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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/dma/moxart-dma.c
Initial import
Diffstat (limited to 'drivers/dma/moxart-dma.c')
-rw-r--r--drivers/dma/moxart-dma.c679
1 files changed, 679 insertions, 0 deletions
diff --git a/drivers/dma/moxart-dma.c b/drivers/dma/moxart-dma.c
new file mode 100644
index 000000000..b4634109e
--- /dev/null
+++ b/drivers/dma/moxart-dma.c
@@ -0,0 +1,679 @@
+/*
+ * MOXA ART SoCs DMA Engine support.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_dma.h>
+#include <linux/bitops.h>
+
+#include <asm/cacheflush.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+#define APB_DMA_MAX_CHANNEL 4
+
+#define REG_OFF_ADDRESS_SOURCE 0
+#define REG_OFF_ADDRESS_DEST 4
+#define REG_OFF_CYCLES 8
+#define REG_OFF_CTRL 12
+#define REG_OFF_CHAN_SIZE 16
+
+#define APB_DMA_ENABLE BIT(0)
+#define APB_DMA_FIN_INT_STS BIT(1)
+#define APB_DMA_FIN_INT_EN BIT(2)
+#define APB_DMA_BURST_MODE BIT(3)
+#define APB_DMA_ERR_INT_STS BIT(4)
+#define APB_DMA_ERR_INT_EN BIT(5)
+
+/*
+ * Unset: APB
+ * Set: AHB
+ */
+#define APB_DMA_SOURCE_SELECT 0x40
+#define APB_DMA_DEST_SELECT 0x80
+
+#define APB_DMA_SOURCE 0x100
+#define APB_DMA_DEST 0x1000
+
+#define APB_DMA_SOURCE_MASK 0x700
+#define APB_DMA_DEST_MASK 0x7000
+
+/*
+ * 000: No increment
+ * 001: +1 (Burst=0), +4 (Burst=1)
+ * 010: +2 (Burst=0), +8 (Burst=1)
+ * 011: +4 (Burst=0), +16 (Burst=1)
+ * 101: -1 (Burst=0), -4 (Burst=1)
+ * 110: -2 (Burst=0), -8 (Burst=1)
+ * 111: -4 (Burst=0), -16 (Burst=1)
+ */
+#define APB_DMA_SOURCE_INC_0 0
+#define APB_DMA_SOURCE_INC_1_4 0x100
+#define APB_DMA_SOURCE_INC_2_8 0x200
+#define APB_DMA_SOURCE_INC_4_16 0x300
+#define APB_DMA_SOURCE_DEC_1_4 0x500
+#define APB_DMA_SOURCE_DEC_2_8 0x600
+#define APB_DMA_SOURCE_DEC_4_16 0x700
+#define APB_DMA_DEST_INC_0 0
+#define APB_DMA_DEST_INC_1_4 0x1000
+#define APB_DMA_DEST_INC_2_8 0x2000
+#define APB_DMA_DEST_INC_4_16 0x3000
+#define APB_DMA_DEST_DEC_1_4 0x5000
+#define APB_DMA_DEST_DEC_2_8 0x6000
+#define APB_DMA_DEST_DEC_4_16 0x7000
+
+/*
+ * Request signal select source/destination address for DMA hardware handshake.
+ *
+ * The request line number is a property of the DMA controller itself,
+ * e.g. MMC must always request channels where dma_slave_config->slave_id is 5.
+ *
+ * 0: No request / Grant signal
+ * 1-15: Request / Grant signal
+ */
+#define APB_DMA_SOURCE_REQ_NO 0x1000000
+#define APB_DMA_SOURCE_REQ_NO_MASK 0xf000000
+#define APB_DMA_DEST_REQ_NO 0x10000
+#define APB_DMA_DEST_REQ_NO_MASK 0xf0000
+
+#define APB_DMA_DATA_WIDTH 0x100000
+#define APB_DMA_DATA_WIDTH_MASK 0x300000
+/*
+ * Data width of transfer:
+ *
+ * 00: Word
+ * 01: Half
+ * 10: Byte
+ */
+#define APB_DMA_DATA_WIDTH_4 0
+#define APB_DMA_DATA_WIDTH_2 0x100000
+#define APB_DMA_DATA_WIDTH_1 0x200000
+
+#define APB_DMA_CYCLES_MASK 0x00ffffff
+
+#define MOXART_DMA_DATA_TYPE_S8 0x00
+#define MOXART_DMA_DATA_TYPE_S16 0x01
+#define MOXART_DMA_DATA_TYPE_S32 0x02
+
+struct moxart_sg {
+ dma_addr_t addr;
+ uint32_t len;
+};
+
+struct moxart_desc {
+ enum dma_transfer_direction dma_dir;
+ dma_addr_t dev_addr;
+ unsigned int sglen;
+ unsigned int dma_cycles;
+ struct virt_dma_desc vd;
+ uint8_t es;
+ struct moxart_sg sg[0];
+};
+
+struct moxart_chan {
+ struct virt_dma_chan vc;
+
+ void __iomem *base;
+ struct moxart_desc *desc;
+
+ struct dma_slave_config cfg;
+
+ bool allocated;
+ bool error;
+ int ch_num;
+ unsigned int line_reqno;
+ unsigned int sgidx;
+};
+
+struct moxart_dmadev {
+ struct dma_device dma_slave;
+ struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL];
+};
+
+struct moxart_filter_data {
+ struct moxart_dmadev *mdc;
+ struct of_phandle_args *dma_spec;
+};
+
+static const unsigned int es_bytes[] = {
+ [MOXART_DMA_DATA_TYPE_S8] = 1,
+ [MOXART_DMA_DATA_TYPE_S16] = 2,
+ [MOXART_DMA_DATA_TYPE_S32] = 4,
+};
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+ return &chan->dev->device;
+}
+
+static inline struct moxart_chan *to_moxart_dma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct moxart_chan, vc.chan);
+}
+
+static inline struct moxart_desc *to_moxart_dma_desc(
+ struct dma_async_tx_descriptor *t)
+{
+ return container_of(t, struct moxart_desc, vd.tx);
+}
+
+static void moxart_dma_desc_free(struct virt_dma_desc *vd)
+{
+ kfree(container_of(vd, struct moxart_desc, vd));
+}
+
+static int moxart_terminate_all(struct dma_chan *chan)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ unsigned long flags;
+ LIST_HEAD(head);
+ u32 ctrl;
+
+ dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch);
+
+ spin_lock_irqsave(&ch->vc.lock, flags);
+
+ if (ch->desc) {
+ moxart_dma_desc_free(&ch->desc->vd);
+ ch->desc = NULL;
+ }
+
+ ctrl = readl(ch->base + REG_OFF_CTRL);
+ ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
+ writel(ctrl, ch->base + REG_OFF_CTRL);
+
+ vchan_get_all_descriptors(&ch->vc, &head);
+ spin_unlock_irqrestore(&ch->vc.lock, flags);
+ vchan_dma_desc_free_list(&ch->vc, &head);
+
+ return 0;
+}
+
+static int moxart_slave_config(struct dma_chan *chan,
+ struct dma_slave_config *cfg)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ u32 ctrl;
+
+ ch->cfg = *cfg;
+
+ ctrl = readl(ch->base + REG_OFF_CTRL);
+ ctrl |= APB_DMA_BURST_MODE;
+ ctrl &= ~(APB_DMA_DEST_MASK | APB_DMA_SOURCE_MASK);
+ ctrl &= ~(APB_DMA_DEST_REQ_NO_MASK | APB_DMA_SOURCE_REQ_NO_MASK);
+
+ switch (ch->cfg.src_addr_width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ ctrl |= APB_DMA_DATA_WIDTH_1;
+ if (ch->cfg.direction != DMA_MEM_TO_DEV)
+ ctrl |= APB_DMA_DEST_INC_1_4;
+ else
+ ctrl |= APB_DMA_SOURCE_INC_1_4;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ ctrl |= APB_DMA_DATA_WIDTH_2;
+ if (ch->cfg.direction != DMA_MEM_TO_DEV)
+ ctrl |= APB_DMA_DEST_INC_2_8;
+ else
+ ctrl |= APB_DMA_SOURCE_INC_2_8;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ ctrl &= ~APB_DMA_DATA_WIDTH;
+ if (ch->cfg.direction != DMA_MEM_TO_DEV)
+ ctrl |= APB_DMA_DEST_INC_4_16;
+ else
+ ctrl |= APB_DMA_SOURCE_INC_4_16;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (ch->cfg.direction == DMA_MEM_TO_DEV) {
+ ctrl &= ~APB_DMA_DEST_SELECT;
+ ctrl |= APB_DMA_SOURCE_SELECT;
+ ctrl |= (ch->line_reqno << 16 &
+ APB_DMA_DEST_REQ_NO_MASK);
+ } else {
+ ctrl |= APB_DMA_DEST_SELECT;
+ ctrl &= ~APB_DMA_SOURCE_SELECT;
+ ctrl |= (ch->line_reqno << 24 &
+ APB_DMA_SOURCE_REQ_NO_MASK);
+ }
+
+ writel(ctrl, ch->base + REG_OFF_CTRL);
+
+ return 0;
+}
+
+static struct dma_async_tx_descriptor *moxart_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_transfer_direction dir,
+ unsigned long tx_flags, void *context)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ struct moxart_desc *d;
+ enum dma_slave_buswidth dev_width;
+ dma_addr_t dev_addr;
+ struct scatterlist *sgent;
+ unsigned int es;
+ unsigned int i;
+
+ if (!is_slave_direction(dir)) {
+ dev_err(chan2dev(chan), "%s: invalid DMA direction\n",
+ __func__);
+ return NULL;
+ }
+
+ if (dir == DMA_DEV_TO_MEM) {
+ dev_addr = ch->cfg.src_addr;
+ dev_width = ch->cfg.src_addr_width;
+ } else {
+ dev_addr = ch->cfg.dst_addr;
+ dev_width = ch->cfg.dst_addr_width;
+ }
+
+ switch (dev_width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ es = MOXART_DMA_DATA_TYPE_S8;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ es = MOXART_DMA_DATA_TYPE_S16;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ es = MOXART_DMA_DATA_TYPE_S32;
+ break;
+ default:
+ dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n",
+ __func__, dev_width);
+ return NULL;
+ }
+
+ d = kzalloc(sizeof(*d) + sg_len * sizeof(d->sg[0]), GFP_ATOMIC);
+ if (!d)
+ return NULL;
+
+ d->dma_dir = dir;
+ d->dev_addr = dev_addr;
+ d->es = es;
+
+ for_each_sg(sgl, sgent, sg_len, i) {
+ d->sg[i].addr = sg_dma_address(sgent);
+ d->sg[i].len = sg_dma_len(sgent);
+ }
+
+ d->sglen = sg_len;
+
+ ch->error = 0;
+
+ return vchan_tx_prep(&ch->vc, &d->vd, tx_flags);
+}
+
+static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct moxart_dmadev *mdc = ofdma->of_dma_data;
+ struct dma_chan *chan;
+ struct moxart_chan *ch;
+
+ chan = dma_get_any_slave_channel(&mdc->dma_slave);
+ if (!chan)
+ return NULL;
+
+ ch = to_moxart_dma_chan(chan);
+ ch->line_reqno = dma_spec->args[0];
+
+ return chan;
+}
+
+static int moxart_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+
+ dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n",
+ __func__, ch->ch_num);
+ ch->allocated = 1;
+
+ return 0;
+}
+
+static void moxart_free_chan_resources(struct dma_chan *chan)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+
+ vchan_free_chan_resources(&ch->vc);
+
+ dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n",
+ __func__, ch->ch_num);
+ ch->allocated = 0;
+}
+
+static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr,
+ dma_addr_t dst_addr)
+{
+ writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE);
+ writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST);
+}
+
+static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len)
+{
+ struct moxart_desc *d = ch->desc;
+ unsigned int sglen_div = es_bytes[d->es];
+
+ d->dma_cycles = len >> sglen_div;
+
+ /*
+ * There are 4 cycles on 64 bytes copied, i.e. one cycle copies 16
+ * bytes ( when width is APB_DMAB_DATA_WIDTH_4 ).
+ */
+ writel(d->dma_cycles, ch->base + REG_OFF_CYCLES);
+
+ dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n",
+ __func__, d->dma_cycles, len);
+}
+
+static void moxart_start_dma(struct moxart_chan *ch)
+{
+ u32 ctrl;
+
+ ctrl = readl(ch->base + REG_OFF_CTRL);
+ ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
+ writel(ctrl, ch->base + REG_OFF_CTRL);
+}
+
+static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx)
+{
+ struct moxart_desc *d = ch->desc;
+ struct moxart_sg *sg = ch->desc->sg + idx;
+
+ if (ch->desc->dma_dir == DMA_MEM_TO_DEV)
+ moxart_dma_set_params(ch, sg->addr, d->dev_addr);
+ else if (ch->desc->dma_dir == DMA_DEV_TO_MEM)
+ moxart_dma_set_params(ch, d->dev_addr, sg->addr);
+
+ moxart_set_transfer_params(ch, sg->len);
+
+ moxart_start_dma(ch);
+}
+
+static void moxart_dma_start_desc(struct dma_chan *chan)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ struct virt_dma_desc *vd;
+
+ vd = vchan_next_desc(&ch->vc);
+
+ if (!vd) {
+ ch->desc = NULL;
+ return;
+ }
+
+ list_del(&vd->node);
+
+ ch->desc = to_moxart_dma_desc(&vd->tx);
+ ch->sgidx = 0;
+
+ moxart_dma_start_sg(ch, 0);
+}
+
+static void moxart_issue_pending(struct dma_chan *chan)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ch->vc.lock, flags);
+ if (vchan_issue_pending(&ch->vc) && !ch->desc)
+ moxart_dma_start_desc(chan);
+ spin_unlock_irqrestore(&ch->vc.lock, flags);
+}
+
+static size_t moxart_dma_desc_size(struct moxart_desc *d,
+ unsigned int completed_sgs)
+{
+ unsigned int i;
+ size_t size;
+
+ for (size = i = completed_sgs; i < d->sglen; i++)
+ size += d->sg[i].len;
+
+ return size;
+}
+
+static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch)
+{
+ size_t size;
+ unsigned int completed_cycles, cycles;
+
+ size = moxart_dma_desc_size(ch->desc, ch->sgidx);
+ cycles = readl(ch->base + REG_OFF_CYCLES);
+ completed_cycles = (ch->desc->dma_cycles - cycles);
+ size -= completed_cycles << es_bytes[ch->desc->es];
+
+ dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size);
+
+ return size;
+}
+
+static enum dma_status moxart_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct moxart_chan *ch = to_moxart_dma_chan(chan);
+ struct virt_dma_desc *vd;
+ struct moxart_desc *d;
+ enum dma_status ret;
+ unsigned long flags;
+
+ /*
+ * dma_cookie_status() assigns initial residue value.
+ */
+ ret = dma_cookie_status(chan, cookie, txstate);
+
+ spin_lock_irqsave(&ch->vc.lock, flags);
+ vd = vchan_find_desc(&ch->vc, cookie);
+ if (vd) {
+ d = to_moxart_dma_desc(&vd->tx);
+ txstate->residue = moxart_dma_desc_size(d, 0);
+ } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) {
+ txstate->residue = moxart_dma_desc_size_in_flight(ch);
+ }
+ spin_unlock_irqrestore(&ch->vc.lock, flags);
+
+ if (ch->error)
+ return DMA_ERROR;
+
+ return ret;
+}
+
+static void moxart_dma_init(struct dma_device *dma, struct device *dev)
+{
+ dma->device_prep_slave_sg = moxart_prep_slave_sg;
+ dma->device_alloc_chan_resources = moxart_alloc_chan_resources;
+ dma->device_free_chan_resources = moxart_free_chan_resources;
+ dma->device_issue_pending = moxart_issue_pending;
+ dma->device_tx_status = moxart_tx_status;
+ dma->device_config = moxart_slave_config;
+ dma->device_terminate_all = moxart_terminate_all;
+ dma->dev = dev;
+
+ INIT_LIST_HEAD(&dma->channels);
+}
+
+static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
+{
+ struct moxart_dmadev *mc = devid;
+ struct moxart_chan *ch = &mc->slave_chans[0];
+ unsigned int i;
+ unsigned long flags;
+ u32 ctrl;
+
+ dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__);
+
+ for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
+ if (!ch->allocated)
+ continue;
+
+ ctrl = readl(ch->base + REG_OFF_CTRL);
+
+ dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n",
+ __func__, ch, ch->base, ctrl);
+
+ if (ctrl & APB_DMA_FIN_INT_STS) {
+ ctrl &= ~APB_DMA_FIN_INT_STS;
+ if (ch->desc) {
+ spin_lock_irqsave(&ch->vc.lock, flags);
+ if (++ch->sgidx < ch->desc->sglen) {
+ moxart_dma_start_sg(ch, ch->sgidx);
+ } else {
+ vchan_cookie_complete(&ch->desc->vd);
+ moxart_dma_start_desc(&ch->vc.chan);
+ }
+ spin_unlock_irqrestore(&ch->vc.lock, flags);
+ }
+ }
+
+ if (ctrl & APB_DMA_ERR_INT_STS) {
+ ctrl &= ~APB_DMA_ERR_INT_STS;
+ ch->error = 1;
+ }
+
+ writel(ctrl, ch->base + REG_OFF_CTRL);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int moxart_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct resource *res;
+ static void __iomem *dma_base_addr;
+ int ret, i;
+ unsigned int irq;
+ struct moxart_chan *ch;
+ struct moxart_dmadev *mdc;
+
+ mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL);
+ if (!mdc) {
+ dev_err(dev, "can't allocate DMA container\n");
+ return -ENOMEM;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq == NO_IRQ) {
+ dev_err(dev, "no IRQ resource\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dma_base_addr = devm_ioremap_resource(dev, res);
+ if (IS_ERR(dma_base_addr))
+ return PTR_ERR(dma_base_addr);
+
+ dma_cap_zero(mdc->dma_slave.cap_mask);
+ dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask);
+ dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask);
+
+ moxart_dma_init(&mdc->dma_slave, dev);
+
+ ch = &mdc->slave_chans[0];
+ for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) {
+ ch->ch_num = i;
+ ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE;
+ ch->allocated = 0;
+
+ ch->vc.desc_free = moxart_dma_desc_free;
+ vchan_init(&ch->vc, &mdc->dma_slave);
+
+ dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n",
+ __func__, i, ch->ch_num, ch->base);
+ }
+
+ platform_set_drvdata(pdev, mdc);
+
+ ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0,
+ "moxart-dma-engine", mdc);
+ if (ret) {
+ dev_err(dev, "devm_request_irq failed\n");
+ return ret;
+ }
+
+ ret = dma_async_device_register(&mdc->dma_slave);
+ if (ret) {
+ dev_err(dev, "dma_async_device_register failed\n");
+ return ret;
+ }
+
+ ret = of_dma_controller_register(node, moxart_of_xlate, mdc);
+ if (ret) {
+ dev_err(dev, "of_dma_controller_register failed\n");
+ dma_async_device_unregister(&mdc->dma_slave);
+ return ret;
+ }
+
+ dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq);
+
+ return 0;
+}
+
+static int moxart_remove(struct platform_device *pdev)
+{
+ struct moxart_dmadev *m = platform_get_drvdata(pdev);
+
+ dma_async_device_unregister(&m->dma_slave);
+
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
+
+ return 0;
+}
+
+static const struct of_device_id moxart_dma_match[] = {
+ { .compatible = "moxa,moxart-dma" },
+ { }
+};
+
+static struct platform_driver moxart_driver = {
+ .probe = moxart_probe,
+ .remove = moxart_remove,
+ .driver = {
+ .name = "moxart-dma-engine",
+ .of_match_table = moxart_dma_match,
+ },
+};
+
+static int moxart_init(void)
+{
+ return platform_driver_register(&moxart_driver);
+}
+subsys_initcall(moxart_init);
+
+static void __exit moxart_exit(void)
+{
+ platform_driver_unregister(&moxart_driver);
+}
+module_exit(moxart_exit);
+
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
+MODULE_DESCRIPTION("MOXART DMA engine driver");
+MODULE_LICENSE("GPL v2");