freebsd-dev/sys/dev/hyperv/input/hv_kbd.c

/*-
 * Copyright (c) 2017 Microsoft Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/taskqueue.h>
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/syscallsubr.h>
#include <sys/sysproto.h>
#include <sys/sema.h>
#include <sys/signal.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/mutex.h>
#include <sys/callout.h>

#include <sys/kbio.h>
#include <dev/kbd/kbdreg.h>
#include <dev/kbd/kbdtables.h>

#include "dev/hyperv/input/hv_kbdc.h"

#define HVKBD_MTX_LOCK(_m) do {		\
	mtx_lock(_m);			\
} while (0)

#define HVKBD_MTX_UNLOCK(_m) do {	\
	mtx_unlock(_m);			\
} while (0)

#define HVKBD_MTX_ASSERT(_m, _t) do {	\
	mtx_assert(_m, _t);		\
} while (0)

#define	HVKBD_LOCK()		HVKBD_MTX_LOCK(&Giant)
#define	HVKBD_UNLOCK()		HVKBD_MTX_UNLOCK(&Giant)
#define	HVKBD_LOCK_ASSERT()	HVKBD_MTX_ASSERT(&Giant, MA_OWNED)

#define HVKBD_FLAG_POLLING	0x00000002

/* early keyboard probe, not supported */
static int
hvkbd_configure(int flags)
{
	return (0);
}

/* detect a keyboard, not used */
static int
hvkbd_probe(int unit, void *arg, int flags)
{
	return (ENXIO);
}

/* reset and initialize the device, not used */
static int
hvkbd_init(int unit, keyboard_t **kbdp, void *arg, int flags)
{
	DEBUG_HVKBD(*kbdp, "%s\n", __func__);
	return (ENXIO);
}

/* test the interface to the device, not used */
static int
hvkbd_test_if(keyboard_t *kbd)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (0);
}

/* finish using this keyboard, not used */
static int
hvkbd_term(keyboard_t *kbd)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (ENXIO);
}

/* keyboard interrupt routine, not used */
static int
hvkbd_intr(keyboard_t *kbd, void *arg)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (0);
}

/* lock the access to the keyboard, not used */
static int
hvkbd_lock(keyboard_t *kbd, int lock)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (1);
}

/* save the internal state, not used */
static int
hvkbd_get_state(keyboard_t *kbd, void *buf, size_t len)
{
	DEBUG_HVKBD(kbd,"%s\n",  __func__);
	return (len == 0) ? 1 : -1;
}

/* set the internal state, not used */
static int
hvkbd_set_state(keyboard_t *kbd, void *buf, size_t len)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (EINVAL);
}

static int
hvkbd_poll(keyboard_t *kbd, int on)
{
	hv_kbd_sc *sc = kbd->kb_data;

	HVKBD_LOCK();
	/*
	 * Keep a reference count on polling to allow recursive
	 * cngrab() during a panic for example.
	 */
	if (on)
		sc->sc_polling++;
	else if (sc->sc_polling > 0)
		sc->sc_polling--;

	if (sc->sc_polling != 0) {
		sc->sc_flags |= HVKBD_FLAG_POLLING;
	} else {
		sc->sc_flags &= ~HVKBD_FLAG_POLLING;
	}
	HVKBD_UNLOCK();
	return (0);
}

/*
 * Enable the access to the device; until this function is called,
 * the client cannot read from the keyboard.
 */
static int
hvkbd_enable(keyboard_t *kbd)
{
	HVKBD_LOCK();
	KBD_ACTIVATE(kbd);
	HVKBD_UNLOCK();
	return (0);
}

/* disallow the access to the device */
static int
hvkbd_disable(keyboard_t *kbd)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	HVKBD_LOCK();
	KBD_DEACTIVATE(kbd);
	HVKBD_UNLOCK();
	return (0);
}

static void
hvkbd_do_poll(hv_kbd_sc *sc, uint8_t wait)
{
	while (!hv_kbd_prod_is_ready(sc)) {
		hv_kbd_read_channel(sc->hs_chan, sc);
		if (!wait)
			break;
	}
}

/* check if data is waiting */
/* Currently unused. */
static int
hvkbd_check(keyboard_t *kbd)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	return (0);
}

/* check if char is waiting */
static int
hvkbd_check_char_locked(keyboard_t *kbd)
{
	HVKBD_LOCK_ASSERT();
	if (!KBD_IS_ACTIVE(kbd))
		return (FALSE);

	hv_kbd_sc *sc = kbd->kb_data;
	if (sc->sc_flags & HVKBD_FLAG_POLLING)
		hvkbd_do_poll(sc, 0);
	if (hv_kbd_prod_is_ready(sc)) {
		return (TRUE);
	}
	return (FALSE);
}

static int
hvkbd_check_char(keyboard_t *kbd)
{
	int result;

	HVKBD_LOCK();
	result = hvkbd_check_char_locked(kbd);
	HVKBD_UNLOCK();

	return (result);
}

/* read char from the keyboard */
static uint32_t
hvkbd_read_char_locked(keyboard_t *kbd, int wait)
{
	uint32_t scancode = NOKEY;
	keystroke ks;
	hv_kbd_sc *sc = kbd->kb_data;
	HVKBD_LOCK_ASSERT();

	if (!KBD_IS_ACTIVE(kbd) || !hv_kbd_prod_is_ready(sc))
		return (NOKEY);
	if (sc->sc_mode == K_RAW) {
		if (hv_kbd_fetch_top(sc, &ks)) {
			return (NOKEY);
		}
		if ((ks.info & IS_E0) || (ks.info & IS_E1)) {
			/**
			 * Emulate the generation of E0 or E1 scancode,
			 * the real scancode will be consumed next time.
			 */
			if (ks.info & IS_E0) {
				scancode = XTKBD_EMUL0;
				ks.info &= ~IS_E0;
			} else if (ks.info & IS_E1) {
				scancode = XTKBD_EMUL1;
				ks.info &= ~IS_E1;
			}
			/**
			 * Change the top item to avoid encountering
			 * E0 or E1 twice.
			 */
			hv_kbd_modify_top(sc, &ks);
		} else if (ks.info & IS_UNICODE) {
			/**
			 * XXX: Hyperv host send unicode to VM through
			 * 'Type clipboard text', the mapping from
			 * unicode to scancode depends on the keymap.
			 * It is so complicated that we do not plan to
			 * support it yet.
			 */
			if (bootverbose)
				device_printf(sc->dev, "Unsupported unicode\n");
			hv_kbd_remove_top(sc);
			return (NOKEY);
		} else {
			scancode = ks.makecode;
			if (ks.info & IS_BREAK) {
				scancode |= XTKBD_RELEASE;
			}
			hv_kbd_remove_top(sc);
		}
	} else {
		if (bootverbose)
			device_printf(sc->dev, "Unsupported mode: %d\n", sc->sc_mode);
	}
	++kbd->kb_count;
	DEBUG_HVKBD(kbd, "read scan: 0x%x\n", scancode);
	return scancode;
}

/* Currently wait is always false. */
static uint32_t
hvkbd_read_char(keyboard_t *kbd, int wait)
{
	uint32_t keycode;

	HVKBD_LOCK();
	keycode = hvkbd_read_char_locked(kbd, wait);
	HVKBD_UNLOCK();

	return (keycode);
}

/* clear the internal state of the keyboard */
static void
hvkbd_clear_state(keyboard_t *kbd)
{
	hv_kbd_sc *sc = kbd->kb_data;
	sc->sc_state &= LOCK_MASK;	/* preserve locking key state */
	sc->sc_flags &= ~HVKBD_FLAG_POLLING;
}

static int
hvkbd_ioctl_locked(keyboard_t *kbd, u_long cmd, caddr_t arg)
{
	int i;
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
        int ival;
#endif
	hv_kbd_sc *sc = kbd->kb_data;
	switch (cmd) {
	case KDGKBMODE:
		*(int *)arg = sc->sc_mode;
		break;
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
	case _IO('K', 7):
		ival = IOCPARM_IVAL(arg);
		arg = (caddr_t)&ival;
		/* FALLTHROUGH */
#endif
	case KDSKBMODE:		/* set keyboard mode */
		DEBUG_HVKBD(kbd, "expected mode: %x\n", *(int *)arg);
		switch (*(int *)arg) {
		case K_XLATE:
			if (sc->sc_mode != K_XLATE) {
				/* make lock key state and LED state match */
				sc->sc_state &= ~LOCK_MASK;
				sc->sc_state |= KBD_LED_VAL(kbd);
			}
			/* FALLTHROUGH */
		case K_RAW:
		case K_CODE:
			if (sc->sc_mode != *(int *)arg) {
				DEBUG_HVKBD(kbd, "mod changed to %x\n", *(int *)arg);
				if ((sc->sc_flags & HVKBD_FLAG_POLLING) == 0)
					hvkbd_clear_state(kbd);
				sc->sc_mode = *(int *)arg;
			}
			break;
		default:
			return (EINVAL);
		}
		break;
	case KDGKBSTATE:	/* get lock key state */
		*(int *)arg = sc->sc_state & LOCK_MASK;
		break;
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
	case _IO('K', 20):
		ival = IOCPARM_IVAL(arg);
		arg = (caddr_t)&ival;
		/* FALLTHROUGH */
#endif
	case KDSKBSTATE:		/* set lock key state */
		if (*(int *)arg & ~LOCK_MASK) {
			return (EINVAL);
		}
		sc->sc_state &= ~LOCK_MASK;
		sc->sc_state |= *(int *)arg;
		return hvkbd_ioctl_locked(kbd, KDSETLED, arg);
	case KDGETLED:			/* get keyboard LED */
		*(int *)arg = KBD_LED_VAL(kbd);
		break;
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
    defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
	case _IO('K', 66):
		ival = IOCPARM_IVAL(arg);
		arg = (caddr_t)&ival;
		/* FALLTHROUGH */
#endif
	case KDSETLED:			/* set keyboard LED */
		/* NOTE: lock key state in "sc_state" won't be changed */
		if (*(int *)arg & ~LOCK_MASK)
			return (EINVAL);

		i = *(int *)arg;

		/* replace CAPS LED with ALTGR LED for ALTGR keyboards */
		if (sc->sc_mode == K_XLATE &&
		    kbd->kb_keymap->n_keys > ALTGR_OFFSET) {
			if (i & ALKED)
				i |= CLKED;
			else
				i &= ~CLKED;
		}
		if (KBD_HAS_DEVICE(kbd)) {
			DEBUG_HVSC(sc, "setled 0x%x\n", *(int *)arg);
		}

		KBD_LED_VAL(kbd) = *(int *)arg;
		break;
	default:
		return (genkbd_commonioctl(kbd, cmd, arg));
	}
	return (0);
}

/* some useful control functions */
static int
hvkbd_ioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)
{
	DEBUG_HVKBD(kbd, "%s: %lx start\n", __func__, cmd);
	HVKBD_LOCK();
	int ret = hvkbd_ioctl_locked(kbd, cmd, arg);
	HVKBD_UNLOCK();
	DEBUG_HVKBD(kbd, "%s: %lx end %d\n", __func__, cmd, ret);
	return (ret);
}

/* read one byte from the keyboard if it's allowed */
/* Currently unused. */
static int
hvkbd_read(keyboard_t *kbd, int wait)
{
	DEBUG_HVKBD(kbd, "%s\n", __func__);
	HVKBD_LOCK_ASSERT();
	if (!KBD_IS_ACTIVE(kbd))
		return (-1);
	return hvkbd_read_char_locked(kbd, wait);
}

static keyboard_switch_t hvkbdsw = {
	.probe =	hvkbd_probe,		/* not used */
	.init =		hvkbd_init,
	.term =		hvkbd_term,		/* not used */
	.intr =		hvkbd_intr,		/* not used */
	.test_if =	hvkbd_test_if,		/* not used */
	.enable =	hvkbd_enable,
	.disable =	hvkbd_disable,
	.read =		hvkbd_read,
	.check =	hvkbd_check,
	.read_char =	hvkbd_read_char,
	.check_char =	hvkbd_check_char,
	.ioctl =	hvkbd_ioctl,
	.lock =		hvkbd_lock,		/* not used */
	.clear_state =	hvkbd_clear_state,
	.get_state =	hvkbd_get_state,	/* not used */
	.set_state =	hvkbd_set_state,	/* not used */
	.poll =		hvkbd_poll,
};

KEYBOARD_DRIVER(hvkbd, hvkbdsw, hvkbd_configure);

void
hv_kbd_intr(hv_kbd_sc *sc)
{
	uint32_t c;
	if ((sc->sc_flags & HVKBD_FLAG_POLLING) != 0)
		return;

	if (KBD_IS_ACTIVE(&sc->sc_kbd) &&
	    KBD_IS_BUSY(&sc->sc_kbd)) {
		/* let the callback function process the input */
		(sc->sc_kbd.kb_callback.kc_func) (&sc->sc_kbd, KBDIO_KEYINPUT,
		    sc->sc_kbd.kb_callback.kc_arg);
	} else {
		/* read and discard the input, no one is waiting for it */
		do {
			c = hvkbd_read_char(&sc->sc_kbd, 0);
		} while (c != NOKEY);
	}
}

int
hvkbd_driver_load(module_t mod, int what, void *arg)
{
	switch (what) {
	case MOD_LOAD:
		kbd_add_driver(&hvkbd_kbd_driver);
		break;
	case MOD_UNLOAD:
		kbd_delete_driver(&hvkbd_kbd_driver);
		break;
	}
	return (0);
}

int
hv_kbd_drv_attach(device_t dev)
{
	hv_kbd_sc *sc = device_get_softc(dev);
	int unit = device_get_unit(dev);
	keyboard_t *kbd = &sc->sc_kbd;
	keyboard_switch_t *sw;
	sw = kbd_get_switch(HVKBD_DRIVER_NAME);
	if (sw == NULL) {
		return (ENXIO);
	}

	kbd_init_struct(kbd, HVKBD_DRIVER_NAME, KB_OTHER, unit, 0, 0, 0);
	kbd->kb_data = (void *)sc;
	kbd_set_maps(kbd, &key_map, &accent_map, fkey_tab, nitems(fkey_tab));
	KBD_FOUND_DEVICE(kbd);
	hvkbd_clear_state(kbd);
	KBD_PROBE_DONE(kbd);
	KBD_INIT_DONE(kbd);
	sc->sc_mode = K_RAW;
	(*sw->enable)(kbd);

	if (kbd_register(kbd) < 0) {
		goto detach;
	}
	KBD_CONFIG_DONE(kbd);
#ifdef KBD_INSTALL_CDEV
        if (kbd_attach(kbd)) {
		goto detach;
	}
#endif
	if (bootverbose) {
		kbdd_diag(kbd, bootverbose);
	}
	return (0);
detach:
	hv_kbd_drv_detach(dev);
	return (ENXIO);
}

int
hv_kbd_drv_detach(device_t dev)
{
	int error = 0;
	hv_kbd_sc *sc = device_get_softc(dev);
	hvkbd_disable(&sc->sc_kbd);
	if (KBD_IS_CONFIGURED(&sc->sc_kbd)) {
		error = kbd_unregister(&sc->sc_kbd);
		if (error) {
			device_printf(dev, "WARNING: kbd_unregister() "
			    "returned non-zero! (ignored)\n");
		}
	}
#ifdef KBD_INSTALL_CDEV
	error = kbd_detach(&sc->sc_kbd);
#endif
	return (error);
}