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      1 /*	$NetBSD: virtctrl.c,v 1.2 2024/01/06 21:49:59 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2024 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 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: virtctrl.c,v 1.2 2024/01/06 21:49:59 thorpej Exp $");
     34 
     35 #include <sys/types.h>
     36 #include <sys/bus.h>
     37 #include <sys/device.h>
     38 #include <sys/reboot.h>
     39 #include <sys/systm.h>
     40 
     41 #include <machine/cpu.h>
     42 
     43 #include <virt68k/dev/mainbusvar.h>
     44 
     45 struct virtctrl_softc {
     46 	device_t		sc_dev;
     47 	bus_space_tag_t		sc_bst;
     48 	bus_space_handle_t	sc_bsh;
     49 };
     50 
     51 static const struct device_compatible_entry compat_data[] = {
     52 	{ .compat = "netbsd,qemu-virt-ctrl" },
     53 	DEVICE_COMPAT_EOL
     54 };
     55 
     56 #define	VIRTCTRL_REG_FEATURES	0x00
     57 #define	VIRTCTRL_REG_CMD	0x04
     58 
     59 #define	CMD_NOP			0
     60 #define	CMD_RESET		1
     61 #define	CMD_HALT		2
     62 #define	CMD_PANIC		3
     63 
     64 #define	REG_READ(sc, r)		\
     65 	bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (r))
     66 #define	REG_WRITE(sc, r, v)	\
     67 	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (r), (v))
     68 
     69 static void
     70 virtctrl_reset_handler(void *v, int howto)
     71 {
     72 	struct virtctrl_softc * const sc = v;
     73 
     74 	if (panicstr != NULL) {
     75 		/*
     76 		 * XXX N.B. This forces a shutdown, rather than
     77 		 * XXX a reboot.
     78 		 */
     79 		REG_WRITE(sc, VIRTCTRL_REG_CMD, CMD_PANIC);
     80 	} else if (howto & RB_HALT) {
     81 		REG_WRITE(sc, VIRTCTRL_REG_CMD, CMD_HALT);
     82 	} else {
     83 		REG_WRITE(sc, VIRTCTRL_REG_CMD, CMD_RESET);
     84 	}
     85 }
     86 
     87 static int
     88 virtctrl_match(device_t parent, cfdata_t cf, void *aux)
     89 {
     90 	struct mainbus_attach_args * const ma = aux;
     91 
     92 	return mainbus_compatible_match(ma, compat_data);
     93 }
     94 
     95 static void
     96 virtctrl_attach(device_t parent, device_t self, void *aux)
     97 {
     98 	struct virtctrl_softc * const sc = device_private(self);
     99 	struct mainbus_attach_args * const ma = aux;
    100 	uint32_t feat;
    101 
    102 	sc->sc_dev = self;
    103 	sc->sc_bst = ma->ma_st;
    104 	if (bus_space_map(sc->sc_bst, ma->ma_addr, ma->ma_size, 0,
    105 			  &sc->sc_bsh) != 0) {
    106 		aprint_error(": couldn't map registers\n");
    107 		return;
    108 	}
    109 
    110 	aprint_naive("\n");
    111 	aprint_normal(": Qemu Virtual System Controller\n");
    112 
    113 	feat = REG_READ(sc, VIRTCTRL_REG_FEATURES);
    114 	aprint_normal_dev(self, "features=0x%08x\n", feat);
    115 
    116 	cpu_set_reset_func(virtctrl_reset_handler, sc);
    117 }
    118 
    119 CFATTACH_DECL_NEW(virtctrl, sizeof(struct virtctrl_softc),
    120 	virtctrl_match, virtctrl_attach, NULL, NULL);
    121