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("$FreeBSD$");
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
63 static struct pit_softc {
64 struct resource *mem_res; /* Memory resource */
65 void *intrhand; /* Interrupt handle */
66 device_t sc_dev;
67 } *sc;
68
69 static uint32_t timecount = 0;
70 static unsigned at91_pit_get_timecount(struct timecounter *tc);
71 static int pit_intr(void *arg);
72
73 static inline uint32_t
RD4(struct pit_softc * sc,bus_size_t off)74 RD4(struct pit_softc *sc, bus_size_t off)
75 {
76
77 return (bus_read_4(sc->mem_res, off));
78 }
79
80 static inline void
WR4(struct pit_softc * sc,bus_size_t off,uint32_t val)81 WR4(struct pit_softc *sc, bus_size_t off, uint32_t val)
82 {
83
84 bus_write_4(sc->mem_res, off, val);
85 }
86
87 void
at91_pit_delay(int us)88 at91_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
113 static 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
122 static int
at91_pit_probe(device_t dev)123 at91_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
133 static int
at91_pit_attach(device_t dev)134 at91_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);
169 out:
170 return (err);
171 }
172
173
174 static int
pit_intr(void * arg)175 pit_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
192 static unsigned
at91_pit_get_timecount(struct timecounter * tc)193 at91_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
202 static 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
208 static driver_t at91_pit_driver = {
209 "at91_pit",
210 at91_pit_methods,
211 sizeof(struct pit_softc),
212 };
213
214 static devclass_t at91_pit_devclass;
215
216 #ifdef FDT
217 DRIVER_MODULE(at91_pit, simplebus, at91_pit_driver, at91_pit_devclass, NULL,
218 NULL);
219 #else
220 DRIVER_MODULE(at91_pit, atmelarm, at91_pit_driver, at91_pit_devclass, NULL,
221 NULL);
222 #endif
223