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      1 /*	$NetBSD: clkctrl.c,v 1.7 2022/04/20 23:32:17 macallan Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2005 Michael Lorenz
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     19  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     25  * POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: clkctrl.c,v 1.7 2022/04/20 23:32:17 macallan Exp $");
     30 
     31 #include <sys/param.h>
     32 #include <sys/systm.h>
     33 #include <sys/device.h>
     34 #include <sys/kernel.h>
     35 
     36 #include <machine/autoconf.h>
     37 #include <machine/cpu.h>
     38 
     39 #include <sparc/sparc/vaddrs.h>
     40 
     41 static int clkctrl_match(device_t, cfdata_t, void *);
     42 static void clkctrl_attach(device_t, device_t, void *);
     43 
     44 CFATTACH_DECL_NEW(clkctrl, 0,
     45      clkctrl_match, clkctrl_attach, NULL, NULL);
     46 
     47 static void tadpole_cpu_sleep(void);
     48 volatile uint8_t *clkctrl_reg = NULL;
     49 
     50 static int
     51 clkctrl_match(device_t parent, cfdata_t cf, void *aux)
     52 {
     53 	union obio_attach_args *uoba = aux;
     54 
     55 	if ((uoba->uoba_isobio4 != 0) || (clkctrl_reg != NULL))
     56 		return (0);
     57 
     58 	return (strcmp("clk-ctrl", uoba->uoba_sbus.sa_name) == 0);
     59 }
     60 
     61 static void
     62 clkctrl_attach(device_t parent, device_t self, void *aux)
     63 {
     64 	union obio_attach_args *uoba = aux;
     65 	struct sbus_attach_args *sa = &uoba->uoba_sbus;
     66 	bus_space_handle_t bh;
     67 	struct cpu_info *cur;
     68 
     69 	if (clkctrl_reg != NULL) {
     70 		aprint_error("unable to attach more than once\n");
     71 		return;
     72 	}
     73 	if (sbus_bus_map(sa->sa_bustag,
     74 			 sa->sa_slot, sa->sa_offset,
     75 			 1,
     76 			 BUS_SPACE_MAP_LINEAR, &bh) != 0) {
     77 		aprint_error("unable to map register\n");
     78 		return;
     79 	}
     80 
     81 	clkctrl_reg = (volatile uint8_t *)bus_space_vaddr(sa->sa_bustag, bh);
     82 
     83 #ifdef DEBUG
     84 	printf(" reg: %x", (uint32_t)clkctrl_reg);
     85 #endif
     86 	cur = curcpu();
     87 	cur->idlespin = tadpole_cpu_sleep;
     88 
     89 	printf("\n");
     90 }
     91 
     92 /* ARGSUSED */
     93 static void
     94 tadpole_cpu_sleep(void)
     95 {
     96 
     97 	if (clkctrl_reg == 0)
     98 		return;
     99 	*clkctrl_reg = 0;
    100 }
    101