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 <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/arm/at91/at91_pit.c 234281 2012-04-14 11:29:32Z marius $");
29
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/kernel.h>
33#include <sys/module.h>
34#include <sys/resource.h>
35#include <sys/systm.h>
36#include <sys/rman.h>
37#include <sys/time.h>
38#include <sys/timetc.h>
39#include <sys/watchdog.h>
40
41#include <machine/bus.h>
42#include <machine/cpu.h>
43#include <machine/cpufunc.h>
44#include <machine/frame.h>
45#include <machine/intr.h>
46#include <machine/resource.h>
47
48#include <arm/at91/at91var.h>
49#include <arm/at91/at91_pitreg.h>
50
51static struct pit_softc {
52 struct resource *mem_res; /* Memory resource */
53 void *intrhand; /* Interrupt handle */
54 device_t sc_dev;
55} *sc;
56
57static uint32_t timecount = 0;
58
59static inline uint32_t
60RD4(struct pit_softc *sc, bus_size_t off)
61{
62
63 return (bus_read_4(sc->mem_res, off));
64}
65
66static inline void
67WR4(struct pit_softc *sc, bus_size_t off, uint32_t val)
68{
69
70 bus_write_4(sc->mem_res, off, val);
71}
72
73static unsigned at91pit_get_timecount(struct timecounter *tc);
74static int pit_intr(void *arg);
75
76#ifndef PIT_PRESCALE
77#define PIT_PRESCALE (16)
78#endif
79
80static struct timecounter at91pit_timecounter = {
81 at91pit_get_timecount, /* get_timecount */
82 NULL, /* no poll_pps */
83 0xffffffff, /* counter mask */
84 0 / PIT_PRESCALE, /* frequency */
85 "AT91SAM9 timer", /* name */
86 1000 /* quality */
87};
88
89static int
90at91pit_probe(device_t dev)
91{
92
93 if (at91_is_sam9()) {
94 device_set_desc(dev, "AT91SAM9 PIT");
95 return (0);
96 }
97 return (ENXIO);
98}
99
100static int
101at91pit_attach(device_t dev)
102{
103 void *ih;
104 int rid, err = 0;
105 struct at91_softc *at91_sc;
106 struct resource *irq;
107
108 at91_sc = device_get_softc(device_get_parent(dev));
109 sc = device_get_softc(dev);
110 sc->sc_dev = dev;
111
112 rid = 0;
113 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
114 RF_ACTIVE);
115
116 if (sc->mem_res == NULL)
117 panic("couldn't allocate register resources");
118
119 rid = 0;
120 irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 1, 1, 1,
121 RF_ACTIVE | RF_SHAREABLE);
122 if (!irq) {
123 device_printf(dev, "could not allocate interrupt resources.\n");
124 err = ENOMEM;
125 goto out;
126 }
127
128 /* Activate the interrupt. */
129 err = bus_setup_intr(dev, irq, INTR_TYPE_CLK, pit_intr, NULL, NULL,
130 &ih);
131
132 at91pit_timecounter.tc_frequency = at91_master_clock / PIT_PRESCALE;
133 tc_init(&at91pit_timecounter);
134
135 /* Enable the PIT here. */
136 WR4(sc, PIT_MR, PIT_PIV(at91_master_clock / PIT_PRESCALE / hz) |
137 PIT_EN | PIT_IEN);
138out:
139 return (err);
140}
141
142static device_method_t at91pit_methods[] = {
143 DEVMETHOD(device_probe, at91pit_probe),
144 DEVMETHOD(device_attach, at91pit_attach),
145 DEVMETHOD_END
146};
147
148static driver_t at91pit_driver = {
149 "at91_pit",
150 at91pit_methods,
151 sizeof(struct pit_softc),
152};
153
154static devclass_t at91pit_devclass;
155
156DRIVER_MODULE(at91_pit, atmelarm, at91pit_driver, at91pit_devclass, NULL,
157 NULL);
158
159static int
160pit_intr(void *arg)
161{
162 struct trapframe *fp = arg;
163 uint32_t icnt;
164
165 if (RD4(sc, PIT_SR) & PIT_PITS_DONE) {
166 icnt = RD4(sc, PIT_PIVR) >> 20;
167
168 /* Just add in the overflows we just read */
169 timecount += PIT_PIV(RD4(sc, PIT_MR)) * icnt;
170
171 hardclock(TRAPF_USERMODE(fp), TRAPF_PC(fp));
172 return (FILTER_HANDLED);
173 }
174 return (FILTER_STRAY);
175}
176
177static unsigned
178at91pit_get_timecount(struct timecounter *tc)
179{
180 uint32_t piir, icnt;
181
182 piir = RD4(sc, PIT_PIIR); /* Current count | over flows */
183 icnt = piir >> 20; /* Overflows */
184 return (timecount + PIT_PIV(piir) + PIT_PIV(RD4(sc, PIT_MR)) * icnt);
185}
186
187void
188DELAY(int us)
189{
190 int32_t cnt, last, piv;
191 uint64_t pit_freq;
192 const uint64_t mhz = 1E6;
193
194 last = PIT_PIV(RD4(sc, PIT_PIIR));
195
196 /* Max delay ~= 260s. @ 133Mhz */
197 pit_freq = at91_master_clock / PIT_PRESCALE;
198 cnt = ((pit_freq * us) + (mhz -1)) / mhz;
199 cnt = (cnt <= 0) ? 1 : cnt;
200
201 while (cnt > 0) {
202 piv = PIT_PIV(RD4(sc, PIT_PIIR));
203 cnt -= piv - last ;
204 if (piv < last)
205 cnt -= PIT_PIV(~0u) - last;
206 last = piv;
207 }
208}
209
210/*
211 * The 3 next functions must be implement with the future PLL code.
212 */
213void
214cpu_startprofclock(void)
215{
216
217}
218
219void
220cpu_stopprofclock(void)
221{
222
223}
224
225void
226cpu_initclocks(void)
227{
228
229}