Re: [SPAM] [PATCH v5 07/10] hw/misc/aspeed_sbc: Add CAMP2 support for OTP data reads

["Cédric Le Goater" <clg@kaod.org>]

On 8/12/25 11:40, Kane Chen wrote:
> From: Kane-Chen-AS <kane_chen@aspeedtech.com>
> 
> The OTP space contains three types of entries: data, conf, and strap.
> Data entries consist of two DWORDs, while the other types contain
> only one DWORD. This change adds the R_CAMP2 register (0x024 / 4) to
> store the second DWORD when reading from the OTP data region.
> 
> With this enhancement, OTP reads now correctly return both DWORDs for
> data entries via the CAMP registers, along with improved address
> validation and error handling.
> 
> Signed-off-by: Kane-Chen-AS <kane_chen@aspeedtech.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/misc/aspeed_sbc.c | 27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
> 
> diff --git a/hw/misc/aspeed_sbc.c b/hw/misc/aspeed_sbc.c
> index 052c70fd42..787e2d0489 100644
> --- a/hw/misc/aspeed_sbc.c
> +++ b/hw/misc/aspeed_sbc.c
> @@ -22,6 +22,7 @@
>   #define R_ADDR          (0x010 / 4)
>   #define R_STATUS        (0x014 / 4)
>   #define R_CAMP1         (0x020 / 4)
> +#define R_CAMP2         (0x024 / 4)
>   #define R_QSR           (0x040 / 4)
>   
>   /* R_STATUS */
> @@ -50,6 +51,8 @@
>   #define SBC_OTP_CMD_READ 0x23b1e361
>   #define SBC_OTP_CMD_PROG 0x23b1e364
>   
> +#define OTP_DATA_DWORD_COUNT        (0x800)
> +#define OTP_TOTAL_DWORD_COUNT       (0x1000)
>   static uint64_t aspeed_sbc_read(void *opaque, hwaddr addr, unsigned int size)
>   {
>       AspeedSBCState *s = ASPEED_SBC(opaque);
> @@ -72,6 +75,16 @@ static bool aspeed_sbc_otp_read(AspeedSBCState *s,
>       MemTxResult ret;
>       AspeedOTPState *otp = &s->otp;
>       uint32_t value, otp_offset;
> +    bool is_data = false;
> +
> +    if (otp_addr < OTP_DATA_DWORD_COUNT) {
> +        is_data = true;
> +    } else if (otp_addr >= OTP_TOTAL_DWORD_COUNT) {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "Invalid OTP addr 0x%x\n",
> +                      otp_addr);
> +        return false;
> +    }
>   
>       otp_offset = otp_addr << 2;
>       ret = address_space_read(&otp->as, otp_offset, MEMTXATTRS_UNSPECIFIED,
> @@ -85,6 +98,20 @@ static bool aspeed_sbc_otp_read(AspeedSBCState *s,
>       s->regs[R_CAMP1] = value;
>       trace_aspeed_sbc_otp_read(otp_addr, value);
>   
> +    if (is_data) {
> +        ret = address_space_read(&otp->as, otp_offset + 4,
> +                                 MEMTXATTRS_UNSPECIFIED,
> +                                 &value, sizeof(value));
> +        if (ret != MEMTX_OK) {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "Failed to read OTP memory, addr = %x\n",
> +                          otp_addr);
> +            return false;
> +        }
> +        s->regs[R_CAMP2] = value;
> +        trace_aspeed_sbc_otp_read(otp_addr + 1, value);
> +    }
> +
>       return true;
>   }
>