Re: Subject: [PATCH 2/2] ARM: Layerscape: Add LS1021A IOT board support

[Sascha Hauer <sha@pengutronix.de>]

On Thu, Feb 23, 2023 at 01:58:46PM +0000, Renaud Barbier wrote:
> diff --git a/arch/arm/lib32/pbl.c b/arch/arm/lib32/pbl.c
> new file mode 100644
> index 0000000000..f4be7b57dc
> --- /dev/null
> +++ b/arch/arm/lib32/pbl.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <asm/system.h>
> +#include <clock.h>
> +#include <common.h>
> +
> +void udelay(unsigned long us)
> +{
> +	unsigned long long ticks, cntfrq = get_cntfrq();
> +	unsigned long long start = get_cntpct();
> +
> +	ticks = us * cntfrq + 999999;
> +	do_div(ticks, 1000000);
> +
> +	while ((long)(start + ticks - get_cntpct()) > 0);
> +}
> +
> +void mdelay(unsigned long ms)
> +{
> +	udelay(ms * 1000);
> +}

This will be compiled for every arm32 build, but the architected timer
is not generally available, only a small fraction of CPUs actually have
it. I just tested this on a i.MX6 and it just answers with an illegal
instruction abort when get_cntfrq() is called.

We could name this arm_architected_timer_udelay() or similar.

This change should be in a separate patch.

Sascha

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