Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
On Wed, Nov 11, 2020 at 03:15:17PM +, Vaittinen, Matti wrote: [ ... ] > > > > + > > > > + priv->wdd.info = _wdt_ident; > > > > + priv->wdd.ops = _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. > > > > > > > Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified, > > it can and should be a reasonable constant (like the usual 30 > > seconds). > > It does not and should not be bound by max_hw_heartbeat_ms. > > Thanks for confirming this Guenter. I'd better admit I didn't > understand how the max_hw_heartbeat_ms works. > > If I now read the code correctly, the "watchdog worker" takes care of > feeding for shorter periods than the "timeout" - and only stops > feeding max_hw_heartbeat_ms before timeout expires if userland has not > been feedin wdg. This is really cool approach for short(ish) > max_hw_heartbeat_ms configurations as user-space does not need to meet > "RT requirements". WDG framework is much more advanced that I knew :) Yes, exactly, that is the idea. Various drivers used to implement this within the driver, so it just made sense to pull the functionality into the watchdog core. Thanks, Guenter
Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
On Wed, 2020-11-11 at 06:41 -0800, Guenter Roeck wrote:
> On 11/11/20 6:01 AM, Vaittinen, Matti wrote:
> > 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 > > >
> > > Reviewed-by: Guenter Roeck
> > > ---
> > >
> >
> > //snip
> >
> > > + ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
> > > ms",
> > > + _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(>wdd, priv);
> > > +
> > > + priv->wdd.info = _wdt_ident;
> > > + priv->wdd.ops = _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.
> >
>
> Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified,
> it can and should be a reasonable constant (like the usual 30
> seconds).
> It does not and should not be bound by max_hw_heartbeat_ms.
Thanks for confirming this Guenter. I'd better admit I didn't
understand how the max_hw_heartbeat_ms works.
If I now read the code correctly, the "watchdog worker" takes care of
feeding for shorter periods than the "timeout" - and only stops
feeding max_hw_heartbeat_ms before timeout expires if userland has not
been feedin wdg. This is really cool approach for short(ish)
max_hw_heartbeat_ms configurations as user-space does not need to meet
"RT requirements". WDG framework is much more advanced that I knew :)
It's nice to learn!
--Matti
Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
On 11/11/20 6:01 AM, Vaittinen, Matti wrote:
> 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
>> Reviewed-by: Guenter Roeck
>> ---
>>
>
> //snip
>
>> +ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
>> ms",
>> + _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(>wdd, priv);
>> +
>> +priv->wdd.info = _wdt_ident;
>> +priv->wdd.ops = _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.
>
Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified,
it can and should be a reasonable constant (like the usual 30 seconds).
It does not and should not be bound by max_hw_heartbeat_ms.
> 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...
>
No worries. Thanks for noticing.
Guenter
> --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)
>
Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
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
> Reviewed-by: Guenter Roeck
> ---
>
//snip
> + ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
> ms",
> + _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(>wdd, priv);
> +
> + priv->wdd.info = _wdt_ident;
> + priv->wdd.ops = _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)
[PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
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
Reviewed-by: Guenter Roeck
---
drivers/watchdog/Kconfig | 13 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/bd9576_wdt.c | 290 ++
3 files changed, 304 insertions(+)
create mode 100644 drivers/watchdog/bd9576_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index fd7968635e6d..d5fec1bdf23e 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -172,6 +172,19 @@ config BD70528_WATCHDOG
Alternatively say M to compile the driver as a module,
which will be called bd70528_wdt.
+config BD957XMUF_WATCHDOG
+ tristate "ROHM BD9576MUF and BD9573MUF PMIC Watchdog"
+ depends on MFD_ROHM_BD957XMUF
+ select WATCHDOG_CORE
+ help
+ Support for the watchdog in the ROHM BD9576 and BD9573 PMICs.
+ These PMIC ICs contain watchdog block which can be configured
+ to toggle reset line if SoC fails to ping watchdog via GPIO.
+
+ Say Y here to include support for the ROHM BD9576 or BD9573
+ watchdog. Alternatively say M to compile the driver as a module,
+ which will be called bd9576_wdt.
+
config DA9052_WATCHDOG
tristate "Dialog DA9052 Watchdog"
depends on PMIC_DA9052 || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 071a2e50be98..54f39883f3ac 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -209,6 +209,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o
# Architecture Independent
obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o
+obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o
obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
diff --git a/drivers/watchdog/bd9576_wdt.c b/drivers/watchdog/bd9576_wdt.c
new file mode 100644
index ..afef19ce01be
--- /dev/null
+++ b/drivers/watchdog/bd9576_wdt.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 ROHM Semiconductors
+ *
+ * ROHM BD9576MUF and BD9573MUF Watchdog driver
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+static bool nowayout;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default=\"false\")");
+
+#define HW_MARGIN_MIN 2
+#define HW_MARGIN_MAX 4416
+#define BD957X_WDT_DEFAULT_MARGIN 4416
+
+struct bd9576_wdt_priv {
+ struct gpio_desc*gpiod_ping;
+ struct gpio_desc*gpiod_en;
+ struct device *dev;
+ struct regmap *regmap;
+ boolalways_running;
+ struct watchdog_device wdd;
+};
+
+static void bd9576_wdt_disable(struct bd9576_wdt_priv *priv)
+{
+ gpiod_set_value_cansleep(priv->gpiod_en, 0);
+}
+
+static int bd9576_wdt_ping(struct watchdog_device *wdd)
+{
+ struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ /* Pulse */
+ gpiod_set_value_cansleep(priv->gpiod_ping, 1);
+ gpiod_set_value_cansleep(priv->gpiod_ping, 0);
+
+ return 0;
+}
+
+static int bd9576_wdt_start(struct watchdog_device *wdd)
+{
+ struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ gpiod_set_value_cansleep(priv->gpiod_en, 1);
+
+ return bd9576_wdt_ping(wdd);
+}
+
+static int bd9576_wdt_stop(struct watchdog_device *wdd)
+{
+ struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+ if (!priv->always_running)
+ bd9576_wdt_disable(priv);
+ else
+ set_bit(WDOG_HW_RUNNING, >status);
+
+ return 0;
+}
+
+static const struct watchdog_info bd957x_wdt_ident = {
+ .options= WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
+ WDIOF_SETTIMEOUT,
+ .identity = "BD957x Watchdog",
+};
+
+static const struct watchdog_ops bd957x_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = bd9576_wdt_start,
+ .stop = bd9576_wdt_stop,
+ .ping = bd9576_wdt_ping,
+};
+
+/* Unit is hundreds of uS */
+#define FASTNG_MIN 23
+
+static int find_closest_fast(int target, int *sel, int *val)
+{
+ int i;
+ int window = FASTNG_MIN;
+
+ for (i = 0; i < 8 && window < target; i++)
+ window <<= 1;
+
+ *val = window;
+ *sel = i;
+
+ if (i == 8)
+ return -EINVAL;
+
+ return 0;
+
+}
+
+static int find_closest_slow_by_fast(int fast_val, int
