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("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/bus.h> 34 #include <sys/conf.h> 35 #include <sys/kernel.h> 36 #include <sys/module.h> 37 38 #include <sys/gpio.h> 39 #include "gpiobus_if.h" 40 41 #include <dev/iicbus/iiconf.h> 42 #include <dev/iicbus/iicbus.h> 43 44 #include "iicbb_if.h" 45 46 #define SCL_PIN_DEFAULT 0 /* default index of SCL pin on gpiobus */ 47 #define SDA_PIN_DEFAULT 1 48 49 struct gpioiic_softc 50 { 51 device_t sc_dev; 52 device_t sc_busdev; 53 int scl_pin; 54 int sda_pin; 55 }; 56 57 static int gpioiic_probe(device_t); 58 static int gpioiic_attach(device_t); 59 60 /* iicbb interface */ 61 static void gpioiic_reset_bus(device_t); 62 static int gpioiic_callback(device_t, int, caddr_t); 63 static void gpioiic_setsda(device_t, int); 64 static void gpioiic_setscl(device_t, int); 65 static int gpioiic_getsda(device_t); 66 static int gpioiic_getscl(device_t); 67 static int gpioiic_reset(device_t, u_char, u_char, u_char *); 68 69 70 static int 71 gpioiic_probe(device_t dev) 72 { 73 74 device_set_desc(dev, "GPIO I2C bit-banging driver"); 75 76 return (0); 77 } 78 79 static int 80 gpioiic_attach(device_t dev) 81 { 82 struct gpioiic_softc *sc = device_get_softc(dev); 83 device_t bitbang; 84 85 sc->sc_dev = dev; 86 sc->sc_busdev = device_get_parent(dev); 87 if (resource_int_value(device_get_name(dev), 88 device_get_unit(dev), "scl", &sc->scl_pin)) 89 sc->scl_pin = SCL_PIN_DEFAULT; 90 if (resource_int_value(device_get_name(dev), 91 device_get_unit(dev), "sda", &sc->sda_pin)) 92 sc->sda_pin = SDA_PIN_DEFAULT; 93 94 /* add generic bit-banging code */ 95 bitbang = device_add_child(dev, "iicbb", -1); 96 device_probe_and_attach(bitbang); 97 98 return (0); 99 } 100 101 /* 102 * Reset bus by setting SDA first and then SCL. 103 * Must always be called with gpio bus locked. 104 */ 105 static void 106 gpioiic_reset_bus(device_t dev) 107 { 108 struct gpioiic_softc *sc = device_get_softc(dev); 109 110 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 111 GPIO_PIN_INPUT); 112 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 113 GPIO_PIN_INPUT); 114 } 115 116 static int 117 gpioiic_callback(device_t dev, int index, caddr_t data) 118 { 119 struct gpioiic_softc *sc = device_get_softc(dev); 120 int error = 0; 121 122 switch (index) { 123 case IIC_REQUEST_BUS: 124 GPIOBUS_LOCK_BUS(sc->sc_busdev); 125 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 126 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 127 break; 128 case IIC_RELEASE_BUS: 129 GPIOBUS_LOCK_BUS(sc->sc_busdev); 130 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 131 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 132 break; 133 default: 134 error = EINVAL; 135 } 136 137 return (error); 138 } 139 140 static void 141 gpioiic_setsda(device_t dev, int val) 142 { 143 struct gpioiic_softc *sc = device_get_softc(dev); 144 145 if (val == 0) { 146 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0); 147 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 148 GPIO_PIN_OUTPUT); 149 } else { 150 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 151 GPIO_PIN_INPUT); 152 } 153 } 154 155 static void 156 gpioiic_setscl(device_t dev, int val) 157 { 158 struct gpioiic_softc *sc = device_get_softc(dev); 159 160 if (val == 0) { 161 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0); 162 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 163 GPIO_PIN_OUTPUT); 164 } else { 165 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 166 GPIO_PIN_INPUT); 167 } 168 } 169 170 static int 171 gpioiic_getscl(device_t dev) 172 { 173 struct gpioiic_softc *sc = device_get_softc(dev); 174 unsigned int val; 175 176 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 177 GPIO_PIN_INPUT); 178 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val); 179 180 return ((int)val); 181 } 182 183 static int 184 gpioiic_getsda(device_t dev) 185 { 186 struct gpioiic_softc *sc = device_get_softc(dev); 187 unsigned int val; 188 189 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 190 GPIO_PIN_INPUT); 191 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val); 192 193 return ((int)val); 194 } 195 196 static int 197 gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 198 { 199 struct gpioiic_softc *sc = device_get_softc(dev); 200 201 GPIOBUS_LOCK_BUS(sc->sc_busdev); 202 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 203 204 gpioiic_reset_bus(sc->sc_dev); 205 206 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 207 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 208 209 return (IIC_ENOADDR); 210 } 211 212 static devclass_t gpioiic_devclass; 213 214 static device_method_t gpioiic_methods[] = { 215 /* Device interface */ 216 DEVMETHOD(device_probe, gpioiic_probe), 217 DEVMETHOD(device_attach, gpioiic_attach), 218 DEVMETHOD(device_detach, bus_generic_detach), 219 220 /* iicbb interface */ 221 DEVMETHOD(iicbb_callback, gpioiic_callback), 222 DEVMETHOD(iicbb_setsda, gpioiic_setsda), 223 DEVMETHOD(iicbb_setscl, gpioiic_setscl), 224 DEVMETHOD(iicbb_getsda, gpioiic_getsda), 225 DEVMETHOD(iicbb_getscl, gpioiic_getscl), 226 DEVMETHOD(iicbb_reset, gpioiic_reset), 227 228 { 0, 0 } 229 }; 230 231 static driver_t gpioiic_driver = { 232 "gpioiic", 233 gpioiic_methods, 234 sizeof(struct gpioiic_softc), 235 }; 236 237 DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0); 238 DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0); 239 MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 240 MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1); 241