diff options
Diffstat (limited to 'drivers/dma/uniphier-mdmac.c')
| -rw-r--r-- | drivers/dma/uniphier-mdmac.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/dma/uniphier-mdmac.c b/drivers/dma/uniphier-mdmac.c new file mode 100644 index 000000000000..ec65a7430dc4 --- /dev/null +++ b/drivers/dma/uniphier-mdmac.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Copyright (C) 2018 Socionext Inc. +// Author: Masahiro Yamada <yamada.masahiro@socionext.com> + +#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[0]; +}; + +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) { + dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n", + chan_id); + 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; + 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 = 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 <yamada.masahiro@socionext.com>"); +MODULE_DESCRIPTION("UniPhier MIO DMAC driver"); +MODULE_LICENSE("GPL v2"); |