[PATCH 05/13] staging: mt7621-dma: ralink: add rt2880 dma engine
From: NeilBrown
Date: Wed Mar 14 2018 - 16:23:43 EST
From: John Crispin <blogic@xxxxxxxxxxx>
Signed-off-by: John Crispin <blogic@xxxxxxxxxxx>
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
drivers/staging/Kconfig | 2
drivers/staging/Makefile | 1
drivers/staging/mt7621-dma/Kconfig | 12
drivers/staging/mt7621-dma/Makefile | 4
drivers/staging/mt7621-dma/TODO | 5
drivers/staging/mt7621-dma/mtk-hsdma.c | 767 +++++++++++++++++++++++++
drivers/staging/mt7621-dma/ralink-gdma.c | 928 ++++++++++++++++++++++++++++++
7 files changed, 1719 insertions(+)
create mode 100644 drivers/staging/mt7621-dma/Kconfig
create mode 100644 drivers/staging/mt7621-dma/Makefile
create mode 100644 drivers/staging/mt7621-dma/TODO
create mode 100644 drivers/staging/mt7621-dma/mtk-hsdma.c
create mode 100644 drivers/staging/mt7621-dma/ralink-gdma.c
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index bcc6da1f656a..fa8cb95da178 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -128,4 +128,6 @@ source "drivers/staging/mt7621-gpio/Kconfig"
source "drivers/staging/mt7621-spi/Kconfig"
+source "drivers/staging/mt7621-dma/Kconfig"
+
endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 051af9965549..a577f3ac2dd0 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -56,3 +56,4 @@ obj-$(CONFIG_SOC_MT7621) += mt7621-pci/
obj-$(CONFIG_SOC_MT7621) += mt7621-pinctrl/
obj-$(CONFIG_SOC_MT7621) += mt7621-gpio/
obj-$(CONFIG_SOC_MT7621) += mt7621-spi/
+obj-$(CONFIG_SOC_MT7621) += mt7621-dma/
diff --git a/drivers/staging/mt7621-dma/Kconfig b/drivers/staging/mt7621-dma/Kconfig
new file mode 100644
index 000000000000..2423c40099d1
--- /dev/null
+++ b/drivers/staging/mt7621-dma/Kconfig
@@ -0,0 +1,12 @@
+config DMA_RALINK
+ tristate "RALINK DMA support"
+ depends on RALINK && !SOC_RT288X
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+
+config MTK_HSDMA
+ tristate "MTK HSDMA support"
+ depends on RALINK && SOC_MT7621
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+
diff --git a/drivers/staging/mt7621-dma/Makefile b/drivers/staging/mt7621-dma/Makefile
new file mode 100644
index 000000000000..d3152d45cf45
--- /dev/null
+++ b/drivers/staging/mt7621-dma/Makefile
@@ -0,0 +1,4 @@
+obj-$(CONFIG_DMA_RALINK) += ralink-gdma.o
+obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o
+
+ccflags-y += -I$(srctree)/drivers/dma
diff --git a/drivers/staging/mt7621-dma/TODO b/drivers/staging/mt7621-dma/TODO
new file mode 100644
index 000000000000..fdbc5002c32a
--- /dev/null
+++ b/drivers/staging/mt7621-dma/TODO
@@ -0,0 +1,5 @@
+
+- general code review and clean up
+- ensure device-tree requirements are documented
+
+Cc: NeilBrown <neil@xxxxxxxxxx>
diff --git a/drivers/staging/mt7621-dma/mtk-hsdma.c b/drivers/staging/mt7621-dma/mtk-hsdma.c
new file mode 100644
index 000000000000..5eba86e2d566
--- /dev/null
+++ b/drivers/staging/mt7621-dma/mtk-hsdma.c
@@ -0,0 +1,767 @@
+/*
+ * Copyright (C) 2015, Michael Lee <igvtee@xxxxxxxxx>
+ * 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++) {
+ 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 = &chan->tx_ring[chan->tx_idx];
+ 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");
+ return ret;
+ }
+
+ 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);
+ 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@xxxxxxxxx>");
+MODULE_DESCRIPTION("MTK HSDMA driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/mt7621-dma/ralink-gdma.c b/drivers/staging/mt7621-dma/ralink-gdma.c
new file mode 100644
index 000000000000..23ddd64eb1b3
--- /dev/null
+++ b/drivers/staging/mt7621-dma/ralink-gdma.c
@@ -0,0 +1,928 @@
+/*
+ * Copyright (C) 2013, Lars-Peter Clausen <lars@xxxxxxxxxx>
+ * GDMA4740 DMAC 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 GDMA_REG_SRC_ADDR(x) (0x00 + (x) * 0x10)
+#define GDMA_REG_DST_ADDR(x) (0x04 + (x) * 0x10)
+
+#define GDMA_REG_CTRL0(x) (0x08 + (x) * 0x10)
+#define GDMA_REG_CTRL0_TX_MASK 0xffff
+#define GDMA_REG_CTRL0_TX_SHIFT 16
+#define GDMA_REG_CTRL0_CURR_MASK 0xff
+#define GDMA_REG_CTRL0_CURR_SHIFT 8
+#define GDMA_REG_CTRL0_SRC_ADDR_FIXED BIT(7)
+#define GDMA_REG_CTRL0_DST_ADDR_FIXED BIT(6)
+#define GDMA_REG_CTRL0_BURST_MASK 0x7
+#define GDMA_REG_CTRL0_BURST_SHIFT 3
+#define GDMA_REG_CTRL0_DONE_INT BIT(2)
+#define GDMA_REG_CTRL0_ENABLE BIT(1)
+#define GDMA_REG_CTRL0_SW_MODE BIT(0)
+
+#define GDMA_REG_CTRL1(x) (0x0c + (x) * 0x10)
+#define GDMA_REG_CTRL1_SEG_MASK 0xf
+#define GDMA_REG_CTRL1_SEG_SHIFT 22
+#define GDMA_REG_CTRL1_REQ_MASK 0x3f
+#define GDMA_REG_CTRL1_SRC_REQ_SHIFT 16
+#define GDMA_REG_CTRL1_DST_REQ_SHIFT 8
+#define GDMA_REG_CTRL1_CONTINOUS BIT(14)
+#define GDMA_REG_CTRL1_NEXT_MASK 0x1f
+#define GDMA_REG_CTRL1_NEXT_SHIFT 3
+#define GDMA_REG_CTRL1_COHERENT BIT(2)
+#define GDMA_REG_CTRL1_FAIL BIT(1)
+#define GDMA_REG_CTRL1_MASK BIT(0)
+
+#define GDMA_REG_UNMASK_INT 0x200
+#define GDMA_REG_DONE_INT 0x204
+
+#define GDMA_REG_GCT 0x220
+#define GDMA_REG_GCT_CHAN_MASK 0x3
+#define GDMA_REG_GCT_CHAN_SHIFT 3
+#define GDMA_REG_GCT_VER_MASK 0x3
+#define GDMA_REG_GCT_VER_SHIFT 1
+#define GDMA_REG_GCT_ARBIT_RR BIT(0)
+
+#define GDMA_REG_REQSTS 0x2a0
+#define GDMA_REG_ACKSTS 0x2a4
+#define GDMA_REG_FINSTS 0x2a8
+
+/* for RT305X gdma registers */
+#define GDMA_RT305X_CTRL0_REQ_MASK 0xf
+#define GDMA_RT305X_CTRL0_SRC_REQ_SHIFT 12
+#define GDMA_RT305X_CTRL0_DST_REQ_SHIFT 8
+
+#define GDMA_RT305X_CTRL1_FAIL BIT(4)
+#define GDMA_RT305X_CTRL1_NEXT_MASK 0x7
+#define GDMA_RT305X_CTRL1_NEXT_SHIFT 1
+
+#define GDMA_RT305X_STATUS_INT 0x80
+#define GDMA_RT305X_STATUS_SIGNAL 0x84
+#define GDMA_RT305X_GCT 0x88
+
+/* for MT7621 gdma registers */
+#define GDMA_REG_PERF_START(x) (0x230 + (x) * 0x8)
+#define GDMA_REG_PERF_END(x) (0x234 + (x) * 0x8)
+
+enum gdma_dma_transfer_size {
+ GDMA_TRANSFER_SIZE_4BYTE = 0,
+ GDMA_TRANSFER_SIZE_8BYTE = 1,
+ GDMA_TRANSFER_SIZE_16BYTE = 2,
+ GDMA_TRANSFER_SIZE_32BYTE = 3,
+ GDMA_TRANSFER_SIZE_64BYTE = 4,
+};
+
+struct gdma_dma_sg {
+ dma_addr_t src_addr;
+ dma_addr_t dst_addr;
+ u32 len;
+};
+
+struct gdma_dma_desc {
+ struct virt_dma_desc vdesc;
+
+ enum dma_transfer_direction direction;
+ bool cyclic;
+
+ u32 residue;
+ unsigned int num_sgs;
+ struct gdma_dma_sg sg[];
+};
+
+struct gdma_dmaengine_chan {
+ struct virt_dma_chan vchan;
+ unsigned int id;
+ unsigned int slave_id;
+
+ dma_addr_t fifo_addr;
+ enum gdma_dma_transfer_size burst_size;
+
+ struct gdma_dma_desc *desc;
+ unsigned int next_sg;
+};
+
+struct gdma_dma_dev {
+ struct dma_device ddev;
+ struct device_dma_parameters dma_parms;
+ struct gdma_data *data;
+ void __iomem *base;
+ struct tasklet_struct task;
+ volatile unsigned long chan_issued;
+ atomic_t cnt;
+
+ struct gdma_dmaengine_chan chan[];
+};
+
+struct gdma_data
+{
+ int chancnt;
+ u32 done_int_reg;
+ void (*init)(struct gdma_dma_dev *dma_dev);
+ int (*start_transfer)(struct gdma_dmaengine_chan *chan);
+};
+
+static struct gdma_dma_dev *gdma_dma_chan_get_dev(
+ struct gdma_dmaengine_chan *chan)
+{
+ return container_of(chan->vchan.chan.device, struct gdma_dma_dev,
+ ddev);
+}
+
+static struct gdma_dmaengine_chan *to_gdma_dma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct gdma_dmaengine_chan, vchan.chan);
+}
+
+static struct gdma_dma_desc *to_gdma_dma_desc(struct virt_dma_desc *vdesc)
+{
+ return container_of(vdesc, struct gdma_dma_desc, vdesc);
+}
+
+static inline uint32_t gdma_dma_read(struct gdma_dma_dev *dma_dev,
+ unsigned int reg)
+{
+ return readl(dma_dev->base + reg);
+}
+
+static inline void gdma_dma_write(struct gdma_dma_dev *dma_dev,
+ unsigned reg, uint32_t val)
+{
+ writel(val, dma_dev->base + reg);
+}
+
+static struct gdma_dma_desc *gdma_dma_alloc_desc(unsigned int num_sgs)
+{
+ return kzalloc(sizeof(struct gdma_dma_desc) +
+ sizeof(struct gdma_dma_sg) * num_sgs, GFP_ATOMIC);
+}
+
+static enum gdma_dma_transfer_size gdma_dma_maxburst(u32 maxburst)
+{
+ if (maxburst < 2)
+ return GDMA_TRANSFER_SIZE_4BYTE;
+ else if (maxburst < 4)
+ return GDMA_TRANSFER_SIZE_8BYTE;
+ else if (maxburst < 8)
+ return GDMA_TRANSFER_SIZE_16BYTE;
+ else if (maxburst < 16)
+ return GDMA_TRANSFER_SIZE_32BYTE;
+ else
+ return GDMA_TRANSFER_SIZE_64BYTE;
+}
+
+static int gdma_dma_config(struct dma_chan *c,
+ struct dma_slave_config *config)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
+
+ if (config->device_fc) {
+ dev_err(dma_dev->ddev.dev, "not support flow controller\n");
+ return -EINVAL;
+ }
+
+ switch (config->direction) {
+ case DMA_MEM_TO_DEV:
+ if (config->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) {
+ dev_err(dma_dev->ddev.dev, "only support 4 byte buswidth\n");
+ return -EINVAL;
+ }
+ chan->slave_id = config->slave_id;
+ chan->fifo_addr = config->dst_addr;
+ chan->burst_size = gdma_dma_maxburst(config->dst_maxburst);
+ break;
+ case DMA_DEV_TO_MEM:
+ if (config->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) {
+ dev_err(dma_dev->ddev.dev, "only support 4 byte buswidth\n");
+ return -EINVAL;
+ }
+ chan->slave_id = config->slave_id;
+ chan->fifo_addr = config->src_addr;
+ chan->burst_size = gdma_dma_maxburst(config->src_maxburst);
+ break;
+ default:
+ dev_err(dma_dev->ddev.dev, "direction type %d error\n",
+ config->direction);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int gdma_dma_terminate_all(struct dma_chan *c)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
+ unsigned long flags, timeout;
+ LIST_HEAD(head);
+ int i = 0;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ chan->desc = NULL;
+ clear_bit(chan->id, &dma_dev->chan_issued);
+ vchan_get_all_descriptors(&chan->vchan, &head);
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+ vchan_dma_desc_free_list(&chan->vchan, &head);
+
+ /* wait dma transfer complete */
+ timeout = jiffies + msecs_to_jiffies(5000);
+ while (gdma_dma_read(dma_dev, GDMA_REG_CTRL0(chan->id)) &
+ GDMA_REG_CTRL0_ENABLE) {
+ if (time_after_eq(jiffies, timeout)) {
+ dev_err(dma_dev->ddev.dev, "chan %d wait timeout\n",
+ chan->id);
+ /* restore to init value */
+ gdma_dma_write(dma_dev, GDMA_REG_CTRL0(chan->id), 0);
+ break;
+ }
+ cpu_relax();
+ i++;
+ }
+
+ if (i)
+ dev_dbg(dma_dev->ddev.dev, "terminate chan %d loops %d\n",
+ chan->id, i);
+
+ return 0;
+}
+
+static void rt305x_dump_reg(struct gdma_dma_dev *dma_dev, int id)
+{
+ dev_dbg(dma_dev->ddev.dev, "chan %d, src %08x, dst %08x, ctr0 %08x, " \
+ "ctr1 %08x, intr %08x, signal %08x\n", id,
+ gdma_dma_read(dma_dev, GDMA_REG_SRC_ADDR(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_DST_ADDR(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_CTRL0(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_CTRL1(id)),
+ gdma_dma_read(dma_dev, GDMA_RT305X_STATUS_INT),
+ gdma_dma_read(dma_dev, GDMA_RT305X_STATUS_SIGNAL));
+}
+
+static int rt305x_gdma_start_transfer(struct gdma_dmaengine_chan *chan)
+{
+ struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
+ dma_addr_t src_addr, dst_addr;
+ struct gdma_dma_sg *sg;
+ uint32_t ctrl0, ctrl1;
+
+ /* verify chan is already stopped */
+ ctrl0 = gdma_dma_read(dma_dev, GDMA_REG_CTRL0(chan->id));
+ if (unlikely(ctrl0 & GDMA_REG_CTRL0_ENABLE)) {
+ dev_err(dma_dev->ddev.dev, "chan %d is start(%08x).\n",
+ chan->id, ctrl0);
+ rt305x_dump_reg(dma_dev, chan->id);
+ return -EINVAL;
+ }
+
+ sg = &chan->desc->sg[chan->next_sg];
+ if (chan->desc->direction == DMA_MEM_TO_DEV) {
+ src_addr = sg->src_addr;
+ dst_addr = chan->fifo_addr;
+ ctrl0 = GDMA_REG_CTRL0_DST_ADDR_FIXED | \
+ (8 << GDMA_RT305X_CTRL0_SRC_REQ_SHIFT) | \
+ (chan->slave_id << GDMA_RT305X_CTRL0_DST_REQ_SHIFT);
+ } else if (chan->desc->direction == DMA_DEV_TO_MEM) {
+ src_addr = chan->fifo_addr;
+ dst_addr = sg->dst_addr;
+ ctrl0 = GDMA_REG_CTRL0_SRC_ADDR_FIXED | \
+ (chan->slave_id << GDMA_RT305X_CTRL0_SRC_REQ_SHIFT) | \
+ (8 << GDMA_RT305X_CTRL0_DST_REQ_SHIFT);
+ } else if (chan->desc->direction == DMA_MEM_TO_MEM) {
+ /*
+ * TODO: memcpy function have bugs. sometime it will copy
+ * more 8 bytes data when using dmatest verify.
+ */
+ src_addr = sg->src_addr;
+ dst_addr = sg->dst_addr;
+ ctrl0 = GDMA_REG_CTRL0_SW_MODE | \
+ (8 << GDMA_REG_CTRL1_SRC_REQ_SHIFT) | \
+ (8 << GDMA_REG_CTRL1_DST_REQ_SHIFT);
+ } else {
+ dev_err(dma_dev->ddev.dev, "direction type %d error\n",
+ chan->desc->direction);
+ return -EINVAL;
+ }
+
+ ctrl0 |= (sg->len << GDMA_REG_CTRL0_TX_SHIFT) | \
+ (chan->burst_size << GDMA_REG_CTRL0_BURST_SHIFT) | \
+ GDMA_REG_CTRL0_DONE_INT | GDMA_REG_CTRL0_ENABLE;
+ ctrl1 = chan->id << GDMA_REG_CTRL1_NEXT_SHIFT;
+
+ chan->next_sg++;
+ gdma_dma_write(dma_dev, GDMA_REG_SRC_ADDR(chan->id), src_addr);
+ gdma_dma_write(dma_dev, GDMA_REG_DST_ADDR(chan->id), dst_addr);
+ gdma_dma_write(dma_dev, GDMA_REG_CTRL1(chan->id), ctrl1);
+
+ /* make sure next_sg is update */
+ wmb();
+ gdma_dma_write(dma_dev, GDMA_REG_CTRL0(chan->id), ctrl0);
+
+ return 0;
+}
+
+static void rt3883_dump_reg(struct gdma_dma_dev *dma_dev, int id)
+{
+ dev_dbg(dma_dev->ddev.dev, "chan %d, src %08x, dst %08x, ctr0 %08x, " \
+ "ctr1 %08x, unmask %08x, done %08x, " \
+ "req %08x, ack %08x, fin %08x\n", id,
+ gdma_dma_read(dma_dev, GDMA_REG_SRC_ADDR(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_DST_ADDR(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_CTRL0(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_CTRL1(id)),
+ gdma_dma_read(dma_dev, GDMA_REG_UNMASK_INT),
+ gdma_dma_read(dma_dev, GDMA_REG_DONE_INT),
+ gdma_dma_read(dma_dev, GDMA_REG_REQSTS),
+ gdma_dma_read(dma_dev, GDMA_REG_ACKSTS),
+ gdma_dma_read(dma_dev, GDMA_REG_FINSTS));
+}
+
+static int rt3883_gdma_start_transfer(struct gdma_dmaengine_chan *chan)
+{
+ struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
+ dma_addr_t src_addr, dst_addr;
+ struct gdma_dma_sg *sg;
+ uint32_t ctrl0, ctrl1;
+
+ /* verify chan is already stopped */
+ ctrl0 = gdma_dma_read(dma_dev, GDMA_REG_CTRL0(chan->id));
+ if (unlikely(ctrl0 & GDMA_REG_CTRL0_ENABLE)) {
+ dev_err(dma_dev->ddev.dev, "chan %d is start(%08x).\n",
+ chan->id, ctrl0);
+ rt3883_dump_reg(dma_dev, chan->id);
+ return -EINVAL;
+ }
+
+ sg = &chan->desc->sg[chan->next_sg];
+ if (chan->desc->direction == DMA_MEM_TO_DEV) {
+ src_addr = sg->src_addr;
+ dst_addr = chan->fifo_addr;
+ ctrl0 = GDMA_REG_CTRL0_DST_ADDR_FIXED;
+ ctrl1 = (32 << GDMA_REG_CTRL1_SRC_REQ_SHIFT) | \
+ (chan->slave_id << GDMA_REG_CTRL1_DST_REQ_SHIFT);
+ } else if (chan->desc->direction == DMA_DEV_TO_MEM) {
+ src_addr = chan->fifo_addr;
+ dst_addr = sg->dst_addr;
+ ctrl0 = GDMA_REG_CTRL0_SRC_ADDR_FIXED;
+ ctrl1 = (chan->slave_id << GDMA_REG_CTRL1_SRC_REQ_SHIFT) | \
+ (32 << GDMA_REG_CTRL1_DST_REQ_SHIFT) | \
+ GDMA_REG_CTRL1_COHERENT;
+ } else if (chan->desc->direction == DMA_MEM_TO_MEM) {
+ src_addr = sg->src_addr;
+ dst_addr = sg->dst_addr;
+ ctrl0 = GDMA_REG_CTRL0_SW_MODE;
+ ctrl1 = (32 << GDMA_REG_CTRL1_SRC_REQ_SHIFT) | \
+ (32 << GDMA_REG_CTRL1_DST_REQ_SHIFT) | \
+ GDMA_REG_CTRL1_COHERENT;
+ } else {
+ dev_err(dma_dev->ddev.dev, "direction type %d error\n",
+ chan->desc->direction);
+ return -EINVAL;
+ }
+
+ ctrl0 |= (sg->len << GDMA_REG_CTRL0_TX_SHIFT) | \
+ (chan->burst_size << GDMA_REG_CTRL0_BURST_SHIFT) | \
+ GDMA_REG_CTRL0_DONE_INT | GDMA_REG_CTRL0_ENABLE;
+ ctrl1 |= chan->id << GDMA_REG_CTRL1_NEXT_SHIFT;
+
+ chan->next_sg++;
+ gdma_dma_write(dma_dev, GDMA_REG_SRC_ADDR(chan->id), src_addr);
+ gdma_dma_write(dma_dev, GDMA_REG_DST_ADDR(chan->id), dst_addr);
+ gdma_dma_write(dma_dev, GDMA_REG_CTRL1(chan->id), ctrl1);
+
+ /* make sure next_sg is update */
+ wmb();
+ gdma_dma_write(dma_dev, GDMA_REG_CTRL0(chan->id), ctrl0);
+
+ return 0;
+}
+
+static inline int gdma_start_transfer(struct gdma_dma_dev *dma_dev,
+ struct gdma_dmaengine_chan *chan)
+{
+ return dma_dev->data->start_transfer(chan);
+}
+
+static int gdma_next_desc(struct gdma_dmaengine_chan *chan)
+{
+ struct virt_dma_desc *vdesc;
+
+ vdesc = vchan_next_desc(&chan->vchan);
+ if (!vdesc) {
+ chan->desc = NULL;
+ return 0;
+ }
+ chan->desc = to_gdma_dma_desc(vdesc);
+ chan->next_sg = 0;
+
+ return 1;
+}
+
+static void gdma_dma_chan_irq(struct gdma_dma_dev *dma_dev,
+ struct gdma_dmaengine_chan *chan)
+{
+ struct gdma_dma_desc *desc;
+ unsigned long flags;
+ int chan_issued;
+
+ chan_issued = 0;
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ desc = chan->desc;
+ if (desc) {
+ if (desc->cyclic) {
+ vchan_cyclic_callback(&desc->vdesc);
+ if (chan->next_sg == desc->num_sgs)
+ chan->next_sg = 0;
+ chan_issued = 1;
+ } else {
+ desc->residue -= desc->sg[chan->next_sg - 1].len;
+ if (chan->next_sg == desc->num_sgs) {
+ list_del(&desc->vdesc.node);
+ vchan_cookie_complete(&desc->vdesc);
+ chan_issued = gdma_next_desc(chan);
+ } else
+ chan_issued = 1;
+ }
+ } else
+ dev_dbg(dma_dev->ddev.dev, "chan %d no desc to complete\n",
+ chan->id);
+ if (chan_issued)
+ set_bit(chan->id, &dma_dev->chan_issued);
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static irqreturn_t gdma_dma_irq(int irq, void *devid)
+{
+ struct gdma_dma_dev *dma_dev = devid;
+ u32 done, done_reg;
+ unsigned int i;
+
+ done_reg = dma_dev->data->done_int_reg;
+ done = gdma_dma_read(dma_dev, done_reg);
+ if (unlikely(!done))
+ return IRQ_NONE;
+
+ /* clean done bits */
+ gdma_dma_write(dma_dev, done_reg, done);
+
+ i = 0;
+ while (done) {
+ if (done & 0x1) {
+ gdma_dma_chan_irq(dma_dev, &dma_dev->chan[i]);
+ atomic_dec(&dma_dev->cnt);
+ }
+ done >>= 1;
+ i++;
+ }
+
+ /* start only have work to do */
+ if (dma_dev->chan_issued)
+ tasklet_schedule(&dma_dev->task);
+
+ return IRQ_HANDLED;
+}
+
+static void gdma_dma_issue_pending(struct dma_chan *c)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_dev *dma_dev = gdma_dma_chan_get_dev(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
+ if (gdma_next_desc(chan)) {
+ set_bit(chan->id, &dma_dev->chan_issued);
+ tasklet_schedule(&dma_dev->task);
+ } else
+ dev_dbg(dma_dev->ddev.dev, "chan %d no desc to issue\n",
+ chan->id);
+ }
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static struct dma_async_tx_descriptor *gdma_dma_prep_slave_sg(
+ struct dma_chan *c, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_desc *desc;
+ struct scatterlist *sg;
+ unsigned int i;
+
+ desc = gdma_dma_alloc_desc(sg_len);
+ if (!desc) {
+ dev_err(c->device->dev, "alloc sg decs error\n");
+ return NULL;
+ }
+ desc->residue = 0;
+
+ for_each_sg(sgl, sg, sg_len, i) {
+ if (direction == DMA_MEM_TO_DEV)
+ desc->sg[i].src_addr = sg_dma_address(sg);
+ else if (direction == DMA_DEV_TO_MEM)
+ desc->sg[i].dst_addr = sg_dma_address(sg);
+ else {
+ dev_err(c->device->dev, "direction type %d error\n",
+ direction);
+ goto free_desc;
+ }
+
+ if (unlikely(sg_dma_len(sg) > GDMA_REG_CTRL0_TX_MASK)) {
+ dev_err(c->device->dev, "sg len too large %d\n",
+ sg_dma_len(sg));
+ goto free_desc;
+ }
+ desc->sg[i].len = sg_dma_len(sg);
+ desc->residue += sg_dma_len(sg);
+ }
+
+ desc->num_sgs = sg_len;
+ desc->direction = direction;
+ desc->cyclic = false;
+
+ return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+
+free_desc:
+ kfree(desc);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor * gdma_dma_prep_dma_memcpy(
+ struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
+ size_t len, unsigned long flags)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_desc *desc;
+ unsigned int num_periods, i;
+ size_t xfer_count;
+
+ if (len <= 0)
+ return NULL;
+
+ chan->burst_size = gdma_dma_maxburst(len >> 2);
+
+ xfer_count = GDMA_REG_CTRL0_TX_MASK;
+ num_periods = DIV_ROUND_UP(len, xfer_count);
+
+ desc = gdma_dma_alloc_desc(num_periods);
+ if (!desc) {
+ dev_err(c->device->dev, "alloc memcpy decs error\n");
+ return NULL;
+ }
+ desc->residue = len;
+
+ for (i = 0; i < num_periods; i++) {
+ desc->sg[i].src_addr = src;
+ desc->sg[i].dst_addr = dest;
+ if (len > xfer_count) {
+ desc->sg[i].len = xfer_count;
+ } else {
+ desc->sg[i].len = len;
+ }
+ src += desc->sg[i].len;
+ dest += desc->sg[i].len;
+ len -= desc->sg[i].len;
+ }
+
+ desc->num_sgs = num_periods;
+ desc->direction = DMA_MEM_TO_MEM;
+ desc->cyclic = false;
+
+ return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *gdma_dma_prep_dma_cyclic(
+ struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct gdma_dma_desc *desc;
+ unsigned int num_periods, i;
+
+ if (buf_len % period_len)
+ return NULL;
+
+ if (period_len > GDMA_REG_CTRL0_TX_MASK) {
+ dev_err(c->device->dev, "cyclic len too large %d\n",
+ period_len);
+ return NULL;
+ }
+
+ num_periods = buf_len / period_len;
+ desc = gdma_dma_alloc_desc(num_periods);
+ if (!desc) {
+ dev_err(c->device->dev, "alloc cyclic decs error\n");
+ return NULL;
+ }
+ desc->residue = buf_len;
+
+ for (i = 0; i < num_periods; i++) {
+ if (direction == DMA_MEM_TO_DEV)
+ desc->sg[i].src_addr = buf_addr;
+ else if (direction == DMA_DEV_TO_MEM)
+ desc->sg[i].dst_addr = buf_addr;
+ else {
+ dev_err(c->device->dev, "direction type %d error\n",
+ direction);
+ goto free_desc;
+ }
+ desc->sg[i].len = period_len;
+ buf_addr += period_len;
+ }
+
+ desc->num_sgs = num_periods;
+ desc->direction = direction;
+ desc->cyclic = true;
+
+ return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+
+free_desc:
+ kfree(desc);
+ return NULL;
+}
+
+static enum dma_status gdma_dma_tx_status(struct dma_chan *c,
+ dma_cookie_t cookie, struct dma_tx_state *state)
+{
+ struct gdma_dmaengine_chan *chan = to_gdma_dma_chan(c);
+ struct virt_dma_desc *vdesc;
+ enum dma_status status;
+ unsigned long flags;
+ struct gdma_dma_desc *desc;
+
+ status = dma_cookie_status(c, cookie, state);
+ if (status == DMA_COMPLETE || !state)
+ return status;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ desc = chan->desc;
+ if (desc && (cookie == desc->vdesc.tx.cookie)) {
+ /*
+ * We never update edesc->residue in the cyclic case, so we
+ * can tell the remaining room to the end of the circular
+ * buffer.
+ */
+ if (desc->cyclic)
+ state->residue = desc->residue -
+ ((chan->next_sg - 1) * desc->sg[0].len);
+ else
+ state->residue = desc->residue;
+ } else if ((vdesc = vchan_find_desc(&chan->vchan, cookie)))
+ state->residue = to_gdma_dma_desc(vdesc)->residue;
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+ dev_dbg(c->device->dev, "tx residue %d bytes\n", state->residue);
+
+ return status;
+}
+
+static void gdma_dma_free_chan_resources(struct dma_chan *c)
+{
+ vchan_free_chan_resources(to_virt_chan(c));
+}
+
+static void gdma_dma_desc_free(struct virt_dma_desc *vdesc)
+{
+ kfree(container_of(vdesc, struct gdma_dma_desc, vdesc));
+}
+
+static void gdma_dma_tasklet(unsigned long arg)
+{
+ struct gdma_dma_dev *dma_dev = (struct gdma_dma_dev *)arg;
+ struct gdma_dmaengine_chan *chan;
+ static unsigned int last_chan;
+ unsigned int i, chan_mask;
+
+ /* record last chan to round robin all chans */
+ i = last_chan;
+ chan_mask = dma_dev->data->chancnt - 1;
+ do {
+ /*
+ * on mt7621. when verify with dmatest with all
+ * channel is enable. we need to limit only two
+ * channel is working at the same time. otherwise the
+ * data will have problem.
+ */
+ if (atomic_read(&dma_dev->cnt) >= 2) {
+ last_chan = i;
+ break;
+ }
+
+ if (test_and_clear_bit(i, &dma_dev->chan_issued)) {
+ chan = &dma_dev->chan[i];
+ if (chan->desc) {
+ atomic_inc(&dma_dev->cnt);
+ gdma_start_transfer(dma_dev, chan);
+ } else
+ dev_dbg(dma_dev->ddev.dev, "chan %d no desc to issue\n", chan->id);
+
+ if (!dma_dev->chan_issued)
+ break;
+ }
+
+ i = (i + 1) & chan_mask;
+ } while (i != last_chan);
+}
+
+static void rt305x_gdma_init(struct gdma_dma_dev *dma_dev)
+{
+ uint32_t gct;
+
+ /* all chans round robin */
+ gdma_dma_write(dma_dev, GDMA_RT305X_GCT, GDMA_REG_GCT_ARBIT_RR);
+
+ gct = gdma_dma_read(dma_dev, GDMA_RT305X_GCT);
+ dev_info(dma_dev->ddev.dev, "revision: %d, channels: %d\n",
+ (gct >> GDMA_REG_GCT_VER_SHIFT) & GDMA_REG_GCT_VER_MASK,
+ 8 << ((gct >> GDMA_REG_GCT_CHAN_SHIFT) &
+ GDMA_REG_GCT_CHAN_MASK));
+}
+
+static void rt3883_gdma_init(struct gdma_dma_dev *dma_dev)
+{
+ uint32_t gct;
+
+ /* all chans round robin */
+ gdma_dma_write(dma_dev, GDMA_REG_GCT, GDMA_REG_GCT_ARBIT_RR);
+
+ gct = gdma_dma_read(dma_dev, GDMA_REG_GCT);
+ dev_info(dma_dev->ddev.dev, "revision: %d, channels: %d\n",
+ (gct >> GDMA_REG_GCT_VER_SHIFT) & GDMA_REG_GCT_VER_MASK,
+ 8 << ((gct >> GDMA_REG_GCT_CHAN_SHIFT) &
+ GDMA_REG_GCT_CHAN_MASK));
+}
+
+static struct gdma_data rt305x_gdma_data = {
+ .chancnt = 8,
+ .done_int_reg = GDMA_RT305X_STATUS_INT,
+ .init = rt305x_gdma_init,
+ .start_transfer = rt305x_gdma_start_transfer,
+};
+
+static struct gdma_data rt3883_gdma_data = {
+ .chancnt = 16,
+ .done_int_reg = GDMA_REG_DONE_INT,
+ .init = rt3883_gdma_init,
+ .start_transfer = rt3883_gdma_start_transfer,
+};
+
+static const struct of_device_id gdma_of_match_table[] = {
+ { .compatible = "ralink,rt305x-gdma", .data = &rt305x_gdma_data },
+ { .compatible = "ralink,rt3883-gdma", .data = &rt3883_gdma_data },
+ { },
+};
+
+static int gdma_dma_probe(struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+ struct gdma_dmaengine_chan *chan;
+ struct gdma_dma_dev *dma_dev;
+ struct dma_device *dd;
+ unsigned int i;
+ struct resource *res;
+ int ret;
+ int irq;
+ void __iomem *base;
+ struct gdma_data *data;
+
+ ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+
+ match = of_match_device(gdma_of_match_table, &pdev->dev);
+ if (!match)
+ return -EINVAL;
+ data = (struct gdma_data *) match->data;
+
+ dma_dev = devm_kzalloc(&pdev->dev, sizeof(*dma_dev) +
+ (sizeof(struct gdma_dmaengine_chan) * data->chancnt),
+ GFP_KERNEL);
+ if (!dma_dev) {
+ dev_err(&pdev->dev, "alloc dma device failed\n");
+ return -EINVAL;
+ }
+ dma_dev->data = data;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+ dma_dev->base = base;
+ tasklet_init(&dma_dev->task, gdma_dma_tasklet, (unsigned long)dma_dev);
+
+ 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, gdma_dma_irq,
+ 0, dev_name(&pdev->dev), dma_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq\n");
+ return ret;
+ }
+
+ device_reset(&pdev->dev);
+
+ dd = &dma_dev->ddev;
+ dma_cap_set(DMA_MEMCPY, dd->cap_mask);
+ dma_cap_set(DMA_SLAVE, dd->cap_mask);
+ dma_cap_set(DMA_CYCLIC, dd->cap_mask);
+ dd->device_free_chan_resources = gdma_dma_free_chan_resources;
+ dd->device_prep_dma_memcpy = gdma_dma_prep_dma_memcpy;
+ dd->device_prep_slave_sg = gdma_dma_prep_slave_sg;
+ dd->device_prep_dma_cyclic = gdma_dma_prep_dma_cyclic;
+ dd->device_config = gdma_dma_config;
+ dd->device_terminate_all = gdma_dma_terminate_all;
+ dd->device_tx_status = gdma_dma_tx_status;
+ dd->device_issue_pending = gdma_dma_issue_pending;
+
+ dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+ dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+ dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ dd->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+
+ dd->dev = &pdev->dev;
+ dd->dev->dma_parms = &dma_dev->dma_parms;
+ dma_set_max_seg_size(dd->dev, GDMA_REG_CTRL0_TX_MASK);
+ INIT_LIST_HEAD(&dd->channels);
+
+ for (i = 0; i < data->chancnt; i++) {
+ chan = &dma_dev->chan[i];
+ chan->id = i;
+ chan->vchan.desc_free = gdma_dma_desc_free;
+ vchan_init(&chan->vchan, dd);
+ }
+
+ /* init hardware */
+ data->init(dma_dev);
+
+ ret = dma_async_device_register(dd);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register dma device\n");
+ return ret;
+ }
+
+ ret = of_dma_controller_register(pdev->dev.of_node,
+ of_dma_xlate_by_chan_id, dma_dev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register of dma controller\n");
+ goto err_unregister;
+ }
+
+ platform_set_drvdata(pdev, dma_dev);
+
+ return 0;
+
+err_unregister:
+ dma_async_device_unregister(dd);
+ return ret;
+}
+
+static int gdma_dma_remove(struct platform_device *pdev)
+{
+ struct gdma_dma_dev *dma_dev = platform_get_drvdata(pdev);
+
+ tasklet_kill(&dma_dev->task);
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&dma_dev->ddev);
+
+ return 0;
+}
+
+static struct platform_driver gdma_dma_driver = {
+ .probe = gdma_dma_probe,
+ .remove = gdma_dma_remove,
+ .driver = {
+ .name = "gdma-rt2880",
+ .of_match_table = gdma_of_match_table,
+ },
+};
+module_platform_driver(gdma_dma_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Ralink/MTK DMA driver");
+MODULE_LICENSE("GPL v2");