xref: /freebsd/sys/arm/broadcom/bcm2835/raspberrypi_gpio.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
5  * Copyright (c) 2012-2015 Luiz Otavio O Souza <loos@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_platform.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/gpio.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/sx.h>
43 #include <sys/proc.h>
44 
45 #include <dev/gpio/gpiobusvar.h>
46 #include <dev/ofw/ofw_bus.h>
47 
48 #include <arm/broadcom/bcm2835/bcm2835_firmware.h>
49 
50 #include "gpio_if.h"
51 
52 #define	RPI_FW_GPIO_PINS		8
53 #define	RPI_FW_GPIO_BASE		128
54 #define	RPI_FW_GPIO_DEFAULT_CAPS	(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)
55 
56 struct rpi_fw_gpio_softc {
57 	device_t		sc_busdev;
58 	device_t		sc_firmware;
59 	struct sx		sc_sx;
60 	struct gpio_pin		sc_gpio_pins[RPI_FW_GPIO_PINS];
61 	uint8_t			sc_gpio_state;
62 };
63 
64 #define	RPI_FW_GPIO_LOCK(_sc)	sx_xlock(&(_sc)->sc_sx)
65 #define	RPI_FW_GPIO_UNLOCK(_sc)	sx_xunlock(&(_sc)->sc_sx)
66 
67 static struct ofw_compat_data compat_data[] = {
68 	{"raspberrypi,firmware-gpio",	1},
69 	{NULL,				0}
70 };
71 
72 static int
73 rpi_fw_gpio_pin_configure(struct rpi_fw_gpio_softc *sc, struct gpio_pin *pin,
74     unsigned int flags)
75 {
76 	union msg_get_gpio_config old_cfg;
77 	union msg_set_gpio_config new_cfg;
78 	int rv;
79 
80 	bzero(&old_cfg, sizeof(old_cfg));
81 	bzero(&new_cfg, sizeof(new_cfg));
82 	old_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;
83 
84 	RPI_FW_GPIO_LOCK(sc);
85 	rv = bcm2835_firmware_property(sc->sc_firmware,
86 	    BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &old_cfg, sizeof(old_cfg));
87 	if (rv == 0 && old_cfg.resp.gpio != 0)
88 		rv = EIO;
89 	if (rv != 0)
90 		goto fail;
91 
92 	new_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;
93 	if (flags & GPIO_PIN_INPUT) {
94 		new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_IN;
95 		new_cfg.req.state = 0;
96 		pin->gp_flags = GPIO_PIN_INPUT;
97 	} else if (flags & GPIO_PIN_OUTPUT) {
98 		new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_OUT;
99 		if (flags & (GPIO_PIN_PRESET_HIGH | GPIO_PIN_PRESET_LOW)) {
100 			if (flags & GPIO_PIN_PRESET_HIGH) {
101 				new_cfg.req.state = 1;
102 				sc->sc_gpio_state |= (1 << pin->gp_pin);
103 			} else {
104 				new_cfg.req.state = 0;
105 				sc->sc_gpio_state &= ~(1 << pin->gp_pin);
106 			}
107 		} else {
108 			if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0) {
109 				new_cfg.req.state = 1;
110 			} else {
111 				new_cfg.req.state = 0;
112 			}
113 		}
114 		pin->gp_flags = GPIO_PIN_OUTPUT;
115 	} else {
116 		new_cfg.req.dir = old_cfg.resp.dir;
117 		/* Use the old state to decide high/low */
118 		if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0)
119 			new_cfg.req.state = 1;
120 		else
121 			new_cfg.req.state = 0;
122 	}
123 	new_cfg.req.pol = old_cfg.resp.pol;
124 	new_cfg.req.term_en = 0;
125 	new_cfg.req.term_pull_up = 0;
126 
127 	rv = bcm2835_firmware_property(sc->sc_firmware,
128 	    BCM2835_FIRMWARE_TAG_SET_GPIO_CONFIG, &new_cfg, sizeof(new_cfg));
129 
130 fail:
131 	RPI_FW_GPIO_UNLOCK(sc);
132 
133 	return (rv);
134 }
135 
136 static device_t
137 rpi_fw_gpio_get_bus(device_t dev)
138 {
139 	struct rpi_fw_gpio_softc *sc;
140 
141 	sc = device_get_softc(dev);
142 
143 	return (sc->sc_busdev);
144 }
145 
146 static int
147 rpi_fw_gpio_pin_max(device_t dev, int *maxpin)
148 {
149 
150 	*maxpin = RPI_FW_GPIO_PINS - 1;
151 	return (0);
152 }
153 
154 static int
155 rpi_fw_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
156 {
157 	struct rpi_fw_gpio_softc *sc;
158 	int i;
159 
160 	sc = device_get_softc(dev);
161 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
162 		if (sc->sc_gpio_pins[i].gp_pin == pin)
163 			break;
164 	}
165 
166 	if (i >= RPI_FW_GPIO_PINS)
167 		return (EINVAL);
168 
169 	*caps = RPI_FW_GPIO_DEFAULT_CAPS;
170 	return (0);
171 }
172 
173 static int
174 rpi_fw_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
175 {
176 	struct rpi_fw_gpio_softc *sc = device_get_softc(dev);
177 	int i;
178 
179 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
180 		if (sc->sc_gpio_pins[i].gp_pin == pin)
181 			break;
182 	}
183 
184 	if (i >= RPI_FW_GPIO_PINS)
185 		return (EINVAL);
186 
187 	RPI_FW_GPIO_LOCK(sc);
188 	*flags = sc->sc_gpio_pins[i].gp_flags;
189 	RPI_FW_GPIO_UNLOCK(sc);
190 
191 	return (0);
192 }
193 
194 static int
195 rpi_fw_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
196 {
197 	struct rpi_fw_gpio_softc *sc;
198 	int i;
199 
200 	sc = device_get_softc(dev);
201 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
202 		if (sc->sc_gpio_pins[i].gp_pin == pin)
203 			break;
204 	}
205 
206 	if (i >= RPI_FW_GPIO_PINS)
207 		return (EINVAL);
208 
209 	RPI_FW_GPIO_LOCK(sc);
210 	memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
211 	RPI_FW_GPIO_UNLOCK(sc);
212 
213 	return (0);
214 }
215 
216 static int
217 rpi_fw_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
218 {
219 	struct rpi_fw_gpio_softc *sc;
220 	int i;
221 
222 	sc = device_get_softc(dev);
223 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
224 		if (sc->sc_gpio_pins[i].gp_pin == pin)
225 			break;
226 	}
227 
228 	if (i >= RPI_FW_GPIO_PINS)
229 		return (EINVAL);
230 
231 	return (rpi_fw_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags));
232 }
233 
234 static int
235 rpi_fw_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
236 {
237 	struct rpi_fw_gpio_softc *sc;
238 	union msg_set_gpio_state state;
239 	int i, rv;
240 
241 	sc = device_get_softc(dev);
242 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
243 		if (sc->sc_gpio_pins[i].gp_pin == pin)
244 			break;
245 	}
246 	if (i >= RPI_FW_GPIO_PINS)
247 		return (EINVAL);
248 
249 	state.req.gpio = RPI_FW_GPIO_BASE + pin;
250 	state.req.state = value;
251 
252 	RPI_FW_GPIO_LOCK(sc);
253 	rv = bcm2835_firmware_property(sc->sc_firmware,
254 	    BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &state, sizeof(state));
255 	/* The firmware sets gpio to 0 on success */
256 	if (rv == 0 && state.resp.gpio != 0)
257 		rv = EINVAL;
258 	if (rv == 0) {
259 		sc->sc_gpio_pins[i].gp_flags &= ~(GPIO_PIN_PRESET_HIGH |
260 		    GPIO_PIN_PRESET_LOW);
261 		if (value)
262 			sc->sc_gpio_state |= (1 << i);
263 		else
264 			sc->sc_gpio_state &= ~(1 << i);
265 	}
266 	RPI_FW_GPIO_UNLOCK(sc);
267 
268 	return (rv);
269 }
270 
271 static int
272 rpi_fw_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
273 {
274 	struct rpi_fw_gpio_softc *sc;
275 	union msg_get_gpio_state state;
276 	int i, rv;
277 
278 	sc = device_get_softc(dev);
279 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
280 		if (sc->sc_gpio_pins[i].gp_pin == pin)
281 			break;
282 	}
283 	if (i >= RPI_FW_GPIO_PINS)
284 		return (EINVAL);
285 
286 	bzero(&state, sizeof(state));
287 	state.req.gpio = RPI_FW_GPIO_BASE + pin;
288 
289 	RPI_FW_GPIO_LOCK(sc);
290 	rv = bcm2835_firmware_property(sc->sc_firmware,
291 	    BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &state, sizeof(state));
292 	RPI_FW_GPIO_UNLOCK(sc);
293 
294 	/* The firmware sets gpio to 0 on success */
295 	if (rv == 0 && state.resp.gpio != 0)
296 		rv = EINVAL;
297 	if (rv == 0)
298 		*val = !state.resp.state;
299 
300 	return (rv);
301 }
302 
303 static int
304 rpi_fw_gpio_pin_toggle(device_t dev, uint32_t pin)
305 {
306 	struct rpi_fw_gpio_softc *sc;
307 	union msg_get_gpio_state old_state;
308 	union msg_set_gpio_state new_state;
309 	int i, rv;
310 
311 	sc = device_get_softc(dev);
312 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
313 		if (sc->sc_gpio_pins[i].gp_pin == pin)
314 			break;
315 	}
316 	if (i >= RPI_FW_GPIO_PINS)
317 		return (EINVAL);
318 
319 	bzero(&old_state, sizeof(old_state));
320 	bzero(&new_state, sizeof(new_state));
321 
322 	old_state.req.gpio = RPI_FW_GPIO_BASE + pin;
323 	new_state.req.gpio = RPI_FW_GPIO_BASE + pin;
324 
325 	RPI_FW_GPIO_LOCK(sc);
326 	rv = bcm2835_firmware_property(sc->sc_firmware,
327 	    BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &old_state, sizeof(old_state));
328 	/* The firmware sets gpio to 0 on success */
329 	if (rv == 0 && old_state.resp.gpio == 0) {
330 		/* Set the new state to invert the GPIO */
331 		new_state.req.state = !old_state.resp.state;
332 		rv = bcm2835_firmware_property(sc->sc_firmware,
333 		    BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &new_state,
334 		    sizeof(new_state));
335 	}
336 	if (rv == 0 && (old_state.resp.gpio != 0 || new_state.resp.gpio != 0))
337 		rv = EINVAL;
338 	RPI_FW_GPIO_UNLOCK(sc);
339 
340 	return (rv);
341 }
342 
343 static int
344 rpi_fw_gpio_probe(device_t dev)
345 {
346 
347 	if (!ofw_bus_status_okay(dev))
348 		return (ENXIO);
349 
350 	if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
351 		return (ENXIO);
352 
353 	device_set_desc(dev, "Raspberry Pi Firmware GPIO controller");
354 	return (BUS_PROBE_DEFAULT);
355 }
356 
357 static int
358 rpi_fw_gpio_attach(device_t dev)
359 {
360 	union msg_get_gpio_config cfg;
361 	struct rpi_fw_gpio_softc *sc;
362 	char *names;
363 	phandle_t gpio;
364 	int i, nelems, elm_pos, rv;
365 
366 	sc = device_get_softc(dev);
367 	sc->sc_firmware = device_get_parent(dev);
368 	sx_init(&sc->sc_sx, "Raspberry Pi firmware gpio");
369 	/* Find our node. */
370 	gpio = ofw_bus_get_node(dev);
371 	if (!OF_hasprop(gpio, "gpio-controller"))
372 		/* This is not a GPIO controller. */
373 		goto fail;
374 
375 	nelems = OF_getprop_alloc(gpio, "gpio-line-names", (void **)&names);
376 	if (nelems <= 0)
377 		names = NULL;
378 	elm_pos = 0;
379 	for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
380 		/* Set the current pin name */
381 		if (names != NULL && elm_pos < nelems &&
382 		    names[elm_pos] != '\0') {
383 			snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
384 			    "%s", names + elm_pos);
385 			/* Find the next pin name */
386 			elm_pos += strlen(names + elm_pos) + 1;
387 		} else {
388 			snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
389 			    "pin %d", i);
390 		}
391 
392 		sc->sc_gpio_pins[i].gp_pin = i;
393 		sc->sc_gpio_pins[i].gp_caps = RPI_FW_GPIO_DEFAULT_CAPS;
394 
395 		bzero(&cfg, sizeof(cfg));
396 		cfg.req.gpio = RPI_FW_GPIO_BASE + i;
397 		rv = bcm2835_firmware_property(sc->sc_firmware,
398 		    BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &cfg, sizeof(cfg));
399 		if (rv == 0 && cfg.resp.gpio == 0) {
400 			if (cfg.resp.dir == BCM2835_FIRMWARE_GPIO_IN)
401 				sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
402 			else
403 				sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_OUTPUT;
404 		} else {
405 			sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
406 		}
407 	}
408 	free(names, M_OFWPROP);
409 	sc->sc_busdev = gpiobus_attach_bus(dev);
410 	if (sc->sc_busdev == NULL)
411 		goto fail;
412 
413 	return (0);
414 
415 fail:
416 	sx_destroy(&sc->sc_sx);
417 
418 	return (ENXIO);
419 }
420 
421 static int
422 rpi_fw_gpio_detach(device_t dev)
423 {
424 
425 	return (EBUSY);
426 }
427 
428 static device_method_t rpi_fw_gpio_methods[] = {
429 	/* Device interface */
430 	DEVMETHOD(device_probe,		rpi_fw_gpio_probe),
431 	DEVMETHOD(device_attach,	rpi_fw_gpio_attach),
432 	DEVMETHOD(device_detach,	rpi_fw_gpio_detach),
433 
434 	/* GPIO protocol */
435 	DEVMETHOD(gpio_get_bus,		rpi_fw_gpio_get_bus),
436 	DEVMETHOD(gpio_pin_max,		rpi_fw_gpio_pin_max),
437 	DEVMETHOD(gpio_pin_getname,	rpi_fw_gpio_pin_getname),
438 	DEVMETHOD(gpio_pin_getflags,	rpi_fw_gpio_pin_getflags),
439 	DEVMETHOD(gpio_pin_getcaps,	rpi_fw_gpio_pin_getcaps),
440 	DEVMETHOD(gpio_pin_setflags,	rpi_fw_gpio_pin_setflags),
441 	DEVMETHOD(gpio_pin_get,		rpi_fw_gpio_pin_get),
442 	DEVMETHOD(gpio_pin_set,		rpi_fw_gpio_pin_set),
443 	DEVMETHOD(gpio_pin_toggle,	rpi_fw_gpio_pin_toggle),
444 
445 	DEVMETHOD_END
446 };
447 
448 static devclass_t rpi_fw_gpio_devclass;
449 
450 static driver_t rpi_fw_gpio_driver = {
451 	"gpio",
452 	rpi_fw_gpio_methods,
453 	sizeof(struct rpi_fw_gpio_softc),
454 };
455 
456 EARLY_DRIVER_MODULE(rpi_fw_gpio, bcm2835_firmware, rpi_fw_gpio_driver,
457     rpi_fw_gpio_devclass, 0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LATE);
458