at91_rst.c revision 331722 
1/*-
2 * Copyright (c) 2010 Greg Ansley.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#include "opt_platform.h"
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/11/sys/arm/at91/at91_rst.c 331722 2018-03-29 02:50:57Z eadler $");
30
31#include <sys/param.h>
32#include <sys/bus.h>
33#include <sys/kernel.h>
34#include <sys/module.h>
35#include <sys/rman.h>
36#include <sys/systm.h>
37
38#include <machine/bus.h>
39
40#include <arm/at91/at91var.h>
41#include <arm/at91/at91_rstreg.h>
42#include <arm/at91/at91board.h>
43
44#ifdef FDT
45#include <dev/fdt/fdt_common.h>
46#include <dev/ofw/ofw_bus.h>
47#include <dev/ofw/ofw_bus_subr.h>
48#define FDT_HACKS 1
49#endif
50
51#define RST_TIMEOUT (5)	/* Seconds to hold NRST for hard reset */
52#define RST_TICK (20)	/* sample NRST at hz/RST_TICK intervals */
53
54#ifndef FDT
55static int at91_rst_intr(void *arg);
56#endif
57
58static struct at91_rst_softc {
59	struct resource	*mem_res;	/* Memory resource */
60	struct resource	*irq_res;	/* IRQ resource */
61	void		*intrhand;	/* Interrupt handle */
62	struct callout	tick_ch;	/* Tick callout */
63	device_t	sc_dev;
64	u_int		shutdown;	/* Shutdown in progress */
65} *at91_rst_sc;
66
67static inline uint32_t
68RD4(struct at91_rst_softc *sc, bus_size_t off)
69{
70
71	return (bus_read_4(sc->mem_res, off));
72}
73
74static inline void
75WR4(struct at91_rst_softc *sc, bus_size_t off, uint32_t val)
76{
77
78	bus_write_4(sc->mem_res, off, val);
79}
80
81void cpu_reset_sam9g20(void) __attribute__((weak));
82void cpu_reset_sam9g20(void) {}
83
84void
85at91_rst_cpu_reset(void)
86{
87
88	if (at91_rst_sc) {
89		cpu_reset_sam9g20(); /* May be null */
90
91		WR4(at91_rst_sc, RST_MR,
92		    RST_MR_ERSTL(0xd) | RST_MR_URSTEN | RST_MR_KEY);
93
94		WR4(at91_rst_sc, RST_CR,
95		    RST_CR_PROCRST |
96		    RST_CR_PERRST  |
97		    RST_CR_EXTRST  |
98		    RST_CR_KEY);
99	}
100	while(1)
101		continue;
102}
103
104static int
105at91_rst_probe(device_t dev)
106{
107#ifdef FDT
108	if (!ofw_bus_is_compatible(dev, "atmel,at91sam9260-rstc"))
109		return (ENXIO);
110#endif
111
112	device_set_desc(dev, "AT91SAM9 Reset Controller");
113	return (0);
114}
115
116static int
117at91_rst_attach(device_t dev)
118{
119	struct at91_rst_softc *sc;
120	const char *cause;
121	int rid, err = 0;
122
123	at91_rst_sc = sc = device_get_softc(dev);
124	sc->sc_dev = dev;
125
126	callout_init(&sc->tick_ch, 0);
127
128	rid = 0;
129	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
130	    RF_ACTIVE);
131	if (sc->mem_res == NULL) {
132		device_printf(dev, "could not allocate memory resources.\n");
133		err = ENOMEM;
134		goto out;
135	}
136
137#ifndef FDT_HACKS
138	rid = 0;
139	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
140	    RF_ACTIVE | RF_SHAREABLE);
141	if (sc->irq_res == NULL) {
142		device_printf(dev, "could not allocate interrupt resources.\n");
143		err = ENOMEM;
144		goto out;
145	}
146
147	/* Activate the interrupt. */
148	err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
149	    at91_rst_intr, NULL, sc, &sc->intrhand);
150	if (err)
151		device_printf(dev, "could not establish interrupt handler.\n");
152#endif
153
154	WR4(at91_rst_sc, RST_MR, RST_MR_ERSTL(0xd) | RST_MR_URSIEN | RST_MR_KEY);
155
156	switch (RD4(sc, RST_SR) & RST_SR_RST_MASK) {
157		case	RST_SR_RST_POW:
158			cause = "Power On";
159			break;
160		case	RST_SR_RST_WAKE:
161			cause = "Wake Up";
162			break;
163		case	RST_SR_RST_WDT:
164			cause = "Watchdog";
165			break;
166		case	RST_SR_RST_SOFT:
167			cause = "Software Request";
168			break;
169		case	RST_SR_RST_USR:
170			cause = "External (User)";
171			break;
172		default:
173			cause = "Unknown";
174			break;
175	}
176
177	device_printf(dev, "Reset cause: %s.\n", cause);
178out:
179	return (err);
180}
181
182#ifndef FDT_HACKS
183static void
184at91_rst_tick(void *argp)
185{
186	struct at91_rst_softc *sc = argp;
187
188	if (sc->shutdown++ >= RST_TIMEOUT * RST_TICK) {
189		/* User released the button in morre than RST_TIMEOUT */
190		cpu_reset();
191	} else if ((RD4(sc, RST_SR) & RST_SR_NRSTL)) {
192		/* User released the button in less than RST_TIMEOUT */
193		sc->shutdown = 0;
194		device_printf(sc->sc_dev, "shutting down...\n");
195		shutdown_nice(0);
196	} else {
197		callout_reset(&sc->tick_ch, hz/RST_TICK, at91_rst_tick, sc);
198	}
199}
200
201static int
202at91_rst_intr(void *argp)
203{
204	struct at91_rst_softc *sc = argp;
205
206	if (RD4(sc, RST_SR) & RST_SR_URSTS) {
207		if (sc->shutdown == 0)
208			callout_reset(&sc->tick_ch, hz/RST_TICK, at91_rst_tick, sc);
209		return (FILTER_HANDLED);
210	}
211	return (FILTER_STRAY);
212}
213#endif
214
215static device_method_t at91_rst_methods[] = {
216	DEVMETHOD(device_probe, at91_rst_probe),
217	DEVMETHOD(device_attach, at91_rst_attach),
218	DEVMETHOD_END
219};
220
221static driver_t at91_rst_driver = {
222	"at91_rst",
223	at91_rst_methods,
224	sizeof(struct at91_rst_softc),
225};
226
227static devclass_t at91_rst_devclass;
228
229#ifdef FDT
230DRIVER_MODULE(at91_rst, simplebus, at91_rst_driver, at91_rst_devclass, NULL,
231    NULL);
232#else
233DRIVER_MODULE(at91_rst, atmelarm, at91_rst_driver, at91_rst_devclass, NULL,
234    NULL);
235#endif
236