// SPDX-License-Identifier: GPL-2.0-only /* * Core driver for the Intel integrated DMA 64-bit * * Copyright (C) 2015 Intel Corporation * Author: Andy Shevchenko */ #include #include #include #include #include #include #include #include #include #include #include "idma64.h" /* For now we support only two channels */ #define IDMA64_NR_CHAN 2 /* ---------------------------------------------------------------------- */ static struct device *chan2dev(struct dma_chan *chan) { return &chan->dev->device; } /* ---------------------------------------------------------------------- */ static void idma64_off(struct idma64 *idma64) { unsigned short count = 100; dma_writel(idma64, CFG, 0); channel_clear_bit(idma64, MASK(XFER), idma64->all_chan_mask); channel_clear_bit(idma64, MASK(BLOCK), idma64->all_chan_mask); channel_clear_bit(idma64, MASK(SRC_TRAN), idma64->all_chan_mask); channel_clear_bit(idma64, MASK(DST_TRAN), idma64->all_chan_mask); channel_clear_bit(idma64, MASK(ERROR), idma64->all_chan_mask); do { cpu_relax(); } while (dma_readl(idma64, CFG) & IDMA64_CFG_DMA_EN && --count); } static void idma64_on(struct idma64 *idma64) { dma_writel(idma64, CFG, IDMA64_CFG_DMA_EN); } /* ---------------------------------------------------------------------- */ static void idma64_chan_init(struct idma64 *idma64, struct idma64_chan *idma64c) { u32 cfghi = IDMA64C_CFGH_SRC_PER(1) | IDMA64C_CFGH_DST_PER(0); u32 cfglo = 0; /* Set default burst alignment */ cfglo |= IDMA64C_CFGL_DST_BURST_ALIGN | IDMA64C_CFGL_SRC_BURST_ALIGN; channel_writel(idma64c, CFG_LO, cfglo); channel_writel(idma64c, CFG_HI, cfghi); /* Enable interrupts */ channel_set_bit(idma64, MASK(XFER), idma64c->mask); channel_set_bit(idma64, MASK(ERROR), idma64c->mask); /* * Enforce the controller to be turned on. * * The iDMA is turned off in ->probe() and looses context during system * suspend / resume cycle. That's why we have to enable it each time we * use it. */ idma64_on(idma64); } static void idma64_chan_stop(struct idma64 *idma64, struct idma64_chan *idma64c) { channel_clear_bit(idma64, CH_EN, idma64c->mask); } static void idma64_chan_start(struct idma64 *idma64, struct idma64_chan *idma64c) { struct idma64_desc *desc = idma64c->desc; struct idma64_hw_desc *hw = &desc->hw[0]; channel_writeq(idma64c, SAR, 0); channel_writeq(idma64c, DAR, 0); channel_writel(idma64c, CTL_HI, IDMA64C_CTLH_BLOCK_TS(~0UL)); channel_writel(idma64c, CTL_LO, IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN); channel_writeq(idma64c, LLP, hw->llp); channel_set_bit(idma64, CH_EN, idma64c->mask); } static void idma64_stop_transfer(struct idma64_chan *idma64c) { struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device); idma64_chan_stop(idma64, idma64c); } static void idma64_start_transfer(struct idma64_chan *idma64c) { struct idma64 *idma64 = to_idma64(idma64c->vchan.chan.device); struct virt_dma_desc *vdesc; /* Get the next descriptor */ vdesc = vchan_next_desc(&idma64c->vchan); if (!vdesc) { idma64c->desc = NULL; return; } list_del(&vdesc->node); idma64c->desc = to_idma64_desc(vdesc); /* Configure the channel */ idma64_chan_init(idma64, idma64c); /* Start the channel with a new descriptor */ idma64_chan_start(idma64, idma64c); } /* ---------------------------------------------------------------------- */ static void idma64_chan_irq(struct idma64 *idma64, unsigned short c, u32 status_err, u32 status_xfer) { struct idma64_chan *idma64c = &idma64->chan[c]; struct dma_chan_percpu *stat; struct idma64_desc *desc; stat = this_cpu_ptr(idma64c->vchan.chan.local); spin_lock(&idma64c->vchan.lock); desc = idma64c->desc; if (desc) { if (status_err & (1 << c)) { dma_writel(idma64, CLEAR(ERROR), idma64c->mask); desc->status = DMA_ERROR; } else if (status_xfer & (1 << c)) { dma_writel(idma64, CLEAR(XFER), idma64c->mask); desc->status = DMA_COMPLETE; vchan_cookie_complete(&desc->vdesc); stat->bytes_transferred += desc->length; idma64_start_transfer(idma64c); } /* idma64_start_transfer() updates idma64c->desc */ if (idma64c->desc == NULL || desc->status == DMA_ERROR) idma64_stop_transfer(idma64c); } spin_unlock(&idma64c->vchan.lock); } static irqreturn_t idma64_irq(int irq, void *dev) { struct idma64 *idma64 = dev; u32 status = dma_readl(idma64, STATUS_INT); u32 status_xfer; u32 status_err; unsigned short i; /* Since IRQ may be shared, check if DMA controller is powered on */ if (status == GENMASK(31, 0)) return IRQ_NONE; dev_vdbg(idma64->dma.dev, "%s: status=%#x\n", __func__, status); /* Check if we have any interrupt from the DMA controller */ if (!status) return IRQ_NONE; status_xfer = dma_readl(idma64, RAW(XFER)); status_err = dma_readl(idma64, RAW(ERROR)); for (i = 0; i < idma64->dma.chancnt; i++) idma64_chan_irq(idma64, i, status_err, status_xfer); return IRQ_HANDLED; } /* ---------------------------------------------------------------------- */ static struct idma64_desc *idma64_alloc_desc(unsigned int ndesc) { struct idma64_desc *desc; desc = kzalloc(sizeof(*desc), GFP_NOWAIT); if (!desc) return NULL; desc->hw = kcalloc(ndesc, sizeof(*desc->hw), GFP_NOWAIT); if (!desc->hw) { kfree(desc); return NULL; } return desc; } static void idma64_desc_free(struct idma64_chan *idma64c, struct idma64_desc *desc) { struct idma64_hw_desc *hw; if (desc->ndesc) { unsigned int i = desc->ndesc; do { hw = &desc->hw[--i]; dma_pool_free(idma64c->pool, hw->lli, hw->llp); } while (i); } kfree(desc->hw); kfree(desc); } static void idma64_vdesc_free(struct virt_dma_desc *vdesc) { struct idma64_chan *idma64c = to_idma64_chan(vdesc->tx.chan); idma64_desc_free(idma64c, to_idma64_desc(vdesc)); } static void idma64_hw_desc_fill(struct idma64_hw_desc *hw, struct dma_slave_config *config, enum dma_transfer_direction direction, u64 llp) { struct idma64_lli *lli = hw->lli; u64 sar, dar; u32 ctlhi = IDMA64C_CTLH_BLOCK_TS(hw->len); u32 ctllo = IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN; u32 src_width, dst_width; if (direction == DMA_MEM_TO_DEV) { sar = hw->phys; dar = config->dst_addr; ctllo |= IDMA64C_CTLL_DST_FIX | IDMA64C_CTLL_SRC_INC | IDMA64C_CTLL_FC_M2P; src_width = __ffs(sar | hw->len | 4); dst_width = __ffs(config->dst_addr_width); } else { /* DMA_DEV_TO_MEM */ sar = config->src_addr; dar = hw->phys; ctllo |= IDMA64C_CTLL_DST_INC | IDMA64C_CTLL_SRC_FIX | IDMA64C_CTLL_FC_P2M; src_width = __ffs(config->src_addr_width); dst_width = __ffs(dar | hw->len | 4); } lli->sar = sar; lli->dar = dar; lli->ctlhi = ctlhi; lli->ctllo = ctllo | IDMA64C_CTLL_SRC_MSIZE(config->src_maxburst) | IDMA64C_CTLL_DST_MSIZE(config->dst_maxburst) | IDMA64C_CTLL_DST_WIDTH(dst_width) | IDMA64C_CTLL_SRC_WIDTH(src_width); lli->llp = llp; } static void idma64_desc_fill(struct idma64_chan *idma64c, struct idma64_desc *desc) { struct dma_slave_config *config = &idma64c->config; unsigned int i = desc->ndesc; struct idma64_hw_desc *hw = &desc->hw[i - 1]; struct idma64_lli *lli = hw->lli; u64 llp = 0; /* Fill the hardware descriptors and link them to a list */ do { hw = &desc->hw[--i]; idma64_hw_desc_fill(hw, config, desc->direction, llp); llp = hw->llp; desc->length += hw->len; } while (i); /* Trigger an interrupt after the last block is transferred */ lli->ctllo |= IDMA64C_CTLL_INT_EN; /* Disable LLP transfer in the last block */ lli->ctllo &= ~(IDMA64C_CTLL_LLP_S_EN | IDMA64C_CTLL_LLP_D_EN); } static struct dma_async_tx_descriptor *idma64_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 idma64_chan *idma64c = to_idma64_chan(chan); struct idma64_desc *desc; struct scatterlist *sg; unsigned int i; desc = idma64_alloc_desc(sg_len); if (!desc) return NULL; for_each_sg(sgl, sg, sg_len, i) { struct idma64_hw_desc *hw = &desc->hw[i]; /* Allocate DMA capable memory for hardware descriptor */ hw->lli = dma_pool_alloc(idma64c->pool, GFP_NOWAIT, &hw->llp); if (!hw->lli) { desc->ndesc = i; idma64_desc_free(idma64c, desc); return NULL; } hw->phys = sg_dma_address(sg); hw->len = sg_dma_len(sg); } desc->ndesc = sg_len; desc->direction = direction; desc->status = DMA_IN_PROGRESS; idma64_desc_fill(idma64c, desc); return vchan_tx_prep(&idma64c->vchan, &desc->vdesc, flags); } static void idma64_issue_pending(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); unsigned long flags; spin_lock_irqsave(&idma64c->vchan.lock, flags); if (vchan_issue_pending(&idma64c->vchan) && !idma64c->desc) idma64_start_transfer(idma64c); spin_unlock_irqrestore(&idma64c->vchan.lock, flags); } static size_t idma64_active_desc_size(struct idma64_chan *idma64c) { struct idma64_desc *desc = idma64c->desc; struct idma64_hw_desc *hw; size_t bytes = desc->length; u64 llp = channel_readq(idma64c, LLP); u32 ctlhi = channel_readl(idma64c, CTL_HI); unsigned int i = 0; do { hw = &desc->hw[i]; if (hw->llp == llp) break; bytes -= hw->len; } while (++i < desc->ndesc); if (!i) return bytes; /* The current chunk is not fully transferred yet */ bytes += desc->hw[--i].len; return bytes - IDMA64C_CTLH_BLOCK_TS(ctlhi); } static enum dma_status idma64_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *state) { struct idma64_chan *idma64c = to_idma64_chan(chan); struct virt_dma_desc *vdesc; enum dma_status status; size_t bytes; unsigned long flags; status = dma_cookie_status(chan, cookie, state); if (status == DMA_COMPLETE) return status; spin_lock_irqsave(&idma64c->vchan.lock, flags); vdesc = vchan_find_desc(&idma64c->vchan, cookie); if (idma64c->desc && cookie == idma64c->desc->vdesc.tx.cookie) { bytes = idma64_active_desc_size(idma64c); dma_set_residue(state, bytes); status = idma64c->desc->status; } else if (vdesc) { bytes = to_idma64_desc(vdesc)->length; dma_set_residue(state, bytes); } spin_unlock_irqrestore(&idma64c->vchan.lock, flags); return status; } static void convert_burst(u32 *maxburst) { if (*maxburst) *maxburst = __fls(*maxburst); else *maxburst = 0; } static int idma64_slave_config(struct dma_chan *chan, struct dma_slave_config *config) { struct idma64_chan *idma64c = to_idma64_chan(chan); memcpy(&idma64c->config, config, sizeof(idma64c->config)); convert_burst(&idma64c->config.src_maxburst); convert_burst(&idma64c->config.dst_maxburst); return 0; } static void idma64_chan_deactivate(struct idma64_chan *idma64c, bool drain) { unsigned short count = 100; u32 cfglo; cfglo = channel_readl(idma64c, CFG_LO); if (drain) cfglo |= IDMA64C_CFGL_CH_DRAIN; else cfglo &= ~IDMA64C_CFGL_CH_DRAIN; channel_writel(idma64c, CFG_LO, cfglo | IDMA64C_CFGL_CH_SUSP); do { udelay(1); cfglo = channel_readl(idma64c, CFG_LO); } while (!(cfglo & IDMA64C_CFGL_FIFO_EMPTY) && --count); } static void idma64_chan_activate(struct idma64_chan *idma64c) { u32 cfglo; cfglo = channel_readl(idma64c, CFG_LO); channel_writel(idma64c, CFG_LO, cfglo & ~IDMA64C_CFGL_CH_SUSP); } static int idma64_pause(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); unsigned long flags; spin_lock_irqsave(&idma64c->vchan.lock, flags); if (idma64c->desc && idma64c->desc->status == DMA_IN_PROGRESS) { idma64_chan_deactivate(idma64c, false); idma64c->desc->status = DMA_PAUSED; } spin_unlock_irqrestore(&idma64c->vchan.lock, flags); return 0; } static int idma64_resume(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); unsigned long flags; spin_lock_irqsave(&idma64c->vchan.lock, flags); if (idma64c->desc && idma64c->desc->status == DMA_PAUSED) { idma64c->desc->status = DMA_IN_PROGRESS; idma64_chan_activate(idma64c); } spin_unlock_irqrestore(&idma64c->vchan.lock, flags); return 0; } static int idma64_terminate_all(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); unsigned long flags; LIST_HEAD(head); spin_lock_irqsave(&idma64c->vchan.lock, flags); idma64_chan_deactivate(idma64c, true); idma64_stop_transfer(idma64c); if (idma64c->desc) { idma64_vdesc_free(&idma64c->desc->vdesc); idma64c->desc = NULL; } vchan_get_all_descriptors(&idma64c->vchan, &head); spin_unlock_irqrestore(&idma64c->vchan.lock, flags); vchan_dma_desc_free_list(&idma64c->vchan, &head); return 0; } static void idma64_synchronize(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); vchan_synchronize(&idma64c->vchan); } static int idma64_alloc_chan_resources(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); /* Create a pool of consistent memory blocks for hardware descriptors */ idma64c->pool = dma_pool_create(dev_name(chan2dev(chan)), chan->device->dev, sizeof(struct idma64_lli), 8, 0); if (!idma64c->pool) { dev_err(chan2dev(chan), "No memory for descriptors\n"); return -ENOMEM; } return 0; } static void idma64_free_chan_resources(struct dma_chan *chan) { struct idma64_chan *idma64c = to_idma64_chan(chan); vchan_free_chan_resources(to_virt_chan(chan)); dma_pool_destroy(idma64c->pool); idma64c->pool = NULL; } /* ---------------------------------------------------------------------- */ #define IDMA64_BUSWIDTHS \ BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) static int idma64_probe(struct idma64_chip *chip) { struct idma64 *idma64; unsigned short nr_chan = IDMA64_NR_CHAN; unsigned short i; int ret; idma64 = devm_kzalloc(chip->dev, sizeof(*idma64), GFP_KERNEL); if (!idma64) return -ENOMEM; idma64->regs = chip->regs; chip->idma64 = idma64; idma64->chan = devm_kcalloc(chip->dev, nr_chan, sizeof(*idma64->chan), GFP_KERNEL); if (!idma64->chan) return -ENOMEM; idma64->all_chan_mask = (1 << nr_chan) - 1; /* Turn off iDMA controller */ idma64_off(idma64); ret = devm_request_irq(chip->dev, chip->irq, idma64_irq, IRQF_SHARED, dev_name(chip->dev), idma64); if (ret) return ret; INIT_LIST_HEAD(&idma64->dma.channels); for (i = 0; i < nr_chan; i++) { struct idma64_chan *idma64c = &idma64->chan[i]; idma64c->vchan.desc_free = idma64_vdesc_free; vchan_init(&idma64c->vchan, &idma64->dma); idma64c->regs = idma64->regs + i * IDMA64_CH_LENGTH; idma64c->mask = BIT(i); } dma_cap_set(DMA_SLAVE, idma64->dma.cap_mask); dma_cap_set(DMA_PRIVATE, idma64->dma.cap_mask); idma64->dma.device_alloc_chan_resources = idma64_alloc_chan_resources; idma64->dma.device_free_chan_resources = idma64_free_chan_resources; idma64->dma.device_prep_slave_sg = idma64_prep_slave_sg; idma64->dma.device_issue_pending = idma64_issue_pending; idma64->dma.device_tx_status = idma64_tx_status; idma64->dma.device_config = idma64_slave_config; idma64->dma.device_pause = idma64_pause; idma64->dma.device_resume = idma64_resume; idma64->dma.device_terminate_all = idma64_terminate_all; idma64->dma.device_synchronize = idma64_synchronize; idma64->dma.src_addr_widths = IDMA64_BUSWIDTHS; idma64->dma.dst_addr_widths = IDMA64_BUSWIDTHS; idma64->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); idma64->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; idma64->dma.dev = chip->sysdev; dma_set_max_seg_size(idma64->dma.dev, IDMA64C_CTLH_BLOCK_TS_MASK); ret = dma_async_device_register(&idma64->dma); if (ret) return ret; dev_info(chip->dev, "Found Intel integrated DMA 64-bit\n"); return 0; } static void idma64_remove(struct idma64_chip *chip) { struct idma64 *idma64 = chip->idma64; unsigned short i; dma_async_device_unregister(&idma64->dma); /* * Explicitly call devm_request_irq() to avoid the side effects with * the scheduled tasklets. */ devm_free_irq(chip->dev, chip->irq, idma64); for (i = 0; i < idma64->dma.chancnt; i++) { struct idma64_chan *idma64c = &idma64->chan[i]; tasklet_kill(&idma64c->vchan.task); } } /* ---------------------------------------------------------------------- */ static int idma64_platform_probe(struct platform_device *pdev) { struct idma64_chip *chip; struct device *dev = &pdev->dev; struct device *sysdev = dev->parent; int ret; chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; chip->irq = platform_get_irq(pdev, 0); if (chip->irq < 0) return chip->irq; chip->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(chip->regs)) return PTR_ERR(chip->regs); ret = dma_coerce_mask_and_coherent(sysdev, DMA_BIT_MASK(64)); if (ret) return ret; chip->dev = dev; chip->sysdev = sysdev; ret = idma64_probe(chip); if (ret) return ret; platform_set_drvdata(pdev, chip); return 0; } static void idma64_platform_remove(struct platform_device *pdev) { struct idma64_chip *chip = platform_get_drvdata(pdev); idma64_remove(chip); } static int __maybe_unused idma64_pm_suspend(struct device *dev) { struct idma64_chip *chip = dev_get_drvdata(dev); idma64_off(chip->idma64); return 0; } static int __maybe_unused idma64_pm_resume(struct device *dev) { struct idma64_chip *chip = dev_get_drvdata(dev); idma64_on(chip->idma64); return 0; } static const struct dev_pm_ops idma64_dev_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(idma64_pm_suspend, idma64_pm_resume) }; static struct platform_driver idma64_platform_driver = { .probe = idma64_platform_probe, .remove_new = idma64_platform_remove, .driver = { .name = LPSS_IDMA64_DRIVER_NAME, .pm = &idma64_dev_pm_ops, }, }; module_platform_driver(idma64_platform_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("iDMA64 core driver"); MODULE_AUTHOR("Andy Shevchenko "); MODULE_ALIAS("platform:" LPSS_IDMA64_DRIVER_NAME);