drivers/fpga/lattice-sysconfig.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Lattice FPGA sysCONFIG interface functions independent of port type.
   4  */
   5
   6 #include <linux/delay.h>
   7 #include <linux/fpga/fpga-mgr.h>
   8 #include <linux/gpio/consumer.h>
   9 #include <linux/iopoll.h>
  10
  11 #include "lattice-sysconfig.h"
  12
  13 static int sysconfig_cmd_write(struct sysconfig_priv *priv, const void *buf,
  14                                size_t buf_len)
  15 {
  16         return priv->command_transfer(priv, buf, buf_len, NULL, 0);
  17 }
  18
  19 static int sysconfig_cmd_read(struct sysconfig_priv *priv, const void *tx_buf,
  20                               size_t tx_len, void *rx_buf, size_t rx_len)
  21 {
  22         return priv->command_transfer(priv, tx_buf, tx_len, rx_buf, rx_len);
  23 }
  24
  25 static int sysconfig_read_busy(struct sysconfig_priv *priv)
  26 {
  27         const u8 lsc_check_busy[] = SYSCONFIG_LSC_CHECK_BUSY;
  28         u8 busy;
  29         int ret;
  30
  31         ret = sysconfig_cmd_read(priv, lsc_check_busy, sizeof(lsc_check_busy),
  32                                  &busy, sizeof(busy));
  33
  34         return ret ? : busy;
  35 }
  36
  37 static int sysconfig_poll_busy(struct sysconfig_priv *priv)
  38 {
  39         int ret, busy;
  40
  41         ret = read_poll_timeout(sysconfig_read_busy, busy, busy <= 0,
  42                                 SYSCONFIG_POLL_INTERVAL_US,
  43                                 SYSCONFIG_POLL_BUSY_TIMEOUT_US, false, priv);
  44
  45         return ret ? : busy;
  46 }
  47
  48 static int sysconfig_read_status(struct sysconfig_priv *priv, u32 *status)
  49 {
  50         const u8 lsc_read_status[] = SYSCONFIG_LSC_READ_STATUS;
  51         __be32 device_status;
  52         int ret;
  53
  54         ret = sysconfig_cmd_read(priv, lsc_read_status, sizeof(lsc_read_status),
  55                                  &device_status, sizeof(device_status));
  56         if (ret)
  57                 return ret;
  58
  59         *status = be32_to_cpu(device_status);
  60
  61         return 0;
  62 }
  63
  64 static int sysconfig_poll_status(struct sysconfig_priv *priv, u32 *status)
  65 {
  66         int ret = sysconfig_poll_busy(priv);
  67
  68         if (ret)
  69                 return ret;
  70
  71         return sysconfig_read_status(priv, status);
  72 }
  73
  74 static int sysconfig_poll_gpio(struct gpio_desc *gpio, bool is_active)
  75 {
  76         int ret, val;
  77
  78         ret = read_poll_timeout(gpiod_get_value, val,
  79                                 val < 0 || !!val == is_active,
  80                                 SYSCONFIG_POLL_INTERVAL_US,
  81                                 SYSCONFIG_POLL_GPIO_TIMEOUT_US, false, gpio);
  82
  83         if (val < 0)
  84                 return val;
  85
  86         return ret;
  87 }
  88
  89 static int sysconfig_gpio_refresh(struct sysconfig_priv *priv)
  90 {
  91         struct gpio_desc *program = priv->program;
  92         struct gpio_desc *init = priv->init;
  93         struct gpio_desc *done = priv->done;
  94         int ret;
  95
  96         /* Enter init mode */
  97         gpiod_set_value(program, 1);
  98
  99         ret = sysconfig_poll_gpio(init, true);
 100         if (!ret)
 101                 ret = sysconfig_poll_gpio(done, false);
 102
 103         if (ret)
 104                 return ret;
 105
 106         /* Enter program mode */
 107         gpiod_set_value(program, 0);
 108
 109         return sysconfig_poll_gpio(init, false);
 110 }
 111
 112 static int sysconfig_lsc_refresh(struct sysconfig_priv *priv)
 113 {
 114         static const u8 lsc_refresh[] = SYSCONFIG_LSC_REFRESH;
 115         int ret;
 116
 117         ret = sysconfig_cmd_write(priv, lsc_refresh, sizeof(lsc_refresh));
 118         if (ret)
 119                 return ret;
 120
 121         usleep_range(4000, 8000);
 122
 123         return 0;
 124 }
 125
 126 static int sysconfig_refresh(struct sysconfig_priv *priv)
 127 {
 128         struct gpio_desc *program = priv->program;
 129         struct gpio_desc *init = priv->init;
 130         struct gpio_desc *done = priv->done;
 131
 132         if (program && init && done)
 133                 return sysconfig_gpio_refresh(priv);
 134
 135         return sysconfig_lsc_refresh(priv);
 136 }
 137
 138 static int sysconfig_isc_enable(struct sysconfig_priv *priv)
 139 {
 140         u8 isc_enable[] = SYSCONFIG_ISC_ENABLE;
 141         u32 status;
 142         int ret;
 143
 144         ret = sysconfig_cmd_write(priv, isc_enable, sizeof(isc_enable));
 145         if (ret)
 146                 return ret;
 147
 148         ret = sysconfig_poll_status(priv, &status);
 149         if (ret)
 150                 return ret;
 151
 152         if (status & SYSCONFIG_STATUS_FAIL)
 153                 return -EFAULT;
 154
 155         return 0;
 156 }
 157
 158 static int sysconfig_isc_erase(struct sysconfig_priv *priv)
 159 {
 160         u8 isc_erase[] = SYSCONFIG_ISC_ERASE;
 161         u32 status;
 162         int ret;
 163
 164         ret = sysconfig_cmd_write(priv, isc_erase, sizeof(isc_erase));
 165         if (ret)
 166                 return ret;
 167
 168         ret = sysconfig_poll_status(priv, &status);
 169         if (ret)
 170                 return ret;
 171
 172         if (status & SYSCONFIG_STATUS_FAIL)
 173                 return -EFAULT;
 174
 175         return 0;
 176 }
 177
 178 static int sysconfig_isc_init(struct sysconfig_priv *priv)
 179 {
 180         int ret = sysconfig_isc_enable(priv);
 181
 182         if (ret)
 183                 return ret;
 184
 185         return sysconfig_isc_erase(priv);
 186 }
 187
 188 static int sysconfig_lsc_init_addr(struct sysconfig_priv *priv)
 189 {
 190         const u8 lsc_init_addr[] = SYSCONFIG_LSC_INIT_ADDR;
 191
 192         return sysconfig_cmd_write(priv, lsc_init_addr, sizeof(lsc_init_addr));
 193 }
 194
 195 static int sysconfig_burst_write_init(struct sysconfig_priv *priv)
 196 {
 197         return priv->bitstream_burst_write_init(priv);
 198 }
 199
 200 static int sysconfig_burst_write_complete(struct sysconfig_priv *priv)
 201 {
 202         return priv->bitstream_burst_write_complete(priv);
 203 }
 204
 205 static int sysconfig_bitstream_burst_write(struct sysconfig_priv *priv,
 206                                            const char *buf, size_t count)
 207 {
 208         int ret = priv->bitstream_burst_write(priv, buf, count);
 209
 210         if (ret)
 211                 sysconfig_burst_write_complete(priv);
 212
 213         return ret;
 214 }
 215
 216 static int sysconfig_isc_disable(struct sysconfig_priv *priv)
 217 {
 218         const u8 isc_disable[] = SYSCONFIG_ISC_DISABLE;
 219
 220         return sysconfig_cmd_write(priv, isc_disable, sizeof(isc_disable));
 221 }
 222
 223 static void sysconfig_cleanup(struct sysconfig_priv *priv)
 224 {
 225         sysconfig_isc_erase(priv);
 226         sysconfig_refresh(priv);
 227 }
 228
 229 static int sysconfig_isc_finish(struct sysconfig_priv *priv)
 230 {
 231         struct gpio_desc *done_gpio = priv->done;
 232         u32 status;
 233         int ret;
 234
 235         if (done_gpio) {
 236                 ret = sysconfig_isc_disable(priv);
 237                 if (ret)
 238                         return ret;
 239
 240                 return sysconfig_poll_gpio(done_gpio, true);
 241         }
 242
 243         ret = sysconfig_poll_status(priv, &status);
 244         if (ret)
 245                 return ret;
 246
 247         if ((status & SYSCONFIG_STATUS_DONE) &&
 248             !(status & SYSCONFIG_STATUS_BUSY) &&
 249             !(status & SYSCONFIG_STATUS_ERR))
 250                 return sysconfig_isc_disable(priv);
 251
 252         return -EFAULT;
 253 }
 254
 255 static enum fpga_mgr_states sysconfig_ops_state(struct fpga_manager *mgr)
 256 {
 257         struct sysconfig_priv *priv = mgr->priv;
 258         struct gpio_desc *done = priv->done;
 259         u32 status;
 260         int ret;
 261
 262         if (done && (gpiod_get_value(done) > 0))
 263                 return FPGA_MGR_STATE_OPERATING;
 264
 265         ret = sysconfig_read_status(priv, &status);
 266         if (!ret && (status & SYSCONFIG_STATUS_DONE))
 267                 return FPGA_MGR_STATE_OPERATING;
 268
 269         return FPGA_MGR_STATE_UNKNOWN;
 270 }
 271
 272 static int sysconfig_ops_write_init(struct fpga_manager *mgr,
 273                                     struct fpga_image_info *info,
 274                                     const char *buf, size_t count)
 275 {
 276         struct sysconfig_priv *priv = mgr->priv;
 277         struct device *dev = &mgr->dev;
 278         int ret;
 279
 280         if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
 281                 dev_err(dev, "Partial reconfiguration is not supported\n");
 282                 return -EOPNOTSUPP;
 283         }
 284
 285         /* Enter program mode */
 286         ret = sysconfig_refresh(priv);
 287         if (ret) {
 288                 dev_err(dev, "Failed to go to program mode\n");
 289                 return ret;
 290         }
 291
 292         /* Enter ISC mode */
 293         ret = sysconfig_isc_init(priv);
 294         if (ret) {
 295                 dev_err(dev, "Failed to go to ISC mode\n");
 296                 return ret;
 297         }
 298
 299         /* Initialize the Address Shift Register */
 300         ret = sysconfig_lsc_init_addr(priv);
 301         if (ret) {
 302                 dev_err(dev,
 303                         "Failed to initialize the Address Shift Register\n");
 304                 return ret;
 305         }
 306
 307         /* Prepare for bitstream burst write */
 308         ret = sysconfig_burst_write_init(priv);
 309         if (ret)
 310                 dev_err(dev, "Failed to prepare for bitstream burst write\n");
 311
 312         return ret;
 313 }
 314
 315 static int sysconfig_ops_write(struct fpga_manager *mgr, const char *buf,
 316                                size_t count)
 317 {
 318         return sysconfig_bitstream_burst_write(mgr->priv, buf, count);
 319 }
 320
 321 static int sysconfig_ops_write_complete(struct fpga_manager *mgr,
 322                                         struct fpga_image_info *info)
 323 {
 324         struct sysconfig_priv *priv = mgr->priv;
 325         struct device *dev = &mgr->dev;
 326         int ret;
 327
 328         ret = sysconfig_burst_write_complete(priv);
 329         if (!ret)
 330                 ret = sysconfig_poll_busy(priv);
 331
 332         if (ret) {
 333                 dev_err(dev, "Error while waiting bitstream write to finish\n");
 334                 goto fail;
 335         }
 336
 337         ret = sysconfig_isc_finish(priv);
 338
 339 fail:
 340         if (ret)
 341                 sysconfig_cleanup(priv);
 342
 343         return ret;
 344 }
 345
 346 static const struct fpga_manager_ops sysconfig_fpga_mgr_ops = {
 347         .state = sysconfig_ops_state,
 348         .write_init = sysconfig_ops_write_init,
 349         .write = sysconfig_ops_write,
 350         .write_complete = sysconfig_ops_write_complete,
 351 };
 352
 353 int sysconfig_probe(struct sysconfig_priv *priv)
 354 {
 355         struct gpio_desc *program, *init, *done;
 356         struct device *dev = priv->dev;
 357         struct fpga_manager *mgr;
 358
 359         if (!dev)
 360                 return -ENODEV;
 361
 362         if (!priv->command_transfer ||
 363             !priv->bitstream_burst_write_init ||
 364             !priv->bitstream_burst_write ||
 365             !priv->bitstream_burst_write_complete) {
 366                 dev_err(dev, "Essential callback is missing\n");
 367                 return -EINVAL;
 368         }
 369
 370         program = devm_gpiod_get_optional(dev, "program", GPIOD_OUT_LOW);
 371         if (IS_ERR(program))
 372                 return dev_err_probe(dev, PTR_ERR(program),
 373                                      "Failed to get PROGRAM GPIO\n");
 374
 375         init = devm_gpiod_get_optional(dev, "init", GPIOD_IN);
 376         if (IS_ERR(init))
 377                 return dev_err_probe(dev, PTR_ERR(init),
 378                                      "Failed to get INIT GPIO\n");
 379
 380         done = devm_gpiod_get_optional(dev, "done", GPIOD_IN);
 381         if (IS_ERR(done))
 382                 return dev_err_probe(dev, PTR_ERR(done),
 383                                      "Failed to get DONE GPIO\n");
 384
 385         priv->program = program;
 386         priv->init = init;
 387         priv->done = done;
 388
 389         mgr = devm_fpga_mgr_register(dev, "Lattice sysCONFIG FPGA Manager",
 390                                      &sysconfig_fpga_mgr_ops, priv);
 391
 392         return PTR_ERR_OR_ZERO(mgr);
 393 }
 394 EXPORT_SYMBOL(sysconfig_probe);
 395
 396 MODULE_DESCRIPTION("Lattice sysCONFIG FPGA Manager Core");
 397 MODULE_LICENSE("GPL");