[PATCH 2/2] dmaengine: milbeaut-hdmac: Add HDMAC driver for Milbeaut platforms

jassisinghbrar
2019-06-13T00:52:47Z

From: Jassi Brar <jaswinder.singh@linaro.org>

Driver for Socionext Milbeaut HDMAC controller. The controller has
upto 8 floating channels, that need a predefined slave-id to work
from a set of slaves.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
drivers/dma/Kconfig | 10 +
drivers/dma/Makefile | 1 +
drivers/dma/milbeaut-hdmac.c | 572 +++++++++++++++++++++++++++++++++++
3 files changed, 583 insertions(+)
create mode 100644 drivers/dma/milbeaut-hdmac.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 703275cc29de..15a1d5263ca1 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -347,6 +347,16 @@ config MCF_EDMA
minimal intervention from a host processor.
This module can be found on Freescale ColdFire mcf5441x SoCs.

+config MILBEAUT_HDMAC
+ tristate "Milbeaut AHB 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
+ HDMAC 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 6126e1c3a875..d0a9f46726e8 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -45,6 +45,7 @@ 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_LPC18XX_DMAMUX) += lpc18xx-dmamux.o
+obj-$(CONFIG_MILBEAUT_HDMAC) += milbeaut-hdmac.o
obj-$(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-hdmac.c b/drivers/dma/milbeaut-hdmac.c
new file mode 100644
index 000000000000..9c9fabdf8cdc
--- /dev/null
+++ b/drivers/dma/milbeaut-hdmac.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (C) 2019 Linaro Ltd.
+// Copyright (C) 2019 Socionext Inc.
+
+#include <linux/bits.h>
+#include <linux/clk.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.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"
+
+#define MLB_HDMAC_DMACR 0x0 /* global */
+#define MLB_HDMAC_DE BIT(31)
+#define MLB_HDMAC_DS BIT(30)
+#define MLB_HDMAC_PR BIT(28)
+#define MLB_HDMAC_DH GENMASK(27, 24)
+
+#define MLB_HDMAC_CH_STRIDE 0x10
+
+#define MLB_HDMAC_DMACA 0x0 /* channel */
+#define MLB_HDMAC_EB BIT(31)
+#define MLB_HDMAC_PB BIT(30)
+#define MLB_HDMAC_ST BIT(29)
+#define MLB_HDMAC_IS GENMASK(28, 24)
+#define MLB_HDMAC_BT GENMASK(23, 20)
+#define MLB_HDMAC_BC GENMASK(19, 16)
+#define MLB_HDMAC_TC GENMASK(15, 0)
+#define MLB_HDMAC_DMACB 0x4
+#define MLB_HDMAC_TT GENMASK(31, 30)
+#define MLB_HDMAC_MS GENMASK(29, 28)
+#define MLB_HDMAC_TW GENMASK(27, 26)
+#define MLB_HDMAC_FS BIT(25)
+#define MLB_HDMAC_FD BIT(24)
+#define MLB_HDMAC_RC BIT(23)
+#define MLB_HDMAC_RS BIT(22)
+#define MLB_HDMAC_RD BIT(21)
+#define MLB_HDMAC_EI BIT(20)
+#define MLB_HDMAC_CI BIT(19)
+#define MLB_HDMAC_SS GENMASK(18, 16)
+#define MLB_HDMAC_SP GENMASK(15, 12)
+#define MLB_HDMAC_DP GENMASK(11, 8)
+#define MLB_HDMAC_DMACSA 0x8
+#define MLB_HDMAC_DMACDA 0xc
+
+#define MLB_HDMAC_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
+
+struct milbeaut_hdmac_desc {
+ struct virt_dma_desc vd;
+ struct scatterlist *sgl;
+ unsigned int sg_len;
+ unsigned int sg_cur;
+ enum dma_transfer_direction dir;
+};
+
+struct milbeaut_hdmac_chan {
+ struct virt_dma_chan vc;
+ struct milbeaut_hdmac_device *mdev;
+ struct milbeaut_hdmac_desc *md;
+ void __iomem *reg_ch_base;
+ unsigned int slave_id;
+ struct dma_slave_config cfg;
+};
+
+struct milbeaut_hdmac_device {
+ struct dma_device ddev;
+ struct clk *clk;
+ void __iomem *reg_base;
+ struct milbeaut_hdmac_chan channels[0];
+};
+
+static struct milbeaut_hdmac_chan *
+to_milbeaut_hdmac_chan(struct virt_dma_chan *vc)
+{
+ return container_of(vc, struct milbeaut_hdmac_chan, vc);
+}
+
+static struct milbeaut_hdmac_desc *
+to_milbeaut_hdmac_desc(struct virt_dma_desc *vd)
+{
+ return container_of(vd, struct milbeaut_hdmac_desc, vd);
+}
+
+/* mc->vc.lock must be held by caller */
+static struct milbeaut_hdmac_desc *
+milbeaut_hdmac_next_desc(struct milbeaut_hdmac_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_hdmac_desc(vd);
+
+ return mc->md;
+}
+
+/* mc->vc.lock must be held by caller */
+static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc,
+ struct milbeaut_hdmac_desc *md)
+{
+ struct scatterlist *sg;
+ u32 cb, ca, src_addr, dest_addr, len;
+ u32 width, burst;
+
+ sg = &md->sgl[md->sg_cur];
+ len = sg_dma_len(sg);
+
+ cb = MLB_HDMAC_CI | MLB_HDMAC_EI;
+ if (md->dir == DMA_MEM_TO_DEV) {
+ cb |= MLB_HDMAC_FD;
+ width = mc->cfg.dst_addr_width;
+ burst = mc->cfg.dst_maxburst;
+ src_addr = sg_dma_address(sg);
+ dest_addr = mc->cfg.dst_addr;
+ } else {
+ cb |= MLB_HDMAC_FS;
+ width = mc->cfg.src_addr_width;
+ burst = mc->cfg.src_maxburst;
+ src_addr = mc->cfg.src_addr;
+ dest_addr = sg_dma_address(sg);
+ }
+ cb |= FIELD_PREP(MLB_HDMAC_TW, (width >> 1));
+ cb |= FIELD_PREP(MLB_HDMAC_MS, 2);
+
+ writel_relaxed(src_addr, mc->reg_ch_base + MLB_HDMAC_DMACSA);
+ writel_relaxed(dest_addr, mc->reg_ch_base + MLB_HDMAC_DMACDA);
+ writel_relaxed(cb, mc->reg_ch_base + MLB_HDMAC_DMACB);
+
+ ca = FIELD_PREP(MLB_HDMAC_IS, mc->slave_id);
+ if (burst == 16)
+ ca |= FIELD_PREP(MLB_HDMAC_BT, 0xf);
+ else if (burst == 8)
+ ca |= FIELD_PREP(MLB_HDMAC_BT, 0xd);
+ else if (burst == 4)
+ ca |= FIELD_PREP(MLB_HDMAC_BT, 0xb);
+ burst *= width;
+ ca |= FIELD_PREP(MLB_HDMAC_TC, (len / burst - 1));
+ writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
+ ca |= MLB_HDMAC_EB;
+ writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
+}
+
+/* mc->vc.lock must be held by caller */
+static void milbeaut_hdmac_start(struct milbeaut_hdmac_chan *mc)
+{
+ struct milbeaut_hdmac_desc *md;
+
+ md = milbeaut_hdmac_next_desc(mc);
+ if (md)
+ milbeaut_chan_start(mc, md);
+}
+
+static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id)
+{
+ struct milbeaut_hdmac_chan *mc = dev_id;
+ struct milbeaut_hdmac_desc *md;
+ irqreturn_t ret = IRQ_HANDLED;
+ u32 val;
+
+ spin_lock(&mc->vc.lock);
+
+ /* Ack and Disable irqs */
+ val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB);
+ val &= ~(FIELD_PREP(MLB_HDMAC_SS, 0x7));
+ writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
+ val &= ~MLB_HDMAC_EI;
+ val &= ~MLB_HDMAC_CI;
+ writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
+
+ md = mc->md;
+ if (!md)
+ goto out;
+
+ md->sg_cur++;
+
+ if (md->sg_cur >= md->sg_len) {
+ vchan_cookie_complete(&md->vd);
+ md = milbeaut_hdmac_next_desc(mc);
+ if (!md)
+ goto out;
+ }
+
+ milbeaut_chan_start(mc, md);
+
+out:
+ spin_unlock(&mc->vc.lock);
+ return ret;
+}
+
+static void milbeaut_hdmac_free_chan_resources(struct dma_chan *chan)
+{
+ vchan_free_chan_resources(to_virt_chan(chan));
+}
+
+static int
+milbeaut_hdmac_chan_config(struct dma_chan *chan, struct dma_slave_config *cfg)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
+
+ spin_lock(&mc->vc.lock);
+ mc->cfg = *cfg;
+ spin_unlock(&mc->vc.lock);
+
+ return 0;
+}
+
+static int milbeaut_hdmac_chan_pause(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
+ u32 val;
+
+ spin_lock(&mc->vc.lock);
+ val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
+ val |= MLB_HDMAC_PB;
+ writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
+ spin_unlock(&mc->vc.lock);
+
+ return 0;
+}
+
+static int milbeaut_hdmac_chan_resume(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
+ u32 val;
+
+ spin_lock(&mc->vc.lock);
+ val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
+ val &= ~MLB_HDMAC_PB;
+ writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
+ spin_unlock(&mc->vc.lock);
+
+ return 0;
+}
+
+static struct dma_async_tx_descriptor *
+milbeaut_hdmac_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 virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_desc *md;
+
+ if (!is_slave_direction(direction))
+ return NULL;
+
+ md = kzalloc(sizeof(*md), GFP_NOWAIT);
+ if (!md)
+ return NULL;
+
+ md->sgl = sgl;
+ md->sg_len = sg_len;
+ md->dir = direction;
+
+ return vchan_tx_prep(vc, &md->vd, flags);
+}
+
+static int milbeaut_hdmac_terminate_all(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
+ unsigned long flags;
+ int ret = 0;
+ u32 val;
+
+ LIST_HEAD(head);
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
+ val &= ~MLB_HDMAC_EB; /* disable the channel */
+ writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
+
+ 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 ret;
+}
+
+static void milbeaut_hdmac_synchronize(struct dma_chan *chan)
+{
+ vchan_synchronize(to_virt_chan(chan));
+}
+
+static enum dma_status milbeaut_hdmac_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie,
+ struct dma_tx_state *txstate)
+{
+ struct virt_dma_chan *vc;
+ struct virt_dma_desc *vd;
+ struct milbeaut_hdmac_chan *mc;
+ struct milbeaut_hdmac_desc *md = NULL;
+ enum dma_status stat;
+ unsigned long flags;
+ int i;
+
+ stat = dma_cookie_status(chan, cookie, txstate);
+ /* Return immediately if we do not need to compute the residue. */
+ if (stat == DMA_COMPLETE || !txstate)
+ return stat;
+
+ vc = to_virt_chan(chan);
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ mc = to_milbeaut_hdmac_chan(vc);
+
+ /* residue from the on-flight chunk */
+ if (mc->md && mc->md->vd.tx.cookie == cookie) {
+ struct scatterlist *sg;
+ u32 done;
+
+ md = mc->md;
+ sg = &md->sgl[md->sg_cur];
+
+ if (md->dir == DMA_DEV_TO_MEM)
+ done = readl_relaxed(mc->reg_ch_base
+ + MLB_HDMAC_DMACDA);
+ else
+ done = readl_relaxed(mc->reg_ch_base
+ + MLB_HDMAC_DMACSA);
+ done -= sg_dma_address(sg);
+
+ txstate->residue = -done;
+ }
+
+ if (!md) {
+ vd = vchan_find_desc(vc, cookie);
+ if (vd)
+ md = to_milbeaut_hdmac_desc(vd);
+ }
+
+ if (md) {
+ /* residue from the queued chunks */
+ for (i = md->sg_cur; i < md->sg_len; i++)
+ txstate->residue += sg_dma_len(&md->sgl[i]);
+ }
+
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ return stat;
+}
+
+static void milbeaut_hdmac_issue_pending(struct dma_chan *chan)
+{
+ struct virt_dma_chan *vc = to_virt_chan(chan);
+ struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vc->lock, flags);
+
+ if (vchan_issue_pending(vc) && !mc->md)
+ milbeaut_hdmac_start(mc);
+
+ spin_unlock_irqrestore(&vc->lock, flags);
+}
+
+static void milbeaut_hdmac_desc_free(struct virt_dma_desc *vd)
+{
+ kfree(to_milbeaut_hdmac_desc(vd));
+}
+
+static struct dma_chan *
+milbeaut_hdmac_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma)
+{
+ struct milbeaut_hdmac_device *mdev = of_dma->of_dma_data;
+ struct milbeaut_hdmac_chan *mc;
+ struct virt_dma_chan *vc;
+ struct dma_chan *chan;
+
+ if (dma_spec->args_count != 1)
+ return NULL;
+
+ chan = dma_get_any_slave_channel(&mdev->ddev);
+ if (!chan)
+ return NULL;
+
+ vc = to_virt_chan(chan);
+ mc = to_milbeaut_hdmac_chan(vc);
+ mc->slave_id = dma_spec->args[0];
+
+ return chan;
+}
+
+static int milbeaut_hdmac_chan_init(struct platform_device *pdev,
+ struct milbeaut_hdmac_device *mdev,
+ int chan_id)
+{
+ struct device *dev = &pdev->dev;
+ struct milbeaut_hdmac_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-hdmac-%d",
+ chan_id);
+ if (!irq_name)
+ return -ENOMEM;
+
+ ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt,
+ IRQF_SHARED, irq_name, mc);
+ if (ret)
+ return ret;
+
+ mc->mdev = mdev;
+ mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1);
+ mc->vc.desc_free = milbeaut_hdmac_desc_free;
+ vchan_init(&mc->vc, &mdev->ddev);
+
+ return 0;
+}
+
+static int milbeaut_hdmac_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct milbeaut_hdmac_device *mdev;
+ struct dma_device *ddev;
+ struct resource *res;
+ int nr_chans, ret, i;
+
+ nr_chans = platform_irq_count(pdev);
+ if (nr_chans < 0)
+ return nr_chans;
+
+ ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+
+ mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
+ GFP_KERNEL);
+ if (!mdev)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mdev->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mdev->reg_base))
+ return PTR_ERR(mdev->reg_base);
+
+ mdev->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(mdev->clk)) {
+ dev_err(dev, "failed to get clock\n");
+ return PTR_ERR(mdev->clk);
+ }
+
+ ret = clk_prepare_enable(mdev->clk);
+ if (ret)
+ return ret;
+
+ ddev = &mdev->ddev;
+ ddev->dev = dev;
+ dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
+ ddev->src_addr_widths = MLB_HDMAC_BUSWIDTHS;
+ ddev->dst_addr_widths = MLB_HDMAC_BUSWIDTHS;
+ ddev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
+ ddev->device_free_chan_resources = milbeaut_hdmac_free_chan_resources;
+ ddev->device_config = milbeaut_hdmac_chan_config;
+ ddev->device_pause = milbeaut_hdmac_chan_pause;
+ ddev->device_resume = milbeaut_hdmac_chan_resume;
+ ddev->device_prep_slave_sg = milbeaut_hdmac_prep_slave_sg;
+ ddev->device_terminate_all = milbeaut_hdmac_terminate_all;
+ ddev->device_synchronize = milbeaut_hdmac_synchronize;
+ ddev->device_tx_status = milbeaut_hdmac_tx_status;
+ ddev->device_issue_pending = milbeaut_hdmac_issue_pending;
+ INIT_LIST_HEAD(&ddev->channels);
+
+ for (i = 0; i < nr_chans; i++) {
+ ret = milbeaut_hdmac_chan_init(pdev, mdev, i);
+ if (ret)
+ goto disable_clk;
+ }
+
+ ret = dma_async_device_register(ddev);
+ if (ret)
+ goto disable_clk;
+
+ ret = of_dma_controller_register(dev->of_node,
+ milbeaut_hdmac_xlate, mdev);
+ if (ret)
+ goto unregister_dmac;
+
+ platform_set_drvdata(pdev, mdev);
+
+ return 0;
+
+unregister_dmac:
+ dma_async_device_unregister(ddev);
+disable_clk:
+ clk_disable_unprepare(mdev->clk);
+
+ return ret;
+}
+
+static int milbeaut_hdmac_remove(struct platform_device *pdev)
+{
+ struct milbeaut_hdmac_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_hdmac_free_chan_resources(chan);
+ }
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&mdev->ddev);
+ clk_disable_unprepare(mdev->clk);
+
+ return 0;
+}
+
+static const struct of_device_id milbeaut_hdmac_match[] = {
+ { .compatible = "socionext,milbeaut-m10v-hdmac" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, milbeaut_hdmac_match);
+
+static struct platform_driver milbeaut_hdmac_driver = {
+ .probe = milbeaut_hdmac_probe,
+ .remove = milbeaut_hdmac_remove,
+ .driver = {
+ .name = "milbeaut-m10v-hdmac",
+ .of_match_table = milbeaut_hdmac_match,
+ },
+};
+module_platform_driver(milbeaut_hdmac_driver);
+
+MODULE_DESCRIPTION("Milbeaut HDMAC DmaEngine driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1