gpioow.c revision 1.16 
1/* $NetBSD: gpioow.c,v 1.16 2019/11/30 23:04:12 ad 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 1.16 2019/11/30 23:04:12 ad 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#include <sys/module.h>
32
33#include <dev/gpio/gpiovar.h>
34
35#include <dev/onewire/onewirevar.h>
36
37#include "ioconf.h"
38
39#define GPIOOW_NPINS		1
40#define GPIOOW_PIN_DATA		0
41
42struct gpioow_softc {
43	void *			sc_gpio;
44	struct gpio_pinmap	sc_map;
45	int			_map[GPIOOW_NPINS];
46
47	struct onewire_bus	sc_ow_bus;
48	device_t		sc_ow_dev;
49
50	int			sc_data;
51	int			sc_dying;
52};
53
54int	gpioow_match(device_t, cfdata_t, void *);
55void	gpioow_attach(device_t, device_t, void *);
56int	gpioow_detach(device_t, int);
57int	gpioow_activate(device_t, enum devact);
58
59int	gpioow_ow_reset(void *);
60int	gpioow_ow_read_bit(void *);
61void	gpioow_ow_write_bit(void *, int);
62
63void	gpioow_bb_rx(void *);
64void	gpioow_bb_tx(void *);
65int	gpioow_bb_get(void *);
66void	gpioow_bb_set(void *, int);
67
68CFATTACH_DECL_NEW(gpioow, sizeof(struct gpioow_softc),
69	gpioow_match, gpioow_attach, gpioow_detach, gpioow_activate);
70
71static const struct onewire_bbops gpioow_bbops = {
72	gpioow_bb_rx,
73	gpioow_bb_tx,
74	gpioow_bb_get,
75	gpioow_bb_set
76};
77
78int
79gpioow_match(device_t parent, cfdata_t cf, void *aux)
80{
81	struct gpio_attach_args *ga = aux;
82
83	if (strcmp(ga->ga_dvname, cf->cf_name))
84		return 0;
85
86	if (ga->ga_offset == -1)
87		return 0;
88
89	/* Check that we have enough pins */
90	if (gpio_npins(ga->ga_mask) != GPIOOW_NPINS) {
91		aprint_debug("%s: invalid pin mask 0x%02x\n", cf->cf_name,
92		    ga->ga_mask);
93		return 0;
94	}
95	return 1;
96}
97
98void
99gpioow_attach(device_t parent, device_t self, void *aux)
100{
101	struct gpioow_softc *sc = device_private(self);
102	struct gpio_attach_args *ga = aux;
103	struct onewirebus_attach_args oba;
104	int caps;
105
106	/* Map pins */
107	sc->sc_gpio = ga->ga_gpio;
108	sc->sc_map.pm_map = sc->_map;
109	if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
110	    &sc->sc_map)) {
111		aprint_error(": can't map pins\n");
112		goto finish;
113	}
114
115	/* Configure data pin */
116	caps = gpio_pin_caps(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA);
117	if (!(caps & GPIO_PIN_OUTPUT)) {
118		aprint_error(": data pin is unable to drive output\n");
119		gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
120		goto finish;
121	}
122	if (!(caps & GPIO_PIN_INPUT)) {
123		aprint_error(": data pin is unable to read input\n");
124		gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
125		goto finish;
126	}
127	aprint_normal(": DATA[%d]", sc->sc_map.pm_map[GPIOOW_PIN_DATA]);
128	sc->sc_data = GPIO_PIN_OUTPUT;
129	if (caps & GPIO_PIN_OPENDRAIN) {
130		aprint_normal(" open-drain");
131		sc->sc_data |= GPIO_PIN_OPENDRAIN;
132	} else if ((caps & GPIO_PIN_PUSHPULL) && (caps & GPIO_PIN_TRISTATE)) {
133		aprint_normal(" push-pull tri-state");
134		sc->sc_data |= GPIO_PIN_PUSHPULL;
135	}
136	if (caps & GPIO_PIN_PULLUP) {
137		aprint_normal(" pull-up");
138		sc->sc_data |= GPIO_PIN_PULLUP;
139	}
140	gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA, sc->sc_data);
141
142	aprint_normal("\n");
143
144	/* Attach 1-Wire bus */
145	sc->sc_ow_bus.bus_cookie = sc;
146	sc->sc_ow_bus.bus_reset = gpioow_ow_reset;
147	sc->sc_ow_bus.bus_read_bit = gpioow_ow_read_bit;
148	sc->sc_ow_bus.bus_write_bit = gpioow_ow_write_bit;
149
150	memset(&oba, 0, sizeof(oba));
151	oba.oba_bus = &sc->sc_ow_bus;
152	sc->sc_ow_dev = config_found(self, &oba, onewirebus_print);
153
154	if (!pmf_device_register(self, NULL, NULL))
155		aprint_error("%s: could not establish power handler\n",
156		    device_xname(self));
157finish:
158	return;
159}
160
161int
162gpioow_detach(device_t self, int flags)
163{
164	struct gpioow_softc *sc = device_private(self);
165	int rv = 0;
166
167	if (sc->sc_ow_dev != NULL)
168		rv = config_detach(sc->sc_ow_dev, flags);
169
170	if (!rv) {
171		gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
172		pmf_device_deregister(self);
173	}
174	return rv;
175}
176
177int
178gpioow_activate(device_t self, enum devact act)
179{
180	struct gpioow_softc *sc = device_private(self);
181
182	switch (act) {
183	case DVACT_DEACTIVATE:
184		sc->sc_dying = 1;
185		return 0;
186	default:
187		return EOPNOTSUPP;
188	}
189}
190
191int
192gpioow_ow_reset(void *arg)
193{
194	return (onewire_bb_reset(&gpioow_bbops, arg));
195}
196
197int
198gpioow_ow_read_bit(void *arg)
199{
200	return (onewire_bb_read_bit(&gpioow_bbops, arg));
201}
202
203void
204gpioow_ow_write_bit(void *arg, int value)
205{
206	onewire_bb_write_bit(&gpioow_bbops, arg, value);
207}
208
209void
210gpioow_bb_rx(void *arg)
211{
212	struct gpioow_softc *sc = arg;
213	int data = sc->sc_data;
214
215	data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
216	data |= GPIO_PIN_INPUT;
217	if (data & GPIO_PIN_PUSHPULL)
218		data |= GPIO_PIN_TRISTATE;
219	if (sc->sc_data != data) {
220		sc->sc_data = data;
221		gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
222		    sc->sc_data);
223	}
224}
225
226void
227gpioow_bb_tx(void *arg)
228{
229	struct gpioow_softc *sc = arg;
230	int data = sc->sc_data;
231
232	data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
233	data |= GPIO_PIN_OUTPUT;
234	if (sc->sc_data != data) {
235		sc->sc_data = data;
236		gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
237		    sc->sc_data);
238	}
239}
240
241int
242gpioow_bb_get(void *arg)
243{
244	struct gpioow_softc *sc = arg;
245
246	return (gpio_pin_read(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA) ==
247	    GPIO_PIN_HIGH ? 1 : 0);
248}
249
250void
251gpioow_bb_set(void *arg, int value)
252{
253	struct gpioow_softc *sc = arg;
254
255	gpio_pin_write(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
256	    value ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
257}
258
259MODULE(MODULE_CLASS_DRIVER, gpioow, "gpio,onewire");
260
261#ifdef _MODULE
262#include "ioconf.c"
263#endif
264
265static int
266gpioow_modcmd(modcmd_t cmd, void *opaque)
267{
268	int error;
269
270	error = 0;
271	switch (cmd) {
272	case MODULE_CMD_INIT:
273#ifdef _MODULE
274		error = config_init_component(cfdriver_ioconf_gpioow,
275		    cfattach_ioconf_gpioow, cfdata_ioconf_gpioow);
276		if (error)
277			aprint_error("%s: unable to init component\n",
278			    gpioow_cd.cd_name);
279#endif
280		break;
281	case MODULE_CMD_FINI:
282#ifdef _MODULE
283		config_fini_component(cfdriver_ioconf_gpioow,
284		    cfattach_ioconf_gpioow, cfdata_ioconf_gpioow);
285#endif
286		break;
287	default:
288		error = ENOTTY;
289	}
290	return error;
291}
292