sys/dev/gpio/gpioow.c

   1 /* $NetBSD: gpioow.c,v 1.11 2009/08/08 10:38:17 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 1.11 2009/08/08 10:38:17 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
  39 struct 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
  51 int     gpioow_match(device_t, cfdata_t, void *);
  52 void    gpioow_attach(device_t, device_t, void *);
  53 int     gpioow_detach(device_t, int);
  54 int     gpioow_activate(device_t, enum devact);
  55
  56 int     gpioow_ow_reset(void *);
  57 int     gpioow_ow_bit(void *, int);
  58
  59 void    gpioow_bb_rx(void *);
  60 void    gpioow_bb_tx(void *);
  61 int     gpioow_bb_get(void *);
  62 void    gpioow_bb_set(void *, int);
  63
  64 CFATTACH_DECL_NEW(gpioow, sizeof(struct gpioow_softc),
  65         gpioow_match, gpioow_attach, gpioow_detach, gpioow_activate);
  66
  67 extern struct cfdriver gpioow_cd;
  68
  69 static const struct onewire_bbops gpioow_bbops = {
  70         gpioow_bb_rx,
  71         gpioow_bb_tx,
  72         gpioow_bb_get,
  73         gpioow_bb_set
  74 };
  75
  76 int
  77 gpioow_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
  96 void
  97 gpioow_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         if (!pmf_device_register(self, NULL, NULL))
 150                 aprint_error("%s: could not establish power handler\n",
 151                     device_xname(self));
 152         return;
 153
 154 fail:
 155         gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
 156 }
 157
 158 int
 159 gpioow_detach(device_t self, int flags)
 160 {
 161         struct gpioow_softc *sc = device_private(self);
 162         int rv = 0;
 163
 164         if (sc->sc_ow_dev != NULL)
 165                 rv = config_detach(sc->sc_ow_dev, flags);
 166
 167         if (!rv) {
 168                 gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
 169                 pmf_device_deregister(self);
 170         }
 171         return rv;
 172 }
 173
 174 int
 175 gpioow_activate(device_t self, enum devact act)
 176 {
 177         struct gpioow_softc *sc = device_private(self);
 178
 179         switch (act) {
 180         case DVACT_DEACTIVATE:
 181                 sc->sc_dying = 1;
 182                 return 0;
 183         default:
 184                 return EOPNOTSUPP;
 185         }
 186 }
 187
 188 int
 189 gpioow_ow_reset(void *arg)
 190 {
 191         return (onewire_bb_reset(&gpioow_bbops, arg));
 192 }
 193
 194 int
 195 gpioow_ow_bit(void *arg, int value)
 196 {
 197         return (onewire_bb_bit(&gpioow_bbops, arg, value));
 198 }
 199
 200 void
 201 gpioow_bb_rx(void *arg)
 202 {
 203         struct gpioow_softc *sc = arg;
 204         int data = sc->sc_data;
 205
 206         data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
 207         data |= GPIO_PIN_INPUT;
 208         if (data & GPIO_PIN_PUSHPULL)
 209                 data |= GPIO_PIN_TRISTATE;
 210         if (sc->sc_data != data) {
 211                 sc->sc_data = data;
 212                 gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
 213                     sc->sc_data);
 214         }
 215 }
 216
 217 void
 218 gpioow_bb_tx(void *arg)
 219 {
 220         struct gpioow_softc *sc = arg;
 221         int data = sc->sc_data;
 222
 223         data &= ~(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
 224         data |= GPIO_PIN_OUTPUT;
 225         if (sc->sc_data != data) {
 226                 sc->sc_data = data;
 227                 gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
 228                     sc->sc_data);
 229         }
 230 }
 231
 232 int
 233 gpioow_bb_get(void *arg)
 234 {
 235         struct gpioow_softc *sc = arg;
 236
 237         return (gpio_pin_read(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA) ==
 238             GPIO_PIN_HIGH ? 1 : 0);
 239 }
 240
 241 void
 242 gpioow_bb_set(void *arg, int value)
 243 {
 244         struct gpioow_softc *sc = arg;
 245
 246         gpio_pin_write(sc->sc_gpio, &sc->sc_map, GPIOOW_PIN_DATA,
 247             value ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
 248 }