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/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_DEFAULT 0 /* default index of SCL pin on gpiobus */ 52 #define SDA_PIN_DEFAULT 1 53 54 struct gpioiic_softc 55 { 56 device_t sc_dev; 57 device_t sc_busdev; 58 struct cdev *sc_leddev; 59 int scl_pin; 60 int sda_pin; 61 }; 62 63 static int gpioiic_probe(device_t); 64 static int gpioiic_attach(device_t); 65 66 /* iicbb interface */ 67 static void gpioiic_reset_bus(device_t); 68 static int gpioiic_callback(device_t, int, caddr_t); 69 static void gpioiic_setsda(device_t, int); 70 static void gpioiic_setscl(device_t, int); 71 static int gpioiic_getsda(device_t); 72 static int gpioiic_getscl(device_t); 73 static int gpioiic_reset(device_t, u_char, u_char, u_char *); 74 75 76 static int 77 gpioiic_probe(device_t dev) 78 { 79 80 device_set_desc(dev, "GPIO I2C bit-banging driver"); 81 return (0); 82 } 83 84 static int 85 gpioiic_attach(device_t dev) 86 { 87 struct gpioiic_softc *sc = device_get_softc(dev); 88 device_t bitbang; 89 90 sc->sc_dev = dev; 91 sc->sc_busdev = device_get_parent(dev); 92 if (resource_int_value(device_get_name(dev), 93 device_get_unit(dev), "scl", &sc->scl_pin)) 94 sc->scl_pin = SCL_PIN_DEFAULT; 95 if (resource_int_value(device_get_name(dev), 96 device_get_unit(dev), "sda", &sc->sda_pin)) 97 sc->sda_pin = SDA_PIN_DEFAULT; 98 99 /* add generic bit-banging code */ 100 bitbang = device_add_child(dev, "iicbb", -1); 101 device_probe_and_attach(bitbang); 102 103 return (0); 104 } 105 106 /* 107 * Reset bus by setting SDA first and then SCL. 108 * Must always be called with gpio bus locked. 109 */ 110 static void 111 gpioiic_reset_bus(device_t dev) 112 { 113 struct gpioiic_softc *sc = device_get_softc(dev); 114 115 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 116 GPIO_PIN_INPUT); 117 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 118 GPIO_PIN_INPUT); 119 } 120 121 static int 122 gpioiic_callback(device_t dev, int index, caddr_t data) 123 { 124 struct gpioiic_softc *sc = device_get_softc(dev); 125 int error = 0; 126 127 switch (index) { 128 case IIC_REQUEST_BUS: 129 GPIOBUS_LOCK_BUS(sc->sc_busdev); 130 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 131 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 132 break; 133 case IIC_RELEASE_BUS: 134 GPIOBUS_LOCK_BUS(sc->sc_busdev); 135 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 136 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 137 break; 138 default: 139 error = EINVAL; 140 } 141 142 return(error); 143 } 144 145 static void 146 gpioiic_setsda(device_t dev, int val) 147 { 148 struct gpioiic_softc *sc = device_get_softc(dev); 149 150 if (val == 0) { 151 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0); 152 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 153 GPIO_PIN_OUTPUT); 154 } else { 155 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 156 GPIO_PIN_INPUT); 157 } 158 } 159 160 static void 161 gpioiic_setscl(device_t dev, int val) 162 { 163 struct gpioiic_softc *sc = device_get_softc(dev); 164 165 if (val == 0) { 166 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0); 167 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 168 GPIO_PIN_OUTPUT); 169 } else { 170 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 171 GPIO_PIN_INPUT); 172 } 173 } 174 175 static int 176 gpioiic_getscl(device_t dev) 177 { 178 struct gpioiic_softc *sc = device_get_softc(dev); 179 unsigned int val; 180 181 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 182 GPIO_PIN_INPUT); 183 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val); 184 185 return ((int)val); 186 } 187 188 static int 189 gpioiic_getsda(device_t dev) 190 { 191 struct gpioiic_softc *sc = device_get_softc(dev); 192 unsigned int val; 193 194 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 195 GPIO_PIN_INPUT); 196 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val); 197 198 return ((int)val); 199 } 200 201 static int 202 gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 203 { 204 struct gpioiic_softc *sc = device_get_softc(dev); 205 206 GPIOBUS_LOCK_BUS(sc->sc_busdev); 207 GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev); 208 209 gpioiic_reset_bus(sc->sc_dev); 210 211 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 212 GPIOBUS_UNLOCK_BUS(sc->sc_busdev); 213 214 return (IIC_ENOADDR); 215 } 216 217 static devclass_t gpioiic_devclass; 218 219 static device_method_t gpioiic_methods[] = { 220 /* Device interface */ 221 DEVMETHOD(device_probe, gpioiic_probe), 222 DEVMETHOD(device_attach, gpioiic_attach), 223 DEVMETHOD(device_detach, bus_generic_detach), 224 225 /* iicbb interface */ 226 DEVMETHOD(iicbb_callback, gpioiic_callback), 227 DEVMETHOD(iicbb_setsda, gpioiic_setsda), 228 DEVMETHOD(iicbb_setscl, gpioiic_setscl), 229 DEVMETHOD(iicbb_getsda, gpioiic_getsda), 230 DEVMETHOD(iicbb_getscl, gpioiic_getscl), 231 DEVMETHOD(iicbb_reset, gpioiic_reset), 232 233 { 0, 0 } 234 }; 235 236 static driver_t gpioiic_driver = { 237 "gpioiic", 238 gpioiic_methods, 239 sizeof(struct gpioiic_softc), 240 }; 241 242 DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0); 243 DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0); 244 MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 245 MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1); 246