diff options
Diffstat (limited to 'drivers/dma/bcm2835-dma.c')
| -rw-r--r-- | drivers/dma/bcm2835-dma.c | 77 |
1 files changed, 63 insertions, 14 deletions
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index cc771cd35dd0..974015193b93 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -46,6 +46,9 @@ #include "virt-dma.h" +#define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14 +#define BCM2835_DMA_CHAN_NAME_SIZE 8 + struct bcm2835_dmadev { struct dma_device ddev; spinlock_t lock; @@ -81,6 +84,7 @@ struct bcm2835_chan { void __iomem *chan_base; int irq_number; + unsigned int irq_flags; bool is_lite_channel; }; @@ -466,6 +470,15 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data) struct bcm2835_desc *d; unsigned long flags; + /* check the shared interrupt */ + if (c->irq_flags & IRQF_SHARED) { + /* check if the interrupt is enabled */ + flags = readl(c->chan_base + BCM2835_DMA_CS); + /* if not set then we are not the reason for the irq */ + if (!(flags & BCM2835_DMA_INT)) + return IRQ_NONE; + } + spin_lock_irqsave(&c->vc.lock, flags); /* Acknowledge interrupt */ @@ -506,8 +519,8 @@ static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) return -ENOMEM; } - return request_irq(c->irq_number, - bcm2835_dma_callback, 0, "DMA IRQ", c); + return request_irq(c->irq_number, bcm2835_dma_callback, + c->irq_flags, "DMA IRQ", c); } static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) @@ -819,7 +832,8 @@ static int bcm2835_dma_terminate_all(struct dma_chan *chan) return 0; } -static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq) +static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, + int irq, unsigned int irq_flags) { struct bcm2835_chan *c; @@ -834,6 +848,7 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id, int irq) c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id); c->ch = chan_id; c->irq_number = irq; + c->irq_flags = irq_flags; /* check in DEBUG register if this is a LITE channel */ if (readl(c->chan_base + BCM2835_DMA_DEBUG) & @@ -882,9 +897,11 @@ static int bcm2835_dma_probe(struct platform_device *pdev) struct resource *res; void __iomem *base; int rc; - int i; - int irq; + int i, j; + int irq[BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED + 1]; + int irq_flags; uint32_t chans_available; + char chan_name[BCM2835_DMA_CHAN_NAME_SIZE]; if (!pdev->dev.dma_mask) pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; @@ -941,16 +958,48 @@ static int bcm2835_dma_probe(struct platform_device *pdev) goto err_no_dma; } - for (i = 0; i < pdev->num_resources; i++) { - irq = platform_get_irq(pdev, i); - if (irq < 0) - break; - - if (chans_available & (1 << i)) { - rc = bcm2835_dma_chan_init(od, i, irq); - if (rc) - goto err_no_dma; + /* get irqs for each channel that we support */ + for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) { + /* skip masked out channels */ + if (!(chans_available & (1 << i))) { + irq[i] = -1; + continue; } + + /* get the named irq */ + snprintf(chan_name, sizeof(chan_name), "dma%i", i); + irq[i] = platform_get_irq_byname(pdev, chan_name); + if (irq[i] >= 0) + continue; + + /* legacy device tree case handling */ + dev_warn_once(&pdev->dev, + "missing interrupts-names property in device tree - legacy interpretation is used"); + /* + * in case of channel >= 11 + * use the 11th interrupt and that is shared + */ + irq[i] = platform_get_irq(pdev, i < 11 ? i : 11); + } + + /* get irqs for each channel */ + for (i = 0; i <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; i++) { + /* skip channels without irq */ + if (irq[i] < 0) + continue; + + /* check if there are other channels that also use this irq */ + irq_flags = 0; + for (j = 0; j <= BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED; j++) + if ((i != j) && (irq[j] == irq[i])) { + irq_flags = IRQF_SHARED; + break; + } + + /* initialize the channel */ + rc = bcm2835_dma_chan_init(od, i, irq[i], irq_flags); + if (rc) + goto err_no_dma; } dev_dbg(&pdev->dev, "Initialized %i DMA channels\n", i); |