Currently, the DPLL subsystem assumes that the only supported mode is the one currently active on the device. When dpll_msg_add_mode_supported() is called, it relies on ops->mode_get() and reports that single mode to userspace. This prevents users from discovering other modes the device might be capable of. Add a new callback .supported_modes_get() to struct dpll_device_ops. This allows drivers to populate a bitmap indicating all modes supported by the hardware. Update dpll_msg_add_mode_supported() to utilize this new callback: * if ops->supported_modes_get is defined, use it to retrieve the full bitmap of supported modes. * if not defined, fall back to the existing behavior: retrieve the current mode via ops->mode_get and set the corresponding bit in the bitmap. Finally, iterate over the bitmap and add a DPLL_A_MODE_SUPPORTED netlink attribute for every set bit, accurately reporting the device's capabilities to userspace. Reviewed-by: Vadim Fedorenko Signed-off-by: Ivan Vecera --- drivers/dpll/dpll_netlink.c | 27 +++++++++++++++++++-------- include/linux/dpll.h | 3 +++ 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c index 64944f601ee5a..d6a0e272d7038 100644 --- a/drivers/dpll/dpll_netlink.c +++ b/drivers/dpll/dpll_netlink.c @@ -128,18 +128,29 @@ dpll_msg_add_mode_supported(struct sk_buff *msg, struct dpll_device *dpll, struct netlink_ext_ack *extack) { const struct dpll_device_ops *ops = dpll_device_ops(dpll); + DECLARE_BITMAP(modes, DPLL_MODE_MAX + 1) = { 0 }; enum dpll_mode mode; int ret; - /* No mode change is supported now, so the only supported mode is the - * one obtained by mode_get(). - */ + if (ops->supported_modes_get) { + ret = ops->supported_modes_get(dpll, dpll_priv(dpll), modes, + extack); + if (ret) + return ret; + } else { + /* If the supported modes are not reported by the driver, the + * only supported mode is the one obtained by mode_get(). + */ + ret = ops->mode_get(dpll, dpll_priv(dpll), &mode, extack); + if (ret) + return ret; - ret = ops->mode_get(dpll, dpll_priv(dpll), &mode, extack); - if (ret) - return ret; - if (nla_put_u32(msg, DPLL_A_MODE_SUPPORTED, mode)) - return -EMSGSIZE; + __set_bit(mode, modes); + } + + for_each_set_bit(mode, modes, DPLL_MODE_MAX + 1) + if (nla_put_u32(msg, DPLL_A_MODE_SUPPORTED, mode)) + return -EMSGSIZE; return 0; } diff --git a/include/linux/dpll.h b/include/linux/dpll.h index 562f520b23c27..912a2ca3e0ee7 100644 --- a/include/linux/dpll.h +++ b/include/linux/dpll.h @@ -20,6 +20,9 @@ struct dpll_pin_esync; struct dpll_device_ops { int (*mode_get)(const struct dpll_device *dpll, void *dpll_priv, enum dpll_mode *mode, struct netlink_ext_ack *extack); + int (*supported_modes_get)(const struct dpll_device *dpll, + void *dpll_priv, unsigned long *modes, + struct netlink_ext_ack *extack); int (*lock_status_get)(const struct dpll_device *dpll, void *dpll_priv, enum dpll_lock_status *status, enum dpll_lock_status_error *status_error, -- 2.52.0