Commit Graph

4 Commits

Author SHA1 Message Date
Peter Maydell
b7cd9c1e84 clock: Define and use new clock_display_freq()
It's common to want to print a human-readable indication of a clock's
frequency. Provide a utility function in the clock API to return a
string which is a displayable representation of the frequency,
and use it in qdev-monitor.c.

Before:

  (qemu) info qtree
  [...]
  dev: xilinx,zynq_slcr, id ""
    clock-in "ps_clk" freq_hz=3.333333e+07
    mmio 00000000f8000000/0000000000001000

After:

  dev: xilinx,zynq_slcr, id ""
    clock-in "ps_clk" freq_hz=33.3 MHz
    mmio 00000000f8000000/0000000000001000

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201215150929.30311-5-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2021-01-04 23:24:44 +01:00
Peter Maydell
de6a65f11d clock: Remove clock_get_ns()
Remove the now-unused clock_get_ns() API and the CLOCK_PERIOD_TO_NS()
macro that only it was using.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201215150929.30311-4-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2021-01-04 23:24:44 +01:00
Peter Maydell
554d523785 clock: Introduce clock_ticks_to_ns()
The clock_get_ns() API claims to return the period of a clock in
nanoseconds. Unfortunately since it returns an integer and a
clock's period is represented in units of 2^-32 nanoseconds,
the result is often an approximation, and calculating a clock
expiry deadline by multiplying clock_get_ns() by a number-of-ticks
is unacceptably inaccurate.

Introduce a new API clock_ticks_to_ns() which returns the number
of nanoseconds it takes the clock to make a given number of ticks.
This function can do the complete calculation internally and
will thus give a more accurate result.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201215150929.30311-2-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2021-01-04 23:24:44 +01:00
Peter Maydell
31e5784a0d docs/clocks: add device's clock documentation
Add the documentation about the clock inputs and outputs in devices.

This is based on the original work of Frederic Konrad.

Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20200406135251.157596-6-damien.hedde@greensocs.com
[PMM: Editing pass for minor grammar, style and Sphinx
 formatting fixes]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-04-30 15:35:40 +01:00