1 /* $NetBSD: ixp425_timer.c,v 1.15 2009/10/21 14:15:51 rmind Exp $ */
4 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
7 * Ichiro FUKUHARA <ichiro@ichiro.org>.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY ICHIRO FUKUHARA ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL ICHIRO FUKUHARA OR THE VOICES IN HIS HEAD BE LIABLE FOR
23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
41 #include <sys/resource.h>
43 #include <sys/timetc.h>
45 #include <machine/armreg.h>
46 #include <machine/bus.h>
47 #include <machine/cpu.h>
48 #include <machine/frame.h>
49 #include <machine/resource.h>
50 #include <machine/intr.h>
51 #include <arm/xscale/ixp425/ixp425reg.h>
52 #include <arm/xscale/ixp425/ixp425var.h>
54 static uint32_t counts_per_hz;
56 /* callback functions for intr_functions */
57 int ixpclk_intr(void *);
61 bus_addr_t sc_baseaddr;
62 bus_space_tag_t sc_iot;
63 bus_space_handle_t sc_ioh;
66 static unsigned ixp425_timer_get_timecount(struct timecounter *tc);
68 #ifndef IXP425_CLOCK_FREQ
69 #define COUNTS_PER_SEC 66666600 /* 66MHz */
71 #define COUNTS_PER_SEC IXP425_CLOCK_FREQ
73 #define COUNTS_PER_USEC ((COUNTS_PER_SEC / 1000000) + 1)
75 static struct ixpclk_softc *ixpclk_sc = NULL;
77 #define GET_TS_VALUE(sc) (*(volatile u_int32_t *) \
78 (IXP425_TIMER_VBASE + IXP425_OST_TS))
80 static struct timecounter ixp425_timer_timecounter = {
81 ixp425_timer_get_timecount, /* get_timecount */
82 NULL, /* no poll_pps */
83 ~0u, /* counter_mask */
84 COUNTS_PER_SEC, /* frequency */
85 "IXP4XX Timer", /* name */
90 ixpclk_probe(device_t dev)
92 device_set_desc(dev, "IXP4XX Timer");
97 ixpclk_attach(device_t dev)
99 struct ixpclk_softc *sc = device_get_softc(dev);
100 struct ixp425_softc *sa = device_get_softc(device_get_parent(dev));
105 sc->sc_iot = sa->sc_iot;
106 sc->sc_baseaddr = IXP425_TIMER_HWBASE;
108 if (bus_space_map(sc->sc_iot, sc->sc_baseaddr, 8, 0,
110 panic("%s: Cannot map registers", device_get_name(dev));
115 static device_method_t ixpclk_methods[] = {
116 DEVMETHOD(device_probe, ixpclk_probe),
117 DEVMETHOD(device_attach, ixpclk_attach),
121 static driver_t ixpclk_driver = {
124 sizeof(struct ixpclk_softc),
126 static devclass_t ixpclk_devclass;
128 DRIVER_MODULE(ixpclk, ixp, ixpclk_driver, ixpclk_devclass, 0, 0);
130 ixp425_timer_get_timecount(struct timecounter *tc)
134 ret = GET_TS_VALUE(sc);
141 * Initialize the clock and get them going.
146 struct ixpclk_softc* sc = ixpclk_sc;
147 struct resource *irq;
148 device_t dev = sc->sc_dev;
153 if (hz < 50 || COUNTS_PER_SEC % hz) {
154 printf("Cannot get %d Hz clock; using 100 Hz\n", hz);
157 tick = 1000000 / hz; /* number of microseconds between interrupts */
160 * We only have one timer available; stathz and profhz are
161 * always left as 0 (the upper-layer clock code deals with
165 printf("Cannot get %d Hz statclock\n", stathz);
169 printf("Cannot get %d Hz profclock\n", profhz);
172 /* Report the clock frequency. */
174 oldirqstate = disable_interrupts(PSR_I);
176 irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, IXP425_INT_TMR0,
177 IXP425_INT_TMR0, 1, RF_ACTIVE);
179 panic("Unable to setup the clock irq handler.\n");
181 bus_setup_intr(dev, irq, INTR_TYPE_CLK, ixpclk_intr, NULL,
184 /* Set up the new clock parameters. */
186 /* clear interrupt */
187 bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXP425_OST_STATUS,
188 OST_WARM_RESET | OST_WDOG_INT | OST_TS_INT |
189 OST_TIM1_INT | OST_TIM0_INT);
191 counts_per_hz = COUNTS_PER_SEC / hz;
193 /* reload value & Timer enable */
194 bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXP425_OST_TIM0_RELOAD,
195 (counts_per_hz & TIMERRELOAD_MASK) | OST_TIMER_EN);
197 tc_init(&ixp425_timer_timecounter);
198 restore_interrupts(oldirqstate);
206 * Delay for at least N microseconds.
211 u_int32_t first, last;
218 * Clamp the timeout at a maximum value (about 32 seconds with
219 * a 66MHz clock). *Nobody* should be delay()ing for anywhere
220 * near that length of time and if they are, they should be hung
223 if (n >= (0x80000000U / COUNTS_PER_USEC))
224 usecs = (0x80000000U / COUNTS_PER_USEC) - 1;
226 usecs = n * COUNTS_PER_USEC;
228 /* Note: Timestamp timer counts *up*, unlike the other timers */
229 first = GET_TS_VALUE();
232 last = GET_TS_VALUE();
233 usecs -= (int)(last - first);
241 * Handle the hardclock interrupt.
244 ixpclk_intr(void *arg)
246 struct ixpclk_softc* sc = ixpclk_sc;
247 struct trapframe *frame = arg;
249 bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXP425_OST_STATUS,
252 hardclock(TRAPF_USERMODE(frame), TRAPF_PC(frame));
253 return (FILTER_HANDLED);
257 cpu_startprofclock(void)
262 cpu_stopprofclock(void)