xref: /freebsd/sys/dev/regulator/regulator_fixed.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0) 
1 /*-
2  * Copyright 2016 Michal Meloun <mmel@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 #include "opt_platform.h"
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/bus.h>
32 #include <sys/conf.h>
33 #include <sys/gpio.h>
34 #include <sys/kernel.h>
35 #include <sys/kobj.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 
39 #ifdef FDT
40 #include <dev/fdt/fdt_common.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 #endif
44 #include <dev/gpio/gpiobusvar.h>
45 #include <dev/regulator/regulator_fixed.h>
46 
47 #ifdef FDT
48 #include "regdev_if.h"
49 #endif
50 
51 MALLOC_DEFINE(M_FIXEDREGULATOR, "fixedregulator", "Fixed regulator");
52 
53 /* GPIO list for shared pins. */
54 typedef TAILQ_HEAD(gpio_list, gpio_entry) gpio_list_t;
55 struct gpio_entry {
56 	TAILQ_ENTRY(gpio_entry)	link;
57 	struct gpiobus_pin	gpio_pin;
58 	int 			use_cnt;
59 	int 			enable_cnt;
60 	bool			always_on;
61 };
62 static gpio_list_t gpio_list = TAILQ_HEAD_INITIALIZER(gpio_list);
63 static struct mtx gpio_list_mtx;
64 MTX_SYSINIT(gpio_list_lock, &gpio_list_mtx, "Regulator GPIO lock", MTX_DEF);
65 
66 struct regnode_fixed_sc {
67 	struct regnode_std_param *param;
68 	bool			gpio_open_drain;
69 	struct gpio_entry	*gpio_entry;
70 };
71 
72 static int regnode_fixed_init(struct regnode *regnode);
73 static int regnode_fixed_enable(struct regnode *regnode, bool enable,
74     int *udelay);
75 static int regnode_fixed_status(struct regnode *regnode, int *status);
76 static int regnode_fixed_stop(struct regnode *regnode, int *udelay);
77 static int regnode_fixed_get_voltage(struct regnode *regnode, int *uvolt);
78 
79 static regnode_method_t regnode_fixed_methods[] = {
80 	/* Regulator interface */
81 	REGNODEMETHOD(regnode_init,		regnode_fixed_init),
82 	REGNODEMETHOD(regnode_enable,		regnode_fixed_enable),
83 	REGNODEMETHOD(regnode_status,		regnode_fixed_status),
84 	REGNODEMETHOD(regnode_stop,		regnode_fixed_stop),
85 	REGNODEMETHOD(regnode_get_voltage,	regnode_fixed_get_voltage),
86 	REGNODEMETHOD(regnode_check_voltage,	regnode_method_check_voltage),
87 	REGNODEMETHOD_END
88 };
89 DEFINE_CLASS_1(regnode_fixed, regnode_fixed_class, regnode_fixed_methods,
90    sizeof(struct regnode_fixed_sc), regnode_class);
91 
92 /*
93  * GPIO list functions.
94  * Two or more regulators can share single GPIO pins, so we must track all
95  * GPIOs in gpio_list.
96  * The GPIO pin is registerd and reseved for first consumer, all others share
97  * gpio_entry with it.
98  */
99 static struct gpio_entry *
100 regnode_get_gpio_entry(struct gpiobus_pin *gpio_pin)
101 {
102 	struct gpio_entry *entry, *tmp;
103 	device_t busdev;
104 	int rv;
105 
106 	busdev = GPIO_GET_BUS(gpio_pin->dev);
107 	if (busdev == NULL)
108 		return (NULL);
109 	entry = malloc(sizeof(struct gpio_entry), M_FIXEDREGULATOR,
110 	    M_WAITOK | M_ZERO);
111 
112 	mtx_lock(&gpio_list_mtx);
113 
114 	TAILQ_FOREACH(tmp, &gpio_list, link) {
115 		if (tmp->gpio_pin.dev == gpio_pin->dev &&
116 		    tmp->gpio_pin.pin == gpio_pin->pin) {
117 			tmp->use_cnt++;
118 			mtx_unlock(&gpio_list_mtx);
119 			free(entry, M_FIXEDREGULATOR);
120 			return (tmp);
121 		}
122 	}
123 
124 	/* Reserve pin. */
125 	/* XXX Can we call gpiobus_acquire_pin() with gpio_list_mtx held? */
126 	rv = gpiobus_acquire_pin(busdev, gpio_pin->pin);
127 	if (rv != 0) {
128 		mtx_unlock(&gpio_list_mtx);
129 		free(entry, M_FIXEDREGULATOR);
130 		return (NULL);
131 	}
132 	/* Everything is OK, build new entry and insert it to list. */
133 	entry->gpio_pin = *gpio_pin;
134 	entry->use_cnt = 1;
135 	TAILQ_INSERT_TAIL(&gpio_list, entry, link);
136 
137 	mtx_unlock(&gpio_list_mtx);
138 	return (entry);
139 }
140 
141 
142 /*
143  * Regulator class implementation.
144  */
145 static int
146 regnode_fixed_init(struct regnode *regnode)
147 {
148 	device_t dev;
149 	struct regnode_fixed_sc *sc;
150 	struct gpiobus_pin *pin;
151 	uint32_t flags;
152 	int rv;
153 
154 	sc = regnode_get_softc(regnode);
155 	dev = regnode_get_device(regnode);
156 	sc->param = regnode_get_stdparam(regnode);
157 	if (sc->gpio_entry == NULL)
158 		return (0);
159 	pin = &sc->gpio_entry->gpio_pin;
160 
161 	flags = GPIO_PIN_OUTPUT;
162 	if (sc->gpio_open_drain)
163 		flags |= GPIO_PIN_OPENDRAIN;
164 	if (sc->param->boot_on || sc->param->always_on) {
165 		rv = GPIO_PIN_SET(pin->dev, pin->pin, sc->param->enable_active_high);
166 		if (rv != 0) {
167 			device_printf(dev, "Cannot set GPIO pin: %d\n",
168 			    pin->pin);
169 			return (rv);
170 		}
171 	}
172 
173 	rv = GPIO_PIN_SETFLAGS(pin->dev, pin->pin, flags);
174 	if (rv != 0) {
175 		device_printf(dev, "Cannot configure GPIO pin: %d\n", pin->pin);
176 		return (rv);
177 	}
178 
179 	return (0);
180 }
181 
182 /*
183  * Enable/disable regulator.
184  * Take shared GPIO pins in account
185  */
186 static int
187 regnode_fixed_enable(struct regnode *regnode, bool enable, int *udelay)
188 {
189 	device_t dev;
190 	struct regnode_fixed_sc *sc;
191 	struct gpiobus_pin *pin;
192 	int rv;
193 
194 	sc = regnode_get_softc(regnode);
195 	dev = regnode_get_device(regnode);
196 
197 	*udelay = 0;
198 	if (sc->gpio_entry == NULL)
199 		return (0);
200 	pin = &sc->gpio_entry->gpio_pin;
201 	if (enable) {
202 		sc->gpio_entry->enable_cnt++;
203 		if (sc->gpio_entry->enable_cnt > 1)
204 			return (0);
205 	} else {
206 		KASSERT(sc->gpio_entry->enable_cnt > 0,
207 		    ("Invalid enable count"));
208 		sc->gpio_entry->enable_cnt--;
209 		if (sc->gpio_entry->enable_cnt >= 1)
210 			return (0);
211 	}
212 	if (sc->gpio_entry->always_on && !enable)
213 		return (0);
214 	if (!sc->param->enable_active_high)
215 		enable = !enable;
216 	rv = GPIO_PIN_SET(pin->dev, pin->pin, enable);
217 	if (rv != 0) {
218 		device_printf(dev, "Cannot set GPIO pin: %d\n", pin->pin);
219 		return (rv);
220 	}
221 	*udelay = sc->param->enable_delay;
222 	return (0);
223 }
224 
225 /*
226  * Stop (physicaly shutdown) regulator.
227  * Take shared GPIO pins in account
228  */
229 static int
230 regnode_fixed_stop(struct regnode *regnode, int *udelay)
231 {
232 	device_t dev;
233 	struct regnode_fixed_sc *sc;
234 	struct gpiobus_pin *pin;
235 	int rv;
236 
237 	sc = regnode_get_softc(regnode);
238 	dev = regnode_get_device(regnode);
239 
240 	*udelay = 0;
241 	if (sc->gpio_entry == NULL)
242 		return (0);
243 	if (sc->gpio_entry->always_on)
244 		return (0);
245 	pin = &sc->gpio_entry->gpio_pin;
246 	if (sc->gpio_entry->enable_cnt > 0) {
247 		/* Other regulator(s) are enabled. */
248 		/* XXXX Any diagnostic message? Or error? */
249 		return (0);
250 	}
251 	rv = GPIO_PIN_SET(pin->dev, pin->pin,
252 	    sc->param->enable_active_high ? false: true);
253 	if (rv != 0) {
254 		device_printf(dev, "Cannot set GPIO pin: %d\n", pin->pin);
255 		return (rv);
256 	}
257 	*udelay = sc->param->enable_delay;
258 	return (0);
259 }
260 
261 static int
262 regnode_fixed_status(struct regnode *regnode, int *status)
263 {
264 	struct regnode_fixed_sc *sc;
265 	struct gpiobus_pin *pin;
266 	uint32_t val;
267 	int rv;
268 
269 	sc = regnode_get_softc(regnode);
270 
271 	*status = 0;
272 	if (sc->gpio_entry == NULL) {
273 		*status = REGULATOR_STATUS_ENABLED;
274 		return (0);
275 	}
276 	pin = &sc->gpio_entry->gpio_pin;
277 
278 	rv = GPIO_PIN_GET(pin->dev, pin->pin, &val);
279 	if (rv == 0) {
280 		if (!sc->param->enable_active_high ^ (val != 0))
281 			*status = REGULATOR_STATUS_ENABLED;
282 	}
283 	return (rv);
284 }
285 
286 static int
287 regnode_fixed_get_voltage(struct regnode *regnode, int *uvolt)
288 {
289 	struct regnode_fixed_sc *sc;
290 
291 	sc = regnode_get_softc(regnode);
292 	*uvolt = sc->param->min_uvolt;
293 	return (0);
294 }
295 
296 int
297 regnode_fixed_register(device_t dev, struct regnode_fixed_init_def *init_def)
298 {
299 	struct regnode *regnode;
300 	struct regnode_fixed_sc *sc;
301 
302 	regnode = regnode_create(dev, &regnode_fixed_class,
303 	    &init_def->reg_init_def);
304 	if (regnode == NULL) {
305 		device_printf(dev, "Cannot create regulator.\n");
306 		return(ENXIO);
307 	}
308 	sc = regnode_get_softc(regnode);
309 	sc->gpio_open_drain = init_def->gpio_open_drain;
310 	if (init_def->gpio_pin != NULL) {
311 		sc->gpio_entry = regnode_get_gpio_entry(init_def->gpio_pin);
312 		if (sc->gpio_entry == NULL)
313 			return(ENXIO);
314 	}
315 	regnode = regnode_register(regnode);
316 	if (regnode == NULL) {
317 		device_printf(dev, "Cannot register regulator.\n");
318 		return(ENXIO);
319 	}
320 
321 	if (sc->gpio_entry != NULL)
322 		sc->gpio_entry->always_on |= sc->param->always_on;
323 
324 	return (0);
325 }
326 
327 /*
328  * OFW Driver implementation.
329  */
330 #ifdef FDT
331 
332 struct  regfix_softc
333 {
334 	device_t			dev;
335 	bool				attach_done;
336 	struct regnode_fixed_init_def	init_def;
337 	phandle_t			gpio_prodxref;
338 	pcell_t				*gpio_cells;
339 	int				gpio_ncells;
340 	struct gpiobus_pin		gpio_pin;
341 };
342 
343 static struct ofw_compat_data compat_data[] = {
344 	{"regulator-fixed",		1},
345 	{NULL,				0},
346 };
347 
348 static int
349 regfix_get_gpio(struct regfix_softc * sc)
350 {
351 	device_t busdev;
352 	phandle_t node;
353 
354 	int rv;
355 
356 	if (sc->gpio_prodxref == 0)
357 		return (0);
358 
359 	node = ofw_bus_get_node(sc->dev);
360 
361 	/* Test if controller exist. */
362 	sc->gpio_pin.dev = OF_device_from_xref(sc->gpio_prodxref);
363 	if (sc->gpio_pin.dev == NULL)
364 		return (ENODEV);
365 
366 	/* Test if GPIO bus already exist. */
367 	busdev = GPIO_GET_BUS(sc->gpio_pin.dev);
368 	if (busdev == NULL)
369 		return (ENODEV);
370 
371 	rv = gpio_map_gpios(sc->gpio_pin.dev, node,
372 	    OF_node_from_xref(sc->gpio_prodxref), sc->gpio_ncells,
373 	    sc->gpio_cells, &(sc->gpio_pin.pin), &(sc->gpio_pin.flags));
374 	if (rv != 0) {
375 		device_printf(sc->dev, "Cannot map the gpio property.\n");
376 		return (ENXIO);
377 	}
378 	sc->init_def.gpio_pin = &sc->gpio_pin;
379 	return (0);
380 }
381 
382 static int
383 regfix_parse_fdt(struct regfix_softc * sc)
384 {
385 	phandle_t node;
386 	int rv;
387 	struct regnode_init_def *init_def;
388 
389 	node = ofw_bus_get_node(sc->dev);
390 	init_def = &sc->init_def.reg_init_def;
391 
392 	rv = regulator_parse_ofw_stdparam(sc->dev, node, init_def);
393 	if (rv != 0) {
394 		device_printf(sc->dev, "Cannot parse standard parameters.\n");
395 		return(rv);
396 	}
397 
398 	if (init_def->std_param.min_uvolt != init_def->std_param.max_uvolt) {
399 		device_printf(sc->dev, "min_uvolt != max_uvolt\n");
400 		return (ENXIO);
401 	}
402 	/* Fixed regulator uses 'startup-delay-us' property for enable_delay */
403 	rv = OF_getencprop(node, "startup-delay-us",
404 	   &init_def->std_param.enable_delay,
405 	   sizeof(init_def->std_param.enable_delay));
406 	if (rv <= 0)
407 		init_def->std_param.enable_delay = 0;
408 	/* GPIO pin */
409 	if (OF_hasprop(node, "gpio-open-drain"))
410 		sc->init_def.gpio_open_drain = true;
411 
412 	if (!OF_hasprop(node, "gpio"))
413 		return (0);
414 	rv = ofw_bus_parse_xref_list_alloc(node, "gpio", "#gpio-cells", 0,
415 	    &sc->gpio_prodxref, &sc->gpio_ncells, &sc->gpio_cells);
416 	if (rv != 0) {
417 		sc->gpio_prodxref = 0;
418 		device_printf(sc->dev, "Malformed gpio property\n");
419 		return (ENXIO);
420 	}
421 	return (0);
422 }
423 
424 static void
425 regfix_new_pass(device_t dev)
426 {
427 	struct regfix_softc * sc;
428 	int rv;
429 
430 	sc = device_get_softc(dev);
431 	bus_generic_new_pass(dev);
432 
433 	if (sc->attach_done)
434 		return;
435 
436 	/* Try to get and configure GPIO. */
437 	rv = regfix_get_gpio(sc);
438 	if (rv != 0)
439 		return;
440 
441 	/* Register regulator. */
442 	regnode_fixed_register(sc->dev, &sc->init_def);
443 	sc->attach_done = true;
444 }
445 
446 static int
447 regfix_probe(device_t dev)
448 {
449 
450 	if (!ofw_bus_status_okay(dev))
451 		return (ENXIO);
452 
453 	if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
454 		return (ENXIO);
455 
456 	device_set_desc(dev, "Fixed Regulator");
457 	return (BUS_PROBE_DEFAULT);
458 }
459 
460 static int
461 regfix_detach(device_t dev)
462 {
463 
464 	/* This device is always present. */
465 	return (EBUSY);
466 }
467 
468 static int
469 regfix_attach(device_t dev)
470 {
471 	struct regfix_softc * sc;
472 	int rv;
473 
474 	sc = device_get_softc(dev);
475 	sc->dev = dev;
476 
477 	/* Parse FDT data. */
478 	rv = regfix_parse_fdt(sc);
479 	if (rv != 0)
480 		return(ENXIO);
481 
482 	/* Fill reset of init. */
483 	sc->init_def.reg_init_def.id = 1;
484 	sc->init_def.reg_init_def.flags = REGULATOR_FLAGS_STATIC;
485 
486 	/* Try to get and configure GPIO. */
487 	rv = regfix_get_gpio(sc);
488 	if (rv != 0)
489 		return (bus_generic_attach(dev));
490 
491 	/* Register regulator. */
492 	regnode_fixed_register(sc->dev, &sc->init_def);
493 	sc->attach_done = true;
494 
495 	return (bus_generic_attach(dev));
496 }
497 
498 static device_method_t regfix_methods[] = {
499 	/* Device interface */
500 	DEVMETHOD(device_probe,		regfix_probe),
501 	DEVMETHOD(device_attach,	regfix_attach),
502 	DEVMETHOD(device_detach,	regfix_detach),
503 	/* Bus interface */
504 	DEVMETHOD(bus_new_pass,		regfix_new_pass),
505 	/* Regdev interface */
506 	DEVMETHOD(regdev_map,		regdev_default_ofw_map),
507 
508 	DEVMETHOD_END
509 };
510 
511 DEFINE_CLASS_0(regfix, regfix_driver, regfix_methods,
512     sizeof(struct regfix_softc));
513 EARLY_DRIVER_MODULE(regfix, simplebus, regfix_driver, 0, 0, BUS_PASS_BUS);
514 
515 #endif /* FDT */
516