[PATCH v2 2/6] mtd: rawnand: tegra: add devicetree binding

[PATCH v2 2/6] mtd: rawnand: tegra: add devicetree binding

[Stefan Agner]

From: Lucas Stach <dev@lynxeye.de>

This adds the devicetree binding for the Tegra 2 NAND flash
controller.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 .../bindings/mtd/nvidia,tegra20-nand.txt      | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
new file mode 100644
index 000000000000..49e472af1b39
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
@@ -0,0 +1,62 @@
+NVIDIA Tegra NAND Flash controller
+
+Required properties:
+- compatible: Must be one of:
+  - "nvidia,tegra20-nand"
+- reg: MMIO address range
+- interrupts: interrupt output of the NFC controller
+- clocks: Must contain an entry for each entry in clock-names.
+  See ../clocks/clock-bindings.txt for details.
+- clock-names: Must include the following entries:
+  - nand
+- resets: Must contain an entry for each entry in reset-names.
+  See ../reset/reset.txt for details.
+- reset-names: Must include the following entries:
+  - nand
+
+Optional children nodes:
+Individual NAND chips are children of the NAND controller node. Currently
+only one NAND chip supported.
+
+Required children node properties:
+- reg: An integer ranging from 1 to 6 representing the CS line to use.
+
+Optional children node properties:
+- nand-ecc-mode: String, operation mode of the NAND ecc mode. "hw" by default
+- nand-ecc-algo: string, algorithm of NAND ECC.
+		 Supported values are: "rs", "bch".
+- nand-bus-width : 8 or 16 bus width if not present 8
+- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
+- nand-ecc-strength: integer representing the number of bits to correct
+		     per ECC step. Supported strength using HW ECC modes are:
+		     - RS: 4, 6, 8
+		     - BCH: 4, 8, 14, 16
+- nand-ecc-step-size: integer representing the number of data bytes
+		      that are covered by a single ECC step. Must be 512.
+- wp-gpios: GPIO specifier for the write protect pin.
+
+Optional child node of NAND chip nodes:
+Partitions: see partition.txt
+
+  Example:
+	nand@70008000 {
+		compatible = "nvidia,tegra20-nand";
+		reg = <0x70008000 0x100>;
+		interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
+		clock-names = "nand";
+		resets = <&tegra_car 13>;
+		reset-names = "nand";
+
+		nand-chip@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			nand-bus-width = <8>;
+			nand-on-flash-bbt;
+			nand-ecc-algo = "bch";
+			nand-ecc-step-size = <512>;
+			nand-ecc-strength = <8>;
+			wp-gpios = <&gpio TEGRA_GPIO(S, 0) GPIO_ACTIVE_LOW>;
+		};
+	};
-- 
2.17.0

Re: [PATCH v2 2/6] mtd: rawnand: tegra: add devicetree binding

[Miquel Raynal]

Hi Stefan,

On Sun, 27 May 2018 23:54:38 +0200, Stefan Agner <stefan@agner.ch>
wrote:

> From: Lucas Stach <dev@lynxeye.de>
> 
> This adds the devicetree binding for the Tegra 2 NAND flash
> controller.
> 
> Signed-off-by: Lucas Stach <dev@lynxeye.de>
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> ---
>  .../bindings/mtd/nvidia,tegra20-nand.txt      | 62 +++++++++++++++++++
>  1 file changed, 62 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> new file mode 100644
> index 000000000000..49e472af1b39
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> @@ -0,0 +1,62 @@
> +NVIDIA Tegra NAND Flash controller
> +
> +Required properties:
> +- compatible: Must be one of:

Nitpick: just put the compatible here as there is only one?

> +  - "nvidia,tegra20-nand"
> +- reg: MMIO address range
> +- interrupts: interrupt output of the NFC controller
> +- clocks: Must contain an entry for each entry in clock-names.
> +  See ../clocks/clock-bindings.txt for details.
> +- clock-names: Must include the following entries:
> +  - nand
> +- resets: Must contain an entry for each entry in reset-names.
> +  See ../reset/reset.txt for details.
> +- reset-names: Must include the following entries:
> +  - nand
> +
> +Optional children nodes:
> +Individual NAND chips are children of the NAND controller node. Currently
> +only one NAND chip supported.
> +
> +Required children node properties:
> +- reg: An integer ranging from 1 to 6 representing the CS line to use.

>From 1? It usually starts at 0.

> +
> +Optional children node properties:
> +- nand-ecc-mode: String, operation mode of the NAND ecc mode. "hw" by default
> +- nand-ecc-algo: string, algorithm of NAND ECC.
> +		 Supported values are: "rs", "bch".
> +- nand-bus-width : 8 or 16 bus width if not present 8
> +- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
> +- nand-ecc-strength: integer representing the number of bits to correct
> +		     per ECC step. Supported strength using HW ECC modes are:
> +		     - RS: 4, 6, 8
> +		     - BCH: 4, 8, 14, 16
> +- nand-ecc-step-size: integer representing the number of data bytes
> +		      that are covered by a single ECC step. Must be 512.

Please don't re-explain nand generic DT properties, point to nand.txt
instead.

> +- wp-gpios: GPIO specifier for the write protect pin.
> +
> +Optional child node of NAND chip nodes:
> +Partitions: see partition.txt
> +
> +  Example:
> +	nand@70008000 {
> +		compatible = "nvidia,tegra20-nand";
> +		reg = <0x70008000 0x100>;
> +		interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
> +		clocks = <&tegra_car TEGRA20_CLK_NDFLASH>;
> +		clock-names = "nand";
> +		resets = <&tegra_car 13>;
> +		reset-names = "nand";
> +
> +		nand-chip@0 {
> +			reg = <0>;
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +			nand-bus-width = <8>;
> +			nand-on-flash-bbt;
> +			nand-ecc-algo = "bch";
> +			nand-ecc-step-size = <512>;

In the driver you only refer to step sizes of 512 B, you can remove the
property from the bindings.

> +			nand-ecc-strength = <8>;
> +			wp-gpios = <&gpio TEGRA_GPIO(S, 0) GPIO_ACTIVE_LOW>;
> +		};
> +	};



-- 
Miquel Raynal, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v2 2/6] mtd: rawnand: tegra: add devicetree binding

[Rob Herring]

On Mon, May 28, 2018 at 12:23:54AM +0200, Miquel Raynal wrote:
> Hi Stefan,
> 
> On Sun, 27 May 2018 23:54:38 +0200, Stefan Agner <stefan@agner.ch>
> wrote:
> 
> > From: Lucas Stach <dev@lynxeye.de>
> > 
> > This adds the devicetree binding for the Tegra 2 NAND flash
> > controller.
> > 
> > Signed-off-by: Lucas Stach <dev@lynxeye.de>
> > Signed-off-by: Stefan Agner <stefan@agner.ch>
> > ---
> >  .../bindings/mtd/nvidia,tegra20-nand.txt      | 62 +++++++++++++++++++
> >  1 file changed, 62 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > new file mode 100644
> > index 000000000000..49e472af1b39
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > @@ -0,0 +1,62 @@
> > +NVIDIA Tegra NAND Flash controller
> > +
> > +Required properties:
> > +- compatible: Must be one of:
> 
> Nitpick: just put the compatible here as there is only one?

No, this is how I ask people to format it.

Rob

Re: [PATCH v2 2/6] mtd: rawnand: tegra: add devicetree binding

[Miquel Raynal]

Hi Rob,

On Wed, 30 May 2018 22:45:23 -0500, Rob Herring <robh@kernel.org> wrote:

> On Mon, May 28, 2018 at 12:23:54AM +0200, Miquel Raynal wrote:
> > Hi Stefan,
> > 
> > On Sun, 27 May 2018 23:54:38 +0200, Stefan Agner <stefan@agner.ch>
> > wrote:
> >   
> > > From: Lucas Stach <dev@lynxeye.de>
> > > 
> > > This adds the devicetree binding for the Tegra 2 NAND flash
> > > controller.
> > > 
> > > Signed-off-by: Lucas Stach <dev@lynxeye.de>
> > > Signed-off-by: Stefan Agner <stefan@agner.ch>
> > > ---
> > >  .../bindings/mtd/nvidia,tegra20-nand.txt      | 62 +++++++++++++++++++
> > >  1 file changed, 62 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > > 
> > > diff --git a/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > > new file mode 100644
> > > index 000000000000..49e472af1b39
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mtd/nvidia,tegra20-nand.txt
> > > @@ -0,0 +1,62 @@
> > > +NVIDIA Tegra NAND Flash controller
> > > +
> > > +Required properties:
> > > +- compatible: Must be one of:  
> > 
> > Nitpick: just put the compatible here as there is only one?  
> 
> No, this is how I ask people to format it.

Oh, ok, I'll remember it for my own DT patches then :)

Thanks,
Miquèl