PCKBPORT(9)						   BSD Kernel Developer's Manual					       PCKBPORT(9)

NAME

     pckbport, pckbport_attach, pckbport_attach_slot, pckbport_cnattach, pckbportintr, pckbport_set_inputhandler, pckbport_flush,
     pckbport_poll_cmd, pckbport_enqueue_cmd, pckbport_poll_data, pckbport_set_poll, pckbport_xt_translation, pckbport_slot_enable -- PC keyboard
     port interface

SYNOPSIS

     #include <dev/pckbport/pckbportvar.h>

     pckbport_tag_t
     pckbport_attach(void *, struct pckbport_accessops const *);

     struct device *
     pckbport_attach_slot(struct device *, pckbport_tag_t, pckbport_slot_t);

     int
     pckbport_cnattach(void *, struct pckbport_accessops const *, pckbport_slot_t);

     void
     pckbportintr(pckbport_tag_t, pckbport_slot_t, int);

     void
     pckbport_set_inputhandler(pckbport_tag_t, pckbport_slot_t, pckbport_inputfcn, void *, char *);

     void
     pckbport_flush(pckbport_tag_t, pckbport_slot_t);

     int
     pckbport_poll_cmd(pckbport_tag_t, pckbport_slot_t, u_char *, int, int, u_char *, int);

     int
     pckbport_enqueue_cmd(pckbport_tag_t, pckbport_slot_t, u_char *, int, int, int, u_char *);

     int
     pckbport_poll_data(pckbport_tag_t, pckbport_slot_t);

     void
     pckbport_set_poll(pckbport_tag_t, pckbport_slot_t, int);

     int
     pckbport_xt_translation(pckbport_tag_t, pckbport_slot_t, int);

     void
     pckbport_slot_enable(pckbport_tag_t, pckbport_slot_t, int);

DESCRIPTION

     The machine-independent pckbport subsystem provides an interface layer corresponding to the serial keyboard and mouse interface used on the
     IBM PS/2 and many other machines.	It interfaces a controller driver such as pckbc(4) to device drivers such as pckbd(4) and pms(4).

     A single controller can have up to two ports (known as ``slots''), and these are identified by values of type pckbport_slot_t.  The values
     PCKBPORT_KBD_SLOT and PCKBPORT_AUX_SLOT should be used for keyboard and mouse ports respectively.	Each controller is identified by an opaque
     value of type pckbport_tag_t.

   Controller interface
     A PC keyboard controller registers itself by calling pckbport_attach(cookie, ops), with ops being a pointer to a struct pckbport_accessops
     containing pointers to functions for driving the controller, which will all be called with cookie as their first argument.  pckbport_attach()
     returns the pckbport_tag_t assigned to the controller.  The controller is then expected to call pckbport_attach_slot() for each slot with
     which it is equipped, passing the struct device * corresponding to the controller.  This function returns a pointer to the child device
     attached to the slot, or NULL if no such device was attached.

     The elements of struct pckbport_accessops each take as their first two arguments the cookie passed to pckbport_attach() and the slot in ques-
     tion.  The elements are:

     int (*t_xt_translation)(void *cookie, pckbport_slot_t slot, int on)
		       If on is non-zero, enable, otherwise disable, AT-to-XT keycode translation on the slot specified.  Returns 1 on success, 0
		       on failure (or if the controller does not support such translation).

     int (*t_send_devcmd)(void *cookie, pckbport_slot_t slot, u_char byte)
		       Send a single byte to the device without waiting for completion.  Returns 1 on success, 0 on failure.

     int (*t_poll_data1)(void *cookie, pckbport_slot_t slot)
		       Wait for and return one byte of data from the device, without using interrupts.	This function will only be called after
		       (*t_set_poll)() has been used to put the slot in polling mode.  If no data are forthcoming from the device after about
		       100ms, return -1.

     void (*t_slot_enable)(void *cookie, pckbport_slot_t slot, int on)
		       If on is non-zero, enable, otherwise disable, the slot.	If a slot is disabled, it can be powered down, and is not expected
		       to generate any interrupts.  When first attached, ports should be disabled.

     void (*t_intr_establish)(void *cookie, pckbport_slot_t slot)
		       Set up an interrupt handler for the slot.  Called when a device gets attached to it.

     void (*t_set_poll)(void *cookie, pckbport_slot_t slot, int on)
		       If on is non-zero, enable, otherwise disable, polling mode on the slot.	In polling mode, data received from the device are
		       provided to (*t_poll_data1)() and not passed to pckbportintr(), whether or not interrupts are enabled.  In non-polling
		       mode, data from the device are expected to cause interrupts.  The controller interrupt handler should call
		       pckbportintr(tag, slot, byte) once for each byte received from the device.  When first attached, a port should be in non-
		       polling mode.

   Device interface
     Devices that attach to pckbport controllers do so using the normal autoconf(9) mechanism.	Their (*ca_match)() and (*ca_attach)() functions
     get passed a struct pckbport_attach_args which contains the controller and slot number where the device was found.  Device drivers can use
     the following functions to communicate with the controller.  Each takes tag and slot arguments to specify the slot to be acted on.

     pckbport_set_inputhandler(tag, slot, fn, arg, name)
		       Arrange for fn to be called with argument arg whenever an unsolicited byte is received from the slot.  The function will be
		       called at spltty().

     pckbport_flush(tag, slot)
		       Ensure that there is no pending input from the slot.

     pckbport_poll_cmd(tag, slot, cmd, len, responselen, respbuf, slow)
		       Issue a complete device command, cmd, len bytes long, expecting a response responselen bytes long, which will be placed in
		       respbuf.  If slow is true, the command is expected to take over a second to execute.  pckbport_poll_cmd() handles getting
		       an acknowledgement from the device and retrying the command if necessary.  Returns 0 on success, and an error value on
		       failure.  This function should only be called during autoconfiguration or when the slot has been placed into polling mode
		       by pckbport_set_poll().

     pckbport_enqueue_cmd(tag, slot, cmd, len, responselen, sync, respbuf)
		       Issue a complete device command, cmd, len bytes long, expecting a response responselen bytes long, which will be places in
		       respbuf.  If sync is true, pckbport_enqueue_cmd() waits for the command to complete before returning, otherwise it returns
		       immediately.  It is not safe to set sync when calling from an interrupt context.  The pckbport layer handles getting an
		       acknowledgement from the device and retrying the command if necessary.  Returns 0 on success, and an error value on fail-
		       ure.

     pckbport_poll_data(tag, slot)
		       Low-level command to poll for a single byte of data from the device, but ignoring bytes that are part of the response to a
		       command issued through pckbport_enqueue_command().

     pckbport_set_poll(tag, slot, on)
		       If on is true, enable polling on the slot, otherwise disable it.  In polling mode, pckbport_poll_cmd() can be used to issue
		       commands and pckbport_poll_data() to read unsolicited data, without enabling interrupts.  In non-polling mode, commands
		       should be issued using pckbport_enqueue_cmd(), unsolicited data are handled by the input function, and disabling interrupts
		       will suspend pckbport operation.

     pckbport_xt_translation(tag, slot, on)
		       Passthrough of (*t_xt_translation)() (see above).

     pckbport_slot(enable, tag, slot, on)
		       Passthrough of (*t_slot_enable)() (see above).

   Console interface
     On systems that can attach consoles through pckbport, the controller's console attachment function (called very early in autoconfiguration)
     calls pckbport_cnattach(cookie, ops, slot).  The first two arguments are the same as for pckbport_attach(), while the third indicates which
     slot the console keyboard is attached to.	pckbport_cnattach() either calls pckbd_cnattach(), if it is available, or
     pckbport_machdep_cnattach().  The latter allows machine-dependent keyboard drivers to attach themselves, but it is only called if a device
     with the 'pckbport_machdep_cnattach' attribute is configured into the system.  pckbport_cnattach() returns 0 on success and an error value on
     failure.  pckbport_machdep_cnattach() is expected to do the same.

CODE REFERENCES

     The pckbport code, and the pckbd(4) and pms(4) device drivers are in sys/dev/pckbport.

SEE ALSO

     pckbc(4), pckbd(4), pms(4), autoconf(9), spl(9)

HISTORY

     The pckbport system appeared in NetBSD 2.0.  Before that, pckbd(4) and pms(4) attached directly to pckbc(4) without any sensible way of using
     a different controller.

BSD
								  August 5, 2004							       BSD