1 /*- 2 * Copyright (c) 2012, 2013 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Oleksandr Rybalko under sponsorship 6 * from the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/module.h> 37 #include <sys/time.h> 38 #include <sys/bus.h> 39 #include <sys/resource.h> 40 #include <sys/rman.h> 41 #include <sys/watchdog.h> 42 43 #include <machine/bus.h> 44 #include <machine/intr.h> 45 46 #include <dev/fdt/fdt_common.h> 47 #include <dev/ofw/openfirm.h> 48 #include <dev/ofw/ofw_bus.h> 49 #include <dev/ofw/ofw_bus_subr.h> 50 #include <machine/fdt.h> 51 52 #include <arm/freescale/imx/imx_wdogreg.h> 53 54 struct imx_wdog_softc { 55 struct mtx sc_mtx; 56 device_t sc_dev; 57 bus_space_tag_t sc_bst; 58 bus_space_handle_t sc_bsh; 59 struct resource *sc_res[2]; 60 uint32_t sc_timeout; 61 }; 62 63 static struct resource_spec imx_wdog_spec[] = { 64 { SYS_RES_MEMORY, 0, RF_ACTIVE }, 65 { SYS_RES_IRQ, 0, RF_ACTIVE }, 66 { -1, 0 } 67 }; 68 69 static void imx_watchdog(void *, u_int, int *); 70 static int imx_wdog_probe(device_t); 71 static int imx_wdog_attach(device_t); 72 73 static device_method_t imx_wdog_methods[] = { 74 DEVMETHOD(device_probe, imx_wdog_probe), 75 DEVMETHOD(device_attach, imx_wdog_attach), 76 DEVMETHOD_END 77 }; 78 79 static driver_t imx_wdog_driver = { 80 "imx_wdog", 81 imx_wdog_methods, 82 sizeof(struct imx_wdog_softc), 83 }; 84 static devclass_t imx_wdog_devclass; 85 DRIVER_MODULE(imx_wdog, simplebus, imx_wdog_driver, imx_wdog_devclass, 0, 0); 86 87 88 static void 89 imx_watchdog(void *arg, u_int cmd, int *error) 90 { 91 struct imx_wdog_softc *sc; 92 uint16_t reg; 93 int timeout; 94 95 sc = arg; 96 mtx_lock(&sc->sc_mtx); 97 98 /* Refresh counter, since we feels good */ 99 WRITE(sc, WDOG_SR_REG, WDOG_SR_STEP1); 100 WRITE(sc, WDOG_SR_REG, WDOG_SR_STEP2); 101 102 /* We don't require precession, so "-10" (/1024) is ok */ 103 timeout = (1 << ((cmd & WD_INTERVAL) - 10)) / 1000000; 104 if (timeout > 1 && timeout < 128) { 105 if (timeout != sc->sc_timeout) { 106 device_printf(sc->sc_dev, 107 "WARNING: watchdog can't be disabled!!!"); 108 sc->sc_timeout = timeout; 109 reg = READ(sc, WDOG_CR_REG); 110 reg &= ~WDOG_CR_WT_MASK; 111 reg |= (timeout << (WDOG_CR_WT_SHIFT + 1)) & 112 WDOG_CR_WT_MASK; 113 WRITE(sc, WDOG_CR_REG, reg); 114 /* Refresh counter */ 115 WRITE(sc, WDOG_SR_REG, WDOG_SR_STEP1); 116 WRITE(sc, WDOG_SR_REG, WDOG_SR_STEP2); 117 *error = 0; 118 } else { 119 *error = EOPNOTSUPP; 120 } 121 } else { 122 device_printf(sc->sc_dev, "Can not be disabled.\n"); 123 *error = EOPNOTSUPP; 124 } 125 mtx_unlock(&sc->sc_mtx); 126 127 } 128 129 static int 130 imx_wdog_probe(device_t dev) 131 { 132 133 if (!ofw_bus_is_compatible(dev, "fsl,imx51-wdt")) 134 return (ENXIO); 135 136 device_set_desc(dev, "Freescale i.MX5xx Watchdog Timer"); 137 return (0); 138 } 139 140 static int 141 imx_wdog_attach(device_t dev) 142 { 143 struct imx_wdog_softc *sc; 144 145 sc = device_get_softc(dev); 146 sc->sc_dev = dev; 147 148 if (bus_alloc_resources(dev, imx_wdog_spec, sc->sc_res)) { 149 device_printf(dev, "could not allocate resources\n"); 150 return (ENXIO); 151 } 152 153 mtx_init(&sc->sc_mtx, device_get_nameunit(dev), "imx_wdt", MTX_DEF); 154 155 sc->sc_dev = dev; 156 sc->sc_bst = rman_get_bustag(sc->sc_res[0]); 157 sc->sc_bsh = rman_get_bushandle(sc->sc_res[0]); 158 159 /* TODO: handle interrupt */ 160 161 EVENTHANDLER_REGISTER(watchdog_list, imx_watchdog, sc, 0); 162 return (0); 163 } 164