diff mbox

[v2,6/8,RFC] Documentation: dt: Add Renesas RSPI/QSPI bindings

Message ID 1388175362-17132-7-git-send-email-geert@linux-m68k.org (mailing list archive)
State New, archived
Headers show

Commit Message

Geert Uytterhoeven Dec. 27, 2013, 8:16 p.m. UTC
From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Cc: devicetree@vger.kernel.org
---
v2:
  - Clarify RSPI/QSPI
  - Add interrupt-parent
  - s/should/must/ for #address-cells and #size-cells

 Documentation/devicetree/bindings/spi/spi-rspi.txt |   31 ++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/spi/spi-rspi.txt

Comments

Mark Brown Dec. 30, 2013, 12:58 p.m. UTC | #1
On Fri, Dec 27, 2013 at 09:16:00PM +0100, Geert Uytterhoeven wrote:
> From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
> Cc: devicetree@vger.kernel.org

You've not CCed any maintainers on any of this stuff so I'm assuming you
don't want any review or the patches applying.  You should in general
always CC maintainers, things that only go to the list can easily be
missed.  However I did take a brief look...

> +- num-cs	   : Number of chip selects

Why is this variable and how does this map onto hardware?
Geert Uytterhoeven Dec. 30, 2013, 1:43 p.m. UTC | #2
On Mon, Dec 30, 2013 at 1:58 PM, Mark Brown <broonie@kernel.org> wrote:
> On Fri, Dec 27, 2013 at 09:16:00PM +0100, Geert Uytterhoeven wrote:
>> From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
>>
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
>> Cc: devicetree@vger.kernel.org
>
> You've not CCed any maintainers on any of this stuff so I'm assuming you
> don't want any review or the patches applying.  You should in general

Sorry, this was indeed not meant to be applied yet, hence the [RFC].
Will CC you explicitly next time.

> always CC maintainers, things that only go to the list can easily be
> missed.  However I did take a brief look...

Thanks!

>> +- num-cs        : Number of chip selects
>
> Why is this variable and how does this map onto hardware?

It's my understanding that legacy RSPi on SH7757 has 2 chip selects,
while other RSPI implementations have 1 chip select.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Mark Brown Dec. 30, 2013, 1:50 p.m. UTC | #3
On Mon, Dec 30, 2013 at 02:43:53PM +0100, Geert Uytterhoeven wrote:
> On Mon, Dec 30, 2013 at 1:58 PM, Mark Brown <broonie@kernel.org> wrote:
> > On Fri, Dec 27, 2013 at 09:16:00PM +0100, Geert Uytterhoeven wrote:

> >> +- num-cs        : Number of chip selects

> > Why is this variable and how does this map onto hardware?

> It's my understanding that legacy RSPi on SH7757 has 2 chip selects,
> while other RSPI implementations have 1 chip select.

So this should be documented in the binding document in a way that
allows someone reading the document and looking at the datasheet to
figure out how to pick the value (for example, refer to how the chip
selects are controlled in the hardware).
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/spi/spi-rspi.txt b/Documentation/devicetree/bindings/spi/spi-rspi.txt
new file mode 100644
index 000000000000..504db8917927
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-rspi.txt
@@ -0,0 +1,31 @@ 
+Device tree configuration for Renesas RSPI/QSPI driver
+
+Required properties:
+- compatible       : For Renesas Serial Peripheral Interface:
+                     "renesas,rspi-<soctype>", "renesas,rspi-rz" as fallback.
+		     For Quad Serial Peripheral Interface:
+		     "renesas,qspi-<soctype>", "renesas,qspi-rcar" as fallback.
+- reg              : address start and address range size of device
+- interrupts       : 3 interrupts for RSPI (SPEI, SPRI, SPTI),
+		     1 interrupt for QSPI
+- interrupt-parent : the phandle for the interrupt controller that
+		     services interrupts for this device.
+- num-cs	   : Number of chip selects
+- #address-cells   : must be <1>
+- #size-cells      : must be <0>
+
+Pinctrl properties might be needed, too. See there.
+
+Example:
+
+	spi0: spi@e800c800 {
+		compatible = "renesas,rspi-r7s72100", "renesas,rspi-rz";
+		reg = <0xe800c800 0x24>;
+		interrupts = <0 238 IRQ_TYPE_LEVEL_HIGH>,
+			     <0 239 IRQ_TYPE_LEVEL_HIGH>,
+			     <0 240 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-parent = <&gic>;
+		num-cs = <1>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};