at91_rst.c revision 238369 
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 <sys/cdefs.h>
27__FBSDID("$FreeBSD: head/sys/arm/at91/at91_rst.c 238369 2012-07-11 17:11:07Z imp $");
28
29#include <sys/param.h>
30#include <sys/bus.h>
31#include <sys/kernel.h>
32#include <sys/module.h>
33#include <sys/rman.h>
34#include <sys/systm.h>
35
36#include <machine/bus.h>
37
38#include <arm/at91/at91var.h>
39#include <arm/at91/at91_rstreg.h>
40#include <arm/at91/at91board.h>
41
42#define RST_TIMEOUT (5)	/* Seconds to hold NRST for hard reset */
43#define RST_TICK (20)	/* sample NRST at hz/RST_TICK intervals */
44
45static int at91_rst_intr(void *arg);
46
47static struct at91_rst_softc {
48	struct resource	*mem_res;	/* Memory resource */
49	struct resource	*irq_res;	/* IRQ resource */
50	void		*intrhand;	/* Interrupt handle */
51	struct callout	tick_ch;	/* Tick callout */
52	device_t	sc_dev;
53	u_int		shutdown;	/* Shutdown in progress */
54} *at91_rst_sc;
55
56static inline uint32_t
57RD4(struct at91_rst_softc *sc, bus_size_t off)
58{
59
60	return (bus_read_4(sc->mem_res, off));
61}
62
63static inline void
64WR4(struct at91_rst_softc *sc, bus_size_t off, uint32_t val)
65{
66
67	bus_write_4(sc->mem_res, off, val);
68}
69
70void cpu_reset_sam9g20(void) __attribute__((weak));
71void cpu_reset_sam9g20(void) {}
72
73void
74at91_rst_cpu_reset(void)
75{
76
77	if (at91_rst_sc) {
78		cpu_reset_sam9g20(); /* May be null */
79
80		WR4(at91_rst_sc, RST_MR,
81		    RST_MR_ERSTL(0xd) | RST_MR_URSTEN | RST_MR_KEY);
82
83		WR4(at91_rst_sc, RST_CR,
84		    RST_CR_PROCRST |
85		    RST_CR_PERRST  |
86		    RST_CR_EXTRST  |
87		    RST_CR_KEY);
88	}
89	while(1)
90		continue;
91}
92
93static int
94at91_rst_probe(device_t dev)
95{
96
97	device_set_desc(dev, "AT91SAM9 Reset Controller");
98	return (0);
99}
100
101static int
102at91_rst_attach(device_t dev)
103{
104	struct at91_rst_softc *sc;
105	const char *cause;
106	int rid, err;
107
108	at91_rst_sc = sc = device_get_softc(dev);
109	sc->sc_dev = dev;
110
111	callout_init(&sc->tick_ch, 0);
112
113	rid = 0;
114	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
115	    RF_ACTIVE);
116	if (sc->mem_res == NULL) {
117		device_printf(dev, "could not allocate memory resources.\n");
118		err = ENOMEM;
119		goto out;
120	}
121	rid = 0;
122	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
123	    RF_ACTIVE | RF_SHAREABLE);
124	if (sc->irq_res == NULL) {
125		device_printf(dev, "could not allocate interrupt resources.\n");
126		err = ENOMEM;
127		goto out;
128	}
129
130	/* Activate the interrupt. */
131	err = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
132	    at91_rst_intr, NULL, sc, &sc->intrhand);
133	if (err)
134		device_printf(dev, "could not establish interrupt handler.\n");
135
136	WR4(at91_rst_sc, RST_MR, RST_MR_ERSTL(0xd) | RST_MR_URSIEN | RST_MR_KEY);
137
138	switch (RD4(sc, RST_SR) & RST_SR_RST_MASK) {
139		case	RST_SR_RST_POW:
140			cause = "Power On";
141			break;
142		case	RST_SR_RST_WAKE:
143			cause = "Wake Up";
144			break;
145		case	RST_SR_RST_WDT:
146			cause = "Watchdog";
147			break;
148		case	RST_SR_RST_SOFT:
149			cause = "Software Request";
150			break;
151		case	RST_SR_RST_USR:
152			cause = "External (User)";
153			break;
154		default:
155			cause = "Unknown";
156			break;
157	}
158
159	device_printf(dev, "Reset cause: %s.\n", cause);
160out:
161	return (err);
162}
163
164static void
165at91_rst_tick(void *argp)
166{
167	struct at91_rst_softc *sc = argp;
168
169	if (sc->shutdown++ >= RST_TIMEOUT * RST_TICK) {
170		/* User released the button in morre than RST_TIMEOUT */
171		cpu_reset();
172	} else if ((RD4(sc, RST_SR) & RST_SR_NRSTL)) {
173		/* User released the button in less than RST_TIMEOUT */
174		sc->shutdown = 0;
175		device_printf(sc->sc_dev, "shutting down...\n");
176		shutdown_nice(0);
177	} else {
178		callout_reset(&sc->tick_ch, hz/RST_TICK, at91_rst_tick, sc);
179	}
180}
181
182static int
183at91_rst_intr(void *argp)
184{
185	struct at91_rst_softc *sc = argp;
186
187	if (RD4(sc, RST_SR) & RST_SR_URSTS) {
188		if (sc->shutdown == 0)
189			callout_reset(&sc->tick_ch, hz/RST_TICK, at91_rst_tick, sc);
190		return (FILTER_HANDLED);
191	}
192	return (FILTER_STRAY);
193}
194
195static device_method_t at91_rst_methods[] = {
196	DEVMETHOD(device_probe, at91_rst_probe),
197	DEVMETHOD(device_attach, at91_rst_attach),
198	DEVMETHOD_END
199};
200
201static driver_t at91_rst_driver = {
202	"at91_rst",
203	at91_rst_methods,
204	sizeof(struct at91_rst_softc),
205};
206
207static devclass_t at91_rst_devclass;
208
209DRIVER_MODULE(at91_rst, atmelarm, at91_rst_driver, at91_rst_devclass, NULL,
210    NULL);
211