[PATCH 3/4] lib: sbi: Add SBI watchdog framework

[Rahul Pathak]

On Fri, Oct 2, 2026 at 2:01 PM Prajwal N <prajwal.n at oss.qualcomm.com> wrote:
>
> Update the build infrastructure to include the SBI
> watchdog compilation.
>
> Implement the SBI watchdog functionality including
> start, stop, pat, read and write attributes,
> pretimeout and timeout handlers.
>
> Signed-off-by: Prajwal N <prajwal.n at oss.qualcomm.com>
> ---
>  include/sbi/sbi_wdt.h |  72 +++++++
>  lib/sbi/objects.mk    |   1 +
>  lib/sbi/sbi_init.c    |   8 +
>  lib/sbi/sbi_wdt.c     | 455 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 536 insertions(+)
>  create mode 100644 include/sbi/sbi_wdt.h
>  create mode 100644 lib/sbi/sbi_wdt.c
>
> +
> +int sbi_watchdog_write_attribute(u32 attribute_id, u32 attribute_value)
> +{
> +       int ret;
> +
> +       spin_lock(&sbi_system_watchdog->wdt_lock);
> +
> +       /* Check if the attribute is writable */
> +       if (!(sbi_watchdog_attr_perm[attribute_id] & WDT_ATTR_PERM_W)) {

attribute_id must be validated here before it's used for any access.

> +               ret = SBI_ERR_DENIED;
> +               goto out;
> +       }
> +
> +       switch (attribute_id) {
> +       case SBI_WDT_PERIOD:
> +               /* Return error if wdt_period passed is less than wdt_min_period */
> +               if (attribute_value < sbi_system_watchdog->wdt_attr.wdt_min_period) {
> +                       ret = SBI_ERR_FAILED;
> +                       goto out;
> +               }
> +               break;
> +
> +       case SBI_WDT_NOTIF_TIME:
> +               /* Ignore the write if the MSI capability is not enabled */
> +               if (!CAP_GET(sbi_system_watchdog->wdt_attr.wdt_capability, WDT_CAP_MSI_MASK)) {
> +                       ret = SBI_SUCCESS;
> +                       goto out;
> +               }
> +
> +               /* Returen error if the notif time is greater than the timeout period*/
> +               if (attribute_value >= sbi_system_watchdog->wdt_attr.wdt_period) {
> +                       ret = SBI_ERR_FAILED;
> +                       goto out;
> +               }
> +               break;
> +
> +       case SBI_WDT_NOTIF_MSI_ADDR_LOW:
> +       case SBI_WDT_NOTIF_MSI_ADDR_HIGH:
> +       case SBI_WDT_NOTIF_MSI_DATA:
> +               /* Ignore the write if the MSI capability is not enabled */
> +               if (!CAP_GET(sbi_system_watchdog->wdt_attr.wdt_capability, WDT_CAP_MSI_MASK)) {
> +                       ret = SBI_SUCCESS;
> +                       goto out;
> +               }
> +
> +               /*
> +                * The MSI address and data can be written only when
> +                * the notifications are disabled
> +                */
> +               if (sbi_system_watchdog->wdt_attr.wdt_notif_time != 0) {
> +                       ret = SBI_ERR_FAILED;
> +                       goto out;
> +               }
> +               break;
> +
> +       default:
> +               /* Return error if the attribute index is out of bound*/
> +               if (attribute_id >= SBI_WDT_ATTR_MAX) {
> +                       ret = SBI_ERR_INVALID_PARAM;
> +                       goto out;
> +               }
> +               break;
> +       }
> +
> +       u32 *wdt_attrs = (u32 *)&sbi_system_watchdog->wdt_attr;
> +       wdt_attrs[attribute_id] = attribute_value;
> +
> +       ret = SBI_SUCCESS;
> +
> +out:
> +       spin_unlock(&sbi_system_watchdog->wdt_lock);
> +       return ret;
> +}
> +