From 922f2dd1b65a888e34c472979460dc23211750a2 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 12 May 2015 10:33:24 -0700 Subject: net: phy: Add phy_ignore_ta_mask to account for broken turn-around Some PHY devices/switches will not release the turn-around line as they should do at the end of a MDIO transaction. To help with such situations, allow MDIO bus drivers to be made aware of such restrictions. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- include/linux/phy.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/phy.h b/include/linux/phy.h index 685809835b5c..701c7a3946e0 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -181,6 +181,9 @@ struct mii_bus { /* PHY addresses to be ignored when probing */ u32 phy_mask; + /* PHY addresses to ignore the TA/read failure */ + u32 phy_ignore_ta_mask; + /* * Pointer to an array of interrupts, each PHY's * interrupt at the index matching its address -- cgit v1.2.3 From ab6016e0c134c3a564e6750f5b246ba17ada4686 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 12 May 2015 10:33:25 -0700 Subject: of: mdio: Add a "broken-turn-around" property Some Ethernet PHY devices/switches may not properly release the MDIO bus during turn-around time, and fail to drive it low, which can be seen by some controllers as a read failure, while the data clocked in is still correct. Add a boolean property "broken-turn-around" which is parsed by the generic MDIO bus probing code and will set the corresponding bit in the MDIO bus phy_ignore_ta_mask bitmask for MDIO bus drivers to utilize that information. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- Documentation/devicetree/bindings/net/phy.txt | 3 +++ drivers/of/of_mdio.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/net/phy.txt b/Documentation/devicetree/bindings/net/phy.txt index 40831fbaff72..525e1658f2da 100644 --- a/Documentation/devicetree/bindings/net/phy.txt +++ b/Documentation/devicetree/bindings/net/phy.txt @@ -30,6 +30,9 @@ Optional Properties: - max-speed: Maximum PHY supported speed (10, 100, 1000...) +- broken-turn-around: If set, indicates the PHY device does not correctly + release the turn around line low at the end of a MDIO transaction. + Example: ethernet-phy@0 { diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index 0c064485d1c2..fdc60db60829 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -68,6 +68,9 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *chi phy->irq = mdio->irq[addr]; } + if (of_property_read_bool(child, "broken-turn-around")) + mdio->phy_ignore_ta_mask |= 1 << addr; + /* Associate the OF node with the device structure so it * can be looked up later */ of_node_get(child); -- cgit v1.2.3 From ea48b2b8ada594e985b86da98b0c966d1ae23a4b Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 12 May 2015 10:33:26 -0700 Subject: net: phy: mdio-gpio: Handle phy_ignore_ta_mask Update mdiobb_read() to read whether the PHY has a broken turn-around, and if it does, ignore it to make the read succeeed. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio-bitbang.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/phy/mdio-bitbang.c b/drivers/net/phy/mdio-bitbang.c index daec9b05d168..61a543c788cc 100644 --- a/drivers/net/phy/mdio-bitbang.c +++ b/drivers/net/phy/mdio-bitbang.c @@ -165,8 +165,11 @@ static int mdiobb_read(struct mii_bus *bus, int phy, int reg) ctrl->ops->set_mdio_dir(ctrl, 0); - /* check the turnaround bit: the PHY should be driving it to zero */ - if (mdiobb_get_bit(ctrl) != 0) { + /* check the turnaround bit: the PHY should be driving it to zero, if this + * PHY is listed in phy_ignore_ta_mask as having broken TA, skip that + */ + if (mdiobb_get_bit(ctrl) != 0 && + !(bus->phy_ignore_ta_mask & (1 << phy))) { /* PHY didn't drive TA low -- flush any bits it * may be trying to send. */ -- cgit v1.2.3