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Diffstat (limited to 'Documentation/networking/phy.txt')
| -rw-r--r-- | Documentation/networking/phy.txt | 86 |
1 files changed, 58 insertions, 28 deletions
diff --git a/Documentation/networking/phy.txt b/Documentation/networking/phy.txt index 0bc95eab151..3544c98401f 100644 --- a/Documentation/networking/phy.txt +++ b/Documentation/networking/phy.txt @@ -1,7 +1,7 @@ ------- PHY Abstraction Layer -(Updated 2006-11-30) +(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 @@ -96,13 +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 + 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, interface); + 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 @@ -112,7 +113,9 @@ 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. @@ -177,18 +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); @@ -196,11 +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); + 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); @@ -213,12 +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); @@ -269,15 +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 @@ -291,3 +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. + |