[PATCH] spi: dw-mmio: add oftree support

[PATCH] spi: dw-mmio: add oftree support

[Steffen Trumtrar]

Allow probing the dw-mmio from devicetree.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
This was tested on Socfpga and v3.14-rc6

 .../devicetree/bindings/spi/spi-dw-mmio.txt        | 25 ++++++++++++++++++++++
 drivers/spi/spi-dw-mmio.c                          | 19 +++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-dw-mmio.txt

diff --git a/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt b/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt
new file mode 100644
index 0000000..2b9bb90
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt
@@ -0,0 +1,25 @@
+Synopsys DesignWare SPI master controller.
+
+Required properties:
+- compatible : "snps,dw-spi-mmio"
+- reg : The register base for the controller.
+- interrupts : One interrupt, used by the controller.
+- #address-cells : <1>, as required by generic SPI binding.
+- #size-cells : <0>, also as required by generic SPI binding.
+
+Optional properties:
+- num-chipselects : The number of chipselects.
+
+Child nodes as per the generic SPI binding.
+
+Example:
+
+	spi@fff00000 {
+		compatible = "snps,dw-spi-mmio";
+		reg = <0xfff00000 0x1000>;
+		interrupts = <0 154 4>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		num-chipselects = <4>;
+	};
+
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index 9af56cd..71345e4 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -16,6 +16,8 @@
 #include <linux/spi/spi.h>
 #include <linux/scatterlist.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
 
 #include "spi-dw.h"
 
@@ -32,6 +34,7 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
 	struct dw_spi *dws;
 	struct resource *mem;
 	int ret;
+	int val;
 
 	dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
 			GFP_KERNEL);
@@ -66,8 +69,15 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	dws->bus_num = 0;
+	dws->bus_num = pdev->id;
 	dws->num_cs = 4;
+
+	if (pdev->dev.of_node) {
+		if (of_property_read_u32(pdev->dev.of_node, "num-chipselects",
+					 &val))
+			dws->num_cs = val;
+	}
+
 	dws->max_freq = clk_get_rate(dwsmmio->clk);
 
 	ret = dw_spi_add_host(&pdev->dev, dws);
@@ -92,12 +102,19 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id dw_spi_mmio_of_match[] = {
+	{ .compatible = "snps,dw-spi-mmio", },
+	{ /* end of table */}
+};
+MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
+
 static struct platform_driver dw_spi_mmio_driver = {
 	.probe		= dw_spi_mmio_probe,
 	.remove		= dw_spi_mmio_remove,
 	.driver		= {
 		.name	= DRIVER_NAME,
 		.owner	= THIS_MODULE,
+		.of_match_table = dw_spi_mmio_of_match,
 	},
 };
 module_platform_driver(dw_spi_mmio_driver);
-- 
1.9.0

Re: [PATCH] spi: dw-mmio: add oftree support

[Mark Rutland]

On Fri, Mar 14, 2014 at 08:55:26AM +0000, Steffen Trumtrar wrote:
> Allow probing the dw-mmio from devicetree.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> ---
> This was tested on Socfpga and v3.14-rc6
> 
>  .../devicetree/bindings/spi/spi-dw-mmio.txt        | 25 ++++++++++++++++++++++
>  drivers/spi/spi-dw-mmio.c                          | 19 +++++++++++++++-
>  2 files changed, 43 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/spi/spi-dw-mmio.txt
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt b/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt
> new file mode 100644
> index 0000000..2b9bb90
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-dw-mmio.txt
> @@ -0,0 +1,25 @@
> +Synopsys DesignWare SPI master controller.
> +
> +Required properties:
> +- compatible : "snps,dw-spi-mmio"

Is there not a better name than "dw-spi-mmio"?

What's the full name of the device, as on a datasheet? Is there no model
number?

Otherwise this looks ok.

> +- reg : The register base for the controller.
> +- interrupts : One interrupt, used by the controller.
> +- #address-cells : <1>, as required by generic SPI binding.
> +- #size-cells : <0>, also as required by generic SPI binding.
> +
> +Optional properties:
> +- num-chipselects : The number of chipselects.

If this is optional, when wuold I need to set this? What's the default
assumption?

Mark: I see some bindings have "num-chipselects", and some have
"num-cs". Do you have a preferred form that people could align on?

Cheers,
Mark.

Re: [PATCH] spi: dw-mmio: add oftree support

[Mark Brown]

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On Fri, Mar 14, 2014 at 04:14:03PM +0000, Mark Rutland wrote:

> > +Synopsys DesignWare SPI master controller.
> > +
> > +Required properties:
> > +- compatible : "snps,dw-spi-mmio"

> Is there not a better name than "dw-spi-mmio"?

> What's the full name of the device, as on a datasheet? Is there no model
> number?

It's a Synopsis Designware IP block rather than a part - Google suggests
DW_apb_ssi.

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Re: [PATCH] spi: dw-mmio: add oftree support

[Mark Brown]

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On Fri, Mar 14, 2014 at 04:14:03PM +0000, Mark Rutland wrote:
> On Fri, Mar 14, 2014 at 08:55:26AM +0000, Steffen Trumtrar wrote:

> > +Optional properties:
> > +- num-chipselects : The number of chipselects.

> If this is optional, when wuold I need to set this? What's the default
> assumption?

> Mark: I see some bindings have "num-chipselects", and some have
> "num-cs". Do you have a preferred form that people could align on?

Probably -cs but the whole thing needs reviewing anyway for handling of
GPIO based chipselects.

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Re: [PATCH] spi: dw-mmio: add oftree support

[Steffen Trumtrar]

Hi!

On Fri, Mar 14, 2014 at 04:26:14PM +0000, Mark Brown wrote:
> On Fri, Mar 14, 2014 at 04:14:03PM +0000, Mark Rutland wrote:
> 
> > > +Synopsys DesignWare SPI master controller.
> > > +
> > > +Required properties:
> > > +- compatible : "snps,dw-spi-mmio"
> 
> > Is there not a better name than "dw-spi-mmio"?
> 
> > What's the full name of the device, as on a datasheet? Is there no model
> > number?
> 
> It's a Synopsis Designware IP block rather than a part - Google suggests
> DW_apb_ssi.

That seems to be the correct IP block, so I will change the compatible to
"snps,dw-apb-ssi".

Thanks,
Steffen

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