diff options
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/arm_ffa/driver.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index c9fb56afbcb4..6e0c883ab708 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -167,6 +167,28 @@ struct ffa_drv_info { static struct ffa_drv_info *drv_info; +/* + * The driver must be able to support all the versions from the earliest + * supported FFA_MIN_VERSION to the latest supported FFA_DRIVER_VERSION. + * The specification states that if firmware supports a FFA implementation + * that is incompatible with and at a greater version number than specified + * by the caller(FFA_DRIVER_VERSION passed as parameter to FFA_VERSION), + * it must return the NOT_SUPPORTED error code. + */ +static u32 ffa_compatible_version_find(u32 version) +{ + u32 compat_version; + u16 major = MAJOR_VERSION(version), minor = MINOR_VERSION(version); + u16 drv_major = MAJOR_VERSION(FFA_DRIVER_VERSION); + u16 drv_minor = MINOR_VERSION(FFA_DRIVER_VERSION); + + if ((major < drv_major) || (major == drv_major && minor <= drv_minor)) + return version; + + pr_info("Firmware version higher than driver version, downgrading\n"); + return FFA_DRIVER_VERSION; +} + static int ffa_version_check(u32 *version) { ffa_value_t ver; @@ -180,15 +202,20 @@ static int ffa_version_check(u32 *version) return -EOPNOTSUPP; } - if (ver.a0 < FFA_MIN_VERSION || ver.a0 > FFA_DRIVER_VERSION) { - pr_err("Incompatible version %d.%d found\n", - MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0)); + if (ver.a0 < FFA_MIN_VERSION) { + pr_err("Incompatible v%d.%d! Earliest supported v%d.%d\n", + MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0), + MAJOR_VERSION(FFA_MIN_VERSION), + MINOR_VERSION(FFA_MIN_VERSION)); return -EINVAL; } - *version = ver.a0; - pr_info("Version %d.%d found\n", MAJOR_VERSION(ver.a0), + pr_info("Driver version %d.%d\n", MAJOR_VERSION(FFA_DRIVER_VERSION), + MINOR_VERSION(FFA_DRIVER_VERSION)); + pr_info("Firmware version %d.%d found\n", MAJOR_VERSION(ver.a0), MINOR_VERSION(ver.a0)); + *version = ffa_compatible_version_find(ver.a0); + return 0; } |