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      1 /*	$NetBSD: gfpic.c,v 1.2 2024/04/24 14:41:13 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2023 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Support for the Goldfish virtual Programmable Interrupt Controller.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: gfpic.c,v 1.2 2024/04/24 14:41:13 thorpej Exp $");
     38 
     39 #include <sys/types.h>
     40 #include <sys/systm.h>
     41 #include <sys/bus.h>
     42 
     43 #include <dev/goldfish/gfpicvar.h>
     44 
     45 /*
     46  * Goldfish PIC registers.
     47  */
     48 #define	GFPIC_STATUS		(0 << 2) /* pending interrupt count */
     49 #define	GFPIC_PENDING		(1 << 2) /* pending interrupt bitmask */
     50 #define	GFPIC_DISABLE_ALL	(2 << 2) /* disables / clears all interrupts */
     51 #define	GFPIC_DISABLE		(3 << 2) /* disable IRQs (bitmask) */
     52 #define	GFPIC_ENABLE		(4 << 2) /* enable IRQs (bitmask) */
     53 
     54 #define	REG_READ(sc, r)		\
     55 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (r))
     56 #define	REG_WRITE(sc, r, v)	\
     57 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (r), (v))
     58 
     59 /*
     60  * gfpic_attach --
     61  *	Attach a Goldfish virtual PIC.
     62  */
     63 void
     64 gfpic_attach(struct gfpic_softc *sc)
     65 {
     66 	aprint_naive("\n");
     67 	aprint_normal(": Google Goldfish PIC\n");
     68 
     69 	REG_WRITE(sc, GFPIC_DISABLE_ALL, 0);
     70 }
     71 
     72 /*
     73  * gfpic_enable --
     74  *	Enable the specified IRQ on a Goldfish virtual PIC.
     75  */
     76 void
     77 gfpic_enable(struct gfpic_softc *sc, int pirq)
     78 {
     79 	KASSERT(pirq >= 0);
     80 	KASSERT(pirq <= 31);
     81 
     82 	REG_WRITE(sc, GFPIC_ENABLE, (1U << pirq));
     83 }
     84 
     85 /*
     86  * gfpic_disable --
     87  *	Disable the specified IRQ on a Goldfish virtual PIC.
     88  */
     89 void
     90 gfpic_disable(struct gfpic_softc *sc, int pirq)
     91 {
     92 	KASSERT(pirq >= 0);
     93 	KASSERT(pirq <= 31);
     94 
     95 	REG_WRITE(sc, GFPIC_DISABLE, (1U << pirq));
     96 }
     97 
     98 /*
     99  * gfpic_pending --
    100  *	Return the next pending IRQ on a Goldfish virtual PIC,
    101  *	or -1 if there are none.
    102  */
    103 int
    104 gfpic_pending(struct gfpic_softc *sc)
    105 {
    106 	return ffs(REG_READ(sc, GFPIC_PENDING)) - 1;
    107 }
    108