Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
From: Vaittinen, Matti <hidden>
Date: 2020-11-11 14:01:50
Also in:
linux-watchdog, lkml
On Thu, 2020-11-05 at 13:38 +0200, Matti Vaittinen wrote:
Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are mainly used to power the R-Car series processors. The watchdog is pinged using a GPIO and enabled using another GPIO. Additionally watchdog time-out can be configured to HW prior starting the watchdog. Watchdog timeout can be configured to detect only delayed ping or in a window mode where also too fast pings are detected. Signed-off-by: Matti Vaittinen <redacted> Reviewed-by: Guenter Roeck <linux@roeck-us.net> ---
//snip
+ ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
ms",
+ &hw_margin[0], 1, 2);
+ if (ret < 0 && ret != -EINVAL)
+ return ret;
+
+ if (ret == 1)
+ hw_margin_max = hw_margin[0];
+
+ if (ret == 2) {
+ hw_margin_max = hw_margin[1];
+ hw_margin_min = hw_margin[0];
+ }
+
+ ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min);
+ if (ret)
+ return ret;
+
+ priv->always_running = of_property_read_bool(np, "always-
running");
+
+ watchdog_set_drvdata(&priv->wdd, priv);
+
+ priv->wdd.info = &bd957x_wdt_ident;
+ priv->wdd.ops = &bd957x_wdt_ops;
+ priv->wdd.min_hw_heartbeat_ms = hw_margin_min;
+ priv->wdd.max_hw_heartbeat_ms = hw_margin_max;
+ priv->wdd.parent = dev;
+ priv->wdd.timeout = (hw_margin_max / 2) * 1000;Hmm. Just noticed this value does not make sense, right? Maximum hw_margin is 4416 ms. If I read this correctly timeout should be in seconds - so result is around 2 000 000 seconds here. I think it is useless value... Perhaps priv->wdd.timeout = (hw_margin_max / 2) / 1000; if (!priv->wdd.timeout) priv->wdd.timeout = 1; would be more appropriate. I need to do some testing when I get the HW at my hands - please don't apply this patch just yet. I will respin this after some testing - or if other patches are applied then I will just send this one alone. Sorry for the hassle... --Matti -- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. "non cogito me" dixit Rene Descarte, deinde evanescavit (Thanks for the translation Simon)