drivers/spi/spi-uclass.c

   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 = dev_get_uclass_priv(bus);
  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         if (speed != slave->speed) {
  67                 ret = spi_set_speed_mode(bus, speed, slave->mode);
  68                 if (ret)
  69                         return ret;
  70                 slave->speed = speed;
  71         }
  72
  73         return ops->claim_bus ? ops->claim_bus(dev) : 0;
  74 }
  75
  76 void spi_release_bus(struct spi_slave *slave)
  77 {
  78         struct udevice *dev = slave->dev;
  79         struct udevice *bus = dev->parent;
  80         struct dm_spi_ops *ops = spi_get_ops(bus);
  81
  82         if (ops->release_bus)
  83                 ops->release_bus(dev);
  84 }
  85
  86 int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
  87              const void *dout, void *din, unsigned long flags)
  88 {
  89         struct udevice *dev = slave->dev;
  90         struct udevice *bus = dev->parent;
  91
  92         if (bus->uclass->uc_drv->id != UCLASS_SPI)
  93                 return -EOPNOTSUPP;
  94
  95         return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
  96 }
  97
  98 int spi_post_bind(struct udevice *dev)
  99 {
 100         /* Scan the bus for devices */
 101         return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
 102 }
 103
 104 int spi_child_post_bind(struct udevice *dev)
 105 {
 106         struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
 107
 108         if (dev->of_offset == -1)
 109                 return 0;
 110
 111         return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
 112 }
 113
 114 int spi_post_probe(struct udevice *bus)
 115 {
 116         struct dm_spi_bus *spi = dev_get_uclass_priv(bus);
 117
 118         spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
 119                                      "spi-max-frequency", 0);
 120
 121         return 0;
 122 }
 123
 124 int spi_child_pre_probe(struct udevice *dev)
 125 {
 126         struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
 127         struct spi_slave *slave = dev_get_parentdata(dev);
 128
 129         /*
 130          * This is needed because we pass struct spi_slave around the place
 131          * instead slave->dev (a struct udevice). So we have to have some
 132          * way to access the slave udevice given struct spi_slave. Once we
 133          * change the SPI API to use udevice instead of spi_slave, we can
 134          * drop this.
 135          */
 136         slave->dev = dev;
 137
 138         slave->max_hz = plat->max_hz;
 139         slave->mode = plat->mode;
 140
 141         return 0;
 142 }
 143
 144 int spi_chip_select(struct udevice *dev)
 145 {
 146         struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
 147
 148         return plat ? plat->cs : -ENOENT;
 149 }
 150
 151 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
 152 {
 153         struct udevice *dev;
 154
 155         for (device_find_first_child(bus, &dev); dev;
 156              device_find_next_child(&dev)) {
 157                 struct dm_spi_slave_platdata *plat;
 158
 159                 plat = dev_get_parent_platdata(dev);
 160                 debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
 161                 if (plat->cs == cs) {
 162                         *devp = dev;
 163                         return 0;
 164                 }
 165         }
 166
 167         return -ENODEV;
 168 }
 169
 170 int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
 171 {
 172         struct spi_cs_info info;
 173         struct udevice *bus;
 174         int ret;
 175
 176         ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
 177         if (ret) {
 178                 debug("%s: No bus %d\n", __func__, busnum);
 179                 return ret;
 180         }
 181
 182         return spi_cs_info(bus, cs, &info);
 183 }
 184
 185 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
 186 {
 187         struct spi_cs_info local_info;
 188         struct dm_spi_ops *ops;
 189         int ret;
 190
 191         if (!info)
 192                 info = &local_info;
 193
 194         /* If there is a device attached, return it */
 195         info->dev = NULL;
 196         ret = spi_find_chip_select(bus, cs, &info->dev);
 197         if (!ret)
 198                 return 0;
 199
 200         /*
 201          * Otherwise ask the driver. For the moment we don't have CS info.
 202          * When we do we could provide the driver with a helper function
 203          * to figure out what chip selects are valid, or just handle the
 204          * request.
 205          */
 206         ops = spi_get_ops(bus);
 207         if (ops->cs_info)
 208                 return ops->cs_info(bus, cs, info);
 209
 210         /*
 211          * We could assume there is at least one valid chip select, but best
 212          * to be sure and return an error in this case. The driver didn't
 213          * care enough to tell us.
 214          */
 215         return -ENODEV;
 216 }
 217
 218 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
 219                         struct udevice **devp)
 220 {
 221         struct udevice *bus, *dev;
 222         int ret;
 223
 224         ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
 225         if (ret) {
 226                 debug("%s: No bus %d\n", __func__, busnum);
 227                 return ret;
 228         }
 229         ret = spi_find_chip_select(bus, cs, &dev);
 230         if (ret) {
 231                 debug("%s: No cs %d\n", __func__, cs);
 232                 return ret;
 233         }
 234         *busp = bus;
 235         *devp = dev;
 236
 237         return ret;
 238 }
 239
 240 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
 241                        const char *drv_name, const char *dev_name,
 242                        struct udevice **busp, struct spi_slave **devp)
 243 {
 244         struct udevice *bus, *dev;
 245         bool created = false;
 246         int ret;
 247
 248         ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
 249         if (ret) {
 250                 printf("Invalid bus %d (err=%d)\n", busnum, ret);
 251                 return ret;
 252         }
 253         ret = spi_find_chip_select(bus, cs, &dev);
 254
 255         /*
 256          * If there is no such device, create one automatically. This means
 257          * that we don't need a device tree node or platform data for the
 258          * SPI flash chip - we will bind to the correct driver.
 259          */
 260         if (ret == -ENODEV && drv_name) {
 261                 struct dm_spi_slave_platdata *plat;
 262
 263                 debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
 264                       __func__, dev_name, busnum, cs, drv_name);
 265                 ret = device_bind_driver(bus, drv_name, dev_name, &dev);
 266                 if (ret)
 267                         return ret;
 268                 plat = dev_get_parent_platdata(dev);
 269                 plat->cs = cs;
 270                 plat->max_hz = speed;
 271                 plat->mode = mode;
 272                 created = true;
 273         } else if (ret) {
 274                 printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
 275                        ret);
 276                 return ret;
 277         }
 278
 279         if (!device_active(dev)) {
 280                 struct spi_slave *slave;
 281
 282                 ret = device_probe(dev);
 283                 if (ret)
 284                         goto err;
 285                 slave = dev_get_parentdata(dev);
 286                 slave->dev = dev;
 287         }
 288
 289         ret = spi_set_speed_mode(bus, speed, mode);
 290         if (ret)
 291                 goto err;
 292
 293         *busp = bus;
 294         *devp = dev_get_parentdata(dev);
 295         debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
 296
 297         return 0;
 298
 299 err:
 300         debug("%s: Error path, credted=%d, device '%s'\n", __func__,
 301               created, dev->name);
 302         if (created) {
 303                 device_remove(dev);
 304                 device_unbind(dev);
 305         }
 306
 307         return ret;
 308 }
 309
 310 /* Compatibility function - to be removed */
 311 struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
 312                                       int bus_node)
 313 {
 314         struct udevice *bus, *dev;
 315         int ret;
 316
 317         ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
 318         if (ret)
 319                 return NULL;
 320         ret = device_get_child_by_of_offset(bus, node, &dev);
 321         if (ret)
 322                 return NULL;
 323         return dev_get_parentdata(dev);
 324 }
 325
 326 /* Compatibility function - to be removed */
 327 struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
 328                                   unsigned int speed, unsigned int mode)
 329 {
 330         struct spi_slave *slave;
 331         struct udevice *dev;
 332         int ret;
 333
 334         ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
 335                                   &slave);
 336         if (ret)
 337                 return NULL;
 338
 339         return slave;
 340 }
 341
 342 void spi_free_slave(struct spi_slave *slave)
 343 {
 344         device_remove(slave->dev);
 345         slave->dev = NULL;
 346 }
 347
 348 int spi_slave_ofdata_to_platdata(const void *blob, int node,
 349                                  struct dm_spi_slave_platdata *plat)
 350 {
 351         int mode = 0;
 352
 353         plat->cs = fdtdec_get_int(blob, node, "reg", -1);
 354         plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
 355         if (fdtdec_get_bool(blob, node, "spi-cpol"))
 356                 mode |= SPI_CPOL;
 357         if (fdtdec_get_bool(blob, node, "spi-cpha"))
 358                 mode |= SPI_CPHA;
 359         if (fdtdec_get_bool(blob, node, "spi-cs-high"))
 360                 mode |= SPI_CS_HIGH;
 361         if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
 362                 mode |= SPI_PREAMBLE;
 363         plat->mode = mode;
 364
 365         return 0;
 366 }
 367
 368 UCLASS_DRIVER(spi) = {
 369         .id             = UCLASS_SPI,
 370         .name           = "spi",
 371         .flags          = DM_UC_FLAG_SEQ_ALIAS,
 372         .post_bind      = spi_post_bind,
 373         .post_probe     = spi_post_probe,
 374         .child_pre_probe = spi_child_pre_probe,
 375         .per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
 376         .per_child_auto_alloc_size = sizeof(struct spi_slave),
 377         .per_child_platdata_auto_alloc_size =
 378                         sizeof(struct dm_spi_slave_platdata),
 379         .child_post_bind = spi_child_post_bind,
 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 };