new file mode 100644
@@ -0,0 +1,21 @@
+MOXA ART DMA Controller
+
+See dma.txt first
+
+Required properties:
+
+- compatible : Must be "moxa,moxart-dma"
+- reg : Should contain registers location and length
+- interrupts : Should contain the interrupt number
+- #dma-cells : Should be 2
+ cell index 0: channel number between 0-3
+ cell index 1: line request number
+
+Example:
+
+ dma: dma@90500000 {
+ compatible = "moxa,moxart-dma";
+ reg = <0x90500000 0x1000>;
+ interrupts = <24 0>;
+ #dma-cells = <1>;
+ };
@@ -300,6 +300,13 @@ config DMA_JZ4740
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
+config MOXART_DMA
+ tristate "MOXART DMA support"
+ depends on ARCH_MOXART
+ select DMA_ENGINE
+ help
+ Enable support for the MOXA ART SoC DMA controller.
+
config DMA_ENGINE
bool
@@ -39,3 +39,4 @@ obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
obj-$(CONFIG_DMA_OMAP) += omap-dma.o
obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
+obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
new file mode 100644
@@ -0,0 +1,610 @@
+/*
+ * 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/irq.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_dma.h>
+
+#include <asm/cacheflush.h>
+
+#include "dmaengine.h"
+
+#define APB_DMA_MAX_CHANNEL 4
+
+#define APB_DMA_ENABLE 0x1
+#define APB_DMA_FIN_INT_STS 0x2
+#define APB_DMA_FIN_INT_EN 0x4
+#define APB_DMA_BURST_MODE 0x8
+#define APB_DMA_ERR_INT_STS 0x10
+#define APB_DMA_ERR_INT_EN 0x20
+
+/*
+ * unset to select APB source
+ * set to select AHB source
+ */
+#define APB_DMA_SOURCE_SELECT 0x40
+
+/*
+ * unset to select APB destination
+ * set to select AHB destination
+ */
+#define APB_DMA_DEST_SELECT 0x80
+
+#define APB_DMA_SOURCE 0x100
+#define APB_DMA_SOURCE_MASK 0x700
+/*
+ * 000: no increment
+ * 001: +1 (busrt=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 0x1000
+#define APB_DMA_DEST_MASK 0x7000
+/*
+ * 000: no increment
+ * 001: +1 (busrt=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_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 of 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 == 5
+ *
+ * 0: no request / grant signal
+ * 1-15: request / grant signal
+ */
+#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
+
+/*
+ * request signal select of source
+ * 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 == 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
+
+struct moxart_dma_reg {
+ u32 source_addr;
+ u32 dest_addr;
+#define APB_DMA_CYCLES_MASK 0x00ffffff
+ u32 cycles; /* depend on burst mode */
+ u32 ctrl;
+};
+
+struct moxart_dma_chan {
+ struct dma_chan chan;
+ int ch_num;
+ bool allocated;
+ int error_flag;
+ struct moxart_dma_reg *reg;
+ void (*callback)(void *param);
+ void *callback_param;
+ struct completion dma_complete;
+ struct dma_slave_config cfg;
+ struct dma_async_tx_descriptor tx_desc;
+ unsigned int line;
+};
+
+struct moxart_dma_container {
+ int ctlr;
+ struct dma_device dma_slave;
+ struct moxart_dma_chan slave_chans[APB_DMA_MAX_CHANNEL];
+ spinlock_t dma_lock;
+};
+
+static struct device *chan2dev(struct dma_chan *chan)
+{
+ return &chan->dev->device;
+}
+
+static inline struct moxart_dma_container
+*to_dma_container(struct dma_device *d)
+{
+ return container_of(d, struct moxart_dma_container, dma_slave);
+}
+
+static inline struct moxart_dma_chan *to_moxart_dma_chan(struct dma_chan *c)
+{
+ return container_of(c, struct moxart_dma_chan, chan);
+}
+
+static int moxart_terminate_all(struct dma_chan *chan)
+{
+ struct moxart_dma_chan *ch = to_moxart_dma_chan(chan);
+ struct moxart_dma_container *c = to_dma_container(ch->chan.device);
+ u32 ctrl;
+ unsigned long flags;
+
+ dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch);
+
+ spin_lock_irqsave(&c->dma_lock, flags);
+
+ ctrl = readl(&ch->reg->ctrl);
+ ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
+ writel(ctrl, &ch->reg->ctrl);
+
+ spin_unlock_irqrestore(&c->dma_lock, flags);
+
+ return 0;
+}
+
+static int moxart_slave_config(struct dma_chan *chan,
+ struct dma_slave_config *cfg)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ struct moxart_dma_container *mc = to_dma_container(mchan->chan.device);
+ u32 ctrl;
+ unsigned long flags;
+
+ spin_lock_irqsave(&mc->dma_lock, flags);
+
+ memcpy(&mchan->cfg, cfg, sizeof(mchan->cfg));
+
+ ctrl = readl(&mchan->reg->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 (mchan->cfg.src_addr_width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ ctrl |= APB_DMA_DATA_WIDTH_1;
+ if (mchan->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 (mchan->cfg.direction != DMA_MEM_TO_DEV)
+ ctrl |= APB_DMA_DEST_INC_2_8;
+ else
+ ctrl |= APB_DMA_SOURCE_INC_2_8;
+ break;
+ default:
+ ctrl &= ~APB_DMA_DATA_WIDTH;
+ if (mchan->cfg.direction != DMA_MEM_TO_DEV)
+ ctrl |= APB_DMA_DEST_INC_4_16;
+ else
+ ctrl |= APB_DMA_SOURCE_INC_4_16;
+ break;
+ }
+
+ if (mchan->cfg.direction == DMA_MEM_TO_DEV) {
+ ctrl &= ~APB_DMA_DEST_SELECT;
+ ctrl |= APB_DMA_SOURCE_SELECT;
+ ctrl |= (mchan->line << 16 &
+ APB_DMA_DEST_REQ_NO_MASK);
+ } else {
+ ctrl |= APB_DMA_DEST_SELECT;
+ ctrl &= ~APB_DMA_SOURCE_SELECT;
+ ctrl |= (mchan->line << 24 &
+ APB_DMA_SOURCE_REQ_NO_MASK);
+ }
+
+ writel(ctrl, &mchan->reg->ctrl);
+
+ spin_unlock_irqrestore(&mc->dma_lock, flags);
+
+ return 0;
+}
+
+static int moxart_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+ struct dma_slave_config *config;
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ moxart_terminate_all(chan);
+ break;
+ case DMA_SLAVE_CONFIG:
+ config = (struct dma_slave_config *)arg;
+ ret = moxart_slave_config(chan, config);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ return ret;
+}
+
+static dma_cookie_t moxart_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(tx->chan);
+ struct moxart_dma_container *mc = to_dma_container(mchan->chan.device);
+ dma_cookie_t cookie;
+ u32 ctrl;
+ unsigned long flags;
+
+ mchan->callback = tx->callback;
+ mchan->callback_param = tx->callback_param;
+ mchan->error_flag = 0;
+
+ dev_dbg(chan2dev(tx->chan), "%s: mchan=%p mchan->ch_num=%d mchan->reg=%p\n",
+ __func__, mchan, mchan->ch_num, mchan->reg);
+
+ spin_lock_irqsave(&mc->dma_lock, flags);
+
+ cookie = dma_cookie_assign(tx);
+
+ ctrl = readl(&mchan->reg->ctrl);
+ ctrl |= (APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
+ writel(ctrl, &mchan->reg->ctrl);
+
+ spin_unlock_irqrestore(&mc->dma_lock, flags);
+
+ return cookie;
+}
+
+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 direction,
+ unsigned long tx_flags, void *context)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ struct moxart_dma_container *mc = to_dma_container(mchan->chan.device);
+ unsigned long flags;
+ unsigned int size, adr_width;
+
+ spin_lock_irqsave(&mc->dma_lock, flags);
+
+ if (direction == DMA_MEM_TO_DEV) {
+ writel(virt_to_phys((void *)sg_dma_address(&sgl[0])),
+ &mchan->reg->source_addr);
+ writel(mchan->cfg.dst_addr, &mchan->reg->dest_addr);
+ adr_width = mchan->cfg.src_addr_width;
+ } else {
+ writel(mchan->cfg.src_addr, &mchan->reg->source_addr);
+ writel(virt_to_phys((void *)sg_dma_address(&sgl[0])),
+ &mchan->reg->dest_addr);
+ adr_width = mchan->cfg.dst_addr_width;
+ }
+
+ size = sgl->length >> adr_width;
+
+ /*
+ * size is 4 on 64 bytes copied, i.e. once cycle copies 16 bytes
+ * ( when data_width == APB_DMAB_DATA_WIDTH_4 )
+ */
+ writel(size, &mchan->reg->cycles);
+
+ dev_dbg(chan2dev(chan), "%s: set %d DMA cycles (sgl->length=%d adr_width=%d)\n",
+ __func__, size, sgl->length, adr_width);
+
+ dma_async_tx_descriptor_init(&mchan->tx_desc, chan);
+ mchan->tx_desc.tx_submit = moxart_tx_submit;
+
+ spin_unlock_irqrestore(&mc->dma_lock, flags);
+
+ return &mchan->tx_desc;
+}
+
+bool moxart_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ struct moxart_dma_container *mc = to_dma_container(mchan->chan.device);
+
+ if (chan->device->dev == mc->dma_slave.dev) {
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ unsigned int ch_req = *(unsigned int *)param;
+ dev_dbg(chan2dev(chan), "%s: mchan=%p ch_req=%d mchan->ch_num=%d\n",
+ __func__, mchan, ch_req, mchan->ch_num);
+ return ch_req == mchan->ch_num;
+ } else {
+ dev_dbg(chan2dev(chan), "%s: device not registered to this DMA engine\n",
+ __func__);
+ return false;
+ }
+}
+
+static struct of_dma_filter_info moxart_dma_info = {
+ .filter_fn = moxart_dma_filter_fn,
+};
+
+static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct dma_chan *chan;
+ struct of_dma_filter_info *info = ofdma->of_dma_data;
+
+ if (!info || !info->filter_fn)
+ return NULL;
+
+ if (dma_spec->args_count != 2)
+ return NULL;
+
+ chan = dma_request_channel(info->dma_cap, info->filter_fn,
+ &dma_spec->args[0]);
+ if (chan)
+ to_moxart_dma_chan(chan)->line = dma_spec->args[1];
+
+ return chan;
+}
+
+static int moxart_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ int i;
+ bool found = false;
+
+ for (i = 0; i < APB_DMA_MAX_CHANNEL; i++) {
+ if (i == mchan->ch_num
+ && !mchan->allocated) {
+ dev_dbg(chan2dev(chan), "%s: allocating channel #%d\n",
+ __func__, mchan->ch_num);
+ mchan->allocated = true;
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return -ENODEV;
+
+ return 0;
+}
+
+static void moxart_free_chan_resources(struct dma_chan *chan)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+
+ mchan->allocated = false;
+
+ dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n",
+ __func__, mchan->ch_num);
+}
+
+static void moxart_issue_pending(struct dma_chan *chan)
+{
+ struct moxart_dma_chan *mchan = to_moxart_dma_chan(chan);
+ struct moxart_dma_container *mc = to_dma_container(mchan->chan.device);
+ u32 ctrl;
+ unsigned long flags;
+
+ dev_dbg(chan2dev(chan), "%s: mchan=%p\n", __func__, mchan);
+
+ spin_lock_irqsave(&mc->dma_lock, flags);
+
+ ctrl = readl(&mchan->reg->ctrl);
+ ctrl |= APB_DMA_ENABLE;
+ writel(ctrl, &mchan->reg->ctrl);
+
+ spin_unlock_irqrestore(&mc->dma_lock, flags);
+}
+
+static enum dma_status moxart_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ enum dma_status ret;
+
+ ret = dma_cookie_status(chan, cookie, txstate);
+ if (ret == DMA_SUCCESS || !txstate)
+ return ret;
+
+ 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_control = moxart_control;
+ dma->dev = dev;
+
+ INIT_LIST_HEAD(&dma->channels);
+}
+
+static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
+{
+ struct moxart_dma_container *mc = to_dma_container(devid);
+ struct moxart_dma_chan *mchan = &mc->slave_chans[0];
+ unsigned int i;
+ u32 ctrl;
+
+ pr_debug("%s\n", __func__);
+
+ for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, mchan++) {
+ if (mchan->allocated) {
+ ctrl = readl(&mchan->reg->ctrl);
+ if (ctrl & APB_DMA_FIN_INT_STS) {
+ ctrl &= ~APB_DMA_FIN_INT_STS;
+ dma_cookie_complete(&mchan->tx_desc);
+ }
+ if (ctrl & APB_DMA_ERR_INT_STS) {
+ ctrl &= ~APB_DMA_ERR_INT_STS;
+ mchan->error_flag = 1;
+ }
+ if (mchan->callback) {
+ pr_debug("%s: call callback for mchan=%p\n",
+ __func__, mchan);
+ mchan->callback(mchan->callback_param);
+ }
+ mchan->error_flag = 0;
+ writel(ctrl, &mchan->reg->ctrl);
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction moxart_dma_irq = {
+ .name = "moxart-dma-engine",
+ .flags = IRQF_DISABLED,
+ .handler = moxart_dma_interrupt,
+};
+
+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_dma_chan *mchan;
+ struct moxart_dma_container *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);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dma_base_addr = devm_ioremap_resource(dev, res);
+ if (IS_ERR(dma_base_addr)) {
+ dev_err(dev, "devm_ioremap_resource failed\n");
+ return PTR_ERR(dma_base_addr);
+ }
+
+ mdc->ctlr = pdev->id;
+ spin_lock_init(&mdc->dma_lock);
+
+ dma_cap_zero(mdc->dma_slave.cap_mask);
+ dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask);
+
+ moxart_dma_init(&mdc->dma_slave, dev);
+
+ mchan = &mdc->slave_chans[0];
+ for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, mchan++) {
+ mchan->ch_num = i;
+ mchan->reg = (struct moxart_dma_reg *)(dma_base_addr + 0x80
+ + i * sizeof(struct moxart_dma_reg));
+ mchan->callback = NULL;
+ mchan->allocated = 0;
+ mchan->callback_param = NULL;
+
+ dma_cookie_init(&mchan->chan);
+ mchan->chan.device = &mdc->dma_slave;
+ list_add_tail(&mchan->chan.device_node,
+ &mdc->dma_slave.channels);
+
+ dev_dbg(dev, "%s: mchans[%d]: mchan->ch_num=%d mchan->reg=%p\n",
+ __func__, i, mchan->ch_num, mchan->reg);
+ }
+
+ ret = dma_async_device_register(&mdc->dma_slave);
+ platform_set_drvdata(pdev, mdc);
+
+ of_dma_controller_register(node, moxart_of_xlate, &moxart_dma_info);
+
+ moxart_dma_irq.dev_id = &mdc->dma_slave;
+ setup_irq(irq, &moxart_dma_irq);
+
+ dev_dbg(dev, "%s: IRQ=%d\n", __func__, irq);
+
+ return ret;
+}
+
+static int moxart_remove(struct platform_device *pdev)
+{
+ struct moxart_dma_container *m = dev_get_drvdata(&pdev->dev);
+ dma_async_device_unregister(&m->dma_slave);
+ 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",
+ .owner = THIS_MODULE,
+ .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");
Add dmaengine driver for MOXA ART SoCs. Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com> --- Notes: Preemptively submitting a new version that has the previously mentioned two cell xlate. Changes since v5: 1. add line request number and use two cell xlate device tree bindings document: 2. update description, describe the two cells of #dma-cells Applies to next-20130802 .../devicetree/bindings/dma/moxa,moxart-dma.txt | 21 + drivers/dma/Kconfig | 7 + drivers/dma/Makefile | 1 + drivers/dma/moxart-dma.c | 610 +++++++++++++++++++++ 4 files changed, 639 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/moxa,moxart-dma.txt create mode 100644 drivers/dma/moxart-dma.c