staging: ralink-gdma: remove driver from tree
[linux-2.6-microblaze.git] / drivers / staging / ralink-gdma / ralink-gdma.c
diff --git a/drivers/staging/ralink-gdma/ralink-gdma.c b/drivers/staging/ralink-gdma/ralink-gdma.c
deleted file mode 100644 (file)
index b5229bc..0000000
+++ /dev/null
@@ -1,917 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- *  GDMA4740 DMAC support
- */
-
-#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_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 int reg, uint32_t val)
-{
-       writel(val, dma_dev->base + reg);
-}
-
-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;
-       u32 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;
-       u32 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 = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC);
-       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 = kzalloc(struct_size(desc, sg, num_periods), GFP_ATOMIC);
-       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 = kzalloc(struct_size(desc, sg, num_periods), GFP_ATOMIC);
-       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 {
-               vdesc = vchan_find_desc(&chan->vchan, cookie);
-               if (vdesc)
-                       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(struct tasklet_struct *t)
-{
-       struct gdma_dma_dev *dma_dev = from_tasklet(dma_dev, t, task);
-       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)
-{
-       u32 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)
-{
-       u32 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 },
-       { },
-};
-MODULE_DEVICE_TABLE(of, gdma_of_match_table);
-
-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;
-       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,
-                              struct_size(dma_dev, chan, data->chancnt),
-                              GFP_KERNEL);
-       if (!dma_dev)
-               return -EINVAL;
-       dma_dev->data = data;
-
-       base = devm_platform_ioremap_resource(pdev, 0);
-       if (IS_ERR(base))
-               return PTR_ERR(base);
-       dma_dev->base = base;
-       tasklet_setup(&dma_dev->task, gdma_dma_tasklet);
-
-       irq = platform_get_irq(pdev, 0);
-       if (irq < 0)
-               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;
-       }
-
-       ret = device_reset(&pdev->dev);
-       if (ret)
-               dev_err(&pdev->dev, "failed to reset: %d\n", ret);
-
-       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_DESCRIPTION("Ralink/MTK DMA driver");
-MODULE_LICENSE("GPL v2");