| Message ID | 20201028221427.22968-2-kabel@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Support for RollBall 10G copper SFP modules | expand |
On Wed, Oct 28, 2020 at 11:14:23PM +0100, Marek Behún wrote: > 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> I think this is probably a better way forward, and I suspect we're going to see more of this stuff. I wonder, however, whether the configuration should be done here too (selecting page 1). Also, shouldn't we ensure that we are on page 1 before attempting any access? It would be good to pass this through checkpatch - I notice some lines seem to be over the 80 character limit now. A few comments below... > +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. "iterations" > +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]; Was there something wrong with: val = res[4] << 8 | res[5]; here? > +struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c, > + enum mdio_i2c_type type) Maybe call this "protocol" rather than "type" ? > +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); Same here (protocol vs type). Otherwise, I don't see much else wrong.
> It would be good to pass this through checkpatch - I notice some lines > seem to be over the 80 character limit now. Hi Russell The limit got raised to something higher. I personally prefer 80, and if a file is using 80, new code would be inconsistent with old code if it did not use 80. So your request is reasonable anyway. Andrew
On Thu, Oct 29, 2020 at 01:54:39PM +0100, Andrew Lunn wrote: > > It would be good to pass this through checkpatch - I notice some lines > > seem to be over the 80 character limit now. > > Hi Russell > > The limit got raised to something higher. I personally prefer 80, and > if a file is using 80, new code would be inconsistent with old code if > it did not use 80. So your request is reasonable anyway. Hi Andrew, I do most of my kernel hacking on the Linux console, so 80x25 is the limit of what I see - and depending on the editor I'm using, lines longer than 80 characters are chopped to 80 characters unless I scroll to the right (which then makes moving up and down problematical.) So, the files I'm responsible for are likely to stay requiring an 80 character width.
On Thu, 29 Oct 2020 12:41:41 +0000 Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote: > I think this is probably a better way forward, and I suspect we're going > to see more of this stuff. I wonder, however, whether the configuration > should be done here too (selecting page 1). Also, shouldn't we ensure > that we are on page 1 before attempting any access? Very well. > It would be good to pass this through checkpatch - I notice some lines > seem to be over the 80 character limit now. Checkpatch does not complain at over 80 characters anymore, but over 100. But I will rewrite it. > "iterations" /o\ thx > > + val = res[4]; > > + val <<= 8; > > + val |= res[5]; > > Was there something wrong with: > > val = res[4] << 8 | res[5]; > > here? For some reason I preferred to use the 3-liner, but I shall rewrite it. > > > +struct mii_bus *mdio_i2c_alloc(struct device *parent, struct i2c_adapter *i2c, > > + enum mdio_i2c_type type) > > Maybe call this "protocol" rather than "type" ? Very well, thx
On Thu, 29 Oct 2020 13:41:07 +0000 Russell King - ARM Linux admin wrote: > On Thu, Oct 29, 2020 at 01:54:39PM +0100, Andrew Lunn wrote: > > > It would be good to pass this through checkpatch - I notice some lines > > > seem to be over the 80 character limit now. > > > > Hi Russell > > > > The limit got raised to something higher. I personally prefer 80, and > > if a file is using 80, new code would be inconsistent with old code if > > it did not use 80. So your request is reasonable anyway. > > Hi Andrew, > > I do most of my kernel hacking on the Linux console, so 80x25 is the > limit of what I see - and depending on the editor I'm using, lines > longer than 80 characters are chopped to 80 characters unless I scroll > to the right (which then makes moving up and down problematical.) So, > the files I'm responsible for are likely to stay requiring an 80 > character width. +1 Maybe we should patch checkpatch to still enforce 80 for networking.
On Thu, 29 Oct 2020 15:53:48 -0700 Jakub Kicinski <kuba@kernel.org> wrote: > +1 > > Maybe we should patch checkpatch to still enforce 80 for networking. If you do, do that for leds as well, Pavel will be glad.
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
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(-)