The syctr interrupt could set the affinity to any cores in the
SoC. However, the default affinity is set to cpu 0.
This timer will be used as broadcast timer on all the i.MX
SoCs. Because DYNIRQ flag is set, the core time framework will runtime
set the interrupt affinity to the cores that needs to wake up and the
cpumask will runtime set to the core that will be wake up. So even the
sysctr initialization use cpumask 0, there is no issue, the current
patch is just use cpu_possible_mask to show the fact that the timer
supports routed to all the cpu cores and nothing else.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20211201125030.2307746-2-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The variables 'sys_ctr_base' and 'cmpcr' are not be updated after
init, so mark them as __ro_after_init.
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20211201125030.2307746-1-peng.fan@oss.nxp.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The system counter block guide states that the base clock is
internally divided by 3 before use, that means the clock input of
system counter defined in DT should be base clock which is normally
from OSC, and then internally divided by 3 before use.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
The system counter (sys_ctr) is a programmable system counter
which provides a shared time base to the Cortex A15, A7, A53 etc cores.
It is intended for use in applications where the counter is always
powered on and supports multiple, unrelated clocks. The sys_ctr hardware
supports:
- 56-bit counter width (roll-over time greater than 40 years)
- compare frame(64-bit compare value) contains programmable interrupt
generation when compare value <= counter value.
[dlezcano] Fixed over 80 chars length warning
Signed-off-by: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Peng Fan