dmaengine: Add Arm DMA-350 driver
authorRobin Murphy <robin.murphy@arm.com>
Wed, 12 Mar 2025 12:05:10 +0000 (12:05 +0000)
committerVinod Koul <vkoul@kernel.org>
Thu, 17 Apr 2025 15:17:39 +0000 (20:47 +0530)
Add an initial driver for the Arm Corelink DMA-350 controller, to
support basic mem-to-mem async_tx. The design here leaves room for more
fun things like peripheral support and scatter-gather chaining to come
in future.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/6d7d8efefa935d34977b59a74797ab377528db94.1741780808.git.robin.murphy@arm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/dma/Kconfig
drivers/dma/Makefile
drivers/dma/arm-dma350.c [new file with mode: 0644]

index df2d2dc00a0579d6bee49900aaf7deb4fdf3b88c..8109f73baf10fc3bbfe3dbf914b99a7337132ad0 100644 (file)
@@ -93,6 +93,13 @@ config APPLE_ADMAC
        help
          Enable support for Audio DMA Controller found on Apple Silicon SoCs.
 
+config ARM_DMA350
+       tristate "Arm DMA-350 support"
+       select DMA_ENGINE
+       select DMA_VIRTUAL_CHANNELS
+       help
+         Enable support for the Arm DMA-350 controller.
+
 config AT_HDMAC
        tristate "Atmel AHB DMA support"
        depends on ARCH_AT91
index 19ba465011a6d5c0f207a5702204c49e7e64d71e..ba97326447529beb072774693d102f9c02ec0b84 100644 (file)
@@ -17,6 +17,7 @@ obj-$(CONFIG_ALTERA_MSGDMA) += altera-msgdma.o
 obj-$(CONFIG_AMBA_PL08X) += amba-pl08x.o
 obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
 obj-$(CONFIG_APPLE_ADMAC) += apple-admac.o
+obj-$(CONFIG_ARM_DMA350) += arm-dma350.o
 obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_AT_XDMAC) += at_xdmac.o
 obj-$(CONFIG_AXI_DMAC) += dma-axi-dmac.o
diff --git a/drivers/dma/arm-dma350.c b/drivers/dma/arm-dma350.c
new file mode 100644 (file)
index 0000000..9efe2ca
--- /dev/null
@@ -0,0 +1,660 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2024-2025 Arm Limited
+// Arm DMA-350 driver
+
+#include <linux/bitfield.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+#define DMAINFO                        0x0f00
+
+#define DMA_BUILDCFG0          0xb0
+#define DMA_CFG_DATA_WIDTH     GENMASK(18, 16)
+#define DMA_CFG_ADDR_WIDTH     GENMASK(15, 10)
+#define DMA_CFG_NUM_CHANNELS   GENMASK(9, 4)
+
+#define DMA_BUILDCFG1          0xb4
+#define DMA_CFG_NUM_TRIGGER_IN GENMASK(8, 0)
+
+#define IIDR                   0xc8
+#define IIDR_PRODUCTID         GENMASK(31, 20)
+#define IIDR_VARIANT           GENMASK(19, 16)
+#define IIDR_REVISION          GENMASK(15, 12)
+#define IIDR_IMPLEMENTER       GENMASK(11, 0)
+
+#define PRODUCTID_DMA350       0x3a0
+#define IMPLEMENTER_ARM                0x43b
+
+#define DMACH(n)               (0x1000 + 0x0100 * (n))
+
+#define CH_CMD                 0x00
+#define CH_CMD_RESUME          BIT(5)
+#define CH_CMD_PAUSE           BIT(4)
+#define CH_CMD_STOP            BIT(3)
+#define CH_CMD_DISABLE         BIT(2)
+#define CH_CMD_CLEAR           BIT(1)
+#define CH_CMD_ENABLE          BIT(0)
+
+#define CH_STATUS              0x04
+#define CH_STAT_RESUMEWAIT     BIT(21)
+#define CH_STAT_PAUSED         BIT(20)
+#define CH_STAT_STOPPED                BIT(19)
+#define CH_STAT_DISABLED       BIT(18)
+#define CH_STAT_ERR            BIT(17)
+#define CH_STAT_DONE           BIT(16)
+#define CH_STAT_INTR_ERR       BIT(1)
+#define CH_STAT_INTR_DONE      BIT(0)
+
+#define CH_INTREN              0x08
+#define CH_INTREN_ERR          BIT(1)
+#define CH_INTREN_DONE         BIT(0)
+
+#define CH_CTRL                        0x0c
+#define CH_CTRL_USEDESTRIGIN   BIT(26)
+#define CH_CTRL_USESRCTRIGIN   BIT(26)
+#define CH_CTRL_DONETYPE       GENMASK(23, 21)
+#define CH_CTRL_REGRELOADTYPE  GENMASK(20, 18)
+#define CH_CTRL_XTYPE          GENMASK(11, 9)
+#define CH_CTRL_TRANSIZE       GENMASK(2, 0)
+
+#define CH_SRCADDR             0x10
+#define CH_SRCADDRHI           0x14
+#define CH_DESADDR             0x18
+#define CH_DESADDRHI           0x1c
+#define CH_XSIZE               0x20
+#define CH_XSIZEHI             0x24
+#define CH_SRCTRANSCFG         0x28
+#define CH_DESTRANSCFG         0x2c
+#define CH_CFG_MAXBURSTLEN     GENMASK(19, 16)
+#define CH_CFG_PRIVATTR                BIT(11)
+#define CH_CFG_SHAREATTR       GENMASK(9, 8)
+#define CH_CFG_MEMATTR         GENMASK(7, 0)
+
+#define TRANSCFG_DEVICE                                        \
+       FIELD_PREP(CH_CFG_MAXBURSTLEN, 0xf) |           \
+       FIELD_PREP(CH_CFG_SHAREATTR, SHAREATTR_OSH) |   \
+       FIELD_PREP(CH_CFG_MEMATTR, MEMATTR_DEVICE)
+#define TRANSCFG_NC                                    \
+       FIELD_PREP(CH_CFG_MAXBURSTLEN, 0xf) |           \
+       FIELD_PREP(CH_CFG_SHAREATTR, SHAREATTR_OSH) |   \
+       FIELD_PREP(CH_CFG_MEMATTR, MEMATTR_NC)
+#define TRANSCFG_WB                                    \
+       FIELD_PREP(CH_CFG_MAXBURSTLEN, 0xf) |           \
+       FIELD_PREP(CH_CFG_SHAREATTR, SHAREATTR_ISH) |   \
+       FIELD_PREP(CH_CFG_MEMATTR, MEMATTR_WB)
+
+#define CH_XADDRINC            0x30
+#define CH_XY_DES              GENMASK(31, 16)
+#define CH_XY_SRC              GENMASK(15, 0)
+
+#define CH_FILLVAL             0x38
+#define CH_SRCTRIGINCFG                0x4c
+#define CH_DESTRIGINCFG                0x50
+#define CH_LINKATTR            0x70
+#define CH_LINK_SHAREATTR      GENMASK(9, 8)
+#define CH_LINK_MEMATTR                GENMASK(7, 0)
+
+#define CH_AUTOCFG             0x74
+#define CH_LINKADDR            0x78
+#define CH_LINKADDR_EN         BIT(0)
+
+#define CH_LINKADDRHI          0x7c
+#define CH_ERRINFO             0x90
+#define CH_ERRINFO_AXIRDPOISERR BIT(18)
+#define CH_ERRINFO_AXIWRRESPERR BIT(17)
+#define CH_ERRINFO_AXIRDRESPERR BIT(16)
+
+#define CH_BUILDCFG0           0xf8
+#define CH_CFG_INC_WIDTH       GENMASK(29, 26)
+#define CH_CFG_DATA_WIDTH      GENMASK(24, 22)
+#define CH_CFG_DATA_BUF_SIZE   GENMASK(7, 0)
+
+#define CH_BUILDCFG1           0xfc
+#define CH_CFG_HAS_CMDLINK     BIT(8)
+#define CH_CFG_HAS_TRIGSEL     BIT(7)
+#define CH_CFG_HAS_TRIGIN      BIT(5)
+#define CH_CFG_HAS_WRAP                BIT(1)
+
+
+#define LINK_REGCLEAR          BIT(0)
+#define LINK_INTREN            BIT(2)
+#define LINK_CTRL              BIT(3)
+#define LINK_SRCADDR           BIT(4)
+#define LINK_SRCADDRHI         BIT(5)
+#define LINK_DESADDR           BIT(6)
+#define LINK_DESADDRHI         BIT(7)
+#define LINK_XSIZE             BIT(8)
+#define LINK_XSIZEHI           BIT(9)
+#define LINK_SRCTRANSCFG       BIT(10)
+#define LINK_DESTRANSCFG       BIT(11)
+#define LINK_XADDRINC          BIT(12)
+#define LINK_FILLVAL           BIT(14)
+#define LINK_SRCTRIGINCFG      BIT(19)
+#define LINK_DESTRIGINCFG      BIT(20)
+#define LINK_AUTOCFG           BIT(29)
+#define LINK_LINKADDR          BIT(30)
+#define LINK_LINKADDRHI                BIT(31)
+
+
+enum ch_ctrl_donetype {
+       CH_CTRL_DONETYPE_NONE = 0,
+       CH_CTRL_DONETYPE_CMD = 1,
+       CH_CTRL_DONETYPE_CYCLE = 3
+};
+
+enum ch_ctrl_xtype {
+       CH_CTRL_XTYPE_DISABLE = 0,
+       CH_CTRL_XTYPE_CONTINUE = 1,
+       CH_CTRL_XTYPE_WRAP = 2,
+       CH_CTRL_XTYPE_FILL = 3
+};
+
+enum ch_cfg_shareattr {
+       SHAREATTR_NSH = 0,
+       SHAREATTR_OSH = 2,
+       SHAREATTR_ISH = 3
+};
+
+enum ch_cfg_memattr {
+       MEMATTR_DEVICE = 0x00,
+       MEMATTR_NC = 0x44,
+       MEMATTR_WB = 0xff
+};
+
+struct d350_desc {
+       struct virt_dma_desc vd;
+       u32 command[16];
+       u16 xsize;
+       u16 xsizehi;
+       u8 tsz;
+};
+
+struct d350_chan {
+       struct virt_dma_chan vc;
+       struct d350_desc *desc;
+       void __iomem *base;
+       int irq;
+       enum dma_status status;
+       dma_cookie_t cookie;
+       u32 residue;
+       u8 tsz;
+       bool has_trig;
+       bool has_wrap;
+       bool coherent;
+};
+
+struct d350 {
+       struct dma_device dma;
+       int nchan;
+       int nreq;
+       struct d350_chan channels[] __counted_by(nchan);
+};
+
+static inline struct d350_chan *to_d350_chan(struct dma_chan *chan)
+{
+       return container_of(chan, struct d350_chan, vc.chan);
+}
+
+static inline struct d350_desc *to_d350_desc(struct virt_dma_desc *vd)
+{
+       return container_of(vd, struct d350_desc, vd);
+}
+
+static void d350_desc_free(struct virt_dma_desc *vd)
+{
+       kfree(to_d350_desc(vd));
+}
+
+static struct dma_async_tx_descriptor *d350_prep_memcpy(struct dma_chan *chan,
+               dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       struct d350_desc *desc;
+       u32 *cmd;
+
+       desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+       if (!desc)
+               return NULL;
+
+       desc->tsz = __ffs(len | dest | src | (1 << dch->tsz));
+       desc->xsize = lower_16_bits(len >> desc->tsz);
+       desc->xsizehi = upper_16_bits(len >> desc->tsz);
+
+       cmd = desc->command;
+       cmd[0] = LINK_CTRL | LINK_SRCADDR | LINK_SRCADDRHI | LINK_DESADDR |
+                LINK_DESADDRHI | LINK_XSIZE | LINK_XSIZEHI | LINK_SRCTRANSCFG |
+                LINK_DESTRANSCFG | LINK_XADDRINC | LINK_LINKADDR;
+
+       cmd[1] = FIELD_PREP(CH_CTRL_TRANSIZE, desc->tsz) |
+                FIELD_PREP(CH_CTRL_XTYPE, CH_CTRL_XTYPE_CONTINUE) |
+                FIELD_PREP(CH_CTRL_DONETYPE, CH_CTRL_DONETYPE_CMD);
+
+       cmd[2] = lower_32_bits(src);
+       cmd[3] = upper_32_bits(src);
+       cmd[4] = lower_32_bits(dest);
+       cmd[5] = upper_32_bits(dest);
+       cmd[6] = FIELD_PREP(CH_XY_SRC, desc->xsize) | FIELD_PREP(CH_XY_DES, desc->xsize);
+       cmd[7] = FIELD_PREP(CH_XY_SRC, desc->xsizehi) | FIELD_PREP(CH_XY_DES, desc->xsizehi);
+       cmd[8] = dch->coherent ? TRANSCFG_WB : TRANSCFG_NC;
+       cmd[9] = dch->coherent ? TRANSCFG_WB : TRANSCFG_NC;
+       cmd[10] = FIELD_PREP(CH_XY_SRC, 1) | FIELD_PREP(CH_XY_DES, 1);
+       cmd[11] = 0;
+
+       return vchan_tx_prep(&dch->vc, &desc->vd, flags);
+}
+
+static struct dma_async_tx_descriptor *d350_prep_memset(struct dma_chan *chan,
+               dma_addr_t dest, int value, size_t len, unsigned long flags)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       struct d350_desc *desc;
+       u32 *cmd;
+
+       desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+       if (!desc)
+               return NULL;
+
+       desc->tsz = __ffs(len | dest | (1 << dch->tsz));
+       desc->xsize = lower_16_bits(len >> desc->tsz);
+       desc->xsizehi = upper_16_bits(len >> desc->tsz);
+
+       cmd = desc->command;
+       cmd[0] = LINK_CTRL | LINK_DESADDR | LINK_DESADDRHI |
+                LINK_XSIZE | LINK_XSIZEHI | LINK_DESTRANSCFG |
+                LINK_XADDRINC | LINK_FILLVAL | LINK_LINKADDR;
+
+       cmd[1] = FIELD_PREP(CH_CTRL_TRANSIZE, desc->tsz) |
+                FIELD_PREP(CH_CTRL_XTYPE, CH_CTRL_XTYPE_FILL) |
+                FIELD_PREP(CH_CTRL_DONETYPE, CH_CTRL_DONETYPE_CMD);
+
+       cmd[2] = lower_32_bits(dest);
+       cmd[3] = upper_32_bits(dest);
+       cmd[4] = FIELD_PREP(CH_XY_DES, desc->xsize);
+       cmd[5] = FIELD_PREP(CH_XY_DES, desc->xsizehi);
+       cmd[6] = dch->coherent ? TRANSCFG_WB : TRANSCFG_NC;
+       cmd[7] = FIELD_PREP(CH_XY_DES, 1);
+       cmd[8] = (u8)value * 0x01010101;
+       cmd[9] = 0;
+
+       return vchan_tx_prep(&dch->vc, &desc->vd, flags);
+}
+
+static int d350_pause(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&dch->vc.lock, flags);
+       if (dch->status == DMA_IN_PROGRESS) {
+               writel_relaxed(CH_CMD_PAUSE, dch->base + CH_CMD);
+               dch->status = DMA_PAUSED;
+       }
+       spin_unlock_irqrestore(&dch->vc.lock, flags);
+
+       return 0;
+}
+
+static int d350_resume(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&dch->vc.lock, flags);
+       if (dch->status == DMA_PAUSED) {
+               writel_relaxed(CH_CMD_RESUME, dch->base + CH_CMD);
+               dch->status = DMA_IN_PROGRESS;
+       }
+       spin_unlock_irqrestore(&dch->vc.lock, flags);
+
+       return 0;
+}
+
+static u32 d350_get_residue(struct d350_chan *dch)
+{
+       u32 res, xsize, xsizehi, hi_new;
+       int retries = 3; /* 1st time unlucky, 2nd improbable, 3rd just broken */
+
+       hi_new = readl_relaxed(dch->base + CH_XSIZEHI);
+       do {
+               xsizehi = hi_new;
+               xsize = readl_relaxed(dch->base + CH_XSIZE);
+               hi_new = readl_relaxed(dch->base + CH_XSIZEHI);
+       } while (xsizehi != hi_new && --retries);
+
+       res = FIELD_GET(CH_XY_DES, xsize);
+       res |= FIELD_GET(CH_XY_DES, xsizehi) << 16;
+
+       return res << dch->desc->tsz;
+}
+
+static int d350_terminate_all(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       unsigned long flags;
+       LIST_HEAD(list);
+
+       spin_lock_irqsave(&dch->vc.lock, flags);
+       writel_relaxed(CH_CMD_STOP, dch->base + CH_CMD);
+       if (dch->desc) {
+               if (dch->status != DMA_ERROR)
+                       vchan_terminate_vdesc(&dch->desc->vd);
+               dch->desc = NULL;
+               dch->status = DMA_COMPLETE;
+       }
+       vchan_get_all_descriptors(&dch->vc, &list);
+       list_splice_tail(&list, &dch->vc.desc_terminated);
+       spin_unlock_irqrestore(&dch->vc.lock, flags);
+
+       return 0;
+}
+
+static void d350_synchronize(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+
+       vchan_synchronize(&dch->vc);
+}
+
+static u32 d350_desc_bytes(struct d350_desc *desc)
+{
+       return ((u32)desc->xsizehi << 16 | desc->xsize) << desc->tsz;
+}
+
+static enum dma_status d350_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+                                     struct dma_tx_state *state)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       struct virt_dma_desc *vd;
+       enum dma_status status;
+       unsigned long flags;
+       u32 residue = 0;
+
+       status = dma_cookie_status(chan, cookie, state);
+
+       spin_lock_irqsave(&dch->vc.lock, flags);
+       if (cookie == dch->cookie) {
+               status = dch->status;
+               if (status == DMA_IN_PROGRESS || status == DMA_PAUSED)
+                       dch->residue = d350_get_residue(dch);
+               residue = dch->residue;
+       } else if ((vd = vchan_find_desc(&dch->vc, cookie))) {
+               residue = d350_desc_bytes(to_d350_desc(vd));
+       } else if (status == DMA_IN_PROGRESS) {
+               /* Somebody else terminated it? */
+               status = DMA_ERROR;
+       }
+       spin_unlock_irqrestore(&dch->vc.lock, flags);
+
+       dma_set_residue(state, residue);
+       return status;
+}
+
+static void d350_start_next(struct d350_chan *dch)
+{
+       u32 hdr, *reg;
+
+       dch->desc = to_d350_desc(vchan_next_desc(&dch->vc));
+       if (!dch->desc)
+               return;
+
+       list_del(&dch->desc->vd.node);
+       dch->status = DMA_IN_PROGRESS;
+       dch->cookie = dch->desc->vd.tx.cookie;
+       dch->residue = d350_desc_bytes(dch->desc);
+
+       hdr = dch->desc->command[0];
+       reg = &dch->desc->command[1];
+
+       if (hdr & LINK_INTREN)
+               writel_relaxed(*reg++, dch->base + CH_INTREN);
+       if (hdr & LINK_CTRL)
+               writel_relaxed(*reg++, dch->base + CH_CTRL);
+       if (hdr & LINK_SRCADDR)
+               writel_relaxed(*reg++, dch->base + CH_SRCADDR);
+       if (hdr & LINK_SRCADDRHI)
+               writel_relaxed(*reg++, dch->base + CH_SRCADDRHI);
+       if (hdr & LINK_DESADDR)
+               writel_relaxed(*reg++, dch->base + CH_DESADDR);
+       if (hdr & LINK_DESADDRHI)
+               writel_relaxed(*reg++, dch->base + CH_DESADDRHI);
+       if (hdr & LINK_XSIZE)
+               writel_relaxed(*reg++, dch->base + CH_XSIZE);
+       if (hdr & LINK_XSIZEHI)
+               writel_relaxed(*reg++, dch->base + CH_XSIZEHI);
+       if (hdr & LINK_SRCTRANSCFG)
+               writel_relaxed(*reg++, dch->base + CH_SRCTRANSCFG);
+       if (hdr & LINK_DESTRANSCFG)
+               writel_relaxed(*reg++, dch->base + CH_DESTRANSCFG);
+       if (hdr & LINK_XADDRINC)
+               writel_relaxed(*reg++, dch->base + CH_XADDRINC);
+       if (hdr & LINK_FILLVAL)
+               writel_relaxed(*reg++, dch->base + CH_FILLVAL);
+       if (hdr & LINK_SRCTRIGINCFG)
+               writel_relaxed(*reg++, dch->base + CH_SRCTRIGINCFG);
+       if (hdr & LINK_DESTRIGINCFG)
+               writel_relaxed(*reg++, dch->base + CH_DESTRIGINCFG);
+       if (hdr & LINK_AUTOCFG)
+               writel_relaxed(*reg++, dch->base + CH_AUTOCFG);
+       if (hdr & LINK_LINKADDR)
+               writel_relaxed(*reg++, dch->base + CH_LINKADDR);
+       if (hdr & LINK_LINKADDRHI)
+               writel_relaxed(*reg++, dch->base + CH_LINKADDRHI);
+
+       writel(CH_CMD_ENABLE, dch->base + CH_CMD);
+}
+
+static void d350_issue_pending(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       unsigned long flags;
+
+       spin_lock_irqsave(&dch->vc.lock, flags);
+       if (vchan_issue_pending(&dch->vc) && !dch->desc)
+               d350_start_next(dch);
+       spin_unlock_irqrestore(&dch->vc.lock, flags);
+}
+
+static irqreturn_t d350_irq(int irq, void *data)
+{
+       struct d350_chan *dch = data;
+       struct device *dev = dch->vc.chan.device->dev;
+       struct virt_dma_desc *vd = &dch->desc->vd;
+       u32 ch_status;
+
+       ch_status = readl(dch->base + CH_STATUS);
+       if (!ch_status)
+               return IRQ_NONE;
+
+       if (ch_status & CH_STAT_INTR_ERR) {
+               u32 errinfo = readl_relaxed(dch->base + CH_ERRINFO);
+
+               if (errinfo & (CH_ERRINFO_AXIRDPOISERR | CH_ERRINFO_AXIRDRESPERR))
+                       vd->tx_result.result = DMA_TRANS_READ_FAILED;
+               else if (errinfo & CH_ERRINFO_AXIWRRESPERR)
+                       vd->tx_result.result = DMA_TRANS_WRITE_FAILED;
+               else
+                       vd->tx_result.result = DMA_TRANS_ABORTED;
+
+               vd->tx_result.residue = d350_get_residue(dch);
+       } else if (!(ch_status & CH_STAT_INTR_DONE)) {
+               dev_warn(dev, "Unexpected IRQ source? 0x%08x\n", ch_status);
+       }
+       writel_relaxed(ch_status, dch->base + CH_STATUS);
+
+       spin_lock(&dch->vc.lock);
+       vchan_cookie_complete(vd);
+       if (ch_status & CH_STAT_INTR_DONE) {
+               dch->status = DMA_COMPLETE;
+               dch->residue = 0;
+               d350_start_next(dch);
+       } else {
+               dch->status = DMA_ERROR;
+               dch->residue = vd->tx_result.residue;
+       }
+       spin_unlock(&dch->vc.lock);
+
+       return IRQ_HANDLED;
+}
+
+static int d350_alloc_chan_resources(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+       int ret = request_irq(dch->irq, d350_irq, IRQF_SHARED,
+                             dev_name(&dch->vc.chan.dev->device), dch);
+       if (!ret)
+               writel_relaxed(CH_INTREN_DONE | CH_INTREN_ERR, dch->base + CH_INTREN);
+
+       return ret;
+}
+
+static void d350_free_chan_resources(struct dma_chan *chan)
+{
+       struct d350_chan *dch = to_d350_chan(chan);
+
+       writel_relaxed(0, dch->base + CH_INTREN);
+       free_irq(dch->irq, dch);
+       vchan_free_chan_resources(&dch->vc);
+}
+
+static int d350_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct d350 *dmac;
+       void __iomem *base;
+       u32 reg;
+       int ret, nchan, dw, aw, r, p;
+       bool coherent, memset;
+
+       base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(base))
+               return PTR_ERR(base);
+
+       reg = readl_relaxed(base + DMAINFO + IIDR);
+       r = FIELD_GET(IIDR_VARIANT, reg);
+       p = FIELD_GET(IIDR_REVISION, reg);
+       if (FIELD_GET(IIDR_IMPLEMENTER, reg) != IMPLEMENTER_ARM ||
+           FIELD_GET(IIDR_PRODUCTID, reg) != PRODUCTID_DMA350)
+               return dev_err_probe(dev, -ENODEV, "Not a DMA-350!");
+
+       reg = readl_relaxed(base + DMAINFO + DMA_BUILDCFG0);
+       nchan = FIELD_GET(DMA_CFG_NUM_CHANNELS, reg) + 1;
+       dw = 1 << FIELD_GET(DMA_CFG_DATA_WIDTH, reg);
+       aw = FIELD_GET(DMA_CFG_ADDR_WIDTH, reg) + 1;
+
+       dma_set_mask_and_coherent(dev, DMA_BIT_MASK(aw));
+       coherent = device_get_dma_attr(dev) == DEV_DMA_COHERENT;
+
+       dmac = devm_kzalloc(dev, struct_size(dmac, channels, nchan), GFP_KERNEL);
+       if (!dmac)
+               return -ENOMEM;
+
+       dmac->nchan = nchan;
+
+       reg = readl_relaxed(base + DMAINFO + DMA_BUILDCFG1);
+       dmac->nreq = FIELD_GET(DMA_CFG_NUM_TRIGGER_IN, reg);
+
+       dev_dbg(dev, "DMA-350 r%dp%d with %d channels, %d requests\n", r, p, dmac->nchan, dmac->nreq);
+
+       dmac->dma.dev = dev;
+       for (int i = min(dw, 16); i > 0; i /= 2) {
+               dmac->dma.src_addr_widths |= BIT(i);
+               dmac->dma.dst_addr_widths |= BIT(i);
+       }
+       dmac->dma.directions = BIT(DMA_MEM_TO_MEM);
+       dmac->dma.descriptor_reuse = true;
+       dmac->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+       dmac->dma.device_alloc_chan_resources = d350_alloc_chan_resources;
+       dmac->dma.device_free_chan_resources = d350_free_chan_resources;
+       dma_cap_set(DMA_MEMCPY, dmac->dma.cap_mask);
+       dmac->dma.device_prep_dma_memcpy = d350_prep_memcpy;
+       dmac->dma.device_pause = d350_pause;
+       dmac->dma.device_resume = d350_resume;
+       dmac->dma.device_terminate_all = d350_terminate_all;
+       dmac->dma.device_synchronize = d350_synchronize;
+       dmac->dma.device_tx_status = d350_tx_status;
+       dmac->dma.device_issue_pending = d350_issue_pending;
+       INIT_LIST_HEAD(&dmac->dma.channels);
+
+       /* Would be nice to have per-channel caps for this... */
+       memset = true;
+       for (int i = 0; i < nchan; i++) {
+               struct d350_chan *dch = &dmac->channels[i];
+
+               dch->base = base + DMACH(i);
+               writel_relaxed(CH_CMD_CLEAR, dch->base + CH_CMD);
+
+               reg = readl_relaxed(dch->base + CH_BUILDCFG1);
+               if (!(FIELD_GET(CH_CFG_HAS_CMDLINK, reg))) {
+                       dev_warn(dev, "No command link support on channel %d\n", i);
+                       continue;
+               }
+               dch->irq = platform_get_irq(pdev, i);
+               if (dch->irq < 0)
+                       return dev_err_probe(dev, dch->irq,
+                                            "Failed to get IRQ for channel %d\n", i);
+
+               dch->has_wrap = FIELD_GET(CH_CFG_HAS_WRAP, reg);
+               dch->has_trig = FIELD_GET(CH_CFG_HAS_TRIGIN, reg) &
+                               FIELD_GET(CH_CFG_HAS_TRIGSEL, reg);
+
+               /* Fill is a special case of Wrap */
+               memset &= dch->has_wrap;
+
+               reg = readl_relaxed(dch->base + CH_BUILDCFG0);
+               dch->tsz = FIELD_GET(CH_CFG_DATA_WIDTH, reg);
+
+               reg = FIELD_PREP(CH_LINK_SHAREATTR, coherent ? SHAREATTR_ISH : SHAREATTR_OSH);
+               reg |= FIELD_PREP(CH_LINK_MEMATTR, coherent ? MEMATTR_WB : MEMATTR_NC);
+               writel_relaxed(reg, dch->base + CH_LINKATTR);
+
+               dch->vc.desc_free = d350_desc_free;
+               vchan_init(&dch->vc, &dmac->dma);
+       }
+
+       if (memset) {
+               dma_cap_set(DMA_MEMSET, dmac->dma.cap_mask);
+               dmac->dma.device_prep_dma_memset = d350_prep_memset;
+       }
+
+       platform_set_drvdata(pdev, dmac);
+
+       ret = dma_async_device_register(&dmac->dma);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to register DMA device\n");
+
+       return 0;
+}
+
+static void d350_remove(struct platform_device *pdev)
+{
+       struct d350 *dmac = platform_get_drvdata(pdev);
+
+       dma_async_device_unregister(&dmac->dma);
+}
+
+static const struct of_device_id d350_of_match[] __maybe_unused = {
+       { .compatible = "arm,dma-350" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, d350_of_match);
+
+static struct platform_driver d350_driver = {
+       .driver = {
+               .name = "arm-dma350",
+               .of_match_table = of_match_ptr(d350_of_match),
+       },
+       .probe = d350_probe,
+       .remove = d350_remove,
+};
+module_platform_driver(d350_driver);
+
+MODULE_AUTHOR("Robin Murphy <robin.murphy@arm.com>");
+MODULE_DESCRIPTION("Arm DMA-350 driver");
+MODULE_LICENSE("GPL v2");