saa7164-bus.c revision 207b42c492cc335806957c139381eb260a808837
1/* 2 * Driver for the NXP SAA7164 PCIe bridge 3 * 4 * Copyright (c) 2009 Steven Toth <stoth@kernellabs.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 20 */ 21 22#include "saa7164.h" 23 24/* The message bus to/from the firmware is a ring buffer in PCI address 25 * space. Establish the defaults. 26 */ 27int saa7164_bus_setup(struct saa7164_dev *dev) 28{ 29 tmComResBusInfo_t *b = &dev->bus; 30 31 mutex_init(&b->lock); 32 33 b->Type = TYPE_BUS_PCIe; 34 b->m_wMaxReqSize = SAA_DEVICE_MAXREQUESTSIZE; 35 36 b->m_pdwSetRing = (u8 *)(dev->bmmio + 37 ((u32)dev->busdesc.CommandRing)); 38 39 b->m_dwSizeSetRing = SAA_DEVICE_BUFFERBLOCKSIZE; 40 41 b->m_pdwGetRing = (u8 *)(dev->bmmio + 42 ((u32)dev->busdesc.ResponseRing)); 43 44 b->m_dwSizeGetRing = SAA_DEVICE_BUFFERBLOCKSIZE; 45 46 b->m_pdwSetWritePos = (u32 *)((u8 *)(dev->bmmio + 47 ((u32)dev->intfdesc.BARLocation) + (2 * sizeof(u64)))); 48 49 b->m_pdwSetReadPos = (u32 *)((u8 *)b->m_pdwSetWritePos + 50 1 * sizeof(u32)); 51 52 b->m_pdwGetWritePos = (u32 *)((u8 *)b->m_pdwSetWritePos + 53 2 * sizeof(u32)); 54 55 b->m_pdwGetReadPos = (u32 *)((u8 *)b->m_pdwSetWritePos + 56 3 * sizeof(u32)); 57 58 return 0; 59} 60 61void saa7164_bus_dump(struct saa7164_dev *dev) 62{ 63 tmComResBusInfo_t *b = &dev->bus; 64 65 dprintk(DBGLVL_BUS, "Dumping the bus structure:\n"); 66 dprintk(DBGLVL_BUS, " .type = %d\n", b->Type); 67 dprintk(DBGLVL_BUS, " .dev->bmmio = 0x%p\n", dev->bmmio); 68 dprintk(DBGLVL_BUS, " .m_wMaxReqSize = 0x%x\n", b->m_wMaxReqSize); 69 dprintk(DBGLVL_BUS, " .m_pdwSetRing = 0x%p\n", b->m_pdwSetRing); 70 dprintk(DBGLVL_BUS, " .m_dwSizeSetRing = 0x%x\n", b->m_dwSizeSetRing); 71 dprintk(DBGLVL_BUS, " .m_pdwGetRing = 0x%p\n", b->m_pdwGetRing); 72 dprintk(DBGLVL_BUS, " .m_dwSizeGetRing = 0x%x\n", b->m_dwSizeGetRing); 73 74 dprintk(DBGLVL_BUS, " .m_pdwSetWritePos = 0x%p (0x%08x)\n", 75 b->m_pdwSetWritePos, *b->m_pdwSetWritePos); 76 77 dprintk(DBGLVL_BUS, " .m_pdwSetReadPos = 0x%p (0x%08x)\n", 78 b->m_pdwSetReadPos, *b->m_pdwSetReadPos); 79 80 dprintk(DBGLVL_BUS, " .m_pdwGetWritePos = 0x%p (0x%08x)\n", 81 b->m_pdwGetWritePos, *b->m_pdwGetWritePos); 82 83 dprintk(DBGLVL_BUS, " .m_pdwGetReadPos = 0x%p (0x%08x)\n", 84 b->m_pdwGetReadPos, *b->m_pdwGetReadPos); 85} 86 87void saa7164_bus_dumpmsg(struct saa7164_dev *dev, tmComResInfo_t* m, void *buf) 88{ 89 dprintk(DBGLVL_BUS, "Dumping msg structure:\n"); 90 dprintk(DBGLVL_BUS, " .id = %d\n", m->id); 91 dprintk(DBGLVL_BUS, " .flags = 0x%x\n", m->flags); 92 dprintk(DBGLVL_BUS, " .size = 0x%x\n", m->size); 93 dprintk(DBGLVL_BUS, " .command = 0x%x\n", m->command); 94 dprintk(DBGLVL_BUS, " .controlselector = 0x%x\n", m->controlselector); 95 dprintk(DBGLVL_BUS, " .seqno = %d\n", m->seqno); 96 if (buf) 97 dprintk(DBGLVL_BUS, " .buffer (ignored)\n"); 98} 99 100/* 101 * Places a command or a response on the bus. The implementation does not 102 * know if it is a command or a response it just places the data on the 103 * bus depending on the bus information given in the tmComResBusInfo_t 104 * structure. If the command or response does not fit into the bus ring 105 * buffer it will be refused. 106 * 107 * Return Value: 108 * SAA_OK The function executed successfully. 109 * < 0 One or more members are not initialized. 110 */ 111int saa7164_bus_set(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf) 112{ 113 tmComResBusInfo_t *bus = &dev->bus; 114 u32 bytes_to_write, read_distance, timeout, curr_srp, curr_swp; 115 u32 new_swp, space_rem; 116 int ret = SAA_ERR_BAD_PARAMETER; 117 118 if (!msg) { 119 printk(KERN_ERR "%s() !msg\n", __func__); 120 return SAA_ERR_BAD_PARAMETER; 121 } 122 123 dprintk(DBGLVL_BUS, "%s()\n", __func__); 124 125 msg->size = cpu_to_le16(msg->size); 126 msg->command = cpu_to_le16(msg->command); 127 msg->controlselector = cpu_to_le16(msg->controlselector); 128 129 if (msg->size > dev->bus.m_wMaxReqSize) { 130 printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n", 131 __func__); 132 return SAA_ERR_BAD_PARAMETER; 133 } 134 135 if ((msg->size > 0) && (buf == 0)) { 136 printk(KERN_ERR "%s() Missing message buffer\n", __func__); 137 return SAA_ERR_BAD_PARAMETER; 138 } 139 140 /* Lock the bus from any other access */ 141 mutex_lock(&bus->lock); 142 143 bytes_to_write = sizeof(*msg) + msg->size; 144 read_distance = 0; 145 timeout = SAA_BUS_TIMEOUT; 146 curr_srp = le32_to_cpu(*bus->m_pdwSetReadPos); 147 curr_swp = le32_to_cpu(*bus->m_pdwSetWritePos); 148 149 /* Deal with ring wrapping issues */ 150 if (curr_srp > curr_swp) 151 /* The ring has not wrapped yet */ 152 read_distance = curr_srp - curr_swp; 153 else 154 /* Deal with the wrapped ring */ 155 read_distance = (curr_srp + bus->m_dwSizeSetRing) - curr_swp; 156 157 dprintk(DBGLVL_BUS, "%s() bytes_to_write = %d\n", __func__, 158 bytes_to_write); 159 160 dprintk(DBGLVL_BUS, "%s() read_distance = %d\n", __func__, 161 read_distance); 162 163 dprintk(DBGLVL_BUS, "%s() curr_srp = %x\n", __func__, curr_srp); 164 dprintk(DBGLVL_BUS, "%s() curr_swp = %x\n", __func__, curr_swp); 165 166 /* Process the msg and write the content onto the bus */ 167 while (bytes_to_write >= read_distance) { 168 169 if (timeout-- == 0) { 170 printk(KERN_ERR "%s() bus timeout\n", __func__); 171 ret = SAA_ERR_NO_RESOURCES; 172 goto out; 173 } 174 175 /* TODO: Review this delay, efficient? */ 176 /* Wait, allowing the hardware fetch time */ 177 mdelay(1); 178 179 /* Check the space usage again */ 180 curr_srp = le32_to_cpu(*bus->m_pdwSetReadPos); 181 182 /* Deal with ring wrapping issues */ 183 if (curr_srp > curr_swp) 184 /* Read didn't wrap around the buffer */ 185 read_distance = curr_srp - curr_swp; 186 else 187 /* Deal with the wrapped ring */ 188 read_distance = (curr_srp + bus->m_dwSizeSetRing) - 189 curr_swp; 190 191 } 192 193 /* Calculate the new write position */ 194 new_swp = curr_swp + bytes_to_write; 195 196 dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp); 197 dprintk(DBGLVL_BUS, "%s() bus->m_dwSizeSetRing = %x\n", __func__, 198 bus->m_dwSizeSetRing); 199 200 /* Mental Note: line 462 tmmhComResBusPCIe.cpp */ 201 202 /* Check if we're going to wrap again */ 203 if (new_swp > bus->m_dwSizeSetRing) { 204 205 /* Ring wraps */ 206 new_swp -= bus->m_dwSizeSetRing; 207 208 space_rem = bus->m_dwSizeSetRing - curr_swp; 209 210 dprintk(DBGLVL_BUS, "%s() space_rem = %x\n", __func__, 211 space_rem); 212 213 dprintk(DBGLVL_BUS, "%s() sizeof(*msg) = %d\n", __func__, 214 (u32)sizeof(*msg)); 215 216 if (space_rem < sizeof(*msg)) { 217 dprintk(DBGLVL_BUS, "%s() tr4\n", __func__); 218 219 /* Split the msg into pieces as the ring wraps */ 220 memcpy(bus->m_pdwSetRing + curr_swp, msg, space_rem); 221 memcpy(bus->m_pdwSetRing, (u8 *)msg + space_rem, 222 sizeof(*msg) - space_rem); 223 224 memcpy(bus->m_pdwSetRing + sizeof(*msg) - space_rem, 225 buf, msg->size); 226 227 } else if (space_rem == sizeof(*msg)) { 228 dprintk(DBGLVL_BUS, "%s() tr5\n", __func__); 229 230 /* Additional data at the beginning of the ring */ 231 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 232 memcpy(bus->m_pdwSetRing, buf, msg->size); 233 234 } else { 235 /* Additional data wraps around the ring */ 236 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 237 if (msg->size > 0) { 238 memcpy(bus->m_pdwSetRing + curr_swp + 239 sizeof(*msg), buf, space_rem - 240 sizeof(*msg)); 241 memcpy(bus->m_pdwSetRing, (u8 *)buf + 242 space_rem - sizeof(*msg), 243 bytes_to_write - space_rem); 244 } 245 246 } 247 248 } /* (new_swp > bus->m_dwSizeSetRing) */ 249 else { 250 dprintk(DBGLVL_BUS, "%s() tr6\n", __func__); 251 252 /* The ring buffer doesn't wrap, two simple copies */ 253 memcpy(bus->m_pdwSetRing + curr_swp, msg, sizeof(*msg)); 254 memcpy(bus->m_pdwSetRing + curr_swp + sizeof(*msg), buf, 255 msg->size); 256 } 257 258 dprintk(DBGLVL_BUS, "%s() new_swp = %x\n", __func__, new_swp); 259 260 /* TODO: Convert all of the volatiles and direct PCI writes into 261 * saa7164_writel/b calls for consistency. 262 */ 263 264 /* Update the bus write position */ 265 *bus->m_pdwSetWritePos = cpu_to_le32(new_swp); 266 ret = SAA_OK; 267 268out: 269 mutex_unlock(&bus->lock); 270 return ret; 271} 272 273/* 274 * Receive a command or a response from the bus. The implementation does not 275 * know if it is a command or a response it simply dequeues the data, 276 * depending on the bus information given in the tmComResBusInfo_t structure. 277 * 278 * Return Value: 279 * 0 The function executed successfully. 280 * < 0 One or more members are not initialized. 281 */ 282int saa7164_bus_get(struct saa7164_dev *dev, tmComResInfo_t* msg, void *buf, 283 int peekonly) 284{ 285 tmComResBusInfo_t *bus = &dev->bus; 286 u32 bytes_to_read, write_distance, curr_grp, curr_gwp, 287 new_grp, buf_size, space_rem; 288 tmComResInfo_t msg_tmp; 289 int ret = SAA_ERR_BAD_PARAMETER; 290 291 if (msg == 0) 292 return ret; 293 294 if (msg->size > dev->bus.m_wMaxReqSize) { 295 printk(KERN_ERR "%s() Exceeded dev->bus.m_wMaxReqSize\n", 296 __func__); 297 return ret; 298 } 299 300 if ((peekonly == 0) && (msg->size > 0) && (buf == 0)) { 301 printk(KERN_ERR 302 "%s() Missing msg buf, size should be %d bytes\n", 303 __func__, msg->size); 304 return ret; 305 } 306 307 mutex_lock(&bus->lock); 308 309 /* Peek the bus to see if a msg exists, if it's not what we're expecting 310 * then return cleanly else read the message from the bus. 311 */ 312 curr_gwp = le32_to_cpu(*bus->m_pdwGetWritePos); 313 curr_grp = le32_to_cpu(*bus->m_pdwGetReadPos); 314 315 if (curr_gwp == curr_grp) { 316 dprintk(DBGLVL_BUS, "%s() No message on the bus\n", __func__); 317 ret = SAA_ERR_EMPTY; 318 goto out; 319 } 320 321 bytes_to_read = sizeof(*msg); 322 323 /* Calculate write distance to current read position */ 324 write_distance = 0; 325 if (curr_gwp >= curr_grp) 326 /* Write doesn't wrap around the ring */ 327 write_distance = curr_gwp - curr_grp; 328 else 329 /* Write wraps around the ring */ 330 write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; 331 332 if (bytes_to_read > write_distance) { 333 printk(KERN_ERR "%s() No message/response found\n", __func__); 334 ret = SAA_ERR_INVALID_COMMAND; 335 goto out; 336 } 337 338 /* Calculate the new read position */ 339 new_grp = curr_grp + bytes_to_read; 340 if (new_grp > bus->m_dwSizeGetRing) { 341 342 /* Ring wraps */ 343 new_grp -= bus->m_dwSizeGetRing; 344 space_rem = bus->m_dwSizeGetRing - curr_grp; 345 346 memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, space_rem); 347 memcpy((u8 *)&msg_tmp + space_rem, bus->m_pdwGetRing, 348 bytes_to_read - space_rem); 349 350 } else { 351 /* No wrapping */ 352 memcpy(&msg_tmp, bus->m_pdwGetRing + curr_grp, bytes_to_read); 353 } 354 355 /* No need to update the read positions, because this was a peek */ 356 /* If the caller specifically want to peek, return */ 357 if (peekonly) { 358 memcpy(msg, &msg_tmp, sizeof(*msg)); 359 goto peekout; 360 } 361 362 /* Check if the command/response matches what is expected */ 363 if ((msg_tmp.id != msg->id) || (msg_tmp.command != msg->command) || 364 (msg_tmp.controlselector != msg->controlselector) || 365 (msg_tmp.seqno != msg->seqno) || (msg_tmp.size != msg->size)) { 366 367 printk(KERN_ERR "%s() Unexpected msg miss-match\n", __func__); 368 saa7164_bus_dumpmsg(dev, msg, buf); 369 saa7164_bus_dumpmsg(dev, &msg_tmp, 0); 370 ret = SAA_ERR_INVALID_COMMAND; 371 goto out; 372 } 373 374 /* Get the actual command and response from the bus */ 375 buf_size = msg->size; 376 377 bytes_to_read = sizeof(*msg) + msg->size; 378 /* Calculate write distance to current read position */ 379 write_distance = 0; 380 if (curr_gwp >= curr_grp) 381 /* Write doesn't wrap around the ring */ 382 write_distance = curr_gwp - curr_grp; 383 else 384 /* Write wraps around the ring */ 385 write_distance = curr_gwp + bus->m_dwSizeGetRing - curr_grp; 386 387 if (bytes_to_read > write_distance) { 388 printk(KERN_ERR "%s() Invalid bus state, missing msg " 389 "or mangled ring, faulty H/W / bad code?\n", __func__); 390 ret = SAA_ERR_INVALID_COMMAND; 391 goto out; 392 } 393 394 /* Calculate the new read position */ 395 new_grp = curr_grp + bytes_to_read; 396 if (new_grp > bus->m_dwSizeGetRing) { 397 398 /* Ring wraps */ 399 new_grp -= bus->m_dwSizeGetRing; 400 space_rem = bus->m_dwSizeGetRing - curr_grp; 401 402 if (space_rem < sizeof(*msg)) { 403 /* msg wraps around the ring */ 404 memcpy(msg, bus->m_pdwGetRing + curr_grp, space_rem); 405 memcpy((u8 *)msg + space_rem, bus->m_pdwGetRing, 406 sizeof(*msg) - space_rem); 407 if (buf) 408 memcpy(buf, bus->m_pdwGetRing + sizeof(*msg) - 409 space_rem, buf_size); 410 411 } else if (space_rem == sizeof(*msg)) { 412 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); 413 if (buf) 414 memcpy(buf, bus->m_pdwGetRing, buf_size); 415 } else { 416 /* Additional data wraps around the ring */ 417 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); 418 if (buf) { 419 memcpy(buf, bus->m_pdwGetRing + curr_grp + 420 sizeof(*msg), space_rem - sizeof(*msg)); 421 memcpy(buf + space_rem - sizeof(*msg), 422 bus->m_pdwGetRing, bytes_to_read - 423 space_rem); 424 } 425 426 } 427 428 } else { 429 /* No wrapping */ 430 memcpy(msg, bus->m_pdwGetRing + curr_grp, sizeof(*msg)); 431 if (buf) 432 memcpy(buf, bus->m_pdwGetRing + curr_grp + sizeof(*msg), 433 buf_size); 434 } 435 436 /* Update the read positions, adjusting the ring */ 437 *bus->m_pdwGetReadPos = cpu_to_le32(new_grp); 438 439peekout: 440 msg->size = le16_to_cpu(msg->size); 441 msg->command = le16_to_cpu(msg->command); 442 msg->controlselector = le16_to_cpu(msg->controlselector); 443 ret = SAA_OK; 444out: 445 mutex_unlock(&bus->lock); 446 return ret; 447} 448 449