xref: /freebsd/sys/dev/firmware/arm/scmi_clk.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Ruslan Bukin <br@bsdpad.com>
5  *
6  * This work was supported by Innovate UK project 105694, "Digital Security
7  * by Design (DSbD) Technology Platform Prototype".
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/cpu.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 
38 #include <dev/clk/clk.h>
39 #include <dev/fdt/simplebus.h>
40 #include <dev/fdt/fdt_common.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include "scmi.h"
44 #include "scmi_protocols.h"
45 #include "scmi_clk.h"
46 
47 struct scmi_clk_softc {
48 	device_t	dev;
49 	device_t	scmi;
50 	struct clkdom	*clkdom;
51 };
52 
53 struct scmi_clknode_softc {
54 	device_t	dev;
55 	int		clock_id;
56 };
57 
58 static int __unused
59 scmi_clk_get_rate(struct scmi_clk_softc *sc, int clk_id, uint64_t *rate)
60 {
61 	struct scmi_clk_rate_get_out out;
62 	struct scmi_clk_rate_get_in in;
63 	struct scmi_req req;
64 	int error;
65 
66 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
67 	req.message_id = SCMI_CLOCK_RATE_GET;
68 	req.in_buf = &in;
69 	req.in_size = sizeof(struct scmi_clk_rate_get_in);
70 	req.out_buf = &out;
71 	req.out_size = sizeof(struct scmi_clk_rate_get_out);
72 
73 	in.clock_id = clk_id;
74 
75 	error = scmi_request(sc->scmi, &req);
76 	if (error != 0)
77 		return (error);
78 
79 	if (out.status != 0)
80 		return (ENXIO);
81 
82 	*rate = out.rate_lsb | ((uint64_t)out.rate_msb << 32);
83 
84 	return (0);
85 }
86 
87 static int
88 scmi_clk_set_rate(struct scmi_clk_softc *sc, int clk_id, uint64_t rate)
89 {
90 	struct scmi_clk_rate_set_out out;
91 	struct scmi_clk_rate_set_in in;
92 	struct scmi_req req;
93 	int error;
94 
95 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
96 	req.message_id = SCMI_CLOCK_RATE_SET;
97 	req.in_buf = &in;
98 	req.in_size = sizeof(struct scmi_clk_rate_set_in);
99 	req.out_buf = &out;
100 	req.out_size = sizeof(struct scmi_clk_rate_set_out);
101 
102 	in.clock_id = clk_id;
103 	in.flags = SCMI_CLK_RATE_ROUND_CLOSEST;
104 	in.rate_lsb = (uint32_t)rate;
105 	in.rate_msb = (uint32_t)(rate >> 32);
106 
107 	error = scmi_request(sc->scmi, &req);
108 	if (error != 0)
109 		return (error);
110 
111 	if (out.status != 0)
112 		return (ENXIO);
113 
114 	return (0);
115 }
116 
117 static int __unused
118 scmi_clk_gate(struct scmi_clk_softc *sc, int clk_id, int enable)
119 {
120 	struct scmi_clk_state_out out;
121 	struct scmi_clk_state_in in;
122 	struct scmi_req req;
123 	int error;
124 
125 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
126 	req.message_id = SCMI_CLOCK_CONFIG_SET;
127 	req.in_buf = &in;
128 	req.in_size = sizeof(struct scmi_clk_state_in);
129 	req.out_buf = &out;
130 	req.out_size = sizeof(struct scmi_clk_state_out);
131 
132 	in.clock_id = clk_id;
133 	in.attributes = enable;
134 
135 	error = scmi_request(sc->scmi, &req);
136 	if (error != 0)
137 		return (error);
138 
139 	if (out.status != 0)
140 		return (ENXIO);
141 
142 	return (0);
143 }
144 
145 static int
146 scmi_clknode_init(struct clknode *clk, device_t dev)
147 {
148 
149 	clknode_init_parent_idx(clk, 0);
150 
151 	return (0);
152 }
153 
154 static int
155 scmi_clknode_recalc_freq(struct clknode *clk, uint64_t *freq)
156 {
157 
158 	return (0);
159 }
160 
161 static int
162 scmi_clknode_set_freq(struct clknode *clk, uint64_t fin, uint64_t *fout,
163     int flags, int *stop)
164 {
165 	struct scmi_clknode_softc *clk_sc;
166 	struct scmi_clk_softc *sc;
167 
168 	clk_sc = clknode_get_softc(clk);
169 	sc = device_get_softc(clk_sc->dev);
170 
171 	dprintf("%s: %ld\n", __func__, *fout);
172 
173 	scmi_clk_set_rate(sc, clk_sc->clock_id, *fout);
174 
175 	*stop = 1;
176 
177 	return (0);
178 }
179 
180 static clknode_method_t scmi_clknode_methods[] = {
181 	/* Device interface */
182 	CLKNODEMETHOD(clknode_init,		scmi_clknode_init),
183 	CLKNODEMETHOD(clknode_recalc_freq,	scmi_clknode_recalc_freq),
184 	CLKNODEMETHOD(clknode_set_freq,		scmi_clknode_set_freq),
185 	CLKNODEMETHOD_END
186 };
187 
188 DEFINE_CLASS_1(scmi_clknode, scmi_clknode_class, scmi_clknode_methods,
189     sizeof(struct scmi_clknode_softc), clknode_class);
190 
191 static int
192 scmi_clk_add_node(struct scmi_clk_softc *sc, int index, char *clock_name)
193 {
194 	struct scmi_clknode_softc *clk_sc;
195 	struct clknode_init_def def;
196 	struct clknode *clk;
197 
198 	memset(&def, 0, sizeof(def));
199 	def.id = index;
200 	def.name = clock_name;
201 	def.parent_names = NULL;
202 	def.parent_cnt = 0;
203 
204 	clk = clknode_create(sc->clkdom, &scmi_clknode_class, &def);
205 	if (clk == NULL) {
206 		device_printf(sc->dev, "Cannot create clknode.\n");
207 		return (ENXIO);
208 	}
209 
210 	clk_sc = clknode_get_softc(clk);
211 	clk_sc->dev = sc->dev;
212 	clk_sc->clock_id = index;
213 
214 	if (clknode_register(sc->clkdom, clk) == NULL) {
215 		device_printf(sc->dev, "Could not register clock '%s'.\n",
216 		    def.name);
217 		return (ENXIO);
218 	}
219 
220 	device_printf(sc->dev, "Clock '%s' registered.\n", def.name);
221 
222 	return (0);
223 }
224 
225 static int
226 scmi_clk_get_name(struct scmi_clk_softc *sc, int index, char **result)
227 {
228 	struct scmi_clk_name_get_out out;
229 	struct scmi_clk_name_get_in in;
230 	struct scmi_req req;
231 	char *clock_name;
232 	int error;
233 
234 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
235 	req.message_id = SCMI_CLOCK_NAME_GET;
236 	req.in_buf = &in;
237 	req.in_size = sizeof(struct scmi_clk_name_get_in);
238 	req.out_buf = &out;
239 	req.out_size = sizeof(struct scmi_clk_name_get_out);
240 
241 	in.clock_id = index;
242 
243 	error = scmi_request(sc->scmi, &req);
244 	if (error != 0)
245 		return (error);
246 
247 	if (out.status != 0)
248 		return (ENXIO);
249 
250 	clock_name = malloc(sizeof(out.name), M_DEVBUF, M_WAITOK);
251 	strncpy(clock_name, out.name, sizeof(out.name));
252 
253 	*result = clock_name;
254 
255 	return (0);
256 }
257 
258 static int
259 scmi_clk_attrs(struct scmi_clk_softc *sc, int index)
260 {
261 	struct scmi_clk_attrs_out out;
262 	struct scmi_clk_attrs_in in;
263 	struct scmi_req req;
264 	int error;
265 	char *clock_name;
266 
267 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
268 	req.message_id = SCMI_CLOCK_ATTRIBUTES;
269 	req.in_buf = &in;
270 	req.in_size = sizeof(struct scmi_clk_attrs_in);
271 	req.out_buf = &out;
272 	req.out_size = sizeof(struct scmi_clk_attrs_out);
273 
274 	in.clock_id = index;
275 
276 	error = scmi_request(sc->scmi, &req);
277 	if (error != 0)
278 		return (error);
279 
280 	if (out.status != 0)
281 		return (ENXIO);
282 
283 	if (out.attributes & CLK_ATTRS_EXT_CLK_NAME) {
284 		error = scmi_clk_get_name(sc, index, &clock_name);
285 		if (error)
286 			return (error);
287 	} else {
288 		clock_name = malloc(sizeof(out.clock_name), M_DEVBUF, M_WAITOK);
289 		strncpy(clock_name, out.clock_name, sizeof(out.clock_name));
290 	}
291 
292 	error = scmi_clk_add_node(sc, index, clock_name);
293 
294 	return (error);
295 }
296 
297 static int
298 scmi_clk_discover(struct scmi_clk_softc *sc)
299 {
300 	struct scmi_clk_protocol_attrs_out out;
301 	struct scmi_req req;
302 	int nclocks;
303 	int failing;
304 	int error;
305 	int i;
306 
307 	req.protocol_id = SCMI_PROTOCOL_ID_CLOCK;
308 	req.message_id = SCMI_PROTOCOL_ATTRIBUTES;
309 	req.in_buf = NULL;
310 	req.in_size = 0;
311 	req.out_buf = &out;
312 	req.out_size = sizeof(struct scmi_clk_protocol_attrs_out);
313 
314 	error = scmi_request(sc->scmi, &req);
315 	if (error != 0)
316 		return (error);
317 
318 	if (out.status != 0)
319 		return (ENXIO);
320 
321 	nclocks = (out.attributes & CLK_ATTRS_NCLOCKS_M) >>
322 	    CLK_ATTRS_NCLOCKS_S;
323 
324 	device_printf(sc->dev, "Found %d clocks.\n", nclocks);
325 
326 	failing = 0;
327 
328 	for (i = 0; i < nclocks; i++) {
329 		error = scmi_clk_attrs(sc, i);
330 		if (error) {
331 			device_printf(sc->dev,
332 			    "Could not process clock index %d.\n", i);
333 			failing++;
334 		}
335 	}
336 
337 	if (failing == nclocks)
338 		return (ENXIO);
339 
340 	return (0);
341 }
342 
343 static int
344 scmi_clk_init(struct scmi_clk_softc *sc)
345 {
346 	int error;
347 
348 	/* Create clock domain */
349 	sc->clkdom = clkdom_create(sc->dev);
350 	if (sc->clkdom == NULL)
351 		return (ENXIO);
352 
353 	error = scmi_clk_discover(sc);
354 	if (error) {
355 		device_printf(sc->dev, "Could not discover clocks.\n");
356 		return (ENXIO);
357 	}
358 
359 	error = clkdom_finit(sc->clkdom);
360 	if (error) {
361 		device_printf(sc->dev, "Failed to init clock domain.\n");
362 		return (ENXIO);
363 	}
364 
365 	return (0);
366 }
367 
368 static int
369 scmi_clk_probe(device_t dev)
370 {
371 	phandle_t node;
372 	uint32_t reg;
373 	int error;
374 
375 	node = ofw_bus_get_node(dev);
376 
377 	error = OF_getencprop(node, "reg", &reg, sizeof(uint32_t));
378 	if (error < 0)
379 		return (ENXIO);
380 
381 	if (reg != SCMI_PROTOCOL_ID_CLOCK)
382 		return (ENXIO);
383 
384 	device_set_desc(dev, "SCMI Clock Management Unit");
385 
386 	return (BUS_PROBE_DEFAULT);
387 }
388 
389 static int
390 scmi_clk_attach(device_t dev)
391 {
392 	struct scmi_clk_softc *sc;
393 	phandle_t node;
394 
395 	sc = device_get_softc(dev);
396 	sc->dev = dev;
397 	sc->scmi = device_get_parent(dev);
398 
399 	node = ofw_bus_get_node(sc->dev);
400 
401 	OF_device_register_xref(OF_xref_from_node(node), sc->dev);
402 
403 	scmi_clk_init(sc);
404 
405 	return (0);
406 }
407 
408 static int
409 scmi_clk_detach(device_t dev)
410 {
411 
412 	return (0);
413 }
414 
415 static device_method_t scmi_clk_methods[] = {
416 	/* Device interface */
417 	DEVMETHOD(device_probe,		scmi_clk_probe),
418 	DEVMETHOD(device_attach,	scmi_clk_attach),
419 	DEVMETHOD(device_detach,	scmi_clk_detach),
420 	DEVMETHOD_END
421 };
422 
423 static driver_t scmi_clk_driver = {
424 	"scmi_clk",
425 	scmi_clk_methods,
426 	sizeof(struct scmi_clk_softc),
427 };
428 
429 EARLY_DRIVER_MODULE(scmi_clk, scmi, scmi_clk_driver, 0, 0,
430     BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);
431 MODULE_VERSION(scmi_clk, 1);
432