| Message ID | 20240322155810.5733-2-philmd@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hw/clock: Propagate clock changes when STM32L4X5 MUX is updated | expand |
On Fri, 22 Mar 2024 at 15:58, Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > Let clock_set_mul_div() return a boolean value whether the > clock has been updated or not, similarly to clock_set(). > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > include/hw/clock.h | 4 +++- > hw/core/clock.c | 8 +++++++- > 2 files changed, 10 insertions(+), 2 deletions(-) I guess this makes sense, especially since you often would like to know this to decide whether to call clock_propagate(). We should also update the docs/devel/clocks.rst to mention this. thanks -- PMM
On 16:58 Fri 22 Mar , Philippe Mathieu-Daudé wrote: > Let clock_set_mul_div() return a boolean value whether the > clock has been updated or not, similarly to clock_set(). > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Acked-by: Luc Michel <luc@lmichel.fr> > --- > include/hw/clock.h | 4 +++- > hw/core/clock.c | 8 +++++++- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/include/hw/clock.h b/include/hw/clock.h > index bb12117f67..eb58599131 100644 > --- a/include/hw/clock.h > +++ b/include/hw/clock.h > @@ -357,6 +357,8 @@ char *clock_display_freq(Clock *clk); > * @multiplier: multiplier value > * @divider: divider value > * > + * @return: true if the clock is changed. > + * > * By default, a Clock's children will all run with the same period > * as their parent. This function allows you to adjust the multiplier > * and divider used to derive the child clock frequency. > @@ -374,6 +376,6 @@ char *clock_display_freq(Clock *clk); > * Note that this function does not call clock_propagate(); the > * caller should do that if necessary. > */ > -void clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider); > +bool clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider); > > #endif /* QEMU_HW_CLOCK_H */ > diff --git a/hw/core/clock.c b/hw/core/clock.c > index d82e44cd1a..a19c7db7df 100644 > --- a/hw/core/clock.c > +++ b/hw/core/clock.c > @@ -143,14 +143,20 @@ char *clock_display_freq(Clock *clk) > return freq_to_str(clock_get_hz(clk)); > } > > -void clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider) > +bool clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider) > { > assert(divider != 0); > > + if (clk->multiplier == multiplier && clk->divider == divider) { > + return false; > + } > + > trace_clock_set_mul_div(CLOCK_PATH(clk), clk->multiplier, multiplier, > clk->divider, divider); > clk->multiplier = multiplier; > clk->divider = divider; > + > + return true; > } > > static void clock_initfn(Object *obj) > -- > 2.41.0 >
On 09:40 Mon 25 Mar , Luc Michel wrote: > On 16:58 Fri 22 Mar , Philippe Mathieu-Daudé wrote: > > Let clock_set_mul_div() return a boolean value whether the > > clock has been updated or not, similarly to clock_set(). > > > > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > > Acked-by: Luc Michel <luc@lmichel.fr> Sorry, I forgot, as Peter suggested, can you add a word in the doc about this? Something in the vein of: + Similary to ``clock_set()``, ``clock_set_mul_div()`` returns ``true`` if + the clock state was modified, that it, if the multiplier or the diviser + or both were changed by the call. + Note that ``clock_set_mul_div()`` does not automatically call ``clock_propagate()``. If you make a runtime change to the multiplier or divider you must call clock_propagate() yourself. Thanks!
diff --git a/include/hw/clock.h b/include/hw/clock.h index bb12117f67..eb58599131 100644 --- a/include/hw/clock.h +++ b/include/hw/clock.h @@ -357,6 +357,8 @@ char *clock_display_freq(Clock *clk); * @multiplier: multiplier value * @divider: divider value * + * @return: true if the clock is changed. + * * By default, a Clock's children will all run with the same period * as their parent. This function allows you to adjust the multiplier * and divider used to derive the child clock frequency. @@ -374,6 +376,6 @@ char *clock_display_freq(Clock *clk); * Note that this function does not call clock_propagate(); the * caller should do that if necessary. */ -void clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider); +bool clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider); #endif /* QEMU_HW_CLOCK_H */ diff --git a/hw/core/clock.c b/hw/core/clock.c index d82e44cd1a..a19c7db7df 100644 --- a/hw/core/clock.c +++ b/hw/core/clock.c @@ -143,14 +143,20 @@ char *clock_display_freq(Clock *clk) return freq_to_str(clock_get_hz(clk)); } -void clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider) +bool clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider) { assert(divider != 0); + if (clk->multiplier == multiplier && clk->divider == divider) { + return false; + } + trace_clock_set_mul_div(CLOCK_PATH(clk), clk->multiplier, multiplier, clk->divider, divider); clk->multiplier = multiplier; clk->divider = divider; + + return true; } static void clock_initfn(Object *obj)
Let clock_set_mul_div() return a boolean value whether the clock has been updated or not, similarly to clock_set(). Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- include/hw/clock.h | 4 +++- hw/core/clock.c | 8 +++++++- 2 files changed, 10 insertions(+), 2 deletions(-)