Re: [PATCH resend 2/2] dma: pl330: Use the common of_dma_xlate_by_chan_id

Re: [PATCH resend 2/2] dma: pl330: Use the common of_dma_xlate_by_chan_id

[PADMAVATHI VENNA]

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Hi Lars,

As I remember Vinod had asked you to keep DMA_CYCLIC capability on both controller and client side.  But I didn't see in this patch set. 
Otherwise your patches looks good to me.

Thanks
Padma
------- Original Message -------
Sender : Lars-Peter Clausen<lars@metafoo.de>
Date : May 13, 2013 01:02 (GMT+09:00)
Title : [PATCH resend 2/2] dma: pl330: Use the common 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.

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 a17553f..c831fae 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);
@@ -2989,7 +2950,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)

if (adev->dev.of_node) {
ret = of_dma_controller_register(adev->dev.of_node,
- of_dma_pl330_xlate, pdmac);
+ of_dma_pl330_xlate, pd);
if (ret) {
dev_err(&adev->dev,
"unable to register DMA to the generic DT DMA helpers\n");
-- 
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Re: [PATCH resend 2/2] dma: pl330: Use the common of_dma_xlate_by_chan_id

[Lars-Peter Clausen]

On 05/14/2013 10:53 AM, PADMAVATHI VENNA wrote:
> Hi Lars,
> 
> As I remember Vinod had asked you to keep DMA_CYCLIC capability on both controller and client side.  But I didn't see in this patch set. 

That doesn't make too much sense, since it means you'd only be able to
request channels for controllers which support cyclic transfers.

> Otherwise your patches looks good to me.
> 
> Thanks
> Padma
> ------- Original Message -------
> Sender : Lars-Peter Clausen<lars@metafoo.de>
> Date : May 13, 2013 01:02 (GMT+09:00)
> Title : [PATCH resend 2/2] dma: pl330: Use the common 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.
> 
> 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 a17553f..c831fae 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);
> @@ -2989,7 +2950,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
> 
> if (adev->dev.of_node) {
> ret = of_dma_controller_register(adev->dev.of_node,
> - of_dma_pl330_xlate, pdmac);
> + of_dma_pl330_xlate, pd);
> if (ret) {
> dev_err(&adev->dev,
> "unable to register DMA to the generic DT DMA helpers\n");

[PATCH resend 1/2] dma: of: Add common xlate function for matching by channel id

[Lars-Peter Clausen]

This patch adds a new common OF dma xlate callback function which will match a
channel by it's id. The binding expects one integer argument which it will use to
lookup the channel by the id.

Unlike of_dma_simple_xlate this function is able to handle a system with
multiple DMA controllers. When registering the of dma provider with
of_dma_controller_register a pointer to the dma_device struct which is
associated with the dt node needs to passed as the data parameter. The filter
function will use this pointer to match only channels which belong to the
specified DMA controller.

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 7aa0864..fa6f992 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -229,3 +229,50 @@ 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 wants
+ * 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 upon.
+ *
+ * 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 364dda7..b7cf614 100644
--- a/include/linux/of_dma.h
+++ b/include/linux/of_dma.h
@@ -42,6 +42,8 @@ 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)
@@ -67,6 +69,8 @@ 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

[PATCH resend 2/2] dma: pl330: Use the common of_dma_xlate_by_chan_id

[Lars-Peter Clausen]

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.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 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 a17553f..c831fae 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);
@@ -2989,7 +2950,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
 
 	if (adev->dev.of_node) {
 		ret = of_dma_controller_register(adev->dev.of_node,
-					 of_dma_pl330_xlate, pdmac);
+					 of_dma_pl330_xlate, pd);
 		if (ret) {
 			dev_err(&adev->dev,
 			"unable to register DMA to the generic DT DMA helpers\n");
-- 
1.8.0