1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * 4 * Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com> 5 */ 6 7 #include <linux/module.h> 8 #include <linux/device.h> 9 #include <linux/platform_device.h> 10 #include <linux/spi/spi.h> 11 #include <linux/delay.h> 12 #include <linux/of.h> 13 #include <linux/of_platform.h> 14 15 #include <lantiq_soc.h> 16 17 #define DRV_NAME "sflash-falcon" 18 19 #define FALCON_SPI_XFER_BEGIN (1 << 0) 20 #define FALCON_SPI_XFER_END (1 << 1) 21 22 /* Bus Read Configuration Register0 */ 23 #define BUSRCON0 0x00000010 24 /* Bus Write Configuration Register0 */ 25 #define BUSWCON0 0x00000018 26 /* Serial Flash Configuration Register */ 27 #define SFCON 0x00000080 28 /* Serial Flash Time Register */ 29 #define SFTIME 0x00000084 30 /* Serial Flash Status Register */ 31 #define SFSTAT 0x00000088 32 /* Serial Flash Command Register */ 33 #define SFCMD 0x0000008C 34 /* Serial Flash Address Register */ 35 #define SFADDR 0x00000090 36 /* Serial Flash Data Register */ 37 #define SFDATA 0x00000094 38 /* Serial Flash I/O Control Register */ 39 #define SFIO 0x00000098 40 /* EBU Clock Control Register */ 41 #define EBUCC 0x000000C4 42 43 /* Dummy Phase Length */ 44 #define SFCMD_DUMLEN_OFFSET 16 45 #define SFCMD_DUMLEN_MASK 0x000F0000 46 /* Chip Select */ 47 #define SFCMD_CS_OFFSET 24 48 #define SFCMD_CS_MASK 0x07000000 49 /* field offset */ 50 #define SFCMD_ALEN_OFFSET 20 51 #define SFCMD_ALEN_MASK 0x00700000 52 /* SCK Rise-edge Position */ 53 #define SFTIME_SCKR_POS_OFFSET 8 54 #define SFTIME_SCKR_POS_MASK 0x00000F00 55 /* SCK Period */ 56 #define SFTIME_SCK_PER_OFFSET 0 57 #define SFTIME_SCK_PER_MASK 0x0000000F 58 /* SCK Fall-edge Position */ 59 #define SFTIME_SCKF_POS_OFFSET 12 60 #define SFTIME_SCKF_POS_MASK 0x0000F000 61 /* Device Size */ 62 #define SFCON_DEV_SIZE_A23_0 0x03000000 63 #define SFCON_DEV_SIZE_MASK 0x0F000000 64 /* Read Data Position */ 65 #define SFTIME_RD_POS_MASK 0x000F0000 66 /* Data Output */ 67 #define SFIO_UNUSED_WD_MASK 0x0000000F 68 /* Command Opcode mask */ 69 #define SFCMD_OPC_MASK 0x000000FF 70 /* dlen bytes of data to write */ 71 #define SFCMD_DIR_WRITE 0x00000100 72 /* Data Length offset */ 73 #define SFCMD_DLEN_OFFSET 9 74 /* Command Error */ 75 #define SFSTAT_CMD_ERR 0x20000000 76 /* Access Command Pending */ 77 #define SFSTAT_CMD_PEND 0x00400000 78 /* Frequency set to 100MHz. */ 79 #define EBUCC_EBUDIV_SELF100 0x00000001 80 /* Serial Flash */ 81 #define BUSRCON0_AGEN_SERIAL_FLASH 0xF0000000 82 /* 8-bit multiplexed */ 83 #define BUSRCON0_PORTW_8_BIT_MUX 0x00000000 84 /* Serial Flash */ 85 #define BUSWCON0_AGEN_SERIAL_FLASH 0xF0000000 86 /* Chip Select after opcode */ 87 #define SFCMD_KEEP_CS_KEEP_SELECTED 0x00008000 88 89 #define CLOCK_100M 100000000 90 #define CLOCK_50M 50000000 91 92 struct falcon_sflash { 93 u32 sfcmd; /* for caching of opcode, direction, ... */ 94 struct spi_controller *host; 95 }; 96 97 int falcon_sflash_xfer(struct spi_device *spi, struct spi_transfer *t, 98 unsigned long flags) 99 { 100 struct device *dev = &spi->dev; 101 struct falcon_sflash *priv = spi_controller_get_devdata(spi->controller); 102 const u8 *txp = t->tx_buf; 103 u8 *rxp = t->rx_buf; 104 unsigned int bytelen = ((8 * t->len + 7) / 8); 105 unsigned int len, alen, dumlen; 106 u32 val; 107 enum { 108 state_init, 109 state_command_prepare, 110 state_write, 111 state_read, 112 state_disable_cs, 113 state_end 114 } state = state_init; 115 116 do { 117 switch (state) { 118 case state_init: /* detect phase of upper layer sequence */ 119 { 120 /* initial write ? */ 121 if (flags & FALCON_SPI_XFER_BEGIN) { 122 if (!txp) { 123 dev_err(dev, 124 "BEGIN without tx data!\n"); 125 return -ENODATA; 126 } 127 /* 128 * Prepare the parts of the sfcmd register, 129 * which should not change during a sequence! 130 * Only exception are the length fields, 131 * especially alen and dumlen. 132 */ 133 134 priv->sfcmd = ((spi_get_chipselect(spi, 0) 135 << SFCMD_CS_OFFSET) 136 & SFCMD_CS_MASK); 137 priv->sfcmd |= SFCMD_KEEP_CS_KEEP_SELECTED; 138 priv->sfcmd |= *txp; 139 txp++; 140 bytelen--; 141 if (bytelen) { 142 /* 143 * more data: 144 * maybe address and/or dummy 145 */ 146 state = state_command_prepare; 147 break; 148 } else { 149 dev_dbg(dev, "write cmd %02X\n", 150 priv->sfcmd & SFCMD_OPC_MASK); 151 } 152 } 153 /* continued write ? */ 154 if (txp && bytelen) { 155 state = state_write; 156 break; 157 } 158 /* read data? */ 159 if (rxp && bytelen) { 160 state = state_read; 161 break; 162 } 163 /* end of sequence? */ 164 if (flags & FALCON_SPI_XFER_END) 165 state = state_disable_cs; 166 else 167 state = state_end; 168 break; 169 } 170 /* collect tx data for address and dummy phase */ 171 case state_command_prepare: 172 { 173 /* txp is valid, already checked */ 174 val = 0; 175 alen = 0; 176 dumlen = 0; 177 while (bytelen > 0) { 178 if (alen < 3) { 179 val = (val << 8) | (*txp++); 180 alen++; 181 } else if ((dumlen < 15) && (*txp == 0)) { 182 /* 183 * assume dummy bytes are set to 0 184 * from upper layer 185 */ 186 dumlen++; 187 txp++; 188 } else { 189 break; 190 } 191 bytelen--; 192 } 193 priv->sfcmd &= ~(SFCMD_ALEN_MASK | SFCMD_DUMLEN_MASK); 194 priv->sfcmd |= (alen << SFCMD_ALEN_OFFSET) | 195 (dumlen << SFCMD_DUMLEN_OFFSET); 196 if (alen > 0) 197 ltq_ebu_w32(val, SFADDR); 198 199 dev_dbg(dev, "wr %02X, alen=%d (addr=%06X) dlen=%d\n", 200 priv->sfcmd & SFCMD_OPC_MASK, 201 alen, val, dumlen); 202 203 if (bytelen > 0) { 204 /* continue with write */ 205 state = state_write; 206 } else if (flags & FALCON_SPI_XFER_END) { 207 /* end of sequence? */ 208 state = state_disable_cs; 209 } else { 210 /* 211 * go to end and expect another 212 * call (read or write) 213 */ 214 state = state_end; 215 } 216 break; 217 } 218 case state_write: 219 { 220 /* txp still valid */ 221 priv->sfcmd |= SFCMD_DIR_WRITE; 222 len = 0; 223 val = 0; 224 do { 225 if (bytelen--) 226 val |= (*txp++) << (8 * len++); 227 if ((flags & FALCON_SPI_XFER_END) 228 && (bytelen == 0)) { 229 priv->sfcmd &= 230 ~SFCMD_KEEP_CS_KEEP_SELECTED; 231 } 232 if ((len == 4) || (bytelen == 0)) { 233 ltq_ebu_w32(val, SFDATA); 234 ltq_ebu_w32(priv->sfcmd 235 | (len<<SFCMD_DLEN_OFFSET), 236 SFCMD); 237 len = 0; 238 val = 0; 239 priv->sfcmd &= ~(SFCMD_ALEN_MASK 240 | SFCMD_DUMLEN_MASK); 241 } 242 } while (bytelen); 243 state = state_end; 244 break; 245 } 246 case state_read: 247 { 248 /* read data */ 249 priv->sfcmd &= ~SFCMD_DIR_WRITE; 250 do { 251 if ((flags & FALCON_SPI_XFER_END) 252 && (bytelen <= 4)) { 253 priv->sfcmd &= 254 ~SFCMD_KEEP_CS_KEEP_SELECTED; 255 } 256 len = (bytelen > 4) ? 4 : bytelen; 257 bytelen -= len; 258 ltq_ebu_w32(priv->sfcmd 259 | (len << SFCMD_DLEN_OFFSET), SFCMD); 260 priv->sfcmd &= ~(SFCMD_ALEN_MASK 261 | SFCMD_DUMLEN_MASK); 262 do { 263 val = ltq_ebu_r32(SFSTAT); 264 if (val & SFSTAT_CMD_ERR) { 265 /* reset error status */ 266 dev_err(dev, "SFSTAT: CMD_ERR"); 267 dev_err(dev, " (%x)\n", val); 268 ltq_ebu_w32(SFSTAT_CMD_ERR, 269 SFSTAT); 270 return -EBADE; 271 } 272 } while (val & SFSTAT_CMD_PEND); 273 val = ltq_ebu_r32(SFDATA); 274 do { 275 *rxp = (val & 0xFF); 276 rxp++; 277 val >>= 8; 278 len--; 279 } while (len); 280 } while (bytelen); 281 state = state_end; 282 break; 283 } 284 case state_disable_cs: 285 { 286 priv->sfcmd &= ~SFCMD_KEEP_CS_KEEP_SELECTED; 287 ltq_ebu_w32(priv->sfcmd | (0 << SFCMD_DLEN_OFFSET), 288 SFCMD); 289 val = ltq_ebu_r32(SFSTAT); 290 if (val & SFSTAT_CMD_ERR) { 291 /* reset error status */ 292 dev_err(dev, "SFSTAT: CMD_ERR (%x)\n", val); 293 ltq_ebu_w32(SFSTAT_CMD_ERR, SFSTAT); 294 return -EBADE; 295 } 296 state = state_end; 297 break; 298 } 299 case state_end: 300 break; 301 } 302 } while (state != state_end); 303 304 return 0; 305 } 306 307 static int falcon_sflash_setup(struct spi_device *spi) 308 { 309 unsigned int i; 310 unsigned long flags; 311 312 spin_lock_irqsave(&ebu_lock, flags); 313 314 if (spi->max_speed_hz >= CLOCK_100M) { 315 /* set EBU clock to 100 MHz */ 316 ltq_sys1_w32_mask(0, EBUCC_EBUDIV_SELF100, EBUCC); 317 i = 1; /* divider */ 318 } else { 319 /* set EBU clock to 50 MHz */ 320 ltq_sys1_w32_mask(EBUCC_EBUDIV_SELF100, 0, EBUCC); 321 322 /* search for suitable divider */ 323 for (i = 1; i < 7; i++) { 324 if (CLOCK_50M / i <= spi->max_speed_hz) 325 break; 326 } 327 } 328 329 /* setup period of serial clock */ 330 ltq_ebu_w32_mask(SFTIME_SCKF_POS_MASK 331 | SFTIME_SCKR_POS_MASK 332 | SFTIME_SCK_PER_MASK, 333 (i << SFTIME_SCKR_POS_OFFSET) 334 | (i << (SFTIME_SCK_PER_OFFSET + 1)), 335 SFTIME); 336 337 /* 338 * set some bits of unused_wd, to not trigger HOLD/WP 339 * signals on non QUAD flashes 340 */ 341 ltq_ebu_w32((SFIO_UNUSED_WD_MASK & (0x8 | 0x4)), SFIO); 342 343 ltq_ebu_w32(BUSRCON0_AGEN_SERIAL_FLASH | BUSRCON0_PORTW_8_BIT_MUX, 344 BUSRCON0); 345 ltq_ebu_w32(BUSWCON0_AGEN_SERIAL_FLASH, BUSWCON0); 346 /* set address wrap around to maximum for 24-bit addresses */ 347 ltq_ebu_w32_mask(SFCON_DEV_SIZE_MASK, SFCON_DEV_SIZE_A23_0, SFCON); 348 349 spin_unlock_irqrestore(&ebu_lock, flags); 350 351 return 0; 352 } 353 354 static int falcon_sflash_xfer_one(struct spi_controller *host, 355 struct spi_message *m) 356 { 357 struct falcon_sflash *priv = spi_controller_get_devdata(host); 358 struct spi_transfer *t; 359 unsigned long spi_flags; 360 unsigned long flags; 361 int ret = 0; 362 363 priv->sfcmd = 0; 364 m->actual_length = 0; 365 366 spi_flags = FALCON_SPI_XFER_BEGIN; 367 list_for_each_entry(t, &m->transfers, transfer_list) { 368 if (list_is_last(&t->transfer_list, &m->transfers)) 369 spi_flags |= FALCON_SPI_XFER_END; 370 371 spin_lock_irqsave(&ebu_lock, flags); 372 ret = falcon_sflash_xfer(m->spi, t, spi_flags); 373 spin_unlock_irqrestore(&ebu_lock, flags); 374 375 if (ret) 376 break; 377 378 m->actual_length += t->len; 379 380 WARN_ON(t->delay.value || t->cs_change); 381 spi_flags = 0; 382 } 383 384 m->status = ret; 385 spi_finalize_current_message(host); 386 387 return 0; 388 } 389 390 static int falcon_sflash_probe(struct platform_device *pdev) 391 { 392 struct falcon_sflash *priv; 393 struct spi_controller *host; 394 int ret; 395 396 host = spi_alloc_host(&pdev->dev, sizeof(*priv)); 397 if (!host) 398 return -ENOMEM; 399 400 priv = spi_controller_get_devdata(host); 401 priv->host = host; 402 403 host->mode_bits = SPI_MODE_3; 404 host->flags = SPI_CONTROLLER_HALF_DUPLEX; 405 host->setup = falcon_sflash_setup; 406 host->transfer_one_message = falcon_sflash_xfer_one; 407 host->dev.of_node = pdev->dev.of_node; 408 409 ret = devm_spi_register_controller(&pdev->dev, host); 410 if (ret) 411 spi_controller_put(host); 412 return ret; 413 } 414 415 static const struct of_device_id falcon_sflash_match[] = { 416 { .compatible = "lantiq,sflash-falcon" }, 417 {}, 418 }; 419 MODULE_DEVICE_TABLE(of, falcon_sflash_match); 420 421 static struct platform_driver falcon_sflash_driver = { 422 .probe = falcon_sflash_probe, 423 .driver = { 424 .name = DRV_NAME, 425 .of_match_table = falcon_sflash_match, 426 } 427 }; 428 429 module_platform_driver(falcon_sflash_driver); 430 431 MODULE_LICENSE("GPL"); 432 MODULE_DESCRIPTION("Lantiq Falcon SPI/SFLASH controller driver"); 433