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Subject[PATCH V3] dmaengine: Loongson1: add Loongson1 dmaengine driver
Date
From: Kelvin Cheung <keguang.zhang@gmail.com>

This patch adds DMA Engine driver for Loongson1B.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>

---
V3:
Rename ls1x_dma_filter_fn to ls1x_dma_filter.
V2:
Change the config from 'DMA_LOONGSON1' to 'LOONGSON1_DMA',
and rearrange it in alphabetical order in Kconfig and Makefile.
Fix comment style.
---
drivers/dma/Kconfig | 9 +
drivers/dma/Makefile | 1 +
drivers/dma/loongson1-dma.c | 546 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 556 insertions(+)
create mode 100644 drivers/dma/loongson1-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 8c98779..852a79e 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -286,6 +286,15 @@ config K3_DMA
Support the DMA engine for Hisilicon K3 platform
devices.

+config LOONGSON1_DMA
+ tristate "Loongson1 DMA support"
+ depends on MACH_LOONGSON32
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ This selects support for the DMA controller in Loongson1 SoCs,
+ and is required by Loongson1 NAND Flash and AC97 support.
+
config LPC18XX_DMAMUX
bool "NXP LPC18xx/43xx DMA MUX for PL080"
depends on ARCH_LPC18XX || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 614f28b..955a5d8 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_INTEL_IOATDMA) += ioat/
obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
obj-$(CONFIG_K3_DMA) += k3dma.o
+obj-$(CONFIG_LOONGSON1_DMA) += loongson1-dma.o
obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o
obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
diff --git a/drivers/dma/loongson1-dma.c b/drivers/dma/loongson1-dma.c
new file mode 100644
index 0000000..edef616
--- /dev/null
+++ b/drivers/dma/loongson1-dma.c
@@ -0,0 +1,546 @@
+/*
+ * DMA Driver for Loongson 1 SoC
+ *
+ * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@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/clk.h>
+#include <linux/dmapool.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dma.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+/* Loongson 1 DMA Register Definitions */
+#define DMA_CTRL 0x0
+
+/* DMA Control Register Bits */
+#define DMA_STOP BIT(4)
+#define DMA_START BIT(3)
+#define ASK_VALID BIT(2)
+
+#define DMA_ADDR_MASK (0xffffffc0)
+
+/* DMA H/W Descriptor Bits */
+#define NEXT_EN BIT(0)
+
+/* DMA Command Register Bits */
+#define DMA_RAM2DEV BIT(12)
+#define DMA_TRANS_OVER BIT(3)
+#define DMA_SINGLE_TRANS_OVER BIT(2)
+#define DMA_INT BIT(1)
+#define DMA_INT_MASK BIT(0)
+
+struct ls1x_dma_hwdesc {
+ u32 next; /* next descriptor address */
+ u32 saddr; /* memory DMA address */
+ u32 daddr; /* device DMA address */
+ u32 length;
+ u32 stride;
+ u32 cycles;
+ u32 cmd;
+ u32 phys; /* used by driver */
+} __aligned(64);
+
+struct ls1x_dma_desc {
+ struct virt_dma_desc vdesc;
+ struct ls1x_dma_chan *chan;
+
+ enum dma_transfer_direction dir;
+ enum dma_transaction_type type;
+
+ unsigned int nr_descs; /* number of descriptors */
+ unsigned int nr_done; /* number of completed descriptors */
+ struct ls1x_dma_hwdesc *desc[0]; /* DMA coherent descriptors */
+};
+
+struct ls1x_dma_chan {
+ struct virt_dma_chan vchan;
+ unsigned int id;
+ void __iomem *reg_base;
+ unsigned int irq;
+ struct dma_pool *desc_pool;
+
+ struct dma_slave_config config;
+
+ struct ls1x_dma_desc *dma_desc;
+ unsigned int curr_hwdesc;
+};
+
+struct ls1x_dma {
+ struct dma_device dma_dev;
+ struct clk *clk;
+ void __iomem *reg_base;
+
+ unsigned int nr_dma_chans;
+ struct ls1x_dma_chan dma_chan[0];
+};
+
+#define to_ls1x_dma_chan(chan) \
+ container_of(chan, struct ls1x_dma_chan, vchan.chan)
+
+#define to_ls1x_dma_desc(vdesc) \
+ container_of(vdesc, struct ls1x_dma_desc, vdesc)
+
+/* macros for registers read/write */
+#define chan_writel(chan, off, val) \
+ __raw_writel((val), (chan)->reg_base + (off))
+
+#define chan_readl(chan, off) \
+ __raw_readl((chan)->reg_base + (off))
+
+bool ls1x_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+ unsigned int chan_id = *(unsigned int *)param;
+
+ if (chan_id == dma_chan->id)
+ return true;
+ else
+ return false;
+}
+
+static void ls1x_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+
+ vchan_free_chan_resources(&dma_chan->vchan);
+ dma_pool_destroy(dma_chan->desc_pool);
+ dma_chan->desc_pool = NULL;
+}
+
+static int ls1x_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+
+ if (dma_chan->desc_pool)
+ return 0;
+
+ dma_chan->desc_pool = dma_pool_create(dma_chan_name(chan),
+ chan->device->dev,
+ sizeof(struct ls1x_dma_hwdesc),
+ __alignof__(struct
+ ls1x_dma_hwdesc), 0);
+ if (!dma_chan->desc_pool) {
+ dev_err(&chan->dev->device,
+ "failed to allocate descriptor pool\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void ls1x_dma_free_desc(struct virt_dma_desc *vdesc)
+{
+ struct ls1x_dma_desc *dma_desc = to_ls1x_dma_desc(vdesc);
+ int i;
+
+ for (i = 0; i < dma_desc->nr_descs; i++)
+ dma_pool_free(dma_desc->chan->desc_pool, dma_desc->desc[i],
+ dma_desc->desc[i]->phys);
+ kfree(dma_desc);
+}
+
+static struct ls1x_dma_desc *ls1x_dma_alloc_desc(struct ls1x_dma_chan *dma_chan,
+ int sg_len)
+{
+ struct ls1x_dma_desc *dma_desc;
+ struct dma_chan *chan = &dma_chan->vchan.chan;
+ dma_addr_t desc_phys;
+ int i;
+
+ dma_desc =
+ kzalloc(sizeof(struct ls1x_dma_desc) +
+ sg_len * sizeof(struct ls1x_dma_hwdesc *), GFP_NOWAIT);
+ if (!dma_desc) {
+ dev_err(&chan->dev->device,
+ "failed to allocate DMA descriptor\n");
+ return NULL;
+ }
+
+ for (i = 0; i < sg_len; i++) {
+ dma_desc->desc[i] = dma_pool_alloc(dma_chan->desc_pool,
+ GFP_NOWAIT, &desc_phys);
+ if (!dma_desc->desc[i])
+ goto err;
+
+ /* memorize the physical address of descriptor */
+ dma_desc->desc[i]->phys = desc_phys;
+ }
+ dma_desc->chan = dma_chan;
+ dma_desc->nr_descs = sg_len;
+ dma_desc->nr_done = 0;
+
+ return dma_desc;
+err:
+ dev_err(&chan->dev->device, "failed to allocate H/W DMA descriptor\n");
+
+ while (--i >= 0)
+ dma_pool_free(dma_chan->desc_pool, dma_desc->desc[i],
+ dma_desc->desc[i]->phys);
+ kfree(dma_desc);
+
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+ls1x_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len,
+ enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+ struct dma_slave_config *config = &dma_chan->config;
+ struct ls1x_dma_desc *dma_desc;
+ struct scatterlist *sg;
+ unsigned int dev_addr, bus_width, cmd, i;
+
+ if (!is_slave_direction(direction)) {
+ dev_err(&chan->dev->device, "invalid DMA direction\n");
+ return NULL;
+ }
+
+ dev_dbg(&chan->dev->device, "sg_len=%d, dir=%s, flags=0x%lx\n", sg_len,
+ direction == DMA_MEM_TO_DEV ? "to device" : "from device",
+ flags);
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ dev_addr = config->dst_addr;
+ bus_width = config->dst_addr_width;
+ cmd = DMA_RAM2DEV | DMA_INT;
+ break;
+ case DMA_DEV_TO_MEM:
+ dev_addr = config->src_addr;
+ bus_width = config->src_addr_width;
+ cmd = DMA_INT;
+ break;
+ default:
+ dev_err(&chan->dev->device,
+ "unsupported DMA transfer mode: %d\n", direction);
+ return NULL;
+ }
+
+ /* allocate DMA descriptors */
+ dma_desc = ls1x_dma_alloc_desc(dma_chan, sg_len);
+ if (!dma_desc)
+ return NULL;
+ dma_desc->dir = direction;
+ dma_desc->type = DMA_SLAVE;
+
+ /* config DMA descriptors */
+ for_each_sg(sgl, sg, sg_len, i) {
+ dma_addr_t buf_addr = sg_dma_address(sg);
+ size_t buf_len = sg_dma_len(sg);
+
+ if (!IS_ALIGNED(buf_addr, 4 * bus_width)) {
+ dev_err(&chan->dev->device,
+ "buf_addr is not aligned on %d-byte boundary\n",
+ 4 * bus_width);
+ ls1x_dma_free_desc(&dma_desc->vdesc);
+ return NULL;
+ }
+
+ if (!IS_ALIGNED(buf_len, bus_width))
+ dev_warn(&chan->dev->device,
+ "buf_len is not aligned on %d-byte boundary\n",
+ bus_width);
+
+ dma_desc->desc[i]->saddr = buf_addr;
+ dma_desc->desc[i]->daddr = dev_addr;
+ dma_desc->desc[i]->length = buf_len / bus_width;
+ dma_desc->desc[i]->stride = 0;
+ dma_desc->desc[i]->cycles = 1;
+ dma_desc->desc[i]->cmd = cmd;
+ dma_desc->desc[i]->next =
+ sg_is_last(sg) ? 0 : dma_desc->desc[i + 1]->phys;
+
+ dev_dbg(&chan->dev->device,
+ "desc=%p, saddr=%08x, daddr=%08x, length=%u\n",
+ &dma_desc->desc[i], buf_addr, dev_addr, buf_len);
+ }
+
+ return vchan_tx_prep(&dma_chan->vchan, &dma_desc->vdesc, flags);
+}
+
+static int ls1x_dma_slave_config(struct dma_chan *chan,
+ struct dma_slave_config *config)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+
+ memcpy(&dma_chan->config, config, sizeof(struct dma_slave_config));
+
+ return 0;
+}
+
+static int ls1x_dma_terminate_all(struct dma_chan *chan)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+ unsigned long flags;
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&dma_chan->vchan.lock, flags);
+
+ chan_writel(dma_chan, DMA_CTRL,
+ chan_readl(dma_chan, DMA_CTRL) | DMA_STOP);
+ dma_chan->dma_desc = NULL;
+ vchan_get_all_descriptors(&dma_chan->vchan, &head);
+
+ spin_unlock_irqrestore(&dma_chan->vchan.lock, flags);
+
+ vchan_dma_desc_free_list(&dma_chan->vchan, &head);
+
+ return 0;
+}
+
+static size_t ls1x_dma_desc_residue(struct ls1x_dma_desc *dma_desc,
+ unsigned int next_sg)
+{
+ struct ls1x_dma_chan *dma_chan = dma_desc->chan;
+ struct dma_slave_config *config = &dma_chan->config;
+ unsigned int i, bus_width, bytes = 0;
+
+ if (dma_desc->dir == DMA_MEM_TO_DEV)
+ bus_width = config->dst_addr_width;
+ else
+ bus_width = config->src_addr_width;
+
+ for (i = next_sg; i < dma_desc->nr_descs; i++)
+ bytes += dma_desc->desc[i]->length * bus_width;
+
+ return bytes;
+}
+
+static enum dma_status ls1x_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+ struct ls1x_dma_desc *dma_desc = dma_chan->dma_desc;
+ struct virt_dma_desc *vdesc;
+ enum dma_status status;
+ unsigned int residue = 0;
+ unsigned long flags;
+
+ status = dma_cookie_status(chan, cookie, txstate);
+ if ((status == DMA_COMPLETE) || !txstate)
+ return status;
+
+ spin_lock_irqsave(&dma_chan->vchan.lock, flags);
+
+ vdesc = vchan_find_desc(&dma_chan->vchan, cookie);
+ if (vdesc)
+ /* not yet processed */
+ residue = ls1x_dma_desc_residue(to_ls1x_dma_desc(vdesc), 0);
+ else if (cookie == dma_chan->dma_desc->vdesc.tx.cookie)
+ /* in progress */
+ residue = ls1x_dma_desc_residue(dma_desc, dma_desc->nr_done);
+ else
+ residue = 0;
+
+ spin_unlock_irqrestore(&dma_chan->vchan.lock, flags);
+
+ dma_set_residue(txstate, residue);
+
+ return status;
+}
+
+static void ls1x_trigger_dma(struct ls1x_dma_chan *dma_chan)
+{
+ struct dma_chan *chan = &dma_chan->vchan.chan;
+ struct ls1x_dma_desc *dma_desc;
+ struct virt_dma_desc *vdesc;
+ unsigned int val;
+
+ vdesc = vchan_next_desc(&dma_chan->vchan);
+ if (!vdesc) {
+ dev_warn(&chan->dev->device, "No pending descriptor\n");
+ return;
+ }
+ dma_chan->dma_desc = dma_desc = to_ls1x_dma_desc(vdesc);
+
+ dev_dbg(&chan->dev->device, "cookie=%d, %u descs, starting desc=%p\n",
+ chan->cookie, dma_desc->nr_descs, &dma_desc->desc[0]);
+
+ val = dma_desc->desc[0]->phys & DMA_ADDR_MASK;
+ val |= dma_chan->id;
+ val |= DMA_START;
+ chan_writel(dma_chan, DMA_CTRL, val);
+}
+
+static void ls1x_dma_issue_pending(struct dma_chan *chan)
+{
+ struct ls1x_dma_chan *dma_chan = to_ls1x_dma_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&dma_chan->vchan.lock, flags);
+
+ if (vchan_issue_pending(&dma_chan->vchan) && !dma_chan->dma_desc)
+ ls1x_trigger_dma(dma_chan);
+
+ spin_unlock_irqrestore(&dma_chan->vchan.lock, flags);
+}
+
+static irqreturn_t ls1x_dma_irq_handler(int irq, void *data)
+{
+ struct ls1x_dma_chan *dma_chan = data;
+ struct dma_chan *chan = &dma_chan->vchan.chan;
+
+ dev_dbg(&chan->dev->device, "DMA IRQ %d on channel %d\n", irq,
+ dma_chan->id);
+ if (!dma_chan->dma_desc) {
+ dev_warn(&chan->dev->device,
+ "DMA IRQ with no active descriptor on channel %d\n",
+ dma_chan->id);
+ return IRQ_NONE;
+ }
+
+ spin_lock(&dma_chan->vchan.lock);
+
+ if (dma_chan->dma_desc->type == DMA_CYCLIC) {
+ vchan_cyclic_callback(&dma_chan->dma_desc->vdesc);
+ } else {
+ list_del(&dma_chan->dma_desc->vdesc.node);
+ vchan_cookie_complete(&dma_chan->dma_desc->vdesc);
+ dma_chan->dma_desc = NULL;
+ }
+
+ spin_unlock(&dma_chan->vchan.lock);
+ return IRQ_HANDLED;
+}
+
+static int ls1x_dma_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct plat_ls1x_dma *pdata = dev_get_platdata(dev);
+ struct dma_device *dma_dev;
+ struct ls1x_dma *dma;
+ struct ls1x_dma_chan *dma_chan;
+ struct resource *res;
+ int i, ret;
+
+ /* initialize DMA device */
+ dma =
+ devm_kzalloc(dev,
+ sizeof(struct ls1x_dma) +
+ pdata->nr_channels * sizeof(struct ls1x_dma_chan),
+ GFP_KERNEL);
+ if (!dma)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "failed to get I/O memory\n");
+ return -EINVAL;
+ }
+
+ dma->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(dma->reg_base))
+ return PTR_ERR(dma->reg_base);
+
+ dma_dev = &dma->dma_dev;
+
+ dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+ dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+
+ dma_dev->dev = dev;
+ dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+ dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
+ dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+ dma_dev->device_alloc_chan_resources = ls1x_dma_alloc_chan_resources;
+ dma_dev->device_free_chan_resources = ls1x_dma_free_chan_resources;
+ dma_dev->device_prep_slave_sg = ls1x_dma_prep_slave_sg;
+ dma_dev->device_config = ls1x_dma_slave_config;
+ dma_dev->device_terminate_all = ls1x_dma_terminate_all;
+ dma_dev->device_tx_status = ls1x_dma_tx_status;
+ dma_dev->device_issue_pending = ls1x_dma_issue_pending;
+
+ INIT_LIST_HEAD(&dma_dev->channels);
+
+ /* initialize DMA channels */
+ for (i = 0; i < pdata->nr_channels; i++) {
+ dma_chan = &dma->dma_chan[i];
+ dma_chan->id = i;
+ dma_chan->reg_base = dma->reg_base;
+
+ dma_chan->irq = platform_get_irq(pdev, i);
+ if (dma_chan->irq < 0) {
+ dev_err(dev, "failed to get IRQ: %d\n", dma_chan->irq);
+ return -EINVAL;
+ }
+
+ ret =
+ devm_request_irq(dev, dma_chan->irq, ls1x_dma_irq_handler,
+ IRQF_SHARED, dev_name(dev), dma_chan);
+ if (ret) {
+ dev_err(dev, "failed to request IRQ %u!\n",
+ dma_chan->irq);
+ return -EINVAL;
+ }
+
+ dma_chan->vchan.desc_free = ls1x_dma_free_desc;
+ vchan_init(&dma_chan->vchan, dma_dev);
+ }
+ dma->nr_dma_chans = i;
+
+ dma->clk = devm_clk_get(dev, pdev->name);
+ if (IS_ERR(dma->clk)) {
+ dev_err(dev, "failed to get %s clock\n", pdev->name);
+ return PTR_ERR(dma->clk);
+ }
+ clk_prepare_enable(dma->clk);
+
+ ret = dma_async_device_register(dma_dev);
+ if (ret) {
+ dev_err(dev, "failed to register DMA device\n");
+ clk_disable_unprepare(dma->clk);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, dma);
+ dev_info(dev, "Loongson1 DMA driver registered\n");
+ for (i = 0; i < pdata->nr_channels; i++) {
+ dma_chan = &dma->dma_chan[i];
+ dev = &dma_chan->vchan.chan.dev->device;
+ dev_info(dev, "channel %d at 0x%p (irq %d)\n", dma_chan->id,
+ dma_chan->reg_base, dma_chan->irq);
+ }
+
+ return 0;
+}
+
+static int ls1x_dma_remove(struct platform_device *pdev)
+{
+ struct ls1x_dma *dma = platform_get_drvdata(pdev);
+
+ dma_async_device_unregister(&dma->dma_dev);
+ clk_disable_unprepare(dma->clk);
+ return 0;
+}
+
+static struct platform_driver ls1x_dma_driver = {
+ .probe = ls1x_dma_probe,
+ .remove = ls1x_dma_remove,
+ .driver = {
+ .name = "ls1x-dma",
+ },
+};
+
+module_platform_driver(ls1x_dma_driver);
+
+MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 DMA driver");
+MODULE_LICENSE("GPL");
--
1.9.1
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  Last update: 2016-05-28 12:01    [W:0.062 / U:1.384 seconds]
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