exynos5_mct.c revision 257200
1/*- 2 * Copyright (c) 2013 Ruslan Bukin <br@bsdpad.com> 3 * 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 THE 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 THE 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/* 28 * This module just enables Exynos MCT, so ARMv7 Generic Timer will works 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: head/sys/arm/samsung/exynos/arch_timer.c 257200 2013-10-27 01:34:10Z ian $"); 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/bus.h> 37#include <sys/kernel.h> 38#include <sys/module.h> 39#include <sys/malloc.h> 40#include <sys/rman.h> 41#include <sys/timeet.h> 42#include <sys/timetc.h> 43#include <sys/watchdog.h> 44#include <machine/bus.h> 45#include <machine/cpu.h> 46#include <machine/intr.h> 47 48#include <dev/fdt/fdt_common.h> 49#include <dev/ofw/openfirm.h> 50#include <dev/ofw/ofw_bus.h> 51#include <dev/ofw/ofw_bus_subr.h> 52 53#include <machine/bus.h> 54#include <machine/fdt.h> 55 56#define MCT_CTRL_START (1 << 8) 57#define MCT_CTRL (0x240) 58#define MCT_WRITE_STAT (0x24C) 59 60struct arm_tmr_softc { 61 struct resource *tmr_res[1]; 62 bus_space_tag_t bst; 63 bus_space_handle_t bsh; 64}; 65 66static struct resource_spec arm_tmr_spec[] = { 67 { SYS_RES_MEMORY, 0, RF_ACTIVE }, /* Timer registers */ 68 { -1, 0 } 69}; 70 71static int 72arm_tmr_probe(device_t dev) 73{ 74 if (!ofw_bus_is_compatible(dev, "exynos,mct")) 75 return (ENXIO); 76 77 device_set_desc(dev, "Exynos MPCore Timer"); 78 return (BUS_PROBE_DEFAULT); 79} 80 81static int 82arm_tmr_attach(device_t dev) 83{ 84 struct arm_tmr_softc *sc; 85 int reg, i; 86 int mask; 87 88 sc = device_get_softc(dev); 89 90 if (bus_alloc_resources(dev, arm_tmr_spec, sc->tmr_res)) { 91 device_printf(dev, "could not allocate resources\n"); 92 return (ENXIO); 93 } 94 95 /* Timer interface */ 96 sc->bst = rman_get_bustag(sc->tmr_res[0]); 97 sc->bsh = rman_get_bushandle(sc->tmr_res[0]); 98 99 reg = bus_space_read_4(sc->bst, sc->bsh, MCT_CTRL); 100 reg |= MCT_CTRL_START; 101 bus_space_write_4(sc->bst, sc->bsh, MCT_CTRL, reg); 102 103 mask = (1 << 16); 104 105 /* Wait 10 times until written value is applied */ 106 for (i = 0; i < 10; i++) { 107 reg = bus_space_read_4(sc->bst, sc->bsh, MCT_WRITE_STAT); 108 if (reg & mask) { 109 bus_space_write_4(sc->bst, sc->bsh, 110 MCT_WRITE_STAT, mask); 111 return (0); 112 } 113 cpufunc_nullop(); 114 } 115 116 /* NOTREACHED */ 117 118 panic("Can't enable timer\n"); 119} 120 121static device_method_t arm_tmr_methods[] = { 122 DEVMETHOD(device_probe, arm_tmr_probe), 123 DEVMETHOD(device_attach, arm_tmr_attach), 124 { 0, 0 } 125}; 126 127static driver_t arm_tmr_driver = { 128 "arch_timer", 129 arm_tmr_methods, 130 sizeof(struct arm_tmr_softc), 131}; 132 133static devclass_t arm_tmr_devclass; 134 135DRIVER_MODULE(arch_timer, simplebus, arm_tmr_driver, arm_tmr_devclass, 0, 0); 136