]> git.kernelconcepts.de Git - karo-tx-linux.git/commitdiff
sata_dwc_460ex: move to generic DMA driver
authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tue, 3 Mar 2015 20:41:21 +0000 (22:41 +0200)
committerTejun Heo <tj@kernel.org>
Tue, 24 Mar 2015 17:50:35 +0000 (13:50 -0400)
The SATA implementation based on two actually different devices, i.e. SATA and
DMA controllers.

For Synopsys DesignWare DMA we have already a generic implementation of the
driver. Thus, the patch converts the code to use DMAEngine framework and
dw_dmac driver.

In future it will be better to split the devices inside DTS as well like it's
done on other platforms.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
drivers/ata/sata_dwc_460ex.c

index 7bc0c12882b9c133983e041f5b258cfc428a2f99..08cd63fae7ef1c2430df0ec27ea529edfc2460c5 100644 (file)
 #include <linux/platform_device.h>
 #include <linux/libata.h>
 #include <linux/slab.h>
+
 #include "libata.h"
 
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_cmnd.h>
 
+/* Supported DMA engine drivers */
+#include <linux/platform_data/dma-dw.h>
+#include <linux/dma/dw.h>
+
 /* These two are defined in "libata.h" */
 #undef DRV_NAME
 #undef DRV_VERSION
 #define NO_IRQ         0
 #endif
 
-/* SATA DMA driver Globals */
-#define DMA_NUM_CHANS          1
-#define DMA_NUM_CHAN_REGS      8
-
-/* SATA DMA Register definitions */
 #define AHB_DMA_BRST_DFLT      64      /* 16 data items burst length*/
 
-struct dmareg {
-       u32 low;                /* Low bits 0-31 */
-       u32 high;               /* High bits 32-63 */
-};
-
-/* DMA Per Channel registers */
-struct dma_chan_regs {
-       struct dmareg sar;      /* Source Address */
-       struct dmareg dar;      /* Destination address */
-       struct dmareg llp;      /* Linked List Pointer */
-       struct dmareg ctl;      /* Control */
-       struct dmareg sstat;    /* Source Status not implemented in core */
-       struct dmareg dstat;    /* Destination Status not implemented in core*/
-       struct dmareg sstatar;  /* Source Status Address not impl in core */
-       struct dmareg dstatar;  /* Destination Status Address not implemente */
-       struct dmareg cfg;      /* Config */
-       struct dmareg sgr;      /* Source Gather */
-       struct dmareg dsr;      /* Destination Scatter */
-};
-
-/* Generic Interrupt Registers */
-struct dma_interrupt_regs {
-       struct dmareg tfr;      /* Transfer Interrupt */
-       struct dmareg block;    /* Block Interrupt */
-       struct dmareg srctran;  /* Source Transfer Interrupt */
-       struct dmareg dsttran;  /* Dest Transfer Interrupt */
-       struct dmareg error;    /* Error */
-};
-
-struct ahb_dma_regs {
-       struct dma_chan_regs    chan_regs[DMA_NUM_CHAN_REGS];
-       struct dma_interrupt_regs interrupt_raw;        /* Raw Interrupt */
-       struct dma_interrupt_regs interrupt_status;     /* Interrupt Status */
-       struct dma_interrupt_regs interrupt_mask;       /* Interrupt Mask */
-       struct dma_interrupt_regs interrupt_clear;      /* Interrupt Clear */
-       struct dmareg           statusInt;      /* Interrupt combined*/
-       struct dmareg           rq_srcreg;      /* Src Trans Req */
-       struct dmareg           rq_dstreg;      /* Dst Trans Req */
-       struct dmareg           rq_sgl_srcreg;  /* Sngl Src Trans Req*/
-       struct dmareg           rq_sgl_dstreg;  /* Sngl Dst Trans Req*/
-       struct dmareg           rq_lst_srcreg;  /* Last Src Trans Req*/
-       struct dmareg           rq_lst_dstreg;  /* Last Dst Trans Req*/
-       struct dmareg           dma_cfg;                /* DMA Config */
-       struct dmareg           dma_chan_en;            /* DMA Channel Enable*/
-       struct dmareg           dma_id;                 /* DMA ID */
-       struct dmareg           dma_test;               /* DMA Test */
-       struct dmareg           res1;                   /* reserved */
-       struct dmareg           res2;                   /* reserved */
-       /*
-        * DMA Comp Params
-        * Param 6 = dma_param[0], Param 5 = dma_param[1],
-        * Param 4 = dma_param[2] ...
-        */
-       struct dmareg           dma_params[6];
-};
-
-/* Data structure for linked list item */
-struct lli {
-       u32             sar;            /* Source Address */
-       u32             dar;            /* Destination address */
-       u32             llp;            /* Linked List Pointer */
-       struct dmareg   ctl;            /* Control */
-       struct dmareg   dstat;          /* Destination Status */
-};
-
-enum {
-       SATA_DWC_DMAC_LLI_SZ =  (sizeof(struct lli)),
-       SATA_DWC_DMAC_LLI_NUM = 256,
-       SATA_DWC_DMAC_LLI_TBL_SZ = (SATA_DWC_DMAC_LLI_SZ * \
-                                       SATA_DWC_DMAC_LLI_NUM),
-       SATA_DWC_DMAC_TWIDTH_BYTES = 4,
-       SATA_DWC_DMAC_CTRL_TSIZE_MAX = (0x00000800 * \
-                                               SATA_DWC_DMAC_TWIDTH_BYTES),
-};
-
-/* DMA Register Operation Bits */
 enum {
-       DMA_EN  =               0x00000001, /* Enable AHB DMA */
-       DMA_CTL_LLP_SRCEN =     0x10000000, /* Blk chain enable Src */
-       DMA_CTL_LLP_DSTEN =     0x08000000, /* Blk chain enable Dst */
-};
-
-#define        DMA_CTL_BLK_TS(size)    ((size) & 0x000000FFF)  /* Blk Transfer size */
-#define DMA_CHANNEL(ch)                (0x00000001 << (ch))    /* Select channel */
-       /* Enable channel */
-#define        DMA_ENABLE_CHAN(ch)     ((0x00000001 << (ch)) |                 \
-                                ((0x000000001 << (ch)) << 8))
-       /* Disable channel */
-#define        DMA_DISABLE_CHAN(ch)    (0x00000000 | ((0x000000001 << (ch)) << 8))
-       /* Transfer Type & Flow Controller */
-#define        DMA_CTL_TTFC(type)      (((type) & 0x7) << 20)
-#define        DMA_CTL_SMS(num)        (((num) & 0x3) << 25) /* Src Master Select */
-#define        DMA_CTL_DMS(num)        (((num) & 0x3) << 23)/* Dst Master Select */
-       /* Src Burst Transaction Length */
-#define DMA_CTL_SRC_MSIZE(size) (((size) & 0x7) << 14)
-       /* Dst Burst Transaction Length */
-#define        DMA_CTL_DST_MSIZE(size) (((size) & 0x7) << 11)
-       /* Source Transfer Width */
-#define        DMA_CTL_SRC_TRWID(size) (((size) & 0x7) << 4)
-       /* Destination Transfer Width */
-#define        DMA_CTL_DST_TRWID(size) (((size) & 0x7) << 1)
-
-/* Assign HW handshaking interface (x) to destination / source peripheral */
-#define        DMA_CFG_HW_HS_DEST(int_num) (((int_num) & 0xF) << 11)
-#define        DMA_CFG_HW_HS_SRC(int_num) (((int_num) & 0xF) << 7)
-#define        DMA_CFG_HW_CH_PRIOR(int_num) (((int_num) & 0xF) << 5)
-#define        DMA_LLP_LMS(addr, master) (((addr) & 0xfffffffc) | (master))
-
-/*
- * This define is used to set block chaining disabled in the control low
- * register.  It is already in little endian format so it can be &'d dirctly.
- * It is essentially: cpu_to_le32(~(DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN))
- */
-enum {
-       DMA_CTL_LLP_DISABLE_LE32 = 0xffffffe7,
-       DMA_CTL_TTFC_P2M_DMAC = 0x00000002, /* Per to mem, DMAC cntr */
-       DMA_CTL_TTFC_M2P_PER =  0x00000003, /* Mem to per, peripheral cntr */
-       DMA_CTL_SINC_INC =      0x00000000, /* Source Address Increment */
-       DMA_CTL_SINC_DEC =      0x00000200,
-       DMA_CTL_SINC_NOCHANGE = 0x00000400,
-       DMA_CTL_DINC_INC =      0x00000000, /* Destination Address Increment */
-       DMA_CTL_DINC_DEC =      0x00000080,
-       DMA_CTL_DINC_NOCHANGE = 0x00000100,
-       DMA_CTL_INT_EN =        0x00000001, /* Interrupt Enable */
-
-/* Channel Configuration Register high bits */
-       DMA_CFG_FCMOD_REQ =     0x00000001, /* Flow Control - request based */
-       DMA_CFG_PROTCTL =       (0x00000003 << 2),/* Protection Control */
-
-/* Channel Configuration Register low bits */
-       DMA_CFG_RELD_DST =      0x80000000, /* Reload Dest / Src Addr */
-       DMA_CFG_RELD_SRC =      0x40000000,
-       DMA_CFG_HS_SELSRC =     0x00000800, /* Software handshake Src/ Dest */
-       DMA_CFG_HS_SELDST =     0x00000400,
-       DMA_CFG_FIFOEMPTY =     (0x00000001 << 9), /* FIFO Empty bit */
-
-/* Channel Linked List Pointer Register */
-       DMA_LLP_AHBMASTER1 =    0,      /* List Master Select */
-       DMA_LLP_AHBMASTER2 =    1,
-
        SATA_DWC_MAX_PORTS = 1,
 
        SATA_DWC_SCR_OFFSET = 0x24,
@@ -287,7 +148,7 @@ struct sata_dwc_device {
        struct ata_host         *host;
        u8 __iomem              *reg_base;
        struct sata_dwc_regs    *sata_dwc_regs; /* DW Synopsys SATA specific */
-       int                     irq_dma;
+       struct dw_dma_chip      *dma;
 };
 
 #define SATA_DWC_QCMD_MAX      32
@@ -295,10 +156,13 @@ struct sata_dwc_device {
 struct sata_dwc_device_port {
        struct sata_dwc_device  *hsdev;
        int                     cmd_issued[SATA_DWC_QCMD_MAX];
-       struct lli              *llit[SATA_DWC_QCMD_MAX];  /* DMA LLI table */
-       dma_addr_t              llit_dma[SATA_DWC_QCMD_MAX];
-       u32                     dma_chan[SATA_DWC_QCMD_MAX];
        int                     dma_pending[SATA_DWC_QCMD_MAX];
+
+       /* DMA info */
+       struct dw_dma_slave             *dws;
+       struct dma_chan                 *chan;
+       struct dma_async_tx_descriptor  *desc[SATA_DWC_QCMD_MAX];
+       u32                             dma_interrupt_count;
 };
 
 /*
@@ -330,14 +194,18 @@ struct sata_dwc_host_priv {
        void    __iomem  *scr_addr_sstatus;
        u32     sata_dwc_sactive_issued ;
        u32     sata_dwc_sactive_queued ;
-       u32     dma_interrupt_count;
-       struct  ahb_dma_regs    *sata_dma_regs;
        struct  device  *dwc_dev;
-       int     dma_channel;
 };
 
 static struct sata_dwc_host_priv host_pvt;
 
+static struct dw_dma_slave sata_dwc_dma_dws = {
+       .src_id = 0,
+       .dst_id = 0,
+       .src_master = 0,
+       .dst_master = 1,
+};
+
 /*
  * Prototypes
  */
@@ -347,12 +215,6 @@ static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
 static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
 static void sata_dwc_port_stop(struct ata_port *ap);
 static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
-static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq);
-static void dma_dwc_exit(struct sata_dwc_device *hsdev);
-static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
-                             struct lli *lli, dma_addr_t dma_lli,
-                             void __iomem *addr, int dir);
-static void dma_dwc_xfer_start(int dma_ch);
 
 static const char *get_prot_descript(u8 protocol)
 {
@@ -405,76 +267,8 @@ static void sata_dwc_tf_dump(struct ata_taskfile *tf)
                tf->hob_lbah);
 }
 
-/*
- * Function: get_burst_length_encode
- * arguments: datalength: length in bytes of data
- * returns value to be programmed in register corresponding to data length
- * This value is effectively the log(base 2) of the length
- */
-static  int get_burst_length_encode(int datalength)
-{
-       int items = datalength >> 2;    /* div by 4 to get lword count */
-
-       if (items >= 64)
-               return 5;
-
-       if (items >= 32)
-               return 4;
-
-       if (items >= 16)
-               return 3;
-
-       if (items >= 8)
-               return 2;
-
-       if (items >= 4)
-               return 1;
-
-       return 0;
-}
-
-static  void clear_chan_interrupts(int c)
+static void dma_dwc_xfer_done(void *hsdev_instance)
 {
-       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.tfr.low),
-                DMA_CHANNEL(c));
-       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.block.low),
-                DMA_CHANNEL(c));
-       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.srctran.low),
-                DMA_CHANNEL(c));
-       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.dsttran.low),
-                DMA_CHANNEL(c));
-       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.error.low),
-                DMA_CHANNEL(c));
-}
-
-/*
- * Function: dma_request_channel
- * arguments: None
- * returns channel number if available else -1
- * This function assigns the next available DMA channel from the list to the
- * requester
- */
-static int dma_request_channel(void)
-{
-       /* Check if the channel is not currently in use */
-       if (!(in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) &
-               DMA_CHANNEL(host_pvt.dma_channel)))
-               return host_pvt.dma_channel;
-       dev_err(host_pvt.dwc_dev, "%s Channel %d is currently in use\n",
-               __func__, host_pvt.dma_channel);
-       return -1;
-}
-
-/*
- * Function: dma_dwc_interrupt
- * arguments: irq, dev_id, pt_regs
- * returns channel number if available else -1
- * Interrupt Handler for DW AHB SATA DMA
- */
-static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
-{
-       int chan;
-       u32 tfr_reg, err_reg;
        unsigned long flags;
        struct sata_dwc_device *hsdev = hsdev_instance;
        struct ata_host *host = (struct ata_host *)hsdev->host;
@@ -488,341 +282,65 @@ static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
        hsdevp = HSDEVP_FROM_AP(ap);
        tag = ap->link.active_tag;
 
-       tfr_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.tfr\
-                       .low));
-       err_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.error\
-                       .low));
-
-       dev_dbg(ap->dev, "eot=0x%08x err=0x%08x pending=%d active port=%d\n",
-               tfr_reg, err_reg, hsdevp->dma_pending[tag], port);
-
-       chan = host_pvt.dma_channel;
-       if (chan >= 0) {
-               /* Check for end-of-transfer interrupt. */
-               if (tfr_reg & DMA_CHANNEL(chan)) {
-                       /*
-                        * Each DMA command produces 2 interrupts.  Only
-                        * complete the command after both interrupts have been
-                        * seen. (See sata_dwc_isr())
-                        */
-                       host_pvt.dma_interrupt_count++;
-                       sata_dwc_clear_dmacr(hsdevp, tag);
-
-                       if (hsdevp->dma_pending[tag] ==
-                           SATA_DWC_DMA_PENDING_NONE) {
-                               dev_err(ap->dev, "DMA not pending eot=0x%08x "
-                                       "err=0x%08x tag=0x%02x pending=%d\n",
-                                       tfr_reg, err_reg, tag,
-                                       hsdevp->dma_pending[tag]);
-                       }
-
-                       if ((host_pvt.dma_interrupt_count % 2) == 0)
-                               sata_dwc_dma_xfer_complete(ap, 1);
-
-                       /* Clear the interrupt */
-                       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear\
-                               .tfr.low),
-                                DMA_CHANNEL(chan));
-               }
-
-               /* Check for error interrupt. */
-               if (err_reg & DMA_CHANNEL(chan)) {
-                       /* TODO Need error handler ! */
-                       dev_err(ap->dev, "error interrupt err_reg=0x%08x\n",
-                               err_reg);
-
-                       /* Clear the interrupt. */
-                       out_le32(&(host_pvt.sata_dma_regs->interrupt_clear\
-                               .error.low),
-                                DMA_CHANNEL(chan));
-               }
-       }
-       spin_unlock_irqrestore(&host->lock, flags);
-       return IRQ_HANDLED;
-}
-
-/*
- * Function: dma_request_interrupts
- * arguments: hsdev
- * returns status
- * This function registers ISR for a particular DMA channel interrupt
- */
-static int dma_request_interrupts(struct sata_dwc_device *hsdev, int irq)
-{
-       int retval = 0;
-       int chan = host_pvt.dma_channel;
-
-       if (chan >= 0) {
-               /* Unmask error interrupt */
-               out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.error.low,
-                        DMA_ENABLE_CHAN(chan));
-
-               /* Unmask end-of-transfer interrupt */
-               out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.tfr.low,
-                        DMA_ENABLE_CHAN(chan));
-       }
-
-       retval = request_irq(irq, dma_dwc_interrupt, 0, "SATA DMA", hsdev);
-       if (retval) {
-               dev_err(host_pvt.dwc_dev, "%s: could not get IRQ %d\n",
-               __func__, irq);
-               return -ENODEV;
-       }
-
-       /* Mark this interrupt as requested */
-       hsdev->irq_dma = irq;
-       return 0;
-}
-
-/*
- * Function: map_sg_to_lli
- * The Synopsis driver has a comment proposing that better performance
- * is possible by only enabling interrupts on the last item in the linked list.
- * However, it seems that could be a problem if an error happened on one of the
- * first items.  The transfer would halt, but no error interrupt would occur.
- * Currently this function sets interrupts enabled for each linked list item:
- * DMA_CTL_INT_EN.
- */
-static int map_sg_to_lli(struct scatterlist *sg, int num_elems,
-                       struct lli *lli, dma_addr_t dma_lli,
-                       void __iomem *dmadr_addr, int dir)
-{
-       int i, idx = 0;
-       int fis_len = 0;
-       dma_addr_t next_llp;
-       int bl;
-       int sms_val, dms_val;
-
-       sms_val = 0;
-       dms_val = 1 + host_pvt.dma_channel;
-       dev_dbg(host_pvt.dwc_dev,
-               "%s: sg=%p nelem=%d lli=%p dma_lli=0x%pad dmadr=0x%p\n",
-               __func__, sg, num_elems, lli, &dma_lli, dmadr_addr);
-
-       bl = get_burst_length_encode(AHB_DMA_BRST_DFLT);
-
-       for (i = 0; i < num_elems; i++, sg++) {
-               u32 addr, offset;
-               u32 sg_len, len;
-
-               addr = (u32) sg_dma_address(sg);
-               sg_len = sg_dma_len(sg);
-
-               dev_dbg(host_pvt.dwc_dev, "%s: elem=%d sg_addr=0x%x sg_len"
-                       "=%d\n", __func__, i, addr, sg_len);
-
-               while (sg_len) {
-                       if (idx >= SATA_DWC_DMAC_LLI_NUM) {
-                               /* The LLI table is not large enough. */
-                               dev_err(host_pvt.dwc_dev, "LLI table overrun "
-                               "(idx=%d)\n", idx);
-                               break;
-                       }
-                       len = (sg_len > SATA_DWC_DMAC_CTRL_TSIZE_MAX) ?
-                               SATA_DWC_DMAC_CTRL_TSIZE_MAX : sg_len;
-
-                       offset = addr & 0xffff;
-                       if ((offset + sg_len) > 0x10000)
-                               len = 0x10000 - offset;
-
-                       /*
-                        * Make sure a LLI block is not created that will span
-                        * 8K max FIS boundary.  If the block spans such a FIS
-                        * boundary, there is a chance that a DMA burst will
-                        * cross that boundary -- this results in an error in
-                        * the host controller.
-                        */
-                       if (fis_len + len > 8192) {
-                               dev_dbg(host_pvt.dwc_dev, "SPLITTING: fis_len="
-                                       "%d(0x%x) len=%d(0x%x)\n", fis_len,
-                                        fis_len, len, len);
-                               len = 8192 - fis_len;
-                               fis_len = 0;
-                       } else {
-                               fis_len += len;
-                       }
-                       if (fis_len == 8192)
-                               fis_len = 0;
-
-                       /*
-                        * Set DMA addresses and lower half of control register
-                        * based on direction.
-                        */
-                       if (dir == DMA_FROM_DEVICE) {
-                               lli[idx].dar = cpu_to_le32(addr);
-                               lli[idx].sar = cpu_to_le32((u32)dmadr_addr);
-
-                               lli[idx].ctl.low = cpu_to_le32(
-                                       DMA_CTL_TTFC(DMA_CTL_TTFC_P2M_DMAC) |
-                                       DMA_CTL_SMS(sms_val) |
-                                       DMA_CTL_DMS(dms_val) |
-                                       DMA_CTL_SRC_MSIZE(bl) |
-                                       DMA_CTL_DST_MSIZE(bl) |
-                                       DMA_CTL_SINC_NOCHANGE |
-                                       DMA_CTL_SRC_TRWID(2) |
-                                       DMA_CTL_DST_TRWID(2) |
-                                       DMA_CTL_INT_EN |
-                                       DMA_CTL_LLP_SRCEN |
-                                       DMA_CTL_LLP_DSTEN);
-                       } else {        /* DMA_TO_DEVICE */
-                               lli[idx].sar = cpu_to_le32(addr);
-                               lli[idx].dar = cpu_to_le32((u32)dmadr_addr);
-
-                               lli[idx].ctl.low = cpu_to_le32(
-                                       DMA_CTL_TTFC(DMA_CTL_TTFC_M2P_PER) |
-                                       DMA_CTL_SMS(dms_val) |
-                                       DMA_CTL_DMS(sms_val) |
-                                       DMA_CTL_SRC_MSIZE(bl) |
-                                       DMA_CTL_DST_MSIZE(bl) |
-                                       DMA_CTL_DINC_NOCHANGE |
-                                       DMA_CTL_SRC_TRWID(2) |
-                                       DMA_CTL_DST_TRWID(2) |
-                                       DMA_CTL_INT_EN |
-                                       DMA_CTL_LLP_SRCEN |
-                                       DMA_CTL_LLP_DSTEN);
-                       }
-
-                       dev_dbg(host_pvt.dwc_dev, "%s setting ctl.high len: "
-                               "0x%08x val: 0x%08x\n", __func__,
-                               len, DMA_CTL_BLK_TS(len / 4));
-
-                       /* Program the LLI CTL high register */
-                       lli[idx].ctl.high = cpu_to_le32(DMA_CTL_BLK_TS\
-                                               (len / 4));
-
-                       /* Program the next pointer.  The next pointer must be
-                        * the physical address, not the virtual address.
-                        */
-                       next_llp = (dma_lli + ((idx + 1) * sizeof(struct \
-                                                       lli)));
-
-                       /* The last 2 bits encode the list master select. */
-                       next_llp = DMA_LLP_LMS(next_llp, DMA_LLP_AHBMASTER2);
-
-                       lli[idx].llp = cpu_to_le32(next_llp);
-                       idx++;
-                       sg_len -= len;
-                       addr += len;
-               }
-       }
-
        /*
-        * The last next ptr has to be zero and the last control low register
-        * has to have LLP_SRC_EN and LLP_DST_EN (linked list pointer source
-        * and destination enable) set back to 0 (disabled.) This is what tells
-        * the core that this is the last item in the linked list.
+        * Each DMA command produces 2 interrupts.  Only
+        * complete the command after both interrupts have been
+        * seen. (See sata_dwc_isr())
         */
-       if (idx) {
-               lli[idx-1].llp = 0x00000000;
-               lli[idx-1].ctl.low &= DMA_CTL_LLP_DISABLE_LE32;
+       hsdevp->dma_interrupt_count++;
+       sata_dwc_clear_dmacr(hsdevp, tag);
 
-               /* Flush cache to memory */
-               dma_cache_sync(NULL, lli, (sizeof(struct lli) * idx),
-                              DMA_BIDIRECTIONAL);
+       if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
+               dev_err(ap->dev, "DMA not pending tag=0x%02x pending=%d\n",
+                       tag, hsdevp->dma_pending[tag]);
        }
 
-       return idx;
-}
+       if ((hsdevp->dma_interrupt_count % 2) == 0)
+       sata_dwc_dma_xfer_complete(ap, 1);
 
-/*
- * Function: dma_dwc_xfer_start
- * arguments: Channel number
- * Return : None
- * Enables the DMA channel
- */
-static void dma_dwc_xfer_start(int dma_ch)
-{
-       /* Enable the DMA channel */
-       out_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low),
-                in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) |
-                DMA_ENABLE_CHAN(dma_ch));
+       spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
-                             struct lli *lli, dma_addr_t dma_lli,
-                             void __iomem *addr, int dir)
+static struct dma_async_tx_descriptor *dma_dwc_xfer_setup(struct ata_queued_cmd *qc)
 {
-       int dma_ch;
-       int num_lli;
-       /* Acquire DMA channel */
-       dma_ch = dma_request_channel();
-       if (dma_ch == -1) {
-               dev_err(host_pvt.dwc_dev, "%s: dma channel unavailable\n",
-                        __func__);
-               return -EAGAIN;
+       struct ata_port *ap = qc->ap;
+       struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+       struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
+       dma_addr_t addr = (dma_addr_t)&hsdev->sata_dwc_regs->dmadr;
+       struct dma_slave_config sconf;
+       struct dma_async_tx_descriptor *desc;
+
+       if (qc->dma_dir == DMA_DEV_TO_MEM) {
+               sconf.src_addr = addr;
+               sconf.device_fc = true;
+       } else {        /* DMA_MEM_TO_DEV */
+               sconf.dst_addr = addr;
+               sconf.device_fc = false;
        }
 
-       /* Convert SG list to linked list of items (LLIs) for AHB DMA */
-       num_lli = map_sg_to_lli(sg, num_elems, lli, dma_lli, addr, dir);
-
-       dev_dbg(host_pvt.dwc_dev, "%s sg: 0x%p, count: %d lli: %p dma_lli:"
-               " 0x%0xlx addr: %p lli count: %d\n", __func__, sg, num_elems,
-                lli, (u32)dma_lli, addr, num_lli);
-
-       clear_chan_interrupts(dma_ch);
-
-       /* Program the CFG register. */
-       out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.high),
-                DMA_CFG_HW_HS_SRC(dma_ch) | DMA_CFG_HW_HS_DEST(dma_ch) |
-                DMA_CFG_PROTCTL | DMA_CFG_FCMOD_REQ);
-       out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.low),
-                DMA_CFG_HW_CH_PRIOR(dma_ch));
-
-       /* Program the address of the linked list */
-       out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].llp.low),
-                DMA_LLP_LMS(dma_lli, DMA_LLP_AHBMASTER2));
-
-       /* Program the CTL register with src enable / dst enable */
-       out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].ctl.low),
-                DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN);
-       return dma_ch;
-}
-
-/*
- * Function: dma_dwc_exit
- * arguments: None
- * returns status
- * This function exits the SATA DMA driver
- */
-static void dma_dwc_exit(struct sata_dwc_device *hsdev)
-{
-       dev_dbg(host_pvt.dwc_dev, "%s:\n", __func__);
-       if (host_pvt.sata_dma_regs) {
-               iounmap((void __iomem *)host_pvt.sata_dma_regs);
-               host_pvt.sata_dma_regs = NULL;
-       }
+       sconf.direction = qc->dma_dir;
+       sconf.src_maxburst = AHB_DMA_BRST_DFLT;
+       sconf.dst_maxburst = AHB_DMA_BRST_DFLT;
+       sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+       sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 
-       if (hsdev->irq_dma) {
-               free_irq(hsdev->irq_dma, hsdev);
-               hsdev->irq_dma = 0;
-       }
-}
+       dmaengine_slave_config(hsdevp->chan, &sconf);
 
-/*
- * Function: dma_dwc_init
- * arguments: hsdev
- * returns status
- * This function initializes the SATA DMA driver
- */
-static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq)
-{
-       int err;
+       /* Convert SG list to linked list of items (LLIs) for AHB DMA */
+       desc = dmaengine_prep_slave_sg(hsdevp->chan, qc->sg, qc->n_elem,
+                                      qc->dma_dir,
+                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 
-       err = dma_request_interrupts(hsdev, irq);
-       if (err) {
-               dev_err(host_pvt.dwc_dev, "%s: dma_request_interrupts returns"
-                       " %d\n", __func__, err);
-               return err;
-       }
+       if (!desc)
+               return NULL;
 
-       /* Enabe DMA */
-       out_le32(&(host_pvt.sata_dma_regs->dma_cfg.low), DMA_EN);
+       desc->callback = dma_dwc_xfer_done;
+       desc->callback_param = hsdev;
 
-       dev_notice(host_pvt.dwc_dev, "DMA initialized\n");
-       dev_dbg(host_pvt.dwc_dev, "SATA DMA registers=0x%p\n", host_pvt.\
-               sata_dma_regs);
+       dev_dbg(host_pvt.dwc_dev, "%s sg: 0x%p, count: %d addr: %pad\n",
+               __func__, qc->sg, qc->n_elem, &addr);
 
-       return 0;
+       return desc;
 }
 
 static int sata_dwc_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
@@ -892,21 +410,18 @@ static void sata_dwc_error_intr(struct ata_port *ap,
        struct ata_queued_cmd *qc;
        u32 serror;
        u8 status, tag;
-       u32 err_reg;
 
        ata_ehi_clear_desc(ehi);
 
        serror = core_scr_read(SCR_ERROR);
        status = ap->ops->sff_check_status(ap);
 
-       err_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.error.\
-                       low));
        tag = ap->link.active_tag;
 
-       dev_err(ap->dev, "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x "
-               "dma_intp=%d pending=%d issued=%d dma_err_status=0x%08x\n",
-               __func__, serror, intpr, status, host_pvt.dma_interrupt_count,
-               hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag], err_reg);
+       dev_err(ap->dev,
+               "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x dma_intp=%d pending=%d issued=%d",
+               __func__, serror, intpr, status, hsdevp->dma_interrupt_count,
+               hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag]);
 
        /* Clear error register and interrupt bit */
        clear_serror();
@@ -1033,7 +548,7 @@ DRVSTILLBUSY:
                         * operation done interrupt. The command should be
                         * completed only after both interrupts are seen.
                         */
-                       host_pvt.dma_interrupt_count++;
+                       hsdevp->dma_interrupt_count++;
                        if (hsdevp->dma_pending[tag] == \
                                        SATA_DWC_DMA_PENDING_NONE) {
                                dev_err(ap->dev,
@@ -1042,7 +557,7 @@ DRVSTILLBUSY:
                                        hsdevp->dma_pending[tag]);
                        }
 
-                       if ((host_pvt.dma_interrupt_count % 2) == 0)
+                       if ((hsdevp->dma_interrupt_count % 2) == 0)
                                sata_dwc_dma_xfer_complete(ap, 1);
                } else if (ata_is_pio(qc->tf.protocol)) {
                        ata_sff_hsm_move(ap, qc, status, 0);
@@ -1116,12 +631,12 @@ DRVSTILLBUSY:
                dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
                        get_prot_descript(qc->tf.protocol));
                if (ata_is_dma(qc->tf.protocol)) {
-                       host_pvt.dma_interrupt_count++;
+                       hsdevp->dma_interrupt_count++;
                        if (hsdevp->dma_pending[tag] == \
                                        SATA_DWC_DMA_PENDING_NONE)
                                dev_warn(ap->dev, "%s: DMA not pending?\n",
                                        __func__);
-                       if ((host_pvt.dma_interrupt_count % 2) == 0)
+                       if ((hsdevp->dma_interrupt_count % 2) == 0)
                                sata_dwc_dma_xfer_complete(ap, 1);
                } else {
                        if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
@@ -1269,6 +784,18 @@ static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
                in_le32(&hsdev->sata_dwc_regs->errmr));
 }
 
+static bool sata_dwc_dma_filter(struct dma_chan *chan, void *param)
+{
+       struct sata_dwc_device_port *hsdevp = param;
+       struct dw_dma_slave *dws = hsdevp->dws;
+
+       if (dws->dma_dev != chan->device->dev)
+               return false;
+
+       chan->private = dws;
+       return true;
+}
+
 static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
 {
        port->cmd_addr = (void __iomem *)base + 0x00;
@@ -1303,6 +830,7 @@ static int sata_dwc_port_start(struct ata_port *ap)
        struct sata_dwc_device *hsdev;
        struct sata_dwc_device_port *hsdevp = NULL;
        struct device *pdev;
+       dma_cap_mask_t mask;
        int i;
 
        hsdev = HSDEV_FROM_AP(ap);
@@ -1326,29 +854,27 @@ static int sata_dwc_port_start(struct ata_port *ap)
        }
        hsdevp->hsdev = hsdev;
 
+       hsdevp->dws = &sata_dwc_dma_dws;
+       hsdevp->dws->dma_dev = host_pvt.dwc_dev;
+
+       dma_cap_zero(mask);
+       dma_cap_set(DMA_SLAVE, mask);
+
+       /* Acquire DMA channel */
+       hsdevp->chan = dma_request_channel(mask, sata_dwc_dma_filter, hsdevp);
+       if (!hsdevp->chan) {
+               dev_err(host_pvt.dwc_dev, "%s: dma channel unavailable\n",
+                        __func__);
+               err = -EAGAIN;
+               goto CLEANUP_ALLOC;
+       }
+
        for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
                hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
 
        ap->bmdma_prd = NULL;   /* set these so libata doesn't use them */
        ap->bmdma_prd_dma = 0;
 
-       /*
-        * DMA - Assign scatter gather LLI table. We can't use the libata
-        * version since it's PRD is IDE PCI specific.
-        */
-       for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
-               hsdevp->llit[i] = dma_alloc_coherent(pdev,
-                                                    SATA_DWC_DMAC_LLI_TBL_SZ,
-                                                    &(hsdevp->llit_dma[i]),
-                                                    GFP_ATOMIC);
-               if (!hsdevp->llit[i]) {
-                       dev_err(ap->dev, "%s: dma_alloc_coherent failed\n",
-                                __func__);
-                       err = -ENOMEM;
-                       goto CLEANUP_ALLOC;
-               }
-       }
-
        if (ap->port_no == 0)  {
                dev_dbg(ap->dev, "%s: clearing TXCHEN, RXCHEN in DMAC\n",
                        __func__);
@@ -1377,22 +903,14 @@ CLEANUP:
 
 static void sata_dwc_port_stop(struct ata_port *ap)
 {
-       int i;
-       struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
        struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
 
        dev_dbg(ap->dev, "%s: ap->id = %d\n", __func__, ap->print_id);
 
-       if (hsdevp && hsdev) {
-               /* deallocate LLI table */
-               for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
-                       dma_free_coherent(ap->host->dev,
-                                         SATA_DWC_DMAC_LLI_TBL_SZ,
-                                        hsdevp->llit[i], hsdevp->llit_dma[i]);
-               }
+       dmaengine_terminate_all(hsdevp->chan);
+       dma_release_channel(hsdevp->chan);
 
-               kfree(hsdevp);
-       }
+       kfree(hsdevp);
        ap->private_data = NULL;
 }
 
@@ -1448,12 +966,12 @@ static void sata_dwc_bmdma_setup(struct ata_queued_cmd *qc)
 static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
 {
        int start_dma;
-       u32 reg, dma_chan;
+       u32 reg;
        struct sata_dwc_device *hsdev = HSDEV_FROM_QC(qc);
        struct ata_port *ap = qc->ap;
        struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+       struct dma_async_tx_descriptor *desc = hsdevp->desc[tag];
        int dir = qc->dma_dir;
-       dma_chan = hsdevp->dma_chan[tag];
 
        if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_NOT) {
                start_dma = 1;
@@ -1489,7 +1007,8 @@ static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
                                SATA_DWC_DMACR_RXCHEN);
 
                /* Enable AHB DMA transfer on the specified channel */
-               dma_dwc_xfer_start(dma_chan);
+               dmaengine_submit(desc);
+               dma_async_issue_pending(hsdevp->chan);
        }
 }
 
@@ -1515,26 +1034,21 @@ static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc)
  */
 static void sata_dwc_qc_prep_by_tag(struct ata_queued_cmd *qc, u8 tag)
 {
-       struct scatterlist *sg = qc->sg;
+       struct dma_async_tx_descriptor *desc;
        struct ata_port *ap = qc->ap;
-       int dma_chan;
-       struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
        struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
 
        dev_dbg(ap->dev, "%s: port=%d dma dir=%s n_elem=%d\n",
                __func__, ap->port_no, get_dma_dir_descript(qc->dma_dir),
                 qc->n_elem);
 
-       dma_chan = dma_dwc_xfer_setup(sg, qc->n_elem, hsdevp->llit[tag],
-                                     hsdevp->llit_dma[tag],
-                                     (void __iomem *)&hsdev->sata_dwc_regs->dmadr,
-                                     qc->dma_dir);
-       if (dma_chan < 0) {
-               dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns err %d\n",
-                       __func__, dma_chan);
+       desc = dma_dwc_xfer_setup(qc);
+       if (!desc) {
+               dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns NULL\n",
+                       __func__);
                return;
        }
-       hsdevp->dma_chan[tag] = dma_chan;
+       hsdevp->desc[tag] = desc;
 }
 
 static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)
@@ -1678,7 +1192,6 @@ static int sata_dwc_probe(struct platform_device *ofdev)
        struct ata_port_info pi = sata_dwc_port_info[0];
        const struct ata_port_info *ppi[] = { &pi, NULL };
        struct device_node *np = ofdev->dev.of_node;
-       u32 dma_chan;
 
        /* Allocate DWC SATA device */
        host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_DWC_MAX_PORTS);
@@ -1688,13 +1201,6 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 
        host->private_data = hsdev;
 
-       if (of_property_read_u32(np, "dma-channel", &dma_chan)) {
-               dev_warn(&ofdev->dev, "no dma-channel property set."
-                        " Use channel 0\n");
-               dma_chan = 0;
-       }
-       host_pvt.dma_channel = dma_chan;
-
        /* Ioremap SATA registers */
        base = of_iomap(np, 0);
        if (!base) {
@@ -1721,16 +1227,16 @@ static int sata_dwc_probe(struct platform_device *ofdev)
                   idr, ver[0], ver[1], ver[2]);
 
        /* Get SATA DMA interrupt number */
-       irq = irq_of_parse_and_map(np, 1);
-       if (irq == NO_IRQ) {
+       hsdev->dma->irq = irq_of_parse_and_map(np, 1);
+       if (hsdev->dma->irq == NO_IRQ) {
                dev_err(&ofdev->dev, "no SATA DMA irq\n");
                err = -ENODEV;
                goto error_iomap;
        }
 
        /* Get physical SATA DMA register base address */
-       host_pvt.sata_dma_regs = (void *)of_iomap(np, 1);
-       if (!(host_pvt.sata_dma_regs)) {
+       hsdev->dma->regs = of_iomap(np, 1);
+       if (!hsdev->dma->regs) {
                dev_err(&ofdev->dev,
                        "ioremap failed for AHBDMA register address\n");
                err = -ENODEV;
@@ -1740,8 +1246,10 @@ static int sata_dwc_probe(struct platform_device *ofdev)
        /* Save dev for later use in dev_xxx() routines */
        host_pvt.dwc_dev = &ofdev->dev;
 
+       hsdev->dma->dev = &ofdev->dev;
+
        /* Initialize AHB DMAC */
-       err = dma_dwc_init(hsdev, irq);
+       err = dw_dma_probe(hsdev->dma, NULL);
        if (err)
                goto error_dma_iomap;
 
@@ -1770,9 +1278,9 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 
 error_out:
        /* Free SATA DMA resources */
-       dma_dwc_exit(hsdev);
+       dw_dma_remove(hsdev->dma);
 error_dma_iomap:
-       iounmap((void __iomem *)host_pvt.sata_dma_regs);
+       iounmap(hsdev->dma->regs);
 error_iomap:
        iounmap(base);
        return err;
@@ -1787,9 +1295,9 @@ static int sata_dwc_remove(struct platform_device *ofdev)
        ata_host_detach(host);
 
        /* Free SATA DMA resources */
-       dma_dwc_exit(hsdev);
+       dw_dma_remove(hsdev->dma);
 
-       iounmap((void __iomem *)host_pvt.sata_dma_regs);
+       iounmap(hsdev->dma->regs);
        iounmap(hsdev->reg_base);
        dev_dbg(&ofdev->dev, "done\n");
        return 0;