This is a follow-up commit for the sysfs attributes to change
from DRIVER_ATTR to DEVICE_ATTR according to some initial comments.
In such case, it's better to point the sysfs path to the device
itself instead of the driver. The ABI document is also updated.
Fixes: 79e29cb8fb ("platform/mellanox: Add bootctl driver for Mellanox BlueField Soc")
Signed-off-by: Liming Sun <lsun@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit adds the bootctl platform driver for Mellanox BlueField
Soc, which queries secure state and controls the eMMC boot partition
swapping by sending SMC calls to ATF running at EL3.
Below are the sequences of typical use case.
1. User requests boot partition swapping, which could be on-demand or
during boot-image upgrade via UEFI capsule;
2. This bootctl driver handles the request and sends SMC call
to ATF. ATF programs register BREADCRUMB0 which has value
preserved during warm reset. It also programs eMMC to swap
the boot partition;
3. After software reset (rebooting), ATF BL1 (BootRom) checks
register BREADCRUMB0 and enable watchdog if configured;
4. If booting fails, the watchdog timer will trigger rebooting.
In such case, ATF Boot ROM will switch the boot partition
back to the previous one. This is a robust feature and used
to prevent failure during boot partition upgrade.
Reviewed-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Liming Sun <lsun@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
