+
+	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
+}
+
+static int sprd_dma_pause(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_pause_resume(schan, true);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	return 0;
+}
+
+static int sprd_dma_resume(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_pause_resume(schan, false);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	return 0;
+}
+
+static int sprd_dma_terminate_all(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_stop(schan);
+
+	vchan_get_all_descriptors(&schan->vc, &head);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	vchan_dma_desc_free_list(&schan->vc, &head);
+	return 0;
+}
+
+static void sprd_dma_free_desc(struct virt_dma_desc *vd)
+{
+	struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
+
+	kfree(sdesc);
+}
+
+static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 req = *(u32 *)param;
+
+	if (req < sdev->total_chns)
+		return req == schan->chn_num + 1;
+	else
+		return false;
+}
+
+static int sprd_dma_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct sprd_dma_dev *sdev;
+	struct sprd_dma_chn *dma_chn;
+	struct resource *res;
+	u32 chn_count;
+	int ret, i;
+
+	ret = device_property_read_u32(&pdev->dev, "#dma-channels", &chn_count);
+	if (ret) {
+		dev_err(&pdev->dev, "get dma channels count failed\n");
+		return ret;
+	}
+
+	sdev = devm_kzalloc(&pdev->dev, sizeof(*sdev) +
+			    sizeof(*dma_chn) * chn_count,
+			    GFP_KERNEL);
+	if (!sdev)
+		return -ENOMEM;
+
+	sdev->clk = devm_clk_get(&pdev->dev, "enable");
+	if (IS_ERR(sdev->clk)) {
+		dev_err(&pdev->dev, "get enable clock failed\n");
+		return PTR_ERR(sdev->clk);
+	}
+
+	/* ashb clock is optional for AGCP DMA */
+	sdev->ashb_clk = devm_clk_get(&pdev->dev, "ashb_eb");
+	if (IS_ERR(sdev->ashb_clk))
+		dev_warn(&pdev->dev, "no optional ashb eb clock\n");
+
+	/*
+	 * We have three DMA controllers: AP DMA, AON DMA and AGCP DMA. For AGCP
+	 * DMA controller, it can or do not request the irq, which will save
+	 * system power without resuming system by DMA interrupts if AGCP DMA
+	 * does not request the irq. Thus the DMA interrupts property should
+	 * be optional.
+	 */
+	sdev->irq = platform_get_irq(pdev, 0);
+	if (sdev->irq > 0) {
+		ret = devm_request_irq(&pdev->dev, sdev->irq, dma_irq_handle,
+				       0, "sprd_dma", (void *)sdev);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "request dma irq failed\n");
+			return ret;
+		}
+	} else {
+		dev_warn(&pdev->dev, "no interrupts for the dma controller\n");
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sdev->glb_base = devm_ioremap_nocache(&pdev->dev, res->start,
+					      resource_size(res));
+	if (!sdev->glb_base)
+		return -ENOMEM;
+
+	dma_cap_set(DMA_MEMCPY, sdev->dma_dev.cap_mask);
+	sdev->total_chns = chn_count;
+	sdev->dma_dev.chancnt = chn_count;
+	INIT_LIST_HEAD(&sdev->dma_dev.channels);
+	INIT_LIST_HEAD(&sdev->dma_dev.global_node);
+	sdev->dma_dev.dev = &pdev->dev;
+	sdev->dma_dev.device_alloc_chan_resources = sprd_dma_alloc_chan_resources;
+	sdev->dma_dev.device_free_chan_resources = sprd_dma_free_chan_resources;
+	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
+	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
+	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
+	sdev->dma_dev.device_pause = sprd_dma_pause;
+	sdev->dma_dev.device_resume = sprd_dma_resume;
+	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;
+
+	for (i = 0; i < chn_count; i++) {
+		dma_chn = &sdev->channels[i];
+		dma_chn->chn_num = i;
+		dma_chn->cur_desc = NULL;
+		/* get each channel's registers base address. */
+		dma_chn->chn_base = sdev->glb_base + SPRD_DMA_CHN_REG_OFFSET +
+				    SPRD_DMA_CHN_REG_LENGTH * i;
+
+		dma_chn->vc.desc_free = sprd_dma_free_desc;
+		vchan_init(&dma_chn->vc, &sdev->dma_dev);
+	}
+
+	platform_set_drvdata(pdev, sdev);
+	ret = sprd_dma_enable(sdev);
+	if (ret)
+		return ret;
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		goto err_rpm;
+
+	ret = dma_async_device_register(&sdev->dma_dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "register dma device failed:%d\n", ret);
+		goto err_register;
+	}
+
+	sprd_dma_info.dma_cap = sdev->dma_dev.cap_mask;
+	ret = of_dma_controller_register(np, of_dma_simple_xlate,
+					 &sprd_dma_info);
+	if (ret)
+		goto err_of_register;
+
+	pm_runtime_put(&pdev->dev);
+	return 0;
+
+err_of_register:
+	dma_async_device_unregister(&sdev->dma_dev);
+err_register:
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+err_rpm:
+	sprd_dma_disable(sdev);
+	return ret;
+}
+
+static int sprd_dma_remove(struct platform_device *pdev)
+{
+	struct sprd_dma_dev *sdev = platform_get_drvdata(pdev);
+	struct sprd_dma_chn *c, *cn;
+	int ret;
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	/* explicitly free the irq */
+	if (sdev->irq > 0)
+		devm_free_irq(&pdev->dev, sdev->irq, sdev);
+
+	list_for_each_entry_safe(c, cn, &sdev->dma_dev.channels,
+				 vc.chan.device_node) {
+		list_del(&c->vc.chan.device_node);
+		tasklet_kill(&c->vc.task);
+	}
+
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&sdev->dma_dev);
+	sprd_dma_disable(sdev);
+
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	return 0;
+}
+
+static const struct of_device_id sprd_dma_match[] = {
+	{ .compatible = "sprd,sc9860-dma", },
+	{},
+};
+
+static int __maybe_unused sprd_dma_runtime_suspend(struct device *dev)
+{
+	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
+
+	sprd_dma_disable(sdev);
+	return 0;
+}
+
+static int __maybe_unused sprd_dma_runtime_resume(struct device *dev)
+{
+	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = sprd_dma_enable(sdev);
+	if (ret)
+		dev_err(sdev->dma_dev.dev, "enable dma failed\n");
+
+	return ret;
+}
+
+static const struct dev_pm_ops sprd_dma_pm_ops = {
+	SET_RUNTIME_PM_OPS(sprd_dma_runtime_suspend,
+			   sprd_dma_runtime_resume,
+			   NULL)
+};
+
+static struct platform_driver sprd_dma_driver = {
+	.probe = sprd_dma_probe,
+	.remove = sprd_dma_remove,
+	.driver = {
+		.name = "sprd-dma",
+		.of_match_table = sprd_dma_match,
+		.pm = &sprd_dma_pm_ops,
+	},
+};
+module_platform_driver(sprd_dma_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DMA driver for Spreadtrum");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
+MODULE_ALIAS("platform:sprd-dma");