[OpenWrt-Devel] lantiq: Initial linux 4.4 support (with SPI problems)

[Daniel Schwierzeck]

Hi Martin,

Am Mittwoch, den 13.01.2016, 20:23 +0100 schrieb Martin Blumenstingl:
> Hi John,
> 
> On Mon, Jan 11, 2016 at 3:25 PM, Martin Blumenstingl
> <martin.blumenstingl at googlemail.com> wrote:
> > Here's the kernel log from the TD-W8970: 
> > https://paste.kde.org/pia7p73i9
> > I have debugged it and split_tplink_kernel gets 0x20000 as offset
> > and
> > 0x7A0000 as size (which looks correct). However, when mtd_read
> > tries to
> > read the magic bytes it only gets 0xFFFFFFFF.
> I found out that reverting this upstream commit makes SPI work again:
> [0]
> 
> Then I had a deeper look at our SPI driver - that's where I need some
> help from you.

could you retry with the attached driver? 

It is a complete rewrite with DT support and runs against the UGW-6.1.1
kernel. Unfortunately I hadn't time yet to adapt and test it with
OpenWRT. Maybe you want to volunteer for that ;)

The driver works on xRX200 with following DT bindings:

xrx200.dtsi:
fpi {
...
	spi: spi at e100800 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "lantiq,xrx200-spi";
		reg = <0xe100800 0x100>;
		interrupt-parent = <&icu0>;
		interrupts = <22 23 24 25>;
		interrupt-names = "spi_rx", "spi_tx", "spi_err",
					"spi_frm";

		status = "disabled";
	};
...
};


board.dts:

&gpio {
...
	pins_spi_default: pins_spi_default {
		spi_in {
			lantiq,groups = "spi_din";
			lantiq,function = "spi";
		};
		spi_out {
			lantiq,groups = "spi_dout", "spi_clk",
					"spi_cs4";
			lantiq,function = "spi";
			lantiq,output = <1>;
		};
	};
...
};

&spi {
	pinctrl-names = "default";
	pinctrl-0 = <&pins_spi_default>;

	status = "ok";

	m25p80 at 4 {
		#address-cells = <1>;
		#size-cells = <1>;
		compatible = "spansion,m25p80";
		reg = <4>;
		spi-max-frequency = <25000000>;
	};
};

-- 
- Daniel