On Mon, 12 Oct 2020 10:34:48 +0200 Philippe Mathieu-Daudé <f4...@amsat.org> wrote:
> Hi Huacai, > > On 10/11/20 5:52 AM, chen huacai wrote: > > Hi, Philippe, > > > > On Sun, Oct 11, 2020 at 4:43 AM Philippe Mathieu-Daudé <f4...@amsat.org> > > wrote: > >> > >> Since its introduction in commit 6af0bf9c7c3, > >> the 'r4k' machine runs at 200 MHz. > >> > >> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> > >> --- > >> hw/mips/r4k.c | 8 +++++++- > >> 1 file changed, 7 insertions(+), 1 deletion(-) > >> > >> diff --git a/hw/mips/r4k.c b/hw/mips/r4k.c > >> index 3487013a4a1..e64687b505a 100644 > >> --- a/hw/mips/r4k.c > >> +++ b/hw/mips/r4k.c > >> @@ -37,6 +37,7 @@ > >> #include "sysemu/reset.h" > >> #include "sysemu/runstate.h" > >> #include "qemu/error-report.h" > >> +#include "hw/qdev-clock.h" > >> > >> #define MAX_IDE_BUS 2 > >> > >> @@ -184,6 +185,7 @@ void mips_r4k_init(MachineState *machine) > >> int bios_size; > >> MIPSCPU *cpu; > >> CPUMIPSState *env; > >> + Clock *cpuclk; > >> ResetData *reset_info; > >> int i; > >> qemu_irq *i8259; > >> @@ -193,7 +195,11 @@ void mips_r4k_init(MachineState *machine) > >> int be; > >> > >> /* init CPUs */ > >> - cpu = MIPS_CPU(cpu_create(machine->cpu_type)); > >> + cpu = MIPS_CPU(object_new(machine->cpu_type)); > >> + cpuclk = clock_new(OBJECT(machine), "cpu-refclk"); > >> + clock_set_hz(cpuclk, 200000000); /* 200 MHz */ > >> + qdev_connect_clock_in(DEVICE(cpu), "clk-in", cpuclk); > >> + qdev_realize(DEVICE(cpu), NULL, &error_abort); > > > > Can we add a new parameter to cpu_create() and set the freq in the core > > code? > > Adding a new parameter seems a good idea. > > Both maintainers of the core code are reluctant to add > a CPU clock to the core code, see: > https://www.mail-archive.com/qemu-devel@nongnu.org/msg747589.html > https://www.mail-archive.com/qemu-devel@nongnu.org/msg747612.html > Which is why I restricted that to the MIPS CPUs. > the reason for that is that it's used only by a handful of devices and not widespread. > On ARM, Damien started to use clocks on the Zynq SoC (merged): > https://www.mail-archive.com/qemu-devel@nongnu.org/msg694604.html > Luc is working on adding a clock manager to the Broadcom SoC: > https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg02840.html > > I also started converting one UART devices: > https://www.mail-archive.com/qemu-devel@nongnu.org/msg727972.html > > So IMO the core code will soon require this. Maybe we will add it > during the next development window. > > Meanwhile I can add a mips_cpu_create_with_clock() in preparation boards that need property settings in between object_new() and realize() typically open code just that and/or use plug/preplug handler(callback) to set properties. preplug handler should work with cpu_create() just fine. If you have multiple mips boards that will new clock mechanism, mips_cpu_create_with_clock() wrapper would work as well (it's a bit less complicated compared to preplug handler but not too much) > of cpu_create_with_clock(). > > > > > Huacai > >> env = &cpu->env; > >> > >> reset_info = g_malloc0(sizeof(ResetData)); > >> -- > >> 2.26.2 > >> > > > > >
