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[PULL 21/35] clock: Remove clock_get_ns()
From: |
Philippe Mathieu-Daudé |
Subject: |
[PULL 21/35] clock: Remove clock_get_ns() |
Date: |
Sun, 3 Jan 2021 21:50:07 +0100 |
From: Peter Maydell <peter.maydell@linaro.org>
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>
---
docs/devel/clocks.rst | 17 +++++++++++++----
include/hw/clock.h | 6 ------
2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/docs/devel/clocks.rst b/docs/devel/clocks.rst
index c2e70e64db1..2d317ff32f2 100644
--- a/docs/devel/clocks.rst
+++ b/docs/devel/clocks.rst
@@ -238,8 +238,17 @@ object during device instance init. For example:
Fetching clock frequency/period
-------------------------------
-To get the current state of a clock, use the functions ``clock_get()``,
-``clock_get_ns()`` or ``clock_get_hz()``.
+To get the current state of a clock, use the functions ``clock_get()``
+or ``clock_get_hz()``.
+
+``clock_get()`` returns the period of the clock in its fully precise
+internal representation, as an unsigned 64-bit integer in units of
+2^-32 nanoseconds. (For many purposes ``clock_ticks_to_ns()`` will
+be more convenient; see the section below on expiry deadlines.)
+
+``clock_get_hz()`` returns the frequency of the clock, rounded to the
+next lowest integer. This implies some inaccuracy due to the rounding,
+so be cautious about using it in calculations.
It is also possible to register a callback on clock frequency changes.
Here is an example:
@@ -254,8 +263,8 @@ Here is an example:
*/
/* do something with the new period */
- fprintf(stdout, "device new period is %" PRIu64 "ns\n",
- clock_get_ns(dev->my_clk_input));
+ fprintf(stdout, "device new period is %" PRIu64 "* 2^-32 ns\n",
+ clock_get(dev->my_clk_input));
}
Calculating expiry deadlines
diff --git a/include/hw/clock.h b/include/hw/clock.h
index b5fff6ded83..852c636961e 100644
--- a/include/hw/clock.h
+++ b/include/hw/clock.h
@@ -40,7 +40,6 @@ typedef void ClockCallback(void *opaque);
* macro helpers to convert to hertz / nanosecond
*/
#define CLOCK_PERIOD_FROM_NS(ns) ((ns) * (CLOCK_PERIOD_1SEC / 1000000000llu))
-#define CLOCK_PERIOD_TO_NS(per) ((per) / (CLOCK_PERIOD_1SEC / 1000000000llu))
#define CLOCK_PERIOD_FROM_HZ(hz) (((hz) != 0) ? CLOCK_PERIOD_1SEC / (hz) : 0u)
#define CLOCK_PERIOD_TO_HZ(per) (((per) != 0) ? CLOCK_PERIOD_1SEC / (per) : 0u)
@@ -215,11 +214,6 @@ static inline unsigned clock_get_hz(Clock *clk)
return CLOCK_PERIOD_TO_HZ(clock_get(clk));
}
-static inline unsigned clock_get_ns(Clock *clk)
-{
- return CLOCK_PERIOD_TO_NS(clock_get(clk));
-}
-
/**
* clock_ticks_to_ns:
* @clk: the clock to query
--
2.26.2
- [PULL 11/35] vt82c686: Split off via-[am]c97 into separate file in hw/audio, (continued)
- [PULL 11/35] vt82c686: Split off via-[am]c97 into separate file in hw/audio, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 12/35] audio/via-ac97: Simplify code and set user_creatable to false, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 13/35] vt82c686: Remove legacy vt82c686b_isa_init() function, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 14/35] vt82c686: Remove legacy vt82c686b_pm_init() function, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 15/35] vt82c686: Convert debug printf to trace points, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 17/35] vt82c686: Use shorter name for local variable holding object state, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 16/35] vt82c686: Remove unneeded includes and defines, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 18/35] vt82c686: Rename superio config related parts, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 19/35] clock: Introduce clock_ticks_to_ns(), Philippe Mathieu-Daudé, 2021/01/03
- [PULL 20/35] target/mips: Don't use clock_get_ns() in clock period calculation, Philippe Mathieu-Daudé, 2021/01/03
- [PULL 21/35] clock: Remove clock_get_ns(),
Philippe Mathieu-Daudé <=
- [PULL 22/35] clock: Define and use new clock_display_freq(), Philippe Mathieu-Daudé, 2021/01/03
- [PULL 24/35] hw/mips: Implement fw_cfg_arch_key_name(), Philippe Mathieu-Daudé, 2021/01/03
- [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Philippe Mathieu-Daudé, 2021/01/03
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Peter Maydell, 2021/01/10
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Philippe Mathieu-Daudé, 2021/01/10
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, BALATON Zoltan, 2021/01/10
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Huacai Chen, 2021/01/10
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Jiaxun Yang, 2021/01/10
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, BALATON Zoltan, 2021/01/11
- Re: [PULL 23/35] hw/intc: Rework Loongson LIOINTC, Peter Maydell, 2021/01/11