[PATCH v2 3/3] dmaengine: sf-pdma: add platform DMA support for HiFive Unleashed A00
From: Green Wan
Date: Thu Sep 19 2019 - 03:30:24 EST
Link: https://www.kernel.org/doc/html/v4.17/driver-api/dmaengine/
Link: https://static.dev.sifive.com/FU540-C000-v1.0.pdf
Add PDMA driver, sf-pdma, to enable DMA engine on HiFive Unleashed
Rev A00 board.
- Implement dmaengine APIs, support MEM_TO_MEM async copy.
- Tested by DMA Test client
- Supports 4 channels DMA, each channel has 1 done and 1 err
interrupt connected to platform-level interrupt controller (PLIC).
- Depends on DMA_ENGINE and DMA_VIRTUAL_CHANNELS
Follow the DMAengine controller doc,
"./Documentation/driver-api/dmaengine/provider.rst" to implement DMA
engine. And use the dma test client in doc,
"./Documentation/driver-api/dmaengine/dmatest.rst", to test.
Each DMA channel has separate HW regs and support done and error ISRs.
4 channels share 1 done and 1 err ISRs. There's no expander/arbitrator
in DMA HW.
------ ------
| |--< done 23 >--|ch 0|
| |--< err 24 >--| | (dma0chan0)
| | ------
| | ------
| |--< done 25 >--|ch 1|
| |--< err 26 >--| | (dma0chan1)
|PLIC| ------
| | ------
| |--< done 27 >--|ch 2|
| |--< err 28 >--| | (dma0chan2)
| | ------
| | ------
| |--< done 29 >--|ch 3|
| |--< err 30 >--| | (dma0chan3)
------ ------
Signed-off-by: Green Wan <green.wan@xxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/dma/Kconfig | 2 +
drivers/dma/Makefile | 1 +
drivers/dma/sf-pdma/Kconfig | 6 +
drivers/dma/sf-pdma/Makefile | 1 +
drivers/dma/sf-pdma/sf-pdma.c | 623 ++++++++++++++++++++++++++++++++++
drivers/dma/sf-pdma/sf-pdma.h | 124 +++++++
7 files changed, 758 insertions(+)
create mode 100644 drivers/dma/sf-pdma/Kconfig
create mode 100644 drivers/dma/sf-pdma/Makefile
create mode 100644 drivers/dma/sf-pdma/sf-pdma.c
create mode 100644 drivers/dma/sf-pdma/sf-pdma.h
diff --git a/MAINTAINERS b/MAINTAINERS
index d0caa09a479e..c5f0662c9106 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14594,6 +14594,7 @@ F: drivers/media/mmc/siano/
SIFIVE PDMA DRIVER
M: Green Wan <green.wan@xxxxxxxxxx>
S: Maintained
+F: drivers/dma/sf-pdma/
F: Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
SIFIVE DRIVERS
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 413efef5fbb6..f05a928f5a3d 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -667,6 +667,8 @@ source "drivers/dma/qcom/Kconfig"
source "drivers/dma/dw/Kconfig"
+source "drivers/dma/sf-pdma/Kconfig"
+
source "drivers/dma/dw-edma/Kconfig"
source "drivers/dma/hsu/Kconfig"
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 5bddf6f8790f..77a552d970ae 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_DMA_SUN4I) += sun4i-dma.o
obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
obj-$(CONFIG_DW_AXI_DMAC) += dw-axi-dmac/
obj-$(CONFIG_DW_DMAC_CORE) += dw/
+obj-$(CONFIG_SF_PDMA) += sf-pdma/
obj-$(CONFIG_DW_EDMA) += dw-edma/
obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o
obj-$(CONFIG_FSL_DMA) += fsldma.o
diff --git a/drivers/dma/sf-pdma/Kconfig b/drivers/dma/sf-pdma/Kconfig
new file mode 100644
index 000000000000..0e01a5728a79
--- /dev/null
+++ b/drivers/dma/sf-pdma/Kconfig
@@ -0,0 +1,6 @@
+config SF_PDMA
+ bool "Sifive PDMA controller driver"
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Support the SiFive PDMA controller.
diff --git a/drivers/dma/sf-pdma/Makefile b/drivers/dma/sf-pdma/Makefile
new file mode 100644
index 000000000000..764552ab8d0a
--- /dev/null
+++ b/drivers/dma/sf-pdma/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SF_PDMA) += sf-pdma.o
diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c
new file mode 100644
index 000000000000..0ebf8a819811
--- /dev/null
+++ b/drivers/dma/sf-pdma/sf-pdma.c
@@ -0,0 +1,623 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/**
+ * SiFive FU540 Platform DMA driver
+ * Copyright (C) 2019 SiFive
+ *
+ * Based partially on:
+ * - drivers/dma/fsl-edma.c
+ * - drivers/dma/dw-edma/
+ * - drivers/dma/pxa-dma.c
+ *
+ * See the following sources for further documentation:
+ * - Chapter 12 "Platform DMA Engine (PDMA)" of
+ * SiFive FU540-C000 v1.0
+ * https://static.dev.sifive.com/FU540-C000-v1.0.pdf
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/pm_runtime.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_dma.h>
+#include <linux/time64.h>
+
+#include "sf-pdma.h"
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+#define SIFIVE_PDMA_NAME "sf-pdma"
+
+#ifndef readq
+static inline unsigned long long readq(void __iomem *addr)
+{
+ return readl(addr) | (((unsigned long long)readl(addr + 4)) << 32LL);
+}
+#endif
+
+#ifndef writeq
+static inline void writeq(unsigned long long v, void __iomem *addr)
+{
+ writel(v & 0xffffffff, addr);
+ writel(v >> 32, addr + 4);
+}
+#endif
+
+static inline struct sf_pdma_chan *to_sf_pdma_chan(struct dma_chan *dchan)
+{
+ return container_of(dchan, struct sf_pdma_chan, vchan.chan);
+}
+
+static inline struct sf_pdma_desc *to_sf_pdma_desc(struct virt_dma_desc *vd)
+{
+ return container_of(vd, struct sf_pdma_desc, vdesc);
+}
+
+static struct sf_pdma_desc *sf_pdma_alloc_desc(struct sf_pdma_chan *chan)
+{
+ struct sf_pdma_desc *desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+
+ if (chan->desc && !chan->desc->in_use) {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ return chan->desc;
+ }
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
+
+ if (!desc)
+ return NULL;
+
+ desc->chan = chan;
+
+ return desc;
+}
+
+static void sf_pdma_fill_desc(struct sf_pdma_chan *chan,
+ u64 dst,
+ u64 src,
+ u64 size)
+{
+ struct pdma_regs *regs = &chan->regs;
+
+ writel(PDMA_FULL_SPEED, regs->xfer_type);
+ writeq(size, regs->xfer_size);
+ writeq(dst, regs->dst_addr);
+ writeq(src, regs->src_addr);
+}
+
+void sf_pdma_disclaim_chan(struct sf_pdma_chan *chan)
+{
+ struct pdma_regs *regs = &chan->regs;
+
+ writel(PDMA_CLEAR_CTRL, regs->ctrl);
+}
+
+struct dma_async_tx_descriptor *
+ sf_pdma_prep_dma_memcpy(struct dma_chan *dchan,
+ dma_addr_t dest,
+ dma_addr_t src,
+ size_t len,
+ unsigned long flags)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ struct sf_pdma_desc *desc;
+
+ if (!chan || !len || !dest || !src) {
+ pr_debug("%s: Please check dma len, dest, src!\n", __func__);
+ return NULL;
+ }
+
+ desc = sf_pdma_alloc_desc(chan);
+ if (!desc)
+ return NULL;
+
+ desc->in_use = true;
+ desc->dirn = DMA_MEM_TO_MEM;
+ desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->desc = desc;
+ sf_pdma_fill_desc(desc->chan, dest, src, len);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ return desc->async_tx;
+}
+
+static void sf_pdma_unprep_slave_dma(struct sf_pdma_chan *chan)
+{
+ if (chan->dma_dir != DMA_NONE)
+ dma_unmap_resource(chan->vchan.chan.device->dev,
+ chan->dma_dev_addr,
+ chan->dma_dev_size,
+ chan->dma_dir, 0);
+ chan->dma_dir = DMA_NONE;
+}
+
+static int sf_pdma_slave_config(struct dma_chan *dchan,
+ struct dma_slave_config *cfg)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+
+ memcpy(&chan->cfg, cfg, sizeof(*cfg));
+ sf_pdma_unprep_slave_dma(chan);
+
+ return 0;
+}
+
+static int sf_pdma_alloc_chan_resources(struct dma_chan *dchan)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ struct pdma_regs *regs = &chan->regs;
+
+ dma_cookie_init(dchan);
+ writel(PDMA_CLAIM_MASK, regs->ctrl);
+
+ return 0;
+}
+
+static void sf_pdma_disable_request(struct sf_pdma_chan *chan)
+{
+ struct pdma_regs *regs = &chan->regs;
+
+ writel(readl(regs->ctrl) & ~PDMA_RUN_MASK, regs->ctrl);
+}
+
+static void sf_pdma_free_chan_resources(struct dma_chan *dchan)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ sf_pdma_disable_request(chan);
+ kfree(chan->desc);
+ chan->desc = NULL;
+ vchan_get_all_descriptors(&chan->vchan, &head);
+ sf_pdma_unprep_slave_dma(chan);
+ vchan_dma_desc_free_list(&chan->vchan, &head);
+ sf_pdma_disclaim_chan(chan);
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static size_t sf_pdma_desc_residue(struct sf_pdma_chan *chan,
+ dma_cookie_t cookie)
+{
+ struct virt_dma_desc *vd = NULL;
+ struct sf_pdma_desc *desc;
+ struct pdma_regs *regs = &chan->regs;
+ unsigned long flags;
+ u64 residue;
+
+ residue = readq(regs->residue);
+
+ chan->status = residue ? DMA_IN_PROGRESS : DMA_COMPLETE;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ vd = vchan_find_desc(&chan->vchan, cookie);
+ if (!vd)
+ goto out;
+
+ desc = to_sf_pdma_desc(vd);
+
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+ if (desc && chan->status == DMA_COMPLETE)
+ vchan_tx_desc_free(desc->async_tx);
+
+ return residue;
+
+out:
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+ return residue;
+}
+
+static enum dma_status
+sf_pdma_tx_status(struct dma_chan *dchan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ enum dma_status status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (chan->xfer_err) {
+ chan->status = DMA_ERROR;
+ spin_unlock_irqrestore(&chan->lock, flags);
+ return chan->status;
+ }
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ status = dma_cookie_status(dchan, cookie, txstate);
+
+ if (status == DMA_COMPLETE)
+ return status;
+
+ if (!txstate)
+ return chan->status;
+
+ txstate->residue = sf_pdma_desc_residue(chan, cookie);
+
+ return chan->status;
+}
+
+static int sf_pdma_terminate_all(struct dma_chan *dchan)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+ sf_pdma_disable_request(chan);
+ kfree(chan->desc);
+ chan->desc = NULL;
+ chan->xfer_err = false;
+ vchan_get_all_descriptors(&chan->vchan, &head);
+ vchan_dma_desc_free_list(&chan->vchan, &head);
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+
+ return 0;
+}
+
+static void sf_pdma_enable_request(struct sf_pdma_chan *chan)
+{
+ struct pdma_regs *regs = &chan->regs;
+ u32 v;
+
+ v = PDMA_CLAIM_MASK |
+ PDMA_ENABLE_DONE_INT_MASK |
+ PDMA_ENABLE_ERR_INT_MASK |
+ PDMA_RUN_MASK;
+
+ writel(v, regs->ctrl);
+}
+
+static void sf_pdma_xfer_desc(struct sf_pdma_chan *chan)
+{
+ struct virt_dma_desc *vdesc;
+
+ vdesc = vchan_next_desc(&chan->vchan);
+ if (!vdesc)
+ return;
+
+ chan->desc = to_sf_pdma_desc(vdesc);
+ chan->status = DMA_IN_PROGRESS;
+}
+
+static void sf_pdma_issue_pending(struct dma_chan *dchan)
+{
+ struct sf_pdma_chan *chan = to_sf_pdma_chan(dchan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->vchan.lock, flags);
+
+ if (chan->pm_state != RUNNING) {
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+ /* cannot submit due to suspend */
+ return;
+ }
+
+ if (vchan_issue_pending(&chan->vchan) && !chan->desc)
+ sf_pdma_xfer_desc(chan);
+
+ sf_pdma_enable_request(chan);
+ spin_unlock_irqrestore(&chan->vchan.lock, flags);
+}
+
+static void sf_pdma_free_desc(struct virt_dma_desc *vdesc)
+{
+ struct sf_pdma_desc *desc;
+
+ desc = to_sf_pdma_desc(vdesc);
+ desc->in_use = false;
+}
+
+static void sf_pdma_donebh_tasklet(unsigned long arg)
+{
+ struct sf_pdma_chan *chan = (struct sf_pdma_chan *)arg;
+ struct sf_pdma_desc *desc = chan->desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (chan->xfer_err) {
+ chan->retries = MAX_RETRY;
+ chan->status = DMA_COMPLETE;
+ chan->xfer_err = false;
+ }
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ dmaengine_desc_get_callback_invoke(desc->async_tx, NULL);
+}
+
+static void sf_pdma_errbh_tasklet(unsigned long arg)
+{
+ struct sf_pdma_chan *chan = (struct sf_pdma_chan *)arg;
+ struct sf_pdma_desc *desc = chan->desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ if (chan->retries <= 0) {
+ /* fail to recover, tx_status() is in DMA_ERROR */
+ spin_unlock_irqrestore(&chan->lock, flags);
+ dmaengine_desc_get_callback_invoke(desc->async_tx, NULL);
+ } else {
+ /* retry */
+ chan->retries--;
+ chan->xfer_err = true;
+ chan->status = DMA_ERROR;
+
+ sf_pdma_enable_request(chan);
+ spin_unlock_irqrestore(&chan->lock, flags);
+ }
+}
+
+static irqreturn_t sf_pdma_done_isr(int irq, void *dev_id)
+{
+ struct sf_pdma_chan *chan = dev_id;
+ struct pdma_regs *regs = &chan->regs;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ writel((readl(regs->ctrl)) & ~PDMA_DONE_STATUS_MASK, regs->ctrl);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ tasklet_hi_schedule(&chan->done_tasklet);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t sf_pdma_err_isr(int irq, void *dev_id)
+{
+ struct sf_pdma_chan *chan = dev_id;
+ struct pdma_regs *regs = &chan->regs;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ writel((readl(regs->ctrl)) & ~PDMA_ERR_STATUS_MASK, regs->ctrl);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ tasklet_schedule(&chan->err_tasklet);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * sf_pdma_irq_init() - Init PDMA IRQ Handlers
+ * @pdev: pointer of platform_device
+ * @pdma: pointer of PDMA engine. Caller should check NULL
+ *
+ * Initialize DONE and ERROR interrupt handler for 4 channels. Caller should
+ * make sure the pointer passed in are non-NULL. This function should be called
+ * only one time during the device probe.
+ *
+ * Context: Any context.
+ *
+ * Return:
+ * * 0 - OK to init all IRQ handlers
+ * * irq - Fail to retrieve from DT binding
+ * * -1 - Fail to call request_irq()
+ */
+static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
+{
+ int irq, r, i;
+ struct sf_pdma_chan *chan;
+
+ for (i = 0; i < pdma->n_chans; i++) {
+ chan = &pdma->chans[i];
+
+ irq = platform_get_irq(pdev, i * 2);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "Can't get pdma done irq.\n");
+ return irq;
+ }
+
+ r = request_irq(irq, sf_pdma_done_isr, 0,
+ dev_name(&pdev->dev), (void *)chan);
+ if (r) {
+ dev_err(&pdev->dev, "Fail to attach done ISR: %d\n", r);
+ return -1;
+ }
+
+ chan->txirq = irq;
+
+ irq = platform_get_irq(pdev, (i * 2) + 1);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "Can't get pdma err irq.\n");
+ return irq;
+ }
+
+ r = request_irq(irq, sf_pdma_err_isr, 0,
+ dev_name(&pdev->dev), (void *)chan);
+ if (r) {
+ dev_err(&pdev->dev, "Fail to attach err ISR: %d\n", r);
+ return -1;
+ }
+
+ chan->errirq = irq;
+ }
+
+ return 0;
+}
+
+/**
+ * sf_pdma_setup_chans() - Init settings of each channel
+ * @pdma: pointer of PDMA engine. Caller should check NULL
+ *
+ * Initialize all data structure and register base. Caller should make sure
+ * the pointer passed in are non-NULL. This function should be called only
+ * one time during the device probe.
+ *
+ * Context: Any context.
+ *
+ * Return: none
+ */
+#define SF_PDMA_REG_BASE(ch) (pdma->membase + (PDMA_CHAN_OFFSET * (ch)))
+static void sf_pdma_setup_chans(struct sf_pdma *pdma)
+{
+ int i;
+ struct sf_pdma_chan *chan;
+
+ INIT_LIST_HEAD(&pdma->dma_dev.channels);
+
+ for (i = 0; i < pdma->n_chans; i++) {
+ chan = &pdma->chans[i];
+
+ chan->regs.ctrl =
+ SF_PDMA_REG_BASE(i) + PDMA_CTRL;
+ chan->regs.xfer_type =
+ SF_PDMA_REG_BASE(i) + PDMA_XFER_TYPE;
+ chan->regs.xfer_size =
+ SF_PDMA_REG_BASE(i) + PDMA_XFER_SIZE;
+ chan->regs.dst_addr =
+ SF_PDMA_REG_BASE(i) + PDMA_DST_ADDR;
+ chan->regs.src_addr =
+ SF_PDMA_REG_BASE(i) + PDMA_SRC_ADDR;
+ chan->regs.act_type =
+ SF_PDMA_REG_BASE(i) + PDMA_ACT_TYPE;
+ chan->regs.residue =
+ SF_PDMA_REG_BASE(i) + PDMA_REMAINING_BYTE;
+ chan->regs.cur_dst_addr =
+ SF_PDMA_REG_BASE(i) + PDMA_CUR_DST_ADDR;
+ chan->regs.cur_src_addr =
+ SF_PDMA_REG_BASE(i) + PDMA_CUR_SRC_ADDR;
+
+ chan->pdma = pdma;
+ chan->pm_state = RUNNING;
+ chan->slave_id = i;
+ chan->xfer_err = false;
+ spin_lock_init(&chan->lock);
+
+ chan->vchan.desc_free = sf_pdma_free_desc;
+ vchan_init(&chan->vchan, &pdma->dma_dev);
+
+ writel(PDMA_CLEAR_CTRL, chan->regs.ctrl);
+
+ tasklet_init(&chan->done_tasklet,
+ sf_pdma_donebh_tasklet, (unsigned long)chan);
+ tasklet_init(&chan->err_tasklet,
+ sf_pdma_errbh_tasklet, (unsigned long)chan);
+ }
+}
+
+static int sf_pdma_probe(struct platform_device *pdev)
+{
+ struct sf_pdma *pdma;
+ struct sf_pdma_chan *chan;
+ struct resource *res;
+ int len, chans;
+ int ret;
+
+ chans = PDMA_NR_CH;
+ len = sizeof(*pdma) + sizeof(*chan) * chans;
+ pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+ if (!pdma)
+ return -ENOMEM;
+
+ pdma->n_chans = chans;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pdma->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pdma->membase))
+ goto ERR_MEMBASE;
+
+ ret = sf_pdma_irq_init(pdev, pdma);
+ if (ret)
+ goto ERR_INITIRQ;
+
+ sf_pdma_setup_chans(pdma);
+
+ pdma->dma_dev.dev = &pdev->dev;
+ dma_cap_set(DMA_MEMCPY, pdma->dma_dev.cap_mask);
+
+ ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+ if (ret)
+ pr_warn("*** Failed to set DMA mask. Fall back to default.\n");
+
+ /* Setup DMA APIs */
+ pdma->dma_dev.device_alloc_chan_resources =
+ sf_pdma_alloc_chan_resources;
+ pdma->dma_dev.device_free_chan_resources =
+ sf_pdma_free_chan_resources;
+ pdma->dma_dev.device_tx_status = sf_pdma_tx_status;
+ pdma->dma_dev.device_prep_dma_memcpy = sf_pdma_prep_dma_memcpy;
+ pdma->dma_dev.device_config = sf_pdma_slave_config;
+ pdma->dma_dev.device_terminate_all = sf_pdma_terminate_all;
+ pdma->dma_dev.device_issue_pending = sf_pdma_issue_pending;
+
+ platform_set_drvdata(pdev, pdma);
+
+ ret = dma_async_device_register(&pdma->dma_dev);
+ if (ret)
+ goto ERR_REG_DMADEVICE;
+
+ return 0;
+
+ERR_MEMBASE:
+ devm_kfree(&pdev->dev, pdma);
+ return PTR_ERR(pdma->membase);
+
+ERR_INITIRQ:
+ devm_kfree(&pdev->dev, pdma);
+ return ret;
+
+ERR_REG_DMADEVICE:
+ devm_kfree(&pdev->dev, pdma);
+ dev_err(&pdev->dev,
+ "Can't register SiFive Platform DMA. (%d)\n", ret);
+ return ret;
+}
+
+static int sf_pdma_remove(struct platform_device *pdev)
+{
+ struct sf_pdma *pdma = platform_get_drvdata(pdev);
+
+ dma_async_device_unregister(&pdma->dma_dev);
+
+ return 0;
+}
+
+static const struct of_device_id sf_pdma_of_match[] = {
+ { .compatible = "sifive,fu540-c000-pdma" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sifive_serial_of_match);
+
+static struct platform_driver sf_pdma_driver = {
+ .probe = sf_pdma_probe,
+ .remove = sf_pdma_remove,
+ .driver = {
+ .name = SIFIVE_PDMA_NAME,
+ .of_match_table = of_match_ptr(sf_pdma_of_match),
+ },
+};
+
+static int __init sf_pdma_init(void)
+{
+ return platform_driver_register(&sf_pdma_driver);
+}
+
+static void __exit sf_pdma_exit(void)
+{
+ platform_driver_unregister(&sf_pdma_driver);
+}
+
+/* do early init */
+subsys_initcall(sf_pdma_init);
+module_exit(sf_pdma_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SiFive Platform DMA driver");
+MODULE_AUTHOR("Green Wan <green.wan@xxxxxxxxxx>");
diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h
new file mode 100644
index 000000000000..d577d5af0bf4
--- /dev/null
+++ b/drivers/dma/sf-pdma/sf-pdma.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/**
+ * SiFive FU540 Platform DMA driver
+ * Copyright (C) 2019 SiFive
+ *
+ * Based partially on:
+ * - drivers/dma/fsl-edma.c
+ * - drivers/dma/dw-edma/
+ * - drivers/dma/pxa-dma.c
+ *
+ * See the following sources for further documentation:
+ * - Chapter 12 "Platform DMA Engine (PDMA)" of
+ * SiFive FU540-C000 v1.0
+ * https://static.dev.sifive.com/FU540-C000-v1.0.pdf
+ */
+#ifndef _SF_PDMA_H
+#define _SF_PDMA_H
+
+#include <linux/msi.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-direction.h>
+#include <linux/timer.h>
+#include <linux/time64.h>
+#include <linux/timekeeping.h>
+#include <linux/workqueue.h>
+
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+#define PDMA_NR_CH 4
+
+#if (PDMA_NR_CH != 4)
+#error "Please define PDMA_NR_CH to 4"
+#endif
+
+#define PDMA_BASE_ADDR 0x3000000
+#define PDMA_CHAN_OFFSET 0x1000
+
+/* Register Offset */
+#define PDMA_CTRL 0x000
+#define PDMA_XFER_TYPE 0x004
+#define PDMA_XFER_SIZE 0x008
+#define PDMA_DST_ADDR 0x010
+#define PDMA_SRC_ADDR 0x018
+#define PDMA_ACT_TYPE 0x104 /* Read-only */
+#define PDMA_REMAINING_BYTE 0x108 /* Read-only */
+#define PDMA_CUR_DST_ADDR 0x110 /* Read-only*/
+#define PDMA_CUR_SRC_ADDR 0x118 /* Read-only*/
+
+/* CTRL */
+#define PDMA_CLEAR_CTRL 0x0
+#define PDMA_CLAIM_MASK GENMASK(0, 0)
+#define PDMA_RUN_MASK GENMASK(1, 1)
+#define PDMA_ENABLE_DONE_INT_MASK GENMASK(14, 14)
+#define PDMA_ENABLE_ERR_INT_MASK GENMASK(15, 15)
+#define PDMA_DONE_STATUS_MASK GENMASK(30, 30)
+#define PDMA_ERR_STATUS_MASK GENMASK(31, 31)
+
+/* Transfer Type */
+#define PDMA_FULL_SPEED 0xFF000008
+
+/* Error Recovery */
+#define MAX_RETRY 1
+
+struct pdma_regs {
+ /* read-write regs */
+ void __iomem *ctrl; /* 4 bytes */
+
+ void __iomem *xfer_type; /* 4 bytes */
+ void __iomem *xfer_size; /* 8 bytes */
+ void __iomem *dst_addr; /* 8 bytes */
+ void __iomem *src_addr; /* 8 bytes */
+
+ /* read-only */
+ void __iomem *act_type; /* 4 bytes */
+ void __iomem *residue; /* 8 bytes */
+ void __iomem *cur_dst_addr; /* 8 bytes */
+ void __iomem *cur_src_addr; /* 8 bytes */
+};
+
+struct sf_pdma_desc {
+ struct virt_dma_desc vdesc;
+ struct sf_pdma_chan *chan;
+ bool in_use;
+ enum dma_transfer_direction dirn;
+ struct dma_async_tx_descriptor *async_tx;
+};
+
+enum sf_pdma_pm_state {
+ RUNNING = 0,
+ SUSPENDED,
+};
+
+struct sf_pdma_chan {
+ struct virt_dma_chan vchan;
+ enum dma_status status;
+ enum sf_pdma_pm_state pm_state;
+ u32 slave_id;
+ struct sf_pdma *pdma;
+ struct sf_pdma_desc *desc;
+ struct dma_slave_config cfg;
+ u32 attr;
+ dma_addr_t dma_dev_addr;
+ u32 dma_dev_size;
+ enum dma_data_direction dma_dir;
+ struct tasklet_struct done_tasklet;
+ struct tasklet_struct err_tasklet;
+ struct pdma_regs regs;
+ spinlock_t lock; /* protect chan data */
+ bool xfer_err;
+ int txirq;
+ int errirq;
+ int retries;
+};
+
+struct sf_pdma {
+ struct dma_device dma_dev;
+ void __iomem *membase;
+ void __iomem *mappedbase;
+ u32 n_chans;
+ struct sf_pdma_chan chans[PDMA_NR_CH];
+};
+
+#endif /* _SF_PDMA_H */
--
2.17.1