2 * Copyright (c) 2012 Damjan Marion <dmarion@Freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/malloc.h>
37 #include <sys/timeet.h>
38 #include <sys/timetc.h>
39 #include <machine/bus.h>
42 #include <machine/machdep.h> /* For arm_set_delay */
45 #include <dev/ofw/openfirm.h>
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
49 #include <arm/ti/ti_prcm.h>
50 #include <arm/ti/ti_hwmods.h>
52 #include "am335x_dmtreg.h"
54 struct am335x_dmtimer_softc {
57 struct resource * tmr_mem_res;
59 struct resource * tmr_irq_res;
60 void *tmr_irq_handler;
62 uint32_t tclr; /* Cached TCLR register. */
64 struct timecounter tc;
67 int tmr_num; /* Hardware unit number. */
68 char tmr_name[12]; /* "DMTimerN", N = tmr_num */
71 static struct am335x_dmtimer_softc *am335x_dmtimer_et_sc = NULL;
72 static struct am335x_dmtimer_softc *am335x_dmtimer_tc_sc = NULL;
74 static void am335x_dmtimer_delay(int, void *);
77 * We use dmtimer2 for eventtimer and dmtimer3 for timecounter.
82 /* List of compatible strings for FDT tree */
83 static struct ofw_compat_data compat_data[] = {
84 {"ti,am335x-timer", 1},
85 {"ti,am335x-timer-1ms", 1},
89 #define DMTIMER_READ4(sc, reg) bus_read_4((sc)->tmr_mem_res, (reg))
90 #define DMTIMER_WRITE4(sc, reg, val) bus_write_4((sc)->tmr_mem_res, (reg), (val))
93 am335x_dmtimer_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
95 struct am335x_dmtimer_softc *sc;
96 uint32_t initial_count, reload_count;
101 * Stop the timer before changing it. This routine will often be called
102 * while the timer is still running, to either lengthen or shorten the
103 * current event time. We need to ensure the timer doesn't expire while
104 * we're working with it.
106 * Also clear any pending interrupt status, because it's at least
107 * theoretically possible that we're running in a primary interrupt
108 * context now, and a timer interrupt could be pending even before we
109 * stopped the timer. The more likely case is that we're being called
110 * from the et_event_cb() routine dispatched from our own handler, but
111 * it's not clear to me that that's the only case possible.
113 sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD);
114 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
115 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
118 reload_count = ((uint32_t)et->et_frequency * period) >> 32;
119 sc->tclr |= DMT_TCLR_AUTOLOAD;
125 initial_count = ((uint32_t)et->et_frequency * first) >> 32;
127 initial_count = reload_count;
130 * Set auto-reload and current-count values. This timer hardware counts
131 * up from the initial/reload value and interrupts on the zero rollover.
133 DMTIMER_WRITE4(sc, DMT_TLDR, 0xFFFFFFFF - reload_count);
134 DMTIMER_WRITE4(sc, DMT_TCRR, 0xFFFFFFFF - initial_count);
136 /* Enable overflow interrupt, and start the timer. */
137 DMTIMER_WRITE4(sc, DMT_IRQENABLE_SET, DMT_IRQ_OVF);
138 sc->tclr |= DMT_TCLR_START;
139 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
145 am335x_dmtimer_et_stop(struct eventtimer *et)
147 struct am335x_dmtimer_softc *sc;
151 /* Stop timer, disable and clear interrupt. */
152 sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD);
153 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
154 DMTIMER_WRITE4(sc, DMT_IRQENABLE_CLR, DMT_IRQ_OVF);
155 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
160 am335x_dmtimer_et_intr(void *arg)
162 struct am335x_dmtimer_softc *sc;
166 /* Ack the interrupt, and invoke the callback if it's still enabled. */
167 DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
168 if (sc->func.et.et_active)
169 sc->func.et.et_event_cb(&sc->func.et, sc->func.et.et_arg);
171 return (FILTER_HANDLED);
175 am335x_dmtimer_et_init(struct am335x_dmtimer_softc *sc)
177 KASSERT(am335x_dmtimer_et_sc == NULL, ("already have an eventtimer"));
180 * Setup eventtimer interrupt handling. Panic if anything goes wrong,
181 * because the system just isn't going to run without an eventtimer.
183 sc->tmr_irq_res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ,
184 &sc->tmr_irq_rid, RF_ACTIVE);
185 if (sc->tmr_irq_res == NULL)
186 panic("am335x_dmtimer: could not allocate irq resources");
187 if (bus_setup_intr(sc->dev, sc->tmr_irq_res, INTR_TYPE_CLK,
188 am335x_dmtimer_et_intr, NULL, sc, &sc->tmr_irq_handler) != 0)
189 panic("am335x_dmtimer: count not setup irq handler");
191 sc->func.et.et_name = sc->tmr_name;
192 sc->func.et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
193 sc->func.et.et_quality = 500;
194 sc->func.et.et_frequency = sc->sysclk_freq;
195 sc->func.et.et_min_period =
196 ((0x00000005LLU << 32) / sc->func.et.et_frequency);
197 sc->func.et.et_max_period =
198 (0xfffffffeLLU << 32) / sc->func.et.et_frequency;
199 sc->func.et.et_start = am335x_dmtimer_et_start;
200 sc->func.et.et_stop = am335x_dmtimer_et_stop;
201 sc->func.et.et_priv = sc;
203 am335x_dmtimer_et_sc = sc;
204 et_register(&sc->func.et);
210 am335x_dmtimer_tc_get_timecount(struct timecounter *tc)
212 struct am335x_dmtimer_softc *sc;
216 return (DMTIMER_READ4(sc, DMT_TCRR));
220 am335x_dmtimer_tc_init(struct am335x_dmtimer_softc *sc)
222 KASSERT(am335x_dmtimer_tc_sc == NULL, ("already have a timecounter"));
224 /* Set up timecounter, start it, register it. */
225 DMTIMER_WRITE4(sc, DMT_TSICR, DMT_TSICR_RESET);
226 while (DMTIMER_READ4(sc, DMT_TIOCP_CFG) & DMT_TIOCP_RESET)
229 sc->tclr |= DMT_TCLR_START | DMT_TCLR_AUTOLOAD;
230 DMTIMER_WRITE4(sc, DMT_TLDR, 0);
231 DMTIMER_WRITE4(sc, DMT_TCRR, 0);
232 DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
234 sc->func.tc.tc_name = sc->tmr_name;
235 sc->func.tc.tc_get_timecount = am335x_dmtimer_tc_get_timecount;
236 sc->func.tc.tc_counter_mask = ~0u;
237 sc->func.tc.tc_frequency = sc->sysclk_freq;
238 sc->func.tc.tc_quality = 500;
239 sc->func.tc.tc_priv = sc;
241 am335x_dmtimer_tc_sc = sc;
242 tc_init(&sc->func.tc);
245 arm_set_delay(am335x_dmtimer_delay, sc);
252 am335x_dmtimer_probe(device_t dev)
257 if (!ofw_bus_status_okay(dev))
260 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
264 * Get the hardware unit number (the N from ti,hwmods="timerN").
265 * If this isn't the hardware unit we're going to use for either the
266 * eventtimer or the timecounter, no point in instantiating the device.
268 tmr_num = ti_hwmods_get_unit(dev, "timer");
269 if (tmr_num != ET_TMR_NUM && tmr_num != TC_TMR_NUM)
272 snprintf(strbuf, sizeof(strbuf), "AM335x DMTimer%d", tmr_num);
273 device_set_desc_copy(dev, strbuf);
275 return(BUS_PROBE_DEFAULT);
279 am335x_dmtimer_attach(device_t dev)
281 struct am335x_dmtimer_softc *sc;
282 clk_ident_t timer_id;
285 sc = device_get_softc(dev);
288 /* Get the base clock frequency. */
289 if ((err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq)) != 0)
292 /* Enable clocks and power on the device. */
293 if ((timer_id = ti_hwmods_get_clock(dev)) == INVALID_CLK_IDENT)
295 if ((err = ti_prcm_clk_set_source(timer_id, SYSCLK_CLK)) != 0)
297 if ((err = ti_prcm_clk_enable(timer_id)) != 0)
300 /* Request the memory resources. */
301 sc->tmr_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
302 &sc->tmr_mem_rid, RF_ACTIVE);
303 if (sc->tmr_mem_res == NULL) {
307 sc->tmr_num = ti_hwmods_get_unit(dev, "timer");
308 snprintf(sc->tmr_name, sizeof(sc->tmr_name), "DMTimer%d", sc->tmr_num);
311 * Go set up either a timecounter or eventtimer. We wouldn't have
312 * attached if we weren't one or the other.
314 if (sc->tmr_num == ET_TMR_NUM)
315 am335x_dmtimer_et_init(sc);
316 else if (sc->tmr_num == TC_TMR_NUM)
317 am335x_dmtimer_tc_init(sc);
319 panic("am335x_dmtimer: bad timer number %d", sc->tmr_num);
324 static device_method_t am335x_dmtimer_methods[] = {
325 DEVMETHOD(device_probe, am335x_dmtimer_probe),
326 DEVMETHOD(device_attach, am335x_dmtimer_attach),
330 static driver_t am335x_dmtimer_driver = {
332 am335x_dmtimer_methods,
333 sizeof(struct am335x_dmtimer_softc),
336 static devclass_t am335x_dmtimer_devclass;
338 DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0);
339 MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1);
342 am335x_dmtimer_delay(int usec, void *arg)
344 struct am335x_dmtimer_softc *sc = arg;
346 uint32_t first, last;
348 /* Get the number of times to count */
349 counts = (usec + 1) * (sc->sysclk_freq / 1000000);
351 first = DMTIMER_READ4(sc, DMT_TCRR);
354 last = DMTIMER_READ4(sc, DMT_TCRR);
356 counts -= (int32_t)(last - first);
358 counts -= (int32_t)((0xFFFFFFFF - first) + last);
370 if (am335x_dmtimer_tc_sc == NULL) {
371 for (; usec > 0; usec--)
372 for (counts = 200; counts > 0; counts--)
373 /* Prevent gcc from optimizing out the loop */
377 am335x_dmtimer_delay(usec, am335x_dmtimer_tc_sc);