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path: root/drivers/watchdog/renesas_wdt.c
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2021-02-07watchdog: renesas_wdt: add grace period before rebootingWolfram Sang
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>
2021-02-07watchdog: renesas_wdt: don't sleep in atomic contextWolfram Sang
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>
2020-10-14watchdog: renesas_wdt: support handover from bootloaderWolfram Sang
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>
2019-07-08watchdog: renesas_wdt: Add a few cycles delayYoshihiro Shimoda
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>
2019-07-08watchdog: renesas_wdt: Use 'dev' instead of dereferencing it repeatedlyHoan Nguyen An
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>
2019-05-05watchdog: renesas_wdt: drop warning after calling watchdog_init_timeoutWolfram Sang
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>
2019-05-05watchdog: renesas_wdt: drop superfluous glob patternWolfram Sang
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>
2019-05-05watchdog: Convert to use devm_platform_ioremap_resourceGuenter Roeck
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>
2018-12-22watchdog: renesas_wdt: don't keep timer value during suspend/resumeWolfram Sang
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>
2018-12-09watchdog: renesas_wdt: don't set divider while watchdog is runningWolfram Sang
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>
2018-11-17watchdog: renesas_wdt: Fix typosFabrizio Castro
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>
2018-10-02watchdog: renesas_wdt: stop when unregisteringWolfram Sang
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>
2018-10-02watchdog: renesas_wdt: use SPDX identifier for Renesas driversWolfram Sang
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>
2018-05-21watchdog: renesas-wdt: Remove R-Car M2-W ES2.x from blacklistGeert Uytterhoeven
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>
2018-04-16watchdog: renesas-wdt: Add support for WDIOF_CARDRESETVeeraiyan Chidambaram
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>
2018-03-10watchdog: renesas_wdt: Add restart handlerFabrizio Castro
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>
2018-03-10watchdog: renesas_wdt: Add R-Car Gen2 supportFabrizio Castro
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>
2018-03-10watchdog: renesas_wdt: Add suspend/resume supportFabrizio Castro
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>
2017-09-09watchdog: renesas_wdt: update copyright datesWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: make 'clk' a variable local to probe()Wolfram Sang
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>
2017-09-09watchdog: renesas_wdt: consistently use RuntimePM for clock managementWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: add another divider optionWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: apply better precisionWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: don't round closest with get_timeleftWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: check rate also for upper limitWolfram Sang
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>
2017-09-09watchdog: renesas_wdt: avoid (theoretical) type overflowWolfram Sang
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>
2016-05-14watchdog: renesas-wdt: add driverWolfram Sang
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>
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