[PATCH] spi/pl022: Devicetree support w/o platform data

[PATCH] spi/pl022: Devicetree support w/o platform data

[Roland Stigge]

Even with devicetree support, we needed platform data to provide some data like
bus_id and enable_dma, leading to mixed device tree and platform data. This
patch makes it possible to provide all that information via device tree. Now,
the data must be provided via platform data _or_ device tree completely.

Only in case of callback specification (dma_filter()), platform data is
necessary.

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
 Documentation/devicetree/bindings/spi/spi_pl022.txt |    9 ++++
 drivers/spi/spi-pl022.c                             |   41 +++++++++++++++++---
 2 files changed, 45 insertions(+), 5 deletions(-)

--- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
+++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
@@ -10,6 +10,15 @@ Optional properties:
 - cs-gpios : should specify GPIOs used for chipselects.
   The gpios will be referred to as reg = <index> in the SPI child nodes.
   If unspecified, a single SPI device without a chip select can be used.
+- pl022,bus-id : Bus ID (0, 1, ...)
+- pl022,enable-dma : enables DMA driven transfers (boolean)
+- pl022,autosuspend-delay : delay in ms following transfer completion before
+			    the runtime power management system suspends the
+			    device. A setting of 0 indicates no delay and the
+                            device will be suspended immediately
+- pl022,rt : indicates the controller should run the message pump with realtime
+             priority to minimise the transfer latency on the bus (boolean)
+
 
 SPI slave nodes must be children of the SPI master node and can
 contain the following properties.
--- linux-2.6.orig/drivers/spi/spi-pl022.c
+++ linux-2.6/drivers/spi/spi-pl022.c
@@ -2024,6 +2024,36 @@ static void pl022_cleanup(struct spi_dev
 	kfree(chip);
 }
 
+static struct pl022_ssp_controller *
+pl022_platform_data_dt_get(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct pl022_ssp_controller *pd;
+	u32 tmp;
+
+	if (!np) {
+		dev_err(dev, "no dt node defined\n");
+		return NULL;
+	}
+
+	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
+	if (!pd) {
+		dev_err(dev, "cannot allocate platform data memory\n");
+		return NULL;
+	}
+
+	of_property_read_u32(np, "pl022,bus-id", &tmp);
+	pd->bus_id = tmp;
+	of_property_read_u32(np, "num-cs", &tmp);
+	pd->num_chipselect = tmp;
+	pd->enable_dma = of_property_read_bool(np, "pl022,enable-dma") ? 1 : 0;
+	of_property_read_u32(np, "pl022,autosuspend-delay",
+			     &pd->autosuspend_delay);
+	pd->rt = of_property_read_bool(np, "pl022,rt");
+
+	return pd;
+}
+
 static int __devinit
 pl022_probe(struct amba_device *adev, const struct amba_id *id)
 {
@@ -2036,18 +2066,19 @@ pl022_probe(struct amba_device *adev, co
 
 	dev_info(&adev->dev,
 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
-	if (platform_info == NULL) {
-		dev_err(&adev->dev, "probe - no platform data supplied\n");
+	if (!platform_info && IS_ENABLED(CONFIG_OF))
+		platform_info = pl022_platform_data_dt_get(dev);
+
+	if (!platform_info) {
+		dev_err(dev, "probe: no platform data defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}
 
 	if (platform_info->num_chipselect) {
 		num_cs = platform_info->num_chipselect;
-	} else if (IS_ENABLED(CONFIG_OF)) {
-		of_property_read_u32(np, "num-cs", &num_cs);
 	} else {
-		dev_err(&adev->dev, "probe: no chip select defined\n");
+		dev_err(dev, "probe: no chip select defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}

Re: [PATCH] spi/pl022: Devicetree support w/o platform data

[Linus Walleij]

On Mon, Sep 17, 2012 at 6:59 PM, Roland Stigge <stigge@antcom.de> wrote:

> Even with devicetree support, we needed platform data to provide some data like
> bus_id and enable_dma, leading to mixed device tree and platform data. This
> patch makes it possible to provide all that information via device tree. Now,
> the data must be provided via platform data _or_ device tree completely.
>
> Only in case of callback specification (dma_filter()), platform data is
> necessary.
>
> Signed-off-by: Roland Stigge <stigge@antcom.de>

This looks good so:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

But I think you need to page Mark Brown so it
gets picked to the stuff queued for the next merge window.
I think the dependent patch is in his SPI tree.

So I'd resend it to mark+grant with my ACK.

Yours,
Linus Walleij

Re: [PATCH] spi/pl022: Devicetree support w/o platform data

[Roland Stigge]

Hi!

On 09/18/2012 03:13 PM, Arnd Bergmann wrote:
> On Tuesday 18 September 2012, Roland Stigge wrote:
>> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
>> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
>> @@ -10,6 +10,15 @@ Optional properties:
>>  - cs-gpios : should specify GPIOs used for chipselects.
>>    The gpios will be referred to as reg = <index> in the SPI child nodes.
>>    If unspecified, a single SPI device without a chip select can be used.
>> +- pl022,bus-id : Bus ID (0, 1, ...)
> 
> I don't understand why we need the bus-id here. My understanding is that
> this is a linux-specific number that should not be necessary when all
> devices are described in the device tree rather than through spi_board_info.
> 
> Can't you just set master->bus_num to -1 when using the DT for probing?
> 
>> +- pl022,enable-dma : enables DMA driven transfers (boolean)
> 
> Similar thing here: Can't you just set the enable_dma flag when
> a dma channel is provided in the device tree and unset it otherwise?
> 
> It also seems a bit pointless to enable DMA mode when you don't provide
> a way to specify the channel at the same time.

Completely right! I'm removing pl022,bus-id, setting bus_id to -1 in the
dt case. And removing pl022,enable-dma since dma is anyway only useful
in the platform data case where the dma_filter() callback is specified.

Thanks for pointing this out,

Roland

Re: [PATCH] spi/pl022: Devicetree support w/o platform data

[Arnd Bergmann]

On Tuesday 18 September 2012, Roland Stigge wrote:
> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
> @@ -10,6 +10,15 @@ Optional properties:
>  - cs-gpios : should specify GPIOs used for chipselects.
>    The gpios will be referred to as reg = <index> in the SPI child nodes.
>    If unspecified, a single SPI device without a chip select can be used.
> +- pl022,bus-id : Bus ID (0, 1, ...)

I don't understand why we need the bus-id here. My understanding is that
this is a linux-specific number that should not be necessary when all
devices are described in the device tree rather than through spi_board_info.

Can't you just set master->bus_num to -1 when using the DT for probing?

> +- pl022,enable-dma : enables DMA driven transfers (boolean)

Similar thing here: Can't you just set the enable_dma flag when
a dma channel is provided in the device tree and unset it otherwise?

It also seems a bit pointless to enable DMA mode when you don't provide
a way to specify the channel at the same time.

	Arnd

Re: [PATCH] spi/pl022: Devicetree support w/o platform data

[Alexandre Pereira da Silva]

On Tue, Sep 18, 2012 at 9:49 AM, Roland Stigge <stigge@antcom.de> wrote:
> Even with devicetree support, we needed platform data to provide some data like
> bus_id and enable_dma, leading to mixed device tree and platform data. This
> patch makes it possible to provide all that information via device tree. Now,
> the data must be provided via platform data _or_ device tree completely.
>
> Only in case of callback specification (dma_filter()), platform data is
> necessary.
>
> Signed-off-by: Roland Stigge <stigge@antcom.de>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>

Acked-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>

> ---
>  Documentation/devicetree/bindings/spi/spi_pl022.txt |    9 ++++
>  drivers/spi/spi-pl022.c                             |   41 +++++++++++++++++---
>  2 files changed, 45 insertions(+), 5 deletions(-)
>
> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
> @@ -10,6 +10,15 @@ Optional properties:
>  - cs-gpios : should specify GPIOs used for chipselects.
>    The gpios will be referred to as reg = <index> in the SPI child nodes.
>    If unspecified, a single SPI device without a chip select can be used.
> +- pl022,bus-id : Bus ID (0, 1, ...)
> +- pl022,enable-dma : enables DMA driven transfers (boolean)
> +- pl022,autosuspend-delay : delay in ms following transfer completion before
> +                           the runtime power management system suspends the
> +                           device. A setting of 0 indicates no delay and the
> +                            device will be suspended immediately
> +- pl022,rt : indicates the controller should run the message pump with realtime
> +             priority to minimise the transfer latency on the bus (boolean)
> +
>
>  SPI slave nodes must be children of the SPI master node and can
>  contain the following properties.
> --- linux-2.6.orig/drivers/spi/spi-pl022.c
> +++ linux-2.6/drivers/spi/spi-pl022.c
> @@ -2024,6 +2024,36 @@ static void pl022_cleanup(struct spi_dev
>         kfree(chip);
>  }
>
> +static struct pl022_ssp_controller *
> +pl022_platform_data_dt_get(struct device *dev)
> +{
> +       struct device_node *np = dev->of_node;
> +       struct pl022_ssp_controller *pd;
> +       u32 tmp;
> +
> +       if (!np) {
> +               dev_err(dev, "no dt node defined\n");
> +               return NULL;
> +       }
> +
> +       pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
> +       if (!pd) {
> +               dev_err(dev, "cannot allocate platform data memory\n");
> +               return NULL;
> +       }
> +
> +       of_property_read_u32(np, "pl022,bus-id", &tmp);
> +       pd->bus_id = tmp;
> +       of_property_read_u32(np, "num-cs", &tmp);
> +       pd->num_chipselect = tmp;
> +       pd->enable_dma = of_property_read_bool(np, "pl022,enable-dma") ? 1 : 0;
> +       of_property_read_u32(np, "pl022,autosuspend-delay",
> +                            &pd->autosuspend_delay);
> +       pd->rt = of_property_read_bool(np, "pl022,rt");
> +
> +       return pd;
> +}
> +
>  static int __devinit
>  pl022_probe(struct amba_device *adev, const struct amba_id *id)
>  {
> @@ -2036,18 +2066,19 @@ pl022_probe(struct amba_device *adev, co
>
>         dev_info(&adev->dev,
>                  "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
> -       if (platform_info == NULL) {
> -               dev_err(&adev->dev, "probe - no platform data supplied\n");
> +       if (!platform_info && IS_ENABLED(CONFIG_OF))
> +               platform_info = pl022_platform_data_dt_get(dev);
> +
> +       if (!platform_info) {
> +               dev_err(dev, "probe: no platform data defined\n");
>                 status = -ENODEV;
>                 goto err_no_pdata;
>         }
>
>         if (platform_info->num_chipselect) {
>                 num_cs = platform_info->num_chipselect;
> -       } else if (IS_ENABLED(CONFIG_OF)) {
> -               of_property_read_u32(np, "num-cs", &num_cs);
>         } else {
> -               dev_err(&adev->dev, "probe: no chip select defined\n");
> +               dev_err(dev, "probe: no chip select defined\n");
>                 status = -ENODEV;
>                 goto err_no_pdata;
>         }

[PATCH] spi/pl022: Devicetree support w/o platform data

[Roland Stigge]

Even with devicetree support, we needed platform data to provide some data like
bus_id and enable_dma, leading to mixed device tree and platform data. This
patch makes it possible to provide all that information via device tree. Now,
the data must be provided via platform data _or_ device tree completely.

Only in case of callback specification (dma_filter()), platform data is
necessary.

Signed-off-by: Roland Stigge <stigge-uj/7R2tJ6VmzQB+pC5nmwQ@public.gmane.org>
Acked-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

---
 Documentation/devicetree/bindings/spi/spi_pl022.txt |    9 ++++
 drivers/spi/spi-pl022.c                             |   41 +++++++++++++++++---
 2 files changed, 45 insertions(+), 5 deletions(-)

--- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt
+++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt
@@ -10,6 +10,15 @@ Optional properties:
 - cs-gpios : should specify GPIOs used for chipselects.
   The gpios will be referred to as reg = <index> in the SPI child nodes.
   If unspecified, a single SPI device without a chip select can be used.
+- pl022,bus-id : Bus ID (0, 1, ...)
+- pl022,enable-dma : enables DMA driven transfers (boolean)
+- pl022,autosuspend-delay : delay in ms following transfer completion before
+			    the runtime power management system suspends the
+			    device. A setting of 0 indicates no delay and the
+                            device will be suspended immediately
+- pl022,rt : indicates the controller should run the message pump with realtime
+             priority to minimise the transfer latency on the bus (boolean)
+
 
 SPI slave nodes must be children of the SPI master node and can
 contain the following properties.
--- linux-2.6.orig/drivers/spi/spi-pl022.c
+++ linux-2.6/drivers/spi/spi-pl022.c
@@ -2024,6 +2024,36 @@ static void pl022_cleanup(struct spi_dev
 	kfree(chip);
 }
 
+static struct pl022_ssp_controller *
+pl022_platform_data_dt_get(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct pl022_ssp_controller *pd;
+	u32 tmp;
+
+	if (!np) {
+		dev_err(dev, "no dt node defined\n");
+		return NULL;
+	}
+
+	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
+	if (!pd) {
+		dev_err(dev, "cannot allocate platform data memory\n");
+		return NULL;
+	}
+
+	of_property_read_u32(np, "pl022,bus-id", &tmp);
+	pd->bus_id = tmp;
+	of_property_read_u32(np, "num-cs", &tmp);
+	pd->num_chipselect = tmp;
+	pd->enable_dma = of_property_read_bool(np, "pl022,enable-dma") ? 1 : 0;
+	of_property_read_u32(np, "pl022,autosuspend-delay",
+			     &pd->autosuspend_delay);
+	pd->rt = of_property_read_bool(np, "pl022,rt");
+
+	return pd;
+}
+
 static int __devinit
 pl022_probe(struct amba_device *adev, const struct amba_id *id)
 {
@@ -2036,18 +2066,19 @@ pl022_probe(struct amba_device *adev, co
 
 	dev_info(&adev->dev,
 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
-	if (platform_info == NULL) {
-		dev_err(&adev->dev, "probe - no platform data supplied\n");
+	if (!platform_info && IS_ENABLED(CONFIG_OF))
+		platform_info = pl022_platform_data_dt_get(dev);
+
+	if (!platform_info) {
+		dev_err(dev, "probe: no platform data defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}
 
 	if (platform_info->num_chipselect) {
 		num_cs = platform_info->num_chipselect;
-	} else if (IS_ENABLED(CONFIG_OF)) {
-		of_property_read_u32(np, "num-cs", &num_cs);
 	} else {
-		dev_err(&adev->dev, "probe: no chip select defined\n");
+		dev_err(dev, "probe: no chip select defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}