diff options
Diffstat (limited to 'drivers/dma/uniphier-xdmac.c')
| -rw-r--r-- | drivers/dma/uniphier-xdmac.c | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/drivers/dma/uniphier-xdmac.c b/drivers/dma/uniphier-xdmac.c new file mode 100644 index 0000000000..290836b7e1 --- /dev/null +++ b/drivers/dma/uniphier-xdmac.c @@ -0,0 +1,611 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * External DMA controller driver for UniPhier SoCs + * Copyright 2019 Socionext Inc. + * Author: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> + */ + +#include <linux/bitops.h> +#include <linux/bitfield.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +#define XDMAC_CH_WIDTH 0x100 + +#define XDMAC_TFA 0x08 +#define XDMAC_TFA_MCNT_MASK GENMASK(23, 16) +#define XDMAC_TFA_MASK GENMASK(5, 0) +#define XDMAC_SADM 0x10 +#define XDMAC_SADM_STW_MASK GENMASK(25, 24) +#define XDMAC_SADM_SAM BIT(4) +#define XDMAC_SADM_SAM_FIXED XDMAC_SADM_SAM +#define XDMAC_SADM_SAM_INC 0 +#define XDMAC_DADM 0x14 +#define XDMAC_DADM_DTW_MASK XDMAC_SADM_STW_MASK +#define XDMAC_DADM_DAM XDMAC_SADM_SAM +#define XDMAC_DADM_DAM_FIXED XDMAC_SADM_SAM_FIXED +#define XDMAC_DADM_DAM_INC XDMAC_SADM_SAM_INC +#define XDMAC_EXSAD 0x18 +#define XDMAC_EXDAD 0x1c +#define XDMAC_SAD 0x20 +#define XDMAC_DAD 0x24 +#define XDMAC_ITS 0x28 +#define XDMAC_ITS_MASK GENMASK(25, 0) +#define XDMAC_TNUM 0x2c +#define XDMAC_TNUM_MASK GENMASK(15, 0) +#define XDMAC_TSS 0x30 +#define XDMAC_TSS_REQ BIT(0) +#define XDMAC_IEN 0x34 +#define XDMAC_IEN_ERRIEN BIT(1) +#define XDMAC_IEN_ENDIEN BIT(0) +#define XDMAC_STAT 0x40 +#define XDMAC_STAT_TENF BIT(0) +#define XDMAC_IR 0x44 +#define XDMAC_IR_ERRF BIT(1) +#define XDMAC_IR_ENDF BIT(0) +#define XDMAC_ID 0x48 +#define XDMAC_ID_ERRIDF BIT(1) +#define XDMAC_ID_ENDIDF BIT(0) + +#define XDMAC_MAX_CHANS 16 +#define XDMAC_INTERVAL_CLKS 20 +#define XDMAC_MAX_WORDS XDMAC_TNUM_MASK + +/* cut lower bit for maintain alignment of maximum transfer size */ +#define XDMAC_MAX_WORD_SIZE (XDMAC_ITS_MASK & ~GENMASK(3, 0)) + +#define UNIPHIER_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 uniphier_xdmac_desc_node { + dma_addr_t src; + dma_addr_t dst; + u32 burst_size; + u32 nr_burst; +}; + +struct uniphier_xdmac_desc { + struct virt_dma_desc vd; + + unsigned int nr_node; + unsigned int cur_node; + enum dma_transfer_direction dir; + struct uniphier_xdmac_desc_node nodes[]; +}; + +struct uniphier_xdmac_chan { + struct virt_dma_chan vc; + struct uniphier_xdmac_device *xdev; + struct uniphier_xdmac_desc *xd; + void __iomem *reg_ch_base; + struct dma_slave_config sconfig; + int id; + unsigned int req_factor; +}; + +struct uniphier_xdmac_device { + struct dma_device ddev; + void __iomem *reg_base; + int nr_chans; + struct uniphier_xdmac_chan channels[]; +}; + +static struct uniphier_xdmac_chan * +to_uniphier_xdmac_chan(struct virt_dma_chan *vc) +{ + return container_of(vc, struct uniphier_xdmac_chan, vc); +} + +static struct uniphier_xdmac_desc * +to_uniphier_xdmac_desc(struct virt_dma_desc *vd) +{ + return container_of(vd, struct uniphier_xdmac_desc, vd); +} + +/* xc->vc.lock must be held by caller */ +static struct uniphier_xdmac_desc * +uniphier_xdmac_next_desc(struct uniphier_xdmac_chan *xc) +{ + struct virt_dma_desc *vd; + + vd = vchan_next_desc(&xc->vc); + if (!vd) + return NULL; + + list_del(&vd->node); + + return to_uniphier_xdmac_desc(vd); +} + +/* xc->vc.lock must be held by caller */ +static void uniphier_xdmac_chan_start(struct uniphier_xdmac_chan *xc, + struct uniphier_xdmac_desc *xd) +{ + u32 src_mode, src_width; + u32 dst_mode, dst_width; + dma_addr_t src_addr, dst_addr; + u32 val, its, tnum; + enum dma_slave_buswidth buswidth; + + src_addr = xd->nodes[xd->cur_node].src; + dst_addr = xd->nodes[xd->cur_node].dst; + its = xd->nodes[xd->cur_node].burst_size; + tnum = xd->nodes[xd->cur_node].nr_burst; + + /* + * The width of MEM side must be 4 or 8 bytes, that does not + * affect that of DEV side and transfer size. + */ + if (xd->dir == DMA_DEV_TO_MEM) { + src_mode = XDMAC_SADM_SAM_FIXED; + buswidth = xc->sconfig.src_addr_width; + } else { + src_mode = XDMAC_SADM_SAM_INC; + buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES; + } + src_width = FIELD_PREP(XDMAC_SADM_STW_MASK, __ffs(buswidth)); + + if (xd->dir == DMA_MEM_TO_DEV) { + dst_mode = XDMAC_DADM_DAM_FIXED; + buswidth = xc->sconfig.dst_addr_width; + } else { + dst_mode = XDMAC_DADM_DAM_INC; + buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES; + } + dst_width = FIELD_PREP(XDMAC_DADM_DTW_MASK, __ffs(buswidth)); + + /* setup transfer factor */ + val = FIELD_PREP(XDMAC_TFA_MCNT_MASK, XDMAC_INTERVAL_CLKS); + val |= FIELD_PREP(XDMAC_TFA_MASK, xc->req_factor); + writel(val, xc->reg_ch_base + XDMAC_TFA); + + /* setup the channel */ + writel(lower_32_bits(src_addr), xc->reg_ch_base + XDMAC_SAD); + writel(upper_32_bits(src_addr), xc->reg_ch_base + XDMAC_EXSAD); + + writel(lower_32_bits(dst_addr), xc->reg_ch_base + XDMAC_DAD); + writel(upper_32_bits(dst_addr), xc->reg_ch_base + XDMAC_EXDAD); + + src_mode |= src_width; + dst_mode |= dst_width; + writel(src_mode, xc->reg_ch_base + XDMAC_SADM); + writel(dst_mode, xc->reg_ch_base + XDMAC_DADM); + + writel(its, xc->reg_ch_base + XDMAC_ITS); + writel(tnum, xc->reg_ch_base + XDMAC_TNUM); + + /* enable interrupt */ + writel(XDMAC_IEN_ENDIEN | XDMAC_IEN_ERRIEN, + xc->reg_ch_base + XDMAC_IEN); + + /* start XDMAC */ + val = readl(xc->reg_ch_base + XDMAC_TSS); + val |= XDMAC_TSS_REQ; + writel(val, xc->reg_ch_base + XDMAC_TSS); +} + +/* xc->vc.lock must be held by caller */ +static int uniphier_xdmac_chan_stop(struct uniphier_xdmac_chan *xc) +{ + u32 val; + + /* disable interrupt */ + val = readl(xc->reg_ch_base + XDMAC_IEN); + val &= ~(XDMAC_IEN_ENDIEN | XDMAC_IEN_ERRIEN); + writel(val, xc->reg_ch_base + XDMAC_IEN); + + /* stop XDMAC */ + val = readl(xc->reg_ch_base + XDMAC_TSS); + val &= ~XDMAC_TSS_REQ; + writel(0, xc->reg_ch_base + XDMAC_TSS); + + /* wait until transfer is stopped */ + return readl_poll_timeout_atomic(xc->reg_ch_base + XDMAC_STAT, val, + !(val & XDMAC_STAT_TENF), 100, 1000); +} + +/* xc->vc.lock must be held by caller */ +static void uniphier_xdmac_start(struct uniphier_xdmac_chan *xc) +{ + struct uniphier_xdmac_desc *xd; + + xd = uniphier_xdmac_next_desc(xc); + if (xd) + uniphier_xdmac_chan_start(xc, xd); + + /* set desc to chan regardless of xd is null */ + xc->xd = xd; +} + +static void uniphier_xdmac_chan_irq(struct uniphier_xdmac_chan *xc) +{ + u32 stat; + int ret; + + spin_lock(&xc->vc.lock); + + stat = readl(xc->reg_ch_base + XDMAC_ID); + + if (stat & XDMAC_ID_ERRIDF) { + ret = uniphier_xdmac_chan_stop(xc); + if (ret) + dev_err(xc->xdev->ddev.dev, + "DMA transfer error with aborting issue\n"); + else + dev_err(xc->xdev->ddev.dev, + "DMA transfer error\n"); + + } else if ((stat & XDMAC_ID_ENDIDF) && xc->xd) { + xc->xd->cur_node++; + if (xc->xd->cur_node >= xc->xd->nr_node) { + vchan_cookie_complete(&xc->xd->vd); + uniphier_xdmac_start(xc); + } else { + uniphier_xdmac_chan_start(xc, xc->xd); + } + } + + /* write bits to clear */ + writel(stat, xc->reg_ch_base + XDMAC_IR); + + spin_unlock(&xc->vc.lock); +} + +static irqreturn_t uniphier_xdmac_irq_handler(int irq, void *dev_id) +{ + struct uniphier_xdmac_device *xdev = dev_id; + int i; + + for (i = 0; i < xdev->nr_chans; i++) + uniphier_xdmac_chan_irq(&xdev->channels[i]); + + return IRQ_HANDLED; +} + +static void uniphier_xdmac_free_chan_resources(struct dma_chan *chan) +{ + vchan_free_chan_resources(to_virt_chan(chan)); +} + +static struct dma_async_tx_descriptor * +uniphier_xdmac_prep_dma_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 uniphier_xdmac_desc *xd; + unsigned int nr; + size_t burst_size, tlen; + int i; + + if (len > XDMAC_MAX_WORD_SIZE * XDMAC_MAX_WORDS) + return NULL; + + nr = 1 + len / XDMAC_MAX_WORD_SIZE; + + xd = kzalloc(struct_size(xd, nodes, nr), GFP_NOWAIT); + if (!xd) + return NULL; + + for (i = 0; i < nr; i++) { + burst_size = min_t(size_t, len, XDMAC_MAX_WORD_SIZE); + xd->nodes[i].src = src; + xd->nodes[i].dst = dst; + xd->nodes[i].burst_size = burst_size; + xd->nodes[i].nr_burst = len / burst_size; + tlen = rounddown(len, burst_size); + src += tlen; + dst += tlen; + len -= tlen; + } + + xd->dir = DMA_MEM_TO_MEM; + xd->nr_node = nr; + xd->cur_node = 0; + + return vchan_tx_prep(vc, &xd->vd, flags); +} + +static struct dma_async_tx_descriptor * +uniphier_xdmac_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_xdmac_chan *xc = to_uniphier_xdmac_chan(vc); + struct uniphier_xdmac_desc *xd; + struct scatterlist *sg; + enum dma_slave_buswidth buswidth; + u32 maxburst; + int i; + + if (!is_slave_direction(direction)) + return NULL; + + if (direction == DMA_DEV_TO_MEM) { + buswidth = xc->sconfig.src_addr_width; + maxburst = xc->sconfig.src_maxburst; + } else { + buswidth = xc->sconfig.dst_addr_width; + maxburst = xc->sconfig.dst_maxburst; + } + + if (!maxburst) + maxburst = 1; + if (maxburst > xc->xdev->ddev.max_burst) { + dev_err(xc->xdev->ddev.dev, + "Exceed maximum number of burst words\n"); + return NULL; + } + + xd = kzalloc(struct_size(xd, nodes, sg_len), GFP_NOWAIT); + if (!xd) + return NULL; + + for_each_sg(sgl, sg, sg_len, i) { + xd->nodes[i].src = (direction == DMA_DEV_TO_MEM) + ? xc->sconfig.src_addr : sg_dma_address(sg); + xd->nodes[i].dst = (direction == DMA_MEM_TO_DEV) + ? xc->sconfig.dst_addr : sg_dma_address(sg); + xd->nodes[i].burst_size = maxburst * buswidth; + xd->nodes[i].nr_burst = + sg_dma_len(sg) / xd->nodes[i].burst_size; + + /* + * Currently transfer that size doesn't align the unit size + * (the number of burst words * bus-width) is not allowed, + * because the driver does not support the way to transfer + * residue size. As a matter of fact, in order to transfer + * arbitrary size, 'src_maxburst' or 'dst_maxburst' of + * dma_slave_config must be 1. + */ + if (sg_dma_len(sg) % xd->nodes[i].burst_size) { + dev_err(xc->xdev->ddev.dev, + "Unaligned transfer size: %d", sg_dma_len(sg)); + kfree(xd); + return NULL; + } + + if (xd->nodes[i].nr_burst > XDMAC_MAX_WORDS) { + dev_err(xc->xdev->ddev.dev, + "Exceed maximum transfer size"); + kfree(xd); + return NULL; + } + } + + xd->dir = direction; + xd->nr_node = sg_len; + xd->cur_node = 0; + + return vchan_tx_prep(vc, &xd->vd, flags); +} + +static int uniphier_xdmac_slave_config(struct dma_chan *chan, + struct dma_slave_config *config) +{ + struct virt_dma_chan *vc = to_virt_chan(chan); + struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc); + + memcpy(&xc->sconfig, config, sizeof(*config)); + + return 0; +} + +static int uniphier_xdmac_terminate_all(struct dma_chan *chan) +{ + struct virt_dma_chan *vc = to_virt_chan(chan); + struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc); + unsigned long flags; + int ret = 0; + LIST_HEAD(head); + + spin_lock_irqsave(&vc->lock, flags); + + if (xc->xd) { + vchan_terminate_vdesc(&xc->xd->vd); + xc->xd = NULL; + ret = uniphier_xdmac_chan_stop(xc); + } + + vchan_get_all_descriptors(vc, &head); + + spin_unlock_irqrestore(&vc->lock, flags); + + vchan_dma_desc_free_list(vc, &head); + + return ret; +} + +static void uniphier_xdmac_synchronize(struct dma_chan *chan) +{ + vchan_synchronize(to_virt_chan(chan)); +} + +static void uniphier_xdmac_issue_pending(struct dma_chan *chan) +{ + struct virt_dma_chan *vc = to_virt_chan(chan); + struct uniphier_xdmac_chan *xc = to_uniphier_xdmac_chan(vc); + unsigned long flags; + + spin_lock_irqsave(&vc->lock, flags); + + if (vchan_issue_pending(vc) && !xc->xd) + uniphier_xdmac_start(xc); + + spin_unlock_irqrestore(&vc->lock, flags); +} + +static void uniphier_xdmac_desc_free(struct virt_dma_desc *vd) +{ + kfree(to_uniphier_xdmac_desc(vd)); +} + +static void uniphier_xdmac_chan_init(struct uniphier_xdmac_device *xdev, + int ch) +{ + struct uniphier_xdmac_chan *xc = &xdev->channels[ch]; + + xc->xdev = xdev; + xc->reg_ch_base = xdev->reg_base + XDMAC_CH_WIDTH * ch; + xc->vc.desc_free = uniphier_xdmac_desc_free; + + vchan_init(&xc->vc, &xdev->ddev); +} + +static struct dma_chan *of_dma_uniphier_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct uniphier_xdmac_device *xdev = ofdma->of_dma_data; + int chan_id = dma_spec->args[0]; + + if (chan_id >= xdev->nr_chans) + return NULL; + + xdev->channels[chan_id].id = chan_id; + xdev->channels[chan_id].req_factor = dma_spec->args[1]; + + return dma_get_slave_channel(&xdev->channels[chan_id].vc.chan); +} + +static int uniphier_xdmac_probe(struct platform_device *pdev) +{ + struct uniphier_xdmac_device *xdev; + struct device *dev = &pdev->dev; + struct dma_device *ddev; + int irq; + int nr_chans; + int i, ret; + + if (of_property_read_u32(dev->of_node, "dma-channels", &nr_chans)) + return -EINVAL; + if (nr_chans > XDMAC_MAX_CHANS) + nr_chans = XDMAC_MAX_CHANS; + + xdev = devm_kzalloc(dev, struct_size(xdev, channels, nr_chans), + GFP_KERNEL); + if (!xdev) + return -ENOMEM; + + xdev->nr_chans = nr_chans; + xdev->reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(xdev->reg_base)) + return PTR_ERR(xdev->reg_base); + + ddev = &xdev->ddev; + ddev->dev = dev; + dma_cap_zero(ddev->cap_mask); + dma_cap_set(DMA_MEMCPY, ddev->cap_mask); + dma_cap_set(DMA_SLAVE, ddev->cap_mask); + ddev->src_addr_widths = UNIPHIER_XDMAC_BUSWIDTHS; + ddev->dst_addr_widths = UNIPHIER_XDMAC_BUSWIDTHS; + ddev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | + BIT(DMA_MEM_TO_MEM); + ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + ddev->max_burst = XDMAC_MAX_WORDS; + ddev->device_free_chan_resources = uniphier_xdmac_free_chan_resources; + ddev->device_prep_dma_memcpy = uniphier_xdmac_prep_dma_memcpy; + ddev->device_prep_slave_sg = uniphier_xdmac_prep_slave_sg; + ddev->device_config = uniphier_xdmac_slave_config; + ddev->device_terminate_all = uniphier_xdmac_terminate_all; + ddev->device_synchronize = uniphier_xdmac_synchronize; + ddev->device_tx_status = dma_cookie_status; + ddev->device_issue_pending = uniphier_xdmac_issue_pending; + INIT_LIST_HEAD(&ddev->channels); + + for (i = 0; i < nr_chans; i++) + uniphier_xdmac_chan_init(xdev, i); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, uniphier_xdmac_irq_handler, + IRQF_SHARED, "xdmac", xdev); + if (ret) { + dev_err(dev, "Failed to request IRQ\n"); + return ret; + } + + ret = dma_async_device_register(ddev); + if (ret) { + dev_err(dev, "Failed to register XDMA device\n"); + return ret; + } + + ret = of_dma_controller_register(dev->of_node, + of_dma_uniphier_xlate, xdev); + if (ret) { + dev_err(dev, "Failed to register XDMA controller\n"); + goto out_unregister_dmac; + } + + platform_set_drvdata(pdev, xdev); + + dev_info(&pdev->dev, "UniPhier XDMAC driver (%d channels)\n", + nr_chans); + + return 0; + +out_unregister_dmac: + dma_async_device_unregister(ddev); + + return ret; +} + +static int uniphier_xdmac_remove(struct platform_device *pdev) +{ + struct uniphier_xdmac_device *xdev = platform_get_drvdata(pdev); + struct dma_device *ddev = &xdev->ddev; + 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, &ddev->channels, device_node) { + ret = dmaengine_terminate_sync(chan); + if (ret) + return ret; + uniphier_xdmac_free_chan_resources(chan); + } + + of_dma_controller_free(pdev->dev.of_node); + dma_async_device_unregister(ddev); + + return 0; +} + +static const struct of_device_id uniphier_xdmac_match[] = { + { .compatible = "socionext,uniphier-xdmac" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, uniphier_xdmac_match); + +static struct platform_driver uniphier_xdmac_driver = { + .probe = uniphier_xdmac_probe, + .remove = uniphier_xdmac_remove, + .driver = { + .name = "uniphier-xdmac", + .of_match_table = uniphier_xdmac_match, + }, +}; +module_platform_driver(uniphier_xdmac_driver); + +MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>"); +MODULE_DESCRIPTION("UniPhier external DMA controller driver"); +MODULE_LICENSE("GPL v2"); |