1 /* 2 * This program is free software; you can redistribute it and/or 3 * modify it under the terms of the GNU General Public License 4 * as published by the Free Software Foundation; either version 2 5 * of the License, or (at your option) any later version. 6 * 7 * This program is distributed in the hope that it will be useful, 8 * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 * GNU General Public License for more details. 11 * 12 * You should have received a copy of the GNU General Public License 13 * along with this program; if not, see <http://www.gnu.org/licenses/>. 14 */ 15 16 /** 17 * Both AR2315 and AR2316 chips have PCI interface unit, which supports DMA 18 * and interrupt. PCI interface supports MMIO access method, but does not 19 * seem to support I/O ports. 20 * 21 * Read/write operation in the region 0x80000000-0xBFFFFFFF causes 22 * a memory read/write command on the PCI bus. 30 LSBs of address on 23 * the bus are taken from memory read/write request and 2 MSBs are 24 * determined by PCI unit configuration. 25 * 26 * To work with the configuration space instead of memory is necessary set 27 * the CFG_SEL bit in the PCI_MISC_CONFIG register. 28 * 29 * Devices on the bus can perform DMA requests via chip BAR1. PCI host 30 * controller BARs are programmend as if an external device is programmed. 31 * Which means that during configuration, IDSEL pin of the chip should be 32 * asserted. 33 * 34 * We know (and support) only one board that uses the PCI interface - 35 * Fonera 2.0g (FON2202). It has a USB EHCI controller connected to the 36 * AR2315 PCI bus. IDSEL pin of USB controller is connected to AD[13] line 37 * and IDSEL pin of AR2315 is connected to AD[16] line. 38 */ 39 40 #include <linux/types.h> 41 #include <linux/pci.h> 42 #include <linux/platform_device.h> 43 #include <linux/kernel.h> 44 #include <linux/init.h> 45 #include <linux/mm.h> 46 #include <linux/delay.h> 47 #include <linux/bitops.h> 48 #include <linux/irq.h> 49 #include <linux/irqdomain.h> 50 #include <linux/io.h> 51 #include <asm/paccess.h> 52 53 /* 54 * PCI Bus Interface Registers 55 */ 56 #define AR2315_PCI_1MS_REG 0x0008 57 58 #define AR2315_PCI_1MS_MASK 0x3FFFF /* # of AHB clk cycles in 1ms */ 59 60 #define AR2315_PCI_MISC_CONFIG 0x000c 61 62 #define AR2315_PCIMISC_TXD_EN 0x00000001 /* Enable TXD for fragments */ 63 #define AR2315_PCIMISC_CFG_SEL 0x00000002 /* Mem or Config cycles */ 64 #define AR2315_PCIMISC_GIG_MASK 0x0000000C /* bits 31-30 for pci req */ 65 #define AR2315_PCIMISC_RST_MODE 0x00000030 66 #define AR2315_PCIRST_INPUT 0x00000000 /* 4:5=0 rst is input */ 67 #define AR2315_PCIRST_LOW 0x00000010 /* 4:5=1 rst to GND */ 68 #define AR2315_PCIRST_HIGH 0x00000020 /* 4:5=2 rst to VDD */ 69 #define AR2315_PCIGRANT_EN 0x00000000 /* 6:7=0 early grant en */ 70 #define AR2315_PCIGRANT_FRAME 0x00000040 /* 6:7=1 grant waits 4 frame */ 71 #define AR2315_PCIGRANT_IDLE 0x00000080 /* 6:7=2 grant waits 4 idle */ 72 #define AR2315_PCIGRANT_GAP 0x00000000 /* 6:7=2 grant waits 4 idle */ 73 #define AR2315_PCICACHE_DIS 0x00001000 /* PCI external access cache 74 * disable */ 75 76 #define AR2315_PCI_OUT_TSTAMP 0x0010 77 78 #define AR2315_PCI_UNCACHE_CFG 0x0014 79 80 #define AR2315_PCI_IN_EN 0x0100 81 82 #define AR2315_PCI_IN_EN0 0x01 /* Enable chain 0 */ 83 #define AR2315_PCI_IN_EN1 0x02 /* Enable chain 1 */ 84 #define AR2315_PCI_IN_EN2 0x04 /* Enable chain 2 */ 85 #define AR2315_PCI_IN_EN3 0x08 /* Enable chain 3 */ 86 87 #define AR2315_PCI_IN_DIS 0x0104 88 89 #define AR2315_PCI_IN_DIS0 0x01 /* Disable chain 0 */ 90 #define AR2315_PCI_IN_DIS1 0x02 /* Disable chain 1 */ 91 #define AR2315_PCI_IN_DIS2 0x04 /* Disable chain 2 */ 92 #define AR2315_PCI_IN_DIS3 0x08 /* Disable chain 3 */ 93 94 #define AR2315_PCI_IN_PTR 0x0200 95 96 #define AR2315_PCI_OUT_EN 0x0400 97 98 #define AR2315_PCI_OUT_EN0 0x01 /* Enable chain 0 */ 99 100 #define AR2315_PCI_OUT_DIS 0x0404 101 102 #define AR2315_PCI_OUT_DIS0 0x01 /* Disable chain 0 */ 103 104 #define AR2315_PCI_OUT_PTR 0x0408 105 106 /* PCI interrupt status (write one to clear) */ 107 #define AR2315_PCI_ISR 0x0500 108 109 #define AR2315_PCI_INT_TX 0x00000001 /* Desc In Completed */ 110 #define AR2315_PCI_INT_TXOK 0x00000002 /* Desc In OK */ 111 #define AR2315_PCI_INT_TXERR 0x00000004 /* Desc In ERR */ 112 #define AR2315_PCI_INT_TXEOL 0x00000008 /* Desc In End-of-List */ 113 #define AR2315_PCI_INT_RX 0x00000010 /* Desc Out Completed */ 114 #define AR2315_PCI_INT_RXOK 0x00000020 /* Desc Out OK */ 115 #define AR2315_PCI_INT_RXERR 0x00000040 /* Desc Out ERR */ 116 #define AR2315_PCI_INT_RXEOL 0x00000080 /* Desc Out EOL */ 117 #define AR2315_PCI_INT_TXOOD 0x00000200 /* Desc In Out-of-Desc */ 118 #define AR2315_PCI_INT_DESCMASK 0x0000FFFF /* Desc Mask */ 119 #define AR2315_PCI_INT_EXT 0x02000000 /* Extern PCI INTA */ 120 #define AR2315_PCI_INT_ABORT 0x04000000 /* PCI bus abort event */ 121 122 /* PCI interrupt mask */ 123 #define AR2315_PCI_IMR 0x0504 124 125 /* Global PCI interrupt enable */ 126 #define AR2315_PCI_IER 0x0508 127 128 #define AR2315_PCI_IER_DISABLE 0x00 /* disable pci interrupts */ 129 #define AR2315_PCI_IER_ENABLE 0x01 /* enable pci interrupts */ 130 131 #define AR2315_PCI_HOST_IN_EN 0x0800 132 #define AR2315_PCI_HOST_IN_DIS 0x0804 133 #define AR2315_PCI_HOST_IN_PTR 0x0810 134 #define AR2315_PCI_HOST_OUT_EN 0x0900 135 #define AR2315_PCI_HOST_OUT_DIS 0x0904 136 #define AR2315_PCI_HOST_OUT_PTR 0x0908 137 138 /* 139 * PCI interrupts, which share IP5 140 * Keep ordered according to AR2315_PCI_INT_XXX bits 141 */ 142 #define AR2315_PCI_IRQ_EXT 25 143 #define AR2315_PCI_IRQ_ABORT 26 144 #define AR2315_PCI_IRQ_COUNT 27 145 146 /* Arbitrary size of memory region to access the configuration space */ 147 #define AR2315_PCI_CFG_SIZE 0x00100000 148 149 #define AR2315_PCI_HOST_SLOT 3 150 #define AR2315_PCI_HOST_DEVID ((0xff18 << 16) | PCI_VENDOR_ID_ATHEROS) 151 152 /* ??? access BAR */ 153 #define AR2315_PCI_HOST_MBAR0 0x10000000 154 /* RAM access BAR */ 155 #define AR2315_PCI_HOST_MBAR1 AR2315_PCI_HOST_SDRAM_BASEADDR 156 /* ??? access BAR */ 157 #define AR2315_PCI_HOST_MBAR2 0x30000000 158 159 struct ar2315_pci_ctrl { 160 void __iomem *cfg_mem; 161 void __iomem *mmr_mem; 162 unsigned irq; 163 unsigned irq_ext; 164 struct irq_domain *domain; 165 struct pci_controller pci_ctrl; 166 struct resource mem_res; 167 struct resource io_res; 168 }; 169 170 static inline struct ar2315_pci_ctrl *ar2315_pci_bus_to_apc(struct pci_bus *bus) 171 { 172 struct pci_controller *hose = bus->sysdata; 173 174 return container_of(hose, struct ar2315_pci_ctrl, pci_ctrl); 175 } 176 177 static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg) 178 { 179 return __raw_readl(apc->mmr_mem + reg); 180 } 181 182 static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg, 183 u32 val) 184 { 185 __raw_writel(val, apc->mmr_mem + reg); 186 } 187 188 static inline void ar2315_pci_reg_mask(struct ar2315_pci_ctrl *apc, u32 reg, 189 u32 mask, u32 val) 190 { 191 u32 ret = ar2315_pci_reg_read(apc, reg); 192 193 ret &= ~mask; 194 ret |= val; 195 ar2315_pci_reg_write(apc, reg, ret); 196 } 197 198 static int ar2315_pci_cfg_access(struct ar2315_pci_ctrl *apc, unsigned devfn, 199 int where, int size, u32 *ptr, bool write) 200 { 201 int func = PCI_FUNC(devfn); 202 int dev = PCI_SLOT(devfn); 203 u32 addr = (1 << (13 + dev)) | (func << 8) | (where & ~3); 204 u32 mask = 0xffffffff >> 8 * (4 - size); 205 u32 sh = (where & 3) * 8; 206 u32 value, isr; 207 208 /* Prevent access past the remapped area */ 209 if (addr >= AR2315_PCI_CFG_SIZE || dev > 18) 210 return PCIBIOS_DEVICE_NOT_FOUND; 211 212 /* Clear pending errors */ 213 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 214 /* Select Configuration access */ 215 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 0, 216 AR2315_PCIMISC_CFG_SEL); 217 218 mb(); /* PCI must see space change before we begin */ 219 220 value = __raw_readl(apc->cfg_mem + addr); 221 222 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 223 224 if (isr & AR2315_PCI_INT_ABORT) 225 goto exit_err; 226 227 if (write) { 228 value = (value & ~(mask << sh)) | *ptr << sh; 229 __raw_writel(value, apc->cfg_mem + addr); 230 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 231 if (isr & AR2315_PCI_INT_ABORT) 232 goto exit_err; 233 } else { 234 *ptr = (value >> sh) & mask; 235 } 236 237 goto exit; 238 239 exit_err: 240 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 241 if (!write) 242 *ptr = 0xffffffff; 243 244 exit: 245 /* Select Memory access */ 246 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_CFG_SEL, 247 0); 248 249 return isr & AR2315_PCI_INT_ABORT ? PCIBIOS_DEVICE_NOT_FOUND : 250 PCIBIOS_SUCCESSFUL; 251 } 252 253 static inline int ar2315_pci_local_cfg_rd(struct ar2315_pci_ctrl *apc, 254 unsigned devfn, int where, u32 *val) 255 { 256 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), val, 257 false); 258 } 259 260 static inline int ar2315_pci_local_cfg_wr(struct ar2315_pci_ctrl *apc, 261 unsigned devfn, int where, u32 val) 262 { 263 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), &val, 264 true); 265 } 266 267 static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned devfn, int where, 268 int size, u32 *value) 269 { 270 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 271 272 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 273 return PCIBIOS_DEVICE_NOT_FOUND; 274 275 return ar2315_pci_cfg_access(apc, devfn, where, size, value, false); 276 } 277 278 static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned devfn, int where, 279 int size, u32 value) 280 { 281 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 282 283 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 284 return PCIBIOS_DEVICE_NOT_FOUND; 285 286 return ar2315_pci_cfg_access(apc, devfn, where, size, &value, true); 287 } 288 289 static struct pci_ops ar2315_pci_ops = { 290 .read = ar2315_pci_cfg_read, 291 .write = ar2315_pci_cfg_write, 292 }; 293 294 static int ar2315_pci_host_setup(struct ar2315_pci_ctrl *apc) 295 { 296 unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0); 297 int res; 298 u32 id; 299 300 res = ar2315_pci_local_cfg_rd(apc, devfn, PCI_VENDOR_ID, &id); 301 if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID) 302 return -ENODEV; 303 304 /* Program MBARs */ 305 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_0, 306 AR2315_PCI_HOST_MBAR0); 307 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_1, 308 AR2315_PCI_HOST_MBAR1); 309 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_2, 310 AR2315_PCI_HOST_MBAR2); 311 312 /* Run */ 313 ar2315_pci_local_cfg_wr(apc, devfn, PCI_COMMAND, PCI_COMMAND_MEMORY | 314 PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL | 315 PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY | 316 PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK); 317 318 return 0; 319 } 320 321 static void ar2315_pci_irq_handler(unsigned irq, struct irq_desc *desc) 322 { 323 struct ar2315_pci_ctrl *apc = irq_get_handler_data(irq); 324 u32 pending = ar2315_pci_reg_read(apc, AR2315_PCI_ISR) & 325 ar2315_pci_reg_read(apc, AR2315_PCI_IMR); 326 unsigned pci_irq = 0; 327 328 if (pending) 329 pci_irq = irq_find_mapping(apc->domain, __ffs(pending)); 330 331 if (pci_irq) 332 generic_handle_irq(pci_irq); 333 else 334 spurious_interrupt(); 335 } 336 337 static void ar2315_pci_irq_mask(struct irq_data *d) 338 { 339 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 340 341 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, BIT(d->hwirq), 0); 342 } 343 344 static void ar2315_pci_irq_mask_ack(struct irq_data *d) 345 { 346 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 347 u32 m = BIT(d->hwirq); 348 349 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, m, 0); 350 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, m); 351 } 352 353 static void ar2315_pci_irq_unmask(struct irq_data *d) 354 { 355 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 356 357 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, 0, BIT(d->hwirq)); 358 } 359 360 static struct irq_chip ar2315_pci_irq_chip = { 361 .name = "AR2315-PCI", 362 .irq_mask = ar2315_pci_irq_mask, 363 .irq_mask_ack = ar2315_pci_irq_mask_ack, 364 .irq_unmask = ar2315_pci_irq_unmask, 365 }; 366 367 static int ar2315_pci_irq_map(struct irq_domain *d, unsigned irq, 368 irq_hw_number_t hw) 369 { 370 irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, handle_level_irq); 371 irq_set_chip_data(irq, d->host_data); 372 return 0; 373 } 374 375 static struct irq_domain_ops ar2315_pci_irq_domain_ops = { 376 .map = ar2315_pci_irq_map, 377 }; 378 379 static void ar2315_pci_irq_init(struct ar2315_pci_ctrl *apc) 380 { 381 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0); 382 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT | 383 AR2315_PCI_INT_EXT), 0); 384 385 apc->irq_ext = irq_create_mapping(apc->domain, AR2315_PCI_IRQ_EXT); 386 387 irq_set_chained_handler(apc->irq, ar2315_pci_irq_handler); 388 irq_set_handler_data(apc->irq, apc); 389 390 /* Clear any pending Abort or external Interrupts 391 * and enable interrupt processing */ 392 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT | 393 AR2315_PCI_INT_EXT); 394 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE); 395 } 396 397 static int ar2315_pci_probe(struct platform_device *pdev) 398 { 399 struct ar2315_pci_ctrl *apc; 400 struct device *dev = &pdev->dev; 401 struct resource *res; 402 int irq, err; 403 404 apc = devm_kzalloc(dev, sizeof(*apc), GFP_KERNEL); 405 if (!apc) 406 return -ENOMEM; 407 408 irq = platform_get_irq(pdev, 0); 409 if (irq < 0) 410 return -EINVAL; 411 apc->irq = irq; 412 413 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, 414 "ar2315-pci-ctrl"); 415 apc->mmr_mem = devm_ioremap_resource(dev, res); 416 if (IS_ERR(apc->mmr_mem)) 417 return PTR_ERR(apc->mmr_mem); 418 419 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, 420 "ar2315-pci-ext"); 421 if (!res) 422 return -EINVAL; 423 424 apc->mem_res.name = "AR2315 PCI mem space"; 425 apc->mem_res.parent = res; 426 apc->mem_res.start = res->start; 427 apc->mem_res.end = res->end; 428 apc->mem_res.flags = IORESOURCE_MEM; 429 430 /* Remap PCI config space */ 431 apc->cfg_mem = devm_ioremap_nocache(dev, res->start, 432 AR2315_PCI_CFG_SIZE); 433 if (!apc->cfg_mem) { 434 dev_err(dev, "failed to remap PCI config space\n"); 435 return -ENOMEM; 436 } 437 438 /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */ 439 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 440 AR2315_PCIMISC_RST_MODE, 441 AR2315_PCIRST_LOW); 442 msleep(100); 443 444 /* Bring the PCI out of reset */ 445 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 446 AR2315_PCIMISC_RST_MODE, 447 AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8); 448 449 ar2315_pci_reg_write(apc, AR2315_PCI_UNCACHE_CFG, 450 0x1E | /* 1GB uncached */ 451 (1 << 5) | /* Enable uncached */ 452 (0x2 << 30) /* Base: 0x80000000 */); 453 ar2315_pci_reg_read(apc, AR2315_PCI_UNCACHE_CFG); 454 455 msleep(500); 456 457 err = ar2315_pci_host_setup(apc); 458 if (err) 459 return err; 460 461 apc->domain = irq_domain_add_linear(NULL, AR2315_PCI_IRQ_COUNT, 462 &ar2315_pci_irq_domain_ops, apc); 463 if (!apc->domain) { 464 dev_err(dev, "failed to add IRQ domain\n"); 465 return -ENOMEM; 466 } 467 468 ar2315_pci_irq_init(apc); 469 470 /* PCI controller does not support I/O ports */ 471 apc->io_res.name = "AR2315 IO space"; 472 apc->io_res.start = 0; 473 apc->io_res.end = 0; 474 apc->io_res.flags = IORESOURCE_IO, 475 476 apc->pci_ctrl.pci_ops = &ar2315_pci_ops; 477 apc->pci_ctrl.mem_resource = &apc->mem_res, 478 apc->pci_ctrl.io_resource = &apc->io_res, 479 480 register_pci_controller(&apc->pci_ctrl); 481 482 dev_info(dev, "register PCI controller\n"); 483 484 return 0; 485 } 486 487 static struct platform_driver ar2315_pci_driver = { 488 .probe = ar2315_pci_probe, 489 .driver = { 490 .name = "ar2315-pci", 491 .owner = THIS_MODULE, 492 }, 493 }; 494 495 static int __init ar2315_pci_init(void) 496 { 497 return platform_driver_register(&ar2315_pci_driver); 498 } 499 arch_initcall(ar2315_pci_init); 500 501 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) 502 { 503 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(dev->bus); 504 505 return slot ? 0 : apc->irq_ext; 506 } 507 508 int pcibios_plat_dev_init(struct pci_dev *dev) 509 { 510 return 0; 511 } 512