xref: /freebsd/sys/riscv/sifive/sifive_prci.c (revision a90b9d0159070121c221b966469c3e36d912bf82)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019 Axiado Corporation
5  * All rights reserved.
6  * Copyright (c) 2021 Jessica Clarke <jrtc27@FreeBSD.org>
7  *
8  * This software was developed in part by Kristof Provost under contract for
9  * Axiado Corporation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/bus.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/rman.h>
41 
42 #include <machine/bus.h>
43 #include <machine/cpu.h>
44 
45 #include <dev/clk/clk.h>
46 #include <dev/clk/clk_fixed.h>
47 #include <dev/clk/clk_gate.h>
48 
49 #include <dev/ofw/ofw_bus.h>
50 #include <dev/ofw/ofw_bus_subr.h>
51 #include <dev/ofw/openfirm.h>
52 
53 #include "clkdev_if.h"
54 #include "hwreset_if.h"
55 
56 static struct resource_spec prci_spec[] = {
57 	{ SYS_RES_MEMORY, 0, RF_ACTIVE },
58 	RESOURCE_SPEC_END
59 };
60 
61 struct prci_softc {
62 	device_t		dev;
63 
64 	struct mtx		mtx;
65 
66 	struct clkdom		*clkdom;
67 	struct resource		*res;
68 	bus_space_tag_t		bst;
69 	bus_space_handle_t	bsh;
70 
71 	int			nresets;
72 };
73 
74 struct prci_clk_pll_sc {
75 	struct prci_softc	*parent_sc;
76 	uint32_t		reg;
77 };
78 
79 struct prci_clk_div_sc {
80 	struct prci_softc	*parent_sc;
81 	uint32_t		reg;
82 	uint32_t		bias;
83 };
84 
85 #define	PRCI_LOCK(sc)			mtx_lock(&(sc)->mtx)
86 #define	PRCI_UNLOCK(sc)			mtx_unlock(&(sc)->mtx)
87 #define	PRCI_ASSERT_LOCKED(sc)		mtx_assert(&(sc)->mtx, MA_OWNED);
88 #define	PRCI_ASSERT_UNLOCKED(sc)	mtx_assert(&(sc)->mtx, MA_NOTOWNED);
89 
90 #define	PRCI_PLL_DIVR_MASK		0x3f
91 #define	PRCI_PLL_DIVR_SHIFT		0
92 #define	PRCI_PLL_DIVF_MASK		0x7fc0
93 #define	PRCI_PLL_DIVF_SHIFT		6
94 #define	PRCI_PLL_DIVQ_MASK		0x38000
95 #define	PRCI_PLL_DIVQ_SHIFT		15
96 
97 /* Called devicesresetreg on the FU540 */
98 #define	PRCI_DEVICES_RESET_N		0x28
99 
100 #define	PRCI_READ(_sc, _reg)		\
101     bus_space_read_4((_sc)->bst, (_sc)->bsh, (_reg))
102 #define	PRCI_WRITE(_sc, _reg, _val)	\
103     bus_space_write_4((_sc)->bst, (_sc)->bsh, (_reg), (_val))
104 
105 struct prci_pll_def {
106 	uint32_t	id;
107 	const char	*name;
108 	uint32_t	reg;
109 };
110 
111 #define PLL(_id, _name, _base)					\
112 {								\
113 	.id = (_id),						\
114 	.name = (_name),					\
115 	.reg = (_base),						\
116 }
117 
118 #define PLL_END	PLL(0, NULL, 0)
119 
120 struct prci_div_def {
121 	uint32_t	id;
122 	const char	*name;
123 	const char	*parent_name;
124 	uint32_t	reg;
125 	uint32_t	bias;
126 };
127 
128 #define DIV(_id, _name, _parent_name, _base, _bias)		\
129 {								\
130 	.id = (_id),						\
131 	.name = (_name),					\
132 	.parent_name = (_parent_name),				\
133 	.reg = (_base),						\
134 	.bias = (_bias),					\
135 }
136 
137 #define DIV_END	DIV(0, NULL, NULL, 0, 0)
138 
139 struct prci_gate_def {
140 	uint32_t	id;
141 	const char	*name;
142 	const char	*parent_name;
143 	uint32_t	reg;
144 };
145 
146 #define GATE(_id, _name, _parent_name, _base)			\
147 {								\
148 	.id = (_id),						\
149 	.name = (_name),					\
150 	.parent_name = (_parent_name),				\
151 	.reg = (_base),						\
152 }
153 
154 #define GATE_END	GATE(0, NULL, NULL, 0)
155 
156 struct prci_config {
157 	struct prci_pll_def	*pll_clks;
158 	struct prci_div_def	*div_clks;
159 	struct prci_gate_def	*gate_clks;
160 	struct clk_fixed_def	*tlclk_def;
161 	int			nresets;
162 };
163 
164 /* FU540 clock numbers */
165 #define	FU540_PRCI_CORECLK		0
166 #define	FU540_PRCI_DDRCLK		1
167 #define	FU540_PRCI_GEMGXLCLK		2
168 #define	FU540_PRCI_TLCLK		3
169 
170 /* FU540 registers */
171 #define	FU540_PRCI_COREPLL_CFG0		0x4
172 #define	FU540_PRCI_DDRPLL_CFG0		0xC
173 #define	FU540_PRCI_GEMGXLPLL_CFG0	0x1C
174 
175 /* FU540 PLL clocks */
176 static struct prci_pll_def fu540_pll_clks[] = {
177 	PLL(FU540_PRCI_CORECLK, "coreclk", FU540_PRCI_COREPLL_CFG0),
178 	PLL(FU540_PRCI_DDRCLK, "ddrclk", FU540_PRCI_DDRPLL_CFG0),
179 	PLL(FU540_PRCI_GEMGXLCLK, "gemgxlclk", FU540_PRCI_GEMGXLPLL_CFG0),
180 	PLL_END
181 };
182 
183 /* FU540 fixed divisor clock TLCLK. */
184 static struct clk_fixed_def fu540_tlclk_def = {
185 	.clkdef.id = FU540_PRCI_TLCLK,
186 	.clkdef.name = "tlclk",
187 	.clkdef.parent_names = (const char *[]){"coreclk"},
188 	.clkdef.parent_cnt = 1,
189 	.clkdef.flags = CLK_NODE_STATIC_STRINGS,
190 	.mult = 1,
191 	.div = 2,
192 };
193 
194 /* FU540 config */
195 struct prci_config fu540_prci_config = {
196 	.pll_clks = fu540_pll_clks,
197 	.tlclk_def = &fu540_tlclk_def,
198 	.nresets = 6,
199 };
200 
201 /* FU740 clock numbers */
202 #define	FU740_PRCI_CORECLK		0
203 #define	FU740_PRCI_DDRCLK		1
204 #define	FU740_PRCI_GEMGXLCLK		2
205 #define	FU740_PRCI_DVFSCORECLK		3
206 #define	FU740_PRCI_HFPCLK		4
207 #define	FU740_PRCI_CLTXCLK		5
208 #define	FU740_PRCI_TLCLK		6
209 #define	FU740_PRCI_PCLK			7
210 #define	FU740_PRCI_PCIEAUXCLK		8
211 
212 /* FU740 registers */
213 #define	FU740_PRCI_COREPLL_CFG0		0x4
214 #define	FU740_PRCI_DDRPLL_CFG0		0xC
215 #define	FU740_PRCI_PCIEAUX_GATE		0x14
216 #define	FU740_PRCI_GEMGXLPLL_CFG0	0x1C
217 #define	FU740_PRCI_DVFSCOREPLL_CFG0	0x38
218 #define	FU740_PRCI_HFPCLKPLL_CFG0	0x50
219 #define	FU740_PRCI_CLTXPLL_CFG0		0x30
220 #define	FU740_PRCI_HFPCLK_DIV		0x5C
221 
222 /* FU740 PLL clocks */
223 static struct prci_pll_def fu740_pll_clks[] = {
224 	PLL(FU740_PRCI_CORECLK, "coreclk", FU740_PRCI_COREPLL_CFG0),
225 	PLL(FU740_PRCI_DDRCLK, "ddrclk", FU740_PRCI_DDRPLL_CFG0),
226 	PLL(FU740_PRCI_GEMGXLCLK, "gemgxlclk", FU740_PRCI_GEMGXLPLL_CFG0),
227 	PLL(FU740_PRCI_DVFSCORECLK, "dvfscoreclk", FU740_PRCI_DVFSCOREPLL_CFG0),
228 	PLL(FU740_PRCI_HFPCLK, "hfpclk", FU740_PRCI_HFPCLKPLL_CFG0),
229 	PLL(FU740_PRCI_CLTXCLK, "cltxclk", FU740_PRCI_CLTXPLL_CFG0),
230 	PLL_END
231 };
232 
233 /* FU740 divisor clocks */
234 static struct prci_div_def fu740_div_clks[] = {
235 	DIV(FU740_PRCI_PCLK, "pclk", "hfpclk", FU740_PRCI_HFPCLK_DIV, 2),
236 	DIV_END
237 };
238 
239 /* FU740 gated clocks */
240 static struct prci_gate_def fu740_gate_clks[] = {
241 	GATE(FU740_PRCI_PCIEAUXCLK, "pcieauxclk", "hfclk", FU740_PRCI_PCIEAUX_GATE),
242 	GATE_END
243 };
244 
245 /* FU740 fixed divisor clock TLCLK. */
246 static struct clk_fixed_def fu740_tlclk_def = {
247 	.clkdef.id = FU740_PRCI_TLCLK,
248 	.clkdef.name = "tlclk",
249 	.clkdef.parent_names = (const char *[]){"coreclk"},
250 	.clkdef.parent_cnt = 1,
251 	.clkdef.flags = CLK_NODE_STATIC_STRINGS,
252 	.mult = 1,
253 	.div = 2,
254 };
255 
256 /* FU740 config */
257 struct prci_config fu740_prci_config = {
258 	.pll_clks = fu740_pll_clks,
259 	.div_clks = fu740_div_clks,
260 	.gate_clks = fu740_gate_clks,
261 	.tlclk_def = &fu740_tlclk_def,
262 	.nresets = 7,
263 };
264 
265 static struct ofw_compat_data compat_data[] = {
266 	{ "sifive,aloeprci0",		(uintptr_t)&fu540_prci_config },
267 	{ "sifive,ux00prci0",		(uintptr_t)&fu540_prci_config },
268 	{ "sifive,fu540-c000-prci",	(uintptr_t)&fu540_prci_config },
269 	{ "sifive,fu740-c000-prci",	(uintptr_t)&fu740_prci_config },
270 	{ NULL,				0 },
271 };
272 
273 static int
274 prci_clk_pll_init(struct clknode *clk, device_t dev)
275 {
276 
277 	clknode_init_parent_idx(clk, 0);
278 
279 	return (0);
280 }
281 
282 static int
283 prci_clk_pll_recalc(struct clknode *clk, uint64_t *freq)
284 {
285 	struct prci_clk_pll_sc *sc;
286 	struct clknode *parent_clk;
287 	uint32_t val;
288 	uint64_t refclk, divf, divq, divr;
289 	int err;
290 
291 	KASSERT(freq != NULL, ("freq cannot be NULL"));
292 
293 	sc = clknode_get_softc(clk);
294 
295 	PRCI_LOCK(sc->parent_sc);
296 
297 	/* Get refclock frequency. */
298 	parent_clk = clknode_get_parent(clk);
299 	err = clknode_get_freq(parent_clk, &refclk);
300 	if (err) {
301 		device_printf(sc->parent_sc->dev,
302 		    "Failed to get refclk frequency\n");
303 		PRCI_UNLOCK(sc->parent_sc);
304 		return (err);
305 	}
306 
307 	/* Calculate the PLL output */
308 	val = PRCI_READ(sc->parent_sc, sc->reg);
309 
310 	divf = (val & PRCI_PLL_DIVF_MASK) >> PRCI_PLL_DIVF_SHIFT;
311 	divq = (val & PRCI_PLL_DIVQ_MASK) >> PRCI_PLL_DIVQ_SHIFT;
312 	divr = (val & PRCI_PLL_DIVR_MASK) >> PRCI_PLL_DIVR_SHIFT;
313 
314 	*freq = refclk / (divr + 1) * (2 * (divf + 1)) / (1 << divq);
315 
316 	PRCI_UNLOCK(sc->parent_sc);
317 
318 	return (0);
319 }
320 
321 static clknode_method_t prci_clk_pll_clknode_methods[] = {
322 	CLKNODEMETHOD(clknode_init,		prci_clk_pll_init),
323 	CLKNODEMETHOD(clknode_recalc_freq,	prci_clk_pll_recalc),
324 	CLKNODEMETHOD_END
325 };
326 
327 DEFINE_CLASS_1(prci_clk_pll_clknode, prci_clk_pll_clknode_class,
328     prci_clk_pll_clknode_methods, sizeof(struct prci_clk_pll_sc),
329     clknode_class);
330 
331 static int
332 prci_clk_div_init(struct clknode *clk, device_t dev)
333 {
334 
335 	clknode_init_parent_idx(clk, 0);
336 
337 	return (0);
338 }
339 
340 static int
341 prci_clk_div_recalc(struct clknode *clk, uint64_t *freq)
342 {
343 	struct prci_clk_div_sc *sc;
344 	struct clknode *parent_clk;
345 	uint32_t div;
346 	uint64_t refclk;
347 	int err;
348 
349 	KASSERT(freq != NULL, ("freq cannot be NULL"));
350 
351 	sc = clknode_get_softc(clk);
352 
353 	PRCI_LOCK(sc->parent_sc);
354 
355 	/* Get refclock frequency. */
356 	parent_clk = clknode_get_parent(clk);
357 	err = clknode_get_freq(parent_clk, &refclk);
358 	if (err) {
359 		device_printf(sc->parent_sc->dev,
360 		    "Failed to get refclk frequency\n");
361 		PRCI_UNLOCK(sc->parent_sc);
362 		return (err);
363 	}
364 
365 	/* Calculate the divisor output */
366 	div = PRCI_READ(sc->parent_sc, sc->reg);
367 
368 	*freq = refclk / (div + sc->bias);
369 
370 	PRCI_UNLOCK(sc->parent_sc);
371 
372 	return (0);
373 }
374 
375 static clknode_method_t prci_clk_div_clknode_methods[] = {
376 	CLKNODEMETHOD(clknode_init,		prci_clk_div_init),
377 	CLKNODEMETHOD(clknode_recalc_freq,	prci_clk_div_recalc),
378 	CLKNODEMETHOD_END
379 };
380 
381 DEFINE_CLASS_1(prci_clk_div_clknode, prci_clk_div_clknode_class,
382     prci_clk_div_clknode_methods, sizeof(struct prci_clk_div_sc),
383     clknode_class);
384 
385 static int
386 prci_probe(device_t dev)
387 {
388 
389 	if (!ofw_bus_status_okay(dev))
390 		return (ENXIO);
391 
392 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
393 		return (ENXIO);
394 
395 	device_set_desc(dev, "SiFive Power Reset Clocking Interrupt");
396 
397 	return (BUS_PROBE_DEFAULT);
398 }
399 
400 static void
401 prci_pll_register(struct prci_softc *parent_sc, struct clknode_init_def *clkdef,
402 	uint32_t reg)
403 {
404 	struct clknode *clk;
405 	struct prci_clk_pll_sc *sc;
406 
407 	clk = clknode_create(parent_sc->clkdom, &prci_clk_pll_clknode_class,
408 	    clkdef);
409 	if (clk == NULL)
410 		panic("Failed to create clknode");
411 
412 	sc = clknode_get_softc(clk);
413 	sc->parent_sc = parent_sc;
414 	sc->reg = reg;
415 
416 	clknode_register(parent_sc->clkdom, clk);
417 }
418 
419 static void
420 prci_div_register(struct prci_softc *parent_sc, struct clknode_init_def *clkdef,
421 	uint32_t reg, uint32_t bias)
422 {
423 	struct clknode *clk;
424 	struct prci_clk_div_sc *sc;
425 
426 	clk = clknode_create(parent_sc->clkdom, &prci_clk_div_clknode_class,
427 	    clkdef);
428 	if (clk == NULL)
429 		panic("Failed to create clknode");
430 
431 	sc = clknode_get_softc(clk);
432 	sc->parent_sc = parent_sc;
433 	sc->reg = reg;
434 	sc->bias = bias;
435 
436 	clknode_register(parent_sc->clkdom, clk);
437 }
438 
439 static int
440 prci_attach(device_t dev)
441 {
442 	struct clknode_init_def clkdef, clkdef_div;
443 	struct clk_gate_def clkdef_gate;
444 	struct prci_softc *sc;
445 	clk_t clk_parent;
446 	phandle_t node;
447 	int i, ncells, error;
448 	struct prci_config *cfg;
449 	struct prci_pll_def *pll_clk;
450 	struct prci_div_def *div_clk;
451 	struct prci_gate_def *gate_clk;
452 
453 	sc = device_get_softc(dev);
454 	sc->dev = dev;
455 
456 	cfg = (struct prci_config *)ofw_bus_search_compatible(dev,
457 	    compat_data)->ocd_data;
458 
459 	mtx_init(&sc->mtx, device_get_nameunit(sc->dev), NULL, MTX_DEF);
460 
461 	error = bus_alloc_resources(dev, prci_spec, &sc->res);
462 	if (error) {
463 		device_printf(dev, "Couldn't allocate resources\n");
464 		goto fail;
465 	}
466 	sc->bst = rman_get_bustag(sc->res);
467 	sc->bsh = rman_get_bushandle(sc->res);
468 
469 	node = ofw_bus_get_node(dev);
470 	error = ofw_bus_parse_xref_list_get_length(node, "clocks",
471 	    "#clock-cells", &ncells);
472 	if (error != 0 || ncells < 1) {
473 		device_printf(dev, "couldn't find parent clock\n");
474 		goto fail;
475 	}
476 
477 	bzero(&clkdef, sizeof(clkdef));
478 	clkdef.parent_names = mallocarray(ncells, sizeof(char *), M_OFWPROP,
479 	    M_WAITOK);
480 	for (i = 0; i < ncells; i++) {
481 		error = clk_get_by_ofw_index(dev, 0, i, &clk_parent);
482 		if (error != 0) {
483 			device_printf(dev, "cannot get clock %d\n", error);
484 			goto fail1;
485 		}
486 		clkdef.parent_names[i] = clk_get_name(clk_parent);
487 		if (bootverbose)
488 			device_printf(dev, "clk parent: %s\n",
489 			    clkdef.parent_names[i]);
490 		clk_release(clk_parent);
491 	}
492 	clkdef.parent_cnt = ncells;
493 
494 	sc->clkdom = clkdom_create(dev);
495 	if (sc->clkdom == NULL) {
496 		device_printf(dev, "Couldn't create clock domain\n");
497 		goto fail;
498 	}
499 
500 	/* We can't free a clkdom, so from now on we cannot fail. */
501 	for (pll_clk = cfg->pll_clks; pll_clk->name; pll_clk++) {
502 		clkdef.id = pll_clk->id;
503 		clkdef.name = pll_clk->name;
504 		prci_pll_register(sc, &clkdef, pll_clk->reg);
505 	}
506 
507 	if (cfg->div_clks != NULL) {
508 		bzero(&clkdef_div, sizeof(clkdef_div));
509 		for (div_clk = cfg->div_clks; div_clk->name; div_clk++) {
510 			clkdef_div.id = div_clk->id;
511 			clkdef_div.name = div_clk->name;
512 			clkdef_div.parent_names = &div_clk->parent_name;
513 			clkdef_div.parent_cnt = 1;
514 			prci_div_register(sc, &clkdef_div, div_clk->reg,
515 			    div_clk->bias);
516 		}
517 	}
518 
519 	if (cfg->gate_clks != NULL) {
520 		bzero(&clkdef_gate, sizeof(clkdef_gate));
521 		for (gate_clk = cfg->gate_clks; gate_clk->name; gate_clk++) {
522 			clkdef_gate.clkdef.id = gate_clk->id;
523 			clkdef_gate.clkdef.name = gate_clk->name;
524 			clkdef_gate.clkdef.parent_names = &gate_clk->parent_name;
525 			clkdef_gate.clkdef.parent_cnt = 1;
526 			clkdef_gate.offset = gate_clk->reg;
527 			clkdef_gate.shift = 0;
528 			clkdef_gate.mask = 1;
529 			clkdef_gate.on_value = 1;
530 			clkdef_gate.off_value = 0;
531 			error = clknode_gate_register(sc->clkdom,
532 			    &clkdef_gate);
533 			if (error != 0) {
534 				device_printf(dev,
535 				    "Couldn't create gated clock %s: %d\n",
536 				    gate_clk->name, error);
537 				goto fail;
538 			}
539 		}
540 	}
541 
542 	/*
543 	 * Register the fixed clock "tlclk".
544 	 *
545 	 * If an older device tree is being used, tlclk may appear as its own
546 	 * entity in the device tree, under soc/tlclk. If this is the case it
547 	 * will be registered automatically by the fixed_clk driver, and the
548 	 * version we register here will be an unreferenced duplicate.
549 	 */
550 	clknode_fixed_register(sc->clkdom, cfg->tlclk_def);
551 
552 	error = clkdom_finit(sc->clkdom);
553 	if (error)
554 		panic("Couldn't finalise clock domain");
555 
556 	sc->nresets = cfg->nresets;
557 
558 	return (0);
559 
560 fail1:
561 	free(clkdef.parent_names, M_OFWPROP);
562 
563 fail:
564 	bus_release_resources(dev, prci_spec, &sc->res);
565 	mtx_destroy(&sc->mtx);
566 	return (error);
567 }
568 
569 static int
570 prci_write_4(device_t dev, bus_addr_t addr, uint32_t val)
571 {
572 	struct prci_softc *sc;
573 
574 	sc = device_get_softc(dev);
575 
576 	PRCI_WRITE(sc, addr, val);
577 
578 	return (0);
579 }
580 
581 static int
582 prci_read_4(device_t dev, bus_addr_t addr, uint32_t *val)
583 {
584 	struct prci_softc *sc;
585 
586 	sc = device_get_softc(dev);
587 
588 	*val = PRCI_READ(sc, addr);
589 
590 	return (0);
591 }
592 
593 static int
594 prci_modify_4(device_t dev, bus_addr_t addr, uint32_t clr, uint32_t set)
595 {
596 	struct prci_softc *sc;
597 	uint32_t reg;
598 
599 	sc = device_get_softc(dev);
600 
601 	reg = PRCI_READ(sc, addr);
602 	reg &= ~clr;
603 	reg |= set;
604 	PRCI_WRITE(sc, addr, reg);
605 
606 	return (0);
607 }
608 
609 static void
610 prci_device_lock(device_t dev)
611 {
612 	struct prci_softc *sc;
613 
614 	sc = device_get_softc(dev);
615 	PRCI_LOCK(sc);
616 }
617 
618 static void
619 prci_device_unlock(device_t dev)
620 {
621 	struct prci_softc *sc;
622 
623 	sc = device_get_softc(dev);
624 	PRCI_UNLOCK(sc);
625 }
626 
627 static int
628 prci_reset_assert(device_t dev, intptr_t id, bool reset)
629 {
630 	struct prci_softc *sc;
631 	uint32_t reg;
632 
633 	sc = device_get_softc(dev);
634 
635 	if (id >= sc->nresets)
636 		return (ENXIO);
637 
638 	PRCI_LOCK(sc);
639 	reg = PRCI_READ(sc, PRCI_DEVICES_RESET_N);
640 	if (reset)
641 		reg &= ~(1u << id);
642 	else
643 		reg |= (1u << id);
644 	PRCI_WRITE(sc, PRCI_DEVICES_RESET_N, reg);
645 	PRCI_UNLOCK(sc);
646 
647 	return (0);
648 }
649 
650 static int
651 prci_reset_is_asserted(device_t dev, intptr_t id, bool *reset)
652 {
653 	struct prci_softc *sc;
654 	uint32_t reg;
655 
656 	sc = device_get_softc(dev);
657 
658 	if (id >= sc->nresets)
659 		return (ENXIO);
660 
661 	PRCI_LOCK(sc);
662 	reg = PRCI_READ(sc, PRCI_DEVICES_RESET_N);
663 	*reset = (reg & (1u << id)) == 0;
664 	PRCI_UNLOCK(sc);
665 
666 	return (0);
667 }
668 
669 static device_method_t prci_methods[] = {
670 	DEVMETHOD(device_probe,		prci_probe),
671 	DEVMETHOD(device_attach,	prci_attach),
672 
673 	/* clkdev interface */
674 	DEVMETHOD(clkdev_write_4,	prci_write_4),
675 	DEVMETHOD(clkdev_read_4,	prci_read_4),
676 	DEVMETHOD(clkdev_modify_4,	prci_modify_4),
677 	DEVMETHOD(clkdev_device_lock,	prci_device_lock),
678 	DEVMETHOD(clkdev_device_unlock,	prci_device_unlock),
679 
680 	/* Reset interface */
681 	DEVMETHOD(hwreset_assert,	prci_reset_assert),
682 	DEVMETHOD(hwreset_is_asserted,	prci_reset_is_asserted),
683 
684 	DEVMETHOD_END
685 };
686 
687 static driver_t prci_driver = {
688 	"sifive_prci",
689 	prci_methods,
690 	sizeof(struct prci_softc)
691 };
692 
693 /*
694  * hfclk and rtcclk appear later in the device tree than prci, so we must
695  * attach late.
696  */
697 EARLY_DRIVER_MODULE(sifive_prci, simplebus, prci_driver, 0, 0,
698     BUS_PASS_BUS + BUS_PASS_ORDER_LATE);
699