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      1  1.5     skrll /*	$NetBSD: bcm2835_mbox_subr.c,v 1.5 2017/12/10 21:38:26 skrll Exp $	*/
      2  1.1  jakllsch 
      3  1.1  jakllsch /*-
      4  1.1  jakllsch  * Copyright (c) 2012 The NetBSD Foundation, Inc.
      5  1.1  jakllsch  * All rights reserved.
      6  1.1  jakllsch  *
      7  1.1  jakllsch  * This code is derived from software contributed to The NetBSD Foundation
      8  1.1  jakllsch  * by Nick Hudson
      9  1.1  jakllsch  *
     10  1.1  jakllsch  * Redistribution and use in source and binary forms, with or without
     11  1.1  jakllsch  * modification, are permitted provided that the following conditions
     12  1.1  jakllsch  * are met:
     13  1.1  jakllsch  * 1. Redistributions of source code must retain the above copyright
     14  1.1  jakllsch  *    notice, this list of conditions and the following disclaimer.
     15  1.1  jakllsch  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.1  jakllsch  *    notice, this list of conditions and the following disclaimer in the
     17  1.1  jakllsch  *    documentation and/or other materials provided with the distribution.
     18  1.1  jakllsch  *
     19  1.1  jakllsch  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  1.1  jakllsch  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  1.1  jakllsch  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  1.1  jakllsch  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  1.1  jakllsch  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  1.1  jakllsch  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  1.1  jakllsch  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  1.1  jakllsch  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  1.1  jakllsch  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  1.1  jakllsch  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  1.1  jakllsch  * POSSIBILITY OF SUCH DAMAGE.
     30  1.1  jakllsch  */
     31  1.1  jakllsch 
     32  1.1  jakllsch #include <sys/cdefs.h>
     33  1.5     skrll __KERNEL_RCSID(0, "$NetBSD: bcm2835_mbox_subr.c,v 1.5 2017/12/10 21:38:26 skrll Exp $");
     34  1.1  jakllsch 
     35  1.1  jakllsch #include <sys/param.h>
     36  1.1  jakllsch #include <sys/systm.h>
     37  1.1  jakllsch #include <sys/device.h>
     38  1.1  jakllsch #include <sys/kernel.h>
     39  1.1  jakllsch #include <sys/timetc.h>
     40  1.1  jakllsch #include <sys/bus.h>
     41  1.1  jakllsch 
     42  1.1  jakllsch #include <arm/broadcom/bcm2835_mbox.h>
     43  1.1  jakllsch #include <arm/broadcom/bcm2835_mboxreg.h>
     44  1.1  jakllsch #include <arm/broadcom/bcm2835reg.h>
     45  1.1  jakllsch 
     46  1.1  jakllsch void
     47  1.1  jakllsch bcm2835_mbox_read(bus_space_tag_t iot, bus_space_handle_t ioh, uint8_t chan,
     48  1.1  jakllsch     uint32_t *data)
     49  1.1  jakllsch {
     50  1.1  jakllsch 	uint32_t mbox;
     51  1.1  jakllsch 
     52  1.3     skrll 	KASSERT((chan & 0xf) == chan);
     53  1.3     skrll 
     54  1.1  jakllsch 	for (;;) {
     55  1.1  jakllsch 		uint8_t rchan;
     56  1.1  jakllsch 		uint32_t rdata;
     57  1.1  jakllsch 
     58  1.2     skrll 		bus_space_barrier(iot, ioh, 0, BCM2835_MBOX_SIZE,
     59  1.2     skrll 		    BUS_SPACE_BARRIER_READ);
     60  1.1  jakllsch 
     61  1.1  jakllsch 		if ((bus_space_read_4(iot, ioh,
     62  1.1  jakllsch 		    BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_EMPTY) != 0)
     63  1.1  jakllsch 			continue;
     64  1.1  jakllsch 
     65  1.2     skrll 		mbox = bus_space_read_4(iot, ioh, BCM2835_MBOX0_READ);
     66  1.1  jakllsch 
     67  1.1  jakllsch 		rchan = BCM2835_MBOX_CHAN(mbox);
     68  1.1  jakllsch 		rdata = BCM2835_MBOX_DATA(mbox);
     69  1.1  jakllsch 
     70  1.1  jakllsch 		if (rchan == chan) {
     71  1.1  jakllsch 			*data = rdata;
     72  1.1  jakllsch 			return;
     73  1.1  jakllsch 		}
     74  1.1  jakllsch 	}
     75  1.1  jakllsch }
     76  1.1  jakllsch 
     77  1.1  jakllsch void
     78  1.1  jakllsch bcm2835_mbox_write(bus_space_tag_t iot, bus_space_handle_t ioh, uint8_t chan,
     79  1.1  jakllsch     uint32_t data)
     80  1.1  jakllsch {
     81  1.1  jakllsch 	uint32_t rdata;
     82  1.1  jakllsch 
     83  1.3     skrll 	KASSERT((chan & 0xf) == chan);
     84  1.3     skrll 	KASSERT((data & 0xf) == 0);
     85  1.1  jakllsch 	for (;;) {
     86  1.1  jakllsch 
     87  1.2     skrll 		bus_space_barrier(iot, ioh, 0, BCM2835_MBOX_SIZE,
     88  1.2     skrll 		    BUS_SPACE_BARRIER_READ);
     89  1.1  jakllsch 
     90  1.1  jakllsch 		if ((rdata = bus_space_read_4(iot, ioh,
     91  1.1  jakllsch 		    BCM2835_MBOX0_STATUS) & BCM2835_MBOX_STATUS_FULL) == 0)
     92  1.1  jakllsch 			break;
     93  1.1  jakllsch 	}
     94  1.1  jakllsch 
     95  1.2     skrll 	bus_space_write_4(iot, ioh, BCM2835_MBOX1_WRITE,
     96  1.2     skrll 	    BCM2835_MBOX_MSG(chan, data));
     97  1.1  jakllsch 
     98  1.2     skrll 	bus_space_barrier(iot, ioh, 0, BCM2835_MBOX_SIZE,
     99  1.2     skrll 	    BUS_SPACE_BARRIER_WRITE);
    100  1.1  jakllsch }
    101