From: Guenter Roeck <linux@roeck-us.net>
To: Philippe Boos <pboos@baylibre.com>,
Wim Van Sebroeck <wim@linux-watchdog.org>,
Neil Armstrong <narmstrong@baylibre.com>
Cc: Kevin Hilman <khilman@baylibre.com>,
Jerome Brunet <jbrunet@baylibre.com>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
"open list:WATCHDOG DEVICE DRIVERS"
<linux-watchdog@vger.kernel.org>,
"moderated list:ARM/Amlogic Meson SoC support"
<linux-arm-kernel@lists.infradead.org>,
"open list:ARM/Amlogic Meson SoC support"
<linux-amlogic@lists.infradead.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] watchdog: meson: keep running if already active
Date: Mon, 8 Aug 2022 04:58:56 -0700 [thread overview]
Message-ID: <7ab495dd-4b3e-46e8-6db0-1dd20860043f@roeck-us.net> (raw)
In-Reply-To: <20220801092150.4449-1-pboos@baylibre.com>
On 8/1/22 02:21, Philippe Boos wrote:
> If the watchdog is already running (e.g.: started by bootloader) then
> the kernel driver should keep the watchdog active but the amlogic driver
> turns it off.
>
> Let the driver fix the clock rate if already active because we do not
> know the previous timebase value. To avoid unintentional resetting we
> temporarily set it to its maximum value.
>
> Then keep the enable bit if is was previously active.
>
> Signed-off-by: Philippe Boos <pboos@baylibre.com>
What changed since v1 ?
Guenter
> ---
> drivers/watchdog/meson_gxbb_wdt.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 5a9ca10fbcfa..8be8fd9e5637 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -146,6 +146,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct meson_gxbb_wdt *data;
> int ret;
> + u32 ctrl_reg;
>
> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> @@ -177,13 +178,26 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
> data->wdt_dev.timeout = DEFAULT_TIMEOUT;
> watchdog_set_drvdata(&data->wdt_dev, data);
>
> + ctrl_reg = readl(data->reg_base + GXBB_WDT_CTRL_REG) &
> + GXBB_WDT_CTRL_EN;
> +
> + if (ctrl_reg) {
> + /* Watchdog is running - keep it running but extend timeout
> + * to the maximum while setting the timebase
> + */
> + set_bit(WDOG_HW_RUNNING, &data->wdt_dev.status);
> + meson_gxbb_wdt_set_timeout(&data->wdt_dev,
> + GXBB_WDT_TCNT_SETUP_MASK / 1000);
> + }
> +
> /* Setup with 1ms timebase */
> - writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
> - GXBB_WDT_CTRL_EE_RESET |
> - GXBB_WDT_CTRL_CLK_EN |
> - GXBB_WDT_CTRL_CLKDIV_EN,
> - data->reg_base + GXBB_WDT_CTRL_REG);
> + ctrl_reg |= ((clk_get_rate(data->clk) / 1000) &
> + GXBB_WDT_CTRL_DIV_MASK) |
> + GXBB_WDT_CTRL_EE_RESET |
> + GXBB_WDT_CTRL_CLK_EN |
> + GXBB_WDT_CTRL_CLKDIV_EN;
>
> + writel(ctrl_reg, data->reg_base + GXBB_WDT_CTRL_REG);
> meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
>
> watchdog_stop_on_reboot(&data->wdt_dev);
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-08-08 12:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-01 9:21 [PATCH v2] watchdog: meson: keep running if already active Philippe Boos
2022-08-08 11:58 ` Guenter Roeck [this message]
2022-08-11 14:03 ` Philippe Boos
2022-09-06 12:21 ` Jerome Brunet
2022-09-25 15:40 ` Guenter Roeck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7ab495dd-4b3e-46e8-6db0-1dd20860043f@roeck-us.net \
--to=linux@roeck-us.net \
--cc=jbrunet@baylibre.com \
--cc=khilman@baylibre.com \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-watchdog@vger.kernel.org \
--cc=martin.blumenstingl@googlemail.com \
--cc=narmstrong@baylibre.com \
--cc=pboos@baylibre.com \
--cc=wim@linux-watchdog.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).