Re: [PATCH 2/2] hw: timer: ibex_timer: update/add reg address

[Alistair Francis <alistair23@gmail.com>]

On Mon, Jan 10, 2022 at 4:13 PM Alistair Francis
<alistair.francis@opensource.wdc.com> wrote:
>
> From: Wilfred Mallawa <wilfred.mallawa@wdc.com>
>
> The following changes:
> 1. Fixes the incorrectly set CTRL register address. As
> per [1] https://docs.opentitan.org/hw/ip/rv_timer/doc/#register-table
>
> The CTRL register is @ 0x04.
>
> This was found when attempting to fixup a bug where a timer_interrupt
> was not serviced on TockOS-OpenTitan.
>
> 2. Adds ALERT_TEST register as documented on [1], adding repective
>    switch cases to error handle and later implement functionality.
>
> Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/timer/ibex_timer.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/hw/timer/ibex_timer.c b/hw/timer/ibex_timer.c
> index 66e1f8e48c..096588ac8a 100644
> --- a/hw/timer/ibex_timer.c
> +++ b/hw/timer/ibex_timer.c
> @@ -34,7 +34,9 @@
>  #include "target/riscv/cpu.h"
>  #include "migration/vmstate.h"
>
> -REG32(CTRL, 0x00)
> +REG32(ALERT_TEST, 0x00)
> +    FIELD(ALERT_TEST, FATAL_FAULT, 0, 1)
> +REG32(CTRL, 0x04)
>      FIELD(CTRL, ACTIVE, 0, 1)
>  REG32(CFG0, 0x100)
>      FIELD(CFG0, PRESCALE, 0, 12)
> @@ -143,6 +145,10 @@ static uint64_t ibex_timer_read(void *opaque, hwaddr addr,
>      uint64_t retvalue = 0;
>
>      switch (addr >> 2) {
> +    case R_ALERT_TEST:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                        "Attempted to read ALERT_TEST, a write only register");
> +        break;
>      case R_CTRL:
>          retvalue = s->timer_ctrl;
>          break;
> @@ -186,6 +192,9 @@ static void ibex_timer_write(void *opaque, hwaddr addr,
>      uint32_t val = val64;
>
>      switch (addr >> 2) {
> +    case R_ALERT_TEST:
> +        qemu_log_mask(LOG_UNIMP, "Alert triggering not supported");
> +        break;
>      case R_CTRL:
>          s->timer_ctrl = val;
>          break;
> --
> 2.34.1
>