From: Youngmin Nam <youngmin.nam@samsung.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: daniel.lezcano@linaro.org, tglx@linutronix.de,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, pullip.cho@samsung.com,
hoony.yu@samsung.com, hajun.sung@samsung.com,
myung-su.cha@samsung.com
Subject: Re: [PATCH v1 1/2] clocksource/drivers/exynos_mct_v2: introduce Exynos MCT version 2 driver for next Exynos SoC
Date: Mon, 1 Nov 2021 14:25:42 +0900 [thread overview]
Message-ID: <20211101052542.GA35671@perf> (raw)
In-Reply-To: <117dfec8-e417-642b-7647-9d17592826ad@canonical.com>
[-- Attachment #1: Type: text/plain, Size: 1312 bytes --]
On Wed, Oct 27, 2021 at 10:38:09AM +0200, Krzysztof Kozlowski wrote:
> On 21/10/2021 08:18, Youngmin Nam wrote:
> > Exynos MCT version 2 is composed of 1 FRC and 12 comparators.
> > The 12 comparators can produces interrupts independently,
> > so they can be used as local timer of each CPU.
> >
>
> ...
>
> > +
> > +static void exynos_mct_comp_start(struct mct_clock_event_device *mevt,
> > + bool periodic, unsigned long cycles)
> > +{
> > + unsigned int index = mevt->comp_index;
> > + unsigned int comp_enable;
> > + unsigned int loop_cnt = 0;
> > +
> > + comp_enable = readl_relaxed(reg_base + EXYNOS_MCT_COMP_ENABLE(index));
> > + if (comp_enable == MCT_COMP_ENABLE)
> > + exynos_mct_comp_stop(mevt);
> > +
> > + if (periodic)
> > + writel_relaxed(MCT_COMP_CIRCULAR_MODE, reg_base + EXYNOS_MCT_COMP_MODE(index));
> > +
> > + writel_relaxed(cycles, reg_base + EXYNOS_MCT_COMP_PERIOD(index));
>
> This is unsigned long, so 64-bit on your platform. Use writeq_relaxed or
> handle it somehow.
Thanks for your review.
I checked again and data sheet of MCTv2 shows compartor period has 32-bit data width.
Once we write 32bit value to comp_period register, H/W will produce interrupt when increasing FRC
is the same with the value of "current FRC + comp_period".
>
>
> Best regards,
> Krzysztof
>
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next prev parent reply other threads:[~2021-11-01 4:58 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20211021055104epcas2p4bd5278e58860af8c136a850c0f080087@epcas2p4.samsung.com>
2021-10-21 6:18 ` [PATCH v1 0/2] Indroduce Exynos Multi Core Timer version 2 Youngmin Nam
[not found] ` <CGME20211021055112epcas2p278145beb21cd6cc4217813a41c1e1407@epcas2p2.samsung.com>
2021-10-21 6:18 ` [PATCH v1 1/2] clocksource/drivers/exynos_mct_v2: introduce Exynos MCT version 2 driver for next Exynos SoC Youngmin Nam
2021-10-21 6:18 ` Krzysztof Kozlowski
2021-10-21 8:26 ` Youngmin Nam
2021-10-21 8:07 ` Krzysztof Kozlowski
2021-10-22 4:21 ` Youngmin Nam
2021-10-25 8:18 ` Krzysztof Kozlowski
2021-10-26 1:47 ` Youngmin Nam
2021-10-26 7:10 ` Krzysztof Kozlowski
2021-10-26 10:45 ` Youngmin Nam
2021-10-26 11:00 ` Krzysztof Kozlowski
[not found] ` <CGME20211027011125epcas2p2916524051416ede854b750c91a19073b@epcas2p2.samsung.com>
2021-10-27 1:38 ` Youngmin Nam
2021-10-27 6:39 ` Krzysztof Kozlowski
2021-11-01 6:04 ` Youngmin Nam
2021-10-27 7:34 ` Will Deacon
2021-10-29 3:54 ` Youngmin Nam
2021-10-26 11:00 ` Krzysztof Kozlowski
2021-10-27 8:38 ` Krzysztof Kozlowski
2021-11-01 5:25 ` Youngmin Nam [this message]
[not found] ` <CGME20211021055115epcas2p158fbf3ac61d3deeb5995bd100d7edef1@epcas2p1.samsung.com>
2021-10-21 6:18 ` [PATCH v1 2/2] dt-bindings: timer: samsung,s5e99xx-mct: Document s5e99xx-mct bindings Youngmin Nam
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