[PATCH net-next 07/16] net: pcs: xpcs: Split up xpcs_create() content to sub-functions

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

As a final preparation before adding the DW XPCS MDIO-device driver
support let's split the xpcs_create() function code up to a set of small
sub-functions. Thus the method implementation will get to look simpler and
turn to be more coherent. Further updates will just touch the new methods
a bit: add platform-specific device info, add device reference clock
getting and enabling.

This update implies the xpcs_create() to call the next static methods:
xpcs_create_data() - create the DW XPCS device descriptor,
xpcs_init_id() - find XPCS ID instance and save it in the device
descriptor,
xpcs_init_iface() - find MAC/PCS interface descriptor and perform
basice initialization specific to it: soft-reset, disable polling.

The update doesn't cause any semantic change but merely makes the code
better looking and ready for adding new features support.

Note in addition to that the xpcs_destroy() is moved to be below the
xpcs_create_mdiodev() function as the driver now implies having the
protagonist-then-antagonist functions definition order.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
 drivers/net/pcs/pcs-xpcs.c | 102 +++++++++++++++++++++++++------------
 1 file changed, 70 insertions(+), 32 deletions(-)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index a53376472394..ea6f56339595 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -1365,70 +1365,97 @@ static const struct phylink_pcs_ops xpcs_phylink_ops = {
 	.pcs_link_up = xpcs_link_up,
 };
 
-static struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
-				   phy_interface_t interface)
+static struct dw_xpcs *xpcs_create_data(struct mdio_device *mdiodev)
 {
 	struct dw_xpcs *xpcs;
-	u32 xpcs_id;
-	int i, ret;
 
 	xpcs = kzalloc(sizeof(*xpcs), GFP_KERNEL);
 	if (!xpcs)
 		return ERR_PTR(-ENOMEM);
 
 	xpcs->mdiodev = mdiodev;
+	xpcs->pcs.ops = &xpcs_phylink_ops;
+	xpcs->pcs.neg_mode = true;
+	xpcs->pcs.poll = true;
+
+	return xpcs;
+}
+
+static void xpcs_free_data(struct dw_xpcs *xpcs)
+{
+	kfree(xpcs);
+}
+
+static int xpcs_init_id(struct dw_xpcs *xpcs)
+{
+	u32 xpcs_id;
+	int i, ret;
 
 	xpcs_id = xpcs_get_id(xpcs);
 
 	for (i = 0; i < ARRAY_SIZE(xpcs_id_list); i++) {
 		const struct xpcs_id *entry = &xpcs_id_list[i];
-		const struct xpcs_compat *compat;
 
 		if ((xpcs_id & entry->mask) != entry->id)
 			continue;
 
 		xpcs->id = entry;
 
-		compat = xpcs_find_compat(entry, interface);
-		if (!compat) {
-			ret = -ENODEV;
-			goto out;
-		}
+		break;
+	}
 
-		ret = xpcs_dev_flag(xpcs);
-		if (ret)
-			goto out;
+	if (!xpcs->id)
+		return -ENODEV;
 
-		xpcs->pcs.ops = &xpcs_phylink_ops;
-		xpcs->pcs.neg_mode = true;
+	ret = xpcs_dev_flag(xpcs);
+	if (ret < 0)
+		return ret;
 
-		if (xpcs->dev_flag != DW_DEV_TXGBE) {
-			xpcs->pcs.poll = true;
+	return 0;
+}
 
-			ret = xpcs_soft_reset(xpcs, compat);
-			if (ret)
-				goto out;
-		}
+static int xpcs_init_iface(struct dw_xpcs *xpcs, phy_interface_t interface)
+{
+	const struct xpcs_compat *compat;
 
-		return xpcs;
+	compat = xpcs_find_compat(xpcs->id, interface);
+	if (!compat)
+		return -EINVAL;
+
+	if (xpcs->dev_flag == DW_DEV_TXGBE) {
+		xpcs->pcs.poll = false;
+		return 0;
 	}
 
-	ret = -ENODEV;
+	return xpcs_soft_reset(xpcs, compat);
+}
+
+static struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
+				   phy_interface_t interface)
+{
+	struct dw_xpcs *xpcs;
+	int ret;
+
+	xpcs = xpcs_create_data(mdiodev);
+	if (IS_ERR(xpcs))
+		return xpcs;
+
+	ret = xpcs_init_id(xpcs);
+	if (ret)
+		goto out;
+
+	ret = xpcs_init_iface(xpcs, interface);
+	if (ret)
+		goto out;
+
+	return xpcs;
 
 out:
-	kfree(xpcs);
+	xpcs_free_data(xpcs);
 
 	return ERR_PTR(ret);
 }
 
-void xpcs_destroy(struct dw_xpcs *xpcs)
-{
-	if (xpcs)
-		mdio_device_put(xpcs->mdiodev);
-	kfree(xpcs);
-}
-EXPORT_SYMBOL_GPL(xpcs_destroy);
-
 struct dw_xpcs *xpcs_create_mdiodev(struct mii_bus *bus, int addr,
 				    phy_interface_t interface)
 {
@@ -1455,4 +1482,15 @@ struct dw_xpcs *xpcs_create_mdiodev(struct mii_bus *bus, int addr,
 }
 EXPORT_SYMBOL_GPL(xpcs_create_mdiodev);
 
+void xpcs_destroy(struct dw_xpcs *xpcs)
+{
+	if (!xpcs)
+		return;
+
+	mdio_device_put(xpcs->mdiodev);
+
+	xpcs_free_data(xpcs);
+}
+EXPORT_SYMBOL_GPL(xpcs_destroy);
+
 MODULE_LICENSE("GPL v2");
-- 
2.42.1