[PATCH net-next v1 3/4] dpll: features_get/set callbacks

[Arkadiusz Kubalewski]

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 <milena.olech@xxxxxxxxx>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@xxxxxxxxx>
---
 drivers/dpll/dpll_netlink.c | 76 ++++++++++++++++++++++++++++++++++++-
 include/linux/dpll.h        |  4 ++
 2 files changed, 78 insertions(+), 2 deletions(-)

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 41aed0d29be2..41eb848ce021 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)
@@ -593,6 +612,9 @@ dpll_device_get_one(struct dpll_device *dpll, struct sk_buff *msg,
 		return -EMSGSIZE;
 	if (nla_put_u32(msg, DPLL_A_CAPABILITIES, dpll->capabilities))
 		return -EMSGSIZE;
+	ret = dpll_msg_add_features(msg, dpll, extack);
+	if (ret)
+		return ret;
 
 	return 0;
 }
@@ -748,6 +770,33 @@ 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_ops *ops = dpll_device_ops(dpll);
+	u32 features = nla_get_u32(a), old_features;
+	int ret;
+
+	if (features && !(dpll->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);
+}
+
 static int
 dpll_pin_freq_set(struct dpll_pin *pin, struct nlattr *a,
 		  struct netlink_ext_ack *extack)
@@ -1535,10 +1584,33 @@ 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 dde8dee83dc6..5432d8479ed5 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 {
-- 
2.38.1