lkml.org 
[lkml]   [2014]   [Dec]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v3] gpio_wdt: Add "always_running" feature to GPIO watchdog
    Is this v3 patch okay or are you waiting for additional changes?

    Kind regards,
    Mike.

    On 11/21/2014 10:40 AM, Mike Looijmans wrote:
    > On some chips, like the TPS386000, the trigger cannot be disabled
    > and the CPU must keep toggling the line at all times. Add a switch
    > "always_running" to keep toggling the GPIO line regardless of the
    > state of the soft part of the watchdog. The "armed" member keeps
    > track of whether a timeout must also cause a reset.
    >
    > Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
    > ---
    > v3: Indentation adjusted to match
    > Fix error path in probe when notification registration fails
    > Prevent double assignment of "armed" variable
    >
    > .../devicetree/bindings/watchdog/gpio-wdt.txt | 5 +++
    > drivers/watchdog/gpio_wdt.c | 39 ++++++++++++++++----
    > 2 files changed, 36 insertions(+), 8 deletions(-)
    >
    > diff --git a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt
    > index 37afec1..1987949 100644
    > --- a/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt
    > +++ b/Documentation/devicetree/bindings/watchdog/gpio-wdt.txt
    > @@ -13,6 +13,11 @@ Required Properties:
    > by the GPIO flags.
    > - hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds).
    >
    > +Optional Properties:
    > +- always-running: If the watchdog timer cannot be disabled, add this flag to
    > + have the driver keep toggling the signal without a client. It will only cease
    > + to toggle the signal when the device is open and the timeout elapsed.
    > +
    > Example:
    > watchdog: watchdog {
    > /* ADM706 */
    > diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
    > index 220a9e0..9bfbd73 100644
    > --- a/drivers/watchdog/gpio_wdt.c
    > +++ b/drivers/watchdog/gpio_wdt.c
    > @@ -31,6 +31,8 @@ struct gpio_wdt_priv {
    > int gpio;
    > bool active_low;
    > bool state;
    > + bool always_running;
    > + bool armed;
    > unsigned int hw_algo;
    > unsigned int hw_margin;
    > unsigned long last_jiffies;
    > @@ -48,10 +50,8 @@ static void gpio_wdt_disable(struct gpio_wdt_priv *priv)
    > gpio_direction_input(priv->gpio);
    > }
    >
    > -static int gpio_wdt_start(struct watchdog_device *wdd)
    > +static void gpio_wdt_start_impl(struct gpio_wdt_priv *priv)
    > {
    > - struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
    > -
    > priv->state = priv->active_low;
    > gpio_direction_output(priv->gpio, priv->state);
    > priv->last_jiffies = jiffies;
    > @@ -60,12 +60,25 @@ static int gpio_wdt_start(struct watchdog_device *wdd)
    > return 0;
    > }
    >
    > +static int gpio_wdt_start(struct watchdog_device *wdd)
    > +{
    > + struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
    > +
    > + gpio_wdt_start_impl(priv);
    > + priv->armed = true;
    > +
    > + return 0;
    > +}
    > +
    > static int gpio_wdt_stop(struct watchdog_device *wdd)
    > {
    > struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
    >
    > - mod_timer(&priv->timer, 0);
    > - gpio_wdt_disable(priv);
    > + priv->armed = false;
    > + if (!priv->always_running) {
    > + mod_timer(&priv->timer, 0);
    > + gpio_wdt_disable(priv);
    > + }
    >
    > return 0;
    > }
    > @@ -91,8 +104,8 @@ static void gpio_wdt_hwping(unsigned long data)
    > struct watchdog_device *wdd = (struct watchdog_device *)data;
    > struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
    >
    > - if (time_after(jiffies, priv->last_jiffies +
    > - msecs_to_jiffies(wdd->timeout * 1000))) {
    > + if (priv->armed && time_after(jiffies, priv->last_jiffies +
    > + msecs_to_jiffies(wdd->timeout * 1000))) {
    > dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n");
    > return;
    > }
    > @@ -197,6 +210,9 @@ static int gpio_wdt_probe(struct platform_device *pdev)
    > /* Use safe value (1/2 of real timeout) */
    > priv->hw_margin = msecs_to_jiffies(hw_margin / 2);
    >
    > + priv->always_running = of_property_read_bool(pdev->dev.of_node,
    > + "always-running");
    > +
    > watchdog_set_drvdata(&priv->wdd, priv);
    >
    > priv->wdd.info = &gpio_wdt_ident;
    > @@ -216,8 +232,15 @@ static int gpio_wdt_probe(struct platform_device *pdev)
    > priv->notifier.notifier_call = gpio_wdt_notify_sys;
    > ret = register_reboot_notifier(&priv->notifier);
    > if (ret)
    > - watchdog_unregister_device(&priv->wdd);
    > + goto error_unregister;
    >
    > + if (priv->always_running)
    > + gpio_wdt_start_impl(priv);
    > +
    > + return 0;
    > +
    > +error_unregister:
    > + watchdog_unregister_device(&priv->wdd);
    > return ret;
    > }
    >
    >



    Met vriendelijke groet / kind regards,

    Mike Looijmans
    System Expert


    TOPIC Embedded Systems
    Eindhovenseweg 32-C, NL-5683 KH Best
    Postbus 440, NL-5680 AK Best
    Telefoon: (+31) (0) 499 33 69 79
    Telefax: (+31) (0) 499 33 69 70
    E-mail: mike.looijmans@topic.nl
    Website: www.topic.nl

    Please consider the environment before printing this e-mail

    Topic zoekt gedreven (embedded) software specialisten!
    http://topic.nl/vacatures/topic-zoekt-software-engineers/



    \
     
     \ /
      Last update: 2014-12-11 08:41    [W:4.595 / U:0.376 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site