xref: /netbsd-src/sys/dev/gpio/gpio.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /* $NetBSD: gpio.c,v 1.8 2006/04/08 22:33:36 uwe Exp $ */
2 /*	$OpenBSD: gpio.c,v 1.6 2006/01/14 12:33:49 grange Exp $	*/
3 
4 /*
5  * Copyright (c) 2004, 2006 Alexander Yurchenko <grange@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/cdefs.h>
21 __KERNEL_RCSID(0, "$NetBSD: gpio.c,v 1.8 2006/04/08 22:33:36 uwe Exp $");
22 
23 /*
24  * General Purpose Input/Output framework.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/conf.h>
30 #include <sys/device.h>
31 #include <sys/ioctl.h>
32 #include <sys/gpio.h>
33 #include <sys/vnode.h>
34 
35 #include <dev/gpio/gpiovar.h>
36 
37 #include "locators.h"
38 
39 struct gpio_softc {
40 	struct device sc_dev;
41 
42 	gpio_chipset_tag_t sc_gc;	/* our GPIO controller */
43 	gpio_pin_t *sc_pins;		/* pins array */
44 	int sc_npins;			/* total number of pins */
45 
46 	int sc_opened;
47 	int sc_dying;
48 };
49 
50 int	gpio_match(struct device *, struct cfdata *, void *);
51 void	gpio_attach(struct device *, struct device *, void *);
52 int	gpio_detach(struct device *, int);
53 int	gpio_activate(struct device *, enum devact);
54 int	gpio_search(struct device *, struct cfdata *, const int *, void *);
55 int	gpio_print(void *, const char *);
56 
57 CFATTACH_DECL(gpio, sizeof(struct gpio_softc),
58     gpio_match, gpio_attach, gpio_detach, gpio_activate);
59 
60 dev_type_open(gpioopen);
61 dev_type_close(gpioclose);
62 dev_type_ioctl(gpioioctl);
63 
64 const struct cdevsw gpio_cdevsw = {
65 	gpioopen, gpioclose, noread, nowrite, gpioioctl,
66 	nostop, notty, nopoll, nommap, nokqfilter,
67 };
68 
69 extern struct cfdriver gpio_cd;
70 
71 int
72 gpio_match(struct device *parent, struct cfdata *cf, void *aux)
73 {
74 
75 	return (1);
76 }
77 
78 void
79 gpio_attach(struct device *parent, struct device *self, void *aux)
80 {
81 	struct gpio_softc *sc = device_private(self);
82 	struct gpiobus_attach_args *gba = aux;
83 
84 	sc->sc_gc = gba->gba_gc;
85 	sc->sc_pins = gba->gba_pins;
86 	sc->sc_npins = gba->gba_npins;
87 
88 	printf(": %d pins\n", sc->sc_npins);
89 
90 	/*
91 	 * Attach all devices that can be connected to the GPIO pins
92 	 * described in the kernel configuration file.
93 	 */
94 	config_search_ia(gpio_search, self, "gpio", sc);
95 }
96 
97 int
98 gpio_detach(struct device *self, int flags)
99 {
100 #if 0
101 	int maj, mn;
102 
103 	/* Locate the major number */
104 	for (maj = 0; maj < nchrdev; maj++)
105 		if (cdevsw[maj].d_open == gpioopen)
106 			break;
107 
108 	/* Nuke the vnodes for any open instances (calls close) */
109 	mn = device_unit(self);
110 	vdevgone(maj, mn, mn, VCHR);
111 #endif
112 
113 	return (0);
114 }
115 
116 int
117 gpio_activate(struct device *self, enum devact act)
118 {
119 	struct gpio_softc *sc = device_private(self);
120 
121 	switch (act) {
122 	case DVACT_ACTIVATE:
123 		return (EOPNOTSUPP);
124 	case DVACT_DEACTIVATE:
125 		sc->sc_dying = 1;
126 		break;
127 	}
128 
129 	return (0);
130 }
131 
132 int
133 gpio_search(struct device *parent, struct cfdata *cf,
134 	    const int *ldesc, void *aux)
135 {
136 	struct gpio_attach_args ga;
137 
138 	ga.ga_gpio = aux;
139 	ga.ga_offset = cf->cf_loc[GPIOCF_OFFSET];
140 	ga.ga_mask = cf->cf_loc[GPIOCF_MASK];
141 
142 	if (config_match(parent, cf, &ga) > 0)
143 		config_attach(parent, cf, &ga, gpio_print);
144 
145 	return (0);
146 }
147 
148 int
149 gpio_print(void *aux, const char *pnp)
150 {
151 	struct gpio_attach_args *ga = aux;
152 	int i;
153 
154 	printf(" pins");
155 	for (i = 0; i < 32; i++)
156 		if (ga->ga_mask & (1 << i))
157 			printf(" %d", ga->ga_offset + i);
158 
159 	return (UNCONF);
160 }
161 
162 int
163 gpiobus_print(void *aux, const char *pnp)
164 {
165 #if 0
166 	struct gpiobus_attach_args *gba = aux;
167 #endif
168 	if (pnp != NULL)
169 		printf("%s at %s", "gpiobus", pnp);
170 
171 	return (UNCONF);
172 }
173 
174 int
175 gpio_pin_map(void *gpio, int offset, u_int32_t mask, struct gpio_pinmap *map)
176 {
177 	struct gpio_softc *sc = gpio;
178 	int npins, pin, i;
179 
180 	npins = gpio_npins(mask);
181 	if (npins > sc->sc_npins)
182 		return (1);
183 
184 	for (npins = 0, i = 0; i < 32; i++)
185 		if (mask & (1 << i)) {
186 			pin = offset + i;
187 			if (pin < 0 || pin >= sc->sc_npins)
188 				return (1);
189 			if (sc->sc_pins[pin].pin_mapped)
190 				return (1);
191 			sc->sc_pins[pin].pin_mapped = 1;
192 			map->pm_map[npins++] = pin;
193 		}
194 	map->pm_size = npins;
195 
196 	return (0);
197 }
198 
199 void
200 gpio_pin_unmap(void *gpio, struct gpio_pinmap *map)
201 {
202 	struct gpio_softc *sc = gpio;
203 	int pin, i;
204 
205 	for (i = 0; i < map->pm_size; i++) {
206 		pin = map->pm_map[i];
207 		sc->sc_pins[pin].pin_mapped = 0;
208 	}
209 }
210 
211 int
212 gpio_pin_read(void *gpio, struct gpio_pinmap *map, int pin)
213 {
214 	struct gpio_softc *sc = gpio;
215 
216 	return (gpiobus_pin_read(sc->sc_gc, map->pm_map[pin]));
217 }
218 
219 void
220 gpio_pin_write(void *gpio, struct gpio_pinmap *map, int pin, int value)
221 {
222 	struct gpio_softc *sc = gpio;
223 
224 	return (gpiobus_pin_write(sc->sc_gc, map->pm_map[pin], value));
225 }
226 
227 void
228 gpio_pin_ctl(void *gpio, struct gpio_pinmap *map, int pin, int flags)
229 {
230 	struct gpio_softc *sc = gpio;
231 
232 	return (gpiobus_pin_ctl(sc->sc_gc, map->pm_map[pin], flags));
233 }
234 
235 int
236 gpio_pin_caps(void *gpio, struct gpio_pinmap *map, int pin)
237 {
238 	struct gpio_softc *sc = gpio;
239 
240 	return (sc->sc_pins[map->pm_map[pin]].pin_caps);
241 }
242 
243 int
244 gpio_npins(u_int32_t mask)
245 {
246 	int npins, i;
247 
248 	for (npins = 0, i = 0; i < 32; i++)
249 		if (mask & (1 << i))
250 			npins++;
251 
252 	return (npins);
253 }
254 
255 int
256 gpioopen(dev_t dev, int flag, int mode, struct lwp *l)
257 {
258 	struct gpio_softc *sc;
259 
260 	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
261 	if (sc == NULL)
262 		return (ENXIO);
263 
264 	if (sc->sc_opened)
265 		return (EBUSY);
266 	sc->sc_opened = 1;
267 
268 	return (0);
269 }
270 
271 int
272 gpioclose(dev_t dev, int flag, int mode, struct lwp *l)
273 {
274 	struct gpio_softc *sc;
275 
276 	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
277 	sc->sc_opened = 0;
278 
279 	return (0);
280 }
281 
282 int
283 gpioioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
284 {
285 	struct gpio_softc *sc;
286 	gpio_chipset_tag_t gc;
287 	struct gpio_info *info;
288 	struct gpio_pin_op *op;
289 	struct gpio_pin_ctl *ctl;
290 	int pin, value, flags;
291 
292 	sc = (struct gpio_softc *)device_lookup(&gpio_cd, minor(dev));
293 	gc = sc->sc_gc;
294 
295 	switch (cmd) {
296 	case GPIOINFO:
297 		info = (struct gpio_info *)data;
298 
299 		info->gpio_npins = sc->sc_npins;
300 		break;
301 	case GPIOPINREAD:
302 		op = (struct gpio_pin_op *)data;
303 
304 		pin = op->gp_pin;
305 		if (pin < 0 || pin >= sc->sc_npins)
306 			return (EINVAL);
307 
308 		/* return read value */
309 		op->gp_value = gpiobus_pin_read(gc, pin);
310 		break;
311 	case GPIOPINWRITE:
312 		op = (struct gpio_pin_op *)data;
313 
314 		pin = op->gp_pin;
315 		if (pin < 0 || pin >= sc->sc_npins)
316 			return (EINVAL);
317 		if (sc->sc_pins[pin].pin_mapped)
318 			return (EBUSY);
319 
320 		value = op->gp_value;
321 		if (value != GPIO_PIN_LOW && value != GPIO_PIN_HIGH)
322 			return (EINVAL);
323 
324 		gpiobus_pin_write(gc, pin, value);
325 		/* return old value */
326 		op->gp_value = sc->sc_pins[pin].pin_state;
327 		/* update current value */
328 		sc->sc_pins[pin].pin_state = value;
329 		break;
330 	case GPIOPINTOGGLE:
331 		op = (struct gpio_pin_op *)data;
332 
333 		pin = op->gp_pin;
334 		if (pin < 0 || pin >= sc->sc_npins)
335 			return (EINVAL);
336 		if (sc->sc_pins[pin].pin_mapped)
337 			return (EBUSY);
338 
339 		value = (sc->sc_pins[pin].pin_state == GPIO_PIN_LOW ?
340 		    GPIO_PIN_HIGH : GPIO_PIN_LOW);
341 		gpiobus_pin_write(gc, pin, value);
342 		/* return old value */
343 		op->gp_value = sc->sc_pins[pin].pin_state;
344 		/* update current value */
345 		sc->sc_pins[pin].pin_state = value;
346 		break;
347 	case GPIOPINCTL:
348 		ctl = (struct gpio_pin_ctl *)data;
349 
350 		pin = ctl->gp_pin;
351 		if (pin < 0 || pin >= sc->sc_npins)
352 			return (EINVAL);
353 		if (sc->sc_pins[pin].pin_mapped)
354 			return (EBUSY);
355 
356 		flags = ctl->gp_flags;
357 		/* check that the controller supports all requested flags */
358 		if ((flags & sc->sc_pins[pin].pin_caps) != flags)
359 			return (ENODEV);
360 
361 		ctl->gp_caps = sc->sc_pins[pin].pin_caps;
362 		/* return old value */
363 		ctl->gp_flags = sc->sc_pins[pin].pin_flags;
364 		if (flags > 0) {
365 			gpiobus_pin_ctl(gc, pin, flags);
366 			/* update current value */
367 			sc->sc_pins[pin].pin_flags = flags;
368 		}
369 		break;
370 	default:
371 		return (ENOTTY);
372 	}
373 
374 	return (0);
375 }
376