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* [PATCH v2] OMAP: DMA: Add API for setting channel dest addr
@ 2010-03-02 13:36 Manjunatha GK
  2010-03-02 13:51 ` Venkatraman S
  0 siblings, 1 reply; 3+ messages in thread
From: Manjunatha GK @ 2010-03-02 13:36 UTC (permalink / raw)
  To: linux-omap
  Cc: Manjunatha GK, Tony Lindgren, Santosh Shilimkar, S, Venkatraman,
	Govindraj R

The new API - omap_set_dma_dst_pos(int lch, int value) is added
for setting channel destination address in CPC/CDAC register

Cc: Tony Lindgren <tony@atomide.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: S, Venkatraman <svenkatr@ti.com>
Signed-off-by: Manjunatha GK <manjugk@ti.com>
Signed-off-by: Govindraj R <govindraj.raja@ti.com>
---
 arch/arm/plat-omap/dma.c              |   17 +++++++++++++++++
 arch/arm/plat-omap/include/plat/dma.h |    1 +
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index 2ab224c..c73f11a 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -1109,6 +1109,23 @@ dma_addr_t omap_get_dma_dst_pos(int lch)
 }
 EXPORT_SYMBOL(omap_get_dma_dst_pos);
 
+/**
+ * omap_set_dma_dst_pos() - Set DMA channel destination address
+ * @arg1:  lch      DMA logical channel number
+ * @arg2:  value    Value to write into CDAC register
+ *
+ * Writes "value" into the register CPC/CDAC
+ */
+void omap_set_dma_dst_pos(int lch, int value)
+{
+	if (cpu_is_omap15xx())
+		dma_write(value, CPC(lch));
+	else
+		dma_write(value, CDAC(lch));
+
+}
+EXPORT_SYMBOL(omap_set_dma_dst_pos);
+
 int omap_get_dma_active_status(int lch)
 {
 	return (dma_read(CCR(lch)) & OMAP_DMA_CCR_EN) != 0;
diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h
index 02232ca..3b6e43e 100644
--- a/arch/arm/plat-omap/include/plat/dma.h
+++ b/arch/arm/plat-omap/include/plat/dma.h
@@ -509,6 +509,7 @@ extern int omap_set_dma_callback(int lch,
 			void *data);
 extern dma_addr_t omap_get_dma_src_pos(int lch);
 extern dma_addr_t omap_get_dma_dst_pos(int lch);
+extern void omap_set_dma_dst_pos(int lch, int value);
 extern void omap_clear_dma(int lch);
 extern int omap_get_dma_active_status(int lch);
 extern int omap_dma_running(void);
-- 
1.6.0.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] OMAP: DMA: Add API for setting channel dest addr
  2010-03-02 13:36 [PATCH v2] OMAP: DMA: Add API for setting channel dest addr Manjunatha GK
@ 2010-03-02 13:51 ` Venkatraman S
  2010-03-02 17:16   ` Kevin Hilman
  0 siblings, 1 reply; 3+ messages in thread
From: Venkatraman S @ 2010-03-02 13:51 UTC (permalink / raw)
  To: Manjunatha GK; +Cc: linux-omap, Tony Lindgren, Santosh Shilimkar, Govindraj R

Manjunath,

On Tue, Mar 2, 2010 at 7:06 PM, Manjunatha GK <manjugk@ti.com> wrote:
> The new API - omap_set_dma_dst_pos(int lch, int value) is added
> for setting channel destination address in CPC/CDAC register
>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Cc: S, Venkatraman <svenkatr@ti.com>
> Signed-off-by: Manjunatha GK <manjugk@ti.com>
> Signed-off-by: Govindraj R <govindraj.raja@ti.com>
> ---
>  arch/arm/plat-omap/dma.c              |   17 +++++++++++++++++
>  arch/arm/plat-omap/include/plat/dma.h |    1 +
>  2 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
> index 2ab224c..c73f11a 100644
> --- a/arch/arm/plat-omap/dma.c
> +++ b/arch/arm/plat-omap/dma.c
> @@ -1109,6 +1109,23 @@ dma_addr_t omap_get_dma_dst_pos(int lch)
>  }
>  EXPORT_SYMBOL(omap_get_dma_dst_pos);
>
> +/**
> + * omap_set_dma_dst_pos() - Set DMA channel destination address
> + * @arg1:  lch      DMA logical channel number
> + * @arg2:  value    Value to write into CDAC register
> + *
> + * Writes "value" into the register CPC/CDAC
> + */
> +void omap_set_dma_dst_pos(int lch, int value)
> +{
> +       if (cpu_is_omap15xx())
> +               dma_write(value, CPC(lch));
> +       else
> +               dma_write(value, CDAC(lch));
> +
> +}
> +EXPORT_SYMBOL(omap_set_dma_dst_pos);
> +
>  int omap_get_dma_active_status(int lch)
>  {
>        return (dma_read(CCR(lch)) & OMAP_DMA_CCR_EN) != 0;
> diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h
> index 02232ca..3b6e43e 100644
> --- a/arch/arm/plat-omap/include/plat/dma.h
> +++ b/arch/arm/plat-omap/include/plat/dma.h
> @@ -509,6 +509,7 @@ extern int omap_set_dma_callback(int lch,
>                        void *data);
>  extern dma_addr_t omap_get_dma_src_pos(int lch);
>  extern dma_addr_t omap_get_dma_dst_pos(int lch);
> +extern void omap_set_dma_dst_pos(int lch, int value);
>  extern void omap_clear_dma(int lch);
>  extern int omap_get_dma_active_status(int lch);
>  extern int omap_dma_running(void);
> --
 CDAC is not the destination address, as the API seems to suggest.
CDSA (Channel Destination Start Address) is.

CDAC is a running counter of the current transfer.
I propose to update the omap_start_dma to reset CDAC to 0 always.

Best regards,
Venkat.
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^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] OMAP: DMA: Add API for setting channel dest addr
  2010-03-02 13:51 ` Venkatraman S
@ 2010-03-02 17:16   ` Kevin Hilman
  0 siblings, 0 replies; 3+ messages in thread
From: Kevin Hilman @ 2010-03-02 17:16 UTC (permalink / raw)
  To: Venkatraman S
  Cc: Manjunatha GK, linux-omap, Tony Lindgren, Santosh Shilimkar, Govindraj R

Venkatraman S <svenkatr@ti.com> writes:

> Manjunath,
>
> On Tue, Mar 2, 2010 at 7:06 PM, Manjunatha GK <manjugk@ti.com> wrote:
>> The new API - omap_set_dma_dst_pos(int lch, int value) is added
>> for setting channel destination address in CPC/CDAC register
>>
>> Cc: Tony Lindgren <tony@atomide.com>
>> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> Cc: S, Venkatraman <svenkatr@ti.com>
>> Signed-off-by: Manjunatha GK <manjugk@ti.com>
>> Signed-off-by: Govindraj R <govindraj.raja@ti.com>
>> ---
>>  arch/arm/plat-omap/dma.c              |   17 +++++++++++++++++
>>  arch/arm/plat-omap/include/plat/dma.h |    1 +
>>  2 files changed, 18 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
>> index 2ab224c..c73f11a 100644
>> --- a/arch/arm/plat-omap/dma.c
>> +++ b/arch/arm/plat-omap/dma.c
>> @@ -1109,6 +1109,23 @@ dma_addr_t omap_get_dma_dst_pos(int lch)
>>  }
>>  EXPORT_SYMBOL(omap_get_dma_dst_pos);
>>
>> +/**
>> + * omap_set_dma_dst_pos() - Set DMA channel destination address
>> + * @arg1:  lch      DMA logical channel number
>> + * @arg2:  value    Value to write into CDAC register
>> + *
>> + * Writes "value" into the register CPC/CDAC
>> + */
>> +void omap_set_dma_dst_pos(int lch, int value)
>> +{
>> +       if (cpu_is_omap15xx())
>> +               dma_write(value, CPC(lch));
>> +       else
>> +               dma_write(value, CDAC(lch));
>> +
>> +}
>> +EXPORT_SYMBOL(omap_set_dma_dst_pos);
>> +
>>  int omap_get_dma_active_status(int lch)
>>  {
>>        return (dma_read(CCR(lch)) & OMAP_DMA_CCR_EN) != 0;
>> diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h
>> index 02232ca..3b6e43e 100644
>> --- a/arch/arm/plat-omap/include/plat/dma.h
>> +++ b/arch/arm/plat-omap/include/plat/dma.h
>> @@ -509,6 +509,7 @@ extern int omap_set_dma_callback(int lch,
>>                        void *data);
>>  extern dma_addr_t omap_get_dma_src_pos(int lch);
>>  extern dma_addr_t omap_get_dma_dst_pos(int lch);
>> +extern void omap_set_dma_dst_pos(int lch, int value);
>>  extern void omap_clear_dma(int lch);
>>  extern int omap_get_dma_active_status(int lch);
>>  extern int omap_dma_running(void);
>> --
>  CDAC is not the destination address, as the API seems to suggest.
> CDSA (Channel Destination Start Address) is.
>
> CDAC is a running counter of the current transfer.
> I propose to update the omap_start_dma to reset CDAC to 0 always.

I agree with Venkat.  I think having it reset for every transfer
by default is the right way to handle this.

Kevin

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^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-03-02 17:16 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2010-03-02 13:36 [PATCH v2] OMAP: DMA: Add API for setting channel dest addr Manjunatha GK
2010-03-02 13:51 ` Venkatraman S
2010-03-02 17:16   ` Kevin Hilman

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