[PATCH] dmaengine: at_hdmac: add device tree probe

[PATCH] dmaengine: at_hdmac: add device tree probe

[Nicolas Ferre]

Add device tree probe support for atmel at_hdmac DMA driver.
Bindings are added to specify the number of channels that the implementation of
the controller actually has. They also allow to tell if the peripherals/DMA
transfer is supported by the IP.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 .../devicetree/bindings/dma/atmel-hdmac.txt        |   23 +++++++++
 drivers/dma/at_hdmac.c                             |   51 ++++++++++++++++----
 2 files changed, 65 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/atmel-hdmac.txt

diff --git a/Documentation/devicetree/bindings/dma/atmel-hdmac.txt b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
new file mode 100644
index 0000000..0e48553
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
@@ -0,0 +1,23 @@
+* Atmel Direct Memory Access Controller
+
+Required properties:
+- compatible: Should be "atmel,<chip>-hdmac"
+- reg: Should contain DMA registers location and length
+- interrupts: Should contain DMA interrupt
+- atmel,hdmac-nr-channels: Should contain number of channels
+  available in the controller
+
+Optional properties:
+- atmel,hdmac-cap-memcpy: Chip can do memory to memory transfers
+- atmel,hdmac-cap-slave: Chip can do peripherals/memory transfers
+
+Examples:
+
+dma@ffffec00 {
+	compatible = "atmel,at91sam9g45-hdmac";
+	reg = <0xffffec00 0x200>;
+	interrupts = <21>;
+	atmel,hdmac-nr-channels = <8>;
+	atmel,hdmac-cap-memcpy;
+	atmel,hdmac-cap-slave;
+};
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 8f1d2ee..4a0cefe 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -23,6 +23,8 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include "at_hdmac_regs.h"
 
@@ -1167,6 +1169,18 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 
 /*--  Module Management  -----------------------------------------------*/
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_dma_dt_ids[] = {
+	{ .compatible = "atmel,at91sam9rl-hdmac" },
+	{ .compatible = "atmel,at91sam9g45-hdmac" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
+#else
+#define atmel_dma_dt_ids NULL
+#endif
+
 /**
  * at_dma_off - disable DMA controller
  * @atdma: the Atmel HDAMC device
@@ -1185,17 +1199,36 @@ static void at_dma_off(struct at_dma *atdma)
 
 static int __init at_dma_probe(struct platform_device *pdev)
 {
-	struct at_dma_platform_data *pdata;
+	const struct of_device_id *of_id =
+			of_match_device(atmel_dma_dt_ids, &pdev->dev);
+	struct device_node	*np = pdev->dev.of_node;
+	struct at_dma_platform_data *pdata = pdev->dev.platform_data;
 	struct resource		*io;
 	struct at_dma		*atdma;
 	size_t			size;
 	int			irq;
 	int			err;
 	int			i;
+	u32			nr_channels;
+	dma_cap_mask_t		cap_mask = {};
+
+	/* get DMA Controller parameters */
+	if (of_id) {
+		if (of_property_read_u32(np, "atmel,hdmac-nr-channels",
+					&nr_channels))
+			return -EINVAL;
+		if (of_find_property(np, "atmel,hdmac-cap-memcpy", NULL))
+			dma_cap_set(DMA_MEMCPY, cap_mask);
+		if (of_find_property(np, "atmel,hdmac-cap-slave", NULL))
+			dma_cap_set(DMA_SLAVE, cap_mask);
+	} else if (pdata) {
+		nr_channels = pdata->nr_channels;
+		cap_mask = pdata->cap_mask;
+	} else {
+		return -EINVAL;
+	}
 
-	/* get DMA Controller parameters from platform */
-	pdata = pdev->dev.platform_data;
-	if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
+	if (!nr_channels || nr_channels > AT_DMA_MAX_NR_CHANNELS)
 		return -EINVAL;
 
 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1207,14 +1240,13 @@ static int __init at_dma_probe(struct platform_device *pdev)
 		return irq;
 
 	size = sizeof(struct at_dma);
-	size += pdata->nr_channels * sizeof(struct at_dma_chan);
+	size += nr_channels * sizeof(struct at_dma_chan);
 	atdma = kzalloc(size, GFP_KERNEL);
 	if (!atdma)
 		return -ENOMEM;
 
-	/* discover transaction capabilites from the platform data */
-	atdma->dma_common.cap_mask = pdata->cap_mask;
-	atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
+	atdma->dma_common.cap_mask = cap_mask;
+	atdma->all_chan_mask = (1 << nr_channels) - 1;
 
 	size = io->end - io->start + 1;
 	if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
@@ -1260,7 +1292,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	/* initialize channels related values */
 	INIT_LIST_HEAD(&atdma->dma_common.channels);
-	for (i = 0; i < pdata->nr_channels; i++, atdma->dma_common.chancnt++) {
+	for (i = 0; i < nr_channels; i++, atdma->dma_common.chancnt++) {
 		struct at_dma_chan	*atchan = &atdma->chan[i];
 
 		atchan->chan_common.device = &atdma->dma_common;
@@ -1406,6 +1438,7 @@ static struct platform_driver at_dma_driver = {
 	.driver = {
 		.name	= "at_hdmac",
 		.pm	= &at_dma_dev_pm_ops,
+		.of_match_table	= atmel_dma_dt_ids,
 	},
 };
 
-- 
1.7.4.1

Re: [PATCH] dmaengine: at_hdmac: add device tree probe

[Grant Likely]

On Fri, Aug 05, 2011 at 01:58:40PM +0100, Nicolas Ferre wrote:
> Add device tree probe support for atmel at_hdmac DMA driver.
> Bindings are added to specify the number of channels that the implementation of
> the controller actually has. They also allow to tell if the peripherals/DMA
> transfer is supported by the IP.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  .../devicetree/bindings/dma/atmel-hdmac.txt        |   23 +++++++++
>  drivers/dma/at_hdmac.c                             |   51 ++++++++++++++++----
>  2 files changed, 65 insertions(+), 9 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/dma/atmel-hdmac.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/atmel-hdmac.txt b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
> new file mode 100644
> index 0000000..0e48553
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
> @@ -0,0 +1,23 @@
> +* Atmel Direct Memory Access Controller
> +
> +Required properties:
> +- compatible: Should be "atmel,<chip>-hdmac"
> +- reg: Should contain DMA registers location and length
> +- interrupts: Should contain DMA interrupt
> +- atmel,hdmac-nr-channels: Should contain number of channels
> +  available in the controller
> +
> +Optional properties:
> +- atmel,hdmac-cap-memcpy: Chip can do memory to memory transfers
> +- atmel,hdmac-cap-slave: Chip can do peripherals/memory transfers

Heh, ignore my comments on the other patch about missing documentation
for the dma engine.  :-)

Otherwise the patch looks pretty good.  I suspect there is a thing or
two that won't compile correctly when !CONFIG_OF, but I haven't
checked closely.  Just make sure !CONFIG_OF is tested.  :-)

g.


> +
> +Examples:
> +
> +dma@ffffec00 {
> +	compatible = "atmel,at91sam9g45-hdmac";
> +	reg = <0xffffec00 0x200>;
> +	interrupts = <21>;
> +	atmel,hdmac-nr-channels = <8>;
> +	atmel,hdmac-cap-memcpy;
> +	atmel,hdmac-cap-slave;
> +};
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 8f1d2ee..4a0cefe 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -23,6 +23,8 @@
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
>  
>  #include "at_hdmac_regs.h"
>  
> @@ -1167,6 +1169,18 @@ static void atc_free_chan_resources(struct dma_chan *chan)
>  
>  /*--  Module Management  -----------------------------------------------*/
>  
> +#if defined(CONFIG_OF)
> +static const struct of_device_id atmel_dma_dt_ids[] = {
> +	{ .compatible = "atmel,at91sam9rl-hdmac" },
> +	{ .compatible = "atmel,at91sam9g45-hdmac" },
> +	{ /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
> +#else
> +#define atmel_dma_dt_ids NULL
> +#endif
> +
>  /**
>   * at_dma_off - disable DMA controller
>   * @atdma: the Atmel HDAMC device
> @@ -1185,17 +1199,36 @@ static void at_dma_off(struct at_dma *atdma)
>  
>  static int __init at_dma_probe(struct platform_device *pdev)
>  {
> -	struct at_dma_platform_data *pdata;
> +	const struct of_device_id *of_id =
> +			of_match_device(atmel_dma_dt_ids, &pdev->dev);
> +	struct device_node	*np = pdev->dev.of_node;
> +	struct at_dma_platform_data *pdata = pdev->dev.platform_data;
>  	struct resource		*io;
>  	struct at_dma		*atdma;
>  	size_t			size;
>  	int			irq;
>  	int			err;
>  	int			i;
> +	u32			nr_channels;
> +	dma_cap_mask_t		cap_mask = {};
> +
> +	/* get DMA Controller parameters */
> +	if (of_id) {
> +		if (of_property_read_u32(np, "atmel,hdmac-nr-channels",
> +					&nr_channels))
> +			return -EINVAL;
> +		if (of_find_property(np, "atmel,hdmac-cap-memcpy", NULL))
> +			dma_cap_set(DMA_MEMCPY, cap_mask);
> +		if (of_find_property(np, "atmel,hdmac-cap-slave", NULL))
> +			dma_cap_set(DMA_SLAVE, cap_mask);
> +	} else if (pdata) {
> +		nr_channels = pdata->nr_channels;
> +		cap_mask = pdata->cap_mask;
> +	} else {
> +		return -EINVAL;
> +	}
>  
> -	/* get DMA Controller parameters from platform */
> -	pdata = pdev->dev.platform_data;
> -	if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
> +	if (!nr_channels || nr_channels > AT_DMA_MAX_NR_CHANNELS)
>  		return -EINVAL;
>  
>  	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -1207,14 +1240,13 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  		return irq;
>  
>  	size = sizeof(struct at_dma);
> -	size += pdata->nr_channels * sizeof(struct at_dma_chan);
> +	size += nr_channels * sizeof(struct at_dma_chan);
>  	atdma = kzalloc(size, GFP_KERNEL);
>  	if (!atdma)
>  		return -ENOMEM;
>  
> -	/* discover transaction capabilites from the platform data */
> -	atdma->dma_common.cap_mask = pdata->cap_mask;
> -	atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
> +	atdma->dma_common.cap_mask = cap_mask;
> +	atdma->all_chan_mask = (1 << nr_channels) - 1;
>  
>  	size = io->end - io->start + 1;
>  	if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
> @@ -1260,7 +1292,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  
>  	/* initialize channels related values */
>  	INIT_LIST_HEAD(&atdma->dma_common.channels);
> -	for (i = 0; i < pdata->nr_channels; i++, atdma->dma_common.chancnt++) {
> +	for (i = 0; i < nr_channels; i++, atdma->dma_common.chancnt++) {
>  		struct at_dma_chan	*atchan = &atdma->chan[i];
>  
>  		atchan->chan_common.device = &atdma->dma_common;
> @@ -1406,6 +1438,7 @@ static struct platform_driver at_dma_driver = {
>  	.driver = {
>  		.name	= "at_hdmac",
>  		.pm	= &at_dma_dev_pm_ops,
> +		.of_match_table	= atmel_dma_dt_ids,
>  	},
>  };
>  
> -- 
> 1.7.4.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] dmaengine: at_hdmac: add device tree probe

[Nicolas Ferre]

Le 07/08/2011 06:09, Grant Likely :
> On Fri, Aug 05, 2011 at 01:58:40PM +0100, Nicolas Ferre wrote:
>> Add device tree probe support for atmel at_hdmac DMA driver.
>> Bindings are added to specify the number of channels that the implementation of
>> the controller actually has. They also allow to tell if the peripherals/DMA
>> transfer is supported by the IP.
>>
>> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
>> ---
>>  .../devicetree/bindings/dma/atmel-hdmac.txt        |   23 +++++++++
>>  drivers/dma/at_hdmac.c                             |   51 ++++++++++++++++----
>>  2 files changed, 65 insertions(+), 9 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/dma/atmel-hdmac.txt
>>
>> diff --git a/Documentation/devicetree/bindings/dma/atmel-hdmac.txt b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
>> new file mode 100644
>> index 0000000..0e48553
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/dma/atmel-hdmac.txt
>> @@ -0,0 +1,23 @@
>> +* Atmel Direct Memory Access Controller
>> +
>> +Required properties:
>> +- compatible: Should be "atmel,<chip>-hdmac"
>> +- reg: Should contain DMA registers location and length
>> +- interrupts: Should contain DMA interrupt
>> +- atmel,hdmac-nr-channels: Should contain number of channels
>> +  available in the controller
>> +
>> +Optional properties:
>> +- atmel,hdmac-cap-memcpy: Chip can do memory to memory transfers
>> +- atmel,hdmac-cap-slave: Chip can do peripherals/memory transfers
> 
> Heh, ignore my comments on the other patch about missing documentation
> for the dma engine.  :-)
> 
> Otherwise the patch looks pretty good.

[..]

Grant, Vinod,

Don't you think it would make sense to generalize nr-channels and maybe
also the capabilities properties for other dmaengine drivers?
I have seen other dmaengine drivers taking the number of channels from
platform data so that would make sense.
It would be new dmaengine device tree properties, but on the other hand,
I do not know if code can also be centralized for handling of those
properties... maybe it is better to let drivers deal with them if
required...

Your thoughts?

Best regards,
-- 
Nicolas Ferre

Re: [PATCH] dmaengine: at_hdmac: add device tree probe

[Koul, Vinod]

On Tue, 2011-08-16 at 18:33 +0200, Nicolas Ferre wrote:
> [..]
> 
> Grant, Vinod,
> 
> Don't you think it would make sense to generalize nr-channels and maybe
> also the capabilities properties for other dmaengine drivers?
> I have seen other dmaengine drivers taking the number of channels from
> platform data so that would make sense.
> It would be new dmaengine device tree properties, but on the other hand,
> I do not know if code can also be centralized for handling of those
> properties... maybe it is better to let drivers deal with them if
> required...
> 
We already having this discussion and how to change capabilities etc to
make thing more easy and transparent, See the approaches taken by Jassi
and Linus W

-- 
~Vinod

[PATCH 1/4] dmaengine: at_hdmac: platform data move to use .id_table

[Nicolas Ferre]

We remove platform data from DMA controller and move
to the use of .id_table to distinguish between compatible
types. The two implementations allow to determine the
number of channels and the capabilities of the controller.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/dma/at_hdmac.c      |   48 ++++++++++++++++++++++++++++++++++---------
 drivers/dma/at_hdmac_regs.h |    8 +++++++
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index fcfa0a8..fef57bc 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1175,6 +1175,18 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 
 /*--  Module Management  -----------------------------------------------*/
 
+static struct platform_device_id atdma_devtypes[] = {
+	{
+		.name = "at91sam9rl_dma",
+		.driver_data = ATDMA_DEVTYPE_SAM9RL,
+	}, {
+		.name = "at91sam9g45_dma",
+		.driver_data = ATDMA_DEVTYPE_SAM9G45,
+	}, {
+		/* sentinel */
+	}
+};
+
 /**
  * at_dma_off - disable DMA controller
  * @atdma: the Atmel HDAMC device
@@ -1193,18 +1205,32 @@ static void at_dma_off(struct at_dma *atdma)
 
 static int __init at_dma_probe(struct platform_device *pdev)
 {
-	struct at_dma_platform_data *pdata;
 	struct resource		*io;
 	struct at_dma		*atdma;
 	size_t			size;
 	int			irq;
 	int			err;
 	int			i;
+	u32                     nr_channels;
+	dma_cap_mask_t          cap_mask = {};
+	enum atdma_devtype	atdmatype;
+
+	dma_cap_set(DMA_MEMCPY, cap_mask);
+
+	/* get DMA parameters from controller type */
+	atdmatype = platform_get_device_id(pdev)->driver_data;
 
-	/* get DMA Controller parameters from platform */
-	pdata = pdev->dev.platform_data;
-	if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
+	switch (atdmatype) {
+	case ATDMA_DEVTYPE_SAM9RL:
+		nr_channels = 2;
+		break;
+	case ATDMA_DEVTYPE_SAM9G45:
+		nr_channels = 8;
+		dma_cap_set(DMA_SLAVE, cap_mask);
+		break;
+	default:
 		return -EINVAL;
+	}
 
 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!io)
@@ -1215,14 +1241,15 @@ static int __init at_dma_probe(struct platform_device *pdev)
 		return irq;
 
 	size = sizeof(struct at_dma);
-	size += pdata->nr_channels * sizeof(struct at_dma_chan);
+	size += nr_channels * sizeof(struct at_dma_chan);
 	atdma = kzalloc(size, GFP_KERNEL);
 	if (!atdma)
 		return -ENOMEM;
 
-	/* discover transaction capabilites from the platform data */
-	atdma->dma_common.cap_mask = pdata->cap_mask;
-	atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
+	/* discover transaction capabilites */
+	atdma->dma_common.cap_mask = cap_mask;
+	atdma->all_chan_mask = (1 << nr_channels) - 1;
+	atdma->devtype = atdmatype;
 
 	size = resource_size(io);
 	if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
@@ -1268,7 +1295,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	/* initialize channels related values */
 	INIT_LIST_HEAD(&atdma->dma_common.channels);
-	for (i = 0; i < pdata->nr_channels; i++) {
+	for (i = 0; i < nr_channels; i++) {
 		struct at_dma_chan	*atchan = &atdma->chan[i];
 
 		atchan->chan_common.device = &atdma->dma_common;
@@ -1313,7 +1340,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
 	  dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
 	  dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",
-	  pdata->nr_channels);
+	  nr_channels);
 
 	dma_async_device_register(&atdma->dma_common);
 
@@ -1495,6 +1522,7 @@ static const struct dev_pm_ops at_dma_dev_pm_ops = {
 static struct platform_driver at_dma_driver = {
 	.remove		= __exit_p(at_dma_remove),
 	.shutdown	= at_dma_shutdown,
+	.id_table	= atdma_devtypes,
 	.driver = {
 		.name	= "at_hdmac",
 		.pm	= &at_dma_dev_pm_ops,
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index aa4c9ae..d7d6737 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -248,9 +248,16 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
 
 /*--  Controller  ------------------------------------------------------*/
 
+enum atdma_devtype {
+	ATDMA_DEVTYPE_UNDEFINED = 0,
+	ATDMA_DEVTYPE_SAM9RL,	/* compatible with SAM9RL DMA controller */
+	ATDMA_DEVTYPE_SAM9G45,	/* compatible with SAM9G45 DMA controller */
+};
+
 /**
  * struct at_dma - internal representation of an Atmel HDMA Controller
  * @chan_common: common dmaengine dma_device object members
+ * @atdma_devtype: identifier of DMA controller compatibility
  * @ch_regs: memory mapped register base
  * @clk: dma controller clock
  * @save_imr: interrupt mask register that is saved on suspend/resume cycle
@@ -260,6 +267,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
  */
 struct at_dma {
 	struct dma_device	dma_common;
+	enum atdma_devtype	devtype;
 	void __iomem		*regs;
 	struct clk		*clk;
 	u32			save_imr;
-- 
1.7.5.4

[PATCH 2/4] dmaengine: at_hdmac: add device tree support

[Nicolas Ferre]

Add device tree probe support for atmel at_hdmac DMA driver.
Bindings are added to specify DMA controller configuration.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 .../devicetree/bindings/dma/atmel-dma.txt          |   14 +++++++++
 drivers/dma/at_hdmac.c                             |   30 +++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/atmel-dma.txt

diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt
new file mode 100644
index 0000000..3c046ee
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt
@@ -0,0 +1,14 @@
+* Atmel Direct Memory Access Controller (DMA)
+
+Required properties:
+- compatible: Should be "atmel,<chip>-dma"
+- reg: Should contain DMA registers location and length
+- interrupts: Should contain DMA interrupt
+
+Examples:
+
+dma@ffffec00 {
+	compatible = "atmel,at91sam9g45-dma";
+	reg = <0xffffec00 0x200>;
+	interrupts = <21>;
+};
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index fef57bc..6d25b6a 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -23,6 +23,8 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include "at_hdmac_regs.h"
 
@@ -1175,6 +1177,20 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 
 /*--  Module Management  -----------------------------------------------*/
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_dma_dt_ids[] = {
+	{
+		.compatible = "atmel,at91sam9rl-dma",
+		.data = (void *)ATDMA_DEVTYPE_SAM9RL
+	}, {
+		.compatible = "atmel,at91sam9g45-dma",
+		.data = (void *)ATDMA_DEVTYPE_SAM9G45
+	}, { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
+#endif
+
 static struct platform_device_id atdma_devtypes[] = {
 	{
 		.name = "at91sam9rl_dma",
@@ -1187,6 +1203,17 @@ static struct platform_device_id atdma_devtypes[] = {
 	}
 };
 
+static inline enum atdma_devtype __init at_dma_get_driver_data(
+					struct platform_device *pdev)
+{
+	if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
+		return (enum atdma_devtype)match->data;
+	}
+	return platform_get_device_id(pdev)->driver_data;
+}
+
 /**
  * at_dma_off - disable DMA controller
  * @atdma: the Atmel HDAMC device
@@ -1218,7 +1245,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 	dma_cap_set(DMA_MEMCPY, cap_mask);
 
 	/* get DMA parameters from controller type */
-	atdmatype = platform_get_device_id(pdev)->driver_data;
+	atdmatype = at_dma_get_driver_data(pdev);
 
 	switch (atdmatype) {
 	case ATDMA_DEVTYPE_SAM9RL:
@@ -1526,6 +1553,7 @@ static struct platform_driver at_dma_driver = {
 	.driver = {
 		.name	= "at_hdmac",
 		.pm	= &at_dma_dev_pm_ops,
+		.of_match_table	= of_match_ptr(atmel_dma_dt_ids),
 	},
 };
 
-- 
1.7.5.4

[PATCH 3/4] ARM: at91/dma: remove platform data from DMA controller

[Nicolas Ferre]

DMA controller can deduce its configuration data from
the platform. Remove the platform data and match device
types with the compatible ones.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9g45_devices.c |    9 +--------
 arch/arm/mach-at91/at91sam9rl_devices.c  |    8 +-------
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 600bffb..c9b897f 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -38,10 +38,6 @@
 #if defined(CONFIG_AT_HDMAC) || defined(CONFIG_AT_HDMAC_MODULE)
 static u64 hdmac_dmamask = DMA_BIT_MASK(32);
 
-static struct at_dma_platform_data atdma_pdata = {
-	.nr_channels	= 8,
-};
-
 static struct resource hdmac_resources[] = {
 	[0] = {
 		.start	= AT91_BASE_SYS + AT91_DMA,
@@ -56,12 +52,11 @@ static struct resource hdmac_resources[] = {
 };
 
 static struct platform_device at_hdmac_device = {
-	.name		= "at_hdmac",
+	.name		= "at91sam9g45_dma",
 	.id		= -1,
 	.dev		= {
 				.dma_mask		= &hdmac_dmamask,
 				.coherent_dma_mask	= DMA_BIT_MASK(32),
-				.platform_data		= &atdma_pdata,
 	},
 	.resource	= hdmac_resources,
 	.num_resources	= ARRAY_SIZE(hdmac_resources),
@@ -69,8 +64,6 @@ static struct platform_device at_hdmac_device = {
 
 void __init at91_add_device_hdmac(void)
 {
-	dma_cap_set(DMA_MEMCPY, atdma_pdata.cap_mask);
-	dma_cap_set(DMA_SLAVE, atdma_pdata.cap_mask);
 	platform_device_register(&at_hdmac_device);
 }
 #else
diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
index aacb19d..81954f7 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -33,10 +33,6 @@
 #if defined(CONFIG_AT_HDMAC) || defined(CONFIG_AT_HDMAC_MODULE)
 static u64 hdmac_dmamask = DMA_BIT_MASK(32);
 
-static struct at_dma_platform_data atdma_pdata = {
-	.nr_channels	= 2,
-};
-
 static struct resource hdmac_resources[] = {
 	[0] = {
 		.start	= AT91_BASE_SYS + AT91_DMA,
@@ -51,12 +47,11 @@ static struct resource hdmac_resources[] = {
 };
 
 static struct platform_device at_hdmac_device = {
-	.name		= "at_hdmac",
+	.name		= "at91sam9rl_dma",
 	.id		= -1,
 	.dev		= {
 				.dma_mask		= &hdmac_dmamask,
 				.coherent_dma_mask	= DMA_BIT_MASK(32),
-				.platform_data		= &atdma_pdata,
 	},
 	.resource	= hdmac_resources,
 	.num_resources	= ARRAY_SIZE(hdmac_resources),
@@ -64,7 +59,6 @@ static struct platform_device at_hdmac_device = {
 
 void __init at91_add_device_hdmac(void)
 {
-	dma_cap_set(DMA_MEMCPY, atdma_pdata.cap_mask);
 	platform_device_register(&at_hdmac_device);
 }
 #else
-- 
1.7.5.4

Re: [PATCH 3/4] ARM: at91/dma: remove platform data from DMA controller

[Vinod Koul]

On Mon, 2011-10-10 at 18:37 +0200, Nicolas Ferre wrote:
> DMA controller can deduce its configuration data from
> the platform. Remove the platform data and match device
> types with the compatible ones.
This looks like remove, you should fix the changelog of patch 1 then.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  arch/arm/mach-at91/at91sam9g45_devices.c |    9 +--------
>  arch/arm/mach-at91/at91sam9rl_devices.c  |    8 +-------
>  2 files changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
> index 600bffb..c9b897f 100644
> --- a/arch/arm/mach-at91/at91sam9g45_devices.c
> +++ b/arch/arm/mach-at91/at91sam9g45_devices.c
> @@ -38,10 +38,6 @@
>  #if defined(CONFIG_AT_HDMAC) || defined(CONFIG_AT_HDMAC_MODULE)
>  static u64 hdmac_dmamask = DMA_BIT_MASK(32);
>  
> -static struct at_dma_platform_data atdma_pdata = {
> -	.nr_channels	= 8,
> -};
> -
>  static struct resource hdmac_resources[] = {
>  	[0] = {
>  		.start	= AT91_BASE_SYS + AT91_DMA,
> @@ -56,12 +52,11 @@ static struct resource hdmac_resources[] = {
>  };
>  
>  static struct platform_device at_hdmac_device = {
> -	.name		= "at_hdmac",
> +	.name		= "at91sam9g45_dma",
>  	.id		= -1,
>  	.dev		= {
>  				.dma_mask		= &hdmac_dmamask,
>  				.coherent_dma_mask	= DMA_BIT_MASK(32),
> -				.platform_data		= &atdma_pdata,
>  	},
>  	.resource	= hdmac_resources,
>  	.num_resources	= ARRAY_SIZE(hdmac_resources),
> @@ -69,8 +64,6 @@ static struct platform_device at_hdmac_device = {
>  
>  void __init at91_add_device_hdmac(void)
>  {
> -	dma_cap_set(DMA_MEMCPY, atdma_pdata.cap_mask);
> -	dma_cap_set(DMA_SLAVE, atdma_pdata.cap_mask);
>  	platform_device_register(&at_hdmac_device);
>  }
>  #else
> diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
> index aacb19d..81954f7 100644
> --- a/arch/arm/mach-at91/at91sam9rl_devices.c
> +++ b/arch/arm/mach-at91/at91sam9rl_devices.c
> @@ -33,10 +33,6 @@
>  #if defined(CONFIG_AT_HDMAC) || defined(CONFIG_AT_HDMAC_MODULE)
>  static u64 hdmac_dmamask = DMA_BIT_MASK(32);
>  
> -static struct at_dma_platform_data atdma_pdata = {
> -	.nr_channels	= 2,
> -};
> -
>  static struct resource hdmac_resources[] = {
>  	[0] = {
>  		.start	= AT91_BASE_SYS + AT91_DMA,
> @@ -51,12 +47,11 @@ static struct resource hdmac_resources[] = {
>  };
>  
>  static struct platform_device at_hdmac_device = {
> -	.name		= "at_hdmac",
> +	.name		= "at91sam9rl_dma",
>  	.id		= -1,
>  	.dev		= {
>  				.dma_mask		= &hdmac_dmamask,
>  				.coherent_dma_mask	= DMA_BIT_MASK(32),
> -				.platform_data		= &atdma_pdata,
>  	},
>  	.resource	= hdmac_resources,
>  	.num_resources	= ARRAY_SIZE(hdmac_resources),
> @@ -64,7 +59,6 @@ static struct platform_device at_hdmac_device = {
>  
>  void __init at91_add_device_hdmac(void)
>  {
> -	dma_cap_set(DMA_MEMCPY, atdma_pdata.cap_mask);
>  	platform_device_register(&at_hdmac_device);
>  }
>  #else


-- 
~Vinod

[PATCH 4/4] ARM: at91/dma: DMA controller registering with DT support

[Nicolas Ferre]

Device tree support on at91sam9g45 family SoC. Only call
platform_device_register() if no dma-controller node is
found in device tree.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9g45_devices.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index c9b897f..cee7287 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -64,7 +64,14 @@ static struct platform_device at_hdmac_device = {
 
 void __init at91_add_device_hdmac(void)
 {
-	platform_device_register(&at_hdmac_device);
+	struct device_node *of_node =
+		of_find_node_by_name(NULL, "dma-controller");
+
+	if (of_node) {
+		of_node_put(of_node);
+	} else {
+		platform_device_register(&at_hdmac_device);
+	}
 }
 #else
 void __init at91_add_device_hdmac(void) {}
-- 
1.7.5.4

[PATCH V2 4/4] ARM: at91/dma: DMA controller registering with DT support

[Nicolas Ferre]

Device tree support on at91sam9g45 family SoC. Only call
platform_device_register() if no compatible dma-controller
node is found in device tree.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
V2: use compatible string to match device.

 arch/arm/mach-at91/at91sam9g45_devices.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 9390ae6..2120055 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -64,7 +64,13 @@ static struct platform_device at_hdmac_device = {
 
 void __init at91_add_device_hdmac(void)
 {
-	platform_device_register(&at_hdmac_device);
+	struct device_node *np = of_find_node_by_name(NULL, "dma-controller");
+
+	if (np && of_device_is_compatible(np, "atmel,at91sam9g45-dma")) {
+		of_node_put(np);
+	} else {
+		platform_device_register(&at_hdmac_device);
+	}
 }
 #else
 void __init at91_add_device_hdmac(void) {}
-- 
1.7.5.4

Re: [PATCH V2 4/4] ARM: at91/dma: DMA controller registering with DT support

[Sergei Shtylyov]

Hello.

On 10-10-2011 20:43, Nicolas Ferre wrote:

> Device tree support on at91sam9g45 family SoC. Only call
> platform_device_register() if no compatible dma-controller
> node is found in device tree.

> Signed-off-by: Nicolas Ferre<nicolas.ferre@atmel.com>
> ---
> V2: use compatible string to match device.

[...]

> diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
> index 9390ae6..2120055 100644
> --- a/arch/arm/mach-at91/at91sam9g45_devices.c
> +++ b/arch/arm/mach-at91/at91sam9g45_devices.c
> @@ -64,7 +64,13 @@ static struct platform_device at_hdmac_device = {
>
>   void __init at91_add_device_hdmac(void)
>   {
> -	platform_device_register(&at_hdmac_device);
> +	struct device_node *np = of_find_node_by_name(NULL, "dma-controller");
> +
> +	if (np&&  of_device_is_compatible(np, "atmel,at91sam9g45-dma")) {
> +		of_node_put(np);
> +	} else {
> +		platform_device_register(&at_hdmac_device);
> +	}

    {} not needed here, and checkpatch.pl should have protested.

WBR, Sergei

Re: [PATCH 1/4] dmaengine: at_hdmac: platform data move to use .id_table

[Vinod Koul]

On Mon, 2011-10-10 at 18:37 +0200, Nicolas Ferre wrote:
> We remove platform data from DMA controller and move
> to the use of .id_table to distinguish between compatible
> types. The two implementations allow to determine the
> number of channels and the capabilities of the controller.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  drivers/dma/at_hdmac.c      |   48 ++++++++++++++++++++++++++++++++++---------
>  drivers/dma/at_hdmac_regs.h |    8 +++++++
>  2 files changed, 46 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index fcfa0a8..fef57bc 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -1175,6 +1175,18 @@ static void atc_free_chan_resources(struct dma_chan *chan)
>  
>  /*--  Module Management  -----------------------------------------------*/
>  
> +static struct platform_device_id atdma_devtypes[] = {
> +	{
> +		.name = "at91sam9rl_dma",
> +		.driver_data = ATDMA_DEVTYPE_SAM9RL,
> +	}, {
> +		.name = "at91sam9g45_dma",
> +		.driver_data = ATDMA_DEVTYPE_SAM9G45,
> +	}, {
> +		/* sentinel */
> +	}
> +};
> +
>  /**
>   * at_dma_off - disable DMA controller
>   * @atdma: the Atmel HDAMC device
> @@ -1193,18 +1205,32 @@ static void at_dma_off(struct at_dma *atdma)
>  
>  static int __init at_dma_probe(struct platform_device *pdev)
>  {
> -	struct at_dma_platform_data *pdata;
>  	struct resource		*io;
>  	struct at_dma		*atdma;
>  	size_t			size;
>  	int			irq;
>  	int			err;
>  	int			i;
> +	u32                     nr_channels;
> +	dma_cap_mask_t          cap_mask = {};
> +	enum atdma_devtype	atdmatype;
> +
> +	dma_cap_set(DMA_MEMCPY, cap_mask);
> +
> +	/* get DMA parameters from controller type */
> +	atdmatype = platform_get_device_id(pdev)->driver_data;
>  
> -	/* get DMA Controller parameters from platform */
> -	pdata = pdev->dev.platform_data;
> -	if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
> +	switch (atdmatype) {
> +	case ATDMA_DEVTYPE_SAM9RL:
> +		nr_channels = 2;
> +		break;
> +	case ATDMA_DEVTYPE_SAM9G45:
> +		nr_channels = 8;
> +		dma_cap_set(DMA_SLAVE, cap_mask);
> +		break;
> +	default:
>  		return -EINVAL;
> +	}
>  
>  	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	if (!io)
> @@ -1215,14 +1241,15 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  		return irq;
>  
>  	size = sizeof(struct at_dma);
> -	size += pdata->nr_channels * sizeof(struct at_dma_chan);
> +	size += nr_channels * sizeof(struct at_dma_chan);
>  	atdma = kzalloc(size, GFP_KERNEL);
>  	if (!atdma)
>  		return -ENOMEM;
>  
> -	/* discover transaction capabilites from the platform data */
> -	atdma->dma_common.cap_mask = pdata->cap_mask;
> -	atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
> +	/* discover transaction capabilites */
capabilities
> +	atdma->dma_common.cap_mask = cap_mask;
> +	atdma->all_chan_mask = (1 << nr_channels) - 1;
> +	atdma->devtype = atdmatype;
>  
>  	size = resource_size(io);
>  	if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
> @@ -1268,7 +1295,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  
>  	/* initialize channels related values */
>  	INIT_LIST_HEAD(&atdma->dma_common.channels);
> -	for (i = 0; i < pdata->nr_channels; i++) {
> +	for (i = 0; i < nr_channels; i++) {
>  		struct at_dma_chan	*atchan = &atdma->chan[i];
>  
>  		atchan->chan_common.device = &atdma->dma_common;
> @@ -1313,7 +1340,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
>  	  dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
>  	  dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",
> -	  pdata->nr_channels);
> +	  nr_channels);
indent?
>  
>  	dma_async_device_register(&atdma->dma_common);
>  
> @@ -1495,6 +1522,7 @@ static const struct dev_pm_ops at_dma_dev_pm_ops = {
>  static struct platform_driver at_dma_driver = {
>  	.remove		= __exit_p(at_dma_remove),
>  	.shutdown	= at_dma_shutdown,
> +	.id_table	= atdma_devtypes,
>  	.driver = {
>  		.name	= "at_hdmac",
>  		.pm	= &at_dma_dev_pm_ops,
> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
> index aa4c9ae..d7d6737 100644
> --- a/drivers/dma/at_hdmac_regs.h
> +++ b/drivers/dma/at_hdmac_regs.h
> @@ -248,9 +248,16 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
>  
>  /*--  Controller  ------------------------------------------------------*/
>  
> +enum atdma_devtype {
> +	ATDMA_DEVTYPE_UNDEFINED = 0,
> +	ATDMA_DEVTYPE_SAM9RL,	/* compatible with SAM9RL DMA controller */
> +	ATDMA_DEVTYPE_SAM9G45,	/* compatible with SAM9G45 DMA controller */
> +};
> +
>  /**
>   * struct at_dma - internal representation of an Atmel HDMA Controller
>   * @chan_common: common dmaengine dma_device object members
> + * @atdma_devtype: identifier of DMA controller compatibility
>   * @ch_regs: memory mapped register base
>   * @clk: dma controller clock
>   * @save_imr: interrupt mask register that is saved on suspend/resume cycle
> @@ -260,6 +267,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
>   */
>  struct at_dma {
>  	struct dma_device	dma_common;
> +	enum atdma_devtype	devtype;
>  	void __iomem		*regs;
>  	struct clk		*clk;
>  	u32			save_imr;
Little confused at this, where is the remove of existing platfrom data
per the changelog?

-- 
~Vinod

Re: [PATCH 1/4] dmaengine: at_hdmac: platform data move to use .id_table

[Nicolas Ferre]

On 10/11/2011 04:16 PM, Vinod Koul :
> On Mon, 2011-10-10 at 18:37 +0200, Nicolas Ferre wrote:
>> We remove platform data from DMA controller and move
>> to the use of .id_table to distinguish between compatible
>> types. The two implementations allow to determine the
>> number of channels and the capabilities of the controller.
>>
>> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
>> ---
>>  drivers/dma/at_hdmac.c      |   48 ++++++++++++++++++++++++++++++++++---------
>>  drivers/dma/at_hdmac_regs.h |    8 +++++++
>>  2 files changed, 46 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
>> index fcfa0a8..fef57bc 100644
>> --- a/drivers/dma/at_hdmac.c
>> +++ b/drivers/dma/at_hdmac.c
>> @@ -1175,6 +1175,18 @@ static void atc_free_chan_resources(struct dma_chan *chan)
>>  
>>  /*--  Module Management  -----------------------------------------------*/
>>  
>> +static struct platform_device_id atdma_devtypes[] = {
>> +	{
>> +		.name = "at91sam9rl_dma",
>> +		.driver_data = ATDMA_DEVTYPE_SAM9RL,
>> +	}, {
>> +		.name = "at91sam9g45_dma",
>> +		.driver_data = ATDMA_DEVTYPE_SAM9G45,
>> +	}, {
>> +		/* sentinel */
>> +	}
>> +};
>> +
>>  /**
>>   * at_dma_off - disable DMA controller
>>   * @atdma: the Atmel HDAMC device
>> @@ -1193,18 +1205,32 @@ static void at_dma_off(struct at_dma *atdma)
>>  
>>  static int __init at_dma_probe(struct platform_device *pdev)
>>  {
>> -	struct at_dma_platform_data *pdata;
>>  	struct resource		*io;
>>  	struct at_dma		*atdma;
>>  	size_t			size;
>>  	int			irq;
>>  	int			err;
>>  	int			i;
>> +	u32                     nr_channels;
>> +	dma_cap_mask_t          cap_mask = {};
>> +	enum atdma_devtype	atdmatype;
>> +
>> +	dma_cap_set(DMA_MEMCPY, cap_mask);
>> +
>> +	/* get DMA parameters from controller type */
>> +	atdmatype = platform_get_device_id(pdev)->driver_data;
>>  
>> -	/* get DMA Controller parameters from platform */
>> -	pdata = pdev->dev.platform_data;
>> -	if (!pdata || pdata->nr_channels > AT_DMA_MAX_NR_CHANNELS)
>> +	switch (atdmatype) {
>> +	case ATDMA_DEVTYPE_SAM9RL:
>> +		nr_channels = 2;
>> +		break;
>> +	case ATDMA_DEVTYPE_SAM9G45:
>> +		nr_channels = 8;
>> +		dma_cap_set(DMA_SLAVE, cap_mask);
>> +		break;
>> +	default:
>>  		return -EINVAL;
>> +	}
>>  
>>  	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>  	if (!io)
>> @@ -1215,14 +1241,15 @@ static int __init at_dma_probe(struct platform_device *pdev)
>>  		return irq;
>>  
>>  	size = sizeof(struct at_dma);
>> -	size += pdata->nr_channels * sizeof(struct at_dma_chan);
>> +	size += nr_channels * sizeof(struct at_dma_chan);
>>  	atdma = kzalloc(size, GFP_KERNEL);
>>  	if (!atdma)
>>  		return -ENOMEM;
>>  
>> -	/* discover transaction capabilites from the platform data */
>> -	atdma->dma_common.cap_mask = pdata->cap_mask;
>> -	atdma->all_chan_mask = (1 << pdata->nr_channels) - 1;
>> +	/* discover transaction capabilites */
> capabilities

Yes.

>> +	atdma->dma_common.cap_mask = cap_mask;
>> +	atdma->all_chan_mask = (1 << nr_channels) - 1;
>> +	atdma->devtype = atdmatype;
>>  
>>  	size = resource_size(io);
>>  	if (!request_mem_region(io->start, size, pdev->dev.driver->name)) {
>> @@ -1268,7 +1295,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>>  
>>  	/* initialize channels related values */
>>  	INIT_LIST_HEAD(&atdma->dma_common.channels);
>> -	for (i = 0; i < pdata->nr_channels; i++) {
>> +	for (i = 0; i < nr_channels; i++) {
>>  		struct at_dma_chan	*atchan = &atdma->chan[i];
>>  
>>  		atchan->chan_common.device = &atdma->dma_common;
>> @@ -1313,7 +1340,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>>  	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s), %d channels\n",
>>  	  dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
>>  	  dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",
>> -	  pdata->nr_channels);
>> +	  nr_channels);
> indent?

Well, this dev_info statement seems pretty well indented: if I use a
tab, then I cross the 80 column rule, and I would like to keep the "?:"
operator on one line... So I would like to keep it like this.

>>  	dma_async_device_register(&atdma->dma_common);
>>  
>> @@ -1495,6 +1522,7 @@ static const struct dev_pm_ops at_dma_dev_pm_ops = {
>>  static struct platform_driver at_dma_driver = {
>>  	.remove		= __exit_p(at_dma_remove),
>>  	.shutdown	= at_dma_shutdown,
>> +	.id_table	= atdma_devtypes,
>>  	.driver = {
>>  		.name	= "at_hdmac",
>>  		.pm	= &at_dma_dev_pm_ops,
>> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
>> index aa4c9ae..d7d6737 100644
>> --- a/drivers/dma/at_hdmac_regs.h
>> +++ b/drivers/dma/at_hdmac_regs.h
>> @@ -248,9 +248,16 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
>>  
>>  /*--  Controller  ------------------------------------------------------*/
>>  
>> +enum atdma_devtype {
>> +	ATDMA_DEVTYPE_UNDEFINED = 0,
>> +	ATDMA_DEVTYPE_SAM9RL,	/* compatible with SAM9RL DMA controller */
>> +	ATDMA_DEVTYPE_SAM9G45,	/* compatible with SAM9G45 DMA controller */
>> +};
>> +
>>  /**
>>   * struct at_dma - internal representation of an Atmel HDMA Controller
>>   * @chan_common: common dmaengine dma_device object members
>> + * @atdma_devtype: identifier of DMA controller compatibility
>>   * @ch_regs: memory mapped register base
>>   * @clk: dma controller clock
>>   * @save_imr: interrupt mask register that is saved on suspend/resume cycle
>> @@ -260,6 +267,7 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
>>   */
>>  struct at_dma {
>>  	struct dma_device	dma_common;
>> +	enum atdma_devtype	devtype;
>>  	void __iomem		*regs;
>>  	struct clk		*clk;
>>  	u32			save_imr;
> Little confused at this, where is the remove of existing platfrom data
> per the changelog?

Well, yes, it is the use of platform data that is removed, not the
structure it self. I change the log message in my v2 patch series.

thanks, bye,
-- 
Nicolas Ferre

Re: [PATCH 1/4] dmaengine: at_hdmac: platform data move to use .id_table

[Nicolas Ferre]

On 10/12/2011 06:34 PM, Nicolas Ferre :
> On 10/11/2011 04:16 PM, Vinod Koul :

[..]

>> Little confused at this, where is the remove of existing platfrom data
>> per the changelog?
> 
> Well, yes, it is the use of platform data that is removed, not the
> structure it self. I change the log message in my v2 patch series.

v3 actually...

Bye,
-- 
Nicolas Ferre