pxa2x0_i2c.c revision 1.1
1 /* $NetBSD: pxa2x0_i2c.c,v 1.1 2006/12/17 16:03:33 peter Exp $ */ 2 /* $OpenBSD: pxa2x0_i2c.c,v 1.2 2005/05/26 03:52:07 pascoe Exp $ */ 3 4 /* 5 * Copyright (c) 2005 Christopher Pascoe <pascoe (at) openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include <sys/cdefs.h> 21 __KERNEL_RCSID(0, "$NetBSD: pxa2x0_i2c.c,v 1.1 2006/12/17 16:03:33 peter Exp $"); 22 23 #include <sys/param.h> 24 #include <sys/systm.h> 25 #include <sys/device.h> 26 27 #include <machine/bus.h> 28 29 #include <arm/xscale/pxa2x0reg.h> 30 #include <arm/xscale/pxa2x0var.h> 31 #include <arm/xscale/pxa2x0_i2c.h> 32 #include <arm/xscale/pxa2x0_gpio.h> 33 34 #define I2C_RETRY_COUNT 10 35 36 int 37 pxa2x0_i2c_attach_sub(struct pxa2x0_i2c_softc *sc) 38 { 39 40 if (bus_space_map(sc->sc_iot, PXA2X0_I2C_BASE, 41 PXA2X0_I2C_SIZE, 0, &sc->sc_ioh)) { 42 sc->sc_size = 0; 43 return EIO; 44 } 45 bus_space_barrier(sc->sc_iot, sc->sc_ioh, 0, sc->sc_size, 46 BUS_SPACE_BARRIER_READ|BUS_SPACE_BARRIER_WRITE); 47 48 /* 49 * Configure the alternate functions. The _IN is arbitrary, as the 50 * direction is managed by the I2C unit when comms are in progress. 51 */ 52 pxa2x0_gpio_set_function(117, GPIO_ALT_FN_1_IN); /* SCL */ 53 pxa2x0_gpio_set_function(118, GPIO_ALT_FN_1_IN); /* SDA */ 54 55 pxa2x0_i2c_init(sc); 56 57 return 0; 58 } 59 60 int 61 pxa2x0_i2c_detach_sub(struct pxa2x0_i2c_softc *sc) 62 { 63 64 if (sc->sc_size) { 65 bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_size); 66 sc->sc_size = 0; 67 } 68 pxa2x0_clkman_config(CKEN_I2C, 0); 69 70 return 0; 71 } 72 73 void 74 pxa2x0_i2c_init(struct pxa2x0_i2c_softc *sc) 75 { 76 77 pxa2x0_i2c_open(sc); 78 pxa2x0_i2c_close(sc); 79 } 80 81 void 82 pxa2x0_i2c_open(struct pxa2x0_i2c_softc *sc) 83 { 84 85 /* Enable the clock to the standard I2C unit. */ 86 pxa2x0_clkman_config(CKEN_I2C, 1); 87 } 88 89 void 90 pxa2x0_i2c_close(struct pxa2x0_i2c_softc *sc) 91 { 92 93 /* Reset and disable the standard I2C unit. */ 94 bus_space_write_4(sc->sc_iot, sc->sc_ioh, I2C_ICR, ICR_UR); 95 bus_space_write_4(sc->sc_iot, sc->sc_ioh, I2C_ISAR, 0); 96 delay(1); 97 pxa2x0_clkman_config(CKEN_I2C, 0); 98 } 99 100 int 101 pxa2x0_i2c_read(struct pxa2x0_i2c_softc *sc, u_char slave, u_char *valuep) 102 { 103 bus_space_tag_t iot = sc->sc_iot; 104 bus_space_handle_t ioh = sc->sc_ioh; 105 int timeout; 106 int tries = I2C_RETRY_COUNT; 107 uint32_t rv; 108 109 retry: 110 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 111 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 112 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE | ISR_IRF); 113 delay(1); 114 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 115 116 /* Write slave device address. */ 117 bus_space_write_4(iot, ioh, I2C_IDBR, (slave<<1) | 0x1); 118 rv = bus_space_read_4(iot, ioh, I2C_ICR); 119 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_START); 120 rv = bus_space_read_4(iot, ioh, I2C_ICR); 121 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 122 rv = bus_space_read_4(iot, ioh, I2C_ICR); 123 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 124 125 timeout = 10000; 126 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 127 if (timeout-- == 0) 128 goto err; 129 delay(1); 130 } 131 132 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 133 134 rv = bus_space_read_4(iot, ioh, I2C_ICR); 135 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_START); 136 137 /* Read data value. */ 138 rv = bus_space_read_4(iot, ioh, I2C_ICR); 139 bus_space_write_4(iot, ioh, I2C_ICR, rv | 140 (ICR_STOP | ICR_ACKNAK)); 141 rv = bus_space_read_4(iot, ioh, I2C_ICR); 142 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 143 144 timeout = 10000; 145 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_IRF) == 0) { 146 if (timeout-- == 0) 147 goto err; 148 delay(1); 149 } 150 151 bus_space_write_4(iot, ioh, I2C_ISR, ISR_IRF); 152 153 rv = bus_space_read_4(iot, ioh, I2C_IDBR); 154 *valuep = (u_char)rv; 155 rv = bus_space_read_4(iot, ioh, I2C_ICR); 156 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~(ICR_STOP | ICR_ACKNAK)); 157 158 return 0; 159 160 err: 161 if (tries-- >= 0) 162 goto retry; 163 164 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 165 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 166 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE | ISR_IRF); 167 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 168 169 return EIO; 170 } 171 172 int 173 pxa2x0_i2c_write(struct pxa2x0_i2c_softc *sc, u_char slave, u_char value) 174 { 175 bus_space_tag_t iot = sc->sc_iot; 176 bus_space_handle_t ioh = sc->sc_ioh; 177 int timeout; 178 int tries = I2C_RETRY_COUNT; 179 uint32_t rv; 180 181 retry: 182 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 183 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 184 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 185 delay(1); 186 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 187 188 /* Write slave device address. */ 189 bus_space_write_4(iot, ioh, I2C_IDBR, (slave<<1)); 190 rv = bus_space_read_4(iot, ioh, I2C_ICR); 191 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_START); 192 rv = bus_space_read_4(iot, ioh, I2C_ICR); 193 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 194 rv = bus_space_read_4(iot, ioh, I2C_ICR); 195 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 196 197 timeout = 10000; 198 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 199 if (timeout-- == 0) 200 goto err; 201 delay(1); 202 } 203 if ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ACKNAK) != 0) 204 goto err; 205 206 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 207 208 /* Write data. */ 209 rv = bus_space_read_4(iot, ioh, I2C_ICR); 210 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_START); 211 rv = bus_space_read_4(iot, ioh, I2C_ICR); 212 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_STOP); 213 bus_space_write_4(iot, ioh, I2C_IDBR, value); 214 rv = bus_space_read_4(iot, ioh, I2C_ICR); 215 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 216 217 timeout = 10000; 218 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 219 if (timeout-- == 0) 220 goto err; 221 delay(1); 222 } 223 if ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ACKNAK) != 0) 224 goto err; 225 226 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 227 228 rv = bus_space_read_4(iot, ioh, I2C_ICR); 229 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 230 231 return 0; 232 233 err: 234 if (tries-- >= 0) 235 goto retry; 236 237 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 238 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 239 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 240 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 241 242 return EIO; 243 } 244 245 int 246 pxa2x0_i2c_write_2(struct pxa2x0_i2c_softc *sc, u_char slave, u_short value) 247 { 248 bus_space_tag_t iot = sc->sc_iot; 249 bus_space_handle_t ioh = sc->sc_ioh; 250 int timeout; 251 int tries = I2C_RETRY_COUNT; 252 uint32_t rv; 253 254 retry: 255 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 256 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 257 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 258 delay(1); 259 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 260 261 /* Write slave device address. */ 262 bus_space_write_4(iot, ioh, I2C_IDBR, (slave<<1)); 263 rv = bus_space_read_4(iot, ioh, I2C_ICR); 264 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_START); 265 rv = bus_space_read_4(iot, ioh, I2C_ICR); 266 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 267 rv = bus_space_read_4(iot, ioh, I2C_ICR); 268 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 269 270 timeout = 10000; 271 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 272 if (timeout-- == 0) 273 goto err; 274 delay(1); 275 } 276 if ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ACKNAK) != 0) 277 goto err; 278 279 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 280 281 /* Write upper 8 bits of data. */ 282 bus_space_write_4(iot, ioh, I2C_IDBR, (value >> 8) & 0xff); 283 rv = bus_space_read_4(iot, ioh, I2C_ICR); 284 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_START); 285 rv = bus_space_read_4(iot, ioh, I2C_ICR); 286 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 287 rv = bus_space_read_4(iot, ioh, I2C_ICR); 288 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 289 290 timeout = 10000; 291 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 292 if (timeout-- == 0) 293 goto err; 294 delay(1); 295 } 296 if ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ACKNAK) != 0) 297 goto err; 298 299 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 300 301 /* Write lower 8 bits of data. */ 302 bus_space_write_4(iot, ioh, I2C_IDBR, value & 0xff); 303 rv = bus_space_read_4(iot, ioh, I2C_ICR); 304 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_START); 305 rv = bus_space_read_4(iot, ioh, I2C_ICR); 306 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_STOP); 307 rv = bus_space_read_4(iot, ioh, I2C_ICR); 308 bus_space_write_4(iot, ioh, I2C_ICR, rv | ICR_TB); 309 310 timeout = 10000; 311 while ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ITE) == 0) { 312 if (timeout-- == 0) 313 goto err; 314 delay(1); 315 } 316 if ((bus_space_read_4(iot, ioh, I2C_ISR) & ISR_ACKNAK) != 0) 317 goto err; 318 319 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 320 321 rv = bus_space_read_4(iot, ioh, I2C_ICR); 322 bus_space_write_4(iot, ioh, I2C_ICR, rv & ~ICR_STOP); 323 324 return 0; 325 326 err: 327 if (tries-- >= 0) 328 goto retry; 329 330 bus_space_write_4(iot, ioh, I2C_ICR, ICR_UR); 331 bus_space_write_4(iot, ioh, I2C_ISAR, 0x00); 332 bus_space_write_4(iot, ioh, I2C_ISR, ISR_ITE); 333 bus_space_write_4(iot, ioh, I2C_ICR, ICR_IUE | ICR_SCLE); 334 335 return EIO; 336 } 337
Indexes created Mon Sep 29 13:09:55 GMT 2025