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* Re: Re: [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id
@ 2013-04-02  9:12 PADMAVATHI VENNA
  2013-04-02 10:44 ` Lars-Peter Clausen
  0 siblings, 1 reply; 6+ messages in thread
From: PADMAVATHI VENNA @ 2013-04-02  9:12 UTC (permalink / raw)
  To: Lars-Peter Clausen
  Cc: Vinod Koul, Dan Williams, Jon Hunter,
	linux-kernel@vger.kernel.org

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Hi Lars,

------- Original Message -------
Sender : Lars-Peter Clausen<lars@metafoo.de>
Date : Apr 02, 2013 16:33 (GMT+09:00)
Title : Re: [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id

On 04/02/2013 08:27 AM, PADMAVATHI VENNA wrote:
> 
> Hi,
> ------- Original Message -------
> Sender : Lars-Peter Clausen
> Date : Mar 25, 2013 22:16 (GMT+09:00)
> Title : [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id
> 
> Use the generic of_dma_xlate_by_chan_id xlate callback instead of a custom
> implementation.
> 
> There is one minor difference between the generic of_dma_xlate_by_chan_id
> function and the pl330 specific one. of_dma_xlate_by_chan_id only sets the
> DMA_SLAVE capability for the channel capability mask, while the pl330 driver
> additionally sets the DMA_CYCLIC capability. But since all pl330 channels which
> have the DMA_SLAVE capability set also have DMA_CYCLIC capability set both
> functions will have the same result.
> 
> I am not clear about the dma capabilities. Is it mentioned some where that if we set DMA_SLAVE capability
> will that also set DMA_CYCLIC capability?
> 

Well DMA_SLAVE won't automatically set DMA_CYCLIC. But the driver sets both.

I tested your patches, it's woking for audio. But I need some clarification related to capabilities.
As per my understanding, controller driver registers the available capabilities in the probe and 
client drivers requests for a particular capability. In both the cases, in the dmaengine it checks
if the requested capability is satisfied.
If we don't set the DMA_CYCLIC, how __dma_device_satisfies_mask works?

 Please correct me if I am wrong.

Thanks
Padma
- Lars

> Signed-off-by: Lars-Peter Clausen 
> ---
> drivers/dma/pl330.c | 41 +----------------------------------------
> 1 file changed, 1 insertion(+), 40 deletions(-)
> 
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 345e2a1..ea48de7 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -608,11 +608,6 @@ struct dma_pl330_desc {
> struct dma_pl330_chan *pchan;
> };
> 
> -struct dma_pl330_filter_args {
> - struct dma_pl330_dmac *pdmac;
> - unsigned int chan_id;
> -};
> -
> static inline void _callback(struct pl330_req *r, enum pl330_op_err err)
> {
> if (r && r->xfer_cb)
> @@ -2358,16 +2353,6 @@ static void dma_pl330_rqcb(void *token, enum pl330_op_err err)
> tasklet_schedule(&pch->task);
> }
> 
> -static bool pl330_dt_filter(struct dma_chan *chan, void *param)
> -{
> - struct dma_pl330_filter_args *fargs = param;
> -
> - if (chan->device != &fargs->pdmac->ddma)
> - return false;
> -
> - return (chan->chan_id == fargs->chan_id);
> -}
> -
> bool pl330_filter(struct dma_chan *chan, void *param)
> {
> u8 *peri_id;
> @@ -2380,30 +2365,6 @@ bool pl330_filter(struct dma_chan *chan, void *param)
> }
> EXPORT_SYMBOL(pl330_filter);
> 
> -static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,
> - struct of_dma *ofdma)
> -{
> - int count = dma_spec->args_count;
> - struct dma_pl330_dmac *pdmac = ofdma->of_dma_data;
> - struct dma_pl330_filter_args fargs;
> - dma_cap_mask_t cap;
> -
> - if (!pdmac)
> - return NULL;
> -
> - if (count != 1)
> - return NULL;
> -
> - fargs.pdmac = pdmac;
> - fargs.chan_id = dma_spec->args[0];
> -
> - dma_cap_zero(cap);
> - dma_cap_set(DMA_SLAVE, cap);
> - dma_cap_set(DMA_CYCLIC, cap);
> -
> - return dma_request_channel(cap, pl330_dt_filter, &fargs);
> -}
> -
> static int pl330_alloc_chan_resources(struct dma_chan *chan)
> {
> struct dma_pl330_chan *pch = to_pchan(chan);
> @@ -2996,7 +2957,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
> pi->pcfg.num_peri, pi->pcfg.num_events);
> 
> ret = of_dma_controller_register(adev->dev.of_node,
> - of_dma_pl330_xlate, pdmac);
> + of_dma_xlate_by_chan_id, pd);
> if (ret) {
> dev_err(&adev->dev,
> "unable to register DMA to the generic DT DMA helpers\n");ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id
@ 2013-04-02  6:27 PADMAVATHI VENNA
  2013-04-02  7:33 ` Lars-Peter Clausen
  0 siblings, 1 reply; 6+ messages in thread
From: PADMAVATHI VENNA @ 2013-04-02  6:27 UTC (permalink / raw)
  To: Lars-Peter Clausen, Vinod Koul, Dan Williams
  Cc: Jon Hunter, linux-kernel@vger.kernel.org

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Hi,
------- Original Message -------
Sender : Lars-Peter Clausen<lars@metafoo.de>
Date : Mar 25, 2013 22:16 (GMT+09:00)
Title : [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id

Use the generic of_dma_xlate_by_chan_id xlate callback instead of a custom
implementation.

There is one minor difference between the generic of_dma_xlate_by_chan_id
function and the pl330 specific one. of_dma_xlate_by_chan_id only sets the
DMA_SLAVE capability for the channel capability mask, while the pl330 driver
additionally sets the DMA_CYCLIC capability. But since all pl330 channels which
have the DMA_SLAVE capability set also have DMA_CYCLIC capability set both
functions will have the same result.

I am not clear about the dma capabilities. Is it mentioned some where that if we set DMA_SLAVE capability
will that also set DMA_CYCLIC capability?

Signed-off-by: Lars-Peter Clausen 
---
drivers/dma/pl330.c | 41 +----------------------------------------
1 file changed, 1 insertion(+), 40 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 345e2a1..ea48de7 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -608,11 +608,6 @@ struct dma_pl330_desc {
struct dma_pl330_chan *pchan;
};

-struct dma_pl330_filter_args {
- struct dma_pl330_dmac *pdmac;
- unsigned int chan_id;
-};
-
static inline void _callback(struct pl330_req *r, enum pl330_op_err err)
{
if (r && r->xfer_cb)
@@ -2358,16 +2353,6 @@ static void dma_pl330_rqcb(void *token, enum pl330_op_err err)
tasklet_schedule(&pch->task);
}

-static bool pl330_dt_filter(struct dma_chan *chan, void *param)
-{
- struct dma_pl330_filter_args *fargs = param;
-
- if (chan->device != &fargs->pdmac->ddma)
- return false;
-
- return (chan->chan_id == fargs->chan_id);
-}
-
bool pl330_filter(struct dma_chan *chan, void *param)
{
u8 *peri_id;
@@ -2380,30 +2365,6 @@ bool pl330_filter(struct dma_chan *chan, void *param)
}
EXPORT_SYMBOL(pl330_filter);

-static struct dma_chan *of_dma_pl330_xlate(struct of_phandle_args *dma_spec,
- struct of_dma *ofdma)
-{
- int count = dma_spec->args_count;
- struct dma_pl330_dmac *pdmac = ofdma->of_dma_data;
- struct dma_pl330_filter_args fargs;
- dma_cap_mask_t cap;
-
- if (!pdmac)
- return NULL;
-
- if (count != 1)
- return NULL;
-
- fargs.pdmac = pdmac;
- fargs.chan_id = dma_spec->args[0];
-
- dma_cap_zero(cap);
- dma_cap_set(DMA_SLAVE, cap);
- dma_cap_set(DMA_CYCLIC, cap);
-
- return dma_request_channel(cap, pl330_dt_filter, &fargs);
-}
-
static int pl330_alloc_chan_resources(struct dma_chan *chan)
{
struct dma_pl330_chan *pch = to_pchan(chan);
@@ -2996,7 +2957,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
pi->pcfg.num_peri, pi->pcfg.num_events);

ret = of_dma_controller_register(adev->dev.of_node,
- of_dma_pl330_xlate, pdmac);
+ of_dma_xlate_by_chan_id, pd);
if (ret) {
dev_err(&adev->dev,
"unable to register DMA to the generic DT DMA helpers\n");
-- 
1.8.0ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 1/2] dma: of: Add generic xlate function for matching by channel id
@ 2013-03-25 13:16 Lars-Peter Clausen
  2013-03-25 13:16 ` [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id Lars-Peter Clausen
  0 siblings, 1 reply; 6+ messages in thread
From: Lars-Peter Clausen @ 2013-03-25 13:16 UTC (permalink / raw)
  To: Vinod Koul, Dan Williams
  Cc: Jon Hunter, Padmavathi Venna, linux-kernel, Lars-Peter Clausen

This patch adds a new generic of dma xlate callback function which will match a
channel by its id.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/dma/of-dma.c   | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of_dma.h |  4 ++++
 2 files changed, 51 insertions(+)

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 00db454..7cad4d7 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -269,3 +269,50 @@ struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 			&dma_spec->args[0]);
 }
 EXPORT_SYMBOL_GPL(of_dma_simple_xlate);
+
+struct of_dma_filter_by_chan_id_args {
+	struct dma_device *dev;
+	unsigned int chan_id;
+};
+
+static bool of_dma_filter_by_chan_id(struct dma_chan *chan, void *params)
+{
+	struct of_dma_filter_by_chan_id_args *args = params;
+
+	return chan->device == args->dev && chan->chan_id == args->chan_id;
+}
+
+/**
+ * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id
+ * @dma_spec:	pointer to DMA specifier as found in the device tree
+ * @of_dma:	pointer to DMA controller data
+ *
+ * This function can be used as the of xlate callback for DMA driver which want
+ * to match the channel based on the channel id. When using this xlate function
+ * the #dma-cells propety of the DMA controller dt node needs to be set to 1.
+ * The data parameter of of_dma_controller_register must be a pointer to the
+ * dma_device struct the function should match uppon.
+ *
+ * Returns pointer to appropriate dma channel on success or NULL on error.
+ */
+struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	struct of_dma_filter_by_chan_id_args args;
+	dma_cap_mask_t cap;
+
+	args.dev = ofdma->of_dma_data;
+	if (!args.dev)
+		return NULL;
+
+	if (dma_spec->args_count != 1)
+		return NULL;
+
+	dma_cap_zero(cap);
+	dma_cap_set(DMA_SLAVE, cap);
+
+	args.chan_id = dma_spec->args[0];
+
+	return dma_request_channel(cap, of_dma_filter_by_chan_id, &args);
+}
+EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id);
diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h
index ce6a8ab..46732d3 100644
--- a/include/linux/of_dma.h
+++ b/include/linux/of_dma.h
@@ -43,6 +43,8 @@ extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 						     const char *name);
 extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 		struct of_dma *ofdma);
+extern struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
+		struct of_dma *ofdma);
 #else
 static inline int of_dma_controller_register(struct device_node *np,
 		struct dma_chan *(*of_dma_xlate)
@@ -69,6 +71,8 @@ static inline struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_s
 	return NULL;
 }
 
+#define of_dma_xlate_by_chan_id NULL
+
 #endif
 
 #endif /* __LINUX_OF_DMA_H */
-- 
1.8.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-04-02 18:01 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2013-04-02  9:12 Re: [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id PADMAVATHI VENNA
2013-04-02 10:44 ` Lars-Peter Clausen
2013-04-02 17:33   ` Vinod Koul
  -- strict thread matches above, loose matches on Subject: below --
2013-04-02  6:27 PADMAVATHI VENNA
2013-04-02  7:33 ` Lars-Peter Clausen
2013-03-25 13:16 [PATCH 1/2] dma: of: Add generic xlate function for matching by channel id Lars-Peter Clausen
2013-03-25 13:16 ` [PATCH 2/2] dma: pl330: Use the generic of_dma_xlate_by_chan_id Lars-Peter Clausen

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