Commit Graph

27 Commits

Author SHA1 Message Date
Wolfram Sang
e007372bfb watchdog: renesas_wdt: add grace period before rebooting
arm64 does not have a grace period after calling reset handlers. It is
rightfully assumed that watchdog drivers should wait because they know
the time needed. Implement this for the Renesas watchdog driver.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@oeck-us.net>
Link: https://lore.kernel.org/r/20210118094558.36814-1-wsa+renesas@sang-engineering.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-02-07 14:41:22 +01:00
Wolfram Sang
fa01fa7003 watchdog: renesas_wdt: don't sleep in atomic context
In the restart handler, we hit multiple OOPSes. One because of
usleep_range() and one because of RPM. So, instead of re-using
rwdt_start(), we implement an atomic version of it in the restart
handler. As a little bonus, reboot will occur sooner because we can now
use the smallest divider in the custom restart routine.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20201219173415.21848-1-wsa+renesas@sang-engineering.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2021-02-07 14:41:19 +01:00
Wolfram Sang
962085a2bb watchdog: renesas_wdt: support handover from bootloader
Support an already running watchdog by checking its enable bit and set
up the status accordingly before registering the device.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200908095615.31376-1-wsa+renesas@sang-engineering.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2020-10-14 15:22:56 +02:00
Yoshihiro Shimoda
b836005b4f watchdog: renesas_wdt: Add a few cycles delay
According to the hardware manual of R-Car Gen2 and Gen3,
software should wait a few RLCK cycles as following:
 - Delay 2 cycles before setting watchdog counter.
 - Delay 3 cycles before disabling module clock.

So, this patch adds such delays.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08 19:39:44 +02:00
Hoan Nguyen An
b7fbd3e55c watchdog: renesas_wdt: Use 'dev' instead of dereferencing it repeatedly
Add helper variable dev = &pdev->dev

Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08 16:10:11 +02:00
Wolfram Sang
cd6457a925 watchdog: renesas_wdt: drop warning after calling watchdog_init_timeout
The core will print out details now.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-05 21:08:31 +02:00
Wolfram Sang
e184312649 watchdog: renesas_wdt: drop superfluous glob pattern
If we want to match all revisions, it is enough to leave the field
empty.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-05 21:04:58 +02:00
Guenter Roeck
0f0a6a285e watchdog: Convert to use devm_platform_ioremap_resource
Use devm_platform_ioremap_resource to reduce source code size,
improve readability, and reduce the likelyhood of bugs.

The conversion was done automatically with coccinelle using the
following semantic patch.

@r@
identifier res, pdev;
expression a;
expression index;
expression e;
@@

<+...
- res = platform_get_resource(pdev, IORESOURCE_MEM, index);
- a = devm_ioremap_resource(e, res);
+ a = devm_platform_ioremap_resource(pdev, index);
...+>

@depends on r@
identifier r.res;
@@
- struct resource *res;
  ... when != res

@@
identifier res, pdev;
expression index;
expression a;
@@
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, index);
- a = devm_ioremap_resource(&pdev->dev, res);
+ a = devm_platform_ioremap_resource(pdev, index);

Cc: Joel Stanley <joel@jms.id.au>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Avi Fishman <avifishman70@gmail.com>
Cc: Nancy Yuen <yuenn@google.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Michal Simek <michal.simek@xilinx.com> (cadence/xilinx wdts)
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-05 21:02:12 +02:00
Wolfram Sang
9077123c68 watchdog: renesas_wdt: don't keep timer value during suspend/resume
After discussing this mail thread [1] again, we concluded that giving
userspace enough time to prepare is our favourite option. So, do not
keep the time value when suspended but reset it when resuming.

[1] https://patchwork.kernel.org/patch/10252209/

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-12-22 12:15:32 +01:00
Wolfram Sang
e990e12741 watchdog: renesas_wdt: don't set divider while watchdog is running
The datasheet says we must stop the timer before changing the clock
divider. This can happen when the restart handler is called while the
watchdog is running.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-12-09 15:03:27 +01:00
Fabrizio Castro
f8cde72673 watchdog: renesas_wdt: Fix typos
Do not use "," but ";" to separate instructions.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-11-17 09:53:26 +01:00
Wolfram Sang
14de99b44b watchdog: renesas_wdt: stop when unregistering
We want to go into a sane state when unregistering. Currently, it
happens that the watchdog stops when unbinding because of RuntimePM
stopping the core clock. When rebinding, the core clock gets reactivated
and the watchdog fires even though it hasn't been opened by userspace
yet. Strange scenario, yes, but sane state is much preferred anyhow.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-10-02 13:32:24 +02:00
Wolfram Sang
3bed02a296 watchdog: renesas_wdt: use SPDX identifier for Renesas drivers
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-10-02 13:32:23 +02:00
Geert Uytterhoeven
665f94423a watchdog: renesas-wdt: Remove R-Car M2-W ES2.x from blacklist
System restart triggered by watchdog time-out works fine on a Koelsch
board with R-Car M2-W ES2.0.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2018-05-21 21:24:41 +02:00
Veeraiyan Chidambaram
fdac6a90d2 watchdog: renesas-wdt: Add support for WDIOF_CARDRESET
This patch adds the WDIOF_CARDRESET support for the Renesas platform
watchdog, to know if the board reboot is due to a watchdog reset.

This is done via the WOVF bit (bit 4) of the RWTCSRA register, which
indicates if RWTCNT overflowed, triggering the reset in last boot.

Signed-off-by: Veeraiyan Chidambaram <veeraiyan.chidambaram@in.bosch.com>
[takeshi.kihara.df: changed to read the RWTCSRA register while clock is
 enabled]
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2018-04-16 10:22:40 +02:00
Fabrizio Castro
089bcaa87e watchdog: renesas_wdt: Add restart handler
On iWave's boards iwg20d and iwg22d the only way to reboot the system is
by means of the watchdog.
This patch adds a restart handler to rwdt_ops, and also makes sure we
keep its priority to the lowest level, in order to not override other
more effective handlers.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2018-03-10 11:45:35 +01:00
Fabrizio Castro
3fe95e6c68 watchdog: renesas_wdt: Add R-Car Gen2 support
Due to commits:
* "ARM: shmobile: Add watchdog support",
* "ARM: shmobile: rcar-gen2: Add watchdog support", and
* "soc: renesas: rcar-rst: Enable watchdog as reset trigger for Gen2",
we now have everything we needed for the watchdog to work on Gen2 and
RZ/G1.

However, on early revisions of some R-Car Gen2 SoCs, and depending on SMP
configuration, the system may fail to restart on watchdog time-out, and
lock up instead.

Specifically:
  - On R-Car H2 ES1.0 and M2-W ES1.0, watchdog restart fails unless
    only the first CPU core is in use (using e.g. the "maxcpus=1" kernel
    commandline option).
  - On R-Car V2H ES1.1, watchdog restart fails unless SMP is disabled
    completely (using CONFIG_SMP=n during build configuration, or using
    the "nosmp" or "maxcpus=0" kernel commandline options).

This commit adds "renesas,rcar-gen2-wdt" as compatible string for R-Car
Gen2 and RZ/G1, but also prevents the system from using the watchdog
driver in cases where the system would fail to restart by blacklisting
the affected SoCs, using the minimum known working revisions (ES2.0 on R-Car
H2, and ES3.0 on M2-W), and taking the actual SMP software configuration
into account.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
[Geert: blacklisting logic]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2018-03-10 11:45:34 +01:00
Fabrizio Castro
07278ca1cc watchdog: renesas_wdt: Add suspend/resume support
On R-Car Gen2 and RZ/G1 the watchdog IP clock needs to be always ON,
on R-Car Gen3 we power the IP down during suspend.

This commit adds suspend/resume support, so that the watchdog counting
"pauses" during suspend on all of the SoCs compatible with this driver
and on those we are now adding support for (R-Car Gen2 and RZ/G1).

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2018-03-10 11:45:34 +01:00
Wolfram Sang
1f185596e7 watchdog: renesas_wdt: update copyright dates
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 21:11:58 +02:00
Wolfram Sang
9c22b6d336 watchdog: renesas_wdt: make 'clk' a variable local to probe()
It is not needed outside probe() anymore.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 21:11:55 +02:00
Wolfram Sang
3be42941dd watchdog: renesas_wdt: consistently use RuntimePM for clock management
On Renesas R-Car archs, RuntimePM does all the clock handling. So, use
it consistently to enable/disable the clocks. Also make sure that clocks
are really enabled around clk_get_rate(). clk_summary looks proper now:

		clock	enable_cnt	prepare_cnt	rate ...
Before this commit:

At boot:	rwdt	1		1		32768 0 0
WDT running:	rwdt	2		2		32768 0 0

After this commit:

At boot:	rwdt	0		1		32768 0 0
WDT running	rwdt	1		1		32768 0 0

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 21:11:52 +02:00
Wolfram Sang
03a196f25f watchdog: renesas_wdt: add another divider option
If we set RWTCSRB to 0, we can gain 4096 as another divider value. This
is supported by all R-Car Gen2 and Gen3 devices which we aim to support.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 20:23:24 +02:00
Wolfram Sang
82f64cd208 watchdog: renesas_wdt: apply better precision
The error margin of the clks_per_second variable was too large and
caused offsets when used with clock frequencies which left a remainder
after applying the dividers. Now we always calculate directly using the
clock rate and the divider using some helper macros. That also means
that DIV_ROUND_UP moves from probe to the multiplication macro. In
probe, we don't need to ensure anymore that 'clks_per_sec' would go too
fast but rather ensure that the lower limit is really at least 1 to
certainly get a full cycle.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 20:23:19 +02:00
Wolfram Sang
1c1b243401 watchdog: renesas_wdt: don't round closest with get_timeleft
We should never return more time left than there actually is. So, switch
to a plain divider instead of DIV_ROUND_CLOSEST.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 20:23:14 +02:00
Wolfram Sang
b51247c802 watchdog: renesas_wdt: check rate also for upper limit
When checking the clock rate, ensure also that counting all 16 bits
takes at least one second to match the granularity of the framework.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 20:23:08 +02:00
Wolfram Sang
f6159dd4b0 watchdog: renesas_wdt: avoid (theoretical) type overflow
Because the smallest clock divider we can select is 1, 'clks_per_sec'
must be the same type as 'rate'.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 20:23:00 +02:00
Wolfram Sang
bd99b68ed7 watchdog: renesas-wdt: add driver
Add support for watchdogs (RWDT and SWDT) found on RCar Gen3 based SoCs
from Renesas.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-05-14 18:15:40 +02:00