UTOPIA(9)

NAME
utopia - driver module for ATM PHY chips

SYNOPSIS
#include <dev/utopia/utopia.h>
int
utopia_attach(struct utopia *utp, struct ifatm *ifatm, struct ifmedia *media, struct mtx *lock, struct sysctl_ctx_list *ctx, struct sysctl_oid_list *tree, const struct utopia_methods *vtab);
void
utopia_detach(struct utopia *utp);
int
utopia_start(struct utopia *utp);
void
utopia_stop(struct utopia *utp);
void
utopia_init_media(struct utopia *utp);
void
utopia_reset_media(struct utopia *utp);
int
utopia_reset(struct utopia *utp);
int
utopia_set_sdh(struct utopia *utp, int sdh);
int
utopia_set_unass(struct utopia *utp, int unass);
int
utopia_set_noscramb(struct utopia *utp, int noscramb);
int
utopia_update_carrier(struct utopia *utp);
int
utopia_set_loopback(struct utopia *utp, u_int mode);
void
utopia_intr(struct utopia *utp);
void
utopia_update_stats(struct utopia *utp);

DESCRIPTION
This module is used by all ATM drivers for cards that use a number of known PHY chips to provide uniform functionality. The module implements status monitoring in either interrupt or polling mode, media option handling and application access to PHY registers.

To use this interface, a driver must implement two functions for reading and writing PHY registers, and initialize the following structure with pointers to these functions:

    struct utopia_methods {
    	int	(*readregs)(struct ifatm *, u_int reg,
    		    uint8_t *val, u_int *n);
    	int	(*writereg)(struct ifatm *, u_int reg,
    		    u_int mask, u_int val);
    };

The readregs() function should read PHY registers starting at register reg. The maximum number of registers to read is given by the integer pointed to by n. The function should either return 0 on success, or an error code. In the first case, *n should be set to the actual number of registers read. The writereg() function should write one register. It must change all bits for which the corresponding bit in mask is 1 to the value of the corresponding bit in val. It returns either 0 on success, or an error code.

The ATM driver's private state block (softc) must begin with a struct ifatm.

The struct utopia holds the current state of the PHY chip and contains the following fields:

    struct utopia {
    	struct ifatm	*ifatm;		/* driver data */
    	struct ifmedia	*media;		/* driver supplied */
    	struct mtx	*lock;		/* driver supplied */
    	const struct utopia_methods *methods;
    	LIST_ENTRY(utopia) link;	/* list of these structures */
    	u_int		flags;		/* flags set by the driver */
    	u_int		state;		/* current state */
    	u_int		carrier;	/* carrier state */
    	u_int		loopback;	/* loopback mode */
    	const struct utopia_chip *chip;	/* chip operations */
    	struct utopia_stats1 stats;	/* statistics */
    };

The public accessible fields have the following functions:

ifatm
    Pointer to the driver's private data (softc).

media
    Pointer to the driver's media structure.

lock
    Pointer to a mutex provided by the driver. This mutex is used to synchronize with the kernel thread that handles device polling. It is locked in several places:

    1.  In utopia_detach() the mutex is locked to sleep and wait for the kernel thread to remove the struct utopia from the list of all utopia devices. Before returning to the caller the mutex is unlocked.

    2.  In the utopia kernel thread the mutex is locked, and the utopia_carrier_update() function is called with this mutex locked. This will result in the driver's readregs() function being called with the mutex locked.

    3.  In the sysctl handlers the mutex will be locked before calling into the driver's readreg() or writereg() functions.

flags
    Flags set by either the driver or the utopia module. The following flags are defined:

    UTP_FL_NORESET
        If this flag is set, the module will not try to write the SUNI master reset register. (Set by the driver.)

    UTP_FL_POLL_CARRIER
        If this flag is set, the module will periodically poll the carrier state (as opposed to interrupt driven carrier state changes). (Set by the driver.)

state
    Flags describing the current state of the PHY chip. These are managed by the module:

    UTP_ST_ACTIVE
        The driver is active and the PHY registers can be accessed. This is set by calling utopia_start(), which should be called either in the attach routine of the driver or in the network interface initialisation routine (depending on whether the registers are accessible all the time or only when the interface is up).

    UTP_ST_SDH
        Interface is in SDH mode as opposed to SONET mode.

    UTP_ST_UNASS
        Interface is producing unassigned cells instead of idle cells.

    UTP_ST_NOSCRAMB
        Cell scrambling is switched off.

    UTP_ST_DETACH
        (Internal use.) Interface is currently detaching.

    UTP_ST_ATTACHED
        The attach routine has been run successfully.

carrier
    The carrier state of the interface. This field can have one of three values:

    UTP_CARR_UNKNOWN
        Carrier state is still unknown.

    UTP_CARR_OK
        Carrier has been detected.

    UTP_CARR_LOST
        Carrier has been lost.

loopback
    This is the current loopback mode of the interface. Note that not all chips support all loopback modes. Refer to the chip documentation. The following modes may be supported:

    UTP_LOOP_NONE
        No loopback, normal operation.

    UTP_LOOP_TIME
        Timing source loopback. The transmitter clock is driven by the receive clock.

    UTP_LOOP_DIAG
        Diagnostic loopback.

    UTP_LOOP_LINE
        Serial line loopback.

    UTP_LOOP_PARAL
        Parallel diagnostic loopback.

    UTP_LOOP_TWIST
        Twisted pair diagnostic loopback.

    UTP_LOOP_PATH
        Diagnostic path loopback.

chip
    This points to a function vector for chip specific functions. Two fields in this vector are publicly available:

    type
        This is the type of the detected PHY chip. One of:

        UTP_TYPE_UNKNOWN (0)
        UTP_TYPE_SUNI_LITE (1)
        UTP_TYPE_SUNI_ULTRA (2)
        UTP_TYPE_SUNI_622 (3)
        UTP_TYPE_IDT77105 (4)

    name
        This is a string with the name of the PHY chip.

The following functions are used by the driver during attach/detach and/or initialisation/stopping the interface:

utopia_attach()
    Attach the PHY chip. This is called with a preallocated struct utopia (which may be part of the driver's softc). The module initializes all fields of the utopia state and the media field. User settable flags should be set after the call to utopia_attach(). This function may fail due to the inability to install the sysctl handlers. In this case it will return -1. On success, 0 is returned and the UTP_ST_ATTACHED flag is set.

utopia_detach()
    Remove the utopia attachment from the system. This cancels all outstanding polling timeouts.

utopia_start()
    Start operation of that PHY. This should be called at a time when the PHY registers are known to be accessible. This may be either in the driver's attach function or when the interface is set running.

utopia_stop()
    Stop operation of the PHY attachment. This may be called either in the detach function of the driver or when the interface is brought down.

utopia_init_media()
    This must be called if the media field in the ATM MIB was changed. The function makes sure, that the ifmedia fields contain the same information as the ATM MIB.

utopia_reset_media()
    This may be called to remove all media information from the ifmedia field.

The following functions can be used to modify the PHY state while the interface is running:

utopia_reset()
    Reset the operational parameters to the default state (SONET, idle cells, scrambling enabled). Returns 0 on success, an error code otherwise, leaving the state undefined.

utopia_set_sdh()
    If the argument is zero the chip is switched to Sonet mode, if it is non-zero the chip is switched to SDH mode. Returns 0 on success, an error code otherwise, leaving the previous state.

utopia_set_unass()
    If the argument is zero the chip is switched to produce idle cells, if it is non-zero the chip is switched to produce unassigned cells. Returns 0 on success, an error code otherwise, leaving the previous state.

utopia_set_noscramb()
    If the argument is zero enables scrambling, if it is non-zero disables scrambling. Returns 0 on success, an error code otherwise, leaving the previous state.

utopia_update_carrier()
    Check the carrier state and update the carrier field in the state structure. This will generate a message to the Netgraph stack if the carrier state changes. For chips that are polled this is called automatically, for interrupt driven attachments this must be called on interrupts from the PHY chip.

utopia_set_loopback()
    Set the loopback mode of the chip. Returns 0 on success, an error code otherwise, leaving the previous state.

utopia_intr()
    Called when an interrupt from the PHY chip is detected. This resets the interrupt state by reading all registers and, if the interrupt was from the RSOP, checks the carrier state.

utopia_update_stats()
    Update the statistics with counters read from the chip.

SEE ALSO
utopia(4)

AUTHORS
Harti Brandt <harti@FreeBSD.org>