diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/dma/milbeaut-xdmac.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/drivers/dma/milbeaut-xdmac.c b/drivers/dma/milbeaut-xdmac.c new file mode 100644 index 000000000..748b260bb --- /dev/null +++ b/drivers/dma/milbeaut-xdmac.c @@ -0,0 +1,417 @@ +// 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[]; +}; + +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) + 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) + goto disable_xdmac; + + 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); +disable_xdmac: + disable_xdmac(mdev); + 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"); |