nslu2_iic.c revision 1.3.12.1
1 /* $NetBSD: nslu2_iic.c,v 1.3.12.1 2008/06/02 13:22:02 mjf Exp $ */ 2 3 /*- 4 * Copyright (c) 2006 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Steve C. Woodford. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/device.h> 36 #include <sys/mutex.h> 37 #include <sys/bus.h> 38 39 #include <dev/i2c/i2cvar.h> 40 #include <dev/i2c/i2c_bitbang.h> 41 42 #include <arm/xscale/ixp425reg.h> 43 #include <arm/xscale/ixp425var.h> 44 45 #include <evbarm/nslu2/nslu2reg.h> 46 47 struct slugiic_softc { 48 struct device sc_dev; 49 struct i2c_controller sc_ic; 50 struct i2c_bitbang_ops sc_ibo; 51 kmutex_t sc_lock; 52 #ifdef DIAGNOSTIC 53 uint32_t sc_dirout; 54 #endif 55 }; 56 57 static int 58 slugiic_acquire_bus(void *arg, int flags) 59 { 60 struct slugiic_softc *sc = arg; 61 62 if (flags & I2C_F_POLL) 63 return (0); 64 65 mutex_enter(&sc->sc_lock); 66 return (0); 67 } 68 69 static void 70 slugiic_release_bus(void *arg, int flags) 71 { 72 struct slugiic_softc *sc = arg; 73 74 if (flags & I2C_F_POLL) 75 return; 76 77 mutex_exit(&sc->sc_lock); 78 } 79 80 static int 81 slugiic_send_start(void *arg, int flags) 82 { 83 struct slugiic_softc *sc = arg; 84 85 return (i2c_bitbang_send_start(sc, flags, &sc->sc_ibo)); 86 } 87 88 static int 89 slugiic_send_stop(void *arg, int flags) 90 { 91 struct slugiic_softc *sc = arg; 92 93 return (i2c_bitbang_send_stop(sc, flags, &sc->sc_ibo)); 94 } 95 96 static int 97 slugiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags) 98 { 99 struct slugiic_softc *sc = arg; 100 101 return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_ibo)); 102 } 103 104 static int 105 slugiic_read_byte(void *arg, uint8_t *vp, int flags) 106 { 107 struct slugiic_softc *sc = arg; 108 109 return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_ibo)); 110 } 111 112 static int 113 slugiic_write_byte(void *arg, uint8_t v, int flags) 114 { 115 struct slugiic_softc *sc = arg; 116 117 return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_ibo)); 118 } 119 120 static void 121 slugiic_set_dir(void *arg, uint32_t bits) 122 { 123 #ifdef DIAGNOSTIC 124 struct slugiic_softc *sc = arg; 125 126 sc->sc_dirout = bits; 127 #endif 128 } 129 130 static void 131 slugiic_set_bits(void *arg, uint32_t bits) 132 { 133 uint32_t reg; 134 int s; 135 136 #ifdef DIAGNOSTIC 137 struct slugiic_softc *sc = arg; 138 if (sc->sc_dirout == 0 && (bits & GPIO_I2C_SDA_BIT) == 0) { 139 printf("slugiic_set_bits: SDA low in input mode!\n"); 140 bits |= GPIO_I2C_SDA_BIT; 141 } 142 #endif 143 144 s = splhigh(); 145 146 reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOUTR); 147 reg &= ~(GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT); 148 GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOUTR, reg | bits); 149 150 /* 151 * Enable output only if the SDA/SCL lines are to be driven low. 152 * Otherwise switch to input and allow the pullup resistors 153 * to hold them high. 154 */ 155 reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); 156 reg &= ~(GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT); 157 reg |= bits & (GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT); 158 GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, reg); 159 160 splx(s); 161 } 162 163 static uint32_t 164 slugiic_read_bits(void *arg) 165 { 166 uint32_t reg; 167 168 #ifdef DIAGNOSTIC 169 struct slugiic_softc *sc = arg; 170 if (sc->sc_dirout) 171 printf("slugiic_read_bits: Read in output mode\n"); 172 #endif 173 174 reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPINR); 175 return (reg & (GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT)); 176 } 177 178 static void 179 slugiic_deferred_attach(struct device *device) 180 { 181 struct slugiic_softc *sc = (struct slugiic_softc *)device; 182 struct i2cbus_attach_args iba; 183 uint32_t reg; 184 185 reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOUTR); 186 reg |= GPIO_I2C_SDA_BIT | GPIO_I2C_SCL_BIT; 187 GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOUTR, reg); 188 189 reg = GPIO_CONF_READ_4(ixp425_softc, IXP425_GPIO_GPOER); 190 reg &= ~GPIO_I2C_SCL_BIT; 191 reg |= GPIO_I2C_SDA_BIT; 192 GPIO_CONF_WRITE_4(ixp425_softc, IXP425_GPIO_GPOER, reg); 193 194 iba.iba_tag = &sc->sc_ic; 195 (void) config_found_ia(&sc->sc_dev, "i2cbus", &iba, iicbus_print); 196 } 197 198 static int 199 slugiic_match(struct device *parent, struct cfdata *cf, void *arg) 200 { 201 202 return (1); 203 } 204 205 static void 206 slugiic_attach(struct device *parent, struct device *self, void *arg) 207 { 208 struct slugiic_softc *sc = (struct slugiic_softc *)self; 209 210 aprint_naive("\n"); 211 aprint_normal(": I2C bus\n"); 212 213 sc->sc_ic.ic_cookie = sc; 214 sc->sc_ic.ic_acquire_bus = slugiic_acquire_bus; 215 sc->sc_ic.ic_release_bus = slugiic_release_bus; 216 sc->sc_ic.ic_exec = NULL; 217 sc->sc_ic.ic_send_start = slugiic_send_start; 218 sc->sc_ic.ic_send_stop = slugiic_send_stop; 219 sc->sc_ic.ic_initiate_xfer = slugiic_initiate_xfer; 220 sc->sc_ic.ic_read_byte = slugiic_read_byte; 221 sc->sc_ic.ic_write_byte = slugiic_write_byte; 222 223 sc->sc_ibo.ibo_set_dir = slugiic_set_dir; 224 sc->sc_ibo.ibo_set_bits = slugiic_set_bits; 225 sc->sc_ibo.ibo_read_bits = slugiic_read_bits; 226 sc->sc_ibo.ibo_bits[I2C_BIT_SDA] = GPIO_I2C_SDA_BIT; 227 sc->sc_ibo.ibo_bits[I2C_BIT_SCL] = GPIO_I2C_SCL_BIT; 228 sc->sc_ibo.ibo_bits[I2C_BIT_OUTPUT] = 1; 229 sc->sc_ibo.ibo_bits[I2C_BIT_INPUT] = 0; 230 231 mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE); 232 233 #ifdef DIAGNOSTIC 234 sc->sc_dirout = 0; 235 #endif 236 237 /* 238 * Defer until ixp425_softc has been initialised 239 */ 240 config_interrupts(self, slugiic_deferred_attach); 241 } 242 243 CFATTACH_DECL(slugiic, sizeof(struct slugiic_softc), 244 slugiic_match, slugiic_attach, NULL, NULL); 245
Indexes created Sun Oct 19 02:09:48 GMT 2025