1 /*- 2 * Copyright (c) 2011, Aleksandr Rybalko <ray@dlink.ua> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * 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_gpio.h" 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 36 #include <sys/bus.h> 37 #include <sys/kernel.h> 38 #include <sys/module.h> 39 #include <sys/rman.h> 40 #include <sys/sysctl.h> 41 42 #include <sys/gpio.h> 43 #include "gpiobus_if.h" 44 45 #include <dev/gpio/gpiobusvar.h> 46 47 #include <dev/spibus/spi.h> 48 #include <dev/spibus/spibusvar.h> 49 #include "spibus_if.h" 50 51 #ifdef GPIO_SPI_DEBUG 52 #define dprintf printf 53 #else 54 #define dprintf(x, arg...) 55 #endif /* GPIO_SPI_DEBUG */ 56 57 struct gpio_spi_softc { 58 device_t sc_dev; 59 device_t sc_busdev; 60 int sc_freq; 61 uint8_t sc_sclk; 62 uint8_t sc_miso; 63 uint8_t sc_mosi; 64 uint8_t sc_cs0; 65 uint8_t sc_cs1; 66 uint8_t sc_cs2; 67 uint8_t sc_cs3; 68 }; 69 70 static void gpio_spi_chip_activate(struct gpio_spi_softc *, int); 71 static void gpio_spi_chip_deactivate(struct gpio_spi_softc *, int); 72 73 static int 74 gpio_spi_probe(device_t dev) 75 { 76 device_set_desc(dev, "GPIO SPI bit-banging driver"); 77 return (0); 78 } 79 80 static void 81 gpio_delay(struct gpio_spi_softc *sc) 82 { 83 int d; 84 85 d = sc->sc_freq / 1000000; 86 if (d == 0) 87 d = 1; 88 89 DELAY(d); 90 } 91 92 static int 93 gpio_spi_attach(device_t dev) 94 { 95 uint32_t value; 96 struct gpio_spi_softc *sc; 97 98 sc = device_get_softc(dev); 99 sc->sc_dev = dev; 100 sc->sc_busdev = device_get_parent(dev); 101 102 /* Required variables */ 103 if (resource_int_value(device_get_name(dev), 104 device_get_unit(dev), "sclk", &value)) 105 return (ENXIO); 106 sc->sc_sclk = value & 0xff; 107 108 if (resource_int_value(device_get_name(dev), 109 device_get_unit(dev), "mosi", &value)) 110 return (ENXIO); 111 sc->sc_mosi = value & 0xff; 112 113 /* Handle no miso; we just never read back from the device */ 114 if (resource_int_value(device_get_name(dev), 115 device_get_unit(dev), "miso", &value)) 116 value = 0xff; 117 sc->sc_miso = value & 0xff; 118 119 if (resource_int_value(device_get_name(dev), 120 device_get_unit(dev), "cs0", &value)) 121 return (ENXIO); 122 sc->sc_cs0 = value & 0xff; 123 124 /* Optional variables */ 125 if (resource_int_value(device_get_name(dev), 126 device_get_unit(dev), "cs1", &value)) 127 value = 0xff; 128 sc->sc_cs1 = value & 0xff; 129 130 if (resource_int_value(device_get_name(dev), 131 device_get_unit(dev), "cs2", &value)) 132 value = 0xff; 133 sc->sc_cs2 = value & 0xff; 134 135 if (resource_int_value(device_get_name(dev), 136 device_get_unit(dev), "cs3", &value)) 137 value = 0xff; 138 sc->sc_cs3 = value & 0xff; 139 140 /* Default to 100KHz */ 141 if (resource_int_value(device_get_name(dev), 142 device_get_unit(dev), "freq", &value)) { 143 value = 100000; 144 } 145 sc->sc_freq = value; 146 147 if (bootverbose) { 148 device_printf(dev, "frequency: %d Hz\n", 149 sc->sc_freq); 150 device_printf(dev, 151 "Use GPIO pins: sclk=%d, mosi=%d, miso=%d, " 152 "cs0=%d, cs1=%d, cs2=%d, cs3=%d\n", 153 sc->sc_sclk, sc->sc_mosi, sc->sc_miso, 154 sc->sc_cs0, sc->sc_cs1, sc->sc_cs2, sc->sc_cs3); 155 } 156 157 /* Set directions */ 158 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_sclk, 159 GPIO_PIN_OUTPUT|GPIO_PIN_PULLDOWN); 160 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_mosi, 161 GPIO_PIN_OUTPUT|GPIO_PIN_PULLDOWN); 162 if (sc->sc_miso != 0xff) { 163 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_miso, 164 GPIO_PIN_INPUT|GPIO_PIN_PULLDOWN); 165 } 166 167 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_cs0, 168 GPIO_PIN_OUTPUT|GPIO_PIN_PULLUP); 169 170 if (sc->sc_cs1 != 0xff) 171 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_cs1, 172 GPIO_PIN_OUTPUT|GPIO_PIN_PULLUP); 173 if (sc->sc_cs2 != 0xff) 174 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_cs2, 175 GPIO_PIN_OUTPUT|GPIO_PIN_PULLUP); 176 if (sc->sc_cs3 != 0xff) 177 GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sc_cs3, 178 GPIO_PIN_OUTPUT|GPIO_PIN_PULLUP); 179 180 gpio_spi_chip_deactivate(sc, -1); 181 182 device_add_child(dev, "spibus", -1); 183 return (bus_generic_attach(dev)); 184 } 185 186 static int 187 gpio_spi_detach(device_t dev) 188 { 189 190 return (0); 191 } 192 193 static void 194 gpio_spi_chip_activate(struct gpio_spi_softc *sc, int cs) 195 { 196 197 /* called with locked gpiobus */ 198 switch (cs) { 199 case 0: 200 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 201 sc->sc_cs0, 0); 202 break; 203 case 1: 204 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 205 sc->sc_cs1, 0); 206 break; 207 case 2: 208 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 209 sc->sc_cs2, 0); 210 break; 211 case 3: 212 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 213 sc->sc_cs3, 0); 214 break; 215 default: 216 device_printf(sc->sc_dev, "don't have CS%d\n", cs); 217 } 218 219 gpio_delay(sc); 220 } 221 222 static void 223 gpio_spi_chip_deactivate(struct gpio_spi_softc *sc, int cs) 224 { 225 226 /* called wth locked gpiobus */ 227 /* 228 * Put CSx to high 229 */ 230 switch (cs) { 231 case -1: 232 /* All CS */ 233 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 234 sc->sc_cs0, 1); 235 if (sc->sc_cs1 == 0xff) break; 236 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 237 sc->sc_cs1, 1); 238 if (sc->sc_cs2 == 0xff) break; 239 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 240 sc->sc_cs2, 1); 241 if (sc->sc_cs3 == 0xff) break; 242 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 243 sc->sc_cs3, 1); 244 break; 245 case 0: 246 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 247 sc->sc_cs0, 1); 248 break; 249 case 1: 250 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 251 sc->sc_cs1, 1); 252 break; 253 case 2: 254 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 255 sc->sc_cs2, 1); 256 break; 257 case 3: 258 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 259 sc->sc_cs3, 1); 260 break; 261 default: 262 device_printf(sc->sc_dev, "don't have CS%d\n", cs); 263 } 264 } 265 266 static uint8_t 267 gpio_spi_txrx(struct gpio_spi_softc *sc, int cs, int mode, uint8_t data) 268 { 269 uint32_t mask, out = 0; 270 unsigned int bit; 271 272 273 /* called with locked gpiobus */ 274 275 for (mask = 0x80; mask > 0; mask >>= 1) { 276 if ((mode == SPIBUS_MODE_CPOL) || 277 (mode == SPIBUS_MODE_CPHA)) { 278 /* If mode 1 or 2 */ 279 280 /* first step */ 281 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 282 sc->sc_mosi, (data & mask)?1:0); 283 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 284 sc->sc_sclk, 0); 285 gpio_delay(sc); 286 /* second step */ 287 if (sc->sc_miso != 0xff) { 288 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, 289 sc->sc_miso, &bit); 290 out |= bit?mask:0; 291 } 292 /* Data captured */ 293 gpio_delay(sc); 294 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 295 sc->sc_sclk, 1); 296 gpio_delay(sc); 297 } else { 298 /* If mode 0 or 3 */ 299 300 /* first step */ 301 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 302 sc->sc_mosi, (data & mask)?1:0); 303 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 304 sc->sc_sclk, 1); 305 gpio_delay(sc); 306 /* second step */ 307 if (sc->sc_miso != 0xff) { 308 GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, 309 sc->sc_miso, &bit); 310 out |= bit?mask:0; 311 } 312 /* Data captured */ 313 gpio_delay(sc); 314 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 315 sc->sc_sclk, 0); 316 gpio_delay(sc); 317 } 318 } 319 320 return (out & 0xff); 321 } 322 323 static int 324 gpio_spi_transfer(device_t dev, device_t child, struct spi_command *cmd) 325 { 326 struct gpio_spi_softc *sc; 327 uint8_t *buf_in, *buf_out; 328 struct spibus_ivar *devi = SPIBUS_IVAR(child); 329 int i; 330 331 sc = device_get_softc(dev); 332 333 KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz, 334 ("TX/RX command sizes should be equal")); 335 KASSERT(cmd->tx_data_sz == cmd->rx_data_sz, 336 ("TX/RX data sizes should be equal")); 337 338 gpio_spi_chip_activate(sc, devi->cs); 339 340 /* Preset pins */ 341 if ((devi->mode == SPIBUS_MODE_CPOL) || 342 (devi->mode == SPIBUS_MODE_CPHA)) { 343 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 344 sc->sc_sclk, 1); 345 } else { 346 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 347 sc->sc_sclk, 0); 348 } 349 350 /* 351 * Transfer command 352 */ 353 buf_out = (uint8_t *)cmd->tx_cmd; 354 buf_in = (uint8_t *)cmd->rx_cmd; 355 356 for (i = 0; i < cmd->tx_cmd_sz; i++) 357 buf_in[i] = gpio_spi_txrx(sc, devi->cs, devi->mode, buf_out[i]); 358 359 /* 360 * Receive/transmit data (depends on command) 361 */ 362 buf_out = (uint8_t *)cmd->tx_data; 363 buf_in = (uint8_t *)cmd->rx_data; 364 for (i = 0; i < cmd->tx_data_sz; i++) 365 buf_in[i] = gpio_spi_txrx(sc, devi->cs, devi->mode, buf_out[i]); 366 367 /* Return pins to mode default */ 368 if ((devi->mode == SPIBUS_MODE_CPOL) || 369 (devi->mode == SPIBUS_MODE_CPHA)) { 370 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 371 sc->sc_sclk, 1); 372 } else { 373 GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, 374 sc->sc_sclk, 0); 375 } 376 377 gpio_spi_chip_deactivate(sc, devi->cs); 378 379 return (0); 380 } 381 382 static device_method_t gpio_spi_methods[] = { 383 /* Device interface */ 384 DEVMETHOD(device_probe, gpio_spi_probe), 385 DEVMETHOD(device_attach, gpio_spi_attach), 386 DEVMETHOD(device_detach, gpio_spi_detach), 387 388 DEVMETHOD(spibus_transfer, gpio_spi_transfer), 389 390 {0, 0} 391 }; 392 393 static driver_t gpio_spi_driver = { 394 "gpiospi", 395 gpio_spi_methods, 396 sizeof(struct gpio_spi_softc), 397 }; 398 399 DRIVER_MODULE(gpiospi, gpiobus, gpio_spi_driver, 0, 0); 400 DRIVER_MODULE(spibus, gpiospi, spibus_driver, 0, 0); 401 MODULE_DEPEND(spi, gpiospi, 1, 1, 1); 402 MODULE_DEPEND(gpiobus, gpiospi, 1, 1, 1); 403