gpioow.c revision 1.9 
1/* $NetBSD: gpioow.c,v 1.9 2009/08/03 17:24:40 mbalmer Exp $ */
2/*	$OpenBSD: gpioow.c,v 1.1 2006/03/04 16:27:03 grange Exp $	*/
3
4/*
5 * Copyright (c) 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: gpioow.c,v 1.9 2009/08/03 17:24:40 mbalmer Exp $");
22
23/*
24 * 1-Wire bus bit-banging through GPIO pin.
25 */
26
27#include <sys/param.h>
28#include <sys/systm.h>
29#include <sys/device.h>
30#include <sys/gpio.h>
31
32#include <dev/gpio/gpiovar.h>
33
34#include <dev/onewire/onewirevar.h>
35
36#define GPIOOW_NPINS		1
37#define GPIOOW_PIN_DATA		0
38
39struct gpioow_softc {
40	void *			sc_gpio;
41	struct gpio_pinmap	sc_map;
42	int			__map[GPIOOW_NPINS];
43
44	struct onewire_bus	sc_ow_bus;
45	device_t		sc_ow_dev;
46
47	int			sc_data;
48	int			sc_dying;
49};
50
51int	gpioow_match(device_t, cfdata_t, void *);
52void	gpioow_attach(device_t, device_t, void *);
53int	gpioow_detach(device_t, int);
54int	gpioow_activate(device_t, enum devact);
55
56int	gpioow_ow_reset(void *);
57int	gpioow_ow_bit(void *, int);
58
59void	gpioow_bb_rx(void *);
60void	gpioow_bb_tx(void *);
61int	gpioow_bb_get(void *);
62void	gpioow_bb_set(void *, int);
63
64CFATTACH_DECL_NEW(gpioow, sizeof(struct gpioow_softc),
65	gpioow_match, gpioow_attach, gpioow_detach, gpioow_activate);
66
67extern struct cfdriver gpioow_cd;
68
69static const struct onewire_bbops gpioow_bbops = {
70	gpioow_bb_rx,
71	gpioow_bb_tx,
72	gpioow_bb_get,
73	gpioow_bb_set
74};
75
76int
77gpioow_match(device_t parent, cfdata_t cf, void *aux)
78{
79	struct gpio_attach_args *ga = aux;
80
81	if (strcmp(ga->ga_dvname, cf->cf_name))
82		return 0;
83
84	if (ga->ga_offset == -1)
85		return 0;
86
87	/* Check that we have enough pins */
88	if (gpio_npins(ga->ga_mask) != GPIOOW_NPINS) {
89		aprint_debug("%s: invalid pin mask 0x%02x/n", cf->cf_name,
90		    ga->ga_mask);
91		return 0;
92	}
93	return 1;
94}
95
96void
97gpioow_attach(device_t parent, device_t self, void *aux)
98{
99	struct gpioow_softc *sc = device_private(self);
100	struct gpio_attach_args *ga = aux;
101	struct onewirebus_attach_args oba;
102	int caps;
103
104	/* Map pins */
105	sc->sc_gpio = ga->ga_gpio;
106	sc->sc_map.pm_map = sc->__map;
107	if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
108	    &sc->sc_map)) {
109		aprint_error(": can't map pins\n");
110		return;
111	}
112
113	/* Configure data pin */
114	caps = gpio_pin_caps(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA);
115	if (!(caps & GPIO_PIN_OUTPUT)) {
116		aprint_error(": data pin is unable to drive output\n");
117		goto fail;
118	}
119	if (!(caps & GPIO_PIN_INPUT)) {
120		aprint_error(": data pin is unable to read input\n");
121		goto fail;
122	}
123	aprint_normal(": DATA[%d]", sc->sc_map.pm_map[GPIOOW_PIN_DATA]);
124	sc->sc_data = GPIO_PIN_OUTPUT;
125	if (caps & GPIO_PIN_OPENDRAIN) {
126		aprint_normal(" open-drain");
127		sc->sc_data |= GPIO_PIN_OPENDRAIN;
128	} else if ((caps & GPIO_PIN_PUSHPULL) && (caps & GPIO_PIN_TRISTATE)) {
129		aprint_normal(" push-pull tri-state");
130		sc->sc_data |= GPIO_PIN_PUSHPULL;
131	}
132	if (caps & GPIO_PIN_PULLUP) {
133		aprint_normal(" pull-up");
134		sc->sc_data |= GPIO_PIN_PULLUP;
135	}
136	gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA, sc->sc_data);
137
138	aprint_normal("\n");
139
140	/* Attach 1-Wire bus */
141	sc->sc_ow_bus.bus_cookie = sc;
142	sc->sc_ow_bus.bus_reset = gpioow_ow_reset;
143	sc->sc_ow_bus.bus_bit = gpioow_ow_bit;
144
145	memset(&oba, 0, sizeof(oba));
146	oba.oba_bus = &sc->sc_ow_bus;
147	sc->sc_ow_dev = config_found(self, &oba, onewirebus_print);
148
149	return;
150
151fail:
152	gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
153}
154
155int
156gpioow_detach(device_t self, int flags)
157{
158	struct gpioow_softc *sc = device_private(self);
159	int rv = 0;
160
161	gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
162
163	if (sc->sc_ow_dev != NULL)
164		rv = config_detach(sc->sc_ow_dev, flags);
165
166	return rv;
167}
168
169int
170gpioow_activate(device_t self, enum devact act)
171{
172	struct gpioow_softc *sc = device_private(self);
173	int rv = 0;
174
175	switch (act) {
176	case DVACT_ACTIVATE:
177		return EOPNOTSUPP;
178	case DVACT_DEACTIVATE:
179		sc->sc_dying = 1;
180		if (sc->sc_ow_dev != NULL)
181			rv = config_deactivate(sc->sc_ow_dev);
182		break;
183	}
184	return rv;
185}
186
187int
188gpioow_ow_reset(void *arg)
189{
190	return (onewire_bb_reset(&gpioow_bbops, arg));
191}
192
193int
194gpioow_ow_bit(void *arg, int value)
195{
196	return (onewire_bb_bit(&gpioow_bbops, arg, value));
197}
198
199void
200gpioow_bb_rx(void *arg)
201{
202	struct gpioow_softc *sc = arg;
203	int data = sc->sc_data;
204
205	data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
206	data |= GPIO_PIN_INPUT;
207	if (data & GPIO_PIN_PUSHPULL)
208		data |= GPIO_PIN_TRISTATE;
209	if (sc->sc_data != data) {
210		sc->sc_data = data;
211		gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
212		    sc->sc_data);
213	}
214}
215
216void
217gpioow_bb_tx(void *arg)
218{
219	struct gpioow_softc *sc = arg;
220	int data = sc->sc_data;
221
222	data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
223	data |= GPIO_PIN_OUTPUT;
224	if (sc->sc_data != data) {
225		sc->sc_data = data;
226		gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
227		    sc->sc_data);
228	}
229}
230
231int
232gpioow_bb_get(void *arg)
233{
234	struct gpioow_softc *sc = arg;
235
236	return (gpio_pin_read(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA) ==
237	    GPIO_PIN_HIGH ? 1 : 0);
238}
239
240void
241gpioow_bb_set(void *arg, int value)
242{
243	struct gpioow_softc *sc = arg;
244
245	gpio_pin_write(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
246	    value ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
247}
248