xref: /freebsd/sys/dev/gpio/gpioled.c (revision fdb3b695a4d19f098367be4fe2df51bec991170d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include "opt_platform.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/gpio.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 
42 #include <dev/gpio/gpiobusvar.h>
43 #include <dev/led/led.h>
44 
45 #include "gpiobus_if.h"
46 
47 /*
48  * Only one pin for led
49  */
50 #define	GPIOLED_PIN	0
51 
52 #define	GPIOLED_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
53 #define	GPIOLED_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
54 #define	GPIOLED_LOCK_INIT(_sc)		mtx_init(&(_sc)->sc_mtx,	\
55     device_get_nameunit((_sc)->sc_dev), "gpioled", MTX_DEF)
56 #define	GPIOLED_LOCK_DESTROY(_sc)	mtx_destroy(&(_sc)->sc_mtx)
57 
58 struct gpioled_softc
59 {
60 	device_t	sc_dev;
61 	device_t	sc_busdev;
62 	struct mtx	sc_mtx;
63 	struct cdev	*sc_leddev;
64 	int	sc_softinvert;
65 };
66 
67 static void gpioled_control(void *, int);
68 static int gpioled_probe(device_t);
69 static int gpioled_attach(device_t);
70 static int gpioled_detach(device_t);
71 
72 static void
73 gpioled_control(void *priv, int onoff)
74 {
75 	struct gpioled_softc *sc;
76 
77 	sc = (struct gpioled_softc *)priv;
78 	if (onoff == -1) /* Keep the current state. */
79 		return;
80 	if (sc->sc_softinvert)
81 		onoff = !onoff;
82 	GPIOLED_LOCK(sc);
83 	GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, GPIOLED_PIN,
84 	    onoff ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
85 	GPIOLED_UNLOCK(sc);
86 }
87 
88 static int
89 gpioled_probe(device_t dev)
90 {
91 	device_set_desc(dev, "GPIO led");
92 
93 	return (BUS_PROBE_DEFAULT);
94 }
95 
96 static int
97 gpioled_inv(device_t dev, uint32_t *pin_flags)
98 {
99 	struct gpioled_softc *sc;
100 	int invert;
101 	uint32_t pin_caps;
102 
103 	sc = device_get_softc(dev);
104 
105 	if (resource_int_value(device_get_name(dev),
106 	    device_get_unit(dev), "invert", &invert))
107 		invert = 0;
108 
109 	if (GPIOBUS_PIN_GETCAPS(sc->sc_busdev, sc->sc_dev, GPIOLED_PIN,
110 	    &pin_caps) != 0) {
111 		if (bootverbose)
112 			device_printf(sc->sc_dev, "unable to get pin caps\n");
113 		return (-1);
114 	}
115 	if (pin_caps & GPIO_PIN_INVOUT)
116 		*pin_flags &= ~GPIO_PIN_INVOUT;
117 	sc->sc_softinvert = 0;
118 	if (invert) {
119 		const char *invmode;
120 
121 		if (resource_string_value(device_get_name(dev),
122 		    device_get_unit(dev), "invmode", &invmode))
123 			invmode = NULL;
124 
125 		if (invmode) {
126 			if (!strcmp(invmode, "sw"))
127 				sc->sc_softinvert = 1;
128 			else if (!strcmp(invmode, "hw")) {
129 				if (pin_caps & GPIO_PIN_INVOUT)
130 					*pin_flags |= GPIO_PIN_INVOUT;
131 				else {
132 					device_printf(sc->sc_dev, "hardware pin inversion not supported\n");
133 					return (-1);
134 				}
135 			} else {
136 				if (strcmp(invmode, "auto") != 0)
137 					device_printf(sc->sc_dev, "invalid pin inversion mode\n");
138 				invmode = NULL;
139 			}
140 		}
141 		/*
142 		 * auto inversion mode: use hardware support if available, else fallback to
143 		 * software emulation.
144 		 */
145 		if (invmode == NULL) {
146 			if (pin_caps & GPIO_PIN_INVOUT)
147 				*pin_flags |= GPIO_PIN_INVOUT;
148 			else
149 				sc->sc_softinvert = 1;
150 		}
151 	}
152 	MPASS(!invert ||
153 	    (((*pin_flags & GPIO_PIN_INVOUT) != 0) && !sc->sc_softinvert) ||
154 	    (((*pin_flags & GPIO_PIN_INVOUT) == 0) && sc->sc_softinvert));
155 	return (invert);
156 }
157 
158 static int
159 gpioled_attach(device_t dev)
160 {
161 	struct gpioled_softc *sc;
162 	int state;
163 	const char *name;
164 	uint32_t pin_flags;
165 	int invert;
166 
167 	sc = device_get_softc(dev);
168 	sc->sc_dev = dev;
169 	sc->sc_busdev = device_get_parent(dev);
170 	GPIOLED_LOCK_INIT(sc);
171 
172 	if (resource_string_value(device_get_name(dev),
173 	    device_get_unit(dev), "name", &name))
174 		name = NULL;
175 
176 	if (resource_int_value(device_get_name(dev),
177 	    device_get_unit(dev), "state", &state))
178 		state = 0;
179 
180 	pin_flags = GPIO_PIN_OUTPUT;
181 	invert = gpioled_inv(dev, &pin_flags);
182 	if (invert < 0)
183 		return (ENXIO);
184 	device_printf(sc->sc_dev, "state %d invert %s\n",
185 	    state, (invert ? (sc->sc_softinvert ? "sw" : "hw") : "no"));
186 	if (GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, GPIOLED_PIN,
187 	    pin_flags) != 0) {
188 		if (bootverbose)
189 			device_printf(sc->sc_dev, "unable to set pin flags, %#x\n", pin_flags);
190 		return (ENXIO);
191 	}
192 
193 	sc->sc_leddev = led_create_state(gpioled_control, sc, name ? name :
194 	    device_get_nameunit(dev), state);
195 
196 	return (0);
197 }
198 
199 static int
200 gpioled_detach(device_t dev)
201 {
202 	struct gpioled_softc *sc;
203 
204 	sc = device_get_softc(dev);
205 	if (sc->sc_leddev) {
206 		led_destroy(sc->sc_leddev);
207 		sc->sc_leddev = NULL;
208 	}
209 	GPIOLED_LOCK_DESTROY(sc);
210 	return (0);
211 }
212 
213 static device_method_t gpioled_methods[] = {
214 	/* Device interface */
215 	DEVMETHOD(device_probe,		gpioled_probe),
216 	DEVMETHOD(device_attach,	gpioled_attach),
217 	DEVMETHOD(device_detach,	gpioled_detach),
218 
219 	DEVMETHOD_END
220 };
221 
222 static driver_t gpioled_driver = {
223 	"gpioled",
224 	gpioled_methods,
225 	sizeof(struct gpioled_softc),
226 };
227 
228 DRIVER_MODULE(gpioled, gpiobus, gpioled_driver, 0, 0);
229 MODULE_DEPEND(gpioled, gpiobus, 1, 1, 1);
230 MODULE_VERSION(gpioled, 1);
231