1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
|
/*-
* Copyright (c) 2012 Damjan Marion <dmarion@Freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <machine/bus.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <arm/ti/ti_prcm.h>
#include <arm/ti/ti_hwmods.h>
#include "am335x_dmtreg.h"
struct am335x_dmtimer_softc {
device_t dev;
int tmr_mem_rid;
struct resource * tmr_mem_res;
int tmr_irq_rid;
struct resource * tmr_irq_res;
void *tmr_irq_handler;
uint32_t sysclk_freq;
uint32_t tclr; /* Cached TCLR register. */
union {
struct timecounter tc;
struct eventtimer et;
} func;
int tmr_num; /* Hardware unit number. */
char tmr_name[12]; /* "DMTimerN", N = tmr_num */
};
static struct am335x_dmtimer_softc *am335x_dmtimer_et_sc = NULL;
static struct am335x_dmtimer_softc *am335x_dmtimer_tc_sc = NULL;
/*
* We use dmtimer2 for eventtimer and dmtimer3 for timecounter.
*/
#define ET_TMR_NUM 2
#define TC_TMR_NUM 3
/* List of compatible strings for FDT tree */
static struct ofw_compat_data compat_data[] = {
{"ti,am335x-timer", 1},
{"ti,am335x-timer-1ms", 1},
{NULL, 0},
};
#define DMTIMER_READ4(sc, reg) bus_read_4((sc)->tmr_mem_res, (reg))
#define DMTIMER_WRITE4(sc, reg, val) bus_write_4((sc)->tmr_mem_res, (reg), (val))
static int
am335x_dmtimer_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
{
struct am335x_dmtimer_softc *sc;
uint32_t initial_count, reload_count;
sc = et->et_priv;
/*
* Stop the timer before changing it. This routine will often be called
* while the timer is still running, to either lengthen or shorten the
* current event time. We need to ensure the timer doesn't expire while
* we're working with it.
*
* Also clear any pending interrupt status, because it's at least
* theoretically possible that we're running in a primary interrupt
* context now, and a timer interrupt could be pending even before we
* stopped the timer. The more likely case is that we're being called
* from the et_event_cb() routine dispatched from our own handler, but
* it's not clear to me that that's the only case possible.
*/
sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD);
DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
if (period != 0) {
reload_count = ((uint32_t)et->et_frequency * period) >> 32;
sc->tclr |= DMT_TCLR_AUTOLOAD;
} else {
reload_count = 0;
}
if (first != 0)
initial_count = ((uint32_t)et->et_frequency * first) >> 32;
else
initial_count = reload_count;
/*
* Set auto-reload and current-count values. This timer hardware counts
* up from the initial/reload value and interrupts on the zero rollover.
*/
DMTIMER_WRITE4(sc, DMT_TLDR, 0xFFFFFFFF - reload_count);
DMTIMER_WRITE4(sc, DMT_TCRR, 0xFFFFFFFF - initial_count);
/* Enable overflow interrupt, and start the timer. */
DMTIMER_WRITE4(sc, DMT_IRQENABLE_SET, DMT_IRQ_OVF);
sc->tclr |= DMT_TCLR_START;
DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
return (0);
}
static int
am335x_dmtimer_et_stop(struct eventtimer *et)
{
struct am335x_dmtimer_softc *sc;
sc = et->et_priv;
/* Stop timer, disable and clear interrupt. */
sc->tclr &= ~(DMT_TCLR_START | DMT_TCLR_AUTOLOAD);
DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
DMTIMER_WRITE4(sc, DMT_IRQENABLE_CLR, DMT_IRQ_OVF);
DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
return (0);
}
static int
am335x_dmtimer_et_intr(void *arg)
{
struct am335x_dmtimer_softc *sc;
sc = arg;
/* Ack the interrupt, and invoke the callback if it's still enabled. */
DMTIMER_WRITE4(sc, DMT_IRQSTATUS, DMT_IRQ_OVF);
if (sc->func.et.et_active)
sc->func.et.et_event_cb(&sc->func.et, sc->func.et.et_arg);
return (FILTER_HANDLED);
}
static int
am335x_dmtimer_et_init(struct am335x_dmtimer_softc *sc)
{
KASSERT(am335x_dmtimer_et_sc == NULL, ("already have an eventtimer"));
/*
* Setup eventtimer interrupt handling. Panic if anything goes wrong,
* because the system just isn't going to run without an eventtimer.
*/
sc->tmr_irq_res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ,
&sc->tmr_irq_rid, RF_ACTIVE);
if (sc->tmr_irq_res == NULL)
panic("am335x_dmtimer: could not allocate irq resources");
if (bus_setup_intr(sc->dev, sc->tmr_irq_res, INTR_TYPE_CLK,
am335x_dmtimer_et_intr, NULL, sc, &sc->tmr_irq_handler) != 0)
panic("am335x_dmtimer: count not setup irq handler");
sc->func.et.et_name = sc->tmr_name;
sc->func.et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
sc->func.et.et_quality = 500;
sc->func.et.et_frequency = sc->sysclk_freq;
sc->func.et.et_min_period =
((0x00000005LLU << 32) / sc->func.et.et_frequency);
sc->func.et.et_max_period =
(0xfffffffeLLU << 32) / sc->func.et.et_frequency;
sc->func.et.et_start = am335x_dmtimer_et_start;
sc->func.et.et_stop = am335x_dmtimer_et_stop;
sc->func.et.et_priv = sc;
am335x_dmtimer_et_sc = sc;
et_register(&sc->func.et);
return (0);
}
static unsigned
am335x_dmtimer_tc_get_timecount(struct timecounter *tc)
{
struct am335x_dmtimer_softc *sc;
sc = tc->tc_priv;
return (DMTIMER_READ4(sc, DMT_TCRR));
}
static int
am335x_dmtimer_tc_init(struct am335x_dmtimer_softc *sc)
{
KASSERT(am335x_dmtimer_tc_sc == NULL, ("already have a timecounter"));
/* Set up timecounter, start it, register it. */
DMTIMER_WRITE4(sc, DMT_TSICR, DMT_TSICR_RESET);
while (DMTIMER_READ4(sc, DMT_TIOCP_CFG) & DMT_TIOCP_RESET)
continue;
sc->tclr |= DMT_TCLR_START | DMT_TCLR_AUTOLOAD;
DMTIMER_WRITE4(sc, DMT_TLDR, 0);
DMTIMER_WRITE4(sc, DMT_TCRR, 0);
DMTIMER_WRITE4(sc, DMT_TCLR, sc->tclr);
sc->func.tc.tc_name = sc->tmr_name;
sc->func.tc.tc_get_timecount = am335x_dmtimer_tc_get_timecount;
sc->func.tc.tc_counter_mask = ~0u;
sc->func.tc.tc_frequency = sc->sysclk_freq;
sc->func.tc.tc_quality = 500;
sc->func.tc.tc_priv = sc;
am335x_dmtimer_tc_sc = sc;
tc_init(&sc->func.tc);
return (0);
}
static int
am335x_dmtimer_probe(device_t dev)
{
char strbuf[32];
int tmr_num;
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
return (ENXIO);
/*
* Get the hardware unit number (the N from ti,hwmods="timerN").
* If this isn't the hardware unit we're going to use for either the
* eventtimer or the timecounter, no point in instantiating the device.
*/
tmr_num = ti_hwmods_get_unit(dev, "timer");
if (tmr_num != ET_TMR_NUM && tmr_num != TC_TMR_NUM)
return (ENXIO);
snprintf(strbuf, sizeof(strbuf), "AM335x DMTimer%d", tmr_num);
device_set_desc_copy(dev, strbuf);
return(BUS_PROBE_DEFAULT);
}
static int
am335x_dmtimer_attach(device_t dev)
{
struct am335x_dmtimer_softc *sc;
clk_ident_t timer_id;
int err;
sc = device_get_softc(dev);
sc->dev = dev;
/* Get the base clock frequency. */
if ((err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq)) != 0)
return (err);
/* Enable clocks and power on the device. */
if ((timer_id = ti_hwmods_get_clock(dev)) == INVALID_CLK_IDENT)
return (ENXIO);
if ((err = ti_prcm_clk_set_source(timer_id, SYSCLK_CLK)) != 0)
return (err);
if ((err = ti_prcm_clk_enable(timer_id)) != 0)
return (err);
/* Request the memory resources. */
sc->tmr_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
&sc->tmr_mem_rid, RF_ACTIVE);
if (sc->tmr_mem_res == NULL) {
return (ENXIO);
}
sc->tmr_num = ti_hwmods_get_unit(dev, "timer");
snprintf(sc->tmr_name, sizeof(sc->tmr_name), "DMTimer%d", sc->tmr_num);
/*
* Go set up either a timecounter or eventtimer. We wouldn't have
* attached if we weren't one or the other.
*/
if (sc->tmr_num == ET_TMR_NUM)
am335x_dmtimer_et_init(sc);
else if (sc->tmr_num == TC_TMR_NUM)
am335x_dmtimer_tc_init(sc);
else
panic("am335x_dmtimer: bad timer number %d", sc->tmr_num);
return (0);
}
static device_method_t am335x_dmtimer_methods[] = {
DEVMETHOD(device_probe, am335x_dmtimer_probe),
DEVMETHOD(device_attach, am335x_dmtimer_attach),
{ 0, 0 }
};
static driver_t am335x_dmtimer_driver = {
"am335x_dmtimer",
am335x_dmtimer_methods,
sizeof(struct am335x_dmtimer_softc),
};
static devclass_t am335x_dmtimer_devclass;
DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0);
MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1);
void
DELAY(int usec)
{
struct am335x_dmtimer_softc *sc;
int32_t counts;
uint32_t first, last;
sc = am335x_dmtimer_tc_sc;
if (sc == NULL) {
for (; usec > 0; usec--)
for (counts = 200; counts > 0; counts--)
/* Prevent gcc from optimizing out the loop */
cpufunc_nullop();
return;
}
/* Get the number of times to count */
counts = (usec + 1) * (sc->sysclk_freq / 1000000);
first = DMTIMER_READ4(sc, DMT_TCRR);
while (counts > 0) {
last = DMTIMER_READ4(sc, DMT_TCRR);
if (last > first) {
counts -= (int32_t)(last - first);
} else {
counts -= (int32_t)((0xFFFFFFFF - first) + last);
}
first = last;
}
}
|