xref: /freebsd/sys/arm/ti/am335x/am335x_dmtimer.c (revision 84dfba8d183d31e3412639ecb4b8ad4433cf7e80)
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/intr.h>
43 
44 #include <dev/fdt/fdt_common.h>
45 #include <dev/ofw/openfirm.h>
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include <machine/bus.h>
50 #include <machine/fdt.h>
51 
52 #include <arm/ti/ti_prcm.h>
53 
54 #define AM335X_NUM_TIMERS	8
55 
56 #define DMTIMER_TIDR		0x00 /* Identification Register */
57 #define DMTIMER_TIOCP_CFG	0x10 /* Timer OCP Configuration Reg */
58 #define DMTIMER_IQR_EOI		0x20 /* Timer IRQ End-Of-Interrupt Reg */
59 #define DMTIMER_IRQSTATUS_RAW	0x24 /* Timer IRQSTATUS Raw Reg */
60 #define DMTIMER_IRQSTATUS	0x28 /* Timer IRQSTATUS Reg */
61 #define DMTIMER_IRQENABLE_SET	0x2c /* Timer IRQSTATUS Set Reg */
62 #define DMTIMER_IRQENABLE_CLR	0x30 /* Timer IRQSTATUS Clear Reg */
63 #define DMTIMER_IRQWAKEEN	0x34 /* Timer IRQ Wakeup Enable Reg */
64 #define DMTIMER_TCLR		0x38 /* Timer Control Register */
65 #define DMTIMER_TCRR		0x3C /* Timer Counter Register */
66 #define DMTIMER_TLDR		0x40 /* Timer Load Reg */
67 #define DMTIMER_TTGR		0x44 /* Timer Trigger Reg */
68 #define DMTIMER_TWPS		0x48 /* Timer Write Posted Status Reg */
69 #define DMTIMER_TMAR		0x4C /* Timer Match Reg */
70 #define DMTIMER_TCAR1		0x50 /* Timer Capture Reg */
71 #define DMTIMER_TSICR		0x54 /* Timer Synchr. Interface Control Reg */
72 #define DMTIMER_TCAR2		0x48 /* Timer Capture Reg */
73 
74 
75 struct am335x_dmtimer_softc {
76 	struct resource *	tmr_mem_res[AM335X_NUM_TIMERS];
77 	struct resource *	tmr_irq_res[AM335X_NUM_TIMERS];
78 	uint32_t		sysclk_freq;
79 	struct am335x_dmtimer {
80 		bus_space_tag_t		bst;
81 		bus_space_handle_t	bsh;
82 		struct eventtimer	et;
83 	} t[AM335X_NUM_TIMERS];
84 };
85 
86 static struct resource_spec am335x_dmtimer_mem_spec[] = {
87 	{ SYS_RES_MEMORY,   0,  RF_ACTIVE },
88 	{ SYS_RES_MEMORY,   1,  RF_ACTIVE },
89 	{ SYS_RES_MEMORY,   2,  RF_ACTIVE },
90 	{ SYS_RES_MEMORY,   3,  RF_ACTIVE },
91 	{ SYS_RES_MEMORY,   4,  RF_ACTIVE },
92 	{ SYS_RES_MEMORY,   5,  RF_ACTIVE },
93 	{ SYS_RES_MEMORY,   6,  RF_ACTIVE },
94 	{ SYS_RES_MEMORY,   7,  RF_ACTIVE },
95 	{ -1,               0,  0 }
96 };
97 static struct resource_spec am335x_dmtimer_irq_spec[] = {
98 	{ SYS_RES_IRQ,      0,  RF_ACTIVE },
99 	{ SYS_RES_IRQ,      1,  RF_ACTIVE },
100 	{ SYS_RES_IRQ,      2,  RF_ACTIVE },
101 	{ SYS_RES_IRQ,      3,  RF_ACTIVE },
102 	{ SYS_RES_IRQ,      4,  RF_ACTIVE },
103 	{ SYS_RES_IRQ,      5,  RF_ACTIVE },
104 	{ SYS_RES_IRQ,      6,  RF_ACTIVE },
105 	{ SYS_RES_IRQ,      7,  RF_ACTIVE },
106 	{ -1,               0,  0 }
107 };
108 
109 static struct am335x_dmtimer *am335x_dmtimer_tc_tmr = NULL;
110 
111 /* Read/Write macros for Timer used as timecounter */
112 #define am335x_dmtimer_tc_read_4(reg)		\
113 	bus_space_read_4(am335x_dmtimer_tc_tmr->bst, \
114 		am335x_dmtimer_tc_tmr->bsh, reg)
115 
116 #define am335x_dmtimer_tc_write_4(reg, val)	\
117 	bus_space_write_4(am335x_dmtimer_tc_tmr->bst, \
118 		am335x_dmtimer_tc_tmr->bsh, reg, val)
119 
120 /* Read/Write macros for Timer used as eventtimer */
121 #define am335x_dmtimer_et_read_4(reg)		\
122 	bus_space_read_4(tmr->bst, tmr->bsh, reg)
123 
124 #define am335x_dmtimer_et_write_4(reg, val)	\
125 	bus_space_write_4(tmr->bst, tmr->bsh, reg, val)
126 
127 static unsigned am335x_dmtimer_tc_get_timecount(struct timecounter *);
128 
129 static struct timecounter am335x_dmtimer_tc = {
130 	.tc_name           = "AM335x Timecounter",
131 	.tc_get_timecount  = am335x_dmtimer_tc_get_timecount,
132 	.tc_poll_pps       = NULL,
133 	.tc_counter_mask   = ~0u,
134 	.tc_frequency      = 0,
135 	.tc_quality        = 1000,
136 };
137 
138 static unsigned
139 am335x_dmtimer_tc_get_timecount(struct timecounter *tc)
140 {
141 	return am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
142 }
143 
144 static int
145 am335x_dmtimer_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
146 {
147 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)et->et_priv;
148 	uint32_t load, count;
149 	uint32_t tclr = 0;
150 
151 	if (period != 0) {
152 		load = ((uint32_t)et->et_frequency * period) >> 32;
153 		tclr |= 2; /* autoreload bit */
154 		panic("periodic timer not implemented\n");
155 	} else {
156 		load = 0;
157 	}
158 
159 	if (first != 0)
160 		count = ((uint32_t)et->et_frequency * first) >> 32;
161 	else
162 		count = load;
163 
164 	/* Reset Timer */
165 	am335x_dmtimer_et_write_4(DMTIMER_TSICR, 2);
166 
167 	/* Wait for reset to complete */
168 	while (am335x_dmtimer_et_read_4(DMTIMER_TIOCP_CFG) & 1);
169 
170 	/* set load value */
171 	am335x_dmtimer_et_write_4(DMTIMER_TLDR, 0xFFFFFFFE - load);
172 
173 	/* set counter value */
174 	am335x_dmtimer_et_write_4(DMTIMER_TCRR, 0xFFFFFFFE - count);
175 
176 	/* enable overflow interrupt */
177 	am335x_dmtimer_et_write_4(DMTIMER_IRQENABLE_SET, 2);
178 
179 	/* start timer(ST) */
180 	tclr |= 1;
181 	am335x_dmtimer_et_write_4(DMTIMER_TCLR, tclr);
182 
183 	return (0);
184 }
185 
186 static int
187 am335x_dmtimer_stop(struct eventtimer *et)
188 {
189 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)et->et_priv;
190 
191 	/* Disable all interrupts */
192 	am335x_dmtimer_et_write_4(DMTIMER_IRQENABLE_CLR, 7);
193 
194 	/* Stop Timer */
195 	am335x_dmtimer_et_write_4(DMTIMER_TCLR, 0);
196 
197 	return (0);
198 }
199 
200 static int
201 am335x_dmtimer_intr(void *arg)
202 {
203 	struct am335x_dmtimer *tmr = (struct am335x_dmtimer *)arg;
204 
205 	/* Ack interrupt */
206 	am335x_dmtimer_et_write_4(DMTIMER_IRQSTATUS, 7);
207 	if (tmr->et.et_active)
208 		tmr->et.et_event_cb(&tmr->et, tmr->et.et_arg);
209 
210 	return (FILTER_HANDLED);
211 }
212 
213 static int
214 am335x_dmtimer_probe(device_t dev)
215 {
216 	struct	am335x_dmtimer_softc *sc;
217 	sc = (struct am335x_dmtimer_softc *)device_get_softc(dev);
218 
219 	if (ofw_bus_is_compatible(dev, "ti,am335x-dmtimer")) {
220 		device_set_desc(dev, "AM335x DMTimer");
221 		return(BUS_PROBE_DEFAULT);
222 	}
223 
224 	return (ENXIO);
225 }
226 
227 static int
228 am335x_dmtimer_attach(device_t dev)
229 {
230 	struct am335x_dmtimer_softc *sc = device_get_softc(dev);
231 	void *ihl;
232 	int err;
233 	int i;
234 
235 	if (am335x_dmtimer_tc_tmr != NULL)
236 		return (EINVAL);
237 
238 	/* Get the base clock frequency */
239 	err = ti_prcm_clk_get_source_freq(SYS_CLK, &sc->sysclk_freq);
240 	if (err) {
241 		device_printf(dev, "Error: could not get sysclk frequency\n");
242 		return (ENXIO);
243 	}
244 
245 	/* Request the memory resources */
246 	err = bus_alloc_resources(dev, am335x_dmtimer_mem_spec,
247 		sc->tmr_mem_res);
248 	if (err) {
249 		device_printf(dev, "Error: could not allocate mem resources\n");
250 		return (ENXIO);
251 	}
252 
253 	/* Request the IRQ resources */
254 	err = bus_alloc_resources(dev, am335x_dmtimer_irq_spec,
255 		sc->tmr_irq_res);
256 	if (err) {
257 		device_printf(dev, "Error: could not allocate irq resources\n");
258 		return (ENXIO);
259 	}
260 
261 	for(i=0;i<AM335X_NUM_TIMERS;i++) {
262 		sc->t[i].bst = rman_get_bustag(sc->tmr_mem_res[i]);
263 		sc->t[i].bsh = rman_get_bushandle(sc->tmr_mem_res[i]);
264 	}
265 
266 	/* Configure DMTimer2 and DMTimer3 source and enable them */
267 	err  = ti_prcm_clk_set_source(DMTIMER2_CLK, SYSCLK_CLK);
268 	err |= ti_prcm_clk_enable(DMTIMER2_CLK);
269 	err |= ti_prcm_clk_set_source(DMTIMER3_CLK, SYSCLK_CLK);
270 	err |= ti_prcm_clk_enable(DMTIMER3_CLK);
271 	if (err) {
272 		device_printf(dev, "Error: could not setup timer clock\n");
273 		return (ENXIO);
274 	}
275 
276 	/* Take DMTimer2 for TC */
277 	am335x_dmtimer_tc_tmr = &sc->t[2];
278 
279 	/* Reset Timer */
280 	am335x_dmtimer_tc_write_4(DMTIMER_TSICR, 2);
281 
282 	/* Wait for reset to complete */
283 	while (am335x_dmtimer_tc_read_4(DMTIMER_TIOCP_CFG) & 1);
284 
285 	/* set load value */
286 	am335x_dmtimer_tc_write_4(DMTIMER_TLDR, 0);
287 
288 	/* set counter value */
289 	am335x_dmtimer_tc_write_4(DMTIMER_TCRR, 0);
290 
291 	/* Set Timer autoreload(AR) and start timer(ST) */
292 	am335x_dmtimer_tc_write_4(DMTIMER_TCLR, 3);
293 
294 	am335x_dmtimer_tc.tc_frequency = sc->sysclk_freq;
295 	tc_init(&am335x_dmtimer_tc);
296 
297 	/* Register DMTimer3 as ET */
298 
299 	/* Setup and enable the timer */
300 	if (bus_setup_intr(dev, sc->tmr_irq_res[3], INTR_TYPE_CLK,
301 			am335x_dmtimer_intr, NULL, &sc->t[3], &ihl) != 0) {
302 		bus_release_resources(dev, am335x_dmtimer_irq_spec,
303 			sc->tmr_irq_res);
304 		device_printf(dev, "Unable to setup the clock irq handler.\n");
305 		return (ENXIO);
306 	}
307 
308 	sc->t[3].et.et_name = "AM335x Eventtimer0";
309 	sc->t[3].et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT;
310 	sc->t[3].et.et_quality = 1000;
311 	sc->t[3].et.et_frequency = sc->sysclk_freq;
312 	sc->t[3].et.et_min_period =
313 	    (0x00000002LLU << 32) / sc->t[3].et.et_frequency;
314 	sc->t[3].et.et_max_period =
315 	    (0xfffffffeLLU << 32) / sc->t[3].et.et_frequency;
316 	sc->t[3].et.et_start = am335x_dmtimer_start;
317 	sc->t[3].et.et_stop = am335x_dmtimer_stop;
318 	sc->t[3].et.et_priv = &sc->t[3];
319 	et_register(&sc->t[3].et);
320 
321 	return (0);
322 }
323 
324 static device_method_t am335x_dmtimer_methods[] = {
325 	DEVMETHOD(device_probe,		am335x_dmtimer_probe),
326 	DEVMETHOD(device_attach,	am335x_dmtimer_attach),
327 	{ 0, 0 }
328 };
329 
330 static driver_t am335x_dmtimer_driver = {
331 	"am335x_dmtimer",
332 	am335x_dmtimer_methods,
333 	sizeof(struct am335x_dmtimer_softc),
334 };
335 
336 static devclass_t am335x_dmtimer_devclass;
337 
338 DRIVER_MODULE(am335x_dmtimer, simplebus, am335x_dmtimer_driver, am335x_dmtimer_devclass, 0, 0);
339 MODULE_DEPEND(am335x_dmtimer, am335x_prcm, 1, 1, 1);
340 
341 void
342 cpu_initclocks(void)
343 {
344 	cpu_initclocks_bsp();
345 }
346 
347 void
348 DELAY(int usec)
349 {
350 		int32_t counts;
351 	uint32_t first, last;
352 
353 	if (am335x_dmtimer_tc_tmr == NULL) {
354 		for (; usec > 0; usec--)
355 			for (counts = 200; counts > 0; counts--)
356 				/* Prevent gcc from optimizing  out the loop */
357 				cpufunc_nullop();
358 		return;
359 	}
360 
361 	/* Get the number of times to count */
362 	counts = usec * ((am335x_dmtimer_tc.tc_frequency / 1000000) + 1);
363 
364 	first = am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
365 
366 	while (counts > 0) {
367 		last = am335x_dmtimer_tc_read_4(DMTIMER_TCRR);
368 		if (last>first) {
369 			counts -= (int32_t)(last - first);
370 		} else {
371 			counts -= (int32_t)((0xFFFFFFFF - first) + last);
372 		}
373 		first = last;
374 	}
375 }
376 
377