xref: /freebsd/sys/arm/ti/am335x/am335x_dmtimer.c (revision f05cddf9)
1 /*-
2  * Copyright (c) 2012 Damjan Marion <dmarion@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("$FreeBSD$");
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/timeet.h>
38 #include <sys/timetc.h>
39 #include <sys/watchdog.h>
40 #include <machine/bus.h>
41 #include <machine/cpu.h>
42 #include <machine/frame.h>
43 #include <machine/intr.h>
44 
45 #include <dev/fdt/fdt_common.h>
46 #include <dev/ofw/openfirm.h>
47 #include <dev/ofw/ofw_bus.h>
48 #include <dev/ofw/ofw_bus_subr.h>
49 
50 #include <machine/bus.h>
51 #include <machine/fdt.h>
52 
53 #include <arm/ti/ti_prcm.h>
54 
55 #define AM335X_NUM_TIMERS	8
56 
57 #define DMTIMER_TIDR		0x00 /* Identification Register */
58 #define DMTIMER_TIOCP_CFG	0x10 /* Timer OCP Configuration Reg */
59 #define DMTIMER_IQR_EOI		0x20 /* Timer IRQ End-Of-Interrupt Reg */
60 #define DMTIMER_IRQSTATUS_RAW	0x24 /* Timer IRQSTATUS Raw Reg */
61 #define DMTIMER_IRQSTATUS	0x28 /* Timer IRQSTATUS Reg */
62 #define DMTIMER_IRQENABLE_SET	0x2c /* Timer IRQSTATUS Set Reg */
63 #define DMTIMER_IRQENABLE_CLR	0x30 /* Timer IRQSTATUS Clear Reg */
64 #define DMTIMER_IRQWAKEEN	0x34 /* Timer IRQ Wakeup Enable Reg */
65 #define DMTIMER_TCLR		0x38 /* Timer Control Register */
66 #define DMTIMER_TCRR		0x3C /* Timer Counter Register */
67 #define DMTIMER_TLDR		0x40 /* Timer Load Reg */
68 #define DMTIMER_TTGR		0x44 /* Timer Trigger Reg */
69 #define DMTIMER_TWPS		0x48 /* Timer Write Posted Status Reg */
70 #define DMTIMER_TMAR		0x4C /* Timer Match Reg */
71 #define DMTIMER_TCAR1		0x50 /* Timer Capture Reg */
72 #define DMTIMER_TSICR		0x54 /* Timer Synchr. Interface Control Reg */
73 #define DMTIMER_TCAR2		0x48 /* Timer Capture Reg */
74 
75 
76 struct am335x_dmtimer_softc {
77 	struct resource *	tmr_mem_res[AM335X_NUM_TIMERS];
78 	struct resource *	tmr_irq_res[AM335X_NUM_TIMERS];
79 	uint32_t		sysclk_freq;
80 	struct am335x_dmtimer {
81 		bus_space_tag_t		bst;
82 		bus_space_handle_t	bsh;
83 		struct eventtimer	et;
84 	} t[AM335X_NUM_TIMERS];
85 };
86 
87 static struct resource_spec am335x_dmtimer_mem_spec[] = {
88 	{ SYS_RES_MEMORY,   0,  RF_ACTIVE },
89 	{ SYS_RES_MEMORY,   1,  RF_ACTIVE },
90 	{ SYS_RES_MEMORY,   2,  RF_ACTIVE },
91 	{ SYS_RES_MEMORY,   3,  RF_ACTIVE },
92 	{ SYS_RES_MEMORY,   4,  RF_ACTIVE },
93 	{ SYS_RES_MEMORY,   5,  RF_ACTIVE },
94 	{ SYS_RES_MEMORY,   6,  RF_ACTIVE },
95 	{ SYS_RES_MEMORY,   7,  RF_ACTIVE },
96 	{ -1,               0,  0 }
97 };
98 static struct resource_spec am335x_dmtimer_irq_spec[] = {
99 	{ SYS_RES_IRQ,      0,  RF_ACTIVE },
100 	{ SYS_RES_IRQ,      1,  RF_ACTIVE },
101 	{ SYS_RES_IRQ,      2,  RF_ACTIVE },
102 	{ SYS_RES_IRQ,      3,  RF_ACTIVE },
103 	{ SYS_RES_IRQ,      4,  RF_ACTIVE },
104 	{ SYS_RES_IRQ,      5,  RF_ACTIVE },
105 	{ SYS_RES_IRQ,      6,  RF_ACTIVE },
106 	{ SYS_RES_IRQ,      7,  RF_ACTIVE },
107 	{ -1,               0,  0 }
108 };
109 
110 static struct am335x_dmtimer *am335x_dmtimer_tc_tmr = NULL;
111 
112 /* Read/Write macros for Timer used as timecounter */
113 #define am335x_dmtimer_tc_read_4(reg)		\
114 	bus_space_read_4(am335x_dmtimer_tc_tmr->bst, \
115 		am335x_dmtimer_tc_tmr->bsh, reg)
116 
117 #define am335x_dmtimer_tc_write_4(reg, val)	\
118 	bus_space_write_4(am335x_dmtimer_tc_tmr->bst, \
119 		am335x_dmtimer_tc_tmr->bsh, reg, val)
120 
121 /* Read/Write macros for Timer used as eventtimer */
122 #define am335x_dmtimer_et_read_4(reg)		\
123 	bus_space_read_4(tmr->bst, tmr->bsh, reg)
124 
125 #define am335x_dmtimer_et_write_4(reg, val)	\
126 	bus_space_write_4(tmr->bst, tmr->bsh, reg, val)
127 
128 static unsigned am335x_dmtimer_tc_get_timecount(struct timecounter *);
129 
130 static struct timecounter am335x_dmtimer_tc = {
131 	.tc_name           = "AM335x Timecounter",
132 	.tc_get_timecount  = am335x_dmtimer_tc_get_timecount,
133 	.tc_poll_pps       = NULL,
134 	.tc_counter_mask   = ~0u,
135 	.tc_frequency      = 0,
136 	.tc_quality        = 1000,
137 };
138 
139 static unsigned
140 am335x_dmtimer_tc_get_timecount(struct timecounter *tc)
141 {
142 	return am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
143 }
144 
145 static int
146 am335x_dmtimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
147 {
148 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)et->et_priv;
149 	uint32_t load, count;
150 	uint32_t tclr = 0;
151 
152 	if (period != 0) {
153 		load = ((uint32_t)et->et_frequency * period) >> 32;
154 		tclr |= 2; /* autoreload bit */
155 		panic("periodic timer not implemented\n");
156 	} else {
157 		load = 0;
158 	}
159 
160 	if (first != 0)
161 		count = ((uint32_t)et->et_frequency * first) >> 32;
162 	else
163 		count = load;
164 
165 	/* Reset Timer */
166 	am335x_dmtimer_et_write_4(DMTIMER_TSICR, 2);
167 
168 	/* Wait for reset to complete */
169 	while (am335x_dmtimer_et_read_4(DMTIMER_TIOCP_CFG) & 1);
170 
171 	/* set load value */
172 	am335x_dmtimer_et_write_4(DMTIMER_TLDR, 0xFFFFFFFE - load);
173 
174 	/* set counter value */
175 	am335x_dmtimer_et_write_4(DMTIMER_TCRR, 0xFFFFFFFE - count);
176 
177 	/* enable overflow interrupt */
178 	am335x_dmtimer_et_write_4(DMTIMER_IRQENABLE_SET, 2);
179 
180 	/* start timer(ST) */
181 	tclr |= 1;
182 	am335x_dmtimer_et_write_4(DMTIMER_TCLR, tclr);
183 
184 	return (0);
185 }
186 
187 static int
188 am335x_dmtimer_stop(struct eventtimer *et)
189 {
190 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)et->et_priv;
191 
192 	/* Disable all interrupts */
193 	am335x_dmtimer_et_write_4(DMTIMER_IRQENABLE_CLR, 7);
194 
195 	/* Stop Timer */
196 	am335x_dmtimer_et_write_4(DMTIMER_TCLR, 0);
197 
198 	return (0);
199 }
200 
201 static int
202 am335x_dmtimer_intr(void *arg)
203 {
204 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)arg;
205 
206 	/* Ack interrupt */
207 	am335x_dmtimer_et_write_4(DMTIMER_IRQSTATUS, 7);
208 	if (tmr->et.et_active)
209 		tmr->et.et_event_cb(&tmr->et, tmr->et.et_arg);
210 
211 	return (FILTER_HANDLED);
212 }
213 
214 static int
215 am335x_dmtimer_probe(device_t dev)
216 {
217 	struct	am335x_dmtimer_softc *sc;
218 	sc = (struct am335x_dmtimer_softc *)device_get_softc(dev);
219 
220 	if (ofw_bus_is_compatible(dev, "ti,am335x-dmtimer")) {
221 		device_set_desc(dev, "AM335x DMTimer");
222 		return(BUS_PROBE_DEFAULT);
223 	}
224 
225 	return (ENXIO);
226 }
227 
228 static int
229 am335x_dmtimer_attach(device_t dev)
230 {
231 	struct am335x_dmtimer_softc *sc = device_get_softc(dev);
232 	void *ihl;
233 	int err;
234 	int i;
235 
236 	if (am335x_dmtimer_tc_tmr != NULL)
237 		return (EINVAL);
238 
239 	/* Get the base clock frequency */
240 	err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq);
241 	if (err) {
242 		device_printf(dev, "Error: could not get sysclk frequency\n");
243 		return (ENXIO);
244 	}
245 
246 	/* Request the memory resources */
247 	err = bus_alloc_resources(dev, am335x_dmtimer_mem_spec,
248 		sc->tmr_mem_res);
249 	if (err) {
250 		device_printf(dev, "Error: could not allocate mem resources\n");
251 		return (ENXIO);
252 	}
253 
254 	/* Request the IRQ resources */
255 	err = bus_alloc_resources(dev, am335x_dmtimer_irq_spec,
256 		sc->tmr_irq_res);
257 	if (err) {
258 		device_printf(dev, "Error: could not allocate irq resources\n");
259 		return (ENXIO);
260 	}
261 
262 	for(i=0;i<AM335X_NUM_TIMERS;i++) {
263 		sc->t[i].bst = rman_get_bustag(sc->tmr_mem_res[i]);
264 		sc->t[i].bsh = rman_get_bushandle(sc->tmr_mem_res[i]);
265 	}
266 
267 	/* Configure DMTimer2 and DMTimer3 source and enable them */
268 	err  = ti_prcm_clk_set_source(DMTIMER2_CLK, SYSCLK_CLK);
269 	err |= ti_prcm_clk_enable(DMTIMER2_CLK);
270 	err |= ti_prcm_clk_set_source(DMTIMER3_CLK, SYSCLK_CLK);
271 	err |= ti_prcm_clk_enable(DMTIMER3_CLK);
272 	if (err) {
273 		device_printf(dev, "Error: could not setup timer clock\n");
274 		return (ENXIO);
275 	}
276 
277 	/* Take DMTimer2 for TC */
278 	am335x_dmtimer_tc_tmr = &sc->t[2];
279 
280 	/* Reset Timer */
281 	am335x_dmtimer_tc_write_4(DMTIMER_TSICR, 2);
282 
283 	/* Wait for reset to complete */
284 	while (am335x_dmtimer_tc_read_4(DMTIMER_TIOCP_CFG) & 1);
285 
286 	/* set load value */
287 	am335x_dmtimer_tc_write_4(DMTIMER_TLDR, 0);
288 
289 	/* set counter value */
290 	am335x_dmtimer_tc_write_4(DMTIMER_TCRR, 0);
291 
292 	/* Set Timer autoreload(AR) and start timer(ST) */
293 	am335x_dmtimer_tc_write_4(DMTIMER_TCLR, 3);
294 
295 	am335x_dmtimer_tc.tc_frequency = sc->sysclk_freq;
296 	tc_init(&am335x_dmtimer_tc);
297 
298 	/* Register DMTimer3 as ET */
299 
300 	/* Setup and enable the timer */
301 	if (bus_setup_intr(dev, sc->tmr_irq_res[3], INTR_TYPE_CLK,
302 			am335x_dmtimer_intr, NULL, &sc->t[3], &ihl) != 0) {
303 		bus_release_resources(dev, am335x_dmtimer_irq_spec,
304 			sc->tmr_irq_res);
305 		device_printf(dev, "Unable to setup the clock irq handler.\n");
306 		return (ENXIO);
307 	}
308 
309 	sc->t[3].et.et_name = "AM335x Eventtimer0";
310 	sc->t[3].et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
311 	sc->t[3].et.et_quality = 1000;
312 	sc->t[3].et.et_frequency = sc->sysclk_freq;
313 	sc->t[3].et.et_min_period =
314 	    (0x00000002LLU << 32) / sc->t[3].et.et_frequency;
315 	sc->t[3].et.et_max_period =
316 	    (0xfffffffeLLU << 32) / sc->t[3].et.et_frequency;
317 	sc->t[3].et.et_start = am335x_dmtimer_start;
318 	sc->t[3].et.et_stop = am335x_dmtimer_stop;
319 	sc->t[3].et.et_priv = &sc->t[3];
320 	et_register(&sc->t[3].et);
321 
322 	return (0);
323 }
324 
325 static device_method_t am335x_dmtimer_methods[] = {
326 	DEVMETHOD(device_probe,		am335x_dmtimer_probe),
327 	DEVMETHOD(device_attach,	am335x_dmtimer_attach),
328 	{ 0, 0 }
329 };
330 
331 static driver_t am335x_dmtimer_driver = {
332 	"am335x_dmtimer",
333 	am335x_dmtimer_methods,
334 	sizeof(struct am335x_dmtimer_softc),
335 };
336 
337 static devclass_t am335x_dmtimer_devclass;
338 
339 DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0);
340 MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1);
341 
342 void
343 cpu_initclocks(void)
344 {
345 	cpu_initclocks_bsp();
346 }
347 
348 void
349 DELAY(int usec)
350 {
351 		int32_t counts;
352 	uint32_t first, last;
353 
354 	if (am335x_dmtimer_tc_tmr == NULL) {
355 		for (; usec > 0; usec--)
356 			for (counts = 200; counts > 0; counts--)
357 				/* Prevent gcc from optimizing  out the loop */
358 				cpufunc_nullop();
359 		return;
360 	}
361 
362 	/* Get the number of times to count */
363 	counts = usec * ((am335x_dmtimer_tc.tc_frequency / 1000000) + 1);
364 
365 	first = am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
366 
367 	while (counts > 0) {
368 		last = am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
369 		if (last>first) {
370 			counts -= (int32_t)(last - first);
371 		} else {
372 			counts -= (int32_t)((0xFFFFFFFF - first) + last);
373 		}
374 		first = last;
375 	}
376 }
377 
378