[PATCH 2/4 v6] pinmux: add a driver for the U300 pinmux

[Stephen Warren]

Linus Walleij wrote at Thursday, September 01, 2011 3:33 AM:
> This adds a driver for the U300 pinmux portions of the system
> controller "SYSCON". It also serves as an example of how to use
> the pinmux subsystem. This driver also houses the platform data
> for the only supported platform.

> diff --git a/drivers/pinctrl/pinmux-u300.c b/drivers/pinctrl/pinmux-u300.c

> +/*
> + * We define explicit indexes of the groups since these will be
> + * referenced in the pinmuxes below.
> + */
> +#define POWERGRP_INDEX 0
> +#define UART0GRP_INDEX 1
> +#define MMC0GRP_INDEX 2
> +#define SPI0GRP_INDEX 3
> +
> +static const struct u300_pin_group u300_pin_groups[] = {
> +	[POWERGRP_INDEX] = {
> +		.name = "powergrp",
> +		.pins = power_pins,
> +		.num_pins = ARRAY_SIZE(power_pins),
> +	},
...
> +/**
> + * struct u300_pmx_func - describes U300 pinmux functions
> + * @name: the name of this specific function
> + * @groups: corresponding pin groups
> + * @onmask: bits to set to enable this when doing pin muxing
> + */
> +struct u300_pmx_func {
> +	const char *name;
> +	const unsigned groups[1];
> +	const struct u300_pmx_mask *mask;
> +};
> +
> +static const struct u300_pmx_func u300_pmx_functions[] = {
> +	{
> +		.name = "power",
> +		.groups = { POWERGRP_INDEX },
> +		/* Mask is N/A */
> +	},

Hmmm. That's a lot of _INDEX defines that'd need to be set up, at least
to fully represent a chip like Tegra. Can the pinmux core be modified
such that the group list is an array of names (char*) rather than the
actual numeric IDs of the groups? Still, perhaps we could use the enum
we already have for this, so perhaps it isn't a big deal...

-- 
nvpublic