diff mbox

[3/9] ARM: edma: Add function to manually trigger an EDMA channel

Message ID 1375104595-16018-4-git-send-email-joelf@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Joel Fernandes July 29, 2013, 1:29 p.m. UTC
Manual trigger for events missed as a result of splitting a
scatter gather list and DMA'ing it in batches. Add a helper
function to trigger a channel incase any such events are missed.

Signed-off-by: Joel Fernandes <joelf@ti.com>
---
 arch/arm/common/edma.c             |   21 +++++++++++++++++++++
 include/linux/platform_data/edma.h |    2 ++
 2 files changed, 23 insertions(+)

Comments

Sekhar Nori July 30, 2013, 5:18 a.m. UTC | #1
On Monday 29 July 2013 06:59 PM, Joel Fernandes wrote:
> Manual trigger for events missed as a result of splitting a
> scatter gather list and DMA'ing it in batches. Add a helper
> function to trigger a channel incase any such events are missed.
> 
> Signed-off-by: Joel Fernandes <joelf@ti.com>
> ---
>  arch/arm/common/edma.c             |   21 +++++++++++++++++++++
>  include/linux/platform_data/edma.h |    2 ++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
> index 3567ba1..10995b2 100644
> --- a/arch/arm/common/edma.c
> +++ b/arch/arm/common/edma.c
> @@ -1236,6 +1236,27 @@ void edma_resume(unsigned channel)
>  }
>  EXPORT_SYMBOL(edma_resume);
>  
> +int edma_manual_trigger(unsigned channel)

edma_trigger_channel() maybe? Brings consistency with
edma_alloc_channel() edma_free_channel() etc.

> +{
> +	unsigned ctlr;
> +	int j;
> +	unsigned int mask;
> +
> +	ctlr = EDMA_CTLR(channel);
> +	channel = EDMA_CHAN_SLOT(channel);
> +	mask = BIT(channel & 0x1f);
> +
> +	j = channel >> 5;
> +
> +	/* EDMA channels without event association */

May be actually check for no-event association before you trigger in
software? You can do that by looking at unused channel list, no?

> +	edma_shadow0_write_array(ctlr, SH_ESR, j, mask);

edma_shadow0_write_array(ctlr, SH_ESR, channel >> 5, mask) is no less
readable, but I leave it to you.

Thanks,
Sekhar

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Joel Fernandes July 31, 2013, 4:30 a.m. UTC | #2
On 07/30/2013 12:18 AM, Sekhar Nori wrote:
> On Monday 29 July 2013 06:59 PM, Joel Fernandes wrote:
>> Manual trigger for events missed as a result of splitting a
>> scatter gather list and DMA'ing it in batches. Add a helper
>> function to trigger a channel incase any such events are missed.
>>
>> Signed-off-by: Joel Fernandes <joelf@ti.com>
>> ---
>>  arch/arm/common/edma.c             |   21 +++++++++++++++++++++
>>  include/linux/platform_data/edma.h |    2 ++
>>  2 files changed, 23 insertions(+)
>>
>> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
>> index 3567ba1..10995b2 100644
>> --- a/arch/arm/common/edma.c
>> +++ b/arch/arm/common/edma.c
>> @@ -1236,6 +1236,27 @@ void edma_resume(unsigned channel)
>>  }
>>  EXPORT_SYMBOL(edma_resume);
>>  
>> +int edma_manual_trigger(unsigned channel)
> 
> edma_trigger_channel() maybe? Brings consistency with
> edma_alloc_channel() edma_free_channel() etc.

Ok, sure.

> 
>> +{
>> +	unsigned ctlr;
>> +	int j;
>> +	unsigned int mask;
>> +
>> +	ctlr = EDMA_CTLR(channel);
>> +	channel = EDMA_CHAN_SLOT(channel);
>> +	mask = BIT(channel & 0x1f);
>> +
>> +	j = channel >> 5;
>> +
>> +	/* EDMA channels without event association */
> 
> May be actually check for no-event association before you trigger in
> software? You can do that by looking at unused channel list, no?

But, we want to trigger whether there is event association or not in
this function. For ex, MMC has event associated but still this function
is used to trigger event for it.

> 
>> +	edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
> 
> edma_shadow0_write_array(ctlr, SH_ESR, channel >> 5, mask) is no less
> readable, but I leave it to you.

Sure that's more readable, will changed it to that.

Thanks,

-Joel

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Sekhar Nori July 31, 2013, 5:23 a.m. UTC | #3
On Wednesday 31 July 2013 10:00 AM, Joel Fernandes wrote:
> On 07/30/2013 12:18 AM, Sekhar Nori wrote:
>> On Monday 29 July 2013 06:59 PM, Joel Fernandes wrote:
>>> Manual trigger for events missed as a result of splitting a
>>> scatter gather list and DMA'ing it in batches. Add a helper
>>> function to trigger a channel incase any such events are missed.
>>>
>>> Signed-off-by: Joel Fernandes <joelf@ti.com>
>>> ---
>>>  arch/arm/common/edma.c             |   21 +++++++++++++++++++++
>>>  include/linux/platform_data/edma.h |    2 ++
>>>  2 files changed, 23 insertions(+)
>>>
>>> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
>>> index 3567ba1..10995b2 100644
>>> --- a/arch/arm/common/edma.c
>>> +++ b/arch/arm/common/edma.c
>>> @@ -1236,6 +1236,27 @@ void edma_resume(unsigned channel)
>>>  }
>>>  EXPORT_SYMBOL(edma_resume);
>>>  
>>> +int edma_manual_trigger(unsigned channel)
>>
>> edma_trigger_channel() maybe? Brings consistency with
>> edma_alloc_channel() edma_free_channel() etc.
> 
> Ok, sure.
> 
>>
>>> +{
>>> +	unsigned ctlr;
>>> +	int j;
>>> +	unsigned int mask;
>>> +
>>> +	ctlr = EDMA_CTLR(channel);
>>> +	channel = EDMA_CHAN_SLOT(channel);
>>> +	mask = BIT(channel & 0x1f);
>>> +
>>> +	j = channel >> 5;
>>> +
>>> +	/* EDMA channels without event association */
>>
>> May be actually check for no-event association before you trigger in
>> software? You can do that by looking at unused channel list, no?
> 
> But, we want to trigger whether there is event association or not in
> this function. For ex, MMC has event associated but still this function
> is used to trigger event for it.

Okay, just drop the misleading comment then.

Regards,
Sekhar
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diff mbox

Patch

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 3567ba1..10995b2 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -1236,6 +1236,27 @@  void edma_resume(unsigned channel)
 }
 EXPORT_SYMBOL(edma_resume);
 
+int edma_manual_trigger(unsigned channel)
+{
+	unsigned ctlr;
+	int j;
+	unsigned int mask;
+
+	ctlr = EDMA_CTLR(channel);
+	channel = EDMA_CHAN_SLOT(channel);
+	mask = BIT(channel & 0x1f);
+
+	j = channel >> 5;
+
+	/* EDMA channels without event association */
+	edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
+
+	pr_debug("EDMA: ESR%d %08x\n", j,
+		 edma_shadow0_read_array(ctlr, SH_ESR, j));
+	return 0;
+}
+EXPORT_SYMBOL(edma_manual_trigger);
+
 /**
  * edma_start - start dma on a channel
  * @channel: channel being activated
diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h
index 57300fd..0e11eca 100644
--- a/include/linux/platform_data/edma.h
+++ b/include/linux/platform_data/edma.h
@@ -180,4 +180,6 @@  struct edma_soc_info {
 	const s16	(*xbar_chans)[2];
 };
 
+int edma_manual_trigger(unsigned);
+
 #endif