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- // SPDX-License-Identifier: GPL-2.0
- //
- // Copyright (C) 2018 Socionext Inc.
- // Author: Masahiro Yamada <[email protected]>
- #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 "virt-dma.h"
- /* registers common for all channels */
- #define UNIPHIER_MDMAC_CMD 0x000 /* issue DMA start/abort */
- #define UNIPHIER_MDMAC_CMD_ABORT BIT(31) /* 1: abort, 0: start */
- /* per-channel registers */
- #define UNIPHIER_MDMAC_CH_OFFSET 0x100
- #define UNIPHIER_MDMAC_CH_STRIDE 0x040
- #define UNIPHIER_MDMAC_CH_IRQ_STAT 0x010 /* current hw status (RO) */
- #define UNIPHIER_MDMAC_CH_IRQ_REQ 0x014 /* latched STAT (WOC) */
- #define UNIPHIER_MDMAC_CH_IRQ_EN 0x018 /* IRQ enable mask */
- #define UNIPHIER_MDMAC_CH_IRQ_DET 0x01c /* REQ & EN (RO) */
- #define UNIPHIER_MDMAC_CH_IRQ__ABORT BIT(13)
- #define UNIPHIER_MDMAC_CH_IRQ__DONE BIT(1)
- #define UNIPHIER_MDMAC_CH_SRC_MODE 0x020 /* mode of source */
- #define UNIPHIER_MDMAC_CH_DEST_MODE 0x024 /* mode of destination */
- #define UNIPHIER_MDMAC_CH_MODE__ADDR_INC (0 << 4)
- #define UNIPHIER_MDMAC_CH_MODE__ADDR_DEC (1 << 4)
- #define UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED (2 << 4)
- #define UNIPHIER_MDMAC_CH_SRC_ADDR 0x028 /* source address */
- #define UNIPHIER_MDMAC_CH_DEST_ADDR 0x02c /* destination address */
- #define UNIPHIER_MDMAC_CH_SIZE 0x030 /* transfer bytes */
- #define UNIPHIER_MDMAC_SLAVE_BUSWIDTHS \
- (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
- BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
- BIT(DMA_SLAVE_BUSWIDTH_3_BYTES) | \
- BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
- struct uniphier_mdmac_desc {
- struct virt_dma_desc vd;
- struct scatterlist *sgl;
- unsigned int sg_len;
- unsigned int sg_cur;
- enum dma_transfer_direction dir;
- };
- struct uniphier_mdmac_chan {
- struct virt_dma_chan vc;
- struct uniphier_mdmac_device *mdev;
- struct uniphier_mdmac_desc *md;
- void __iomem *reg_ch_base;
- unsigned int chan_id;
- };
- struct uniphier_mdmac_device {
- struct dma_device ddev;
- struct clk *clk;
- void __iomem *reg_base;
- struct uniphier_mdmac_chan channels[];
- };
- static struct uniphier_mdmac_chan *
- to_uniphier_mdmac_chan(struct virt_dma_chan *vc)
- {
- return container_of(vc, struct uniphier_mdmac_chan, vc);
- }
- static struct uniphier_mdmac_desc *
- to_uniphier_mdmac_desc(struct virt_dma_desc *vd)
- {
- return container_of(vd, struct uniphier_mdmac_desc, vd);
- }
- /* mc->vc.lock must be held by caller */
- static struct uniphier_mdmac_desc *
- uniphier_mdmac_next_desc(struct uniphier_mdmac_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_uniphier_mdmac_desc(vd);
- return mc->md;
- }
- /* mc->vc.lock must be held by caller */
- static void uniphier_mdmac_handle(struct uniphier_mdmac_chan *mc,
- struct uniphier_mdmac_desc *md)
- {
- struct uniphier_mdmac_device *mdev = mc->mdev;
- struct scatterlist *sg;
- u32 irq_flag = UNIPHIER_MDMAC_CH_IRQ__DONE;
- u32 src_mode, src_addr, dest_mode, dest_addr, chunk_size;
- sg = &md->sgl[md->sg_cur];
- if (md->dir == DMA_MEM_TO_DEV) {
- src_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_INC;
- src_addr = sg_dma_address(sg);
- dest_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED;
- dest_addr = 0;
- } else {
- src_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_FIXED;
- src_addr = 0;
- dest_mode = UNIPHIER_MDMAC_CH_MODE__ADDR_INC;
- dest_addr = sg_dma_address(sg);
- }
- chunk_size = sg_dma_len(sg);
- writel(src_mode, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SRC_MODE);
- writel(dest_mode, mc->reg_ch_base + UNIPHIER_MDMAC_CH_DEST_MODE);
- writel(src_addr, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SRC_ADDR);
- writel(dest_addr, mc->reg_ch_base + UNIPHIER_MDMAC_CH_DEST_ADDR);
- writel(chunk_size, mc->reg_ch_base + UNIPHIER_MDMAC_CH_SIZE);
- /* write 1 to clear */
- writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
- writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_EN);
- writel(BIT(mc->chan_id), mdev->reg_base + UNIPHIER_MDMAC_CMD);
- }
- /* mc->vc.lock must be held by caller */
- static void uniphier_mdmac_start(struct uniphier_mdmac_chan *mc)
- {
- struct uniphier_mdmac_desc *md;
- md = uniphier_mdmac_next_desc(mc);
- if (md)
- uniphier_mdmac_handle(mc, md);
- }
- /* mc->vc.lock must be held by caller */
- static int uniphier_mdmac_abort(struct uniphier_mdmac_chan *mc)
- {
- struct uniphier_mdmac_device *mdev = mc->mdev;
- u32 irq_flag = UNIPHIER_MDMAC_CH_IRQ__ABORT;
- u32 val;
- /* write 1 to clear */
- writel(irq_flag, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
- writel(UNIPHIER_MDMAC_CMD_ABORT | BIT(mc->chan_id),
- mdev->reg_base + UNIPHIER_MDMAC_CMD);
- /*
- * Abort should be accepted soon. We poll the bit here instead of
- * waiting for the interrupt.
- */
- return readl_poll_timeout(mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ,
- val, val & irq_flag, 0, 20);
- }
- static irqreturn_t uniphier_mdmac_interrupt(int irq, void *dev_id)
- {
- struct uniphier_mdmac_chan *mc = dev_id;
- struct uniphier_mdmac_desc *md;
- irqreturn_t ret = IRQ_HANDLED;
- u32 irq_stat;
- spin_lock(&mc->vc.lock);
- irq_stat = readl(mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_DET);
- /*
- * Some channels share a single interrupt line. If the IRQ status is 0,
- * this is probably triggered by a different channel.
- */
- if (!irq_stat) {
- ret = IRQ_NONE;
- goto out;
- }
- /* write 1 to clear */
- writel(irq_stat, mc->reg_ch_base + UNIPHIER_MDMAC_CH_IRQ_REQ);
- /*
- * UNIPHIER_MDMAC_CH_IRQ__DONE interrupt is asserted even when the DMA
- * is aborted. To distinguish the normal completion and the abort,
- * check mc->md. If it is NULL, we are aborting.
- */
- md = mc->md;
- if (!md)
- goto out;
- md->sg_cur++;
- if (md->sg_cur >= md->sg_len) {
- vchan_cookie_complete(&md->vd);
- md = uniphier_mdmac_next_desc(mc);
- if (!md)
- goto out;
- }
- uniphier_mdmac_handle(mc, md);
- out:
- spin_unlock(&mc->vc.lock);
- return ret;
- }
- static void uniphier_mdmac_free_chan_resources(struct dma_chan *chan)
- {
- vchan_free_chan_resources(to_virt_chan(chan));
- }
- static struct dma_async_tx_descriptor *
- uniphier_mdmac_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 uniphier_mdmac_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 uniphier_mdmac_terminate_all(struct dma_chan *chan)
- {
- struct virt_dma_chan *vc = to_virt_chan(chan);
- struct uniphier_mdmac_chan *mc = to_uniphier_mdmac_chan(vc);
- unsigned long flags;
- int ret = 0;
- LIST_HEAD(head);
- spin_lock_irqsave(&vc->lock, flags);
- if (mc->md) {
- vchan_terminate_vdesc(&mc->md->vd);
- mc->md = NULL;
- ret = uniphier_mdmac_abort(mc);
- }
- vchan_get_all_descriptors(vc, &head);
- spin_unlock_irqrestore(&vc->lock, flags);
- vchan_dma_desc_free_list(vc, &head);
- return ret;
- }
- static void uniphier_mdmac_synchronize(struct dma_chan *chan)
- {
- vchan_synchronize(to_virt_chan(chan));
- }
- static enum dma_status uniphier_mdmac_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 uniphier_mdmac_chan *mc;
- struct uniphier_mdmac_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_uniphier_mdmac_chan(vc);
- if (mc->md && mc->md->vd.tx.cookie == cookie) {
- /* residue from the on-flight chunk */
- txstate->residue = readl(mc->reg_ch_base +
- UNIPHIER_MDMAC_CH_SIZE);
- md = mc->md;
- }
- if (!md) {
- vd = vchan_find_desc(vc, cookie);
- if (vd)
- md = to_uniphier_mdmac_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 uniphier_mdmac_issue_pending(struct dma_chan *chan)
- {
- struct virt_dma_chan *vc = to_virt_chan(chan);
- struct uniphier_mdmac_chan *mc = to_uniphier_mdmac_chan(vc);
- unsigned long flags;
- spin_lock_irqsave(&vc->lock, flags);
- if (vchan_issue_pending(vc) && !mc->md)
- uniphier_mdmac_start(mc);
- spin_unlock_irqrestore(&vc->lock, flags);
- }
- static void uniphier_mdmac_desc_free(struct virt_dma_desc *vd)
- {
- kfree(to_uniphier_mdmac_desc(vd));
- }
- static int uniphier_mdmac_chan_init(struct platform_device *pdev,
- struct uniphier_mdmac_device *mdev,
- int chan_id)
- {
- struct device *dev = &pdev->dev;
- struct uniphier_mdmac_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, "uniphier-mio-dmac-ch%d",
- chan_id);
- if (!irq_name)
- return -ENOMEM;
- ret = devm_request_irq(dev, irq, uniphier_mdmac_interrupt,
- IRQF_SHARED, irq_name, mc);
- if (ret)
- return ret;
- mc->mdev = mdev;
- mc->reg_ch_base = mdev->reg_base + UNIPHIER_MDMAC_CH_OFFSET +
- UNIPHIER_MDMAC_CH_STRIDE * chan_id;
- mc->chan_id = chan_id;
- mc->vc.desc_free = uniphier_mdmac_desc_free;
- vchan_init(&mc->vc, &mdev->ddev);
- return 0;
- }
- static int uniphier_mdmac_probe(struct platform_device *pdev)
- {
- struct device *dev = &pdev->dev;
- struct uniphier_mdmac_device *mdev;
- struct dma_device *ddev;
- 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;
- mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
- 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 = UNIPHIER_MDMAC_SLAVE_BUSWIDTHS;
- ddev->dst_addr_widths = UNIPHIER_MDMAC_SLAVE_BUSWIDTHS;
- ddev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
- ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
- ddev->device_free_chan_resources = uniphier_mdmac_free_chan_resources;
- ddev->device_prep_slave_sg = uniphier_mdmac_prep_slave_sg;
- ddev->device_terminate_all = uniphier_mdmac_terminate_all;
- ddev->device_synchronize = uniphier_mdmac_synchronize;
- ddev->device_tx_status = uniphier_mdmac_tx_status;
- ddev->device_issue_pending = uniphier_mdmac_issue_pending;
- INIT_LIST_HEAD(&ddev->channels);
- for (i = 0; i < nr_chans; i++) {
- ret = uniphier_mdmac_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, of_dma_xlate_by_chan_id,
- ddev);
- 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 uniphier_mdmac_remove(struct platform_device *pdev)
- {
- struct uniphier_mdmac_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;
- uniphier_mdmac_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 uniphier_mdmac_match[] = {
- { .compatible = "socionext,uniphier-mio-dmac" },
- { /* sentinel */ }
- };
- MODULE_DEVICE_TABLE(of, uniphier_mdmac_match);
- static struct platform_driver uniphier_mdmac_driver = {
- .probe = uniphier_mdmac_probe,
- .remove = uniphier_mdmac_remove,
- .driver = {
- .name = "uniphier-mio-dmac",
- .of_match_table = uniphier_mdmac_match,
- },
- };
- module_platform_driver(uniphier_mdmac_driver);
- MODULE_AUTHOR("Masahiro Yamada <[email protected]>");
- MODULE_DESCRIPTION("UniPhier MIO DMAC driver");
- MODULE_LICENSE("GPL v2");
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