Tue, Apr 15, 2025 at 08:15:42PM +0200, [email protected] wrote:
>Add new callback ops for a dpll device.
>- features_get(..) - to obtain currently configured features from dpll
> device,
>- feature_set(..) - to allow dpll device features configuration.
>Provide features attribute and allow control over it to the users if
>device driver implements callbacks.
>
>Reviewed-by: Milena Olech <[email protected]>
>Signed-off-by: Arkadiusz Kubalewski <[email protected]>
>---
>v2:
>- adapt changes and align wiht new dpll_device_info struct
>---
> drivers/dpll/dpll_netlink.c | 79 ++++++++++++++++++++++++++++++++++++-
> include/linux/dpll.h | 5 +++
> 2 files changed, 82 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
>index 2de9ec08d551..acfdd87fcffe 100644
>--- a/drivers/dpll/dpll_netlink.c
>+++ b/drivers/dpll/dpll_netlink.c
>@@ -126,6 +126,25 @@ dpll_msg_add_mode_supported(struct sk_buff *msg, struct
>dpll_device *dpll,
> return 0;
> }
>
>+static int
>+dpll_msg_add_features(struct sk_buff *msg, struct dpll_device *dpll,
>+ struct netlink_ext_ack *extack)
>+{
>+ const struct dpll_device_ops *ops = dpll_device_ops(dpll);
>+ u32 features;
>+ int ret;
>+
>+ if (!ops->features_get)
>+ return 0;
>+ ret = ops->features_get(dpll, dpll_priv(dpll), &features, extack);
>+ if (ret)
>+ return ret;
>+ if (nla_put_u32(msg, DPLL_A_FEATURES, features))
>+ return -EMSGSIZE;
>+
>+ return 0;
>+}
>+
> static int
> dpll_msg_add_lock_status(struct sk_buff *msg, struct dpll_device *dpll,
> struct netlink_ext_ack *extack)
>@@ -592,6 +611,11 @@ dpll_device_get_one(struct dpll_device *dpll, struct
>sk_buff *msg,
> return ret;
> if (nla_put_u32(msg, DPLL_A_TYPE, info->type))
> return -EMSGSIZE;
>+ if (nla_put_u32(msg, DPLL_A_CAPABILITIES, info->capabilities))
>+ return -EMSGSIZE;
>+ ret = dpll_msg_add_features(msg, dpll, extack);
>+ if (ret)
>+ return ret;
>
> return 0;
> }
>@@ -747,6 +771,34 @@ int dpll_pin_change_ntf(struct dpll_pin *pin)
> }
> EXPORT_SYMBOL_GPL(dpll_pin_change_ntf);
>
>+static int
>+dpll_features_set(struct dpll_device *dpll, struct nlattr *a,
>+ struct netlink_ext_ack *extack)
>+{
>+ const struct dpll_device_info *info = dpll_device_info(dpll);
>+ const struct dpll_device_ops *ops = dpll_device_ops(dpll);
>+ u32 features = nla_get_u32(a), old_features;
>+ int ret;
>+
>+ if (features && !(info->capabilities & features)) {
>+ NL_SET_ERR_MSG_ATTR(extack, a, "dpll device not capable of this
>features");
>+ return -EOPNOTSUPP;
>+ }
>+ if (!ops->features_get || !ops->features_set) {
>+ NL_SET_ERR_MSG(extack, "dpll device not supporting any
>features");
>+ return -EOPNOTSUPP;
>+ }
>+ ret = ops->features_get(dpll, dpll_priv(dpll), &old_features, extack);
>+ if (ret) {
>+ NL_SET_ERR_MSG(extack, "unable to get old features value");
>+ return ret;
>+ }
>+ if (old_features == features)
>+ return -EINVAL;
>+
>+ return ops->features_set(dpll, dpll_priv(dpll), features, extack);
So you allow to enable/disable them all in once. What if user want to
enable feature A and does not care about feature B that may of may not
be previously set?
How many of the features do you expect to appear in the future. I'm
asking because this could be just a bool attr with a separate op to the
driver. If we have 3, no problem. Benefit is, you may also extend it
easily to pass some non-bool configuration. My point is, what is the
benefit of features bitset here?
>+}
>+
> static int
> dpll_pin_freq_set(struct dpll_pin *pin, struct nlattr *a,
> struct netlink_ext_ack *extack)
>@@ -1536,10 +1588,33 @@ int dpll_nl_device_get_doit(struct sk_buff *skb,
>struct genl_info *info)
> return genlmsg_reply(msg, info);
> }
>
>+static int
>+dpll_set_from_nlattr(struct dpll_device *dpll, struct genl_info *info)
>+{
>+ struct nlattr *a;
>+ int rem, ret;
>+
>+ nla_for_each_attr(a, genlmsg_data(info->genlhdr),
>+ genlmsg_len(info->genlhdr), rem) {
>+ switch (nla_type(a)) {
>+ case DPLL_A_FEATURES:
>+ ret = dpll_features_set(dpll, a, info->extack);
>+ if (ret)
>+ return ret;
>+ break;
>+ default:
>+ break;
>+ }
>+ }
>+
>+ return 0;
>+}
>+
> int dpll_nl_device_set_doit(struct sk_buff *skb, struct genl_info *info)
> {
>- /* placeholder for set command */
>- return 0;
>+ struct dpll_device *dpll = info->user_ptr[0];
>+
>+ return dpll_set_from_nlattr(dpll, info);
> }
>
> int dpll_nl_device_get_dumpit(struct sk_buff *skb, struct netlink_callback
> *cb)
>diff --git a/include/linux/dpll.h b/include/linux/dpll.h
>index 0489464af958..90c743daf64b 100644
>--- a/include/linux/dpll.h
>+++ b/include/linux/dpll.h
>@@ -30,6 +30,10 @@ struct dpll_device_ops {
> void *dpll_priv,
> unsigned long *qls,
> struct netlink_ext_ack *extack);
>+ int (*features_set)(const struct dpll_device *dpll, void *dpll_priv,
>+ u32 features, struct netlink_ext_ack *extack);
>+ int (*features_get)(const struct dpll_device *dpll, void *dpll_priv,
>+ u32 *features, struct netlink_ext_ack *extack);
> };
>
> struct dpll_pin_ops {
>@@ -99,6 +103,7 @@ struct dpll_pin_ops {
>
> struct dpll_device_info {
> enum dpll_type type;
>+ u32 capabilities;
> const struct dpll_device_ops *ops;
> };
>
>--
>2.38.1
>
