ARM: shmobile: alt: Add QSPI device to DT

Enable the QSPI controller in the alt device tree.

Based similar work for the silk board by by Vladimir Barinov and Sergei Shtylyov.

---
v2
* Added compatible = "fixed-partitions";
* Update partitioning scheme to reflect ALT_MiniMonitor_Manual(SPI_Boot)_Rev0.01_e.pdf
* Tested on top of renesas-devel-20151228-v4.4-rc7 Read /dev/mtd0 with 512K blocks at 6.5Mb/s

---
 arch/arm/boot/dts/r8a7794-alt.dts | 46 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

index 2394e4883786..773f304d1142 100644
@@ -138,6 +138,13 @@
 	status = "okay";
 };
 
+&pfc {
+	qspi_pins: spi0 {
+		renesas,groups = "qspi_ctrl", "qspi_data4";
+		renesas,function = "qspi";
+	};
+};
+
 &ether {
 	pinctrl-0 = <&ether_pins &phy1_pins>;
 	pinctrl-names = "default";

@@ -197,3 +204,42 @@
 
 	status = "okay";
 };
+
+&qspi {
+	pinctrl-0 = <&qspi_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+
+	flash at 0 {
+		compatible = "spansion,s25fl512s", "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <30000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
+		spi-cpol;
+		spi-cpha;
+		m25p,fast-read;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition at 0 {
+				label = "loader";
+				reg = <0x00000000 0x00040000>;
+				read-only;
+			};
+			partition at 40000 {
+				label = "system";
+				reg = <0x00040000 0x00040000>;
+				read-only;
+			};
+			partition at 80000 {
+				label = "user";
+				reg = <0x00080000 0x03f80000>;
+			};
+		};
+	};
+};

2.1.4

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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

Thanks, I have queued this up for v4.6.

Should we document "spansion,s25fl512s" for the benefit of checkpatch.pl?

Hi Simon,

Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt used to point to drivers/mtd/devices/m25p80.c for the list of supported chips.

That seems to have been changed lately. Now jedec,spi-nor.txt includes the list, but lacks the manufacturers' names, so checkpatch.pl is still not happpy.

Brian: Shouldn't the manufacturers's names be added?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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

We've had some of this discussion recently:

http://lkml.kernel.org/g/20151118194340.GF140057 at google.com

I don't think we can reasonably determine a good list of complete strings, due to historical failures (IMO) in the SPI subsystem. We could add a separate list of possible manufacturers, so people can do the MxN pairing themselves.

checkpatch.pl has enough false positives that its author doesn't care to fix that I'm not personally worried about yet another class of them. But if you have good reasons and good patches for the documentation, I'm all ears.

Regards,
Brian