Re: [PATCH v1 3/3] hw/riscv: OpenTitan: Connect the mtime and mtimecmp timer

[Alistair Francis]

On Tue, Jun 1, 2021 at 11:10 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> On Mon, May 31, 2021 at 12:33 PM Alistair Francis
> <alistair.francis@wdc.com> wrote:
> >
>
> Please write some commit message here

Done.

>
> > Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> > ---
> >  include/hw/riscv/opentitan.h |  5 ++++-
> >  hw/riscv/opentitan.c         | 14 +++++++++++---
> >  2 files changed, 15 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/hw/riscv/opentitan.h b/include/hw/riscv/opentitan.h
> > index aab9bc9245..86cceef698 100644
> > --- a/include/hw/riscv/opentitan.h
> > +++ b/include/hw/riscv/opentitan.h
> > @@ -22,6 +22,7 @@
> >  #include "hw/riscv/riscv_hart.h"
> >  #include "hw/intc/ibex_plic.h"
> >  #include "hw/char/ibex_uart.h"
> > +#include "hw/timer/ibex_timer.h"
> >  #include "qom/object.h"
> >
> >  #define TYPE_RISCV_IBEX_SOC "riscv.lowrisc.ibex.soc"
> > @@ -35,6 +36,7 @@ struct LowRISCIbexSoCState {
> >      RISCVHartArrayState cpus;
> >      IbexPlicState plic;
> >      IbexUartState uart;
> > +    IbexTimerState timer;
> >
> >      MemoryRegion flash_mem;
> >      MemoryRegion rom;
> > @@ -57,7 +59,7 @@ enum {
> >      IBEX_DEV_SPI,
> >      IBEX_DEV_I2C,
> >      IBEX_DEV_PATTGEN,
> > -    IBEX_DEV_RV_TIMER,
> > +    IBEX_DEV_TIMER,
> >      IBEX_DEV_SENSOR_CTRL,
> >      IBEX_DEV_OTP_CTRL,
> >      IBEX_DEV_PWRMGR,
> > @@ -82,6 +84,7 @@ enum {
> >  };
> >
> >  enum {
> > +    IBEX_TIMER_TIMEREXPIRED0_0 = 125,
>
> So this timer is connected to PLIC, instead of a dedicated exception
> code in the *cause CSR?

It is connected to both. It triggers the bit in MIE and can also
trigger an interrupt via the PLIC.

Alistair

>
> >      IBEX_UART0_RX_PARITY_ERR_IRQ = 8,
> >      IBEX_UART0_RX_TIMEOUT_IRQ = 7,
> >      IBEX_UART0_RX_BREAK_ERR_IRQ = 6,
> > diff --git a/hw/riscv/opentitan.c b/hw/riscv/opentitan.c
> > index 7545dcda9c..c5a7e3bacb 100644
> > --- a/hw/riscv/opentitan.c
> > +++ b/hw/riscv/opentitan.c
> > @@ -36,7 +36,7 @@ static const MemMapEntry ibex_memmap[] = {
> >      [IBEX_DEV_SPI] =            {  0x40050000,  0x1000  },
> >      [IBEX_DEV_I2C] =            {  0x40080000,  0x1000  },
> >      [IBEX_DEV_PATTGEN] =        {  0x400e0000,  0x1000  },
> > -    [IBEX_DEV_RV_TIMER] =       {  0x40100000,  0x1000  },
> > +    [IBEX_DEV_TIMER] =          {  0x40100000,  0x1000  },
> >      [IBEX_DEV_SENSOR_CTRL] =    {  0x40110000,  0x1000  },
> >      [IBEX_DEV_OTP_CTRL] =       {  0x40130000,  0x4000  },
> >      [IBEX_DEV_PWRMGR] =         {  0x40400000,  0x1000  },
> > @@ -106,6 +106,8 @@ static void lowrisc_ibex_soc_init(Object *obj)
> >      object_initialize_child(obj, "plic", &s->plic, TYPE_IBEX_PLIC);
> >
> >      object_initialize_child(obj, "uart", &s->uart, TYPE_IBEX_UART);
> > +
> > +    object_initialize_child(obj, "timer", &s->timer, TYPE_IBEX_TIMER);
> >  }
> >
> >  static void lowrisc_ibex_soc_realize(DeviceState *dev_soc, Error **errp)
> > @@ -159,6 +161,14 @@ static void lowrisc_ibex_soc_realize(DeviceState 
> > *dev_soc, Error **errp)
> >                         3, qdev_get_gpio_in(DEVICE(&s->plic),
> >                         IBEX_UART0_RX_OVERFLOW_IRQ));
> >
> > +    if (!sysbus_realize(SYS_BUS_DEVICE(&s->timer), errp)) {
> > +        return;
> > +    }
> > +    sysbus_mmio_map(SYS_BUS_DEVICE(&s->timer), 0, 
> > memmap[IBEX_DEV_TIMER].base);
> > +    sysbus_connect_irq(SYS_BUS_DEVICE(&s->timer),
> > +                       0, qdev_get_gpio_in(DEVICE(&s->plic),
> > +                       IBEX_TIMER_TIMEREXPIRED0_0));
> > +
> >      create_unimplemented_device("riscv.lowrisc.ibex.gpio",
> >          memmap[IBEX_DEV_GPIO].base, memmap[IBEX_DEV_GPIO].size);
> >      create_unimplemented_device("riscv.lowrisc.ibex.spi",
> > @@ -167,8 +177,6 @@ static void lowrisc_ibex_soc_realize(DeviceState 
> > *dev_soc, Error **errp)
> >          memmap[IBEX_DEV_I2C].base, memmap[IBEX_DEV_I2C].size);
> >      create_unimplemented_device("riscv.lowrisc.ibex.pattgen",
> >          memmap[IBEX_DEV_PATTGEN].base, memmap[IBEX_DEV_PATTGEN].size);
> > -    create_unimplemented_device("riscv.lowrisc.ibex.rv_timer",
> > -        memmap[IBEX_DEV_RV_TIMER].base, memmap[IBEX_DEV_RV_TIMER].size);
> >      create_unimplemented_device("riscv.lowrisc.ibex.sensor_ctrl",
> >          memmap[IBEX_DEV_SENSOR_CTRL].base, 
> > memmap[IBEX_DEV_SENSOR_CTRL].size);
> >      create_unimplemented_device("riscv.lowrisc.ibex.otp_ctrl",
>
> Regards,
> Bin