Re: [PATCH 3/3] arm: tegra: initial support for apalis t30

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 06/01/2014 05:37 PM, Marcel Ziswiler wrote:
> This patch adds the device tree to support Toradex Apalis T30, a
> computer on module which can be used on different carrier boards.
> 
> The module consists of a Tegra 3 SoC, two PMICs, 1 or 2 GB of DDR3L
> RAM, eMMC, an LM95245 temperature sensor chip, an i210 resp. i211
> gigabit Ethernet controller, an STMPE811 ADC/touch controller as well
> as two MCP2515 CAN controllers. Furthermore, there is an SGTL5000 audio
> codec which is not yet supported. Anything that is not self contained
> on the module is disabled by default.
> 
> The device tree for the Evaluation Board includes the modules device
> tree and enables the supported peripherals of the carrier board (the
> Evaluation Board supports almost all of them).
> 
> While at it also add the device tree binding documentation for Apalis
> T30 as well as the previously missing one for the recently added
> Colibri T30.

> diff --git a/arch/arm/boot/dts/tegra30-apalis-eval.dts b/arch/arm/boot/dts/tegra30-apalis-eval.dts

> +	/* SPI1: Apalis SPI1 */
> +	spi@7000d400 {
> +		status = "okay";
> +		spi-max-frequency = <25000000>;
> +		spidev0: spidev@1 {
> +			compatible = "spidev";
> +			reg = <1>;
> +			spi-max-frequency = <25000000>;
> +		};
> +	};

I vaguely recall people speaking out against including "spidev" devices
in DT because they don't represent actual HW, but rather a way to
request that the SPI bus be exposed to user-space, which is a pure SW
issue. Wouldn't it be better if the spidev interface worked like
I2C_CHARDEV, where fake devices weren't actually required?