[PATCH v3 2/2] dmaengine: milbeaut-xdmac: Add XDMAC driver for Milbeaut platforms

jassisinghbrar
2019-10-15T03:32:19Z

Driver for Socionext Milbeaut XDMAC controller. The controller only
supports Mem-To-Mem transfers over upto 8 configurable channels.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
drivers/dma/Kconfig | 10 +
drivers/dma/Makefile | 1 +
drivers/dma/milbeaut-xdmac.c | 418 +++++++++++++++++++++++++++++++++++
3 files changed, 429 insertions(+)
create mode 100644 drivers/dma/milbeaut-xdmac.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index d312ebbafbee..a34cd5a72a7b 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -352,6 +352,16 @@ config MILBEAUT_HDMAC
Say yes here to support the Socionext Milbeaut
HDMAC device.

+config MILBEAUT_XDMAC
+ tristate "Milbeaut AXI DMA support"
+ depends on ARCH_MILBEAUT || COMPILE_TEST
+ depends on OF
+ select DMA_ENGINE
+ select DMA_VIRTUAL_CHANNELS
+ help
+ Say yes here to support the Socionext Milbeaut
+ XDMAC device.
+
config MMP_PDMA
bool "MMP PDMA support"
depends on ARCH_MMP || ARCH_PXA || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 5f0df3611414..e3a8fdf80c76 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
obj-$(CONFIG_K3_DMA) += k3dma.o
obj-$(CONFIG_LPC18XX_DMAMUX) += lpc18xx-dmamux.o
obj-$(CONFIG_MILBEAUT_HDMAC) += milbeaut-hdmac.o
+obj-$(CONFIG_MILBEAUT_XDMAC) += milbeaut-xdmac.o
obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
obj-$(CONFIG_MOXART_DMA) += moxart-dma.o
diff --git a/drivers/dma/milbeaut-xdmac.c b/drivers/dma/milbeaut-xdmac.c
new file mode 100644
index 000000000000..3d5b1926a58d
--- /dev/null
+++ b/drivers/dma/milbeaut-xdmac.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2019 Linaro Ltd.
+// Copyright (C) 2019 Socionext Inc.
+
+#include <linux/bits.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/bitfield.h>
+
+#include "virt-dma.h"
+
+/* global register */
+#define M10V_XDACS 0x00
+
+/* channel local register */
+#define M10V_XDTBC 0x10
+#define M10V_XDSSA 0x14
+#define M10V_XDDSA 0x18
+#define M10V_XDSAC 0x1C
+#define M10V_XDDAC 0x20
+#define M10V_XDDCC 0x24
+#define M10V_XDDES 0x28
+#define M10V_XDDPC 0x2C
+#define M10V_XDDSD 0x30
+
+#define M10V_XDACS_XE BIT(28)
+
+#define M10V_DEFBS 0x3
+#define M10V_DEFBL 0xf
+
+#define M10V_XDSAC_SBS GENMASK(17, 16)
+#define M10V_XDSAC_SBL GENMASK(11, 8)
+
+#define M10V_XDDAC_DBS GENMASK(17, 16)
+#define M10V_XDDAC_DBL GENMASK(11, 8)
+
+#define M10V_XDDES_CE BIT(28)
+#define M10V_XDDES_SE BIT(24)
+#define M10V_XDDES_SA BIT(15)
+#define M10V_XDDES_TF GENMASK(23, 20)
+#define M10V_XDDES_EI BIT(1)
+#define M10V_XDDES_TI BIT(0)
+
+#define M10V_XDDSD_IS_MASK GENMASK(3, 0)
+#define M10V_XDDSD_IS_NORMAL 0x8
+
+#define MLB_XDMAC_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
+
+struct milbeaut_xdmac_desc {
+ struct virt_dma_desc vd;
+ size_t len;
+ dma_addr_t src;
+ dma_addr_t dst;
+};
+
+struct milbeaut_xdmac_chan {
+ struct virt_dma_chan vc;
+ struct milbeaut_xdmac_desc *md;
+ void __iomem *reg_ch_base;
+};
+
+struct milbeaut_xdmac_device {
+ struct dma_device ddev;
+ void __iomem *reg_base;
+ struct milbeaut_xdmac_chan channels[0];
+};
+
+static struct milbeaut_xdmac_chan *
+to_milbeaut_xdmac_chan(struct virt_dma_chan *vc)
+{
+ return container_of(vc, struct milbeaut_xdmac_chan, vc);
+}
+
+static struct milbeaut_xdmac_desc *
+to_milbeaut_xdmac_desc(struct virt_dma_desc *vd)
+{
+ return container_of(vd, struct milbeaut_xdmac_desc, vd);
+}
+
+/* mc->vc.lock must be held by caller */
+static struct milbeaut_xdmac_desc *
+milbeaut_xdmac_next_desc(struct milbeaut_xdmac_chan *mc)
+{
+ struct virt_dma_desc *vd;
+
+ vd = vchan_next_desc(&mc->vc);
+ if (!vd) {
+ mc->md = NULL;
+ return NULL;
+ }
+
+ list_del(&vd->node);
+
+ mc->md = to_milbeaut_xdmac_desc(vd);
+
+ return mc->md;
+}
+
+/* mc->vc.lock must be held by caller */
+static void milbeaut_chan_start(struct milbeaut_xdmac_chan *mc,
+ struct milbeaut_xdmac_desc *md)
+{
+ u32 val;
+
+ /* Setup the channel */
+ val = md->len - 1;
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDTBC);
+
+ val = md->src;
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDSSA);
+
+ val = md->dst;
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDDSA);
+
+ val = readl_relaxed(mc->reg_ch_base + M10V_XDSAC);
+ val &= ~(M10V_XDSAC_SBS | M10V_XDSAC_SBL);
+ val |= FIELD_PREP(M10V_XDSAC_SBS, M10V_DEFBS) |
+ FIELD_PREP(M10V_XDSAC_SBL, M10V_DEFBL);
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDSAC);
+
+ val = readl_relaxed(mc->reg_ch_base + M10V_XDDAC);
+ val &= ~(M10V_XDDAC_DBS | M10V_XDDAC_DBL);
+ val |= FIELD_PREP(M10V_XDDAC_DBS, M10V_DEFBS) |
+ FIELD_PREP(M10V_XDDAC_DBL, M10V_DEFBL);
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDDAC);
+
+ /* Start the channel */
+ val = readl_relaxed(mc->reg_ch_base + M10V_XDDES);
+ val &= ~(M10V_XDDES_CE | M10V_XDDES_SE | M10V_XDDES_TF |
+ M10V_XDDES_EI | M10V_XDDES_TI);
+ val |= FIELD_PREP(M10V_XDDES_CE, 1) | FIELD_PREP(M10V_XDDES_SE, 1) |
+ FIELD_PREP(M10V_XDDES_TF, 1) | FIELD_PREP(M10V_XDDES_EI, 1) |
+ FIELD_PREP(M10V_XDDES_TI, 1);
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDDES);
+}
+
+/* mc->vc.lock must be held by caller */
+static void milbeaut_xdmac_start(struct milbeaut_xdmac_chan *mc)
+{
+ struct milbeaut_xdmac_desc *md;
+
+ md = milbeaut_xdmac_next_desc(mc);
+ if (md)
+ milbeaut_chan_start(mc, md);
+}
+
+static irqreturn_t milbeaut_xdmac_interrupt(int irq, void *dev_id)
+{
+ struct milbeaut_xdmac_chan *mc = dev_id;
+ struct milbeaut_xdmac_desc *md;
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&mc->vc.lock, flags);
+
+ /* Ack and Stop */
+ val = FIELD_PREP(M10V_XDDSD_IS_MASK, 0x0);
+ writel_relaxed(val, mc->reg_ch_base + M10V_XDDSD);
+
+ md = mc->md;
+ if (!md)
+ goto out;
+
+ vchan_cookie_complete(&md->vd);
+
+ milbeaut_xdmac_start(mc);
+out:
+ spin_unlock_irqrestore(&mc->vc.lock, flags);
+ return IRQ_HANDLED;
+}
+
+static void milbeaut_xdmac_free_chan_resources(struct dma_chan *chan)
+{
+ vchan_free_chan_resources(to_virt_chan(chan));
+}
+
+static struct dma_async_tx_descriptor *
+milbeaut_xdmac_prep_memcpy(struct dma_chan *chan, dma_addr_t dst,
+ dma_addr_t src, size_t len, unsigned long flags)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_xdmac_desc *md;
+
+ md = kzalloc(sizeof(*md), GFP_NOWAIT);
+ if (!md)
+ return NULL;
+
+ md->len = len;
+ md->src = src;
+ md->dst = dst;
+
+ return vchan_tx_prep(vc, &md->vd, flags);
+}
+
+static int milbeaut_xdmac_terminate_all(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
+ unsigned long flags;
+ u32 val;
+
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ /* Halt the channel */
+ val = readl(mc->reg_ch_base + M10V_XDDES);
+ val &= ~M10V_XDDES_CE;
+ val |= FIELD_PREP(M10V_XDDES_CE, 0);
+ writel(val, mc->reg_ch_base + M10V_XDDES);
+
+ if (mc->md) {
+ vchan_terminate_vdesc(&mc->md->vd);
+ mc->md = NULL;
+ }
+
+ vchan_get_all_descriptors(vc, &head);
+
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ vchan_dma_desc_free_list(vc, &head);
+
+ return 0;
+}
+
+static void milbeaut_xdmac_synchronize(struct dma_chan *chan)
+{
+ vchan_synchronize(to_virt_chan(chan));
+}
+
+static void milbeaut_xdmac_issue_pending(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_xdmac_chan *mc = to_milbeaut_xdmac_chan(vc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ if (vchan_issue_pending(vc) && !mc->md)
+ milbeaut_xdmac_start(mc);
+
+ spin_unlock_irqrestore(&vc->lock, flags);
+}
+
+static void milbeaut_xdmac_desc_free(struct virt_dma_desc *vd)
+{
+ kfree(to_milbeaut_xdmac_desc(vd));
+}
+
+static int milbeaut_xdmac_chan_init(struct platform_device *pdev,
+ struct milbeaut_xdmac_device *mdev,
+ int chan_id)
+{
+ struct device *dev = &pdev->dev;
+ struct milbeaut_xdmac_chan *mc = &mdev->channels[chan_id];
+ char *irq_name;
+ int irq, ret;
+
+ irq = platform_get_irq(pdev, chan_id);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n",
+ chan_id);
+ return irq;
+ }
+
+ irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-xdmac-%d",
+ chan_id);
+ if (!irq_name)
+ return -ENOMEM;
+
+ ret = devm_request_irq(dev, irq, milbeaut_xdmac_interrupt,
+ IRQF_SHARED, irq_name, mc);
+ if (ret)
+ return ret;
+
+ mc->reg_ch_base = mdev->reg_base + chan_id * 0x30;
+
+ mc->vc.desc_free = milbeaut_xdmac_desc_free;
+ vchan_init(&mc->vc, &mdev->ddev);
+
+ return 0;
+}
+
+static void enable_xdmac(struct milbeaut_xdmac_device *mdev)
+{
+ unsigned int val;
+
+ val = readl(mdev->reg_base + M10V_XDACS);
+ val |= M10V_XDACS_XE;
+ writel(val, mdev->reg_base + M10V_XDACS);
+}
+
+static void disable_xdmac(struct milbeaut_xdmac_device *mdev)
+{
+ unsigned int val;
+
+ val = readl(mdev->reg_base + M10V_XDACS);
+ val &= ~M10V_XDACS_XE;
+ writel(val, mdev->reg_base + M10V_XDACS);
+}
+
+static int milbeaut_xdmac_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct milbeaut_xdmac_device *mdev;
+ struct dma_device *ddev;
+ int nr_chans, ret, i;
+
+ nr_chans = platform_irq_count(pdev);
+ if (nr_chans < 0)
+ return nr_chans;
+
+ mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
+ GFP_KERNEL);
+ if (!mdev)
+ return -ENOMEM;
+
+ mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(mdev->reg_base))
+ return PTR_ERR(mdev->reg_base);
+
+ ddev = &mdev->ddev;
+ ddev->dev = dev;
+ dma_cap_set(DMA_MEMCPY, ddev->cap_mask);
+ ddev->src_addr_widths = MLB_XDMAC_BUSWIDTHS;
+ ddev->dst_addr_widths = MLB_XDMAC_BUSWIDTHS;
+ ddev->device_free_chan_resources = milbeaut_xdmac_free_chan_resources;
+ ddev->device_prep_dma_memcpy = milbeaut_xdmac_prep_memcpy;
+ ddev->device_terminate_all = milbeaut_xdmac_terminate_all;
+ ddev->device_synchronize = milbeaut_xdmac_synchronize;
+ ddev->device_tx_status = dma_cookie_status;
+ ddev->device_issue_pending = milbeaut_xdmac_issue_pending;
+ INIT_LIST_HEAD(&ddev->channels);
+
+ for (i = 0; i < nr_chans; i++) {
+ ret = milbeaut_xdmac_chan_init(pdev, mdev, i);
+ if (ret)
+ return ret;
+ }
+
+ enable_xdmac(mdev);
+
+ ret = dma_async_device_register(ddev);
+ if (ret)
+ return ret;
+
+ ret = of_dma_controller_register(dev->of_node,
+ of_dma_simple_xlate, mdev);
+ if (ret)
+ goto unregister_dmac;
+
+ platform_set_drvdata(pdev, mdev);
+
+ return 0;
+
+unregister_dmac:
+ dma_async_device_unregister(ddev);
+ return ret;
+}
+
+static int milbeaut_xdmac_remove(struct platform_device *pdev)
+{
+ struct milbeaut_xdmac_device *mdev = platform_get_drvdata(pdev);
+ struct dma_chan *chan;
+ int ret;
+
+ /*
+ * Before reaching here, almost all descriptors have been freed by the
+ * ->device_free_chan_resources() hook. However, each channel might
+ * be still holding one descriptor that was on-flight at that moment.
+ * Terminate it to make sure this hardware is no longer running. Then,
+ * free the channel resources once again to avoid memory leak.
+ */
+ list_for_each_entry(chan, &mdev->ddev.channels, device_node) {
+ ret = dmaengine_terminate_sync(chan);
+ if (ret)
+ return ret;
+ milbeaut_xdmac_free_chan_resources(chan);
+ }
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&mdev->ddev);
+
+ disable_xdmac(mdev);
+
+ return 0;
+}
+
+static const struct of_device_id milbeaut_xdmac_match[] = {
+ { .compatible = "socionext,milbeaut-m10v-xdmac" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, milbeaut_xdmac_match);
+
+static struct platform_driver milbeaut_xdmac_driver = {
+ .probe = milbeaut_xdmac_probe,
+ .remove = milbeaut_xdmac_remove,
+ .driver = {
+ .name = "milbeaut-m10v-xdmac",
+ .of_match_table = milbeaut_xdmac_match,
+ },
+};
+module_platform_driver(milbeaut_xdmac_driver);
+
+MODULE_DESCRIPTION("Milbeaut XDMAC DmaEngine driver");
+MODULE_LICENSE("GPL v2");
--
2.20.1