1 /*-
2 * Copyright (c) 2011 Jakub Wojciech Klama <jceel@FreeBSD.org>
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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.2/sys/arm/lpc/lpc_timer.c 266207 2014-05-16 02:21:51Z ian $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/malloc.h>
36 #include <sys/rman.h>
37 #include <sys/timetc.h>
38 #include <sys/timeet.h>
39 #include <machine/bus.h>
40 #include <machine/cpu.h>
41 #include <machine/intr.h>
42
43 #include <dev/fdt/fdt_common.h>
44 #include <dev/ofw/ofw_bus.h>
45 #include <dev/ofw/ofw_bus_subr.h>
46
47 #include <arm/lpc/lpcreg.h>
48 #include <arm/lpc/lpcvar.h>
49
50 struct lpc_timer_softc {
51 device_t lt_dev;
52 struct eventtimer lt_et;
53 struct resource * lt_res[5];
54 bus_space_tag_t lt_bst0;
55 bus_space_handle_t lt_bsh0;
56 bus_space_tag_t lt_bst1;
57 bus_space_handle_t lt_bsh1;
58 int lt_oneshot;
59 uint32_t lt_period;
60 };
61
62 static struct resource_spec lpc_timer_spec[] = {
63 { SYS_RES_MEMORY, 0, RF_ACTIVE },
64 { SYS_RES_MEMORY, 1, RF_ACTIVE },
65 { SYS_RES_IRQ, 0, RF_ACTIVE },
66 { SYS_RES_IRQ, 1, RF_ACTIVE },
67 { -1, 0 }
68 };
69
70 static struct lpc_timer_softc *timer_softc = NULL;
71 static int lpc_timer_initialized = 0;
72 static int lpc_timer_probe(device_t);
73 static int lpc_timer_attach(device_t);
74 static int lpc_timer_start(struct eventtimer *,
75 sbintime_t first, sbintime_t period);
76 static int lpc_timer_stop(struct eventtimer *et);
77 static unsigned lpc_get_timecount(struct timecounter *);
78 static int lpc_hardclock(void *);
79
80 #define timer0_read_4(sc, reg) \
81 bus_space_read_4(sc->lt_bst0, sc->lt_bsh0, reg)
82 #define timer0_write_4(sc, reg, val) \
83 bus_space_write_4(sc->lt_bst0, sc->lt_bsh0, reg, val)
84 #define timer0_clear(sc) \
85 do { \
86 timer0_write_4(sc, LPC_TIMER_TC, 0); \
87 timer0_write_4(sc, LPC_TIMER_PR, 0); \
88 timer0_write_4(sc, LPC_TIMER_PC, 0); \
89 } while(0)
90
91 #define timer1_read_4(sc, reg) \
92 bus_space_read_4(sc->lt_bst1, sc->lt_bsh1, reg)
93 #define timer1_write_4(sc, reg, val) \
94 bus_space_write_4(sc->lt_bst1, sc->lt_bsh1, reg, val)
95 #define timer1_clear(sc) \
96 do { \
97 timer1_write_4(sc, LPC_TIMER_TC, 0); \
98 timer1_write_4(sc, LPC_TIMER_PR, 0); \
99 timer1_write_4(sc, LPC_TIMER_PC, 0); \
100 } while(0)
101
102 static struct timecounter lpc_timecounter = {
103 .tc_get_timecount = lpc_get_timecount,
104 .tc_name = "LPC32x0 Timer1",
105 .tc_frequency = 0, /* will be filled later */
106 .tc_counter_mask = ~0u,
107 .tc_quality = 1000,
108 };
109
110 static int
111 lpc_timer_probe(device_t dev)
112 {
113
114 if (!ofw_bus_status_okay(dev))
115 return (ENXIO);
116
117 if (!ofw_bus_is_compatible(dev, "lpc,timer"))
118 return (ENXIO);
119
120 device_set_desc(dev, "LPC32x0 timer");
121 return (BUS_PROBE_DEFAULT);
122 }
123
124 static int
125 lpc_timer_attach(device_t dev)
126 {
127 void *intrcookie;
128 struct lpc_timer_softc *sc = device_get_softc(dev);
129 phandle_t node;
130 uint32_t freq;
131
132 if (timer_softc)
133 return (ENXIO);
134
135 timer_softc = sc;
136
137 if (bus_alloc_resources(dev, lpc_timer_spec, sc->lt_res)) {
138 device_printf(dev, "could not allocate resources\n");
139 return (ENXIO);
140 }
141
142 sc->lt_bst0 = rman_get_bustag(sc->lt_res[0]);
143 sc->lt_bsh0 = rman_get_bushandle(sc->lt_res[0]);
144 sc->lt_bst1 = rman_get_bustag(sc->lt_res[1]);
145 sc->lt_bsh1 = rman_get_bushandle(sc->lt_res[1]);
146
147 if (bus_setup_intr(dev, sc->lt_res[2], INTR_TYPE_CLK,
148 lpc_hardclock, NULL, sc, &intrcookie)) {
149 device_printf(dev, "could not setup interrupt handler\n");
150 bus_release_resources(dev, lpc_timer_spec, sc->lt_res);
151 return (ENXIO);
152 }
153
154 /* Enable timer clock */
155 lpc_pwr_write(dev, LPC_CLKPWR_TIMCLK_CTRL1,
156 LPC_CLKPWR_TIMCLK_CTRL1_TIMER0 |
157 LPC_CLKPWR_TIMCLK_CTRL1_TIMER1);
158
159 /* Get PERIPH_CLK encoded in parent bus 'bus-frequency' property */
160 node = ofw_bus_get_node(dev);
161 if (OF_getprop(OF_parent(node), "bus-frequency", &freq,
162 sizeof(pcell_t)) <= 0) {
163 bus_release_resources(dev, lpc_timer_spec, sc->lt_res);
164 bus_teardown_intr(dev, sc->lt_res[2], intrcookie);
165 device_printf(dev, "could not obtain base clock frequency\n");
166 return (ENXIO);
167 }
168
169 freq = fdt32_to_cpu(freq);
170
171 /* Set desired frequency in event timer and timecounter */
172 sc->lt_et.et_frequency = (uint64_t)freq;
173 lpc_timecounter.tc_frequency = (uint64_t)freq;
174
175 sc->lt_et.et_name = "LPC32x0 Timer0";
176 sc->lt_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
177 sc->lt_et.et_quality = 1000;
178 sc->lt_et.et_min_period = (0x00000002LLU << 32) / sc->lt_et.et_frequency;
179 sc->lt_et.et_max_period = (0xfffffffeLLU << 32) / sc->lt_et.et_frequency;
180 sc->lt_et.et_start = lpc_timer_start;
181 sc->lt_et.et_stop = lpc_timer_stop;
182 sc->lt_et.et_priv = sc;
183
184 et_register(&sc->lt_et);
185 tc_init(&lpc_timecounter);
186
187 /* Reset and enable timecounter */
188 timer1_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_RESET);
189 timer1_write_4(sc, LPC_TIMER_TCR, 0);
190 timer1_clear(sc);
191 timer1_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
192
193 /* DELAY() now can work properly */
194 lpc_timer_initialized = 1;
195
196 return (0);
197 }
198
199 static int
200 lpc_timer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
201 {
202 struct lpc_timer_softc *sc = (struct lpc_timer_softc *)et->et_priv;
203 uint32_t ticks;
204
205 if (period == 0) {
206 sc->lt_oneshot = 1;
207 sc->lt_period = 0;
208 } else {
209 sc->lt_oneshot = 0;
210 sc->lt_period = ((uint32_t)et->et_frequency * period) >> 32;
211 }
212
213 if (first == 0)
214 ticks = sc->lt_period;
215 else
216 ticks = ((uint32_t)et->et_frequency * first) >> 32;
217
218 /* Reset timer */
219 timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_RESET);
220 timer0_write_4(sc, LPC_TIMER_TCR, 0);
221
222 /* Start timer */
223 timer0_clear(sc);
224 timer0_write_4(sc, LPC_TIMER_MR0, ticks);
225 timer0_write_4(sc, LPC_TIMER_MCR, LPC_TIMER_MCR_MR0I | LPC_TIMER_MCR_MR0S);
226 timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
227 return (0);
228 }
229
230 static int
231 lpc_timer_stop(struct eventtimer *et)
232 {
233 struct lpc_timer_softc *sc = (struct lpc_timer_softc *)et->et_priv;
234
235 timer0_write_4(sc, LPC_TIMER_TCR, 0);
236 return (0);
237 }
238
239 static device_method_t lpc_timer_methods[] = {
240 DEVMETHOD(device_probe, lpc_timer_probe),
241 DEVMETHOD(device_attach, lpc_timer_attach),
242 { 0, 0 }
243 };
244
245 static driver_t lpc_timer_driver = {
246 "timer",
247 lpc_timer_methods,
248 sizeof(struct lpc_timer_softc),
249 };
250
251 static devclass_t lpc_timer_devclass;
252
253 DRIVER_MODULE(timer, simplebus, lpc_timer_driver, lpc_timer_devclass, 0, 0);
254
255 static int
256 lpc_hardclock(void *arg)
257 {
258 struct lpc_timer_softc *sc = (struct lpc_timer_softc *)arg;
259
260 /* Reset pending interrupt */
261 timer0_write_4(sc, LPC_TIMER_IR, 0xffffffff);
262
263 /* Start timer again */
264 if (!sc->lt_oneshot) {
265 timer0_clear(sc);
266 timer0_write_4(sc, LPC_TIMER_MR0, sc->lt_period);
267 timer0_write_4(sc, LPC_TIMER_TCR, LPC_TIMER_TCR_ENABLE);
268 }
269
270 if (sc->lt_et.et_active)
271 sc->lt_et.et_event_cb(&sc->lt_et, sc->lt_et.et_arg);
272
273 return (FILTER_HANDLED);
274 }
275
276 static unsigned
277 lpc_get_timecount(struct timecounter *tc)
278 {
279 return timer1_read_4(timer_softc, LPC_TIMER_TC);
280 }
281
282 void
283 DELAY(int usec)
284 {
285 uint32_t counter;
286 uint32_t first, last;
287 int val = (lpc_timecounter.tc_frequency / 1000000 + 1) * usec;
288
289 /* Timer is not initialized yet */
290 if (!lpc_timer_initialized) {
291 for (; usec > 0; usec--)
292 for (counter = 100; counter > 0; counter--)
293 ;
294 return;
295 }
296
297 first = lpc_get_timecount(&lpc_timecounter);
298 while (val > 0) {
299 last = lpc_get_timecount(&lpc_timecounter);
300 if (last < first) {
301 /* Timer rolled over */
302 last = first;
303 }
304
305 val -= (last - first);
306 first = last;
307 }
308 }
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