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 "opt_platform.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/bus.h> 36 #include <sys/gpio.h> 37 #include <sys/kernel.h> 38 #include <sys/module.h> 39 40 #ifdef FDT 41 #include <dev/fdt/fdt_common.h> 42 #include <dev/ofw/ofw_bus.h> 43 #endif 44 45 #include <dev/gpio/gpiobusvar.h> 46 #include <dev/iicbus/iiconf.h> 47 #include <dev/iicbus/iicbus.h> 48 49 #include "gpiobus_if.h" 50 #include "iicbb_if.h" 51 52 #define GPIOIIC_SCL_DFLT 0 53 #define GPIOIIC_SDA_DFLT 1 54 #define GPIOIIC_MIN_PINS 2 55 56 struct gpioiic_softc 57 { 58 device_t sc_dev; 59 device_t sc_busdev; 60 int scl_pin; 61 int sda_pin; 62 }; 63 64 static int gpioiic_probe(device_t); 65 static int gpioiic_attach(device_t); 66 67 /* iicbb interface */ 68 static void gpioiic_reset_bus(device_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 static int 76 gpioiic_probe(device_t dev) 77 { 78 struct gpiobus_ivar *devi; 79 80 #ifdef FDT 81 if (!ofw_bus_status_okay(dev)) 82 return (ENXIO); 83 if (!ofw_bus_is_compatible(dev, "gpioiic")) 84 return (ENXIO); 85 #endif 86 devi = GPIOBUS_IVAR(dev); 87 if (devi->npins < GPIOIIC_MIN_PINS) { 88 device_printf(dev, 89 "gpioiic needs at least %d GPIO pins (only %d given).\n", 90 GPIOIIC_MIN_PINS, devi->npins); 91 return (ENXIO); 92 } 93 device_set_desc(dev, "GPIO I2C bit-banging driver"); 94 95 return (BUS_PROBE_DEFAULT); 96 } 97 98 static int 99 gpioiic_attach(device_t dev) 100 { 101 device_t bitbang; 102 #ifdef FDT 103 phandle_t node; 104 pcell_t pin; 105 #endif 106 struct gpiobus_ivar *devi; 107 struct gpioiic_softc *sc; 108 109 sc = device_get_softc(dev); 110 sc->sc_dev = dev; 111 sc->sc_busdev = device_get_parent(dev); 112 if (resource_int_value(device_get_name(dev), 113 device_get_unit(dev), "scl", &sc->scl_pin)) 114 sc->scl_pin = GPIOIIC_SCL_DFLT; 115 if (resource_int_value(device_get_name(dev), 116 device_get_unit(dev), "sda", &sc->sda_pin)) 117 sc->sda_pin = GPIOIIC_SDA_DFLT; 118 119 #ifdef FDT 120 if ((node = ofw_bus_get_node(dev)) == -1) 121 return (ENXIO); 122 if (OF_getencprop(node, "scl", &pin, sizeof(pin)) > 0) 123 sc->scl_pin = (int)pin; 124 if (OF_getencprop(node, "sda", &pin, sizeof(pin)) > 0) 125 sc->sda_pin = (int)pin; 126 #endif 127 128 if (sc->scl_pin < 0 || sc->scl_pin > 1) 129 sc->scl_pin = GPIOIIC_SCL_DFLT; 130 if (sc->sda_pin < 0 || sc->sda_pin > 1) 131 sc->sda_pin = GPIOIIC_SDA_DFLT; 132 133 devi = GPIOBUS_IVAR(dev); 134 device_printf(dev, "SCL pin: %d, SDA pin: %d\n", 135 devi->pins[sc->scl_pin], devi->pins[sc->sda_pin]); 136 137 /* add generic bit-banging code */ 138 bitbang = device_add_child(dev, "iicbb", -1); 139 device_probe_and_attach(bitbang); 140 141 return (0); 142 } 143 144 /* 145 * Reset bus by setting SDA first and then SCL. 146 * Must always be called with gpio bus locked. 147 */ 148 static void 149 gpioiic_reset_bus(device_t dev) 150 { 151 struct gpioiic_softc *sc = device_get_softc(dev); 152 153 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 154 GPIO_PIN_INPUT); 155 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 156 GPIO_PIN_INPUT); 157 } 158 159 static void 160 gpioiic_setsda(device_t dev, int val) 161 { 162 struct gpioiic_softc *sc = device_get_softc(dev); 163 164 if (val == 0) { 165 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0); 166 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 167 GPIO_PIN_OUTPUT); 168 } else { 169 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 170 GPIO_PIN_INPUT); 171 } 172 } 173 174 static void 175 gpioiic_setscl(device_t dev, int val) 176 { 177 struct gpioiic_softc *sc = device_get_softc(dev); 178 179 if (val == 0) { 180 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0); 181 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 182 GPIO_PIN_OUTPUT); 183 } else { 184 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 185 GPIO_PIN_INPUT); 186 } 187 } 188 189 static int 190 gpioiic_getscl(device_t dev) 191 { 192 struct gpioiic_softc *sc = device_get_softc(dev); 193 unsigned int val; 194 195 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 196 GPIO_PIN_INPUT); 197 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val); 198 199 return ((int)val); 200 } 201 202 static int 203 gpioiic_getsda(device_t dev) 204 { 205 struct gpioiic_softc *sc = device_get_softc(dev); 206 unsigned int val; 207 208 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 209 GPIO_PIN_INPUT); 210 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val); 211 212 return ((int)val); 213 } 214 215 static int 216 gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 217 { 218 struct gpioiic_softc *sc; 219 220 sc = device_get_softc(dev); 221 gpioiic_reset_bus(sc->sc_dev); 222 223 return (IIC_ENOADDR); 224 } 225 226 #ifdef FDT 227 static phandle_t 228 gpioiic_get_node(device_t bus, device_t dev) 229 { 230 231 /* We only have one child, the iicbb, which needs our own node. */ 232 return (ofw_bus_get_node(bus)); 233 } 234 #endif 235 236 static devclass_t gpioiic_devclass; 237 238 static device_method_t gpioiic_methods[] = { 239 /* Device interface */ 240 DEVMETHOD(device_probe, gpioiic_probe), 241 DEVMETHOD(device_attach, gpioiic_attach), 242 DEVMETHOD(device_detach, bus_generic_detach), 243 244 /* iicbb interface */ 245 DEVMETHOD(iicbb_setsda, gpioiic_setsda), 246 DEVMETHOD(iicbb_setscl, gpioiic_setscl), 247 DEVMETHOD(iicbb_getsda, gpioiic_getsda), 248 DEVMETHOD(iicbb_getscl, gpioiic_getscl), 249 DEVMETHOD(iicbb_reset, gpioiic_reset), 250 251 #ifdef FDT 252 /* OFW bus interface */ 253 DEVMETHOD(ofw_bus_get_node, gpioiic_get_node), 254 #endif 255 256 DEVMETHOD_END 257 }; 258 259 static driver_t gpioiic_driver = { 260 "gpioiic", 261 gpioiic_methods, 262 sizeof(struct gpioiic_softc), 263 }; 264 265 DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0); 266 DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0); 267 MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 268 MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1); 269