xref: /freebsd/sys/arm/freescale/imx/imx_machdep.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include "opt_platform.h"
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/reboot.h>
37 #include <sys/devmap.h>
38 
39 #include <vm/vm.h>
40 #include <vm/pmap.h>
41 
42 #include <machine/armreg.h>
43 #include <machine/bus.h>
44 #include <machine/machdep.h>
45 
46 #include <arm/freescale/imx/imx_machdep.h>
47 #include <arm/freescale/imx/imx_wdogreg.h>
48 
49 SYSCTL_NODE(_hw, OID_AUTO, imx, CTLFLAG_RW, NULL, "i.MX container");
50 
51 static int last_reset_status;
52 SYSCTL_UINT(_hw_imx, OID_AUTO, last_reset_status, CTLFLAG_RD,
53     &last_reset_status, 0, "Last reset status register");
54 
55 SYSCTL_STRING(_hw_imx, OID_AUTO, last_reset_reason, CTLFLAG_RD,
56     "unknown", 0, "Last reset reason");
57 
58 /*
59  * This code which manipulates the watchdog hardware is here to implement
60  * cpu_reset() because the watchdog is the only way for software to reset the
61  * chip.  Why here and not in imx_wdog.c?  Because there's no requirement that
62  * the watchdog driver be compiled in, but it's nice to be able to reboot even
63  * if it's not.
64  */
65 void
66 imx_wdog_cpu_reset(vm_offset_t wdcr_physaddr)
67 {
68 	volatile uint16_t * pcr;
69 
70 	/*
71 	 * Trigger an immediate reset by clearing the SRS bit in the watchdog
72 	 * control register.  The reset happens on the next cycle of the wdog
73 	 * 32KHz clock, so hang out in a spin loop until the reset takes effect.
74 	 *
75 	 * Imx6 erratum ERR004346 says the SRS bit has to be cleared twice
76 	 * within the same cycle of the 32khz clock to reliably trigger the
77 	 * reset.  Writing it 3 times in a row ensures at least 2 of the writes
78 	 * happen in the same 32k clock cycle.
79 	 */
80 	if ((pcr = devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
81 		printf("cpu_reset() can't find its control register... locking up now.");
82 	} else {
83 		*pcr &= ~WDOG_CR_SRS;
84 		*pcr &= ~WDOG_CR_SRS;
85 		*pcr &= ~WDOG_CR_SRS;
86 	}
87 	for (;;)
88 		continue;
89 }
90 
91 void
92 imx_wdog_init_last_reset(vm_offset_t wdsr_phys)
93 {
94 	volatile uint16_t * psr;
95 
96 	if ((psr = devmap_ptov(wdsr_phys, sizeof(*psr))) == NULL)
97 		return;
98 	last_reset_status = *psr;
99 	if (last_reset_status & WDOG_RSR_SFTW) {
100 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "SoftwareReset";
101 	} else if (last_reset_status & WDOG_RSR_TOUT) {
102 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "WatchdogTimeout";
103 	} else if (last_reset_status & WDOG_RSR_POR) {
104 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "PowerOnReset";
105 	}
106 }
107 
108 u_int
109 imx_soc_family(void)
110 {
111 	return (imx_soc_type() >> IMXSOC_FAMSHIFT);
112 }
113 
114 
115