1/*- 2 * Copyright (c) 2009 Gallon Sylvestre. All rights reserved. 3 * Copyright (c) 2010 Greg Ansley. 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 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 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: releng/10.2/sys/arm/at91/at91_pit.c 266196 2014-05-15 21:21:47Z ian $"); 31 32#include <sys/param.h> 33#include <sys/bus.h> 34#include <sys/kernel.h> 35#include <sys/module.h> 36#include <sys/resource.h> 37#include <sys/systm.h> 38#include <sys/rman.h> 39#include <sys/time.h> 40#include <sys/timetc.h> 41#include <sys/watchdog.h> 42 43#include <machine/bus.h> 44#include <machine/cpu.h> 45#include <machine/cpufunc.h> 46#include <machine/frame.h> 47#include <machine/intr.h> 48#include <machine/resource.h> 49 50#include <arm/at91/at91var.h> 51#include <arm/at91/at91_pitreg.h> 52 53#ifdef FDT 54#include <dev/fdt/fdt_common.h> 55#include <dev/ofw/ofw_bus.h> 56#include <dev/ofw/ofw_bus_subr.h> 57#endif 58 59#ifndef PIT_PRESCALE 60#define PIT_PRESCALE (16) 61#endif 62 63static struct pit_softc { 64 struct resource *mem_res; /* Memory resource */ 65 void *intrhand; /* Interrupt handle */ 66 device_t sc_dev; 67} *sc; 68 69static uint32_t timecount = 0; 70static unsigned at91_pit_get_timecount(struct timecounter *tc); 71static int pit_intr(void *arg); 72 73static inline uint32_t 74RD4(struct pit_softc *sc, bus_size_t off) 75{ 76 77 return (bus_read_4(sc->mem_res, off)); 78} 79 80static inline void 81WR4(struct pit_softc *sc, bus_size_t off, uint32_t val) 82{ 83 84 bus_write_4(sc->mem_res, off, val); 85} 86 87void 88at91_pit_delay(int us) 89{ 90 int32_t cnt, last, piv; 91 uint64_t pit_freq; 92 const uint64_t mhz = 1E6; 93 94 if (sc == NULL) 95 return; 96 97 last = PIT_PIV(RD4(sc, PIT_PIIR)); 98 99 /* Max delay ~= 260s. @ 133Mhz */ 100 pit_freq = at91_master_clock / PIT_PRESCALE; 101 cnt = ((pit_freq * us) + (mhz -1)) / mhz; 102 cnt = (cnt <= 0) ? 1 : cnt; 103 104 while (cnt > 0) { 105 piv = PIT_PIV(RD4(sc, PIT_PIIR)); 106 cnt -= piv - last ; 107 if (piv < last) 108 cnt -= PIT_PIV(~0u) - last; 109 last = piv; 110 } 111} 112 113static struct timecounter at91_pit_timecounter = { 114 at91_pit_get_timecount, /* get_timecount */ 115 NULL, /* no poll_pps */ 116 0xffffffff, /* counter mask */ 117 0 / PIT_PRESCALE, /* frequency */ 118 "AT91SAM9 timer", /* name */ 119 1000 /* quality */ 120}; 121 122static int 123at91_pit_probe(device_t dev) 124{ 125#ifdef FDT 126 if (!ofw_bus_is_compatible(dev, "atmel,at91sam9260-pit")) 127 return (ENXIO); 128#endif 129 device_set_desc(dev, "AT91SAM9 PIT"); 130 return (0); 131} 132 133static int 134at91_pit_attach(device_t dev) 135{ 136 void *ih; 137 int rid, err = 0; 138 struct resource *irq; 139 140 sc = device_get_softc(dev); 141 sc->sc_dev = dev; 142 143 rid = 0; 144 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 145 RF_ACTIVE); 146 147 if (sc->mem_res == NULL) 148 panic("couldn't allocate register resources"); 149 150 rid = 0; 151 irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 1, 1, 1, 152 RF_ACTIVE | RF_SHAREABLE); 153 if (!irq) { 154 device_printf(dev, "could not allocate interrupt resources.\n"); 155 err = ENOMEM; 156 goto out; 157 } 158 159 /* Activate the interrupt. */ 160 err = bus_setup_intr(dev, irq, INTR_TYPE_CLK, pit_intr, NULL, NULL, 161 &ih); 162 163 at91_pit_timecounter.tc_frequency = at91_master_clock / PIT_PRESCALE; 164 tc_init(&at91_pit_timecounter); 165 166 /* Enable the PIT here. */ 167 WR4(sc, PIT_MR, PIT_PIV(at91_master_clock / PIT_PRESCALE / hz) | 168 PIT_EN | PIT_IEN); 169out: 170 return (err); 171} 172 173 174static int 175pit_intr(void *arg) 176{ 177 struct trapframe *fp = arg; 178 uint32_t icnt; 179 180 if (RD4(sc, PIT_SR) & PIT_PITS_DONE) { 181 icnt = RD4(sc, PIT_PIVR) >> 20; 182 183 /* Just add in the overflows we just read */ 184 timecount += PIT_PIV(RD4(sc, PIT_MR)) * icnt; 185 186 hardclock(TRAPF_USERMODE(fp), TRAPF_PC(fp)); 187 return (FILTER_HANDLED); 188 } 189 return (FILTER_STRAY); 190} 191 192static unsigned 193at91_pit_get_timecount(struct timecounter *tc) 194{ 195 uint32_t piir, icnt; 196 197 piir = RD4(sc, PIT_PIIR); /* Current count | over flows */ 198 icnt = piir >> 20; /* Overflows */ 199 return (timecount + PIT_PIV(piir) + PIT_PIV(RD4(sc, PIT_MR)) * icnt); 200} 201 202static device_method_t at91_pit_methods[] = { 203 DEVMETHOD(device_probe, at91_pit_probe), 204 DEVMETHOD(device_attach, at91_pit_attach), 205 DEVMETHOD_END 206}; 207 208static driver_t at91_pit_driver = { 209 "at91_pit", 210 at91_pit_methods, 211 sizeof(struct pit_softc), 212}; 213 214static devclass_t at91_pit_devclass; 215 216#ifdef FDT 217DRIVER_MODULE(at91_pit, simplebus, at91_pit_driver, at91_pit_devclass, NULL, 218 NULL); 219#else 220DRIVER_MODULE(at91_pit, atmelarm, at91_pit_driver, at91_pit_devclass, NULL, 221 NULL); 222#endif 223