Re: [PATCH v9 1/2] clocksource: loongson2_hpet: add hpet driver support

[Christophe JAILLET]

Le 03/11/2022 à 10:54, Yinbo Zhu a écrit :
> HPET (High Precision Event Timer) defines a new set of timers, which
> are used by the operating system to schedule threads, interrupt the
> kernel and interrupt the multimedia timer server. The operating
> system can assign different timers to different applications. By
> configuration, each timer can generate interrupt independently.
>
> The Loongson-2 HPET module includes a main count and three comparators,
> all of which are 32 bits wide. Among the three comparators, only
> one comparator supports periodic interrupt, all three comparators
> support non periodic interrupts.
>
> Signed-off-by: Yinbo Zhu <zhuyinbo-cXZgJK919ebM1kAEIRd3EQ@xxxxxxxxxxxxxxxx>
> ---

[...]

> +static int __init loongson2_hpet_init(struct device_node *np)
> +{
> +	struct clk *clk;
> +	int ret = -EINVAL;
> +
> +	hpet_mmio_base = of_iomap(np, 0);
> +	if (!hpet_mmio_base) {
> +		pr_err("hpet: unable to map loongson2 hpet registers\n");
> +		goto err;

Hi,

It looks odd to iounmap() after a failed of_iomap().
It is maybe fine on your arch, but still looks odd.

CJ

> +	}
> +
> +	hpet_t0_irq = irq_of_parse_and_map(np, 0);
> +	if (hpet_t0_irq <= 0) {
> +		pr_err("hpet: unable to get IRQ from DT, %d\n", hpet_t0_irq);
> +		goto err;
> +	}
> +
> +	clk = of_clk_get(np, 0);
> +	if (IS_ERR(clk))
> +		goto err;
> +
> +	hpet_freq = clk_get_rate(clk);
> +	clk_put(clk);
> +
> +	hpet_irq_flags = HPET_TN_LEVEL;
> +
> +	loongson2_hpet_clocksource_init();
> +
> +	loongson2_hpet_clockevent_init();
> +
> +	return 0;
> +
> +err:
> +	iounmap(hpet_mmio_base);
> +	return ret;
> +}
> +
> +TIMER_OF_DECLARE(loongson2_hpet, "loongson,ls2k-hpet", loongson2_hpet_init);