[PATCH v3 net-next 1/4] net/ethtool: add netlink interface for the PLCA RS

[PATCH v3 net-next 1/4] net/ethtool: add netlink interface for the PLCA RS

[Piergiorgio Beruto]

Add support for configuring the PLCA Reconciliation Sublayer on
multi-drop PHYs that support IEEE802.3cg-2019 Clause 148 (e.g.,
10BASE-T1S). This patch adds the appropriate netlink interface
to ethtool.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
 MAINTAINERS                          |   6 +
 drivers/net/phy/phy.c                |  34 ++++
 drivers/net/phy/phy_device.c         |   3 +
 include/linux/ethtool.h              |  11 +
 include/linux/phy.h                  |  64 ++++++
 include/uapi/linux/ethtool_netlink.h |  25 +++
 net/ethtool/Makefile                 |   2 +-
 net/ethtool/netlink.c                |  30 +++
 net/ethtool/netlink.h                |   6 +
 net/ethtool/plca.c                   | 290 +++++++++++++++++++++++++++
 10 files changed, 470 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/plca.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 955c1be1efb2..7952243e4b43 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16396,6 +16396,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.yaml
 F:	drivers/iio/chemical/pms7003.c
 
+PLCA RECONCILIATION SUBLAYER (IEEE802.3 Clause 148)
+M:	Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
+L:	netdev@vger.kernel.org
+S:	Maintained
+F:	net/ethtool/plca.c
+
 PLDMFW LIBRARY
 M:	Jacob Keller <jacob.e.keller@intel.com>
 S:	Maintained
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e5b6cb1a77f9..99e3497b6aa1 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -543,6 +543,40 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
 }
 EXPORT_SYMBOL(phy_ethtool_get_stats);
 
+/**
+ *
+ */
+int phy_ethtool_get_plca_cfg(struct phy_device *dev,
+			     struct phy_plca_cfg *plca_cfg)
+{
+	// TODO
+	return 0;
+}
+EXPORT_SYMBOL(phy_ethtool_get_plca_cfg);
+
+/**
+ *
+ */
+int phy_ethtool_set_plca_cfg(struct phy_device *dev,
+			     struct netlink_ext_ack *extack,
+			     const struct phy_plca_cfg *plca_cfg)
+{
+	// TODO
+	return 0;
+}
+EXPORT_SYMBOL(phy_ethtool_set_plca_cfg);
+
+/**
+ *
+ */
+int phy_ethtool_get_plca_status(struct phy_device *dev,
+				struct phy_plca_status *plca_st)
+{
+	// TODO
+	return 0;
+}
+EXPORT_SYMBOL(phy_ethtool_get_plca_status);
+
 /**
  * phy_start_cable_test - Start a cable test
  *
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 716870a4499c..f248010c403d 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3262,6 +3262,9 @@ static const struct ethtool_phy_ops phy_ethtool_phy_ops = {
 	.get_sset_count		= phy_ethtool_get_sset_count,
 	.get_strings		= phy_ethtool_get_strings,
 	.get_stats		= phy_ethtool_get_stats,
+	.get_plca_cfg		= phy_ethtool_get_plca_cfg,
+	.set_plca_cfg		= phy_ethtool_set_plca_cfg,
+	.get_plca_status	= phy_ethtool_get_plca_status,
 	.start_cable_test	= phy_start_cable_test,
 	.start_cable_test_tdr	= phy_start_cable_test_tdr,
 };
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 9e0a76fc7de9..4bfe95ec1f0a 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -802,12 +802,16 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
 
 struct phy_device;
 struct phy_tdr_config;
+struct phy_plca_cfg;
+struct phy_plca_status;
 
 /**
  * struct ethtool_phy_ops - Optional PHY device options
  * @get_sset_count: Get number of strings that @get_strings will write.
  * @get_strings: Return a set of strings that describe the requested objects
  * @get_stats: Return extended statistics about the PHY device.
+ * @get_plca_cfg: Return PLCA configuration.
+ * @set_plca_cfg: Set PLCA configuration.
  * @start_cable_test: Start a cable test
  * @start_cable_test_tdr: Start a Time Domain Reflectometry cable test
  *
@@ -819,6 +823,13 @@ struct ethtool_phy_ops {
 	int (*get_strings)(struct phy_device *dev, u8 *data);
 	int (*get_stats)(struct phy_device *dev,
 			 struct ethtool_stats *stats, u64 *data);
+	int (*get_plca_cfg)(struct phy_device *dev,
+			    struct phy_plca_cfg *plca_cfg);
+	int (*set_plca_cfg)(struct phy_device *dev,
+			    struct netlink_ext_ack *extack,
+			    const struct phy_plca_cfg *plca_cfg);
+	int (*get_plca_status)(struct phy_device *dev,
+			       struct phy_plca_status *plca_st);
 	int (*start_cable_test)(struct phy_device *phydev,
 				struct netlink_ext_ack *extack);
 	int (*start_cable_test_tdr)(struct phy_device *phydev,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 71eeb4e3b1fd..ab2c134d0a05 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -765,6 +765,63 @@ struct phy_tdr_config {
 };
 #define PHY_PAIR_ALL -1
 
+/**
+ * struct phy_plca_cfg - Configuration of the PLCA (Physical Layer Collision
+ * Avoidance) Reconciliation Sublayer.
+ *
+ * @version: read-only PLCA register map version. 0 = not available. Ignored
+ *   when setting the configuration. Format is the same as reported by the PLCA
+ *   IDVER register (31.CA00). -1 = not available.
+ * @enabled: PLCA configured mode (enabled/disabled). -1 = not available / don't
+ *   set. 0 = disabled, anything else = enabled.
+ * @node_id: the PLCA local node identifier. -1 = not available / don't set.
+ *   Allowed values [0 .. 254]. 255 = node disabled.
+ * @node_cnt: the PLCA node count (maximum number of nodes having a TO). Only
+ *   meaningful for the coordinator (node_id = 0). -1 = not available / don't
+ *   set. Allowed values [0 .. 255].
+ * @to_tmr: The value of the PLCA to_timer in bit-times, which determines the
+ *   PLCA transmit opportunity window opening. See IEEE802.3 Clause 148 for
+ *   more details. The to_timer shall be set equal over all nodes.
+ *   -1 = not available / don't set. Allowed values [0 .. 255].
+ * @burst_cnt: controls how many additional frames a node is allowed to send in
+ *   single transmit opportunity (TO). The default value of 0 means that the
+ *   node is allowed exactly one frame per TO. A value of 1 allows two frames
+ *   per TO, and so on. -1 = not available / don't set.
+ *   Allowed values [0 .. 255].
+ * @burst_tmr: controls how many bit times to wait for the MAC to send a new
+ *   frame before interrupting the burst. This value should be set to a value
+ *   greater than the MAC inter-packet gap (which is typically 96 bits).
+ *   -1 = not available / don't set. Allowed values [0 .. 255].
+ *
+ * A structure containing configuration parameters for setting/getting the PLCA
+ * RS configuration. The driver does not need to implement all the parameters,
+ * but should report what is actually used.
+ */
+struct phy_plca_cfg {
+	s32 version;
+	s16 enabled;
+	s16 node_id;
+	s16 node_cnt;
+	s16 to_tmr;
+	s16 burst_cnt;
+	s16 burst_tmr;
+};
+
+/**
+ * struct phy_plca_status - Status of the PLCA (Physical Layer Collision
+ * Avoidance) Reconciliation Sublayer.
+ *
+ * @pst: The PLCA status as reported by the PST bit in the PLCA STATUS
+ *	register(31.CA03), indicating BEACON activity.
+ *
+ * A structure containing status information of the PLCA RS configuration.
+ * The driver does not need to implement all the parameters, but should report
+ * what is actually used.
+ */
+struct phy_plca_status {
+	bool pst;
+};
+
 /**
  * struct phy_driver - Driver structure for a particular PHY type
  *
@@ -1775,6 +1832,13 @@ int phy_ethtool_get_strings(struct phy_device *phydev, u8 *data);
 int phy_ethtool_get_sset_count(struct phy_device *phydev);
 int phy_ethtool_get_stats(struct phy_device *phydev,
 			  struct ethtool_stats *stats, u64 *data);
+int phy_ethtool_get_plca_cfg(struct phy_device *dev,
+			     struct phy_plca_cfg *plca_cfg);
+int phy_ethtool_set_plca_cfg(struct phy_device *dev,
+			     struct netlink_ext_ack *extack,
+			     const struct phy_plca_cfg *plca_cfg);
+int phy_ethtool_get_plca_status(struct phy_device *dev,
+				struct phy_plca_status *plca_st);
 
 static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
 {
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index aaf7c6963d61..81e3d7b42d0f 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -51,6 +51,9 @@ enum {
 	ETHTOOL_MSG_MODULE_SET,
 	ETHTOOL_MSG_PSE_GET,
 	ETHTOOL_MSG_PSE_SET,
+	ETHTOOL_MSG_PLCA_GET_CFG,
+	ETHTOOL_MSG_PLCA_SET_CFG,
+	ETHTOOL_MSG_PLCA_GET_STATUS,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -97,6 +100,9 @@ enum {
 	ETHTOOL_MSG_MODULE_GET_REPLY,
 	ETHTOOL_MSG_MODULE_NTF,
 	ETHTOOL_MSG_PSE_GET_REPLY,
+	ETHTOOL_MSG_PLCA_GET_CFG_REPLY,
+	ETHTOOL_MSG_PLCA_GET_STATUS_REPLY,
+	ETHTOOL_MSG_PLCA_NTF,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
@@ -880,6 +886,25 @@ enum {
 	ETHTOOL_A_PSE_MAX = (__ETHTOOL_A_PSE_CNT - 1)
 };
 
+/* PLCA */
+
+enum {
+	ETHTOOL_A_PLCA_UNSPEC,
+	ETHTOOL_A_PLCA_HEADER,				/* nest - _A_HEADER_* */
+	ETHTOOL_A_PLCA_VERSION,				/* u16 */
+	ETHTOOL_A_PLCA_ENABLED,				/* u8 */
+	ETHTOOL_A_PLCA_STATUS,				/* u8 */
+	ETHTOOL_A_PLCA_NODE_CNT,			/* u8 */
+	ETHTOOL_A_PLCA_NODE_ID,				/* u8 */
+	ETHTOOL_A_PLCA_TO_TMR,				/* u8 */
+	ETHTOOL_A_PLCA_BURST_CNT,			/* u8 */
+	ETHTOOL_A_PLCA_BURST_TMR,			/* u8 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_PLCA_CNT,
+	ETHTOOL_A_PLCA_MAX = (__ETHTOOL_A_PLCA_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 72ab0944262a..b18930e2ce9a 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -8,4 +8,4 @@ ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
 		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
 		   tunnels.o fec.o eeprom.o stats.o phc_vclocks.o module.o \
-		   pse-pd.o
+		   pse-pd.o plca.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 1a4c11356c96..eb044f48cb24 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -287,6 +287,8 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_PHC_VCLOCKS_GET]	= &ethnl_phc_vclocks_request_ops,
 	[ETHTOOL_MSG_MODULE_GET]	= &ethnl_module_request_ops,
 	[ETHTOOL_MSG_PSE_GET]		= &ethnl_pse_request_ops,
+	[ETHTOOL_MSG_PLCA_GET_CFG]	= &ethnl_plca_cfg_request_ops,
+	[ETHTOOL_MSG_PLCA_GET_STATUS]	= &ethnl_plca_status_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -602,6 +604,7 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
 	[ETHTOOL_MSG_EEE_NTF]		= &ethnl_eee_request_ops,
 	[ETHTOOL_MSG_FEC_NTF]		= &ethnl_fec_request_ops,
 	[ETHTOOL_MSG_MODULE_NTF]	= &ethnl_module_request_ops,
+	[ETHTOOL_MSG_PLCA_NTF]		= &ethnl_plca_cfg_request_ops,
 };
 
 /* default notification handler */
@@ -695,6 +698,7 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
 	[ETHTOOL_MSG_EEE_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_FEC_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_MODULE_NTF]	= ethnl_default_notify,
+	[ETHTOOL_MSG_PLCA_NTF]		= ethnl_default_notify,
 };
 
 void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
@@ -1040,6 +1044,32 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_pse_set_policy,
 		.maxattr = ARRAY_SIZE(ethnl_pse_set_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PLCA_GET_CFG,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+		.policy = ethnl_plca_get_cfg_policy,
+		.maxattr = ARRAY_SIZE(ethnl_plca_get_cfg_policy) - 1,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_PLCA_SET_CFG,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_set_plca_cfg,
+		.policy = ethnl_plca_set_cfg_policy,
+		.maxattr = ARRAY_SIZE(ethnl_plca_set_cfg_policy) - 1,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_PLCA_GET_STATUS,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+		.policy = ethnl_plca_get_status_policy,
+		.maxattr = ARRAY_SIZE(ethnl_plca_get_status_policy) - 1,
+	},
+
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 1bfd374f9718..c0ed1a6d0833 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -346,6 +346,8 @@ extern const struct ethnl_request_ops ethnl_stats_request_ops;
 extern const struct ethnl_request_ops ethnl_phc_vclocks_request_ops;
 extern const struct ethnl_request_ops ethnl_module_request_ops;
 extern const struct ethnl_request_ops ethnl_pse_request_ops;
+extern const struct ethnl_request_ops ethnl_plca_cfg_request_ops;
+extern const struct ethnl_request_ops ethnl_plca_status_request_ops;
 
 extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
 extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];
@@ -386,6 +388,9 @@ extern const struct nla_policy ethnl_module_get_policy[ETHTOOL_A_MODULE_HEADER +
 extern const struct nla_policy ethnl_module_set_policy[ETHTOOL_A_MODULE_POWER_MODE_POLICY + 1];
 extern const struct nla_policy ethnl_pse_get_policy[ETHTOOL_A_PSE_HEADER + 1];
 extern const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1];
+extern const struct nla_policy ethnl_plca_get_cfg_policy[ETHTOOL_A_PLCA_HEADER + 1];
+extern const struct nla_policy ethnl_plca_set_cfg_policy[ETHTOOL_A_PLCA_MAX + 1];
+extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADER + 1];
 
 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
@@ -406,6 +411,7 @@ int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_set_fec(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_module(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_pse(struct sk_buff *skb, struct genl_info *info);
+int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info);
 
 extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
new file mode 100644
index 000000000000..0282acab1c4d
--- /dev/null
+++ b/net/ethtool/plca.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/phy.h>
+#include <linux/ethtool_netlink.h>
+
+#include "netlink.h"
+#include "common.h"
+
+struct plca_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct plca_reply_data {
+	struct ethnl_reply_data		base;
+	struct phy_plca_cfg		plca_cfg;
+	struct phy_plca_status		plca_st;
+};
+
+#define PLCA_REPDATA(__reply_base) \
+	container_of(__reply_base, struct plca_reply_data, base)
+
+// PLCA get configuration message ------------------------------------------- //
+
+const struct nla_policy ethnl_plca_get_cfg_policy[] = {
+	[ETHTOOL_A_PLCA_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int plca_get_cfg_prepare_data(const struct ethnl_req_info *req_base,
+				     struct ethnl_reply_data *reply_base,
+				     struct genl_info *info)
+{
+	struct plca_reply_data *data = PLCA_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	const struct ethtool_phy_ops *ops;
+	int ret;
+
+	// check that the PHY device is available and connected
+	if (!dev->phydev) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	// note: rtnl_lock is held already by ethnl_default_doit
+	ops = ethtool_phy_ops;
+	if (!ops || !ops->get_plca_cfg) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto out;
+
+	ret = ops->get_plca_cfg(dev->phydev, &data->plca_cfg);
+	if (ret < 0)
+		goto out;
+
+	ethnl_ops_complete(dev);
+
+out:
+	return ret;
+}
+
+static int plca_get_cfg_reply_size(const struct ethnl_req_info *req_base,
+				   const struct ethnl_reply_data *reply_base)
+{
+	return nla_total_size(sizeof(u16)) +	/* _VERSION */
+	       nla_total_size(sizeof(u8)) +	/* _ENABLED */
+	       nla_total_size(sizeof(u8)) +	/* _STATUS  */
+	       nla_total_size(sizeof(u8)) +	/* _NODE_CNT */
+	       nla_total_size(sizeof(u8)) +	/* _NODE_ID */
+	       nla_total_size(sizeof(u8)) +	/* _TO_TIMER */
+	       nla_total_size(sizeof(u8)) +	/* _BURST_COUNT */
+	       nla_total_size(sizeof(u8));	/* _BURST_TIMER */
+}
+
+static int plca_get_cfg_fill_reply(struct sk_buff *skb,
+				   const struct ethnl_req_info *req_base,
+				   const struct ethnl_reply_data *reply_base)
+{
+	const struct plca_reply_data *data = PLCA_REPDATA(reply_base);
+	const struct phy_plca_cfg *plca = &data->plca_cfg;
+
+	if ((plca->version >= 0 &&
+	     nla_put_u16(skb, ETHTOOL_A_PLCA_VERSION, (u16)plca->version)) ||
+	    (plca->enabled >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_ENABLED, !!plca->enabled)) ||
+	    (plca->node_id >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_NODE_ID, (u8)plca->node_id)) ||
+	    (plca->node_cnt >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_NODE_CNT, (u8)plca->node_cnt)) ||
+	    (plca->to_tmr >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_TO_TMR, (u8)plca->to_tmr)) ||
+	    (plca->burst_cnt >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_BURST_CNT, (u8)plca->burst_cnt)) ||
+	    (plca->burst_tmr >= 0 &&
+	     nla_put_u8(skb, ETHTOOL_A_PLCA_BURST_TMR, (u8)plca->burst_tmr)))
+		return -EMSGSIZE;
+
+	return 0;
+};
+
+const struct ethnl_request_ops ethnl_plca_cfg_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PLCA_GET_CFG,
+	.reply_cmd		= ETHTOOL_MSG_PLCA_GET_CFG_REPLY,
+	.hdr_attr		= ETHTOOL_A_PLCA_HEADER,
+	.req_info_size		= sizeof(struct plca_req_info),
+	.reply_data_size	= sizeof(struct plca_reply_data),
+
+	.prepare_data		= plca_get_cfg_prepare_data,
+	.reply_size		= plca_get_cfg_reply_size,
+	.fill_reply		= plca_get_cfg_fill_reply,
+};
+
+// PLCA set configuration message ------------------------------------------- //
+
+const struct nla_policy ethnl_plca_set_cfg_policy[] = {
+	[ETHTOOL_A_PLCA_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_PLCA_ENABLED]	= { .type = NLA_U8 },
+	[ETHTOOL_A_PLCA_NODE_ID]	= { .type = NLA_U8 },
+	[ETHTOOL_A_PLCA_NODE_CNT]	= { .type = NLA_U8 },
+	[ETHTOOL_A_PLCA_TO_TMR]		= { .type = NLA_U8 },
+	[ETHTOOL_A_PLCA_BURST_CNT]	= { .type = NLA_U8 },
+	[ETHTOOL_A_PLCA_BURST_TMR]	= { .type = NLA_U8 },
+};
+
+int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
+{
+	struct ethnl_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
+	const struct ethtool_phy_ops *ops;
+	struct phy_plca_cfg plca_cfg;
+	struct net_device *dev;
+
+	bool mod = false;
+	int ret;
+
+	ret = ethnl_parse_header_dev_get(&req_info,
+					 tb[ETHTOOL_A_PLCA_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	dev = req_info.dev;
+
+	// check that the PHY device is available and connected
+	rtnl_lock();
+
+	if (!dev->phydev) {
+		ret = -EOPNOTSUPP;
+		goto out_rtnl;
+	}
+
+	ops = ethtool_phy_ops;
+	if (!ops || !ops->set_plca_cfg) {
+		ret = -EOPNOTSUPP;
+		goto out_rtnl;
+	}
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto out_rtnl;
+
+	memset(&plca_cfg, 0xFF, sizeof(plca_cfg));
+
+	if (tb[ETHTOOL_A_PLCA_ENABLED]) {
+		plca_cfg.enabled = !!nla_get_u8(tb[ETHTOOL_A_PLCA_ENABLED]);
+		mod = true;
+	}
+
+	if (tb[ETHTOOL_A_PLCA_NODE_ID]) {
+		plca_cfg.node_id = nla_get_u8(tb[ETHTOOL_A_PLCA_NODE_ID]);
+		mod = true;
+	}
+
+	if (tb[ETHTOOL_A_PLCA_NODE_CNT]) {
+		plca_cfg.node_cnt = nla_get_u8(tb[ETHTOOL_A_PLCA_NODE_CNT]);
+		mod = true;
+	}
+
+	if (tb[ETHTOOL_A_PLCA_TO_TMR]) {
+		plca_cfg.to_tmr = nla_get_u8(tb[ETHTOOL_A_PLCA_TO_TMR]);
+		mod = true;
+	}
+
+	if (tb[ETHTOOL_A_PLCA_BURST_CNT]) {
+		plca_cfg.burst_cnt = nla_get_u8(tb[ETHTOOL_A_PLCA_BURST_CNT]);
+		mod = true;
+	}
+
+	if (tb[ETHTOOL_A_PLCA_BURST_TMR]) {
+		plca_cfg.burst_tmr = nla_get_u8(tb[ETHTOOL_A_PLCA_BURST_TMR]);
+		mod = true;
+	}
+
+	ret = 0;
+	if (!mod)
+		goto out_ops;
+
+	ret = ops->set_plca_cfg(dev->phydev, info->extack, &plca_cfg);
+
+	if (ret < 0)
+		goto out_ops;
+
+	ethtool_notify(dev, ETHTOOL_MSG_PLCA_NTF, NULL);
+
+out_ops:
+	ethnl_ops_complete(dev);
+out_rtnl:
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info);
+
+	return ret;
+}
+
+// PLCA get status message -------------------------------------------------- //
+
+const struct nla_policy ethnl_plca_get_status_policy[] = {
+	[ETHTOOL_A_PLCA_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int plca_get_status_prepare_data(const struct ethnl_req_info *req_base,
+					struct ethnl_reply_data *reply_base,
+					struct genl_info *info)
+{
+	struct plca_reply_data *data = PLCA_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	const struct ethtool_phy_ops *ops;
+	int ret;
+
+	// check that the PHY device is available and connected
+	if (!dev->phydev) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	// note: rtnl_lock is held already by ethnl_default_doit
+	ops = ethtool_phy_ops;
+	if (!ops || !ops->get_plca_status) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		goto out;
+
+	ret = ops->get_plca_status(dev->phydev, &data->plca_st);
+	if (ret < 0)
+		goto out;
+
+	ethnl_ops_complete(dev);
+out:
+	return ret;
+}
+
+static int plca_get_status_reply_size(const struct ethnl_req_info *req_base,
+				      const struct ethnl_reply_data *reply_base)
+{
+	return nla_total_size(sizeof(u8));	/* _STATUS */
+}
+
+static int plca_get_status_fill_reply(struct sk_buff *skb,
+				      const struct ethnl_req_info *req_base,
+				      const struct ethnl_reply_data *reply_base)
+{
+	const struct plca_reply_data *data = PLCA_REPDATA(reply_base);
+	const u8 status = data->plca_st.pst;
+
+	if (nla_put_u8(skb, ETHTOOL_A_PLCA_STATUS, !!status))
+		return -EMSGSIZE;
+
+	return 0;
+};
+
+const struct ethnl_request_ops ethnl_plca_status_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_PLCA_GET_STATUS,
+	.reply_cmd		= ETHTOOL_MSG_PLCA_GET_STATUS_REPLY,
+	.hdr_attr		= ETHTOOL_A_PLCA_HEADER,
+	.req_info_size		= sizeof(struct plca_req_info),
+	.reply_data_size	= sizeof(struct plca_reply_data),
+
+	.prepare_data		= plca_get_status_prepare_data,
+	.reply_size		= plca_get_status_reply_size,
+	.fill_reply		= plca_get_status_fill_reply,
+};
-- 
2.35.1

[PATCH v3 net-next 2/4] drivers/net/phy: add the link modes for the 10BASE-T1S Ethernet PHY

[Piergiorgio Beruto]

This patch adds the link modes for the IEEE 802.3cg Clause 147 10BASE-T1S
Ethernet PHY. According to the specifications, the 10BASE-T1S supports
Point-To-Point Full-Duplex, Point-To-Point Half-Duplex and/or
Point-To-Multipoint (AKA Multi-Drop) Hal-Duplex operations.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
 Documentation/networking/ethtool-netlink.rst | 133 +++++++++++++++++++
 drivers/net/phy/phy-core.c                   |   5 +-
 drivers/net/phy/phylink.c                    |   6 +-
 include/uapi/linux/ethtool.h                 |   3 +
 net/ethtool/common.c                         |   8 ++
 5 files changed, 153 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index bede24ef44fd..7649716bc532 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1687,6 +1687,136 @@ to control PoDL PSE Admin functions. This option is implementing
 ``IEEE 802.3-2018`` 30.15.1.2.1 acPoDLPSEAdminControl. See
 ``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` for supported values.
 
+PLCA_GET_CFG
+============
+
+Gets PLCA RS attributes.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_PLCA_HEADER``              nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+  ======================================  ======  =============================
+  ``ETHTOOL_A_PLCA_HEADER``               nested  reply header
+  ``ETHTOOL_A_PLCA_VERSION``              u16     Supported PLCA management
+                                                  interface standard/version
+  ``ETHTOOL_A_PLCA_ENABLED``              u8      PLCA Admin State
+  ``ETHTOOL_A_PLCA_NODE_ID``              u8      PLCA unique local node ID
+  ``ETHTOOL_A_PLCA_NODE_CNT``             u8      Number of PLCA nodes on the
+                                                  netkork, including the
+                                                  coordinator
+  ``ETHTOOL_A_PLCA_TO_TMR``               u8      Transmit Opportunity Timer
+                                                  value in bit-times (BT)
+  ``ETHTOOL_A_PLCA_BURST_CNT``            u8      Number of additional packets
+                                                  the node is allowed to send
+                                                  within a single TO
+  ``ETHTOOL_A_PLCA_BURST_TMR``            u8      Time to wait for the MAC to
+                                                  transmit a new frame before
+                                                  terminating the burst
+  ======================================  ======  =============================
+
+When set, the optional ``ETHTOOL_A_PLCA_VERSION`` attribute indicates which
+standard and version the PLCA management interface complies to. When not set,
+the interface is vendor-specific and (possibly) supplied by the driver.
+The OPEN Alliance SIG specifies a standard register map for 10BASE-T1S PHYs
+embedding the PLCA Reconcialiation Sublayer. See "10BASE-T1S PLCA Management
+Registers" at https://www.opensig.org/about/specifications/. When this standard
+is supported, ETHTOOL_A_PLCA_VERSION is reported as 0Axx where 'xx' denotes the
+map version (see Table A.1.0 — IDVER bits assignment).
+
+When set, the optional ``ETHTOOL_A_PLCA_ENABLED`` attribute indicates the
+administrative state of the PLCA RS. When not set, the node operates in "plain"
+CSMA/CD mode. This option is corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.1
+aPLCAAdminState / 30.16.1.2.1 acPLCAAdminControl.
+
+When set, the optional ``ETHTOOL_A_PLCA_NODE_ID`` attribute indicates the
+configured local node ID of the PHY. This ID determines which transmit
+opportunity (TO) is reseverd for the node to transmit into. This option is
+corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.4 aPLCALocalNodeID.
+
+When set, the optional ``ETHTOOL_A_PLCA_NODE_CNT`` attribute indicates the
+configured maximum number of PLCA nodes on the mixing-segment. This number
+determines the total number of transmit opportunities generated during a
+PLCA cycle. This attribute is relevant only for the PLCA coordinator, which is
+the node with aPLCALocalNodeID set to 0. Follower nodes ignore this setting.
+This option is corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.3
+aPLCANodeCount.
+
+When set, the optional ``ETHTOOL_A_PLCA_TO_TMR`` attribute indicates the
+configured value of the transmit opportunity timer in bit-times. This value
+must be set equal across all nodes sharing the medium for PLCA to work
+correctly. This option is corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.5
+aPLCATransmitOpportunityTimer.
+
+When set, the optional ``ETHTOOL_A_PLCA_BURST_CNT`` attribute indicates the
+configured number of extra packets that the node is allowed to send during a
+single transmit opportunity. By default, this attribute is 0, meaning that
+the node can only send a sigle frame per TO. When greater than 0, the PLCA RS
+keeps the TO after any transmission, waiting for the MAC to send a new frame
+for up to aPLCABurstTimer BTs. This can only happen a number of times per PLCA
+cycle up to the value of this parameter. After that, the burst is over and the
+normal counting of TOs resumes. This option is corresponding to
+``IEEE 802.3cg-2019`` 30.16.1.1.6 aPLCAMaxBurstCount.
+
+When set, the optional ``ETHTOOL_A_PLCA_BURST_TMR`` attribute indicates how
+many bit-times the PLCA RS waits for the MAC to initiate a new transmission
+when aPLCAMaxBurstCount is greater than 0. If the MAC fails to send a new
+frame within this time, the burst ends and the counting of TOs resumes.
+Otherwise, the new frame is sent as part of the current burst. This option
+is corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.7 aPLCABurstTimer.
+
+PLCA_SET_CFG
+============
+
+Sets PLCA RS parameters.
+
+Request contents:
+
+  ======================================  ======  =============================
+  ``ETHTOOL_A_PLCA_HEADER``               nested  request header
+  ``ETHTOOL_A_PLCA_ENABLED``              u8      PLCA Admin State
+  ``ETHTOOL_A_PLCA_NODE_ID``              u8      PLCA unique local node ID
+  ``ETHTOOL_A_PLCA_NODE_CNT``             u8      Number of PLCA nodes on the
+                                                  netkork, including the
+                                                  coordinator
+  ``ETHTOOL_A_PLCA_TO_TMR``               u8      Transmit Opportunity Timer
+                                                  value in bit-times (BT)
+  ``ETHTOOL_A_PLCA_BURST_CNT``            u8      Number of additional packets
+                                                  the node is allowed to send
+                                                  within a single TO
+  ``ETHTOOL_A_PLCA_BURST_TMR``            u8      Time to wait for the MAC to
+                                                  transmit a new frame before
+                                                  terminating the burst
+  ======================================  ======  =============================
+
+For a description of each attribute, see ``PLCA_GET_CFG``.
+
+PLCA_GET_STATUS
+===============
+
+Gets PLCA RS status information.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_PLCA_HEADER``              nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+  ======================================  ======  =============================
+  ``ETHTOOL_A_PLCA_HEADER``               nested  reply header
+  ``ETHTOOL_A_PLCA_STATUS``               u8      PLCA RS operational status
+  ======================================  ======  =============================
+
+When set, the ``ETHTOOL_A_PLCA_STATUS`` attribute indicates whether the node is
+detecting the presence of the BEACON on the network. This flag is
+corresponding to ``IEEE 802.3cg-2019`` 30.16.1.1.2 aPLCAStatus.
+
 Request translation
 ===================
 
@@ -1788,4 +1918,7 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_PHC_VCLOCKS_GET``
   n/a                                 ``ETHTOOL_MSG_MODULE_GET``
   n/a                                 ``ETHTOOL_MSG_MODULE_SET``
+  n/a                                 ``ETHTOOL_MSG_PLCA_GET_CFG``
+  n/a                                 ``ETHTOOL_MSG_PLCA_SET_CFG``
+  n/a                                 ``ETHTOOL_MSG_PLCA_GET_STATUS``
   =================================== =====================================
diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 5d08c627a516..a64186dc53f8 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -13,7 +13,7 @@
  */
 const char *phy_speed_to_str(int speed)
 {
-	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 99,
+	BUILD_BUG_ON_MSG(__ETHTOOL_LINK_MODE_MASK_NBITS != 102,
 		"Enum ethtool_link_mode_bit_indices and phylib are out of sync. "
 		"If a speed or mode has been added please update phy_speed_to_str "
 		"and the PHY settings array.\n");
@@ -260,6 +260,9 @@ static const struct phy_setting settings[] = {
 	PHY_SETTING(     10, FULL,     10baseT_Full		),
 	PHY_SETTING(     10, HALF,     10baseT_Half		),
 	PHY_SETTING(     10, FULL,     10baseT1L_Full		),
+	PHY_SETTING(     10, FULL,     10baseT1S_Full		),
+	PHY_SETTING(     10, HALF,     10baseT1S_Half		),
+	PHY_SETTING(     10, HALF,     10baseT1S_P2MP_Half	),
 };
 #undef PHY_SETTING
 
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 09cc65c0da93..319790221d7f 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -241,12 +241,16 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps)
 	if (caps & MAC_ASYM_PAUSE)
 		__set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, linkmodes);
 
-	if (caps & MAC_10HD)
+	if (caps & MAC_10HD) {
 		__set_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, linkmodes);
+		__set_bit(ETHTOOL_LINK_MODE_10baseT1S_Half_BIT, linkmodes);
+		__set_bit(ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT, linkmodes);
+	}
 
 	if (caps & MAC_10FD) {
 		__set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, linkmodes);
 		__set_bit(ETHTOOL_LINK_MODE_10baseT1L_Full_BIT, linkmodes);
+		__set_bit(ETHTOOL_LINK_MODE_10baseT1S_Full_BIT, linkmodes);
 	}
 
 	if (caps & MAC_100HD) {
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 58e587ba0450..5f414deacf23 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1741,6 +1741,9 @@ enum ethtool_link_mode_bit_indices {
 	ETHTOOL_LINK_MODE_800000baseDR8_2_Full_BIT	 = 96,
 	ETHTOOL_LINK_MODE_800000baseSR8_Full_BIT	 = 97,
 	ETHTOOL_LINK_MODE_800000baseVR8_Full_BIT	 = 98,
+	ETHTOOL_LINK_MODE_10baseT1S_Full_BIT		 = 99,
+	ETHTOOL_LINK_MODE_10baseT1S_Half_BIT		 = 100,
+	ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT	 = 101,
 
 	/* must be last entry */
 	__ETHTOOL_LINK_MODE_MASK_NBITS
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 21cfe8557205..c586db0c5e68 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -208,6 +208,9 @@ const char link_mode_names[][ETH_GSTRING_LEN] = {
 	__DEFINE_LINK_MODE_NAME(800000, DR8_2, Full),
 	__DEFINE_LINK_MODE_NAME(800000, SR8, Full),
 	__DEFINE_LINK_MODE_NAME(800000, VR8, Full),
+	__DEFINE_LINK_MODE_NAME(10, T1S, Full),
+	__DEFINE_LINK_MODE_NAME(10, T1S, Half),
+	__DEFINE_LINK_MODE_NAME(10, T1S_P2MP, Half),
 };
 static_assert(ARRAY_SIZE(link_mode_names) == __ETHTOOL_LINK_MODE_MASK_NBITS);
 
@@ -244,6 +247,8 @@ static_assert(ARRAY_SIZE(link_mode_names) == __ETHTOOL_LINK_MODE_MASK_NBITS);
 #define __LINK_MODE_LANES_X		1
 #define __LINK_MODE_LANES_FX		1
 #define __LINK_MODE_LANES_T1L		1
+#define __LINK_MODE_LANES_T1S		1
+#define __LINK_MODE_LANES_T1S_P2MP	1
 #define __LINK_MODE_LANES_VR8		8
 #define __LINK_MODE_LANES_DR8_2		8
 
@@ -366,6 +371,9 @@ const struct link_mode_info link_mode_params[] = {
 	__DEFINE_LINK_MODE_PARAMS(800000, DR8_2, Full),
 	__DEFINE_LINK_MODE_PARAMS(800000, SR8, Full),
 	__DEFINE_LINK_MODE_PARAMS(800000, VR8, Full),
+	__DEFINE_LINK_MODE_PARAMS(10, T1S, Full),
+	__DEFINE_LINK_MODE_PARAMS(10, T1S, Half),
+	__DEFINE_LINK_MODE_PARAMS(10, T1S_P2MP, Half),
 };
 static_assert(ARRAY_SIZE(link_mode_params) == __ETHTOOL_LINK_MODE_MASK_NBITS);
 
-- 
2.35.1

[PATCH v3 net-next 3/4] drivers/net/phy: add connection between ethtool and phylib for PLCA

[Piergiorgio Beruto]

This patch adds the required connection between netlink ethtool and
phylib to resolve PLCA get/set config and get status messages.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
 drivers/net/phy/phy.c | 163 +++++++++++++++++++++++++++++++++++++++---
 include/linux/phy.h   |  17 ++++-
 2 files changed, 168 insertions(+), 12 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 99e3497b6aa1..6bea928e405b 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -544,36 +544,181 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
 EXPORT_SYMBOL(phy_ethtool_get_stats);
 
 /**
+ * phy_ethtool_get_plca_cfg - Get PLCA RS configuration
  *
+ * @phydev: the phy_device struct
+ * @plca_cfg: where to store the retrieved configuration
  */
-int phy_ethtool_get_plca_cfg(struct phy_device *dev,
+int phy_ethtool_get_plca_cfg(struct phy_device *phydev,
 			     struct phy_plca_cfg *plca_cfg)
 {
-	// TODO
-	return 0;
+	int ret;
+
+	if (!phydev->drv) {
+		ret = -EIO;
+		goto out;
+	}
+
+	if (!phydev->drv->get_plca_cfg) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	memset(plca_cfg, 0xFF, sizeof(*plca_cfg));
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->get_plca_cfg(phydev, plca_cfg);
+
+	if (ret)
+		goto out_drv;
+
+out_drv:
+	mutex_unlock(&phydev->lock);
+out:
+	return ret;
 }
 EXPORT_SYMBOL(phy_ethtool_get_plca_cfg);
 
 /**
+ * phy_ethtool_set_plca_cfg - Set PLCA RS configuration
  *
+ * @phydev: the phy_device struct
+ * @extack: extack for reporting useful error messages
+ * @plca_cfg: new PLCA configuration to apply
  */
-int phy_ethtool_set_plca_cfg(struct phy_device *dev,
+int phy_ethtool_set_plca_cfg(struct phy_device *phydev,
 			     struct netlink_ext_ack *extack,
 			     const struct phy_plca_cfg *plca_cfg)
 {
-	// TODO
-	return 0;
+	int ret;
+	struct phy_plca_cfg *curr_plca_cfg = 0;
+
+	if (!phydev->drv) {
+		ret = -EIO;
+		goto out;
+	}
+
+	if (!phydev->drv->set_plca_cfg ||
+	    !phydev->drv->get_plca_cfg) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	curr_plca_cfg = kmalloc(sizeof(*curr_plca_cfg), GFP_KERNEL);
+	memset(curr_plca_cfg, 0xFF, sizeof(*curr_plca_cfg));
+
+	mutex_lock(&phydev->lock);
+
+	ret = phydev->drv->get_plca_cfg(phydev, curr_plca_cfg);
+	if (ret)
+		goto out_drv;
+
+	if (curr_plca_cfg->enabled < 0 && plca_cfg->enabled >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'enable' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	if (curr_plca_cfg->node_id < 0 && plca_cfg->node_id >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'local node ID' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	if (curr_plca_cfg->node_cnt < 0 && plca_cfg->node_cnt >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'node count' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	if (curr_plca_cfg->to_tmr < 0 && plca_cfg->to_tmr >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'TO timer' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	if (curr_plca_cfg->burst_cnt < 0 && plca_cfg->burst_cnt >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'burst count' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	if (curr_plca_cfg->burst_tmr < 0 && plca_cfg->burst_tmr >= 0) {
+		NL_SET_ERR_MSG(extack,
+			       "PHY does not support changing the PLCA 'burst timer' attribute");
+		ret = -EINVAL;
+		goto out_drv;
+	}
+
+	// if enabling PLCA, perform additional sanity checks
+	if (plca_cfg->enabled > 0) {
+		if (!linkmode_test_bit(ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT,
+				       phydev->advertising)) {
+			ret = -EOPNOTSUPP;
+			NL_SET_ERR_MSG(extack,
+				       "Point to Multi-Point mode is not enabled");
+		}
+
+		// allow setting node_id concurrently with enabled
+		if (plca_cfg->node_id >= 0)
+			curr_plca_cfg->node_id = plca_cfg->node_id;
+
+		if (curr_plca_cfg->node_id >= 255) {
+			NL_SET_ERR_MSG(extack, "PLCA node ID is not set");
+			ret = -EINVAL;
+			goto out_drv;
+		}
+	}
+
+	ret = phydev->drv->set_plca_cfg(phydev, plca_cfg);
+	if (ret)
+		goto out_drv;
+
+out_drv:
+	kfree(curr_plca_cfg);
+	mutex_unlock(&phydev->lock);
+out:
+	return ret;
+
 }
 EXPORT_SYMBOL(phy_ethtool_set_plca_cfg);
 
 /**
+ * phy_ethtool_get_plca_status - Get PLCA RS status information
  *
+ * @phydev: the phy_device struct
+ * @plca_st: where to store the retrieved status information
  */
-int phy_ethtool_get_plca_status(struct phy_device *dev,
+int phy_ethtool_get_plca_status(struct phy_device *phydev,
 				struct phy_plca_status *plca_st)
 {
-	// TODO
-	return 0;
+	int ret;
+
+	if (!phydev->drv) {
+		ret = -EIO;
+		goto out;
+	}
+
+	if (!phydev->drv->get_plca_status) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->get_plca_status(phydev, plca_st);
+
+	if (ret)
+		goto out_drv;
+
+out_drv:
+	mutex_unlock(&phydev->lock);
+out:
+	return ret;
 }
 EXPORT_SYMBOL(phy_ethtool_get_plca_status);
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index ab2c134d0a05..49d0488bf480 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1036,6 +1036,17 @@ struct phy_driver {
 	int (*get_sqi)(struct phy_device *dev);
 	/** @get_sqi_max: Get the maximum signal quality indication */
 	int (*get_sqi_max)(struct phy_device *dev);
+
+	/* PLCA RS interface */
+	/** @get_plca_cfg: Return the current PLCA configuration */
+	int (*get_plca_cfg)(struct phy_device *dev,
+			    struct phy_plca_cfg *plca_cfg);
+	/** @set_plca_cfg: Set the PLCA configuration */
+	int (*set_plca_cfg)(struct phy_device *dev,
+			    const struct phy_plca_cfg *plca_cfg);
+	/** @get_plca_status: Return the current PLCA status info */
+	int (*get_plca_status)(struct phy_device *dev,
+			       struct phy_plca_status *plca_st);
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)
@@ -1832,12 +1843,12 @@ int phy_ethtool_get_strings(struct phy_device *phydev, u8 *data);
 int phy_ethtool_get_sset_count(struct phy_device *phydev);
 int phy_ethtool_get_stats(struct phy_device *phydev,
 			  struct ethtool_stats *stats, u64 *data);
-int phy_ethtool_get_plca_cfg(struct phy_device *dev,
+int phy_ethtool_get_plca_cfg(struct phy_device *phydev,
 			     struct phy_plca_cfg *plca_cfg);
-int phy_ethtool_set_plca_cfg(struct phy_device *dev,
+int phy_ethtool_set_plca_cfg(struct phy_device *phydev,
 			     struct netlink_ext_ack *extack,
 			     const struct phy_plca_cfg *plca_cfg);
-int phy_ethtool_get_plca_status(struct phy_device *dev,
+int phy_ethtool_get_plca_status(struct phy_device *phydev,
 				struct phy_plca_status *plca_st);
 
 static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
-- 
2.35.1

[PATCH v3 net-next 4/4] drivers/net/phy: add driver for the onsemi NCN26000 10BASE-T1S PHY

[Piergiorgio Beruto]

Add support for the onsemi NCN26000 10BASE-T1S industrial Ethernet PHY.
The driver supports Point-to-Multipoint operation without
auto-negotiation and with link control handling. The PLCA RS support
will be included on a separate patch.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
---
 MAINTAINERS                          |   8 ++
 drivers/net/phy/Kconfig              |   7 +
 drivers/net/phy/Makefile             |   1 +
 drivers/net/phy/mdio-open-alliance.h |  44 ++++++
 drivers/net/phy/ncn26000.c           | 193 +++++++++++++++++++++++++++
 drivers/net/phy/phy-c45.c            | 180 +++++++++++++++++++++++++
 include/linux/phy.h                  |   6 +
 7 files changed, 439 insertions(+)
 create mode 100644 drivers/net/phy/mdio-open-alliance.h
 create mode 100644 drivers/net/phy/ncn26000.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7952243e4b43..09f0bfa3ae64 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15357,6 +15357,13 @@ L:	linux-mips@vger.kernel.org
 S:	Maintained
 F:	arch/mips/boot/dts/ralink/omega2p.dts
 
+ONSEMI ETHERNET PHY DRIVERS
+M:	Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
+L:	netdev@vger.kernel.org
+S:	Supported
+W:	http://www.onsemi.com
+F:	drivers/net/phy/ncn*
+
 OP-TEE DRIVER
 M:	Jens Wiklander <jens.wiklander@linaro.org>
 L:	op-tee@lists.trustedfirmware.org
@@ -16400,6 +16407,7 @@ PLCA RECONCILIATION SUBLAYER (IEEE802.3 Clause 148)
 M:	Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
+F:	drivers/net/phy/mdio-open-alliance.h
 F:	net/ethtool/plca.c
 
 PLDMFW LIBRARY
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index af00cf44cd97..7c466830c611 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -267,6 +267,13 @@ config NATIONAL_PHY
 	help
 	  Currently supports the DP83865 PHY.
 
+config NCN26000_PHY
+	tristate "onsemi 10BASE-T1S Ethernet PHY"
+	help
+	  Adds support for the onsemi 10BASE-T1S Ethernet PHY.
+	  Currently supports the NCN26000 10BASE-T1S Industrial PHY
+	  with MII interface.
+
 config NXP_C45_TJA11XX_PHY
 	tristate "NXP C45 TJA11XX PHYs"
 	depends on PTP_1588_CLOCK_OPTIONAL
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index f7138d3c896b..b5138066ba04 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_MICROCHIP_T1_PHY)	+= microchip_t1.o
 obj-$(CONFIG_MICROSEMI_PHY)	+= mscc/
 obj-$(CONFIG_MOTORCOMM_PHY)	+= motorcomm.o
 obj-$(CONFIG_NATIONAL_PHY)	+= national.o
+obj-$(CONFIG_NCN26000_PHY)	+= ncn26000.o
 obj-$(CONFIG_NXP_C45_TJA11XX_PHY)	+= nxp-c45-tja11xx.o
 obj-$(CONFIG_NXP_TJA11XX_PHY)	+= nxp-tja11xx.o
 obj-$(CONFIG_QSEMI_PHY)		+= qsemi.o
diff --git a/drivers/net/phy/mdio-open-alliance.h b/drivers/net/phy/mdio-open-alliance.h
new file mode 100644
index 000000000000..565f4162611d
--- /dev/null
+++ b/drivers/net/phy/mdio-open-alliance.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mdio-open-alliance.h - definition of OPEN Alliance SIG standard registers
+ */
+
+#ifndef __MDIO_OPEN_ALLIANCE__
+#define __MDIO_OPEN_ALLIANCE__
+
+#include <linux/mdio.h>
+
+/* MDIO Manageable Devices (MMDs). */
+#define MDIO_MMD_OATC14		MDIO_MMD_VEND2
+
+/* Open Alliance TC14 (10BASE-T1S) registers */
+#define MDIO_OATC14_PLCA_IDVER	0xca00  /* PLCA ID and version */
+#define MDIO_OATC14_PLCA_CTRL0	0xca01	/* PLCA Control register 0 */
+#define MDIO_OATC14_PLCA_CTRL1	0xca02	/* PLCA Control register 1 */
+#define MDIO_OATC14_PLCA_STATUS	0xca03	/* PLCA Status register */
+#define MDIO_OATC14_PLCA_TOTMR	0xca04	/* PLCA TO Timer register */
+#define MDIO_OATC14_PLCA_BURST	0xca05	/* PLCA BURST mode register */
+
+/* Open Alliance TC14 PLCA IDVER register */
+#define MDIO_OATC14_PLCA_IDM	0xff00	/* PLCA MAP ID */
+#define MDIO_OATC14_PLCA_VER	0x00ff	/* PLCA MAP version */
+
+/* Open Alliance TC14 PLCA CTRL0 register */
+#define MDIO_OATC14_PLCA_EN	0x8000  /* PLCA enable */
+#define MDIO_OATC14_PLCA_RST	0x4000  /* PLCA reset */
+
+/* Open Alliance TC14 PLCA CTRL1 register */
+#define MDIO_OATC14_PLCA_NCNT	0xff00	/* PLCA node count */
+#define MDIO_OATC14_PLCA_ID	0x00ff	/* PLCA local node ID */
+
+/* Open Alliance TC14 PLCA STATUS register */
+#define MDIO_OATC14_PLCA_PST	0x8000	/* PLCA status indication */
+
+/* Open Alliance TC14 PLCA TOTMR register */
+#define MDIO_OATC14_PLCA_TOT	0x00ff
+
+/* Open Alliance TC14 PLCA BURST register */
+#define MDIO_OATC14_PLCA_MAXBC	0xff00
+#define MDIO_OATC14_PLCA_BTMR	0x00ff
+
+#endif /* __MDIO_OPEN_ALLIANCE__ */
diff --git a/drivers/net/phy/ncn26000.c b/drivers/net/phy/ncn26000.c
new file mode 100644
index 000000000000..9e02c5c55244
--- /dev/null
+++ b/drivers/net/phy/ncn26000.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ *  Driver for the onsemi 10BASE-T1S NCN26000 PHYs family.
+ *
+ * Copyright 2022 onsemi
+ */
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+
+#include "mdio-open-alliance.h"
+
+#define PHY_ID_NCN26000			0x180FF5A1
+
+#define NCN26000_REG_IRQ_CTL            16
+#define NCN26000_REG_IRQ_STATUS         17
+
+// the NCN26000 maps link_ctrl to BMCR_ANENABLE
+#define NCN26000_BCMR_LINK_CTRL_BIT	BMCR_ANENABLE
+
+// the NCN26000 maps link_status to BMSR_ANEGCOMPLETE
+#define NCN26000_BMSR_LINK_STATUS_BIT	BMSR_ANEGCOMPLETE
+
+#define NCN26000_IRQ_LINKST_BIT		BIT(0)
+#define NCN26000_IRQ_PLCAST_BIT		BIT(1)
+#define NCN26000_IRQ_LJABBER_BIT	BIT(2)
+#define NCN26000_IRQ_RJABBER_BIT	BIT(3)
+#define NCN26000_IRQ_PLCAREC_BIT	BIT(4)
+#define NCN26000_IRQ_PHYSCOL_BIT	BIT(5)
+
+#define TO_TMR_DEFAULT			32
+
+struct ncn26000_priv {
+	u16 enabled_irqs;
+};
+
+// module parameter: if set, the link status is derived from the PLCA status
+// default: false
+static bool link_status_plca;
+module_param(link_status_plca, bool, 0644);
+
+// driver callbacks
+
+static int ncn26000_config_init(struct phy_device *phydev)
+{
+	/* HW bug workaround: the default value of the PLCA TO_TIMER should be
+	 * 32, where the current version of NCN26000 reports 24. This will be
+	 * fixed in future PHY versions. For the time being, we force the
+	 * correct default here.
+	 */
+	return phy_write_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_TOTMR,
+			     TO_TMR_DEFAULT);
+}
+
+static int ncn26000_config_aneg(struct phy_device *phydev)
+{
+	// Note: the NCN26000 supports only P2MP link mode. Therefore, AN is not
+	// supported. However, this function is invoked by phylib to enable the
+	// PHY, regardless of the AN support.
+	phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
+	phydev->mdix = ETH_TP_MDI;
+
+	// bring up the link
+	return phy_write(phydev, MII_BMCR, NCN26000_BCMR_LINK_CTRL_BIT);
+}
+
+static int ncn26000_get_features(struct phy_device *phydev)
+{
+	linkmode_zero(phydev->supported);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_MII_BIT, phydev->supported);
+
+	linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT1S_P2MP_Half_BIT,
+			 phydev->supported);
+
+	linkmode_copy(phydev->advertising, phydev->supported);
+	return 0;
+}
+
+static int ncn26000_read_status(struct phy_device *phydev)
+{
+	// The NCN26000 reports NCN26000_LINK_STATUS_BIT if the link status of
+	// the PHY is up. It further reports the logical AND of the link status
+	// and the PLCA status in the BMSR_LSTATUS bit. Thus, report the link
+	// status by testing the appropriate BMSR bit according to the module's
+	// parameter configuration.
+	const int lstatus_flag = link_status_plca ?
+		BMSR_LSTATUS : NCN26000_BMSR_LINK_STATUS_BIT;
+
+	int ret;
+
+	ret = phy_read(phydev, MII_BMSR);
+	if (unlikely(ret < 0))
+		return ret;
+
+	// update link status
+	phydev->link = (ret & lstatus_flag) ? 1 : 0;
+
+	// handle more IRQs here
+
+	return 0;
+}
+
+static irqreturn_t ncn26000_handle_interrupt(struct phy_device *phydev)
+{
+	const struct ncn26000_priv *const priv = phydev->priv;
+	int ret;
+
+	// clear the latched bits in MII_BMSR
+	phy_read(phydev, MII_BMSR);
+
+	// read and aknowledge the IRQ status register
+	ret = phy_read(phydev, NCN26000_REG_IRQ_STATUS);
+
+	if (unlikely(ret < 0) || (ret & priv->enabled_irqs) == 0)
+		return IRQ_NONE;
+
+	phy_trigger_machine(phydev);
+	return IRQ_HANDLED;
+}
+
+static int ncn26000_config_intr(struct phy_device *phydev)
+{
+	int ret;
+	struct ncn26000_priv *priv = phydev->priv;
+
+	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
+		// acknowledge IRQs
+		ret = phy_read(phydev, NCN26000_REG_IRQ_STATUS);
+		if (ret < 0)
+			return ret;
+
+		// get link status notifications
+		priv->enabled_irqs = NCN26000_IRQ_LINKST_BIT;
+	} else {
+		// disable all IRQs
+		priv->enabled_irqs = 0;
+	}
+
+	ret = phy_write(phydev, NCN26000_REG_IRQ_CTL, priv->enabled_irqs);
+	if (ret != 0)
+		return ret;
+
+	return 0;
+}
+
+static int ncn26000_probe(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct ncn26000_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	phydev->priv = priv;
+
+	return 0;
+}
+
+static struct phy_driver ncn26000_driver[] = {
+	{
+		PHY_ID_MATCH_MODEL(PHY_ID_NCN26000),
+		.name			= "NCN26000",
+		.probe                  = ncn26000_probe,
+		.get_features		= ncn26000_get_features,
+		.config_init            = ncn26000_config_init,
+		.config_intr            = ncn26000_config_intr,
+		.config_aneg		= ncn26000_config_aneg,
+		.read_status		= ncn26000_read_status,
+		.handle_interrupt       = ncn26000_handle_interrupt,
+		.get_plca_cfg		= genphy_c45_plca_get_cfg,
+		.set_plca_cfg		= genphy_c45_plca_set_cfg,
+		.get_plca_status	= genphy_c45_plca_get_status,
+		.soft_reset             = genphy_soft_reset,
+	},
+};
+
+module_phy_driver(ncn26000_driver);
+
+static struct mdio_device_id __maybe_unused ncn26000_tbl[] = {
+	{ PHY_ID_MATCH_MODEL(PHY_ID_NCN26000) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, ncn26000_tbl);
+
+MODULE_AUTHOR("Piergiorgio Beruto");
+MODULE_DESCRIPTION("onsemi 10BASE-T1S PHY driver");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index a87a4b3ffce4..dace5d3b29ad 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -8,6 +8,8 @@
 #include <linux/mii.h>
 #include <linux/phy.h>
 
+#include "mdio-open-alliance.h"
+
 /**
  * genphy_c45_baset1_able - checks if the PMA has BASE-T1 extended abilities
  * @phydev: target phy_device struct
@@ -931,6 +933,184 @@ int genphy_c45_fast_retrain(struct phy_device *phydev, bool enable)
 }
 EXPORT_SYMBOL_GPL(genphy_c45_fast_retrain);
 
+/**
+ * genphy_c45_plca_get_cfg - get PLCA configuration from standard registers
+ * @phydev: target phy_device struct
+ * @plca_cfg: output structure to store the PLCA configuration
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ *   Management Registers specifications, this function can be used to retrieve
+ *   the current PLCA configuration from the standard registers in MMD 31.
+ */
+int genphy_c45_plca_get_cfg(struct phy_device *phydev,
+			    struct phy_plca_cfg *plca_cfg)
+{
+	int ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_IDVER);
+	if (ret < 0)
+		return ret;
+
+	plca_cfg->version = ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_CTRL0);
+	if (ret < 0)
+		return ret;
+
+	plca_cfg->enabled = !!(ret & MDIO_OATC14_PLCA_EN);
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_CTRL1);
+	if (ret < 0)
+		return ret;
+
+	plca_cfg->node_cnt = (ret & MDIO_OATC14_PLCA_NCNT) >> 8;
+	plca_cfg->node_id = (ret & MDIO_OATC14_PLCA_ID);
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_TOTMR);
+	if (ret < 0)
+		return ret;
+
+	plca_cfg->to_tmr = ret & MDIO_OATC14_PLCA_TOT;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_BURST);
+	if (ret < 0)
+		return ret;
+
+	plca_cfg->burst_cnt = (ret & MDIO_OATC14_PLCA_MAXBC) >> 8;
+	plca_cfg->burst_tmr = (ret & MDIO_OATC14_PLCA_BTMR);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_get_cfg);
+
+/**
+ * genphy_c45_plca_set_cfg - set PLCA configuration using standard registers
+ * @phydev: target phy_device struct
+ * @plca_cfg: structure containing the PLCA configuration. Fields set to -1 are
+ * not to be changed.
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ *   Management Registers specifications, this function can be used to modify
+ *   the PLCA configuration using the standard registers in MMD 31.
+ */
+int genphy_c45_plca_set_cfg(struct phy_device *phydev,
+			    const struct phy_plca_cfg *plca_cfg)
+{
+	int ret;
+	u16 val;
+
+	// PLCA IDVER is read-only
+	if (plca_cfg->version >= 0)
+		return -EINVAL;
+
+	// first of all, disable PLCA if required
+	if (plca_cfg->enabled == 0) {
+		ret = phy_clear_bits_mmd(phydev, MDIO_MMD_OATC14,
+					 MDIO_OATC14_PLCA_CTRL0,
+					 MDIO_OATC14_PLCA_EN);
+
+		if (ret < 0)
+			return ret;
+	}
+
+	if (plca_cfg->node_cnt >= 0 || plca_cfg->node_id >= 0) {
+		if (plca_cfg->node_cnt < 0 || plca_cfg->node_id < 0) {
+			ret = phy_read_mmd(phydev, MDIO_MMD_OATC14,
+					   MDIO_OATC14_PLCA_CTRL1);
+
+			if (ret < 0)
+				return ret;
+
+			val = ret;
+		}
+
+		if (plca_cfg->node_cnt >= 0)
+			val = (val & ~MDIO_OATC14_PLCA_NCNT) |
+			      (plca_cfg->node_cnt << 8);
+
+		if (plca_cfg->node_id >= 0)
+			val = (val & ~MDIO_OATC14_PLCA_ID) |
+			      (plca_cfg->node_id);
+
+		ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+				    MDIO_OATC14_PLCA_CTRL1, val);
+
+		if (ret < 0)
+			return ret;
+	}
+
+	if (plca_cfg->to_tmr >= 0) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+				    MDIO_OATC14_PLCA_TOTMR,
+				    plca_cfg->to_tmr);
+
+		if (ret < 0)
+			return ret;
+	}
+
+	if (plca_cfg->burst_cnt >= 0 || plca_cfg->burst_tmr >= 0) {
+		if (plca_cfg->burst_cnt < 0 || plca_cfg->burst_tmr < 0) {
+			ret = phy_read_mmd(phydev, MDIO_MMD_OATC14,
+					   MDIO_OATC14_PLCA_BURST);
+
+			if (ret < 0)
+				return ret;
+
+			val = ret;
+		}
+
+		if (plca_cfg->burst_cnt >= 0)
+			val = (val & ~MDIO_OATC14_PLCA_MAXBC) |
+			      (plca_cfg->burst_cnt << 8);
+
+		if (plca_cfg->burst_tmr >= 0)
+			val = (val & ~MDIO_OATC14_PLCA_BTMR) |
+			      (plca_cfg->burst_tmr);
+
+		ret = phy_write_mmd(phydev, MDIO_MMD_OATC14,
+				    MDIO_OATC14_PLCA_BURST, val);
+
+		if (ret < 0)
+			return ret;
+	}
+
+	// if we need to enable PLCA, do it at the end
+	if (plca_cfg->enabled > 0) {
+		ret = phy_set_bits_mmd(phydev, MDIO_MMD_OATC14,
+				       MDIO_OATC14_PLCA_CTRL0,
+				       MDIO_OATC14_PLCA_EN);
+
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_set_cfg);
+
+/**
+ * genphy_c45_plca_get_status - get PLCA status from standard registers
+ * @phydev: target phy_device struct
+ * @plca_st: output structure to store the PLCA status
+ *
+ * Description: if the PHY complies to the Open Alliance TC14 10BASE-T1S PLCA
+ *   Management Registers specifications, this function can be used to retrieve
+ *   the current PLCA status information from the standard registers in MMD 31.
+ */
+int genphy_c45_plca_get_status(struct phy_device *phydev,
+			       struct phy_plca_status *plca_st)
+{
+	int ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_OATC14, MDIO_OATC14_PLCA_STATUS);
+	if (ret < 0)
+		return ret;
+
+	plca_st->pst = !!(ret & MDIO_OATC14_PLCA_PST);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(genphy_c45_plca_get_status);
+
 struct phy_driver genphy_c45_driver = {
 	.phy_id         = 0xffffffff,
 	.phy_id_mask    = 0xffffffff,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 49d0488bf480..4548c8e8f6a9 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1745,6 +1745,12 @@ int genphy_c45_loopback(struct phy_device *phydev, bool enable);
 int genphy_c45_pma_resume(struct phy_device *phydev);
 int genphy_c45_pma_suspend(struct phy_device *phydev);
 int genphy_c45_fast_retrain(struct phy_device *phydev, bool enable);
+int genphy_c45_plca_get_cfg(struct phy_device *phydev,
+			    struct phy_plca_cfg *plca_cfg);
+int genphy_c45_plca_set_cfg(struct phy_device *phydev,
+			    const struct phy_plca_cfg *plca_cfg);
+int genphy_c45_plca_get_status(struct phy_device *phydev,
+			       struct phy_plca_status *plca_st);
 
 /* Generic C45 PHY driver */
 extern struct phy_driver genphy_c45_driver;
-- 
2.35.1

Re: [PATCH v3 net-next 1/4] net/ethtool: add netlink interface for the PLCA RS

[Russell King (Oracle)]

On Mon, Dec 05, 2022 at 06:17:37PM +0100, Piergiorgio Beruto wrote:
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index e5b6cb1a77f9..99e3497b6aa1 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -543,6 +543,40 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
>  }
>  EXPORT_SYMBOL(phy_ethtool_get_stats);
>  
> +/**
> + *
> + */
> +int phy_ethtool_get_plca_cfg(struct phy_device *dev,
> +			     struct phy_plca_cfg *plca_cfg)
> +{
> +	// TODO
> +	return 0;
> +}
> +EXPORT_SYMBOL(phy_ethtool_get_plca_cfg);
> +
> +/**
> + *
> + */
> +int phy_ethtool_set_plca_cfg(struct phy_device *dev,
> +			     struct netlink_ext_ack *extack,
> +			     const struct phy_plca_cfg *plca_cfg)
> +{
> +	// TODO
> +	return 0;
> +}
> +EXPORT_SYMBOL(phy_ethtool_set_plca_cfg);
> +
> +/**
> + *
> + */
> +int phy_ethtool_get_plca_status(struct phy_device *dev,
> +				struct phy_plca_status *plca_st)
> +{
> +	// TODO
> +	return 0;
> +}
> +EXPORT_SYMBOL(phy_ethtool_get_plca_status);
> +
>  /**
>   * phy_start_cable_test - Start a cable test
>   *
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 716870a4499c..f248010c403d 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -3262,6 +3262,9 @@ static const struct ethtool_phy_ops phy_ethtool_phy_ops = {
>  	.get_sset_count		= phy_ethtool_get_sset_count,
>  	.get_strings		= phy_ethtool_get_strings,
>  	.get_stats		= phy_ethtool_get_stats,
> +	.get_plca_cfg		= phy_ethtool_get_plca_cfg,
> +	.set_plca_cfg		= phy_ethtool_set_plca_cfg,
> +	.get_plca_status	= phy_ethtool_get_plca_status,
>  	.start_cable_test	= phy_start_cable_test,
>  	.start_cable_test_tdr	= phy_start_cable_test_tdr,
>  };

From what I can see, none of the above changes need to be part of
patch 1 - nothing in the rest of the patch requires these members to be
filled in, since you explicitly test to see whether they are before
calling them.

So, rather than introducing docbook stubs and stub functions that
do nothing, marked with "TODO" comments, just merge these changes
above with patch 3, where you actually populate these functions.

Also, why do they need to be exported to modules? From what I can see,
the only user of these functions is phy_device.c, which is part of
the same module as phy.c where the functions live, meaning that they
don't need to be exported.

It's also surely wrong to introduce stubs that return success but
do nothing.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH v3 net-next 1/4] net/ethtool: add netlink interface for the PLCA RS

[Piergiorgio Beruto]

On Mon, Dec 05, 2022 at 06:05:07PM +0000, Russell King (Oracle) wrote:
> On Mon, Dec 05, 2022 at 06:17:37PM +0100, Piergiorgio Beruto wrote:
> > diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> > index e5b6cb1a77f9..99e3497b6aa1 100644
> > --- a/drivers/net/phy/phy.c
> > +++ b/drivers/net/phy/phy.c
> > @@ -543,6 +543,40 @@ int phy_ethtool_get_stats(struct phy_device *phydev,
> >  }
> >  EXPORT_SYMBOL(phy_ethtool_get_stats);
> >  
> > +/**
> > + *
> > + */
> > +int phy_ethtool_get_plca_cfg(struct phy_device *dev,
> > +			     struct phy_plca_cfg *plca_cfg)
> > +{
> > +	// TODO
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(phy_ethtool_get_plca_cfg);
> > +
> > +/**
> > + *
> > + */
> > +int phy_ethtool_set_plca_cfg(struct phy_device *dev,
> > +			     struct netlink_ext_ack *extack,
> > +			     const struct phy_plca_cfg *plca_cfg)
> > +{
> > +	// TODO
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(phy_ethtool_set_plca_cfg);
> > +
> > +/**
> > + *
> > + */
> > +int phy_ethtool_get_plca_status(struct phy_device *dev,
> > +				struct phy_plca_status *plca_st)
> > +{
> > +	// TODO
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(phy_ethtool_get_plca_status);
> > +
> >  /**
> >   * phy_start_cable_test - Start a cable test
> >   *
> > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> > index 716870a4499c..f248010c403d 100644
> > --- a/drivers/net/phy/phy_device.c
> > +++ b/drivers/net/phy/phy_device.c
> > @@ -3262,6 +3262,9 @@ static const struct ethtool_phy_ops phy_ethtool_phy_ops = {
> >  	.get_sset_count		= phy_ethtool_get_sset_count,
> >  	.get_strings		= phy_ethtool_get_strings,
> >  	.get_stats		= phy_ethtool_get_stats,
> > +	.get_plca_cfg		= phy_ethtool_get_plca_cfg,
> > +	.set_plca_cfg		= phy_ethtool_set_plca_cfg,
> > +	.get_plca_status	= phy_ethtool_get_plca_status,
> >  	.start_cable_test	= phy_start_cable_test,
> >  	.start_cable_test_tdr	= phy_start_cable_test_tdr,
> >  };
> 
> From what I can see, none of the above changes need to be part of
> patch 1 - nothing in the rest of the patch requires these members to be
> filled in, since you explicitly test to see whether they are before
> calling them.
My apologies, in my understanding of this process (which is new to me)
the idea of dividing the patches into smaller parts is to facilitate the
review. It was not clear to me that the single patches had to be
self-consistent also from a formal perspective. I was assuming that a
patchset can be accepted or rejected as a whole. Is this the case, or
can you accept only a subset of patches in a set?

In short, I did this because I -thought- it would help the reader
understanding what the intention of the change would be. If this is not
the case, fair enough, I'll not do this in the future.

> 
> So, rather than introducing docbook stubs and stub functions that
> do nothing, marked with "TODO" comments, just merge these changes
> above with patch 3, where you actually populate these functions.
Clear. Do you want me to regenerate the patches into a v4 or do you
think we can move forward with v3 anyway?

> Also, why do they need to be exported to modules? From what I can see,
> the only user of these functions is phy_device.c, which is part of
> the same module as phy.c where the functions live, meaning that they
> don't need to be exported.
I did this because similar functions in the same file are all exported
to modules (e.g. phy_config_aneg, phy_speed_down, phy_start_cable_test).
Therefore, I assumed the intention was to let modules (maybe out-of-tree
modules?) make use of these functions. If you think we should not do
this, would kindly explain why for example the phy_start_cable_test is
exported? I'm really asking because I'm trying to learn the rationales
behind the architectural choices that I see here.

> 
> It's also surely wrong to introduce stubs that return success but
> do nothing.
No doubt it would be wrong if the patch can be integrated regardless of
the other patches in the same set.

> 
> -- 
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH v3 net-next 1/4] net/ethtool: add netlink interface for the PLCA RS

[Andrew Lunn]

> > Also, why do they need to be exported to modules? From what I can see,
> > the only user of these functions is phy_device.c, which is part of
> > the same module as phy.c where the functions live, meaning that they
> > don't need to be exported.
> I did this because similar functions in the same file are all exported
> to modules (e.g. phy_config_aneg, phy_speed_down, phy_start_cable_test).
> Therefore, I assumed the intention was to let modules (maybe out-of-tree
> modules?) make use of these functions. If you think we should not do
> this, would kindly explain why for example the phy_start_cable_test is
> exported?

phy_start_cable_test probably should not be exported. I probably got
this wrong. At one point, it might of been called directly from
net/ethtool/cabletest.c, but not any more. It is now accessed via
phy_ethtool_phy_ops.

Each kernel module is its own name space. You can only reference
something within a kernel module if it is exported. So you will find
all the helper functions in phy_device.c which are used by PHY drivers
are exported, for example.

You need to watch out for circular dependencies between modules, since
they are loaded sequentially. PHYs are generally leaves, they depend
on phylib and nothing else, so that is simple. The phylib module is
loaded first, and then the PHY drivers.

But there are more complex scenarios. A built in driver cannot
reference a module, that would result in undefined symbols. That is
probably what i got wrong with cable tests. I did all my testing with
it built in. But phylib can be built as a module. But that then
implies the core ethtool code cannot be built in, otherwise you get
undefined reference. So it was reworked to reference phylib via
phy_ethtool_phy_ops.

So as Russell says, if a function is only referenced within a module,
there is no need to export it, so keeping the kernel namespace clean.

      Andrew