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Diffstat (limited to 'Documentation/networking/phy.txt')
| -rw-r--r-- | Documentation/networking/phy.txt | 93 |
1 files changed, 64 insertions, 29 deletions
diff --git a/Documentation/networking/phy.txt b/Documentation/networking/phy.txt index 29ccae40903..3544c98401f 100644 --- a/Documentation/networking/phy.txt +++ b/Documentation/networking/phy.txt @@ -1,7 +1,7 @@ ------- PHY Abstraction Layer -(Updated 2005-07-21) +(Updated 2008-04-08) Purpose @@ -48,7 +48,7 @@ The MDIO bus time, so it is safe for them to block, waiting for an interrupt to signal the operation is complete - 2) A reset function is necessary. This is used to return the bus to an + 2) A reset function is optional. This is used to return the bus to an initialized state. 3) A probe function is needed. This function should set up anything the bus @@ -62,7 +62,8 @@ The MDIO bus 5) The bus must also be declared somewhere as a device, and registered. As an example for how one driver implemented an mdio bus driver, see - drivers/net/gianfar_mii.c and arch/ppc/syslib/mpc85xx_devices.c + drivers/net/ethernet/freescale/fsl_pq_mdio.c and an associated DTS file + for one of the users. (e.g. "git grep fsl,.*-mdio arch/powerpc/boot/dts/") Connecting to a PHY @@ -96,12 +97,13 @@ Letting the PHY Abstraction Layer do Everything static void adjust_link(struct net_device *dev); Next, you need to know the device name of the PHY connected to this device. - The name will look something like, "phy0:0", where the first number is the - bus id, and the second is the PHY's address on that bus. + The name will look something like, "0:00", where the first number is the + bus id, and the second is the PHY's address on that bus. Typically, + the bus is responsible for making its ID unique. Now, to connect, just call this function: - phydev = phy_connect(dev, phy_name, &adjust_link, flags); + phydev = phy_connect(dev, phy_name, &adjust_link, interface); phydev is a pointer to the phy_device structure which represents the PHY. If phy_connect is successful, it will return the pointer. dev, here, is the @@ -111,10 +113,16 @@ Letting the PHY Abstraction Layer do Everything current state, though the PHY will not yet be truly operational at this point. - flags is a u32 which can optionally contain phy-specific flags. + PHY-specific flags should be set in phydev->dev_flags prior to the call + to phy_connect() such that the underlying PHY driver can check for flags + and perform specific operations based on them. This is useful if the system has put hardware restrictions on the PHY/controller, of which the PHY needs to be aware. + interface is a u32 which specifies the connection type used + between the controller and the PHY. Examples are GMII, MII, + RGMII, and SGMII. For a full list, see include/linux/phy.h + Now just make sure that phydev->supported and phydev->advertising have any values pruned from them which don't make sense for your controller (a 10/100 controller may be connected to a gigabit capable PHY, so you would need to @@ -172,18 +180,6 @@ Doing it all yourself A convenience function to print out the PHY status neatly. - int phy_clear_interrupt(struct phy_device *phydev); - int phy_config_interrupt(struct phy_device *phydev, u32 interrupts); - - Clear the PHY's interrupt, and configure which ones are allowed, - respectively. Currently only supports all on, or all off. - - int phy_enable_interrupts(struct phy_device *phydev); - int phy_disable_interrupts(struct phy_device *phydev); - - Functions which enable/disable PHY interrupts, clearing them - before and after, respectively. - int phy_start_interrupts(struct phy_device *phydev); int phy_stop_interrupts(struct phy_device *phydev); @@ -191,11 +187,10 @@ Doing it all yourself start, or disables then frees them for stop. struct phy_device * phy_attach(struct net_device *dev, const char *phy_id, - u32 flags); + phy_interface_t interface); Attaches a network device to a particular PHY, binding the PHY to a generic - driver if none was found during bus initialization. Passes in - any phy-specific flags as needed. + driver if none was found during bus initialization. int phy_start_aneg(struct phy_device *phydev); @@ -208,12 +203,6 @@ Doing it all yourself Fills the phydev structure with up-to-date information about the current settings in the PHY. - void phy_sanitize_settings(struct phy_device *phydev) - - Resolves differences between currently desired settings, and - supported settings for the given PHY device. Does not make - the changes in the hardware, though. - int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd); int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd); @@ -264,15 +253,25 @@ Writing a PHY driver Each driver consists of a number of function pointers: + soft_reset: perform a PHY software reset config_init: configures PHY into a sane state after a reset. For instance, a Davicom PHY requires descrambling disabled. - probe: Does any setup needed by the driver + probe: Allocate phy->priv, optionally refuse to bind. + PHY may not have been reset or had fixups run yet. suspend/resume: power management config_aneg: Changes the speed/duplex/negotiation settings + aneg_done: Determines the auto-negotiation result read_status: Reads the current speed/duplex/negotiation settings ack_interrupt: Clear a pending interrupt + did_interrupt: Checks if the PHY generated an interrupt config_intr: Enable or disable interrupts remove: Does any driver take-down + ts_info: Queries about the HW timestamping status + hwtstamp: Set the PHY HW timestamping configuration + rxtstamp: Requests a receive timestamp at the PHY level for a 'skb' + txtsamp: Requests a transmit timestamp at the PHY level for a 'skb' + set_wol: Enable Wake-on-LAN at the PHY level + get_wol: Get the Wake-on-LAN status at the PHY level Of these, only config_aneg and read_status are required to be assigned by the driver code. The rest are optional. Also, it is @@ -286,3 +285,39 @@ Writing a PHY driver Feel free to look at the Marvell, Cicada, and Davicom drivers in drivers/net/phy/ for examples (the lxt and qsemi drivers have not been tested as of this writing) + +Board Fixups + + Sometimes the specific interaction between the platform and the PHY requires + special handling. For instance, to change where the PHY's clock input is, + or to add a delay to account for latency issues in the data path. In order + to support such contingencies, the PHY Layer allows platform code to register + fixups to be run when the PHY is brought up (or subsequently reset). + + When the PHY Layer brings up a PHY it checks to see if there are any fixups + registered for it, matching based on UID (contained in the PHY device's phy_id + field) and the bus identifier (contained in phydev->dev.bus_id). Both must + match, however two constants, PHY_ANY_ID and PHY_ANY_UID, are provided as + wildcards for the bus ID and UID, respectively. + + When a match is found, the PHY layer will invoke the run function associated + with the fixup. This function is passed a pointer to the phy_device of + interest. It should therefore only operate on that PHY. + + The platform code can either register the fixup using phy_register_fixup(): + + int phy_register_fixup(const char *phy_id, + u32 phy_uid, u32 phy_uid_mask, + int (*run)(struct phy_device *)); + + Or using one of the two stubs, phy_register_fixup_for_uid() and + phy_register_fixup_for_id(): + + int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask, + int (*run)(struct phy_device *)); + int phy_register_fixup_for_id(const char *phy_id, + int (*run)(struct phy_device *)); + + The stubs set one of the two matching criteria, and set the other one to + match anything. + |