NAME

wskbd, wskbd_input, wskbd_rawinput, wskbd_cnattach, wskbd_cndetach, wskbddevprint — wscons keyboard support

SYNOPSIS

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wskbdvar.h>
#include <dev/wscons/wsksymdef.h>
#include <dev/wscons/wsksymvar.h>

void
wskbd_input(struct device *kbddev, u_int type, int value);

void
wskbd_rawinput(struct device *kbddev, u_char *buf, int len);

void
wskbd_cnattach(const struct wskbd_consops *consops, void *conscookie, const struct wskbd_mapdata *mapdata);

void
wskbd_cndetach(void);

int
wskbddevprint(void *aux, const char *pnp);

DESCRIPTION

The wskbd module is a component of the wscons(9) framework to provide machine-independent keyboard support. Most of the support is provided by the wskbd(4) device driver, which must be a child of the hardware device driver.

DATA TYPES

Keyboard drivers providing support for wscons keyboards will make use of the following data types:

kbd_t

An opaque type describing keyboard properties.

keysym_t

The wscons keyboard-independent symbolic representation of the keypress.

struct wskbd_accessops

A structure used to specify the keyboard access functions. All keyboards must provide this structure and pass it to the wskbd(4) child device. It has the following members:

	int	(*enable)(void *, int);
	void	(*set_leds)(void *, int);
	int	(*ioctl)(void *v, u_long cmd, void *data,
			int flag, struct lwp *l);

The enable member defines the function to be called to enable keypress passing to wscons. The set_leds member defined the function to be called to set the LEDs on the keyboard. The ioctl member defines the function to be called to perform keyboard-specific ioctl calls.

There is a void * cookie provided by the keyboard driver associated with these functions, which is passed to them when they are invoked.

struct wskbd_consops

A structure used to specify the keyboard console operations. All keyboards which can operate as a console must provide this structure and pass it to the wskbd(4) child device. If the keyboard cannot be a console, it is not necessary to specify this structure. It has the following members:

	void	(*getc)(void *, u_int *, int *);
	void	(*pollc)(void *, int);
	void	(*bell)(void *, u_int, u_int, u_int);

There is a void * cookie provided by the keyboard driver associated with these functions, which is passed to them when they are invoked.

struct wscons_keydesc

A structure used to describe a keyboard mapping table to convert keyboard-specific keycodes to wscons keysyms. It has the following members:

	kbd_t	name;		/* name of this map */
	kbd_t	base;		/* map this one is based on */
	int	map_size;	/* size of map */
	const	keysym_t *map;	/* the map itself */

struct wskbd_mapdata

A structure used to describe the keyboard layout and operation to interpret the keyboard layout. it contains the following members:

        const struct wscons_keydesc *keydesc;
        kbd_t layout;

struct wskbddev_attach_args

A structure used to attach the wskbd(4) child device. It has the following members:

	int console;
	const struct wskbd_mapdata *keymap;
	const struct wskbd_accessops *accessops;
	void *accesscookie;

Keymaps

Keymaps are a dense stream of keysym_t. A declaration has the following fields:

pos [cmd] normal [shift] [altgr] [shift-altgr]

The fields have the following meanings:

pos: Always specified as KC(pos) and starts the description of key pos.
cmd: If the command modifier (KS_Cmd_XXX) is active, the optional command cmd is invoked.
normal: The keysym if no modifiers are active.
shift: The keysym if the shift modifier is active.
altgr: The keysym if the alt-gr modifier is active.
shift-altgr: The keysym if the shift-alt-gr modifier is active.

If the keysym after pos is not KS_Cmd_XXX, then cmd is empty. The shift, altgr and shift-altgr fields are determined from previous fields if they are not specified. Therefore, there are four valid keysym declarations:

pos [cmd] normal

pos [cmd] normal shift

pos [cmd] normal shift altgr

pos [cmd] normal shift altgr shift-altgr

FUNCTIONS

wskbd_input(kbddev, type, value)

Pass the keypress of value value and type type to wscons keyboard driver. Valid values of type are:

WSCONS_EVENT_KEY_UP: Key released.
WSCONS_EVENT_KEY_DOWN: Key pressed.

wskbd_rawinput(kbddev, buf, len)

Pass the raw keypress in the buffer buf to the wscons keyboard driver. The buffer is len bytes long. This function should only be called if the kernel option WSDISPLAY_COMPAT_RAWKBD is enabled.

wskbd_cnattach(consops, conscookie, mapdata)

Attach this keyboard as the console input by specifying the console operations consops and the keyboard mapping table information in mapdata. The functions specified in consops will be called with conscookie as the first argument.

wskbd_cndetach()

Detach this keyboard as the console input.

wskbddevprint(aux, pnp)

The default wskbd printing routine used by config_found(). (see autoconf(9)).

AUTOCONFIGURATION

Keyboard drivers which want to use the wskbd module must be a parent to the wskbd(4) device and provide an attachment interface. To attach the wskbd(4) device, the keyboard driver must allocate and populate a wskbddev_attach_args structure with the supported operations and callbacks and call config_found() to perform the attach (see autoconf(9)). The keymap member points to the wskbd_mapdata structure which describes the keycode mapping operations. The accessops member points to the wskbd_accessops structure which describes the keyboard access operations. The console member is a boolean to indicate to wscons whether this keyboard will be used for console input.

OPERATION

If the keyboard belongs to the system console, it must register the wskbd_consops structure specifying the console operations via wskbd_cnattach() at console attach time.

When a keypress arrives from the keyboard, the keyboard driver must perform any necessary character decoding to wscons events and pass the events to wscons via wskbd_input(). If the kernel is compiled with the option WSDISPLAY_COMPAT_RAWKBD, then the keyboard driver must also pass the raw keyboard data to wscons via wskbd_rawinput().

The wscons framework calls back into the hardware driver by invoking the functions that are specified in the accessops structure. The enable() and set_leds() functions are relatively simple and self-explanatory. The ioctl() function is called by the wscons interface to perform keyboard-specific ioctl operations (see ioctl(2)). The argument cmd to the ioctl() function specifies the specific command to perform using the data data. Valid commands are listed in sys/dev/wscons/wsconsio.h.

CODE REFERENCES

The wscons subsystem is implemented within the directory sys/dev/wscons. The wskbd module itself is implement within the files sys/dev/wscons/wskbd.c and sys/dev/wscons/wskbdutil.c. ioctl(2) operations are listed in sys/dev/wscons/wsconsio.h.