xref: /freebsd/sys/arm/freescale/imx/imx_machdep.c (revision af6a5351a1fdb1130f18be6c782c4d48916eb971)
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 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/reboot.h>
35 #include <sys/devmap.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/machdep.h>
43 
44 #include <arm/freescale/imx/imx_machdep.h>
45 #include <arm/freescale/imx/imx_wdogreg.h>
46 
47 SYSCTL_NODE(_hw, OID_AUTO, imx, CTLFLAG_RW, NULL, "i.MX container");
48 
49 static int last_reset_status;
50 SYSCTL_UINT(_hw_imx, OID_AUTO, last_reset_status, CTLFLAG_RD,
51     &last_reset_status, 0, "Last reset status register");
52 
53 SYSCTL_STRING(_hw_imx, OID_AUTO, last_reset_reason, CTLFLAG_RD,
54     "unknown", 0, "Last reset reason");
55 
56 /*
57  * This code which manipulates the watchdog hardware is here to implement
58  * cpu_reset() because the watchdog is the only way for software to reset the
59  * chip.  Why here and not in imx_wdog.c?  Because there's no requirement that
60  * the watchdog driver be compiled in, but it's nice to be able to reboot even
61  * if it's not.
62  */
63 void
64 imx_wdog_cpu_reset(vm_offset_t wdcr_physaddr)
65 {
66 	volatile uint16_t * pcr;
67 
68 	/*
69 	 * Trigger an immediate reset by clearing the SRS bit in the watchdog
70 	 * control register.  The reset happens on the next cycle of the wdog
71 	 * 32KHz clock, so hang out in a spin loop until the reset takes effect.
72 	 *
73 	 * Imx6 erratum ERR004346 says the SRS bit has to be cleared twice
74 	 * within the same cycle of the 32khz clock to reliably trigger the
75 	 * reset.  Writing it 3 times in a row ensures at least 2 of the writes
76 	 * happen in the same 32k clock cycle.
77 	 */
78 	if ((pcr = devmap_ptov(wdcr_physaddr, sizeof(*pcr))) == NULL) {
79 		printf("cpu_reset() can't find its control register... locking up now.");
80 	} else {
81 		*pcr &= ~WDOG_CR_SRS;
82 		*pcr &= ~WDOG_CR_SRS;
83 		*pcr &= ~WDOG_CR_SRS;
84 	}
85 	for (;;)
86 		continue;
87 }
88 
89 void
90 imx_wdog_init_last_reset(vm_offset_t wdsr_phys)
91 {
92 	volatile uint16_t * psr;
93 
94 	if ((psr = devmap_ptov(wdsr_phys, sizeof(*psr))) == NULL)
95 		return;
96 	last_reset_status = *psr;
97 	if (last_reset_status & WDOG_RSR_SFTW) {
98 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "SoftwareReset";
99 	} else if (last_reset_status & WDOG_RSR_TOUT) {
100 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "WatchdogTimeout";
101 	} else if (last_reset_status & WDOG_RSR_POR) {
102 		sysctl___hw_imx_last_reset_reason.oid_arg1 = "PowerOnReset";
103 	}
104 }
105 
106 u_int
107 imx_soc_family(void)
108 {
109 	return (imx_soc_type() >> IMXSOC_FAMSHIFT);
110 }
111 
112 
113