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path: root/drivers/clocksource/timer-ti-dm-systimer.c
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2022-02-18ARM: dts: Use 32KiHz oscillator on devkit8000Anthoine Bourgeois
Devkit8000 board seems to always used 32k_counter as clocksource. Restore this behavior. If clocksource is back to 32k_counter, timer12 is now the clockevent source (as before) and timer2 is not longer needed here. This commit fixes the same issue observed with commit 23885389dbbb ("ARM: dts: Fix timer regression for beagleboard revision c") when sleep is blocked until hitting keys over serial console. Fixes: aba1ad05da08 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support") Fixes: e428e250fde6 ("ARM: dts: Configure system timers for omap3") Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2021-12-17ARM: dts: Fix timer regression for beagleboard revision cTony Lindgren
Commit e428e250fde6 ("ARM: dts: Configure system timers for omap3") caused a timer regression for beagleboard revision c where the system clockevent stops working if omap3isp module is unloaded. Turns out we still have beagleboard revisions a-b4 capacitor c70 quirks applied that limit the usable timers for no good reason. This also affects the power management as we use the system clock instead of the 32k clock source. Let's fix the issue by adding a new omap3-beagle-ab4.dts for the old timer quirks. This allows us to remove the timer quirks for later beagleboard revisions. We also need to update the related timer quirk check for the correct compatible property. Fixes: e428e250fde6 ("ARM: dts: Configure system timers for omap3") Cc: linux-kernel@vger.kernel.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <robh+dt@kernel.org> Reported-by: Jarkko Nikula <jarkko.nikula@bitmer.com> Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2021-04-08clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940Tony Lindgren
There is a timer wrap issue on dra7 for the ARM architected timer. In a typical clock configuration the timer fails to wrap after 388 days. To work around the issue, we need to use timer-ti-dm percpu timers instead. Let's configure dmtimer3 and 4 as percpu timers by default, and warn about the issue if the dtb is not configured properly. Let's do this as a single patch so it can be backported to v5.8 and later kernels easily. Note that this patch depends on earlier timer-ti-dm systimer posted mode fixes, and a preparatory clockevent patch "clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue". For more information, please see the errata for "AM572x Sitara Processors Silicon Revisions 1.1, 2.0": https://www.ti.com/lit/er/sprz429m/sprz429m.pdf The concept is based on earlier reference patches done by Tero Kristo and Keerthy. Cc: Keerthy <j-keerthy@ti.com> Cc: Tero Kristo <kristo@kernel.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210323074326.28302-3-tony@atomide.com
2021-04-08clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issueTony Lindgren
There is a timer wrap issue on dra7 for the ARM architected timer. In a typical clock configuration the timer fails to wrap after 388 days. To work around the issue, we need to use timer-ti-dm timers instead. Let's prepare for adding support for percpu timers by adding a common dmtimer_clkevt_init_common() and call it from dmtimer_clockevent_init(). This patch makes no intentional functional changes. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210323074326.28302-2-tony@atomide.com
2021-04-08clocksource/drivers/timer-ti-dm: Add missing set_state_oneshot_stoppedTony Lindgren
To avoid spurious timer interrupts when KTIME_MAX is used, we need to configure set_state_oneshot_stopped(). Although implementing this is optional, it still affects things like power management for the extra timer interrupt. For more information, please see commit 8fff52fd5093 ("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state") and commit cf8c5009ee37 ("clockevents/drivers/arm_arch_timer: Implement ->set_state_oneshot_stopped()"). Fixes: 52762fbd1c47 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support") Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210304072135.52712-4-tony@atomide.com
2021-04-08clocksource/drivers/timer-ti-dm: Fix posted mode status check orderTony Lindgren
When the timer is configured in posted mode, we need to check the write- posted status register (TWPS) before writing to the register. We now check TWPS after the write starting with commit 52762fbd1c47 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support"). For example, in the TRM for am571x the following is documented in chapter "22.2.4.13.1.1 Write Posting Synchronization Mode": "For each register, a status bit is provided in the timer write-posted status (TWPS) register. In this mode, it is mandatory that software check this status bit before any write access. If a write is attempted to a register with a previous access pending, the previous access is discarded without notice." The regression happened when I updated the code to use standard read/write accessors for the driver instead of using __omap_dm_timer_load_start(). We have__omap_dm_timer_load_start() check the TWPS status correctly using __omap_dm_timer_write(). Fixes: 52762fbd1c47 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support") Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210304072135.52712-2-tony@atomide.com
2021-03-22timekeeping, clocksource: Fix various typos in commentsIngo Molnar
Fix ~56 single-word typos in timekeeping & clocksource code comments. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-kernel@vger.kernel.org
2020-08-24clocksource/drivers/timer-ti-dm: Do reset before enableTony Lindgren
Commit 6cfcd5563b4f ("clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4") exposed a new issue for type2 dual mode timers on at least omap5 where the clockevent will stop when the SoC starts entering idle states during the boot. Turns out we are wrongly first enabling the system timer and then resetting it, while we must also re-enable it after reset. The current sequence leaves the timer module in a partially initialized state. This issue went unnoticed earlier with ti-sysc driver reconfiguring the timer module until we fixed the issue of ti-sysc reconfiguring system timers. Let's fix the issue by calling dmtimer_systimer_enable() from reset for both type1 and type2 timers, and switch the order of reset and enable in dmtimer_systimer_setup(). Let's also move dmtimer_systimer_enable() and dmtimer_systimer_disable() to do this without adding forward declarations. Fixes: 6cfcd5563b4f ("clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4") Reported-by: H. Nikolaus Schaller" <hns@goldelico.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200817092428.6176-1-tony@atomide.com
2020-07-21clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4Tony Lindgren
Carlos Hernandez <ceh@ti.com> reported that we now have a suspend and resume regresssion on am3 and am4 compared to the earlier kernels. While suspend and resume works with v5.8-rc3, we now get errors with rtcwake: pm33xx pm33xx: PM: Could not transition all powerdomains to target state ... rtcwake: write error This is because we now fail to idle the system timer clocks that the idle code checks and the error gets propagated to the rtcwake. Turns out there are several issues that need to be fixed: 1. Ignore no-idle and no-reset configured timers for the ti-sysc interconnect target driver as otherwise it will keep the system timer clocks enabled 2. Toggle the system timer functional clock for suspend for am3 and am4 (but not for clocksource on am3) 3. Only reconfigure type1 timers in dmtimer_systimer_disable() 4. Use of_machine_is_compatible() instead of of_device_is_compatible() for checking the SoC type Fixes: 52762fbd1c47 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support") Reported-by: Carlos Hernandez <ceh@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Carlos Hernandez <ceh@ti.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200713162601.6829-1-tony@atomide.com
2020-05-23clocksource/drivers/timer-ti-dm: Fix spelling mistake "detectt" -> "detect"Colin Ian King
There is a spelling mistake in a pr_err message. Fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200519224428.6195-1-colin.king@canonical.com
2020-05-23clocksource/drivers/timer-ti-dm: Fix warning for set but not usedTony Lindgren
We can get a warning for dmtimer_clocksource_init() with 'pa' set but not used. This was used in the earlier revisions of the code but no longer needed, so let's remove the unused pa and of_translate_address(). Let's also do it for dmtimer_clockevent_init() that has a similar issue. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200519155157.12804-1-tony@atomide.com
2020-05-23clocksource/drivers/timer-ti-dm: Add clockevent and clocksource supportTony Lindgren
We can move the TI dmtimer clockevent and clocksource to live under drivers/clocksource if we rely only on the clock framework, and handle the module configuration directly in the clocksource driver based on the device tree data. This removes the early dependency with system timers to the interconnect related code, and we can probe pretty much everything else later on at the module_init level. Let's first add a new driver for timer-ti-dm-systimer based on existing arch/arm/mach-omap2/timer.c. Then let's start moving SoCs to probe with device tree data while still keeping the old timer.c. And eventually we can just drop the old timer.c. Let's take the opportunity to switch to use readl/writel as pointed out by Daniel Lezcano <daniel.lezcano@linaro.org>. This allows further clean-up of the timer-ti-dm code the a lot of the shared helpers can just become static to the non-syster related code. Note the boards can optionally configure different timer source clocks if needed with assigned-clocks and assigned-clock-parents. Cc: linux-kernel@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Keerthy <j-keerthy@ti.com> Cc: Lokesh Vutla <lokeshvutla@ti.com> Cc: Rob Herring <robh@kernel.org> Cc: Tero Kristo <t-kristo@ti.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20200507172330.18679-3-tony@atomide.com