1 #include <linux/kernel.h> 2 #include <linux/module.h> 3 #include <linux/slab.h> 4 #include <linux/delay.h> 5 #include <linux/ioport.h> 6 #include <linux/mtd/mtd.h> 7 #include <linux/platform_device.h> 8 #include <linux/bcma/bcma.h> 9 10 #include "bcm47xxsflash.h" 11 12 MODULE_LICENSE("GPL"); 13 MODULE_DESCRIPTION("Serial flash driver for BCMA bus"); 14 15 static const char * const probes[] = { "bcm47xxpart", NULL }; 16 17 /************************************************** 18 * Various helpers 19 **************************************************/ 20 21 static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode) 22 { 23 int i; 24 25 b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode); 26 for (i = 0; i < 1000; i++) { 27 if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) & 28 BCMA_CC_FLASHCTL_BUSY)) 29 return; 30 cpu_relax(); 31 } 32 pr_err("Control command failed (timeout)!\n"); 33 } 34 35 static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout) 36 { 37 unsigned long deadline = jiffies + timeout; 38 39 do { 40 switch (b47s->type) { 41 case BCM47XXSFLASH_TYPE_ST: 42 bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR); 43 if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) & 44 SR_ST_WIP)) 45 return 0; 46 break; 47 case BCM47XXSFLASH_TYPE_ATMEL: 48 bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS); 49 if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) & 50 SR_AT_READY) 51 return 0; 52 break; 53 } 54 55 cpu_relax(); 56 udelay(1); 57 } while (!time_after_eq(jiffies, deadline)); 58 59 pr_err("Timeout waiting for flash to be ready!\n"); 60 61 return -EBUSY; 62 } 63 64 /************************************************** 65 * MTD ops 66 **************************************************/ 67 68 static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase) 69 { 70 struct bcm47xxsflash *b47s = mtd->priv; 71 int err; 72 73 switch (b47s->type) { 74 case BCM47XXSFLASH_TYPE_ST: 75 bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN); 76 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr); 77 /* Newer flashes have "sub-sectors" which can be erased 78 * independently with a new command: ST_SSE. The ST_SE command 79 * erases 64KB just as before. 80 */ 81 if (b47s->blocksize < (64 * 1024)) 82 bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE); 83 else 84 bcm47xxsflash_cmd(b47s, OPCODE_ST_SE); 85 break; 86 case BCM47XXSFLASH_TYPE_ATMEL: 87 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1); 88 bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE); 89 break; 90 } 91 92 err = bcm47xxsflash_poll(b47s, HZ); 93 if (err) 94 erase->state = MTD_ERASE_FAILED; 95 else 96 erase->state = MTD_ERASE_DONE; 97 98 if (erase->callback) 99 erase->callback(erase); 100 101 return err; 102 } 103 104 static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len, 105 size_t *retlen, u_char *buf) 106 { 107 struct bcm47xxsflash *b47s = mtd->priv; 108 109 /* Check address range */ 110 if ((from + len) > mtd->size) 111 return -EINVAL; 112 113 memcpy_fromio(buf, b47s->window + from, len); 114 *retlen = len; 115 116 return len; 117 } 118 119 static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len, 120 const u_char *buf) 121 { 122 struct bcm47xxsflash *b47s = mtd->priv; 123 int written = 0; 124 125 /* Enable writes */ 126 bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN); 127 128 /* Write first byte */ 129 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset); 130 b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++); 131 132 /* Program page */ 133 if (b47s->bcma_cc->core->id.rev < 20) { 134 bcm47xxsflash_cmd(b47s, OPCODE_ST_PP); 135 return 1; /* 1B written */ 136 } 137 138 /* Program page and set CSA (on newer chips we can continue writing) */ 139 bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP); 140 offset++; 141 len--; 142 written++; 143 144 while (len > 0) { 145 /* Page boundary, another function call is needed */ 146 if ((offset & 0xFF) == 0) 147 break; 148 149 bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++); 150 offset++; 151 len--; 152 written++; 153 } 154 155 /* All done, drop CSA & poll */ 156 b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0); 157 udelay(1); 158 if (bcm47xxsflash_poll(b47s, HZ / 10)) 159 pr_err("Flash rejected dropping CSA\n"); 160 161 return written; 162 } 163 164 static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len, 165 const u_char *buf) 166 { 167 struct bcm47xxsflash *b47s = mtd->priv; 168 u32 mask = b47s->blocksize - 1; 169 u32 page = (offset & ~mask) << 1; 170 u32 byte = offset & mask; 171 int written = 0; 172 173 /* If we don't overwrite whole page, read it to the buffer first */ 174 if (byte || (len < b47s->blocksize)) { 175 int err; 176 177 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page); 178 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD); 179 /* 250 us for AT45DB321B */ 180 err = bcm47xxsflash_poll(b47s, HZ / 1000); 181 if (err) { 182 pr_err("Timeout reading page 0x%X info buffer\n", page); 183 return err; 184 } 185 } 186 187 /* Change buffer content with our data */ 188 while (len > 0) { 189 /* Page boundary, another function call is needed */ 190 if (byte == b47s->blocksize) 191 break; 192 193 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++); 194 b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++); 195 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE); 196 len--; 197 written++; 198 } 199 200 /* Program page with the buffer content */ 201 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page); 202 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM); 203 204 return written; 205 } 206 207 static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len, 208 size_t *retlen, const u_char *buf) 209 { 210 struct bcm47xxsflash *b47s = mtd->priv; 211 int written; 212 213 /* Writing functions can return without writing all passed data, for 214 * example when the hardware is too old or when we git page boundary. 215 */ 216 while (len > 0) { 217 switch (b47s->type) { 218 case BCM47XXSFLASH_TYPE_ST: 219 written = bcm47xxsflash_write_st(mtd, to, len, buf); 220 break; 221 case BCM47XXSFLASH_TYPE_ATMEL: 222 written = bcm47xxsflash_write_at(mtd, to, len, buf); 223 break; 224 default: 225 BUG_ON(1); 226 } 227 if (written < 0) { 228 pr_err("Error writing at offset 0x%llX\n", to); 229 return written; 230 } 231 to += (loff_t)written; 232 len -= written; 233 *retlen += written; 234 buf += written; 235 } 236 237 return 0; 238 } 239 240 static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s, 241 struct device *dev) 242 { 243 struct mtd_info *mtd = &b47s->mtd; 244 245 mtd->priv = b47s; 246 mtd->dev.parent = dev; 247 mtd->name = "bcm47xxsflash"; 248 249 mtd->type = MTD_NORFLASH; 250 mtd->flags = MTD_CAP_NORFLASH; 251 mtd->size = b47s->size; 252 mtd->erasesize = b47s->blocksize; 253 mtd->writesize = 1; 254 mtd->writebufsize = 1; 255 256 mtd->_erase = bcm47xxsflash_erase; 257 mtd->_read = bcm47xxsflash_read; 258 mtd->_write = bcm47xxsflash_write; 259 } 260 261 /************************************************** 262 * BCMA 263 **************************************************/ 264 265 static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset) 266 { 267 return bcma_cc_read32(b47s->bcma_cc, offset); 268 } 269 270 static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset, 271 u32 value) 272 { 273 bcma_cc_write32(b47s->bcma_cc, offset, value); 274 } 275 276 static int bcm47xxsflash_bcma_probe(struct platform_device *pdev) 277 { 278 struct device *dev = &pdev->dev; 279 struct bcma_sflash *sflash = dev_get_platdata(dev); 280 struct bcm47xxsflash *b47s; 281 struct resource *res; 282 int err; 283 284 b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL); 285 if (!b47s) 286 return -ENOMEM; 287 sflash->priv = b47s; 288 289 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 290 if (!res) { 291 dev_err(dev, "invalid resource\n"); 292 return -EINVAL; 293 } 294 if (!devm_request_mem_region(dev, res->start, resource_size(res), 295 res->name)) { 296 dev_err(dev, "can't request region for resource %pR\n", res); 297 return -EBUSY; 298 } 299 b47s->window = ioremap_cache(res->start, resource_size(res)); 300 if (!b47s->window) { 301 dev_err(dev, "ioremap failed for resource %pR\n", res); 302 return -ENOMEM; 303 } 304 305 b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash); 306 b47s->cc_read = bcm47xxsflash_bcma_cc_read; 307 b47s->cc_write = bcm47xxsflash_bcma_cc_write; 308 309 switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) { 310 case BCMA_CC_FLASHT_STSER: 311 b47s->type = BCM47XXSFLASH_TYPE_ST; 312 break; 313 case BCMA_CC_FLASHT_ATSER: 314 b47s->type = BCM47XXSFLASH_TYPE_ATMEL; 315 break; 316 } 317 318 b47s->blocksize = sflash->blocksize; 319 b47s->numblocks = sflash->numblocks; 320 b47s->size = sflash->size; 321 bcm47xxsflash_fill_mtd(b47s, &pdev->dev); 322 323 err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0); 324 if (err) { 325 pr_err("Failed to register MTD device: %d\n", err); 326 iounmap(b47s->window); 327 return err; 328 } 329 330 if (bcm47xxsflash_poll(b47s, HZ / 10)) 331 pr_warn("Serial flash busy\n"); 332 333 return 0; 334 } 335 336 static int bcm47xxsflash_bcma_remove(struct platform_device *pdev) 337 { 338 struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev); 339 struct bcm47xxsflash *b47s = sflash->priv; 340 341 mtd_device_unregister(&b47s->mtd); 342 iounmap(b47s->window); 343 344 return 0; 345 } 346 347 static struct platform_driver bcma_sflash_driver = { 348 .probe = bcm47xxsflash_bcma_probe, 349 .remove = bcm47xxsflash_bcma_remove, 350 .driver = { 351 .name = "bcma_sflash", 352 }, 353 }; 354 355 /************************************************** 356 * Init 357 **************************************************/ 358 359 module_platform_driver(bcma_sflash_driver); 360