Re: [PATCH RESEND V4 3/3] watchdog: imx_sc: Add pretimeout support

[Guenter Roeck <linux@roeck-us.net>]

On Wed, Jun 05, 2019 at 06:24:33AM +0000, Anson Huang wrote:
> Hi, Guenter
> 
> > -----Original Message-----
> > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck
> > Sent: Sunday, May 12, 2019 9:28 PM
> > To: Anson Huang <anson.huang@nxp.com>; robh+dt@kernel.org;
> > mark.rutland@arm.com; wim@linux-watchdog.org; shawnguo@kernel.org;
> > s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com;
> > Aisheng Dong <aisheng.dong@nxp.com>; ulf.hansson@linaro.org; Daniel
> > Baluta <daniel.baluta@nxp.com>; Peng Fan <peng.fan@nxp.com>;
> > devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-
> > watchdog@vger.kernel.org; linux-arm-kernel@lists.infradead.org
> > Cc: dl-linux-imx <linux-imx@nxp.com>
> > Subject: Re: [PATCH RESEND V4 3/3] watchdog: imx_sc: Add pretimeout
> > support
> > 
> > On 5/12/19 3:10 AM, 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@nxp.com>
> > 
> > Revviewed-by: Guenter Roeck <linux@roeck-us.net>
> > 
> > Other patches waiting for DT review. IMX API feedback below.
> 
> Shaw just picked up the DT patch. Would you please pick up this driver and dt-binding patch
> to you git repo?
> 
I'll pick up patch 3/3, but I can not pick up patches into arch/arm64/boot/;
that is the responsibility of arm64 maintainers. I can only do that
if I get an explicit Ack and permission to do so from an arm64 maintainer,
and I don't recall getting that.

Guenter

> Thanks,
> Anson
> 
> > 
> > Side note: This patch depends on 'firmware: imx: enable imx scu general irq
> > function' which is not yet in mainline.
> > 
> > > ---
> > > No change, just resend patch with correct encoding.
> > > ---
> > >   drivers/watchdog/Kconfig      |   1 +
> > >   drivers/watchdog/imx_sc_wdt.c | 116
> > +++++++++++++++++++++++++++++++++++-------
> > >   2 files changed, 98 insertions(+), 19 deletions(-)
> > >
> > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index
> > > 7ea6037..e08238c 100644
> > > --- a/drivers/watchdog/Kconfig
> > > +++ b/drivers/watchdog/Kconfig
> > > @@ -716,6 +716,7 @@ 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..6ecc03f 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);
> > 
> > This should really not be necessary. Event mask and target group (if needed
> > with a wildcard for the group) should be parameters of
> > imx_scu_irq_register_notifier(), and be handled in the imx code.
> > 
> > Also, passing 'group' as pointed seems excessive. Might as well pass it
> > directly.
> > 
> > Guenter
> > 
> > > +
> > > +	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 +162,69 @@ 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;
> > >   	}
> > >
> > > +	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;
> > > +	}
> > > +
> > > +	ret = devm_add_action_or_reset(dev, imx_sc_wdt_action,
> > > +				       &imx_sc_wdd->wdt_notifier);
> > > +	if (!ret)
> > > +		imx_sc_wdt_info.options |= WDIOF_PRETIMEOUT;
> > > +	else
> > > +		dev_warn(dev, "Add action failed, pretimeout NOT
> > supported\n");
> > > +
> > >   	return 0;
> > >   }
> > >
> > >   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;
> > >   }
> > >
>