[PATCH net-next v5 4/5] net: sfp: create/destroy I2C mdiobus before PHY probe/after PHY release

[Marek Behún]

Instead of configuring the I2C mdiobus when SFP driver is probed,
create/destroy the mdiobus before the PHY is probed for/after it is
released.

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

Signed-off-by: Marek Behún <ka...@kernel.org>
Reviewed-by: Pali Rohár <p...@kernel.org>
Cc: Andrew Lunn <and...@lunn.ch>
Cc: Russell King <rmk+ker...@armlinux.org.uk>
---
 drivers/net/phy/sfp.c | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index fac5407c4b87..d1b655f805ab 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -218,6 +218,7 @@ struct sfp {
        struct i2c_adapter *i2c;
        struct mii_bus *i2c_mii;
        struct sfp_bus *sfp_bus;
+       enum mdio_i2c_proto mdio_protocol;
        struct phy_device *mod_phy;
        const struct sff_data *type;
        size_t i2c_block_size;
@@ -413,9 +414,6 @@ 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;
 
@@ -423,7 +421,15 @@ 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_create(struct sfp *sfp)
+{
+       struct mii_bus *i2c_mii;
+       int ret;
+
+       i2c_mii = mdio_i2c_alloc(sfp->dev, sfp->i2c, sfp->mdio_protocol);
        if (IS_ERR(i2c_mii))
                return PTR_ERR(i2c_mii);
 
@@ -441,6 +447,12 @@ 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)
 {
@@ -1881,6 +1893,8 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
        else
                sfp->module_t_start_up = T_START_UP;
 
+       sfp->mdio_protocol = MDIO_I2C_DEFAULT;
+
        return 0;
 }
 
@@ -2051,6 +2065,8 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int 
event)
                        sfp_module_stop(sfp->sfp_bus);
                if (sfp->mod_phy)
                        sfp_sm_phy_detach(sfp);
+               if (sfp->i2c_mii)
+                       sfp_i2c_mdiobus_destroy(sfp);
                sfp_module_tx_disable(sfp);
                sfp_soft_stop_poll(sfp);
                sfp_sm_next(sfp, SFP_S_DOWN, 0);
@@ -2113,6 +2129,12 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int 
event)
                                     sfp->sm_fault_retries == N_FAULT_INIT);
                } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
        init_done:
+                       /* Create mdiobus and start trying for PHY */
+                       ret = sfp_i2c_mdiobus_create(sfp);
+                       if (ret < 0) {
+                               sfp_sm_next(sfp, SFP_S_FAIL, 0);
+                               break;
+                       }
                        sfp->sm_phy_retries = R_PHY_RETRY;
                        goto phy_probe;
                }
-- 
2.26.2