at91_rst.c revision 237130
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 237130 2012-06-15 08:37:50Z 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 at91rst_intr(void *arg); 46 47static struct at91rst_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} *at91rst_sc; 55 56static inline uint32_t 57RD4(struct at91rst_softc *sc, bus_size_t off) 58{ 59 60 return (bus_read_4(sc->mem_res, off)); 61} 62 63static inline void 64WR4(struct at91rst_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 73static void 74at91rst_cpu_reset(void) 75{ 76 77 if (at91rst_sc) { 78 cpu_reset_sam9g20(); /* May be null */ 79 80 WR4(at91rst_sc, RST_MR, 81 RST_MR_ERSTL(0xd) | RST_MR_URSTEN | RST_MR_KEY); 82 83 WR4(at91rst_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 94at91rst_probe(device_t dev) 95{ 96 97 device_set_desc(dev, "AT91SAM9 Reset Controller"); 98 return (0); 99} 100 101static int 102at91rst_attach(device_t dev) 103{ 104 struct at91rst_softc *sc; 105 const char *cause; 106 int rid, err; 107 108 at91rst_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 at91rst_intr, NULL, sc, &sc->intrhand); 133 if (err) 134 device_printf(dev, "could not establish interrupt handler.\n"); 135 136 WR4(at91rst_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); 160 soc_data.reset = at91rst_cpu_reset; 161out: 162 return (err); 163} 164 165static void 166at91rst_tick(void *argp) 167{ 168 struct at91rst_softc *sc = argp; 169 170 if (sc->shutdown++ >= RST_TIMEOUT * RST_TICK) { 171 /* User released the button in morre than RST_TIMEOUT */ 172 cpu_reset(); 173 } else if ((RD4(sc, RST_SR) & RST_SR_NRSTL)) { 174 /* User released the button in less than RST_TIMEOUT */ 175 sc->shutdown = 0; 176 device_printf(sc->sc_dev, "shutting down...\n"); 177 shutdown_nice(0); 178 } else { 179 callout_reset(&sc->tick_ch, hz/RST_TICK, at91rst_tick, sc); 180 } 181} 182 183static int 184at91rst_intr(void *argp) 185{ 186 struct at91rst_softc *sc = argp; 187 188 if (RD4(sc, RST_SR) & RST_SR_URSTS) { 189 if (sc->shutdown == 0) 190 callout_reset(&sc->tick_ch, hz/RST_TICK, at91rst_tick, sc); 191 return (FILTER_HANDLED); 192 } 193 return (FILTER_STRAY); 194} 195 196static device_method_t at91rst_methods[] = { 197 DEVMETHOD(device_probe, at91rst_probe), 198 DEVMETHOD(device_attach, at91rst_attach), 199 DEVMETHOD_END 200}; 201 202static driver_t at91rst_driver = { 203 "at91_rst", 204 at91rst_methods, 205 sizeof(struct at91rst_softc), 206}; 207 208static devclass_t at91rst_devclass; 209 210DRIVER_MODULE(at91_rst, atmelarm, at91rst_driver, at91rst_devclass, NULL, 211 NULL); 212