From: "Marek Behún" <kabel@kernel•org>
To: netdev@vger•kernel.org
Cc: davem@davemloft•net, "Marek Behún" <kabel@kernel•org>,
"Andrew Lunn" <andrew@lunn•ch>,
"Russell King" <rmk+kernel@armlinux•org.uk>
Subject: [PATCH net-next 1/5] net: phy: mdio-i2c: support I2C MDIO protocol for RollBall SFP modules
Date: Wed, 28 Oct 2020 23:14:23 +0100 [thread overview]
Message-ID: <20201028221427.22968-2-kabel@kernel.org> (raw)
In-Reply-To: <20201028221427.22968-1-kabel@kernel.org>
Some multigig SFPs from RollBall and Hilink do not expose functional
MDIO access to the internal PHY of the SFP via I2C address 0x56
(although there seems to be read-only clause 22 access on this address).
Instead these SFPs PHY can be accessed via I2C via the SFP Enhanced
Digital Diagnostic Interface - I2C address 0x51.
This extends the mdio-i2c driver to support this protocol by adding a
special parameter to mdio_i2c_alloc function via which this RollBall
protocol can be selected.
Signed-off-by: Marek Behún <kabel@kernel•org>
Cc: Andrew Lunn <andrew@lunn•ch>
Cc: Russell King <rmk+kernel@armlinux•org.uk>
---
drivers/net/mdio/mdio-i2c.c | 180 +++++++++++++++++++++++++++++++++-
drivers/net/phy/sfp.c | 2 +-
include/linux/mdio/mdio-i2c.h | 8 +-
3 files changed, 183 insertions(+), 7 deletions(-)
diff --git a/drivers/net/mdio/mdio-i2c.c b/drivers/net/mdio/mdio-i2c.c
index 09200a70b315..1f5d653a4e22 100644
--- a/drivers/net/mdio/mdio-i2c.c
+++ b/drivers/net/mdio/mdio-i2c.c
@@ -3,6 +3,7 @@
* MDIO I2C bridge
*
* Copyright (C) 2015-2016 Russell King
+ * Copyright (C) 2020 Marek Behun
*
* Network PHYs can appear on I2C buses when they are part of SFP module.
* This driver exposes these PHYs to the networking PHY code, allowing
@@ -28,7 +29,7 @@ static unsigned int i2c_mii_phy_addr(int phy_id)
return phy_id + 0x40;
}
-static int i2c_mii_read(struct mii_bus *bus, int phy_id, int reg)
+static int i2c_mii_read_default(struct mii_bus *bus, int phy_id, int reg)
{
struct i2c_adapter *i2c = bus->priv;
struct i2c_msg msgs[2];
@@ -62,7 +63,7 @@ static int i2c_mii_read(struct mii_bus *bus, int phy_id, int reg)
return data[0] << 8 | data[1];
}
-static int i2c_mii_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
+static int i2c_mii_write_default(struct mii_bus *bus, int phy_id, int reg, u16 val)
{
struct i2c_adapter *i2c = bus->priv;
struct i2c_msg msg;
@@ -91,7 +92,167 @@ static int i2c_mii_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
return ret < 0 ? ret : 0;
}
-struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c)
+/* RollBall SFPs do not access internal PHY via I2C address 0x56, but
+ * instead via address 0x51, when SFP page is set to 0x03 and password to
+ * 0xffffffff:
+ *
+ * address size contents description
+ * ------- ---- -------- -----------
+ * 0x80 1 CMD 0x01/0x02/0x04 for write/read/done
+ * 0x81 1 DEV Clause 45 device
+ * 0x82 2 REG Clause 45 register
+ * 0x84 2 VAL Register value
+ */
+#define ROLLBALL_PHY_I2C_ADDR 0x51
+
+#define ROLLBALL_CMD_ADDR 0x80
+#define ROLLBALL_DATA_ADDR 0x81
+
+#define ROLLBALL_CMD_WRITE 0x01
+#define ROLLBALL_CMD_READ 0x02
+#define ROLLBALL_CMD_DONE 0x04
+
+static int i2c_rollball_mii_poll(struct mii_bus *bus, int bus_addr, u8 *buf, size_t len)
+{
+ struct i2c_adapter *i2c = bus->priv;
+ struct i2c_msg msgs[2];
+ u8 buf0[2], *res;
+ int i, ret;
+
+ buf0[0] = ROLLBALL_CMD_ADDR;
+
+ msgs[0].addr = bus_addr;
+ msgs[0].flags = 0;
+ msgs[0].len = 1;
+ msgs[0].buf = &buf0[0];
+
+ res = buf ? buf : &buf0[1];
+
+ msgs[1].addr = bus_addr;
+ msgs[1].flags = I2C_M_RD;
+ msgs[1].len = buf ? len : 1;
+ msgs[1].buf = res;
+
+ /* By experiment it takes up to 70 ms to access a register for these SFPs. Sleep 20ms
+ * between iteratios and try 10 times.
+ */
+ i = 10;
+ do {
+ msleep(20);
+
+ ret = i2c_transfer(i2c, msgs, ARRAY_SIZE(msgs));
+ if (ret < 0)
+ return ret;
+ else if (ret != ARRAY_SIZE(msgs))
+ return -EIO;
+
+ if (*res == ROLLBALL_CMD_DONE)
+ return 0;
+ } while (i-- > 0);
+
+ dev_dbg(&bus->dev, "poll timed out\n");
+
+ return -ETIMEDOUT;
+}
+
+static int i2c_rollball_mii_cmd(struct mii_bus *bus, int bus_addr, u8 cmd, u8 *data, size_t len)
+{
+ struct i2c_adapter *i2c = bus->priv;
+ struct i2c_msg msgs[2];
+ u8 cmdbuf[2];
+ int ret;
+
+ msgs[0].addr = bus_addr;
+ msgs[0].flags = 0;
+ msgs[0].len = len;
+ msgs[0].buf = data;
+
+ cmdbuf[0] = ROLLBALL_CMD_ADDR;
+ cmdbuf[1] = cmd;
+
+ msgs[1].addr = bus_addr;
+ msgs[1].flags = 0;
+ msgs[1].len = sizeof(cmdbuf);
+ msgs[1].buf = cmdbuf;
+
+ ret = i2c_transfer(i2c, msgs, 2);
+ if (ret < 0)
+ return ret;
+
+ return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
+}
+
+static int i2c_mii_read_rollball(struct mii_bus *bus, int phy_id, int reg)
+{
+ u8 buf[4], res[6];
+ int bus_addr, ret;
+ u16 val;
+
+ if (!(reg & MII_ADDR_C45))
+ return -EOPNOTSUPP;
+
+ bus_addr = i2c_mii_phy_addr(phy_id);
+ if (bus_addr != ROLLBALL_PHY_I2C_ADDR)
+ return 0xffff;
+
+ buf[0] = ROLLBALL_DATA_ADDR;
+ buf[1] = (reg >> 16) & 0x1f;
+ buf[2] = (reg >> 8) & 0xff;
+ buf[3] = reg & 0xff;
+
+ ret = i2c_rollball_mii_cmd(bus, bus_addr, ROLLBALL_CMD_READ, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_rollball_mii_poll(bus, bus_addr, res, sizeof(res));
+ if (ret == -ETIMEDOUT)
+ return 0xffff;
+ else if (ret < 0)
+ return ret;
+
+ val = res[4];
+ val <<= 8;
+ val |= res[5];
+
+ dev_dbg(&bus->dev, "read reg %02x:%04x = %04x\n", (reg >> 16) & 0x1f, reg & 0xffff, val);
+
+ return val;
+}
+
+static int i2c_mii_write_rollball(struct mii_bus *bus, int phy_id, int reg, u16 val)
+{
+ int bus_addr, ret;
+ u8 buf[6];
+
+ if (!(reg & MII_ADDR_C45))
+ return -EOPNOTSUPP;
+
+ bus_addr = i2c_mii_phy_addr(phy_id);
+ if (bus_addr != ROLLBALL_PHY_I2C_ADDR)
+ return 0;
+
+ buf[0] = ROLLBALL_DATA_ADDR;
+ buf[1] = (reg >> 16) & 0x1f;
+ buf[2] = (reg >> 8) & 0xff;
+ buf[3] = reg & 0xff;
+ buf[4] = val >> 8;
+ buf[5] = val & 0xff;
+
+ ret = i2c_rollball_mii_cmd(bus, bus_addr, ROLLBALL_CMD_WRITE, buf, sizeof(buf));
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_rollball_mii_poll(bus, bus_addr, NULL, 0);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(&bus->dev, "write reg %02x:%04x = %04x\n", (reg >> 16) & 0x1f, reg & 0xffff, val);
+
+ return 0;
+}
+
+struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c,
+ enum mdio_i2c_type type)
{
struct mii_bus *mii;
@@ -104,10 +265,19 @@ struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c)
snprintf(mii->id, MII_BUS_ID_SIZE, "i2c:%s", dev_name(parent));
mii->parent = parent;
- mii->read = i2c_mii_read;
- mii->write = i2c_mii_write;
mii->priv = i2c;
+ switch (type) {
+ case MDIO_I2C_ROLLBALL:
+ mii->read = i2c_mii_read_rollball;
+ mii->write = i2c_mii_write_rollball;
+ break;
+ default:
+ mii->read = i2c_mii_read_default;
+ mii->write = i2c_mii_write_default;
+ break;
+ }
+
return mii;
}
EXPORT_SYMBOL_GPL(mdio_i2c_alloc);
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 1d18c10e8f82..b1f9fc3a5584 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -409,7 +409,7 @@ 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);
+ i2c_mii = mdio_i2c_alloc(sfp->dev, i2c, MDIO_I2C_DEFAULT);
if (IS_ERR(i2c_mii))
return PTR_ERR(i2c_mii);
diff --git a/include/linux/mdio/mdio-i2c.h b/include/linux/mdio/mdio-i2c.h
index b1d27f7cd23f..b65a80938806 100644
--- a/include/linux/mdio/mdio-i2c.h
+++ b/include/linux/mdio/mdio-i2c.h
@@ -11,6 +11,12 @@ struct device;
struct i2c_adapter;
struct mii_bus;
-struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c);
+enum mdio_i2c_type {
+ MDIO_I2C_DEFAULT,
+ MDIO_I2C_ROLLBALL,
+};
+
+struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c,
+ enum mdio_i2c_type type);
#endif
--
2.26.2
next prev parent reply other threads:[~2020-10-28 22:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-28 22:14 [PATCH net-next 0/5] Support for RollBall 10G copper SFP modules Marek Behún
2020-10-28 22:14 ` Marek Behún [this message]
2020-10-29 12:41 ` [PATCH net-next 1/5] net: phy: mdio-i2c: support I2C MDIO protocol for RollBall " Russell King - ARM Linux admin
2020-10-29 12:54 ` Andrew Lunn
2020-10-29 13:41 ` Russell King - ARM Linux admin
2020-10-29 22:53 ` Jakub Kicinski
2020-10-29 22:55 ` Marek Behún
2020-10-29 16:46 ` Marek Behún
2020-10-28 22:14 ` [PATCH net-next 2/5] net: phylink: allow attaching phy for SFP modules on 802.3z mode Marek Behún
2020-10-29 12:08 ` Russell King - ARM Linux admin
2020-10-28 22:14 ` [PATCH net-next 3/5] net: sfp: configure/destroy I2C mdiobus on transceiver plug/unplug Marek Behún
2020-10-29 13:21 ` Russell King - ARM Linux admin
2020-10-28 22:14 ` [PATCH net-next 4/5] net: phy: marvell10g: change MACTYPE if underlying MAC does not support it Marek Behún
2020-10-29 13:21 ` Russell King - ARM Linux admin
2020-10-28 22:14 ` [PATCH net-next 5/5] net: sfp: add support for multigig RollBall transceivers Marek Behún
2020-10-29 13:38 ` Russell King - ARM Linux admin
2020-10-29 16:49 ` Marek Behún
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