[PATCH net-next 12/16] net: pcs: xpcs: Add xpcs_create_bynode() method

[Serge Semin <fancer.lancer@gmail.com>]

It's now possible to have the DW XPCS device defined as a standard
platform device for instance in the platform DT-file. Although it's
pointless unless there is a way to have the device found by the client
drivers (STMMAC/DW *MAC, NXP SJA1105 Eth Switch, etc). Provide such
ability by means of the xpcs_create_bynode() method. It needs to be
supplied with the device fwnode which is equipped with the "pcs-handle"
property pointing to the DW XPCS fw-node (in this regards it looks similar
to the phylink interface). That node will be then used to find the
MDIO-device instance in order to create the DW XPCS descriptor.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
 drivers/net/pcs/pcs-xpcs.c   | 26 ++++++++++++++++++++++++++
 include/linux/pcs/pcs-xpcs.h |  3 +++
 2 files changed, 29 insertions(+)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index e376e255f1d3..c3336895a124 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -9,9 +9,11 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/fwnode.h>
 #include <linux/mdio.h>
 #include <linux/module.h>
 #include <linux/pcs/pcs-xpcs.h>
+#include <linux/phy.h>
 #include <linux/phylink.h>
 #include <linux/property.h>
 
@@ -1511,6 +1513,30 @@ static struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
 	return ERR_PTR(ret);
 }
 
+struct dw_xpcs *xpcs_create_bynode(const struct fwnode_handle *fwnode,
+				   phy_interface_t interface)
+{
+	struct fwnode_handle *pcs_node;
+	struct mdio_device *mdiodev;
+	struct dw_xpcs *xpcs;
+
+	pcs_node = fwnode_find_reference(fwnode, "pcs-handle", 0);
+	if (IS_ERR(pcs_node))
+		return ERR_CAST(pcs_node);
+
+	mdiodev = fwnode_mdio_find_device(pcs_node);
+	fwnode_handle_put(pcs_node);
+	if (!mdiodev)
+		return ERR_PTR(-ENODEV);
+
+	xpcs = xpcs_create(mdiodev, interface);
+	if (IS_ERR(xpcs))
+		mdio_device_put(mdiodev);
+
+	return xpcs;
+}
+EXPORT_SYMBOL_GPL(xpcs_create_bynode);
+
 struct dw_xpcs *xpcs_create_byaddr(struct mii_bus *bus, int addr,
 				   phy_interface_t interface)
 {
diff --git a/include/linux/pcs/pcs-xpcs.h b/include/linux/pcs/pcs-xpcs.h
index b11bbb5e820a..2981dcdf65d4 100644
--- a/include/linux/pcs/pcs-xpcs.h
+++ b/include/linux/pcs/pcs-xpcs.h
@@ -8,6 +8,7 @@
 #define __LINUX_PCS_XPCS_H
 
 #include <linux/clk.h>
+#include <linux/fwnode.h>
 #include <linux/mdio.h>
 #include <linux/phy.h>
 #include <linux/phylink.h>
@@ -73,6 +74,8 @@ int xpcs_do_config(struct dw_xpcs *xpcs, phy_interface_t interface,
 void xpcs_get_interfaces(struct dw_xpcs *xpcs, unsigned long *interfaces);
 int xpcs_config_eee(struct dw_xpcs *xpcs, int mult_fact_100ns,
 		    int enable);
+struct dw_xpcs *xpcs_create_bynode(const struct fwnode_handle *fwnode,
+				   phy_interface_t interface);
 struct dw_xpcs *xpcs_create_byaddr(struct mii_bus *bus, int addr,
 				   phy_interface_t interface);
 void xpcs_destroy(struct dw_xpcs *xpcs);
-- 
2.42.1