Subject: [PATCH net-next 3/5] net: sfp: configure/destroy I2C mdiobus on transceiver plug/unplug

From: Marek Behún <[email-masked]>
Date: Wed, 28 Oct 2020 23:14:25 +0100

Instead of configuring the I2C mdiobus when SFP driver is probed,
configure/destroy the mdiobus when SFP transceiver is plugged/unplugged.

This way we can tell the mdio-i2c code which protocol to use for each
SFP transceiver.

Signed-off-by: Marek Behún <[email-masked]>
Cc: Andrew Lunn <[email-masked]>
Cc: Russell King <[email-masked]>
---
 drivers/net/phy/sfp.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index b1f9fc3a5584..a392d5fc6ab4 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -399,9 +399,6 @@ static int sfp_i2c_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf,
 
 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
 {
-	struct mii_bus *i2c_mii;
-	int ret;
-
 	if (!i2c_check_functionality(i2c, I2C_FUNC_I2C))
 		return -EINVAL;
 
@@ -409,7 +406,15 @@ static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
 	sfp->read = sfp_i2c_read;
 	sfp->write = sfp_i2c_write;
 
-	i2c_mii = mdio_i2c_alloc(sfp->dev, i2c, MDIO_I2C_DEFAULT);
+	return 0;
+}
+
+static int sfp_i2c_mdiobus_configure(struct sfp *sfp, enum mdio_i2c_type type)
+{
+	struct mii_bus *i2c_mii;
+	int ret;
+
+	i2c_mii = mdio_i2c_alloc(sfp->dev, sfp->i2c, type);
 	if (IS_ERR(i2c_mii))
 		return PTR_ERR(i2c_mii);
 
@@ -427,6 +432,12 @@ static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)
 	return 0;
 }
 
+static void sfp_i2c_mdiobus_destroy(struct sfp *sfp)
+{
+	mdiobus_unregister(sfp->i2c_mii);
+	sfp->i2c_mii = NULL;
+}
+
 /* Interface */
 static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len)
 {
@@ -1768,6 +1779,11 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 	else
 		sfp->module_t_start_up = T_START_UP;
 
+	/* Configure mdiobus */
+	ret = sfp_i2c_mdiobus_configure(sfp, MDIO_I2C_DEFAULT);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }
 
@@ -1778,6 +1794,8 @@ static void sfp_sm_mod_remove(struct sfp *sfp)
 
 	sfp_hwmon_remove(sfp);
 
+	sfp_i2c_mdiobus_destroy(sfp);
+
 	memset(&sfp->id, 0, sizeof(sfp->id));
 	sfp->module_power_mW = 0;
 
-- 
2.26.2