[PATCH v3 2/3] dma: arm-dma350: support combined IRQ mode with runtime IRQ topology detection
From: Jun Guo <hidden>
Date: 2026-03-19 10:17:32
Also in:
dmaengine, linux-devicetree, lkml
Subsystem:
arm/nuvoton ma35 architecture, dma generic offload engine subsystem, the rest · Maintainers:
Jacky Huang, Shan-Chun Hung, Vinod Koul, Linus Torvalds
DMA-350 can be integrated with either per-channel IRQ lines or a single combined IRQ line. Add support for both layouts in a unified way. Detect IRQ topology at probe time via platform_irq_count(), then: - request one global IRQ and enable DMANSECCTRL.INTREN_ANYCHINTR for combined mode, or - request per-channel IRQs for channel mode. Refactor IRQ completion/error handling into a shared channel handler used by both global and per-channel IRQ paths, and guard against IRQs arriving without an active descriptor. This patch is Assisted-by: Cursor: GPT-5.3 Codex. Signed-off-by: Jun Guo <redacted> Link: https://lore.kernel.org/r/20251216123026.3519923-3-jun.guo@cixtech.com (local) --- drivers/dma/arm-dma350.c | 165 +++++++++++++++++++++++++++++++++------ 1 file changed, 139 insertions(+), 26 deletions(-)
diff --git a/drivers/dma/arm-dma350.c b/drivers/dma/arm-dma350.c
index 84220fa83029..2cf6f783b44f 100644
--- a/drivers/dma/arm-dma350.c
+++ b/drivers/dma/arm-dma350.c@@ -14,6 +14,7 @@ #include "virt-dma.h" #define DMAINFO 0x0f00 +#define DRIVER_NAME "arm-dma350" #define DMA_BUILDCFG0 0xb0 #define DMA_CFG_DATA_WIDTH GENMASK(18, 16)
@@ -142,6 +143,9 @@ #define LINK_LINKADDR BIT(30) #define LINK_LINKADDRHI BIT(31) +/* DMA NONSECURE CONTROL REGISTER */ +#define DMANSECCTRL 0x20c +#define INTREN_ANYCHINTR_EN BIT(0) enum ch_ctrl_donetype { CH_CTRL_DONETYPE_NONE = 0,
@@ -192,6 +196,7 @@ struct d350_chan { struct d350 { struct dma_device dma; + void __iomem *base; int nchan; int nreq; struct d350_chan channels[] __counted_by(nchan);
@@ -461,18 +466,40 @@ static void d350_issue_pending(struct dma_chan *chan) spin_unlock_irqrestore(&dch->vc.lock, flags); } -static irqreturn_t d350_irq(int irq, void *data) +static void d350_handle_chan_irq(struct d350_chan *dch, struct device *dev, + int chan_id, u32 ch_status) { - struct d350_chan *dch = data; - struct device *dev = dch->vc.chan.device->dev; - struct virt_dma_desc *vd = &dch->desc->vd; - u32 ch_status; + struct virt_dma_desc *vd; + bool intr_done = ch_status & CH_STAT_INTR_DONE; + bool intr_err = ch_status & CH_STAT_INTR_ERR; - ch_status = readl(dch->base + CH_STATUS); - if (!ch_status) - return IRQ_NONE; + if (!intr_done && !intr_err) { + if (chan_id >= 0) + dev_warn(dev, "Channel %d unexpected IRQ: 0x%08x\n", + chan_id, ch_status); + else + dev_warn(dev, "Unexpected IRQ source? 0x%08x\n", ch_status); + writel_relaxed(ch_status, dch->base + CH_STATUS); + return; + } + + writel_relaxed(ch_status, dch->base + CH_STATUS); + + spin_lock(&dch->vc.lock); + if (!dch->desc) { + if (chan_id >= 0) + dev_warn(dev, + "Channel %d IRQ without active descriptor: 0x%08x\n", + chan_id, ch_status); + else + dev_warn(dev, "IRQ without active descriptor: 0x%08x\n", + ch_status); + spin_unlock(&dch->vc.lock); + return; + } - if (ch_status & CH_STAT_INTR_ERR) { + vd = &dch->desc->vd; + if (intr_err) { u32 errinfo = readl_relaxed(dch->base + CH_ERRINFO); if (errinfo & (CH_ERRINFO_AXIRDPOISERR | CH_ERRINFO_AXIRDRESPERR))
@@ -483,14 +510,10 @@ static irqreturn_t d350_irq(int irq, void *data) vd->tx_result.result = DMA_TRANS_ABORTED; vd->tx_result.residue = d350_get_residue(dch); - } else if (!(ch_status & CH_STAT_INTR_DONE)) { - dev_warn(dev, "Unexpected IRQ source? 0x%08x\n", ch_status); } - writel_relaxed(ch_status, dch->base + CH_STATUS); - spin_lock(&dch->vc.lock); vchan_cookie_complete(vd); - if (ch_status & CH_STAT_INTR_DONE) { + if (intr_done) { dch->status = DMA_COMPLETE; dch->residue = 0; d350_start_next(dch);
@@ -499,6 +522,44 @@ static irqreturn_t d350_irq(int irq, void *data) dch->residue = vd->tx_result.residue; } spin_unlock(&dch->vc.lock); +} + +static irqreturn_t d350_global_irq(int irq, void *data) +{ + struct d350 *dmac = (struct d350 *)data; + irqreturn_t ret = IRQ_NONE; + int i; + + (void)irq; + + for (i = 0; i < dmac->nchan; i++) { + struct d350_chan *dch = &dmac->channels[i]; + u32 ch_status; + + ch_status = readl(dch->base + CH_STATUS); + if (!ch_status) + continue; + + ret = IRQ_HANDLED; + d350_handle_chan_irq(dch, dmac->dma.dev, i, ch_status); + } + + return ret; +} + +static irqreturn_t d350_channel_irq(int irq, void *data) +{ + struct d350_chan *dch = data; + struct device *dev = dch->vc.chan.device->dev; + u32 ch_status; + + (void)irq; + + ch_status = readl(dch->base + CH_STATUS); + if (!ch_status) + return IRQ_NONE; + + d350_handle_chan_irq(dch, dev, -1, ch_status); return IRQ_HANDLED; }
@@ -506,10 +567,18 @@ static irqreturn_t d350_irq(int irq, void *data) static int d350_alloc_chan_resources(struct dma_chan *chan) { struct d350_chan *dch = to_d350_chan(chan); - int ret = request_irq(dch->irq, d350_irq, IRQF_SHARED, - dev_name(&dch->vc.chan.dev->device), dch); - if (!ret) - writel_relaxed(CH_INTREN_DONE | CH_INTREN_ERR, dch->base + CH_INTREN); + int ret = 0; + + if (dch->irq >= 0) { + ret = request_irq(dch->irq, d350_channel_irq, IRQF_SHARED, + dev_name(&dch->vc.chan.dev->device), dch); + if (ret) { + dev_err(chan->device->dev, "Failed to request IRQ %d\n", dch->irq); + return ret; + } + } + + writel_relaxed(CH_INTREN_DONE | CH_INTREN_ERR, dch->base + CH_INTREN); return ret; }
@@ -519,18 +588,21 @@ static void d350_free_chan_resources(struct dma_chan *chan) struct d350_chan *dch = to_d350_chan(chan); writel_relaxed(0, dch->base + CH_INTREN); - free_irq(dch->irq, dch); + if (dch->irq >= 0) { + free_irq(dch->irq, dch); + dch->irq = -EINVAL; + } vchan_free_chan_resources(&dch->vc); } static int d350_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; - struct d350 *dmac; + struct d350 *dmac = NULL; void __iomem *base; u32 reg; - int ret, nchan, dw, aw, r, p; - bool coherent, memset; + int ret, nchan, dw, aw, r, p, irq_count; + bool coherent, memset, combined_irq; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base))
@@ -556,6 +628,7 @@ static int d350_probe(struct platform_device *pdev) return -ENOMEM; dmac->nchan = nchan; + dmac->base = base; reg = readl_relaxed(base + DMAINFO + DMA_BUILDCFG1); dmac->nreq = FIELD_GET(DMA_CFG_NUM_TRIGGER_IN, reg);
@@ -582,12 +655,46 @@ static int d350_probe(struct platform_device *pdev) dmac->dma.device_issue_pending = d350_issue_pending; INIT_LIST_HEAD(&dmac->dma.channels); + irq_count = platform_irq_count(pdev); + if (irq_count < 0) + return dev_err_probe(dev, irq_count, + "Failed to count interrupts\n"); + + if (irq_count == 1) { + combined_irq = true; + } else if (irq_count >= nchan) { + combined_irq = false; + } else { + return dev_err_probe(dev, -EINVAL, + "Invalid IRQ count %d for %d channels\n", + irq_count, nchan); + } + + if (combined_irq) { + int host_irq = platform_get_irq(pdev, 0); + + if (host_irq < 0) + return dev_err_probe(dev, host_irq, + "Failed to get IRQ\n"); + + ret = devm_request_irq(&pdev->dev, host_irq, d350_global_irq, + IRQF_SHARED, DRIVER_NAME, dmac); + if (ret) + return dev_err_probe( + dev, ret, + "Failed to request the combined IRQ %d\n", + host_irq); + /* Combined Non-Secure Channel Interrupt Enable */ + writel_relaxed(INTREN_ANYCHINTR_EN, dmac->base + DMANSECCTRL); + } + /* Would be nice to have per-channel caps for this... */ memset = true; for (int i = 0; i < nchan; i++) { struct d350_chan *dch = &dmac->channels[i]; dch->base = base + DMACH(i); + dch->irq = -EINVAL; writel_relaxed(CH_CMD_CLEAR, dch->base + CH_CMD); reg = readl_relaxed(dch->base + CH_BUILDCFG1);
@@ -595,10 +702,15 @@ static int d350_probe(struct platform_device *pdev) dev_warn(dev, "No command link support on channel %d\n", i); continue; } - dch->irq = platform_get_irq(pdev, i); - if (dch->irq < 0) - return dev_err_probe(dev, dch->irq, - "Failed to get IRQ for channel %d\n", i); + + if (!combined_irq) { + dch->irq = platform_get_irq(pdev, i); + if (dch->irq < 0) + return dev_err_probe( + dev, dch->irq, + "Failed to get IRQ for channel %d\n", + i); + } dch->has_wrap = FIELD_GET(CH_CFG_HAS_WRAP, reg); dch->has_trig = FIELD_GET(CH_CFG_HAS_TRIGIN, reg) &
@@ -640,6 +752,7 @@ static void d350_remove(struct platform_device *pdev) } static const struct of_device_id d350_of_match[] __maybe_unused = { + { .compatible = "cix,sky1-dma-350" }, { .compatible = "arm,dma-350" }, {} };
--
2.34.1