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/dma-direct.h> 35 #include <linux/mm.h> 36 #include <linux/delay.h> 37 #include <linux/bitops.h> 38 #include <linux/irq.h> 39 #include <linux/irqdomain.h> 40 #include <linux/io.h> 41 #include <asm/paccess.h> 42 43 /* 44 * PCI Bus Interface Registers 45 */ 46 #define AR2315_PCI_1MS_REG 0x0008 47 48 #define AR2315_PCI_1MS_MASK 0x3FFFF /* # of AHB clk cycles in 1ms */ 49 50 #define AR2315_PCI_MISC_CONFIG 0x000c 51 52 #define AR2315_PCIMISC_TXD_EN 0x00000001 /* Enable TXD for fragments */ 53 #define AR2315_PCIMISC_CFG_SEL 0x00000002 /* Mem or Config cycles */ 54 #define AR2315_PCIMISC_GIG_MASK 0x0000000C /* bits 31-30 for pci req */ 55 #define AR2315_PCIMISC_RST_MODE 0x00000030 56 #define AR2315_PCIRST_INPUT 0x00000000 /* 4:5=0 rst is input */ 57 #define AR2315_PCIRST_LOW 0x00000010 /* 4:5=1 rst to GND */ 58 #define AR2315_PCIRST_HIGH 0x00000020 /* 4:5=2 rst to VDD */ 59 #define AR2315_PCIGRANT_EN 0x00000000 /* 6:7=0 early grant en */ 60 #define AR2315_PCIGRANT_FRAME 0x00000040 /* 6:7=1 grant waits 4 frame */ 61 #define AR2315_PCIGRANT_IDLE 0x00000080 /* 6:7=2 grant waits 4 idle */ 62 #define AR2315_PCIGRANT_GAP 0x00000000 /* 6:7=2 grant waits 4 idle */ 63 #define AR2315_PCICACHE_DIS 0x00001000 /* PCI external access cache 64 * disable */ 65 66 #define AR2315_PCI_OUT_TSTAMP 0x0010 67 68 #define AR2315_PCI_UNCACHE_CFG 0x0014 69 70 #define AR2315_PCI_IN_EN 0x0100 71 72 #define AR2315_PCI_IN_EN0 0x01 /* Enable chain 0 */ 73 #define AR2315_PCI_IN_EN1 0x02 /* Enable chain 1 */ 74 #define AR2315_PCI_IN_EN2 0x04 /* Enable chain 2 */ 75 #define AR2315_PCI_IN_EN3 0x08 /* Enable chain 3 */ 76 77 #define AR2315_PCI_IN_DIS 0x0104 78 79 #define AR2315_PCI_IN_DIS0 0x01 /* Disable chain 0 */ 80 #define AR2315_PCI_IN_DIS1 0x02 /* Disable chain 1 */ 81 #define AR2315_PCI_IN_DIS2 0x04 /* Disable chain 2 */ 82 #define AR2315_PCI_IN_DIS3 0x08 /* Disable chain 3 */ 83 84 #define AR2315_PCI_IN_PTR 0x0200 85 86 #define AR2315_PCI_OUT_EN 0x0400 87 88 #define AR2315_PCI_OUT_EN0 0x01 /* Enable chain 0 */ 89 90 #define AR2315_PCI_OUT_DIS 0x0404 91 92 #define AR2315_PCI_OUT_DIS0 0x01 /* Disable chain 0 */ 93 94 #define AR2315_PCI_OUT_PTR 0x0408 95 96 /* PCI interrupt status (write one to clear) */ 97 #define AR2315_PCI_ISR 0x0500 98 99 #define AR2315_PCI_INT_TX 0x00000001 /* Desc In Completed */ 100 #define AR2315_PCI_INT_TXOK 0x00000002 /* Desc In OK */ 101 #define AR2315_PCI_INT_TXERR 0x00000004 /* Desc In ERR */ 102 #define AR2315_PCI_INT_TXEOL 0x00000008 /* Desc In End-of-List */ 103 #define AR2315_PCI_INT_RX 0x00000010 /* Desc Out Completed */ 104 #define AR2315_PCI_INT_RXOK 0x00000020 /* Desc Out OK */ 105 #define AR2315_PCI_INT_RXERR 0x00000040 /* Desc Out ERR */ 106 #define AR2315_PCI_INT_RXEOL 0x00000080 /* Desc Out EOL */ 107 #define AR2315_PCI_INT_TXOOD 0x00000200 /* Desc In Out-of-Desc */ 108 #define AR2315_PCI_INT_DESCMASK 0x0000FFFF /* Desc Mask */ 109 #define AR2315_PCI_INT_EXT 0x02000000 /* Extern PCI INTA */ 110 #define AR2315_PCI_INT_ABORT 0x04000000 /* PCI bus abort event */ 111 112 /* PCI interrupt mask */ 113 #define AR2315_PCI_IMR 0x0504 114 115 /* Global PCI interrupt enable */ 116 #define AR2315_PCI_IER 0x0508 117 118 #define AR2315_PCI_IER_DISABLE 0x00 /* disable pci interrupts */ 119 #define AR2315_PCI_IER_ENABLE 0x01 /* enable pci interrupts */ 120 121 #define AR2315_PCI_HOST_IN_EN 0x0800 122 #define AR2315_PCI_HOST_IN_DIS 0x0804 123 #define AR2315_PCI_HOST_IN_PTR 0x0810 124 #define AR2315_PCI_HOST_OUT_EN 0x0900 125 #define AR2315_PCI_HOST_OUT_DIS 0x0904 126 #define AR2315_PCI_HOST_OUT_PTR 0x0908 127 128 /* 129 * PCI interrupts, which share IP5 130 * Keep ordered according to AR2315_PCI_INT_XXX bits 131 */ 132 #define AR2315_PCI_IRQ_EXT 25 133 #define AR2315_PCI_IRQ_ABORT 26 134 #define AR2315_PCI_IRQ_COUNT 27 135 136 /* Arbitrary size of memory region to access the configuration space */ 137 #define AR2315_PCI_CFG_SIZE 0x00100000 138 139 #define AR2315_PCI_HOST_SLOT 3 140 #define AR2315_PCI_HOST_DEVID ((0xff18 << 16) | PCI_VENDOR_ID_ATHEROS) 141 142 /* 143 * We need some arbitrary non-zero value to be programmed to the BAR1 register 144 * of PCI host controller to enable DMA. The same value should be used as the 145 * offset to calculate the physical address of DMA buffer for PCI devices. 146 */ 147 #define AR2315_PCI_HOST_SDRAM_BASEADDR 0x20000000 148 149 /* ??? access BAR */ 150 #define AR2315_PCI_HOST_MBAR0 0x10000000 151 /* RAM access BAR */ 152 #define AR2315_PCI_HOST_MBAR1 AR2315_PCI_HOST_SDRAM_BASEADDR 153 /* ??? access BAR */ 154 #define AR2315_PCI_HOST_MBAR2 0x30000000 155 156 struct ar2315_pci_ctrl { 157 void __iomem *cfg_mem; 158 void __iomem *mmr_mem; 159 unsigned irq; 160 unsigned irq_ext; 161 struct irq_domain *domain; 162 struct pci_controller pci_ctrl; 163 struct resource mem_res; 164 struct resource io_res; 165 }; 166 167 static inline dma_addr_t ar2315_dev_offset(struct device *dev) 168 { 169 if (dev && dev_is_pci(dev)) 170 return AR2315_PCI_HOST_SDRAM_BASEADDR; 171 return 0; 172 } 173 174 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) 175 { 176 return paddr + ar2315_dev_offset(dev); 177 } 178 179 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) 180 { 181 return dma_addr - ar2315_dev_offset(dev); 182 } 183 184 static inline struct ar2315_pci_ctrl *ar2315_pci_bus_to_apc(struct pci_bus *bus) 185 { 186 struct pci_controller *hose = bus->sysdata; 187 188 return container_of(hose, struct ar2315_pci_ctrl, pci_ctrl); 189 } 190 191 static inline u32 ar2315_pci_reg_read(struct ar2315_pci_ctrl *apc, u32 reg) 192 { 193 return __raw_readl(apc->mmr_mem + reg); 194 } 195 196 static inline void ar2315_pci_reg_write(struct ar2315_pci_ctrl *apc, u32 reg, 197 u32 val) 198 { 199 __raw_writel(val, apc->mmr_mem + reg); 200 } 201 202 static inline void ar2315_pci_reg_mask(struct ar2315_pci_ctrl *apc, u32 reg, 203 u32 mask, u32 val) 204 { 205 u32 ret = ar2315_pci_reg_read(apc, reg); 206 207 ret &= ~mask; 208 ret |= val; 209 ar2315_pci_reg_write(apc, reg, ret); 210 } 211 212 static int ar2315_pci_cfg_access(struct ar2315_pci_ctrl *apc, unsigned devfn, 213 int where, int size, u32 *ptr, bool write) 214 { 215 int func = PCI_FUNC(devfn); 216 int dev = PCI_SLOT(devfn); 217 u32 addr = (1 << (13 + dev)) | (func << 8) | (where & ~3); 218 u32 mask = 0xffffffff >> 8 * (4 - size); 219 u32 sh = (where & 3) * 8; 220 u32 value, isr; 221 222 /* Prevent access past the remapped area */ 223 if (addr >= AR2315_PCI_CFG_SIZE || dev > 18) 224 return PCIBIOS_DEVICE_NOT_FOUND; 225 226 /* Clear pending errors */ 227 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 228 /* Select Configuration access */ 229 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 0, 230 AR2315_PCIMISC_CFG_SEL); 231 232 mb(); /* PCI must see space change before we begin */ 233 234 value = __raw_readl(apc->cfg_mem + addr); 235 236 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 237 238 if (isr & AR2315_PCI_INT_ABORT) 239 goto exit_err; 240 241 if (write) { 242 value = (value & ~(mask << sh)) | *ptr << sh; 243 __raw_writel(value, apc->cfg_mem + addr); 244 isr = ar2315_pci_reg_read(apc, AR2315_PCI_ISR); 245 if (isr & AR2315_PCI_INT_ABORT) 246 goto exit_err; 247 } else { 248 *ptr = (value >> sh) & mask; 249 } 250 251 goto exit; 252 253 exit_err: 254 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT); 255 if (!write) 256 *ptr = 0xffffffff; 257 258 exit: 259 /* Select Memory access */ 260 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, AR2315_PCIMISC_CFG_SEL, 261 0); 262 263 return isr & AR2315_PCI_INT_ABORT ? PCIBIOS_DEVICE_NOT_FOUND : 264 PCIBIOS_SUCCESSFUL; 265 } 266 267 static inline int ar2315_pci_local_cfg_rd(struct ar2315_pci_ctrl *apc, 268 unsigned devfn, int where, u32 *val) 269 { 270 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), val, 271 false); 272 } 273 274 static inline int ar2315_pci_local_cfg_wr(struct ar2315_pci_ctrl *apc, 275 unsigned devfn, int where, u32 val) 276 { 277 return ar2315_pci_cfg_access(apc, devfn, where, sizeof(u32), &val, 278 true); 279 } 280 281 static int ar2315_pci_cfg_read(struct pci_bus *bus, unsigned devfn, int where, 282 int size, u32 *value) 283 { 284 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 285 286 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 287 return PCIBIOS_DEVICE_NOT_FOUND; 288 289 return ar2315_pci_cfg_access(apc, devfn, where, size, value, false); 290 } 291 292 static int ar2315_pci_cfg_write(struct pci_bus *bus, unsigned devfn, int where, 293 int size, u32 value) 294 { 295 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(bus); 296 297 if (PCI_SLOT(devfn) == AR2315_PCI_HOST_SLOT) 298 return PCIBIOS_DEVICE_NOT_FOUND; 299 300 return ar2315_pci_cfg_access(apc, devfn, where, size, &value, true); 301 } 302 303 static struct pci_ops ar2315_pci_ops = { 304 .read = ar2315_pci_cfg_read, 305 .write = ar2315_pci_cfg_write, 306 }; 307 308 static int ar2315_pci_host_setup(struct ar2315_pci_ctrl *apc) 309 { 310 unsigned devfn = PCI_DEVFN(AR2315_PCI_HOST_SLOT, 0); 311 int res; 312 u32 id; 313 314 res = ar2315_pci_local_cfg_rd(apc, devfn, PCI_VENDOR_ID, &id); 315 if (res != PCIBIOS_SUCCESSFUL || id != AR2315_PCI_HOST_DEVID) 316 return -ENODEV; 317 318 /* Program MBARs */ 319 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_0, 320 AR2315_PCI_HOST_MBAR0); 321 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_1, 322 AR2315_PCI_HOST_MBAR1); 323 ar2315_pci_local_cfg_wr(apc, devfn, PCI_BASE_ADDRESS_2, 324 AR2315_PCI_HOST_MBAR2); 325 326 /* Run */ 327 ar2315_pci_local_cfg_wr(apc, devfn, PCI_COMMAND, PCI_COMMAND_MEMORY | 328 PCI_COMMAND_MASTER | PCI_COMMAND_SPECIAL | 329 PCI_COMMAND_INVALIDATE | PCI_COMMAND_PARITY | 330 PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK); 331 332 return 0; 333 } 334 335 static void ar2315_pci_irq_handler(struct irq_desc *desc) 336 { 337 struct ar2315_pci_ctrl *apc = irq_desc_get_handler_data(desc); 338 u32 pending = ar2315_pci_reg_read(apc, AR2315_PCI_ISR) & 339 ar2315_pci_reg_read(apc, AR2315_PCI_IMR); 340 unsigned pci_irq = 0; 341 342 if (pending) 343 pci_irq = irq_find_mapping(apc->domain, __ffs(pending)); 344 345 if (pci_irq) 346 generic_handle_irq(pci_irq); 347 else 348 spurious_interrupt(); 349 } 350 351 static void ar2315_pci_irq_mask(struct irq_data *d) 352 { 353 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 354 355 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, BIT(d->hwirq), 0); 356 } 357 358 static void ar2315_pci_irq_mask_ack(struct irq_data *d) 359 { 360 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 361 u32 m = BIT(d->hwirq); 362 363 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, m, 0); 364 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, m); 365 } 366 367 static void ar2315_pci_irq_unmask(struct irq_data *d) 368 { 369 struct ar2315_pci_ctrl *apc = irq_data_get_irq_chip_data(d); 370 371 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, 0, BIT(d->hwirq)); 372 } 373 374 static struct irq_chip ar2315_pci_irq_chip = { 375 .name = "AR2315-PCI", 376 .irq_mask = ar2315_pci_irq_mask, 377 .irq_mask_ack = ar2315_pci_irq_mask_ack, 378 .irq_unmask = ar2315_pci_irq_unmask, 379 }; 380 381 static int ar2315_pci_irq_map(struct irq_domain *d, unsigned irq, 382 irq_hw_number_t hw) 383 { 384 irq_set_chip_and_handler(irq, &ar2315_pci_irq_chip, handle_level_irq); 385 irq_set_chip_data(irq, d->host_data); 386 return 0; 387 } 388 389 static struct irq_domain_ops ar2315_pci_irq_domain_ops = { 390 .map = ar2315_pci_irq_map, 391 }; 392 393 static void ar2315_pci_irq_init(struct ar2315_pci_ctrl *apc) 394 { 395 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, AR2315_PCI_IER_ENABLE, 0); 396 ar2315_pci_reg_mask(apc, AR2315_PCI_IMR, (AR2315_PCI_INT_ABORT | 397 AR2315_PCI_INT_EXT), 0); 398 399 apc->irq_ext = irq_create_mapping(apc->domain, AR2315_PCI_IRQ_EXT); 400 401 irq_set_chained_handler_and_data(apc->irq, ar2315_pci_irq_handler, 402 apc); 403 404 /* Clear any pending Abort or external Interrupts 405 * and enable interrupt processing */ 406 ar2315_pci_reg_write(apc, AR2315_PCI_ISR, AR2315_PCI_INT_ABORT | 407 AR2315_PCI_INT_EXT); 408 ar2315_pci_reg_mask(apc, AR2315_PCI_IER, 0, AR2315_PCI_IER_ENABLE); 409 } 410 411 static int ar2315_pci_probe(struct platform_device *pdev) 412 { 413 struct ar2315_pci_ctrl *apc; 414 struct device *dev = &pdev->dev; 415 struct resource *res; 416 int irq, err; 417 418 apc = devm_kzalloc(dev, sizeof(*apc), GFP_KERNEL); 419 if (!apc) 420 return -ENOMEM; 421 422 irq = platform_get_irq(pdev, 0); 423 if (irq < 0) 424 return -EINVAL; 425 apc->irq = irq; 426 427 apc->mmr_mem = devm_platform_ioremap_resource_byname(pdev, 428 "ar2315-pci-ctrl"); 429 if (IS_ERR(apc->mmr_mem)) 430 return PTR_ERR(apc->mmr_mem); 431 432 res = platform_get_resource_byname(pdev, IORESOURCE_MEM, 433 "ar2315-pci-ext"); 434 if (!res) 435 return -EINVAL; 436 437 apc->mem_res.name = "AR2315 PCI mem space"; 438 apc->mem_res.parent = res; 439 apc->mem_res.start = res->start; 440 apc->mem_res.end = res->end; 441 apc->mem_res.flags = IORESOURCE_MEM; 442 443 /* Remap PCI config space */ 444 apc->cfg_mem = devm_ioremap(dev, res->start, 445 AR2315_PCI_CFG_SIZE); 446 if (!apc->cfg_mem) { 447 dev_err(dev, "failed to remap PCI config space\n"); 448 return -ENOMEM; 449 } 450 451 /* Reset the PCI bus by setting bits 5-4 in PCI_MCFG */ 452 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 453 AR2315_PCIMISC_RST_MODE, 454 AR2315_PCIRST_LOW); 455 msleep(100); 456 457 /* Bring the PCI out of reset */ 458 ar2315_pci_reg_mask(apc, AR2315_PCI_MISC_CONFIG, 459 AR2315_PCIMISC_RST_MODE, 460 AR2315_PCIRST_HIGH | AR2315_PCICACHE_DIS | 0x8); 461 462 ar2315_pci_reg_write(apc, AR2315_PCI_UNCACHE_CFG, 463 0x1E | /* 1GB uncached */ 464 (1 << 5) | /* Enable uncached */ 465 (0x2 << 30) /* Base: 0x80000000 */); 466 ar2315_pci_reg_read(apc, AR2315_PCI_UNCACHE_CFG); 467 468 msleep(500); 469 470 err = ar2315_pci_host_setup(apc); 471 if (err) 472 return err; 473 474 apc->domain = irq_domain_add_linear(NULL, AR2315_PCI_IRQ_COUNT, 475 &ar2315_pci_irq_domain_ops, apc); 476 if (!apc->domain) { 477 dev_err(dev, "failed to add IRQ domain\n"); 478 return -ENOMEM; 479 } 480 481 ar2315_pci_irq_init(apc); 482 483 /* PCI controller does not support I/O ports */ 484 apc->io_res.name = "AR2315 IO space"; 485 apc->io_res.start = 0; 486 apc->io_res.end = 0; 487 apc->io_res.flags = IORESOURCE_IO; 488 489 apc->pci_ctrl.pci_ops = &ar2315_pci_ops; 490 apc->pci_ctrl.mem_resource = &apc->mem_res; 491 apc->pci_ctrl.io_resource = &apc->io_res; 492 493 register_pci_controller(&apc->pci_ctrl); 494 495 dev_info(dev, "register PCI controller\n"); 496 497 return 0; 498 } 499 500 static struct platform_driver ar2315_pci_driver = { 501 .probe = ar2315_pci_probe, 502 .driver = { 503 .name = "ar2315-pci", 504 }, 505 }; 506 507 static int __init ar2315_pci_init(void) 508 { 509 return platform_driver_register(&ar2315_pci_driver); 510 } 511 arch_initcall(ar2315_pci_init); 512 513 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) 514 { 515 struct ar2315_pci_ctrl *apc = ar2315_pci_bus_to_apc(dev->bus); 516 517 return slot ? 0 : apc->irq_ext; 518 } 519 520 int pcibios_plat_dev_init(struct pci_dev *dev) 521 { 522 return 0; 523 } 524