xref: /freebsd/sys/arm/freescale/imx/imx_machdep.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
1 /*-
2  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include "opt_platform.h"
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #define _ARM32_BUS_DMA_PRIVATE
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/reboot.h>
36 
37 #include <vm/vm.h>
38 #include <vm/pmap.h>
39 
40 #include <machine/armreg.h>
41 #include <machine/bus.h>
42 #include <machine/devmap.h>
43 #include <machine/machdep.h>
44 
45 #include <arm/freescale/imx/imx_machdep.h>
46 #include <arm/freescale/imx/imx_wdogreg.h>
47 
48 struct arm32_dma_range *
49 bus_dma_get_range(void)
50 {
51 
52 	return (NULL);
53 }
54 
55 int
56 bus_dma_get_range_nb(void)
57 {
58 
59 	return (0);
60 }
61 
62 /*
63  * This code which manipulates the watchdog hardware is here to implement
64  * cpu_reset() because the watchdog is the only way for software to reset the
65  * chip.  Why here and not in imx_wdog.c?  Because there's no requirement that
66  * the watchdog driver be compiled in, but it's nice to be able to reboot even
67  * if it's not.
68  */
69 void
70 imx_wdog_cpu_reset(vm_offset_t wdcr_physaddr)
71 {
72 	volatile uint16_t * pcr;
73 
74 	/*
75 	 * The deceptively simple write of WDOG_CR_WDE enables the watchdog,
76 	 * sets the timeout to its minimum value (half a second), and also
77 	 * clears the SRS bit which results in the SFTW (software-requested
78 	 * reset) bit being set in the watchdog status register after the reset.
79 	 * This is how software can distinguish a reset from a wdog timeout.
80 	 */
81 	if ((pcr = arm_devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
82 		printf("cpu_reset() can't find its control register... locking up now.");
83 	} else {
84 		*pcr = WDOG_CR_WDE;
85 	}
86 	for (;;)
87 		continue;
88 }
89 
90 u_int
91 imx_soc_family(void)
92 {
93 	return (imx_soc_type() >> IMXSOC_FAMSHIFT);
94 }
95 
96 
97