1 /* 2 * Copyright (c) 2014 Google, Inc 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <fdtdec.h> 11 #include <malloc.h> 12 #include <spi.h> 13 #include <dm/device-internal.h> 14 #include <dm/uclass-internal.h> 15 #include <dm/root.h> 16 #include <dm/lists.h> 17 #include <dm/util.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 static int spi_set_speed_mode(struct udevice *bus, int speed, int mode) 22 { 23 struct dm_spi_ops *ops; 24 int ret; 25 26 ops = spi_get_ops(bus); 27 if (ops->set_speed) 28 ret = ops->set_speed(bus, speed); 29 else 30 ret = -EINVAL; 31 if (ret) { 32 printf("Cannot set speed (err=%d)\n", ret); 33 return ret; 34 } 35 36 if (ops->set_mode) 37 ret = ops->set_mode(bus, mode); 38 else 39 ret = -EINVAL; 40 if (ret) { 41 printf("Cannot set mode (err=%d)\n", ret); 42 return ret; 43 } 44 45 return 0; 46 } 47 48 int spi_claim_bus(struct spi_slave *slave) 49 { 50 struct udevice *dev = slave->dev; 51 struct udevice *bus = dev->parent; 52 struct dm_spi_ops *ops = spi_get_ops(bus); 53 struct dm_spi_bus *spi = bus->uclass_priv; 54 int speed; 55 int ret; 56 57 speed = slave->max_hz; 58 if (spi->max_hz) { 59 if (speed) 60 speed = min(speed, spi->max_hz); 61 else 62 speed = spi->max_hz; 63 } 64 if (!speed) 65 speed = 100000; 66 ret = spi_set_speed_mode(bus, speed, slave->mode); 67 if (ret) 68 return ret; 69 70 return ops->claim_bus ? ops->claim_bus(bus) : 0; 71 } 72 73 void spi_release_bus(struct spi_slave *slave) 74 { 75 struct udevice *dev = slave->dev; 76 struct udevice *bus = dev->parent; 77 struct dm_spi_ops *ops = spi_get_ops(bus); 78 79 if (ops->release_bus) 80 ops->release_bus(bus); 81 } 82 83 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, 84 const void *dout, void *din, unsigned long flags) 85 { 86 struct udevice *dev = slave->dev; 87 struct udevice *bus = dev->parent; 88 89 if (bus->uclass->uc_drv->id != UCLASS_SPI) 90 return -EOPNOTSUPP; 91 92 return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags); 93 } 94 95 int spi_post_bind(struct udevice *dev) 96 { 97 /* Scan the bus for devices */ 98 return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false); 99 } 100 101 int spi_post_probe(struct udevice *dev) 102 { 103 struct dm_spi_bus *spi = dev->uclass_priv; 104 105 spi->max_hz = fdtdec_get_int(gd->fdt_blob, dev->of_offset, 106 "spi-max-frequency", 0); 107 108 return 0; 109 } 110 111 int spi_chip_select(struct udevice *dev) 112 { 113 struct spi_slave *slave = dev_get_parentdata(dev); 114 115 return slave ? slave->cs : -ENOENT; 116 } 117 118 /** 119 * spi_find_chip_select() - Find the slave attached to chip select 120 * 121 * @bus: SPI bus to search 122 * @cs: Chip select to look for 123 * @devp: Returns the slave device if found 124 * @return 0 if found, -ENODEV on error 125 */ 126 static int spi_find_chip_select(struct udevice *bus, int cs, 127 struct udevice **devp) 128 { 129 struct udevice *dev; 130 131 for (device_find_first_child(bus, &dev); dev; 132 device_find_next_child(&dev)) { 133 struct spi_slave store; 134 struct spi_slave *slave = dev_get_parentdata(dev); 135 136 if (!slave) { 137 slave = &store; 138 spi_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, 139 slave); 140 } 141 debug("%s: slave=%p, cs=%d\n", __func__, slave, 142 slave ? slave->cs : -1); 143 if (slave && slave->cs == cs) { 144 *devp = dev; 145 return 0; 146 } 147 } 148 149 return -ENODEV; 150 } 151 152 int spi_cs_is_valid(unsigned int busnum, unsigned int cs) 153 { 154 struct spi_cs_info info; 155 struct udevice *bus; 156 int ret; 157 158 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 159 if (ret) { 160 debug("%s: No bus %d\n", __func__, busnum); 161 return ret; 162 } 163 164 return spi_cs_info(bus, cs, &info); 165 } 166 167 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info) 168 { 169 struct spi_cs_info local_info; 170 struct dm_spi_ops *ops; 171 int ret; 172 173 if (!info) 174 info = &local_info; 175 176 /* If there is a device attached, return it */ 177 info->dev = NULL; 178 ret = spi_find_chip_select(bus, cs, &info->dev); 179 if (!ret) 180 return 0; 181 182 /* 183 * Otherwise ask the driver. For the moment we don't have CS info. 184 * When we do we could provide the driver with a helper function 185 * to figure out what chip selects are valid, or just handle the 186 * request. 187 */ 188 ops = spi_get_ops(bus); 189 if (ops->cs_info) 190 return ops->cs_info(bus, cs, info); 191 192 /* 193 * We could assume there is at least one valid chip select, but best 194 * to be sure and return an error in this case. The driver didn't 195 * care enough to tell us. 196 */ 197 return -ENODEV; 198 } 199 200 int spi_bind_device(struct udevice *bus, int cs, const char *drv_name, 201 const char *dev_name, struct udevice **devp) 202 { 203 struct driver *drv; 204 int ret; 205 206 drv = lists_driver_lookup_name(drv_name); 207 if (!drv) { 208 printf("Cannot find driver '%s'\n", drv_name); 209 return -ENOENT; 210 } 211 ret = device_bind(bus, drv, dev_name, NULL, -1, devp); 212 if (ret) { 213 printf("Cannot create device named '%s' (err=%d)\n", 214 dev_name, ret); 215 return ret; 216 } 217 218 return 0; 219 } 220 221 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 222 struct udevice **devp) 223 { 224 struct udevice *bus, *dev; 225 int ret; 226 227 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 228 if (ret) { 229 debug("%s: No bus %d\n", __func__, busnum); 230 return ret; 231 } 232 ret = spi_find_chip_select(bus, cs, &dev); 233 if (ret) { 234 debug("%s: No cs %d\n", __func__, cs); 235 return ret; 236 } 237 *busp = bus; 238 *devp = dev; 239 240 return ret; 241 } 242 243 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 244 const char *drv_name, const char *dev_name, 245 struct udevice **busp, struct spi_slave **devp) 246 { 247 struct udevice *bus, *dev; 248 struct spi_slave *slave; 249 bool created = false; 250 int ret; 251 252 ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus); 253 if (ret) { 254 printf("Invalid bus %d (err=%d)\n", busnum, ret); 255 return ret; 256 } 257 ret = spi_find_chip_select(bus, cs, &dev); 258 259 /* 260 * If there is no such device, create one automatically. This means 261 * that we don't need a device tree node or platform data for the 262 * SPI flash chip - we will bind to the correct driver. 263 */ 264 if (ret == -ENODEV && drv_name) { 265 debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n", 266 __func__, dev_name, busnum, cs, drv_name); 267 ret = spi_bind_device(bus, cs, drv_name, dev_name, &dev); 268 if (ret) 269 return ret; 270 created = true; 271 } else if (ret) { 272 printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs, 273 ret); 274 return ret; 275 } 276 277 if (!device_active(dev)) { 278 slave = (struct spi_slave *)calloc(1, 279 sizeof(struct spi_slave)); 280 if (!slave) { 281 ret = -ENOMEM; 282 goto err; 283 } 284 285 ret = spi_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, 286 slave); 287 if (ret) 288 goto err; 289 slave->cs = cs; 290 slave->dev = dev; 291 ret = device_probe_child(dev, slave); 292 free(slave); 293 if (ret) 294 goto err; 295 } 296 297 ret = spi_set_speed_mode(bus, speed, mode); 298 if (ret) 299 goto err; 300 301 *busp = bus; 302 *devp = dev_get_parentdata(dev); 303 debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp); 304 305 return 0; 306 307 err: 308 if (created) { 309 device_remove(dev); 310 device_unbind(dev); 311 } 312 313 return ret; 314 } 315 316 /* Compatibility function - to be removed */ 317 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node, 318 int bus_node) 319 { 320 struct udevice *bus, *dev; 321 int ret; 322 323 ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus); 324 if (ret) 325 return NULL; 326 ret = device_get_child_by_of_offset(bus, node, &dev); 327 if (ret) 328 return NULL; 329 return dev_get_parentdata(dev); 330 } 331 332 /* Compatibility function - to be removed */ 333 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs, 334 unsigned int speed, unsigned int mode) 335 { 336 struct spi_slave *slave; 337 struct udevice *dev; 338 int ret; 339 340 ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev, 341 &slave); 342 if (ret) 343 return NULL; 344 345 return slave; 346 } 347 348 void spi_free_slave(struct spi_slave *slave) 349 { 350 device_remove(slave->dev); 351 slave->dev = NULL; 352 } 353 354 int spi_ofdata_to_platdata(const void *blob, int node, 355 struct spi_slave *spi) 356 { 357 int mode = 0; 358 359 spi->cs = fdtdec_get_int(blob, node, "reg", -1); 360 spi->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0); 361 if (fdtdec_get_bool(blob, node, "spi-cpol")) 362 mode |= SPI_CPOL; 363 if (fdtdec_get_bool(blob, node, "spi-cpha")) 364 mode |= SPI_CPHA; 365 if (fdtdec_get_bool(blob, node, "spi-cs-high")) 366 mode |= SPI_CS_HIGH; 367 if (fdtdec_get_bool(blob, node, "spi-half-duplex")) 368 mode |= SPI_PREAMBLE; 369 spi->mode = mode; 370 371 return 0; 372 } 373 374 UCLASS_DRIVER(spi) = { 375 .id = UCLASS_SPI, 376 .name = "spi", 377 .post_bind = spi_post_bind, 378 .post_probe = spi_post_probe, 379 .per_device_auto_alloc_size = sizeof(struct dm_spi_bus), 380 }; 381 382 UCLASS_DRIVER(spi_generic) = { 383 .id = UCLASS_SPI_GENERIC, 384 .name = "spi_generic", 385 }; 386 387 U_BOOT_DRIVER(spi_generic_drv) = { 388 .name = "spi_generic_drv", 389 .id = UCLASS_SPI_GENERIC, 390 }; 391