1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 */ 4 5 /** 6 * Both AR2315 and AR2316 chips have PCI interface unit, which supports DMA 7 * and interrupt. PCI interface supports MMIO access method, but does not 8 * seem to support I/O ports. 9 * 10 * Read/write operation in the region 0x80000000-0xBFFFFFFF causes 11 * a memory read/write command on the PCI bus. 30 LSBs of address on 12 * the bus are taken from memory read/write request and 2 MSBs are 13 * determined by PCI unit configuration. 14 * 15 * To work with the configuration space instead of memory is necessary set 16 * the CFG_SEL bit in the PCI_MISC_CONFIG register. 17 * 18 * Devices on the bus can perform DMA requests via chip BAR1. PCI host 19 * controller BARs are programmend as if an external device is programmed. 20 * Which means that during configuration, IDSEL pin of the chip should be 21 * asserted. 22 * 23 * We know (and support) only one board that uses the PCI interface - 24 * Fonera 2.0g (FON2202). It has a USB EHCI controller connected to the 25 * AR2315 PCI bus. IDSEL pin of USB controller is connected to AD[13] line 26 * and IDSEL pin of AR2315 is connected to AD[16] line. 27 */ 28 29 #include <linux/types.h> 30 #include <linux/pci.h> 31 #include <linux/platform_device.h> 32 #include <linux/kernel.h> 33 #include <linux/init.h> 34 #include <linux/mm.h> 35 #include <linux/delay.h> 36 #include <linux/bitops.h> 37 #include <linux/irq.h> 38 #include <linux/irqdomain.h> 39 #include <linux/io.h> 40 #include <asm/paccess.h> 41 42 /* 43 * PCI Bus Interface Registers 44 */ 45 #define AR2315_PCI_1MS_REG 0x0008 46 47 #define AR2315_PCI_1MS_MASK 0x3FFFF /* # of AHB clk cycles in 1ms */ 48 49 #define AR2315_PCI_MISC_CONFIG 0x000c 50 51 #define AR2315_PCIMISC_TXD_EN 0x00000001 /* Enable TXD for fragments */ 52 #define AR2315_PCIMISC_CFG_SEL 0x00000002 /* Mem or Config cycles */ 53 #define AR2315_PCIMISC_GIG_MASK 0x0000000C /* bits 31-30 for pci req */ 54 #define AR2315_PCIMISC_RST_MODE 0x00000030 55 #define AR2315_PCIRST_INPUT 0x00000000 /* 4:5=0 rst is input */ 56 #define AR2315_PCIRST_LOW 0x00000010 /* 4:5=1 rst to GND */ 57 #define AR2315_PCIRST_HIGH 0x00000020 /* 4:5=2 rst to VDD */ 58 #define AR2315_PCIGRANT_EN 0x00000000 /* 6:7=0 early grant en */ 59 #define AR2315_PCIGRANT_FRAME 0x00000040 /* 6:7=1 grant waits 4 frame */ 60 #define AR2315_PCIGRANT_IDLE 0x00000080 /* 6:7=2 grant waits 4 idle */ 61 #define AR2315_PCIGRANT_GAP 0x00000000 /* 6:7=2 grant waits 4 idle */ 62 #define AR2315_PCICACHE_DIS 0x00001000 /* PCI external access cache 63 * disable */ 64 65 #define AR2315_PCI_OUT_TSTAMP 0x0010 66 67 #define AR2315_PCI_UNCACHE_CFG 0x0014 68 69 #define AR2315_PCI_IN_EN 0x0100 70 71 #define AR2315_PCI_IN_EN0 0x01 /* Enable chain 0 */ 72 #define AR2315_PCI_IN_EN1 0x02 /* Enable chain 1 */ 73 #define AR2315_PCI_IN_EN2 0x04 /* Enable chain 2 */ 74 #define AR2315_PCI_IN_EN3 0x08 /* Enable chain 3 */ 75 76 #define AR2315_PCI_IN_DIS 0x0104 77 78 #define AR2315_PCI_IN_DIS0 0x01 /* Disable chain 0 */ 79 #define AR2315_PCI_IN_DIS1 0x02 /* Disable chain 1 */ 80 #define AR2315_PCI_IN_DIS2 0x04 /* Disable chain 2 */ 81 #define AR2315_PCI_IN_DIS3 0x08 /* Disable chain 3 */ 82 83 #define AR2315_PCI_IN_PTR 0x0200 84 85 #define AR2315_PCI_OUT_EN 0x0400 86 87 #define AR2315_PCI_OUT_EN0 0x01 /* Enable chain 0 */ 88 89 #define AR2315_PCI_OUT_DIS 0x0404 90 91 #define AR2315_PCI_OUT_DIS0 0x01 /* Disable chain 0 */ 92 93 #define AR2315_PCI_OUT_PTR 0x0408 94 95 /* PCI interrupt status (write one to clear) */ 96 #define AR2315_PCI_ISR 0x0500 97 98 #define AR2315_PCI_INT_TX 0x00000001 /* Desc In Completed */ 99 #define AR2315_PCI_INT_TXOK 0x00000002 /* Desc In OK */ 100 #define AR2315_PCI_INT_TXERR 0x00000004 /* Desc In ERR */ 101 #define AR2315_PCI_INT_TXEOL 0x00000008 /* Desc In End-of-List */ 102 #define AR2315_PCI_INT_RX 0x00000010 /* Desc Out Completed */ 103 #define AR2315_PCI_INT_RXOK 0x00000020 /* Desc Out OK */ 104 #define AR2315_PCI_INT_RXERR 0x00000040 /* Desc Out ERR */ 105 #define AR2315_PCI_INT_RXEOL 0x00000080 /* Desc Out EOL */ 106 #define AR2315_PCI_INT_TXOOD 0x00000200 /* Desc In Out-of-Desc */ 107 #define AR2315_PCI_INT_DESCMASK 0x0000FFFF /* Desc Mask */ 108 #define AR2315_PCI_INT_EXT 0x02000000 /* Extern PCI INTA */ 109 #define AR2315_PCI_INT_ABORT 0x04000000 /* PCI bus abort event */ 110 111 /* PCI interrupt mask */ 112 #define AR2315_PCI_IMR 0x0504 113 114 /* Global PCI interrupt enable */ 115 #define AR2315_PCI_IER 0x0508 116 117 #define AR2315_PCI_IER_DISABLE 0x00 /* disable pci interrupts */ 118 #define AR2315_PCI_IER_ENABLE 0x01 /* enable pci interrupts */ 119 120 #define AR2315_PCI_HOST_IN_EN 0x0800 121 #define AR2315_PCI_HOST_IN_DIS 0x0804 122 #define AR2315_PCI_HOST_IN_PTR 0x0810 123 #define AR2315_PCI_HOST_OUT_EN 0x0900 124 #define AR2315_PCI_HOST_OUT_DIS 0x0904 125 #define AR2315_PCI_HOST_OUT_PTR 0x0908 126 127 /* 128 * PCI interrupts, which share IP5 129 * Keep ordered according to AR2315_PCI_INT_XXX bits 130 */ 131 #define AR2315_PCI_IRQ_EXT 25 132 #define AR2315_PCI_IRQ_ABORT 26 133 #define AR2315_PCI_IRQ_COUNT 27 134 135 /* Arbitrary size of memory region to access the configuration space */ 136 #define AR2315_PCI_CFG_SIZE 0x00100000 137 138 #define AR2315_PCI_HOST_SLOT 3 139 #define AR2315_PCI_HOST_DEVID ((0xff18 << 16) | PCI_VENDOR_ID_ATHEROS) 140 141 /* 142 * We need some arbitrary non-zero value to be programmed to the BAR1 register 143 * of PCI host controller to enable DMA. The same value should be used as the 144 * offset to calculate the physical address of DMA buffer for PCI devices. 145 */ 146 #define AR2315_PCI_HOST_SDRAM_BASEADDR 0x20000000 147 148 /* ??? access BAR */ 149 #define AR2315_PCI_HOST_MBAR0 0x10000000 150 /* RAM access BAR */ 151 #define AR2315_PCI_HOST_MBAR1 AR2315_PCI_HOST_SDRAM_BASEADDR 152 /* ??? access BAR */ 153 #define AR2315_PCI_HOST_MBAR2 0x30000000 154 155 struct ar2315_pci_ctrl { 156 void __iomem *cfg_mem; 157 void __iomem *mmr_mem; 158 unsigned irq; 159 unsigned irq_ext; 160 struct irq_domain *domain; 161 struct pci_controller pci_ctrl; 162 struct resource mem_res; 163 struct resource io_res; 164 }; 165 166 static inline dma_addr_t ar2315_dev_offset(struct device *dev) 167 { 168 if (dev && dev_is_pci(dev)) 169 return AR2315_PCI_HOST_SDRAM_BASEADDR; 170 return 0; 171 } 172 173 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) 174 { 175 return paddr + ar2315_dev_offset(dev); 176 } 177 178 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) 179 { 180 return dma_addr - ar2315_dev_offset(dev); 181 } 182 183 static inline struct ar2315_pci_ctrl *ar2315_pci_bus_to_apc(struct pci_bus *bus) 184 { 185 struct pci_controller *hose = bus->sysdata; 186 187 return container_of(hose, struct ar2315_pci_ctrl, pci_ctrl); 188 } 189 190 static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg) 191 { 192 return __raw_readl(apc->mmr_mem + reg); 193 } 194 195 static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg, 196 u32 val) 197 { 198 __raw_writel(val, apc->mmr_mem + reg); 199 } 200 201 static inline void ar2315_pci_reg_mask(struct ar2315_pci_ctrl *apc, u32 reg, 202 u32 mask, u32 val) 203 { 204 u32 ret = ar2315_pci_reg_read(apc, reg); 205 206 ret &= ~mask; 207 ret |= val; 208 ar2315_pci_reg_write(apc, reg, ret); 209 } 210 211 static int ar2315_pci_cfg_access(struct ar2315_pci_ctrl *apc, unsigned devfn, 212 int where, int size, u32 *ptr, bool write) 213 { 214 int func = PCI_FUNC(devfn); 215 int dev = PCI_SLOT(devfn); 216 u32 addr = (1 << (13 + dev)) | (func << 8) | (where & ~3); 217 u32 mask = 0xffffffff >> 8 * (4 - size); 218 u32 sh = (where & 3) * 8; 219 u32 value, isr; 220 221 /* Prevent access past the remapped area */ 222 if (addr >= AR2315_PCI_CFG_SIZE || dev > 18) 223 return PCIBIOS_DEVICE_NOT_FOUND; 224 225 /* Clear pending errors */ 226 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 227 /* Select Configuration access */ 228 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 0, 229 AR2315_PCIMISC_CFG_SEL); 230 231 mb(); /* PCI must see space change before we begin */ 232 233 value = __raw_readl(apc->cfg_mem + addr); 234 235 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 236 237 if (isr & AR2315_PCI_INT_ABORT) 238 goto exit_err; 239 240 if (write) { 241 value = (value & ~(mask << sh)) | *ptr << sh; 242 __raw_writel(value, apc->cfg_mem + addr); 243 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 244 if (isr & AR2315_PCI_INT_ABORT) 245 goto exit_err; 246 } else { 247 *ptr = (value >> sh) & mask; 248 } 249 250 goto exit; 251 252 exit_err: 253 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 254 if (!write) 255 *ptr = 0xffffffff; 256 257 exit: 258 /* Select Memory access */ 259 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_CFG_SEL, 260 0); 261 262 return isr & AR2315_PCI_INT_ABORT ? PCIBIOS_DEVICE_NOT_FOUND : 263 PCIBIOS_SUCCESSFUL; 264 } 265 266 static inline int ar2315_pci_local_cfg_rd(struct ar2315_pci_ctrl *apc, 267 unsigned devfn, int where, u32 *val) 268 { 269 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), val, 270 false); 271 } 272 273 static inline int ar2315_pci_local_cfg_wr(struct ar2315_pci_ctrl *apc, 274 unsigned devfn, int where, u32 val) 275 { 276 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), &val, 277 true); 278 } 279 280 static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned devfn, int where, 281 int size, u32 *value) 282 { 283 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 284 285 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 286 return PCIBIOS_DEVICE_NOT_FOUND; 287 288 return ar2315_pci_cfg_access(apc, devfn, where, size, value, false); 289 } 290 291 static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned devfn, int where, 292 int size, u32 value) 293 { 294 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 295 296 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 297 return PCIBIOS_DEVICE_NOT_FOUND; 298 299 return ar2315_pci_cfg_access(apc, devfn, where, size, &value, true); 300 } 301 302 static struct pci_ops ar2315_pci_ops = { 303 .read = ar2315_pci_cfg_read, 304 .write = ar2315_pci_cfg_write, 305 }; 306 307 static int ar2315_pci_host_setup(struct ar2315_pci_ctrl *apc) 308 { 309 unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0); 310 int res; 311 u32 id; 312 313 res = ar2315_pci_local_cfg_rd(apc, devfn, PCI_VENDOR_ID, &id); 314 if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID) 315 return -ENODEV; 316 317 /* Program MBARs */ 318 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_0, 319 AR2315_PCI_HOST_MBAR0); 320 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_1, 321 AR2315_PCI_HOST_MBAR1); 322 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_2, 323 AR2315_PCI_HOST_MBAR2); 324 325 /* Run */ 326 ar2315_pci_local_cfg_wr(apc, devfn, PCI_COMMAND, PCI_COMMAND_MEMORY | 327 PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL | 328 PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY | 329 PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK); 330 331 return 0; 332 } 333 334 static void ar2315_pci_irq_handler(struct irq_desc *desc) 335 { 336 struct ar2315_pci_ctrl *apc = irq_desc_get_handler_data(desc); 337 u32 pending = ar2315_pci_reg_read(apc, AR2315_PCI_ISR) & 338 ar2315_pci_reg_read(apc, AR2315_PCI_IMR); 339 unsigned pci_irq = 0; 340 341 if (pending) 342 pci_irq = irq_find_mapping(apc->domain, __ffs(pending)); 343 344 if (pci_irq) 345 generic_handle_irq(pci_irq); 346 else 347 spurious_interrupt(); 348 } 349 350 static void ar2315_pci_irq_mask(struct irq_data *d) 351 { 352 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 353 354 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, BIT(d->hwirq), 0); 355 } 356 357 static void ar2315_pci_irq_mask_ack(struct irq_data *d) 358 { 359 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 360 u32 m = BIT(d->hwirq); 361 362 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, m, 0); 363 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, m); 364 } 365 366 static void ar2315_pci_irq_unmask(struct irq_data *d) 367 { 368 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 369 370 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, 0, BIT(d->hwirq)); 371 } 372 373 static struct irq_chip ar2315_pci_irq_chip = { 374 .name = "AR2315-PCI", 375 .irq_mask = ar2315_pci_irq_mask, 376 .irq_mask_ack = ar2315_pci_irq_mask_ack, 377 .irq_unmask = ar2315_pci_irq_unmask, 378 }; 379 380 static int ar2315_pci_irq_map(struct irq_domain *d, unsigned irq, 381 irq_hw_number_t hw) 382 { 383 irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, handle_level_irq); 384 irq_set_chip_data(irq, d->host_data); 385 return 0; 386 } 387 388 static struct irq_domain_ops ar2315_pci_irq_domain_ops = { 389 .map = ar2315_pci_irq_map, 390 }; 391 392 static void ar2315_pci_irq_init(struct ar2315_pci_ctrl *apc) 393 { 394 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0); 395 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT | 396 AR2315_PCI_INT_EXT), 0); 397 398 apc->irq_ext = irq_create_mapping(apc->domain, AR2315_PCI_IRQ_EXT); 399 400 irq_set_chained_handler_and_data(apc->irq, ar2315_pci_irq_handler, 401 apc); 402 403 /* Clear any pending Abort or external Interrupts 404 * and enable interrupt processing */ 405 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT | 406 AR2315_PCI_INT_EXT); 407 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE); 408 } 409 410 static int ar2315_pci_probe(struct platform_device *pdev) 411 { 412 struct ar2315_pci_ctrl *apc; 413 struct device *dev = &pdev->dev; 414 struct resource *res; 415 int irq, err; 416 417 apc = devm_kzalloc(dev, sizeof(*apc), GFP_KERNEL); 418 if (!apc) 419 return -ENOMEM; 420 421 irq = platform_get_irq(pdev, 0); 422 if (irq < 0) 423 return -EINVAL; 424 apc->irq = irq; 425 426 apc->mmr_mem = devm_platform_ioremap_resource_byname(pdev, 427 "ar2315-pci-ctrl"); 428 if (IS_ERR(apc->mmr_mem)) 429 return PTR_ERR(apc->mmr_mem); 430 431 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, 432 "ar2315-pci-ext"); 433 if (!res) 434 return -EINVAL; 435 436 apc->mem_res.name = "AR2315 PCI mem space"; 437 apc->mem_res.parent = res; 438 apc->mem_res.start = res->start; 439 apc->mem_res.end = res->end; 440 apc->mem_res.flags = IORESOURCE_MEM; 441 442 /* Remap PCI config space */ 443 apc->cfg_mem = devm_ioremap(dev, res->start, 444 AR2315_PCI_CFG_SIZE); 445 if (!apc->cfg_mem) { 446 dev_err(dev, "failed to remap PCI config space\n"); 447 return -ENOMEM; 448 } 449 450 /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */ 451 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 452 AR2315_PCIMISC_RST_MODE, 453 AR2315_PCIRST_LOW); 454 msleep(100); 455 456 /* Bring the PCI out of reset */ 457 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 458 AR2315_PCIMISC_RST_MODE, 459 AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8); 460 461 ar2315_pci_reg_write(apc, AR2315_PCI_UNCACHE_CFG, 462 0x1E | /* 1GB uncached */ 463 (1 << 5) | /* Enable uncached */ 464 (0x2 << 30) /* Base: 0x80000000 */); 465 ar2315_pci_reg_read(apc, AR2315_PCI_UNCACHE_CFG); 466 467 msleep(500); 468 469 err = ar2315_pci_host_setup(apc); 470 if (err) 471 return err; 472 473 apc->domain = irq_domain_add_linear(NULL, AR2315_PCI_IRQ_COUNT, 474 &ar2315_pci_irq_domain_ops, apc); 475 if (!apc->domain) { 476 dev_err(dev, "failed to add IRQ domain\n"); 477 return -ENOMEM; 478 } 479 480 ar2315_pci_irq_init(apc); 481 482 /* PCI controller does not support I/O ports */ 483 apc->io_res.name = "AR2315 IO space"; 484 apc->io_res.start = 0; 485 apc->io_res.end = 0; 486 apc->io_res.flags = IORESOURCE_IO, 487 488 apc->pci_ctrl.pci_ops = &ar2315_pci_ops; 489 apc->pci_ctrl.mem_resource = &apc->mem_res, 490 apc->pci_ctrl.io_resource = &apc->io_res, 491 492 register_pci_controller(&apc->pci_ctrl); 493 494 dev_info(dev, "register PCI controller\n"); 495 496 return 0; 497 } 498 499 static struct platform_driver ar2315_pci_driver = { 500 .probe = ar2315_pci_probe, 501 .driver = { 502 .name = "ar2315-pci", 503 }, 504 }; 505 506 static int __init ar2315_pci_init(void) 507 { 508 return platform_driver_register(&ar2315_pci_driver); 509 } 510 arch_initcall(ar2315_pci_init); 511 512 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) 513 { 514 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(dev->bus); 515 516 return slot ? 0 : apc->irq_ext; 517 } 518 519 int pcibios_plat_dev_init(struct pci_dev *dev) 520 { 521 return 0; 522 } 523