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, (int)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_child_post_bind(struct udevice *dev) 102 { 103 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 104 105 if (dev->of_offset == -1) 106 return 0; 107 108 return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat); 109 } 110 111 int spi_post_probe(struct udevice *bus) 112 { 113 struct dm_spi_bus *spi = bus->uclass_priv; 114 115 spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset, 116 "spi-max-frequency", 0); 117 118 return 0; 119 } 120 121 int spi_child_pre_probe(struct udevice *dev) 122 { 123 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 124 struct spi_slave *slave = dev_get_parentdata(dev); 125 126 /* 127 * This is needed because we pass struct spi_slave around the place 128 * instead slave->dev (a struct udevice). So we have to have some 129 * way to access the slave udevice given struct spi_slave. Once we 130 * change the SPI API to use udevice instead of spi_slave, we can 131 * drop this. 132 */ 133 slave->dev = dev; 134 135 slave->max_hz = plat->max_hz; 136 slave->mode = plat->mode; 137 138 return 0; 139 } 140 141 int spi_chip_select(struct udevice *dev) 142 { 143 struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev); 144 145 return plat ? plat->cs : -ENOENT; 146 } 147 148 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp) 149 { 150 struct udevice *dev; 151 152 for (device_find_first_child(bus, &dev); dev; 153 device_find_next_child(&dev)) { 154 struct dm_spi_slave_platdata *plat; 155 156 plat = dev_get_parent_platdata(dev); 157 debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs); 158 if (plat->cs == cs) { 159 *devp = dev; 160 return 0; 161 } 162 } 163 164 return -ENODEV; 165 } 166 167 int spi_cs_is_valid(unsigned int busnum, unsigned int cs) 168 { 169 struct spi_cs_info info; 170 struct udevice *bus; 171 int ret; 172 173 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 174 if (ret) { 175 debug("%s: No bus %d\n", __func__, busnum); 176 return ret; 177 } 178 179 return spi_cs_info(bus, cs, &info); 180 } 181 182 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info) 183 { 184 struct spi_cs_info local_info; 185 struct dm_spi_ops *ops; 186 int ret; 187 188 if (!info) 189 info = &local_info; 190 191 /* If there is a device attached, return it */ 192 info->dev = NULL; 193 ret = spi_find_chip_select(bus, cs, &info->dev); 194 if (!ret) 195 return 0; 196 197 /* 198 * Otherwise ask the driver. For the moment we don't have CS info. 199 * When we do we could provide the driver with a helper function 200 * to figure out what chip selects are valid, or just handle the 201 * request. 202 */ 203 ops = spi_get_ops(bus); 204 if (ops->cs_info) 205 return ops->cs_info(bus, cs, info); 206 207 /* 208 * We could assume there is at least one valid chip select, but best 209 * to be sure and return an error in this case. The driver didn't 210 * care enough to tell us. 211 */ 212 return -ENODEV; 213 } 214 215 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 216 struct udevice **devp) 217 { 218 struct udevice *bus, *dev; 219 int ret; 220 221 ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus); 222 if (ret) { 223 debug("%s: No bus %d\n", __func__, busnum); 224 return ret; 225 } 226 ret = spi_find_chip_select(bus, cs, &dev); 227 if (ret) { 228 debug("%s: No cs %d\n", __func__, cs); 229 return ret; 230 } 231 *busp = bus; 232 *devp = dev; 233 234 return ret; 235 } 236 237 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 238 const char *drv_name, const char *dev_name, 239 struct udevice **busp, struct spi_slave **devp) 240 { 241 struct udevice *bus, *dev; 242 bool created = false; 243 int ret; 244 245 ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus); 246 if (ret) { 247 printf("Invalid bus %d (err=%d)\n", busnum, ret); 248 return ret; 249 } 250 ret = spi_find_chip_select(bus, cs, &dev); 251 252 /* 253 * If there is no such device, create one automatically. This means 254 * that we don't need a device tree node or platform data for the 255 * SPI flash chip - we will bind to the correct driver. 256 */ 257 if (ret == -ENODEV && drv_name) { 258 struct dm_spi_slave_platdata *plat; 259 260 debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n", 261 __func__, dev_name, busnum, cs, drv_name); 262 ret = device_bind_driver(bus, drv_name, dev_name, &dev); 263 if (ret) 264 return ret; 265 plat = dev_get_parent_platdata(dev); 266 plat->cs = cs; 267 plat->max_hz = speed; 268 plat->mode = mode; 269 created = true; 270 } else if (ret) { 271 printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs, 272 ret); 273 return ret; 274 } 275 276 if (!device_active(dev)) { 277 struct spi_slave *slave; 278 279 ret = device_probe(dev); 280 if (ret) 281 goto err; 282 slave = dev_get_parentdata(dev); 283 slave->dev = dev; 284 } 285 286 ret = spi_set_speed_mode(bus, speed, mode); 287 if (ret) 288 goto err; 289 290 *busp = bus; 291 *devp = dev_get_parentdata(dev); 292 debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp); 293 294 return 0; 295 296 err: 297 debug("%s: Error path, credted=%d, device '%s'\n", __func__, 298 created, dev->name); 299 if (created) { 300 device_remove(dev); 301 device_unbind(dev); 302 } 303 304 return ret; 305 } 306 307 /* Compatibility function - to be removed */ 308 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node, 309 int bus_node) 310 { 311 struct udevice *bus, *dev; 312 int ret; 313 314 ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus); 315 if (ret) 316 return NULL; 317 ret = device_get_child_by_of_offset(bus, node, &dev); 318 if (ret) 319 return NULL; 320 return dev_get_parentdata(dev); 321 } 322 323 /* Compatibility function - to be removed */ 324 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs, 325 unsigned int speed, unsigned int mode) 326 { 327 struct spi_slave *slave; 328 struct udevice *dev; 329 int ret; 330 331 ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev, 332 &slave); 333 if (ret) 334 return NULL; 335 336 return slave; 337 } 338 339 void spi_free_slave(struct spi_slave *slave) 340 { 341 device_remove(slave->dev); 342 slave->dev = NULL; 343 } 344 345 int spi_slave_ofdata_to_platdata(const void *blob, int node, 346 struct dm_spi_slave_platdata *plat) 347 { 348 int mode = 0; 349 350 plat->cs = fdtdec_get_int(blob, node, "reg", -1); 351 plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0); 352 if (fdtdec_get_bool(blob, node, "spi-cpol")) 353 mode |= SPI_CPOL; 354 if (fdtdec_get_bool(blob, node, "spi-cpha")) 355 mode |= SPI_CPHA; 356 if (fdtdec_get_bool(blob, node, "spi-cs-high")) 357 mode |= SPI_CS_HIGH; 358 if (fdtdec_get_bool(blob, node, "spi-half-duplex")) 359 mode |= SPI_PREAMBLE; 360 plat->mode = mode; 361 362 return 0; 363 } 364 365 UCLASS_DRIVER(spi) = { 366 .id = UCLASS_SPI, 367 .name = "spi", 368 .flags = DM_UC_FLAG_SEQ_ALIAS, 369 .post_bind = spi_post_bind, 370 .post_probe = spi_post_probe, 371 .child_pre_probe = spi_child_pre_probe, 372 .per_device_auto_alloc_size = sizeof(struct dm_spi_bus), 373 .per_child_auto_alloc_size = sizeof(struct spi_slave), 374 .per_child_platdata_auto_alloc_size = 375 sizeof(struct dm_spi_slave_platdata), 376 .child_post_bind = spi_child_post_bind, 377 }; 378 379 UCLASS_DRIVER(spi_generic) = { 380 .id = UCLASS_SPI_GENERIC, 381 .name = "spi_generic", 382 }; 383 384 U_BOOT_DRIVER(spi_generic_drv) = { 385 .name = "spi_generic_drv", 386 .id = UCLASS_SPI_GENERIC, 387 }; 388