* [PATCH V2 1/3] dt/bindings: bcm2835: add interrupt-names property
2016-04-11 13:29 [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
@ 2016-04-11 13:29 ` kernel at martin.sperl.org
2016-04-11 13:29 ` [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname kernel at martin.sperl.org
` (2 subsequent siblings)
3 siblings, 0 replies; 9+ messages in thread
From: kernel at martin.sperl.org @ 2016-04-11 13:29 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>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
.../devicetree/bindings/dma/brcm,bcm2835-dma.txt | 26 ++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
index 1396078..baf9b34 100644
--- a/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
+++ b/Documentation/devicetree/bindings/dma/brcm,bcm2835-dma.txt
@@ -12,6 +12,10 @@ 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".
+ Use "dma-shared-all" for the common interrupt line
+ that is shared by all dma channels.
- #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 +38,35 @@ 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] 9+ messages in thread* [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-04-11 13:29 [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
2016-04-11 13:29 ` [PATCH V2 1/3] dt/bindings: bcm2835: add interrupt-names property kernel at martin.sperl.org
@ 2016-04-11 13:29 ` kernel at martin.sperl.org
2016-04-20 6:51 ` Geert Uytterhoeven
2016-04-11 13:29 ` [PATCH V2 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping kernel at martin.sperl.org
2016-04-19 15:33 ` [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 Vinod Koul
3 siblings, 1 reply; 9+ messages in thread
From: kernel at martin.sperl.org @ 2016-04-11 13:29 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>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
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] 9+ messages in thread* [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-04-11 13:29 ` [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname kernel at martin.sperl.org
@ 2016-04-20 6:51 ` Geert Uytterhoeven
2016-04-20 11:06 ` Martin Sperl
0 siblings, 1 reply; 9+ messages in thread
From: Geert Uytterhoeven @ 2016-04-20 6:51 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Apr 11, 2016 at 3:29 PM, <kernel@martin.sperl.org> wrote:
> 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
interrupt-names
> device tree.
>
> The use of shared interrupts is also implemented.
You're not explicitly looking for "dma-shared-all" for that?
You might as well just declare a single unnamed interrupt in the bindings.
> + /* legacy device tree case handling */
> + dev_warn_once(&pdev->dev,
> + "missing interrupts-names property in device tree - legacy interpretation is used");
interrupt-names
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-04-20 6:51 ` Geert Uytterhoeven
@ 2016-04-20 11:06 ` Martin Sperl
2016-04-20 11:12 ` Geert Uytterhoeven
0 siblings, 1 reply; 9+ messages in thread
From: Martin Sperl @ 2016-04-20 11:06 UTC (permalink / raw)
To: linux-arm-kernel
On 20.04.2016 08:51, Geert Uytterhoeven wrote:
> On Mon, Apr 11, 2016 at 3:29 PM, <kernel@martin.sperl.org> wrote:
>> 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
>
> interrupt-names
Vinod has just merged this patch - do you want me to submit another
to correct those?
> You're not explicitly looking for "dma-shared-all" for that?
> You might as well just declare a single unnamed interrupt in the bindings.
dma-shared-all is unfortunately an interrupt-line that triggers
for interrupt-channels 0-15 and that includes the dma channels
that are owned by the firmware.
It is there mostly to document the interrupt-line (which is there in the
existing device tree files - it is not used.
Martin
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-04-20 11:06 ` Martin Sperl
@ 2016-04-20 11:12 ` Geert Uytterhoeven
2016-04-20 13:11 ` Vinod Koul
0 siblings, 1 reply; 9+ messages in thread
From: Geert Uytterhoeven @ 2016-04-20 11:12 UTC (permalink / raw)
To: linux-arm-kernel
Hi Martin,
On Wed, Apr 20, 2016 at 1:06 PM, Martin Sperl <kernel@martin.sperl.org> wrote:
> On 20.04.2016 08:51, Geert Uytterhoeven wrote:
>>
>> On Mon, Apr 11, 2016 at 3:29 PM, <kernel@martin.sperl.org> wrote:
>>>
>>> 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
>>
>> interrupt-names
>
> Vinod has just merged this patch - do you want me to submit another
Yeah, that's how I noticed by accident :-)
> to correct those?
For the commit message it's indeed too late. For the error message in the
code, yes please.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname
2016-04-20 11:12 ` Geert Uytterhoeven
@ 2016-04-20 13:11 ` Vinod Koul
0 siblings, 0 replies; 9+ messages in thread
From: Vinod Koul @ 2016-04-20 13:11 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Apr 20, 2016 at 01:12:36PM +0200, Geert Uytterhoeven wrote:
> Hi Martin,
>
> On Wed, Apr 20, 2016 at 1:06 PM, Martin Sperl <kernel@martin.sperl.org> wrote:
> > On 20.04.2016 08:51, Geert Uytterhoeven wrote:
> >>
> >> On Mon, Apr 11, 2016 at 3:29 PM, <kernel@martin.sperl.org> wrote:
> >>>
> >>> 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
> >>
> >> interrupt-names
well spotted
> >
> > Vinod has just merged this patch - do you want me to submit another
>
> Yeah, that's how I noticed by accident :-)
>
> > to correct those?
>
> For the commit message it's indeed too late. For the error message in the
> code, yes please.
I can drop the branch
--
~Vinod
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH V2 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping
2016-04-11 13:29 [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
2016-04-11 13:29 ` [PATCH V2 1/3] dt/bindings: bcm2835: add interrupt-names property kernel at martin.sperl.org
2016-04-11 13:29 ` [PATCH V2 2/3] dmaengine: bcm2835: use platform_get_irq_byname kernel at martin.sperl.org
@ 2016-04-11 13:29 ` kernel at martin.sperl.org
2016-04-19 15:33 ` [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 Vinod Koul
3 siblings, 0 replies; 9+ messages in thread
From: kernel at martin.sperl.org @ 2016-04-11 13:29 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>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Eric Anholt <eric@anholt.net>
---
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 8aaf193..84dcf3e 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -47,9 +47,29 @@
<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] 9+ messages in thread
* [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14
2016-04-11 13:29 [PATCH V2 0/3] dmaengine: bcm2835: support dma channel 11 to 14 kernel at martin.sperl.org
` (2 preceding siblings ...)
2016-04-11 13:29 ` [PATCH V2 3/3] ARM: bcm2835: add interrupt-names and apply correct mapping kernel at martin.sperl.org
@ 2016-04-19 15:33 ` Vinod Koul
3 siblings, 0 replies; 9+ messages in thread
From: Vinod Koul @ 2016-04-19 15:33 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Apr 11, 2016 at 01:29:06PM +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.
>
> Implementing shared interrupts is another necessity when using dma channel
> 11 to 14, so it is a part of this patch.
Applied, thanks
--
~Vinod
^ permalink raw reply [flat|nested] 9+ messages in thread