gpioiic.c revision 273917
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 273917 2014-10-31 19:15:14Z loos $"); 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/conf.h> 37#include <sys/kernel.h> 38#include <sys/module.h> 39 40#include <sys/gpio.h> 41#include "gpiobus_if.h" 42 43#ifdef FDT 44#include <dev/ofw/ofw_bus.h> 45#include <dev/ofw/ofw_bus_subr.h> 46#include <dev/fdt/fdt_common.h> 47#endif 48 49#include <dev/gpio/gpiobusvar.h> 50 51#include <dev/iicbus/iiconf.h> 52#include <dev/iicbus/iicbus.h> 53 54#include "iicbb_if.h" 55 56#define SCL_PIN_DEFAULT 0 /* default index of SCL pin on gpiobus */ 57#define SDA_PIN_DEFAULT 1 58 59struct gpioiic_softc 60{ 61 device_t sc_dev; 62 device_t sc_busdev; 63 int scl_pin; 64 int sda_pin; 65}; 66 67static int gpioiic_probe(device_t); 68static int gpioiic_attach(device_t); 69 70/* iicbb interface */ 71static void gpioiic_reset_bus(device_t); 72static int gpioiic_callback(device_t, int, caddr_t); 73static void gpioiic_setsda(device_t, int); 74static void gpioiic_setscl(device_t, int); 75static int gpioiic_getsda(device_t); 76static int gpioiic_getscl(device_t); 77static int gpioiic_reset(device_t, u_char, u_char, u_char *); 78 79static int 80gpioiic_probe(device_t dev) 81{ 82 83#ifdef FDT 84 if (!ofw_bus_is_compatible(dev, "gpioiic")) 85 return (ENXIO); 86#endif 87 device_set_desc(dev, "GPIO I2C bit-banging driver"); 88 89 return (0); 90} 91 92static int 93gpioiic_attach(device_t dev) 94{ 95 device_t bitbang; 96#ifdef FDT 97 phandle_t node; 98 pcell_t pin; 99#endif 100 struct gpiobus_ivar *devi; 101 struct gpioiic_softc *sc; 102 103 sc = device_get_softc(dev); 104 sc->sc_dev = dev; 105 sc->sc_busdev = device_get_parent(dev); 106 if (resource_int_value(device_get_name(dev), 107 device_get_unit(dev), "scl", &sc->scl_pin)) 108 sc->scl_pin = SCL_PIN_DEFAULT; 109 if (resource_int_value(device_get_name(dev), 110 device_get_unit(dev), "sda", &sc->sda_pin)) 111 sc->sda_pin = SDA_PIN_DEFAULT; 112 113#ifdef FDT 114 if ((node = ofw_bus_get_node(dev)) == -1) 115 return (ENXIO); 116 if (OF_getencprop(node, "scl", &pin, sizeof(pin)) > 0) 117 sc->scl_pin = (int)pin; 118 if (OF_getencprop(node, "sda", &pin, sizeof(pin)) > 0) 119 sc->sda_pin = (int)pin; 120#endif 121 122 if (sc->scl_pin < 0 || sc->scl_pin > 1) 123 sc->scl_pin = SCL_PIN_DEFAULT; 124 if (sc->sda_pin < 0 || sc->sda_pin > 1) 125 sc->sda_pin = SDA_PIN_DEFAULT; 126 127 devi = GPIOBUS_IVAR(dev); 128 device_printf(dev, "SCL pin: %d, SDA pin: %d\n", 129 devi->pins[sc->scl_pin], devi->pins[sc->sda_pin]); 130 131 /* add generic bit-banging code */ 132 bitbang = device_add_child(dev, "iicbb", -1); 133 device_probe_and_attach(bitbang); 134 135 return (0); 136} 137 138/* 139 * Reset bus by setting SDA first and then SCL. 140 * Must always be called with gpio bus locked. 141 */ 142static void 143gpioiic_reset_bus(device_t dev) 144{ 145 struct gpioiic_softc *sc = device_get_softc(dev); 146 147 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 148 GPIO_PIN_INPUT); 149 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 150 GPIO_PIN_INPUT); 151} 152 153static int 154gpioiic_callback(device_t dev, int index, caddr_t data) 155{ 156 struct gpioiic_softc *sc = device_get_softc(dev); 157 int error, how; 158 159 how = GPIOBUS_DONTWAIT; 160 if (data != NULL && (int)*data == IIC_WAIT) 161 how = GPIOBUS_WAIT; 162 error = 0; 163 switch (index) { 164 case IIC_REQUEST_BUS: 165 error = GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev, how); 166 break; 167 case IIC_RELEASE_BUS: 168 GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev); 169 break; 170 default: 171 error = EINVAL; 172 } 173 174 return (error); 175} 176 177static void 178gpioiic_setsda(device_t dev, int val) 179{ 180 struct gpioiic_softc *sc = device_get_softc(dev); 181 182 if (val == 0) { 183 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0); 184 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 185 GPIO_PIN_OUTPUT); 186 } else { 187 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 188 GPIO_PIN_INPUT); 189 } 190} 191 192static void 193gpioiic_setscl(device_t dev, int val) 194{ 195 struct gpioiic_softc *sc = device_get_softc(dev); 196 197 if (val == 0) { 198 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0); 199 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 200 GPIO_PIN_OUTPUT); 201 } else { 202 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 203 GPIO_PIN_INPUT); 204 } 205} 206 207static int 208gpioiic_getscl(device_t dev) 209{ 210 struct gpioiic_softc *sc = device_get_softc(dev); 211 unsigned int val; 212 213 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 214 GPIO_PIN_INPUT); 215 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val); 216 217 return ((int)val); 218} 219 220static int 221gpioiic_getsda(device_t dev) 222{ 223 struct gpioiic_softc *sc = device_get_softc(dev); 224 unsigned int val; 225 226 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 227 GPIO_PIN_INPUT); 228 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val); 229 230 return ((int)val); 231} 232 233static int 234gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 235{ 236 struct gpioiic_softc *sc; 237 238 sc = device_get_softc(dev); 239 gpioiic_reset_bus(sc->sc_dev); 240 241 return (IIC_ENOADDR); 242} 243 244#ifdef FDT 245static phandle_t 246gpioiic_get_node(device_t bus, device_t dev) 247{ 248 249 /* We only have one child, the iicbb, which needs our own node. */ 250 return (ofw_bus_get_node(bus)); 251} 252#endif 253 254static devclass_t gpioiic_devclass; 255 256static device_method_t gpioiic_methods[] = { 257 /* Device interface */ 258 DEVMETHOD(device_probe, gpioiic_probe), 259 DEVMETHOD(device_attach, gpioiic_attach), 260 DEVMETHOD(device_detach, bus_generic_detach), 261 262 /* iicbb interface */ 263 DEVMETHOD(iicbb_callback, gpioiic_callback), 264 DEVMETHOD(iicbb_setsda, gpioiic_setsda), 265 DEVMETHOD(iicbb_setscl, gpioiic_setscl), 266 DEVMETHOD(iicbb_getsda, gpioiic_getsda), 267 DEVMETHOD(iicbb_getscl, gpioiic_getscl), 268 DEVMETHOD(iicbb_reset, gpioiic_reset), 269 270#ifdef FDT 271 /* OFW bus interface */ 272 DEVMETHOD(ofw_bus_get_node, gpioiic_get_node), 273#endif 274 275 { 0, 0 } 276}; 277 278static driver_t gpioiic_driver = { 279 "gpioiic", 280 gpioiic_methods, 281 sizeof(struct gpioiic_softc), 282}; 283 284DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0); 285DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0); 286MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 287MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1); 288