[PATCH 2/2] gpio: ixp4xx: Handle clock output on pin 14 and 15

Andy Shevchenko andy at kernel.org
Thu Sep 21 04:22:42 PDT 2023


On Thu, Sep 21, 2023 at 12:23:46AM +0200, Linus Walleij wrote:
> This makes it possible to provide basic clock output on pins
> 14 and 15. The clocks are typically used by random electronics,
> not modeled in the device tree, so they just need to be provided
> on request.

...

> +	val = __raw_readl(g->base + IXP4XX_REG_GPCLK);

Do we need to read this...

>  	/*
>  	 * Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on
>  	 * specific machines.
>  	 */
>  	if (of_machine_is_compatible("dlink,dsm-g600-a") ||
>  	    of_machine_is_compatible("iom,nas-100d"))
> -		__raw_writel(0x0, g->base + IXP4XX_REG_GPCLK);
> +		val = 0;

...if we are going to discard it anyway here?

Maybe

	if (...)
		val = 0;
	else
		val = readl();

?

...

> +	/*
> +	 * Enable clock outputs with default timings of requested clock.
> +	 * If you need control over TC and DC, add these to the device
> +	 * tree bindings and use them here.
> +	 */

Shouldn't this be integrated into PPS subsystem?

-- 
With Best Regards,
Andy Shevchenko





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