* [PATCH 1/3] dt/bindings: bcm2835: add interrupt-names property
2016-03-17 15:24 [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
@ 2016-03-17 15:24 ` kernel at martin.sperl.org
2016-03-20 0:17 ` Rob Herring
2016-03-17 15:24 ` [PATCH 2/3] dmaengine: bcm2835: use platform_get_irq_byname kernel at martin.sperl.org
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: kernel at martin.sperl.org @ 2016-03-17 15:24 UTC (permalink / raw)
To: linux-arm-kernel
From: Martin Sperl <kernel@martin.sperl.org>
Added standard interrupt-names property so that
platform_get_irq_byname() can get used to fetch the
interrupt corresponding to each dma_channel
instead of the current platform_get_irq() with
an assumed ordering of the interrupts.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
.../devicetree/bindings/dma/brcm,bcm2835-dma.txt | 24 ++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
index 1396078..3035654 100644
--- a/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
+++ b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
@@ -12,6 +12,8 @@ Required properties:
- reg: Should contain DMA registers location and length.
- interrupts: Should contain the DMA interrupts associated
to the DMA channels in ascending order.
+- interrupt-names: Should contain the names of the interrupt
+ in the form "dmaXX".
- #dma-cells: Must be <1>, the cell in the dmas property of the
client device represents the DREQ number.
- brcm,dma-channel-mask: Bit mask representing the channels
@@ -34,13 +36,35 @@ dma: dma at 7e007000 {
<1 24>,
<1 25>,
<1 26>,
+ /* dma channel 11-14 share one irq */
<1 27>,
+ <1 27>,
+ <1 27>,
+ <1 27>,
+ /* unused shared irq for all channels */
<1 28>;
+ interrupt-names = "dma0",
+ "dma1",
+ "dma2",
+ "dma3",
+ "dma4",
+ "dma5",
+ "dma6",
+ "dma7",
+ "dma8",
+ "dma9",
+ "dma10",
+ "dma11",
+ "dma12",
+ "dma13",
+ "dma14",
+ "dma-shared-all";
#dma-cells = <1>;
brcm,dma-channel-mask = <0x7f35>;
};
+
DMA clients connected to the BCM2835 DMA controller must use the format
described in the dma.txt file, using a two-cell specifier for each channel.
--
2.1.4
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 1/3] dt/bindings: bcm2835: add interrupt-names property
2016-03-17 15:24 ` [PATCH 1/3] dt/bindings: bcm2835: add interrupt-names property kernel at martin.sperl.org
@ 2016-03-20 0:17 ` Rob Herring
0 siblings, 0 replies; 7+ messages in thread
From: Rob Herring @ 2016-03-20 0:17 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 17, 2016 at 03:24:31PM +0000, kernel at martin.sperl.org wrote:
> From: Martin Sperl <kernel@martin.sperl.org>
>
> Added standard interrupt-names property so that
> platform_get_irq_byname() can get used to fetch the
> interrupt corresponding to each dma_channel
> instead of the current platform_get_irq() with
> an assumed ordering of the interrupts.
>
> Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
> ---
> .../devicetree/bindings/dma/brcm,bcm2835-dma.txt | 24 ++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
Acked-by: Rob Herring <robh@kernel.org>
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-03-17 15:24 [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
2016-03-17 15:24 ` [PATCH 1/3] dt/bindings: bcm2835: add interrupt-names property kernel at martin.sperl.org
@ 2016-03-17 15:24 ` kernel at martin.sperl.org
2016-03-17 15:24 ` [PATCH 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping kernel at martin.sperl.org
2016-04-05 17:03 ` [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 Vinod Koul
3 siblings, 0 replies; 7+ messages in thread
From: kernel at martin.sperl.org @ 2016-03-17 15:24 UTC (permalink / raw)
To: linux-arm-kernel
From: Martin Sperl <kernel@martin.sperl.org>
Use platform_get_irq_byname to allow for correct mapping of
interrupts to dma channels.
The currently implemented device tree is unfortunately
implemented with the wrong assumption, that each dma-channel
has its own dma channel, but dma-irq 11 is handling
dma-channel 11-14 and dma-irq 12 is actually a "catch all"
interrupt.
So here we use the byname variant and require that interrupts
are explicitly named via the interrupts-name property in the
device tree.
The use of shared interrupts is also implemented.
As a side-effect this means we can now use dma channels 12, 13 and 14
in a correct manner - also testing shows that onl using
channels 11 to 14 for spi and i2s works perfectly (when playing
some video)
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
drivers/dma/bcm2835-dma.c | 77 ++++++++++++++++++++++++++++++++++++++---------
1 file changed, 63 insertions(+), 14 deletions(-)
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index cc771cd..9740151 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);
--
2.1.4
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping
2016-03-17 15:24 [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
2016-03-17 15:24 ` [PATCH 1/3] dt/bindings: bcm2835: add interrupt-names property kernel at martin.sperl.org
2016-03-17 15:24 ` [PATCH 2/3] dmaengine: bcm2835: use platform_get_irq_byname kernel at martin.sperl.org
@ 2016-03-17 15:24 ` kernel at martin.sperl.org
2016-04-05 17:03 ` [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 Vinod Koul
3 siblings, 0 replies; 7+ messages in thread
From: kernel at martin.sperl.org @ 2016-03-17 15:24 UTC (permalink / raw)
To: linux-arm-kernel
From: Martin Sperl <kernel@martin.sperl.org>
Add interrupt-names properties to dt and apply the correct
mapping between irq and dma channels.
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
arch/arm/boot/dts/bcm283x.dtsi | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index 971e741..a8342f6 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -46,9 +46,29 @@
<1 24>,
<1 25>,
<1 26>,
+ /* dma channel 11-14 share one irq */
<1 27>,
+ <1 27>,
+ <1 27>,
+ <1 27>,
+ /* unused shared irq for all channels */
<1 28>;
-
+ interrupt-names = "dma0",
+ "dma1",
+ "dma2",
+ "dma3",
+ "dma4",
+ "dma5",
+ "dma6",
+ "dma7",
+ "dma8",
+ "dma9",
+ "dma10",
+ "dma11",
+ "dma12",
+ "dma13",
+ "dma14",
+ "dma-shared-all";
#dma-cells = <1>;
brcm,dma-channel-mask = <0x7f35>;
};
--
2.1.4
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14
2016-03-17 15:24 [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
` (2 preceding siblings ...)
2016-03-17 15:24 ` [PATCH 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping kernel at martin.sperl.org
@ 2016-04-05 17:03 ` Vinod Koul
2016-04-08 18:37 ` Eric Anholt
3 siblings, 1 reply; 7+ messages in thread
From: Vinod Koul @ 2016-04-05 17:03 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 17, 2016 at 03:24:30PM +0000, kernel at martin.sperl.org wrote:
> From: Martin Sperl <kernel@martin.sperl.org>
>
> Right now the dma engine officially supports dma channel 11 and 12.
> But the use of dma channel 12 immediately stalls the system.
>
> The reason is that the interrupt assigned right now to dma channel 11
> is actually a shared interrupt for dma channels 11 to 12.
> So whenever the dma channel 12, 13 or 14 is used, it triggers the interrupt
> for dma 11 which only clears the interrupt flag for dma channel 11.
> This results in the interrupt 11 is triggered all the time.
>
> On top the requesting dma channel12 (and the corresponding irq) triggers
> an immeditate stall of the system, because for the 12th interrupt
> any dma channel will trigger also this interrupt - even if the dma channel
> is controlled by the firmware.
>
> As the description in the default device-tree is (for the above reasons)
> wrong a new means had to get devised that allows correct representation
> of the mapping between interrupts and dma channels.
>
> For this the existing (but unused) device-tree property "interrupt-names"
> is used to define the mapping.
This looks fine by me, need an ACK on ARM patch before this can be applied.
--
~Vinod
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14
2016-04-05 17:03 ` [PATCH 0/3] dmaengine: bcm2835: support dma channel 11 to 14 Vinod Koul
@ 2016-04-08 18:37 ` Eric Anholt
0 siblings, 0 replies; 7+ messages in thread
From: Eric Anholt @ 2016-04-08 18:37 UTC (permalink / raw)
To: linux-arm-kernel
Vinod Koul <vinod.koul@intel.com> writes:
> On Thu, Mar 17, 2016 at 03:24:30PM +0000, kernel at martin.sperl.org wrote:
>> From: Martin Sperl <kernel@martin.sperl.org>
>>
>> Right now the dma engine officially supports dma channel 11 and 12.
>> But the use of dma channel 12 immediately stalls the system.
>>
>> The reason is that the interrupt assigned right now to dma channel 11
>> is actually a shared interrupt for dma channels 11 to 12.
>> So whenever the dma channel 12, 13 or 14 is used, it triggers the interrupt
>> for dma 11 which only clears the interrupt flag for dma channel 11.
>> This results in the interrupt 11 is triggered all the time.
>>
>> On top the requesting dma channel12 (and the corresponding irq) triggers
>> an immeditate stall of the system, because for the 12th interrupt
>> any dma channel will trigger also this interrupt - even if the dma channel
>> is controlled by the firmware.
>>
>> As the description in the default device-tree is (for the above reasons)
>> wrong a new means had to get devised that allows correct representation
>> of the mapping between interrupts and dma channels.
>>
>> For this the existing (but unused) device-tree property "interrupt-names"
>> is used to define the mapping.
>
> This looks fine by me, need an ACK on ARM patch before this can be applied.
This series is:
Acked-by: Eric Anholt <eric@anholt.net>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20160408/ff8c6ca6/attachment.sig>
^ permalink raw reply [flat|nested] 7+ messages in thread