[EXT] Re: [PATCH v4 3/4] clocksource/drivers/timer-mediatek: Convert timer-mediatek to a loadable module

[Zhipeng Wang]

Hi Daniel,

Thank you for sharing your RFC patch. I think the approach is very
interesting and addresses a real problem in the timer subsystem.

For the MediaTek and IMX timer driver, I see a few considerations:

1. Current approach: My current patch uses the existing pattern
   (similar to renesas-ostm.c) with #ifdef MODULE. It's simple and
   works, but I agree it's not ideal.
2. Your approach: Your TIMER_OF_DECLARE_PDEV approach would be
   cleaner and allow us to use devm_ functions, which would be a
   nice improvement.
3. MediaTek and IMX timer specifics: The IMX timer doesn't require
   early initialization on modern platforms (we have arch timers on
   ARM64), so it would fit well with your TIMER_OF_DECLARE_PLATFORM_DRIVER
   macro (if you go with the two-macro approach).

I'm very interested in your approach. May I ask what timeline you're
considering for your patch series?
The reason I ask is that we're working towards GKI support and I want
to make sure I choose the right approach.

BRs,
Zhipeng
> -----Original Message-----
> From: Daniel Lezcano <daniel.lezcano at oss.qualcomm.com>
> Sent: 2026年3月5日 3:03
> To: Zhipeng Wang <zhipeng.wang_1 at nxp.com>
> Cc: daniel.lezcano at linaro.org; tglx at kernel.org; shawnguo at kernel.org;
> s.hauer at pengutronix.de; kernel at pengutronix.de; festevam at gmail.com;
> matthias.bgg at gmail.com; angelogioacchino.delregno at collabora.com;
> linux-kernel at vger.kernel.org; imx at lists.linux.dev;
> linux-arm-kernel at lists.infradead.org; linux-mediatek at lists.infradead.org;
> chun-hung.wu at mediatek.com; walter.chang at mediatek.com;
> jstultz at google.com; amergnat at baylibre.com; Aisheng Dong
> <aisheng.dong at nxp.com>; Jindong Yue <jindong.yue at nxp.com>; Xuegang Liu
> <xuegang.liu at nxp.com>
> Subject: [EXT] Re: [PATCH v4 3/4] clocksource/drivers/timer-mediatek: Convert
> timer-mediatek to a loadable module
>
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>
> On Wed, Mar 04, 2026 at 05:12:06PM +0900, Zhipeng Wang wrote:
> > From: Chun-Hung Wu <chun-hung.wu at mediatek.com>
> >
> > Convert the timer-mediatek driver into a loadable module so that it
> > can register an always-on timer as the tick_broadcast_device on
> > MediaTek SoCs. This helps support GKI(Generic Kernel Image) modular
> > configurations.
> >
> > Signed-off-by: Chun-Hung Wu <chun-hung.wu at mediatek.com>
> > Signed-off-by: Walter Chang <walter.chang at mediatek.com>
> > Tested-by: Walter Chang <walter.chang at mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno
> > <angelogioacchino.delregno at collabora.com>
> > Reviewed-by: Alexandre Mergnat <amergnat at baylibre.com>
> > Signed-off-by: Zhipeng Wang <zhipeng.wang_1 at nxp.com>
> > ---
> >  drivers/clocksource/Kconfig          |  2 +-
> >  drivers/clocksource/timer-mediatek.c | 33
> > ++++++++++++++++++++++++++++
> >  2 files changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> > index fd9112706545..2112efb85029 100644
> > --- a/drivers/clocksource/Kconfig
> > +++ b/drivers/clocksource/Kconfig
> > @@ -488,7 +488,7 @@ config SYS_SUPPORTS_SH_CMT
> >       bool
> >
> >  config MTK_TIMER
> > -     bool "Mediatek timer driver" if COMPILE_TEST
> > +     tristate "MediaTek timer driver"
> >       depends on HAS_IOMEM
> >       select TIMER_OF
> >       select CLKSRC_MMIO
> > diff --git a/drivers/clocksource/timer-mediatek.c
> > b/drivers/clocksource/timer-mediatek.c
> > index 7bcb4a3f26fb..4ad4bac6f34b 100644
> > --- a/drivers/clocksource/timer-mediatek.c
> > +++ b/drivers/clocksource/timer-mediatek.c
> > @@ -13,6 +13,9 @@
> >  #include <linux/clocksource.h>
> >  #include <linux/interrupt.h>
> >  #include <linux/irqreturn.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_device.h>
> >  #include <linux/sched_clock.h>
> >  #include <linux/slab.h>
> >  #include "timer-of.h"
> > @@ -337,5 +340,35 @@ static int __init mtk_gpt_init(struct device_node
> > *node)
> >
> >       return 0;
> >  }
> > +
> > +#ifndef MODULE
> >  TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer",
> mtk_gpt_init);
> > TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer",
> mtk_syst_init);
> > +#else
> > +static int mtk_timer_probe(struct platform_device *pdev) {
> > +     int (*timer_init)(struct device_node *node);
> > +     struct device_node *np = pdev->dev.of_node;
> > +
> > +     timer_init = of_device_get_match_data(&pdev->dev);
> > +     return timer_init(np);
> > +}
> > +
> > +static const struct of_device_id mtk_timer_match_table[] = {
> > +     { .compatible = "mediatek,mt6577-timer", .data = mtk_gpt_init },
> > +     { .compatible = "mediatek,mt6765-timer", .data = mtk_syst_init },
> > +     { /* sentinel */ }
> > +};
> > +
> > +static struct platform_driver mtk_timer_driver = {
> > +     .probe = mtk_timer_probe,
> > +     .driver = {
> > +             .name = "mediatek-timer",
> > +             .of_match_table = mtk_timer_match_table,
> > +     },
> > +};
> > +module_platform_driver(mtk_timer_driver);
> > +
> > +MODULE_DESCRIPTION("MediaTek Timer driver");
> MODULE_LICENSE("GPL");
> > +#endif
>
> What do you think about the approach found here:
>
> https://lore.ker/
> nel.org%2Fall%2F20250625085715.889837-1-daniel.lezcano%40linaro.org%2
> F&data=05%7C02%7Czhipeng.wang_1%40nxp.com%7Cf1fa174b13094e25d92
> 308de7a209d3b%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63
> 9082477664309790%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnR
> ydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3
> D%3D%7C0%7C%7C%7C&sdata=Dn4Qd9IdMYON0dLy2BRnN5FV3k1C2Cm3yv
> dS%2Bd%2BFn20%3D&reserved=0
>
> > --
> > 2.34.1
> >
>
> --