gpioiic.c revision 213277
1/*- 2 * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org> 3 * Copyright (c) 2010 Luiz Otavio O Souza 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/sys/dev/gpio/gpioiic.c 213277 2010-09-29 20:53:33Z gonzo $"); 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/bio.h> 34#include <sys/bus.h> 35#include <sys/conf.h> 36#include <sys/kernel.h> 37#include <sys/kthread.h> 38#include <sys/lock.h> 39#include <sys/malloc.h> 40#include <sys/module.h> 41#include <sys/mutex.h> 42 43#include <sys/gpio.h> 44#include "gpiobus_if.h" 45 46#include <dev/iicbus/iiconf.h> 47#include <dev/iicbus/iicbus.h> 48 49#include "iicbb_if.h" 50 51#define SCL_PIN 0 /* gpiobus mapped pin 6 */ 52#define SDA_PIN 1 /* gpiobus mapped pin 7 */ 53 54struct gpioiic_softc 55{ 56 device_t sc_dev; 57 device_t sc_busdev; 58 struct mtx sc_mtx; 59 struct cdev *sc_leddev; 60}; 61 62static int gpioiic_probe(device_t); 63static int gpioiic_attach(device_t); 64 65/* iicbb interface */ 66static void gpioiic_reset_bus(device_t); 67static int gpioiic_callback(device_t, int, caddr_t); 68static void gpioiic_setsda(device_t, int); 69static void gpioiic_setscl(device_t, int); 70static int gpioiic_getsda(device_t); 71static int gpioiic_getscl(device_t); 72static int gpioiic_reset(device_t, u_char, u_char, u_char *); 73 74 75static int 76gpioiic_probe(device_t dev) 77{ 78 79 device_set_desc(dev, "GPIO I2C bit-banging driver"); 80 return (0); 81} 82 83static int 84gpioiic_attach(device_t dev) 85{ 86 struct gpioiic_softc *sc = device_get_softc(dev); 87 device_t bitbang; 88 89 sc->sc_dev = dev; 90 sc->sc_busdev = device_get_parent(dev); 91 92 /* add generic bit-banging code */ 93 bitbang = device_add_child(dev, "iicbb", -1); 94 device_probe_and_attach(bitbang); 95 96 return (0); 97} 98 99/* 100 * Reset bus by setting SDA first and then SCL. 101 * Must always be called with gpio bus locked. 102 */ 103static void 104gpioiic_reset_bus(device_t dev) 105{ 106 struct gpioiic_softc *sc = device_get_softc(dev); 107 108 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SDA_PIN, 109 GPIO_PIN_INPUT); 110 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SCL_PIN, 111 GPIO_PIN_INPUT); 112} 113 114static int 115gpioiic_callback(device_t dev, int index, caddr_t data) 116{ 117 struct gpioiic_softc *sc = device_get_softc(dev); 118 int error = 0; 119 120 switch (index) { 121 case IIC_REQUEST_BUS: 122 GPIOBUS_LOCK_BUS(sc->sc_busdev); 123 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 124 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 125 break; 126 case IIC_RELEASE_BUS: 127 GPIOBUS_LOCK_BUS(sc->sc_busdev); 128 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 129 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 130 break; 131 default: 132 error = EINVAL; 133 } 134 135 return(error); 136} 137 138static void 139gpioiic_setsda(device_t dev, int val) 140{ 141 struct gpioiic_softc *sc = device_get_softc(dev); 142 143 GPIOBUS_LOCK_BUS(sc->sc_busdev); 144 if (val == 0) { 145 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, SDA_PIN, 0); 146 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SDA_PIN, 147 GPIO_PIN_OUTPUT); 148 } else { 149 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SDA_PIN, 150 GPIO_PIN_INPUT); 151 } 152 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 153} 154 155static void 156gpioiic_setscl(device_t dev, int val) 157{ 158 struct gpioiic_softc *sc = device_get_softc(dev); 159 160 GPIOBUS_LOCK_BUS(sc->sc_busdev); 161 if (val == 0) { 162 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, SCL_PIN, 0); 163 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SCL_PIN, 164 GPIO_PIN_OUTPUT); 165 } else { 166 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SCL_PIN, 167 GPIO_PIN_INPUT); 168 } 169 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 170} 171 172static int 173gpioiic_getscl(device_t dev) 174{ 175 struct gpioiic_softc *sc = device_get_softc(dev); 176 unsigned int val; 177 178 GPIOBUS_LOCK_BUS(sc->sc_busdev); 179 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SCL_PIN, 180 GPIO_PIN_INPUT); 181 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, SCL_PIN, &val); 182 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 183 184 return ((int)val); 185} 186 187static int 188gpioiic_getsda(device_t dev) 189{ 190 struct gpioiic_softc *sc = device_get_softc(dev); 191 unsigned int val; 192 193 GPIOBUS_LOCK_BUS(sc->sc_busdev); 194 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, SDA_PIN, 195 GPIO_PIN_INPUT); 196 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, SDA_PIN, &val); 197 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 198 199 return ((int)val); 200} 201 202static int 203gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 204{ 205 struct gpioiic_softc *sc = device_get_softc(dev); 206 207 GPIOBUS_LOCK_BUS(sc->sc_busdev); 208 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 209 210 gpioiic_reset_bus(sc->sc_dev); 211 212 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 213 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 214 215 return (IIC_ENOADDR); 216} 217 218static devclass_t gpioiic_devclass; 219 220static device_method_t gpioiic_methods[] = { 221 /* Device interface */ 222 DEVMETHOD(device_probe, gpioiic_probe), 223 DEVMETHOD(device_attach, gpioiic_attach), 224 DEVMETHOD(device_detach, bus_generic_detach), 225 226 /* iicbb interface */ 227 DEVMETHOD(iicbb_callback, gpioiic_callback), 228 DEVMETHOD(iicbb_setsda, gpioiic_setsda), 229 DEVMETHOD(iicbb_setscl, gpioiic_setscl), 230 DEVMETHOD(iicbb_getsda, gpioiic_getsda), 231 DEVMETHOD(iicbb_getscl, gpioiic_getscl), 232 DEVMETHOD(iicbb_reset, gpioiic_reset), 233 234 { 0, 0 } 235}; 236 237static driver_t gpioiic_driver = { 238 "gpioiic", 239 gpioiic_methods, 240 sizeof(struct gpioiic_softc), 241}; 242 243DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0); 244DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0); 245MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 246MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1); 247