linux/drivers/pci/controller/pcie-rcar-ep.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * PCIe endpoint driver for Renesas R-Car SoCs
   4 *  Copyright (c) 2020 Renesas Electronics Europe GmbH
   5 *
   6 * Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
   7 */
   8
   9#include <linux/delay.h>
  10#include <linux/of_address.h>
  11#include <linux/of_platform.h>
  12#include <linux/pci.h>
  13#include <linux/pci-epc.h>
  14#include <linux/platform_device.h>
  15#include <linux/pm_runtime.h>
  16
  17#include "pcie-rcar.h"
  18
  19#define RCAR_EPC_MAX_FUNCTIONS          1
  20
  21/* Structure representing the PCIe interface */
  22struct rcar_pcie_endpoint {
  23        struct rcar_pcie        pcie;
  24        phys_addr_t             *ob_mapped_addr;
  25        struct pci_epc_mem_window *ob_window;
  26        u8                      max_functions;
  27        unsigned int            bar_to_atu[MAX_NR_INBOUND_MAPS];
  28        unsigned long           *ib_window_map;
  29        u32                     num_ib_windows;
  30        u32                     num_ob_windows;
  31};
  32
  33static void rcar_pcie_ep_hw_init(struct rcar_pcie *pcie)
  34{
  35        u32 val;
  36
  37        rcar_pci_write_reg(pcie, 0, PCIETCTLR);
  38
  39        /* Set endpoint mode */
  40        rcar_pci_write_reg(pcie, 0, PCIEMSR);
  41
  42        /* Initialize default capabilities. */
  43        rcar_rmw32(pcie, REXPCAP(0), 0xff, PCI_CAP_ID_EXP);
  44        rcar_rmw32(pcie, REXPCAP(PCI_EXP_FLAGS),
  45                   PCI_EXP_FLAGS_TYPE, PCI_EXP_TYPE_ENDPOINT << 4);
  46        rcar_rmw32(pcie, RCONF(PCI_HEADER_TYPE), 0x7f,
  47                   PCI_HEADER_TYPE_NORMAL);
  48
  49        /* Write out the physical slot number = 0 */
  50        rcar_rmw32(pcie, REXPCAP(PCI_EXP_SLTCAP), PCI_EXP_SLTCAP_PSN, 0);
  51
  52        val = rcar_pci_read_reg(pcie, EXPCAP(1));
  53        /* device supports fixed 128 bytes MPSS */
  54        val &= ~GENMASK(2, 0);
  55        rcar_pci_write_reg(pcie, val, EXPCAP(1));
  56
  57        val = rcar_pci_read_reg(pcie, EXPCAP(2));
  58        /* read requests size 128 bytes */
  59        val &= ~GENMASK(14, 12);
  60        /* payload size 128 bytes */
  61        val &= ~GENMASK(7, 5);
  62        rcar_pci_write_reg(pcie, val, EXPCAP(2));
  63
  64        /* Set target link speed to 5.0 GT/s */
  65        rcar_rmw32(pcie, EXPCAP(12), PCI_EXP_LNKSTA_CLS,
  66                   PCI_EXP_LNKSTA_CLS_5_0GB);
  67
  68        /* Set the completion timer timeout to the maximum 50ms. */
  69        rcar_rmw32(pcie, TLCTLR + 1, 0x3f, 50);
  70
  71        /* Terminate list of capabilities (Next Capability Offset=0) */
  72        rcar_rmw32(pcie, RVCCAP(0), 0xfff00000, 0);
  73
  74        /* flush modifications */
  75        wmb();
  76}
  77
  78static int rcar_pcie_ep_get_window(struct rcar_pcie_endpoint *ep,
  79                                   phys_addr_t addr)
  80{
  81        int i;
  82
  83        for (i = 0; i < ep->num_ob_windows; i++)
  84                if (ep->ob_window[i].phys_base == addr)
  85                        return i;
  86
  87        return -EINVAL;
  88}
  89
  90static int rcar_pcie_parse_outbound_ranges(struct rcar_pcie_endpoint *ep,
  91                                           struct platform_device *pdev)
  92{
  93        struct rcar_pcie *pcie = &ep->pcie;
  94        char outbound_name[10];
  95        struct resource *res;
  96        unsigned int i = 0;
  97
  98        ep->num_ob_windows = 0;
  99        for (i = 0; i < RCAR_PCI_MAX_RESOURCES; i++) {
 100                sprintf(outbound_name, "memory%u", i);
 101                res = platform_get_resource_byname(pdev,
 102                                                   IORESOURCE_MEM,
 103                                                   outbound_name);
 104                if (!res) {
 105                        dev_err(pcie->dev, "missing outbound window %u\n", i);
 106                        return -EINVAL;
 107                }
 108                if (!devm_request_mem_region(&pdev->dev, res->start,
 109                                             resource_size(res),
 110                                             outbound_name)) {
 111                        dev_err(pcie->dev, "Cannot request memory region %s.\n",
 112                                outbound_name);
 113                        return -EIO;
 114                }
 115
 116                ep->ob_window[i].phys_base = res->start;
 117                ep->ob_window[i].size = resource_size(res);
 118                /* controller doesn't support multiple allocation
 119                 * from same window, so set page_size to window size
 120                 */
 121                ep->ob_window[i].page_size = resource_size(res);
 122        }
 123        ep->num_ob_windows = i;
 124
 125        return 0;
 126}
 127
 128static int rcar_pcie_ep_get_pdata(struct rcar_pcie_endpoint *ep,
 129                                  struct platform_device *pdev)
 130{
 131        struct rcar_pcie *pcie = &ep->pcie;
 132        struct pci_epc_mem_window *window;
 133        struct device *dev = pcie->dev;
 134        struct resource res;
 135        int err;
 136
 137        err = of_address_to_resource(dev->of_node, 0, &res);
 138        if (err)
 139                return err;
 140        pcie->base = devm_ioremap_resource(dev, &res);
 141        if (IS_ERR(pcie->base))
 142                return PTR_ERR(pcie->base);
 143
 144        ep->ob_window = devm_kcalloc(dev, RCAR_PCI_MAX_RESOURCES,
 145                                     sizeof(*window), GFP_KERNEL);
 146        if (!ep->ob_window)
 147                return -ENOMEM;
 148
 149        rcar_pcie_parse_outbound_ranges(ep, pdev);
 150
 151        err = of_property_read_u8(dev->of_node, "max-functions",
 152                                  &ep->max_functions);
 153        if (err < 0 || ep->max_functions > RCAR_EPC_MAX_FUNCTIONS)
 154                ep->max_functions = RCAR_EPC_MAX_FUNCTIONS;
 155
 156        return 0;
 157}
 158
 159static int rcar_pcie_ep_write_header(struct pci_epc *epc, u8 fn, u8 vfn,
 160                                     struct pci_epf_header *hdr)
 161{
 162        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 163        struct rcar_pcie *pcie = &ep->pcie;
 164        u32 val;
 165
 166        if (!fn)
 167                val = hdr->vendorid;
 168        else
 169                val = rcar_pci_read_reg(pcie, IDSETR0);
 170        val |= hdr->deviceid << 16;
 171        rcar_pci_write_reg(pcie, val, IDSETR0);
 172
 173        val = hdr->revid;
 174        val |= hdr->progif_code << 8;
 175        val |= hdr->subclass_code << 16;
 176        val |= hdr->baseclass_code << 24;
 177        rcar_pci_write_reg(pcie, val, IDSETR1);
 178
 179        if (!fn)
 180                val = hdr->subsys_vendor_id;
 181        else
 182                val = rcar_pci_read_reg(pcie, SUBIDSETR);
 183        val |= hdr->subsys_id << 16;
 184        rcar_pci_write_reg(pcie, val, SUBIDSETR);
 185
 186        if (hdr->interrupt_pin > PCI_INTERRUPT_INTA)
 187                return -EINVAL;
 188        val = rcar_pci_read_reg(pcie, PCICONF(15));
 189        val |= (hdr->interrupt_pin << 8);
 190        rcar_pci_write_reg(pcie, val, PCICONF(15));
 191
 192        return 0;
 193}
 194
 195static int rcar_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
 196                                struct pci_epf_bar *epf_bar)
 197{
 198        int flags = epf_bar->flags | LAR_ENABLE | LAM_64BIT;
 199        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 200        u64 size = 1ULL << fls64(epf_bar->size - 1);
 201        dma_addr_t cpu_addr = epf_bar->phys_addr;
 202        enum pci_barno bar = epf_bar->barno;
 203        struct rcar_pcie *pcie = &ep->pcie;
 204        u32 mask;
 205        int idx;
 206        int err;
 207
 208        idx = find_first_zero_bit(ep->ib_window_map, ep->num_ib_windows);
 209        if (idx >= ep->num_ib_windows) {
 210                dev_err(pcie->dev, "no free inbound window\n");
 211                return -EINVAL;
 212        }
 213
 214        if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO)
 215                flags |= IO_SPACE;
 216
 217        ep->bar_to_atu[bar] = idx;
 218        /* use 64-bit BARs */
 219        set_bit(idx, ep->ib_window_map);
 220        set_bit(idx + 1, ep->ib_window_map);
 221
 222        if (cpu_addr > 0) {
 223                unsigned long nr_zeros = __ffs64(cpu_addr);
 224                u64 alignment = 1ULL << nr_zeros;
 225
 226                size = min(size, alignment);
 227        }
 228
 229        size = min(size, 1ULL << 32);
 230
 231        mask = roundup_pow_of_two(size) - 1;
 232        mask &= ~0xf;
 233
 234        rcar_pcie_set_inbound(pcie, cpu_addr,
 235                              0x0, mask | flags, idx, false);
 236
 237        err = rcar_pcie_wait_for_phyrdy(pcie);
 238        if (err) {
 239                dev_err(pcie->dev, "phy not ready\n");
 240                return -EINVAL;
 241        }
 242
 243        return 0;
 244}
 245
 246static void rcar_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn, u8 vfn,
 247                                   struct pci_epf_bar *epf_bar)
 248{
 249        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 250        enum pci_barno bar = epf_bar->barno;
 251        u32 atu_index = ep->bar_to_atu[bar];
 252
 253        rcar_pcie_set_inbound(&ep->pcie, 0x0, 0x0, 0x0, bar, false);
 254
 255        clear_bit(atu_index, ep->ib_window_map);
 256        clear_bit(atu_index + 1, ep->ib_window_map);
 257}
 258
 259static int rcar_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn,
 260                                u8 interrupts)
 261{
 262        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 263        struct rcar_pcie *pcie = &ep->pcie;
 264        u32 flags;
 265
 266        flags = rcar_pci_read_reg(pcie, MSICAP(fn));
 267        flags |= interrupts << MSICAP0_MMESCAP_OFFSET;
 268        rcar_pci_write_reg(pcie, flags, MSICAP(fn));
 269
 270        return 0;
 271}
 272
 273static int rcar_pcie_ep_get_msi(struct pci_epc *epc, u8 fn, u8 vfn)
 274{
 275        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 276        struct rcar_pcie *pcie = &ep->pcie;
 277        u32 flags;
 278
 279        flags = rcar_pci_read_reg(pcie, MSICAP(fn));
 280        if (!(flags & MSICAP0_MSIE))
 281                return -EINVAL;
 282
 283        return ((flags & MSICAP0_MMESE_MASK) >> MSICAP0_MMESE_OFFSET);
 284}
 285
 286static int rcar_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 287                                 phys_addr_t addr, u64 pci_addr, size_t size)
 288{
 289        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 290        struct rcar_pcie *pcie = &ep->pcie;
 291        struct resource_entry win;
 292        struct resource res;
 293        int window;
 294        int err;
 295
 296        /* check if we have a link. */
 297        err = rcar_pcie_wait_for_dl(pcie);
 298        if (err) {
 299                dev_err(pcie->dev, "link not up\n");
 300                return err;
 301        }
 302
 303        window = rcar_pcie_ep_get_window(ep, addr);
 304        if (window < 0) {
 305                dev_err(pcie->dev, "failed to get corresponding window\n");
 306                return -EINVAL;
 307        }
 308
 309        memset(&win, 0x0, sizeof(win));
 310        memset(&res, 0x0, sizeof(res));
 311        res.start = pci_addr;
 312        res.end = pci_addr + size - 1;
 313        res.flags = IORESOURCE_MEM;
 314        win.res = &res;
 315
 316        rcar_pcie_set_outbound(pcie, window, &win);
 317
 318        ep->ob_mapped_addr[window] = addr;
 319
 320        return 0;
 321}
 322
 323static void rcar_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, u8 vfn,
 324                                    phys_addr_t addr)
 325{
 326        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 327        struct resource_entry win;
 328        struct resource res;
 329        int idx;
 330
 331        for (idx = 0; idx < ep->num_ob_windows; idx++)
 332                if (ep->ob_mapped_addr[idx] == addr)
 333                        break;
 334
 335        if (idx >= ep->num_ob_windows)
 336                return;
 337
 338        memset(&win, 0x0, sizeof(win));
 339        memset(&res, 0x0, sizeof(res));
 340        win.res = &res;
 341        rcar_pcie_set_outbound(&ep->pcie, idx, &win);
 342
 343        ep->ob_mapped_addr[idx] = 0;
 344}
 345
 346static int rcar_pcie_ep_assert_intx(struct rcar_pcie_endpoint *ep,
 347                                    u8 fn, u8 intx)
 348{
 349        struct rcar_pcie *pcie = &ep->pcie;
 350        u32 val;
 351
 352        val = rcar_pci_read_reg(pcie, PCIEMSITXR);
 353        if ((val & PCI_MSI_FLAGS_ENABLE)) {
 354                dev_err(pcie->dev, "MSI is enabled, cannot assert INTx\n");
 355                return -EINVAL;
 356        }
 357
 358        val = rcar_pci_read_reg(pcie, PCICONF(1));
 359        if ((val & INTDIS)) {
 360                dev_err(pcie->dev, "INTx message transmission is disabled\n");
 361                return -EINVAL;
 362        }
 363
 364        val = rcar_pci_read_reg(pcie, PCIEINTXR);
 365        if ((val & ASTINTX)) {
 366                dev_err(pcie->dev, "INTx is already asserted\n");
 367                return -EINVAL;
 368        }
 369
 370        val |= ASTINTX;
 371        rcar_pci_write_reg(pcie, val, PCIEINTXR);
 372        usleep_range(1000, 1001);
 373        val = rcar_pci_read_reg(pcie, PCIEINTXR);
 374        val &= ~ASTINTX;
 375        rcar_pci_write_reg(pcie, val, PCIEINTXR);
 376
 377        return 0;
 378}
 379
 380static int rcar_pcie_ep_assert_msi(struct rcar_pcie *pcie,
 381                                   u8 fn, u8 interrupt_num)
 382{
 383        u16 msi_count;
 384        u32 val;
 385
 386        /* Check MSI enable bit */
 387        val = rcar_pci_read_reg(pcie, MSICAP(fn));
 388        if (!(val & MSICAP0_MSIE))
 389                return -EINVAL;
 390
 391        /* Get MSI numbers from MME */
 392        msi_count = ((val & MSICAP0_MMESE_MASK) >> MSICAP0_MMESE_OFFSET);
 393        msi_count = 1 << msi_count;
 394
 395        if (!interrupt_num || interrupt_num > msi_count)
 396                return -EINVAL;
 397
 398        val = rcar_pci_read_reg(pcie, PCIEMSITXR);
 399        rcar_pci_write_reg(pcie, val | (interrupt_num - 1), PCIEMSITXR);
 400
 401        return 0;
 402}
 403
 404static int rcar_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn, u8 vfn,
 405                                  enum pci_epc_irq_type type,
 406                                  u16 interrupt_num)
 407{
 408        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 409
 410        switch (type) {
 411        case PCI_EPC_IRQ_LEGACY:
 412                return rcar_pcie_ep_assert_intx(ep, fn, 0);
 413
 414        case PCI_EPC_IRQ_MSI:
 415                return rcar_pcie_ep_assert_msi(&ep->pcie, fn, interrupt_num);
 416
 417        default:
 418                return -EINVAL;
 419        }
 420}
 421
 422static int rcar_pcie_ep_start(struct pci_epc *epc)
 423{
 424        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 425
 426        rcar_pci_write_reg(&ep->pcie, MACCTLR_INIT_VAL, MACCTLR);
 427        rcar_pci_write_reg(&ep->pcie, CFINIT, PCIETCTLR);
 428
 429        return 0;
 430}
 431
 432static void rcar_pcie_ep_stop(struct pci_epc *epc)
 433{
 434        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 435
 436        rcar_pci_write_reg(&ep->pcie, 0, PCIETCTLR);
 437}
 438
 439static const struct pci_epc_features rcar_pcie_epc_features = {
 440        .linkup_notifier = false,
 441        .msi_capable = true,
 442        .msix_capable = false,
 443        /* use 64-bit BARs so mark BAR[1,3,5] as reserved */
 444        .reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
 445        .bar_fixed_64bit = 1 << BAR_0 | 1 << BAR_2 | 1 << BAR_4,
 446        .bar_fixed_size[0] = 128,
 447        .bar_fixed_size[2] = 256,
 448        .bar_fixed_size[4] = 256,
 449};
 450
 451static const struct pci_epc_features*
 452rcar_pcie_ep_get_features(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
 453{
 454        return &rcar_pcie_epc_features;
 455}
 456
 457static const struct pci_epc_ops rcar_pcie_epc_ops = {
 458        .write_header   = rcar_pcie_ep_write_header,
 459        .set_bar        = rcar_pcie_ep_set_bar,
 460        .clear_bar      = rcar_pcie_ep_clear_bar,
 461        .set_msi        = rcar_pcie_ep_set_msi,
 462        .get_msi        = rcar_pcie_ep_get_msi,
 463        .map_addr       = rcar_pcie_ep_map_addr,
 464        .unmap_addr     = rcar_pcie_ep_unmap_addr,
 465        .raise_irq      = rcar_pcie_ep_raise_irq,
 466        .start          = rcar_pcie_ep_start,
 467        .stop           = rcar_pcie_ep_stop,
 468        .get_features   = rcar_pcie_ep_get_features,
 469};
 470
 471static const struct of_device_id rcar_pcie_ep_of_match[] = {
 472        { .compatible = "renesas,r8a774c0-pcie-ep", },
 473        { .compatible = "renesas,rcar-gen3-pcie-ep" },
 474        { },
 475};
 476
 477static int rcar_pcie_ep_probe(struct platform_device *pdev)
 478{
 479        struct device *dev = &pdev->dev;
 480        struct rcar_pcie_endpoint *ep;
 481        struct rcar_pcie *pcie;
 482        struct pci_epc *epc;
 483        int err;
 484
 485        ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 486        if (!ep)
 487                return -ENOMEM;
 488
 489        pcie = &ep->pcie;
 490        pcie->dev = dev;
 491
 492        pm_runtime_enable(dev);
 493        err = pm_runtime_resume_and_get(dev);
 494        if (err < 0) {
 495                dev_err(dev, "pm_runtime_resume_and_get failed\n");
 496                goto err_pm_disable;
 497        }
 498
 499        err = rcar_pcie_ep_get_pdata(ep, pdev);
 500        if (err < 0) {
 501                dev_err(dev, "failed to request resources: %d\n", err);
 502                goto err_pm_put;
 503        }
 504
 505        ep->num_ib_windows = MAX_NR_INBOUND_MAPS;
 506        ep->ib_window_map =
 507                        devm_kcalloc(dev, BITS_TO_LONGS(ep->num_ib_windows),
 508                                     sizeof(long), GFP_KERNEL);
 509        if (!ep->ib_window_map) {
 510                err = -ENOMEM;
 511                dev_err(dev, "failed to allocate memory for inbound map\n");
 512                goto err_pm_put;
 513        }
 514
 515        ep->ob_mapped_addr = devm_kcalloc(dev, ep->num_ob_windows,
 516                                          sizeof(*ep->ob_mapped_addr),
 517                                          GFP_KERNEL);
 518        if (!ep->ob_mapped_addr) {
 519                err = -ENOMEM;
 520                dev_err(dev, "failed to allocate memory for outbound memory pointers\n");
 521                goto err_pm_put;
 522        }
 523
 524        epc = devm_pci_epc_create(dev, &rcar_pcie_epc_ops);
 525        if (IS_ERR(epc)) {
 526                dev_err(dev, "failed to create epc device\n");
 527                err = PTR_ERR(epc);
 528                goto err_pm_put;
 529        }
 530
 531        epc->max_functions = ep->max_functions;
 532        epc_set_drvdata(epc, ep);
 533
 534        rcar_pcie_ep_hw_init(pcie);
 535
 536        err = pci_epc_multi_mem_init(epc, ep->ob_window, ep->num_ob_windows);
 537        if (err < 0) {
 538                dev_err(dev, "failed to initialize the epc memory space\n");
 539                goto err_pm_put;
 540        }
 541
 542        return 0;
 543
 544err_pm_put:
 545        pm_runtime_put(dev);
 546
 547err_pm_disable:
 548        pm_runtime_disable(dev);
 549
 550        return err;
 551}
 552
 553static struct platform_driver rcar_pcie_ep_driver = {
 554        .driver = {
 555                .name = "rcar-pcie-ep",
 556                .of_match_table = rcar_pcie_ep_of_match,
 557                .suppress_bind_attrs = true,
 558        },
 559        .probe = rcar_pcie_ep_probe,
 560};
 561builtin_platform_driver(rcar_pcie_ep_driver);
 562