1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Lattice MachXO2 Slave SPI Driver 4 * 5 * Manage Lattice FPGA firmware that is loaded over SPI using 6 * the slave serial configuration interface. 7 * 8 * Copyright (C) 2018 Paolo Pisati <p.pisati@gmail.com> 9 */ 10 11 #include <linux/delay.h> 12 #include <linux/fpga/fpga-mgr.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/spi/spi.h> 17 18 /* MachXO2 Programming Guide - sysCONFIG Programming Commands */ 19 #define IDCODE_PUB {0xe0, 0x00, 0x00, 0x00} 20 #define ISC_ENABLE {0xc6, 0x08, 0x00, 0x00} 21 #define ISC_ERASE {0x0e, 0x04, 0x00, 0x00} 22 #define ISC_PROGRAMDONE {0x5e, 0x00, 0x00, 0x00} 23 #define LSC_INITADDRESS {0x46, 0x00, 0x00, 0x00} 24 #define LSC_PROGINCRNV {0x70, 0x00, 0x00, 0x01} 25 #define LSC_READ_STATUS {0x3c, 0x00, 0x00, 0x00} 26 #define LSC_REFRESH {0x79, 0x00, 0x00, 0x00} 27 28 /* 29 * Max CCLK in Slave SPI mode according to 'MachXO2 Family Data 30 * Sheet' sysCONFIG Port Timing Specifications (3-36) 31 */ 32 #define MACHXO2_MAX_SPEED 66000000 33 34 #define MACHXO2_LOW_DELAY_USEC 5 35 #define MACHXO2_HIGH_DELAY_USEC 200 36 #define MACHXO2_REFRESH_USEC 4800 37 #define MACHXO2_MAX_BUSY_LOOP 128 38 #define MACHXO2_MAX_REFRESH_LOOP 16 39 40 #define MACHXO2_PAGE_SIZE 16 41 #define MACHXO2_BUF_SIZE (MACHXO2_PAGE_SIZE + 4) 42 43 /* Status register bits, errors and error mask */ 44 #define BUSY 12 45 #define DONE 8 46 #define DVER 27 47 #define ENAB 9 48 #define ERRBITS 23 49 #define ERRMASK 7 50 #define FAIL 13 51 52 #define ENOERR 0 /* no error */ 53 #define EID 1 54 #define ECMD 2 55 #define ECRC 3 56 #define EPREAM 4 /* preamble error */ 57 #define EABRT 5 /* abort error */ 58 #define EOVERFL 6 /* overflow error */ 59 #define ESDMEOF 7 /* SDM EOF */ 60 61 static inline u8 get_err(unsigned long *status) 62 { 63 return (*status >> ERRBITS) & ERRMASK; 64 } 65 66 static int get_status(struct spi_device *spi, unsigned long *status) 67 { 68 struct spi_message msg; 69 struct spi_transfer rx, tx; 70 static const u8 cmd[] = LSC_READ_STATUS; 71 int ret; 72 73 memset(&rx, 0, sizeof(rx)); 74 memset(&tx, 0, sizeof(tx)); 75 tx.tx_buf = cmd; 76 tx.len = sizeof(cmd); 77 rx.rx_buf = status; 78 rx.len = 4; 79 spi_message_init(&msg); 80 spi_message_add_tail(&tx, &msg); 81 spi_message_add_tail(&rx, &msg); 82 ret = spi_sync(spi, &msg); 83 if (ret) 84 return ret; 85 86 *status = be32_to_cpu(*status); 87 88 return 0; 89 } 90 91 #ifdef DEBUG 92 static const char *get_err_string(u8 err) 93 { 94 switch (err) { 95 case ENOERR: return "No Error"; 96 case EID: return "ID ERR"; 97 case ECMD: return "CMD ERR"; 98 case ECRC: return "CRC ERR"; 99 case EPREAM: return "Preamble ERR"; 100 case EABRT: return "Abort ERR"; 101 case EOVERFL: return "Overflow ERR"; 102 case ESDMEOF: return "SDM EOF"; 103 } 104 105 return "Default switch case"; 106 } 107 #endif 108 109 static void dump_status_reg(unsigned long *status) 110 { 111 #ifdef DEBUG 112 pr_debug("machxo2 status: 0x%08lX - done=%d, cfgena=%d, busy=%d, fail=%d, devver=%d, err=%s\n", 113 *status, test_bit(DONE, status), test_bit(ENAB, status), 114 test_bit(BUSY, status), test_bit(FAIL, status), 115 test_bit(DVER, status), get_err_string(get_err(status))); 116 #endif 117 } 118 119 static int wait_until_not_busy(struct spi_device *spi) 120 { 121 unsigned long status; 122 int ret, loop = 0; 123 124 do { 125 ret = get_status(spi, &status); 126 if (ret) 127 return ret; 128 if (++loop >= MACHXO2_MAX_BUSY_LOOP) 129 return -EBUSY; 130 } while (test_bit(BUSY, &status)); 131 132 return 0; 133 } 134 135 static int machxo2_cleanup(struct fpga_manager *mgr) 136 { 137 struct spi_device *spi = mgr->priv; 138 struct spi_message msg; 139 struct spi_transfer tx[2]; 140 static const u8 erase[] = ISC_ERASE; 141 static const u8 refresh[] = LSC_REFRESH; 142 int ret; 143 144 memset(tx, 0, sizeof(tx)); 145 spi_message_init(&msg); 146 tx[0].tx_buf = &erase; 147 tx[0].len = sizeof(erase); 148 spi_message_add_tail(&tx[0], &msg); 149 ret = spi_sync(spi, &msg); 150 if (ret) 151 goto fail; 152 153 ret = wait_until_not_busy(spi); 154 if (ret) 155 goto fail; 156 157 spi_message_init(&msg); 158 tx[1].tx_buf = &refresh; 159 tx[1].len = sizeof(refresh); 160 tx[1].delay.value = MACHXO2_REFRESH_USEC; 161 tx[1].delay.unit = SPI_DELAY_UNIT_USECS; 162 spi_message_add_tail(&tx[1], &msg); 163 ret = spi_sync(spi, &msg); 164 if (ret) 165 goto fail; 166 167 return 0; 168 fail: 169 dev_err(&mgr->dev, "Cleanup failed\n"); 170 171 return ret; 172 } 173 174 static enum fpga_mgr_states machxo2_spi_state(struct fpga_manager *mgr) 175 { 176 struct spi_device *spi = mgr->priv; 177 unsigned long status; 178 179 get_status(spi, &status); 180 if (!test_bit(BUSY, &status) && test_bit(DONE, &status) && 181 get_err(&status) == ENOERR) 182 return FPGA_MGR_STATE_OPERATING; 183 184 return FPGA_MGR_STATE_UNKNOWN; 185 } 186 187 static int machxo2_write_init(struct fpga_manager *mgr, 188 struct fpga_image_info *info, 189 const char *buf, size_t count) 190 { 191 struct spi_device *spi = mgr->priv; 192 struct spi_message msg; 193 struct spi_transfer tx[3]; 194 static const u8 enable[] = ISC_ENABLE; 195 static const u8 erase[] = ISC_ERASE; 196 static const u8 initaddr[] = LSC_INITADDRESS; 197 unsigned long status; 198 int ret; 199 200 if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) { 201 dev_err(&mgr->dev, 202 "Partial reconfiguration is not supported\n"); 203 return -ENOTSUPP; 204 } 205 206 get_status(spi, &status); 207 dump_status_reg(&status); 208 memset(tx, 0, sizeof(tx)); 209 spi_message_init(&msg); 210 tx[0].tx_buf = &enable; 211 tx[0].len = sizeof(enable); 212 tx[0].delay.value = MACHXO2_LOW_DELAY_USEC; 213 tx[0].delay.unit = SPI_DELAY_UNIT_USECS; 214 spi_message_add_tail(&tx[0], &msg); 215 216 tx[1].tx_buf = &erase; 217 tx[1].len = sizeof(erase); 218 spi_message_add_tail(&tx[1], &msg); 219 ret = spi_sync(spi, &msg); 220 if (ret) 221 goto fail; 222 223 ret = wait_until_not_busy(spi); 224 if (ret) 225 goto fail; 226 227 get_status(spi, &status); 228 if (test_bit(FAIL, &status)) { 229 ret = -EINVAL; 230 goto fail; 231 } 232 dump_status_reg(&status); 233 234 spi_message_init(&msg); 235 tx[2].tx_buf = &initaddr; 236 tx[2].len = sizeof(initaddr); 237 spi_message_add_tail(&tx[2], &msg); 238 ret = spi_sync(spi, &msg); 239 if (ret) 240 goto fail; 241 242 get_status(spi, &status); 243 dump_status_reg(&status); 244 245 return 0; 246 fail: 247 dev_err(&mgr->dev, "Error during FPGA init.\n"); 248 249 return ret; 250 } 251 252 static int machxo2_write(struct fpga_manager *mgr, const char *buf, 253 size_t count) 254 { 255 struct spi_device *spi = mgr->priv; 256 struct spi_message msg; 257 struct spi_transfer tx; 258 static const u8 progincr[] = LSC_PROGINCRNV; 259 u8 payload[MACHXO2_BUF_SIZE]; 260 unsigned long status; 261 int i, ret; 262 263 if (count % MACHXO2_PAGE_SIZE != 0) { 264 dev_err(&mgr->dev, "Malformed payload.\n"); 265 return -EINVAL; 266 } 267 get_status(spi, &status); 268 dump_status_reg(&status); 269 memcpy(payload, &progincr, sizeof(progincr)); 270 for (i = 0; i < count; i += MACHXO2_PAGE_SIZE) { 271 memcpy(&payload[sizeof(progincr)], &buf[i], MACHXO2_PAGE_SIZE); 272 memset(&tx, 0, sizeof(tx)); 273 spi_message_init(&msg); 274 tx.tx_buf = payload; 275 tx.len = MACHXO2_BUF_SIZE; 276 tx.delay.value = MACHXO2_HIGH_DELAY_USEC; 277 tx.delay.unit = SPI_DELAY_UNIT_USECS; 278 spi_message_add_tail(&tx, &msg); 279 ret = spi_sync(spi, &msg); 280 if (ret) { 281 dev_err(&mgr->dev, "Error loading the bitstream.\n"); 282 return ret; 283 } 284 } 285 get_status(spi, &status); 286 dump_status_reg(&status); 287 288 return 0; 289 } 290 291 static int machxo2_write_complete(struct fpga_manager *mgr, 292 struct fpga_image_info *info) 293 { 294 struct spi_device *spi = mgr->priv; 295 struct spi_message msg; 296 struct spi_transfer tx[2]; 297 static const u8 progdone[] = ISC_PROGRAMDONE; 298 static const u8 refresh[] = LSC_REFRESH; 299 unsigned long status; 300 int ret, refreshloop = 0; 301 302 memset(tx, 0, sizeof(tx)); 303 spi_message_init(&msg); 304 tx[0].tx_buf = &progdone; 305 tx[0].len = sizeof(progdone); 306 spi_message_add_tail(&tx[0], &msg); 307 ret = spi_sync(spi, &msg); 308 if (ret) 309 goto fail; 310 ret = wait_until_not_busy(spi); 311 if (ret) 312 goto fail; 313 314 get_status(spi, &status); 315 dump_status_reg(&status); 316 if (!test_bit(DONE, &status)) { 317 machxo2_cleanup(mgr); 318 ret = -EINVAL; 319 goto fail; 320 } 321 322 do { 323 spi_message_init(&msg); 324 tx[1].tx_buf = &refresh; 325 tx[1].len = sizeof(refresh); 326 tx[1].delay.value = MACHXO2_REFRESH_USEC; 327 tx[1].delay.unit = SPI_DELAY_UNIT_USECS; 328 spi_message_add_tail(&tx[1], &msg); 329 ret = spi_sync(spi, &msg); 330 if (ret) 331 goto fail; 332 333 /* check refresh status */ 334 get_status(spi, &status); 335 dump_status_reg(&status); 336 if (!test_bit(BUSY, &status) && test_bit(DONE, &status) && 337 get_err(&status) == ENOERR) 338 break; 339 if (++refreshloop == MACHXO2_MAX_REFRESH_LOOP) { 340 machxo2_cleanup(mgr); 341 ret = -EINVAL; 342 goto fail; 343 } 344 } while (1); 345 346 get_status(spi, &status); 347 dump_status_reg(&status); 348 349 return 0; 350 fail: 351 dev_err(&mgr->dev, "Refresh failed.\n"); 352 353 return ret; 354 } 355 356 static const struct fpga_manager_ops machxo2_ops = { 357 .state = machxo2_spi_state, 358 .write_init = machxo2_write_init, 359 .write = machxo2_write, 360 .write_complete = machxo2_write_complete, 361 }; 362 363 static int machxo2_spi_probe(struct spi_device *spi) 364 { 365 struct device *dev = &spi->dev; 366 struct fpga_manager *mgr; 367 368 if (spi->max_speed_hz > MACHXO2_MAX_SPEED) { 369 dev_err(dev, "Speed is too high\n"); 370 return -EINVAL; 371 } 372 373 mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager", 374 &machxo2_ops, spi); 375 if (!mgr) 376 return -ENOMEM; 377 378 return devm_fpga_mgr_register(dev, mgr); 379 } 380 381 #ifdef CONFIG_OF 382 static const struct of_device_id of_match[] = { 383 { .compatible = "lattice,machxo2-slave-spi", }, 384 {} 385 }; 386 MODULE_DEVICE_TABLE(of, of_match); 387 #endif 388 389 static const struct spi_device_id lattice_ids[] = { 390 { "machxo2-slave-spi", 0 }, 391 { }, 392 }; 393 MODULE_DEVICE_TABLE(spi, lattice_ids); 394 395 static struct spi_driver machxo2_spi_driver = { 396 .driver = { 397 .name = "machxo2-slave-spi", 398 .of_match_table = of_match_ptr(of_match), 399 }, 400 .probe = machxo2_spi_probe, 401 .id_table = lattice_ids, 402 }; 403 404 module_spi_driver(machxo2_spi_driver) 405 406 MODULE_AUTHOR("Paolo Pisati <p.pisati@gmail.com>"); 407 MODULE_DESCRIPTION("Load Lattice FPGA firmware over SPI"); 408 MODULE_LICENSE("GPL v2"); 409