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Message-ID: <20190506182752.GA358@roeck-us.net>
Date: Mon, 6 May 2019 11:27:52 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Anson Huang <anson.huang@....com>
Cc: "robh+dt@...nel.org" <robh+dt@...nel.org>,
"mark.rutland@....com" <mark.rutland@....com>,
"wim@...ux-watchdog.org" <wim@...ux-watchdog.org>,
"shawnguo@...nel.org" <shawnguo@...nel.org>,
"s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
"kernel@...gutronix.de" <kernel@...gutronix.de>,
"festevam@...il.com" <festevam@...il.com>,
Aisheng Dong <aisheng.dong@....com>,
"ulf.hansson@...aro.org" <ulf.hansson@...aro.org>,
"sboyd@...nel.org" <sboyd@...nel.org>,
Daniel Baluta <daniel.baluta@....com>,
Peng Fan <peng.fan@....com>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-watchdog@...r.kernel.org" <linux-watchdog@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
dl-linux-imx <linux-imx@....com>
Subject: Re: [PATCH V3 3/3] watchdog: imx_sc: Add pretimeout support
On Sun, May 05, 2019 at 02:15:00AM +0000, Anson Huang wrote:
> i.MX system controller watchdog can support pretimeout IRQ
> via general SCU MU IRQ, it depends on IMX_SCU and driver MUST
> be probed after SCU IPC ready, then enable corresponding SCU
> IRQ group and register SCU IRQ notifier, when watchdog pretimeout
> IRQ fires, SCU MU IRQ will be handled and watchdog pretimeout
> notifier will be called to handle the event.
>
> Signed-off-by: Anson Huang <Anson.Huang@....com>
> ---
> No change.
> ---
> drivers/watchdog/Kconfig | 1 +
> drivers/watchdog/imx_sc_wdt.c | 114 ++++++++++++++++++++++++++++++++++--------
> 2 files changed, 95 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index e19960a..dbc74e1 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -710,6 +710,7 @@ config IMX2_WDT
> config IMX_SC_WDT
> tristate "IMX SC Watchdog"
> depends on HAVE_ARM_SMCCC
> + depends on IMX_SCU
> select WATCHDOG_CORE
> help
> This is the driver for the system controller watchdog
> diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
> index 49848b6..d8493a3 100644
> --- a/drivers/watchdog/imx_sc_wdt.c
> +++ b/drivers/watchdog/imx_sc_wdt.c
> @@ -4,6 +4,7 @@
> */
>
> #include <linux/arm-smccc.h>
> +#include <linux/firmware/imx/sci.h>
> #include <linux/io.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> @@ -33,11 +34,19 @@
>
> #define SC_TIMER_WDOG_ACTION_PARTITION 0
>
> +#define SC_IRQ_WDOG 1
> +#define SC_IRQ_GROUP_WDOG 1
> +
> static bool nowayout = WATCHDOG_NOWAYOUT;
> module_param(nowayout, bool, 0000);
> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>
> +struct imx_sc_wdt_device {
> + struct watchdog_device wdd;
> + struct notifier_block wdt_notifier;
> +};
> +
> static int imx_sc_wdt_ping(struct watchdog_device *wdog)
> {
> struct arm_smccc_res res;
> @@ -85,24 +94,66 @@ static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
> return res.a0 ? -EACCES : 0;
> }
>
> +static int imx_sc_wdt_set_pretimeout(struct watchdog_device *wdog,
> + unsigned int pretimeout)
> +{
> + struct arm_smccc_res res;
> +
> + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_PRETIME_WDOG,
> + pretimeout * 1000, 0, 0, 0, 0, 0, &res);
> + if (res.a0)
> + return -EACCES;
> +
> + wdog->pretimeout = pretimeout;
> +
> + return 0;
> +}
> +
> +static int imx_sc_wdt_notify(struct notifier_block *nb,
> + unsigned long event, void *group)
> +{
> + struct imx_sc_wdt_device *imx_sc_wdd =
> + container_of(nb,
> + struct imx_sc_wdt_device,
> + wdt_notifier);
> +
> + if (event & SC_IRQ_WDOG &&
> + *(u8 *)group == SC_IRQ_GROUP_WDOG)
> + watchdog_notify_pretimeout(&imx_sc_wdd->wdd);
> +
> + return 0;
> +}
> +
> +static void imx_sc_wdt_action(void *data)
> +{
> + struct notifier_block *wdt_notifier = data;
> +
> + imx_scu_irq_unregister_notifier(wdt_notifier);
> + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> + SC_IRQ_WDOG,
> + false);
> +}
> +
> static const struct watchdog_ops imx_sc_wdt_ops = {
> .owner = THIS_MODULE,
> .start = imx_sc_wdt_start,
> .stop = imx_sc_wdt_stop,
> .ping = imx_sc_wdt_ping,
> .set_timeout = imx_sc_wdt_set_timeout,
> + .set_pretimeout = imx_sc_wdt_set_pretimeout,
> };
>
> -static const struct watchdog_info imx_sc_wdt_info = {
> +static struct watchdog_info imx_sc_wdt_info = {
> .identity = "i.MX SC watchdog timer",
> .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> - WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT,
> + WDIOF_MAGICCLOSE,
> };
>
> static int imx_sc_wdt_probe(struct platform_device *pdev)
> {
> + struct imx_sc_wdt_device *imx_sc_wdd;
> + struct watchdog_device *wdog;
> struct device *dev = &pdev->dev;
> - struct watchdog_device *imx_sc_wdd;
> int ret;
>
> imx_sc_wdd = devm_kzalloc(dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
> @@ -111,42 +162,65 @@ static int imx_sc_wdt_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, imx_sc_wdd);
>
> - imx_sc_wdd->info = &imx_sc_wdt_info;
> - imx_sc_wdd->ops = &imx_sc_wdt_ops;
> - imx_sc_wdd->min_timeout = 1;
> - imx_sc_wdd->max_timeout = MAX_TIMEOUT;
> - imx_sc_wdd->parent = dev;
> - imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
> + wdog = &imx_sc_wdd->wdd;
> + wdog->info = &imx_sc_wdt_info;
> + wdog->ops = &imx_sc_wdt_ops;
> + wdog->min_timeout = 1;
> + wdog->max_timeout = MAX_TIMEOUT;
> + wdog->parent = dev;
> + wdog->timeout = DEFAULT_TIMEOUT;
>
> - watchdog_init_timeout(imx_sc_wdd, 0, dev);
> - watchdog_stop_on_reboot(imx_sc_wdd);
> - watchdog_stop_on_unregister(imx_sc_wdd);
> + watchdog_init_timeout(wdog, 0, dev);
> + watchdog_stop_on_reboot(wdog);
> + watchdog_stop_on_unregister(wdog);
>
> - ret = devm_watchdog_register_device(dev, imx_sc_wdd);
> + ret = devm_watchdog_register_device(dev, wdog);
> if (ret) {
> dev_err(dev, "Failed to register watchdog device\n");
> return ret;
> }
>
> - return 0;
> + ret = imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> + SC_IRQ_WDOG,
> + true);
> + if (ret) {
> + dev_warn(dev, "Enable irq failed, pretimeout NOT supported\n");
> + return 0;
> + }
> +
> + imx_sc_wdd->wdt_notifier.notifier_call = imx_sc_wdt_notify;
> + ret = imx_scu_irq_register_notifier(&imx_sc_wdd->wdt_notifier);
> + if (ret) {
> + imx_scu_irq_group_enable(SC_IRQ_GROUP_WDOG,
> + SC_IRQ_WDOG,
> + false);
> + dev_warn(dev,
> + "Register irq notifier failed, pretimeout NOT supported\n");
> + return 0;
> + }
> +
> + imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
> + ret = devm_add_action(dev, imx_sc_wdt_action,
> + &imx_sc_wdd->wdt_notifier);
This needs devm_add_action_or_reset() because otherwise the notifier would
not be removed, and the interrupt group would not be disabled.
> + return ret;
This should not return an error. Accepting that the notifier can not be
registered and that the irq group can not be enabled but bailing out if
devm_add_action() fails is inconsistent.
Guenter
> }
>
> static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
> {
> - struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
>
> - if (watchdog_active(imx_sc_wdd))
> - imx_sc_wdt_stop(imx_sc_wdd);
> + if (watchdog_active(&imx_sc_wdd->wdd))
> + imx_sc_wdt_stop(&imx_sc_wdd->wdd);
>
> return 0;
> }
>
> static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
> {
> - struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> + struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
>
> - if (watchdog_active(imx_sc_wdd))
> - imx_sc_wdt_start(imx_sc_wdd);
> + if (watchdog_active(&imx_sc_wdd->wdd))
> + imx_sc_wdt_start(&imx_sc_wdd->wdd);
>
> return 0;
> }
> --
> 2.7.4
>
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