On 15/11/2018 23:46, Martin Blumenstingl wrote: > While trying to add support for the ARM TWD Timer and the ARM Global > Timer on Meson8, Meson8b and Meson8m2 (ARM Cortex-A5 and Cortex-A9 SoCs) > I did a review of the existing driver. > Unfortunately I found it hard to review because the pre-processor > #defines did not match the names from the public S805 datasheet. Thus > patch #1 adjusts these. No functional changes here, this is just > preparation work for patch #2. > > Using the ARM Global Timer (drivers/clocksource/arm_global_timer.c) > would have given us a timer-based delay implementation (so udelay() and > friends would use the timer instead of using a loop-based delay > implementation). Unfortunately we can't use the ARM Global Timer yet > because it's input clock is derived from the CPU clock (which can change > once we enable CPU frequency scaling on these SoCs, for which I will be > sending patches in the near future). > Amlogic's 3.10 kernel uses Timer E as delay timer which (with the > current configuration) has a resolution of 1us. So patch #2 uses > register_current_timer_delay() to register Timer E as ARM delay timer > (which will be especially useful as we have to use udelay() when > changing the CPU clocks during DVFS). > > > Changes since v1 at [0]: > - convert the enums for the input clock (meson6_timera_input_clock and > meson6_timere_input_clock) to simple #defines as these are register > values and not something driver-internal. All other register values > are #defines so it makes sense that these are #defines as well. > > > [0] https://patchwork.kernel.org/cover/10658591/ > > > Martin Blumenstingl (2): > clocksource: meson6_timer: use register names from the datasheet > clocksource: meson6_timer: implement ARM delay timer > > drivers/clocksource/meson6_timer.c | 128 +++++++++++++++++++---------- > 1 file changed, 85 insertions(+), 43 deletions(-)
Both applied, thanks! -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
