Re: [PATCH 2/3] dma: arm-dma350: add support for shared interrupt mode

Jun Guo
2025-11-17T11:37:25Z

On 11/17/2025 2:13 PM, Krzysztof Kozlowski wrote:
> On 17/11/2025 02:59, Jun Guo wrote:
>> - The arm dma350 controller's hardware implementation varies: some
> That's not a list. Look at git history to learn how to write expected
> commit messages.
>
>> designs dedicate a separate interrupt line for each channel, while
>> others have all channels sharing a single interrupt.This patch adds
>> support for the hardware design where all DMA channels share a
>> single interrupt.
>>
>> Signed-off-by: Jun Guo<jun.guo@cixtech.com>
>> ---
>> drivers/dma/ar
>
>
>> @@ -526,7 +593,7 @@ static void d350_free_chan_resources(struct dma_chan *chan)
>> 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;
>> @@ -556,6 +623,7 @@ 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);
>> @@ -582,6 +650,26 @@ static int d350_probe(struct platform_device *pdev)
>> dmac->dma.device_issue_pending = d350_issue_pending;
>> INIT_LIST_HEAD(&dmac->dma.channels);
>>
>> + /* Cix Sky1 has a common host IRQ for all its channels. */
>> + if (of_device_is_compatible(pdev->dev.of_node, "cix,sky1-dma-350")) {
> No, see further
>
>> + 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++) {
>> @@ -595,10 +683,16 @@ 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 (!of_device_is_compatible(pdev->dev.of_node,
>> + "cix,sky1-dma-350")) {
> No, use driver match data for that. Sprinkling compatibles everywhere
> does not scale.
>
I have another question: by "driver match data", are you referring to
the data variable in the struct of_device_id?
> Also, this is in contrary with the binding, which did not say your
> device has no interrupts.
I need to clarify here: the issue with my chip platform is not the lack
of interrupts, but that all DMA channels share a single interrupt. The
current driver, however, defaults to assigning an individual interrupt
for each DMA channel.