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path: root/drivers/watchdog/renesas_wdt.c
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2018-05-21watchdog: renesas-wdt: Remove R-Car M2-W ES2.x from blacklistGeert Uytterhoeven1-1/+1
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 Chidambaram1-2/+4
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 Castro1-0/+12
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 Castro1-5/+44
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 Castro1-0/+26
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 Sang1-2/+2
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 Sang1-5/+5
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 Sang1-14/+19
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 Sang1-3/+5
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 Sang1-9/+19
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 Sang1-1/+1
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 Sang1-2/+2
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 Sang1-3/+2
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 Sang1-0/+213
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>