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/clk.h>
  10#include <linux/delay.h>
  11#include <linux/of_address.h>
  12#include <linux/of_irq.h>
  13#include <linux/of_pci.h>
  14#include <linux/of_platform.h>
  15#include <linux/pci.h>
  16#include <linux/pci-epc.h>
  17#include <linux/phy/phy.h>
  18#include <linux/platform_device.h>
  19
  20#include "pcie-rcar.h"
  21
  22#define RCAR_EPC_MAX_FUNCTIONS          1
  23
  24/* Structure representing the PCIe interface */
  25struct rcar_pcie_endpoint {
  26        struct rcar_pcie        pcie;
  27        phys_addr_t             *ob_mapped_addr;
  28        struct pci_epc_mem_window *ob_window;
  29        u8                      max_functions;
  30        unsigned int            bar_to_atu[MAX_NR_INBOUND_MAPS];
  31        unsigned long           *ib_window_map;
  32        u32                     num_ib_windows;
  33        u32                     num_ob_windows;
  34};
  35
  36static void rcar_pcie_ep_hw_init(struct rcar_pcie *pcie)
  37{
  38        u32 val;
  39
  40        rcar_pci_write_reg(pcie, 0, PCIETCTLR);
  41
  42        /* Set endpoint mode */
  43        rcar_pci_write_reg(pcie, 0, PCIEMSR);
  44
  45        /* Initialize default capabilities. */
  46        rcar_rmw32(pcie, REXPCAP(0), 0xff, PCI_CAP_ID_EXP);
  47        rcar_rmw32(pcie, REXPCAP(PCI_EXP_FLAGS),
  48                   PCI_EXP_FLAGS_TYPE, PCI_EXP_TYPE_ENDPOINT << 4);
  49        rcar_rmw32(pcie, RCONF(PCI_HEADER_TYPE), 0x7f,
  50                   PCI_HEADER_TYPE_NORMAL);
  51
  52        /* Write out the physical slot number = 0 */
  53        rcar_rmw32(pcie, REXPCAP(PCI_EXP_SLTCAP), PCI_EXP_SLTCAP_PSN, 0);
  54
  55        val = rcar_pci_read_reg(pcie, EXPCAP(1));
  56        /* device supports fixed 128 bytes MPSS */
  57        val &= ~GENMASK(2, 0);
  58        rcar_pci_write_reg(pcie, val, EXPCAP(1));
  59
  60        val = rcar_pci_read_reg(pcie, EXPCAP(2));
  61        /* read requests size 128 bytes */
  62        val &= ~GENMASK(14, 12);
  63        /* payload size 128 bytes */
  64        val &= ~GENMASK(7, 5);
  65        rcar_pci_write_reg(pcie, val, EXPCAP(2));
  66
  67        /* Set target link speed to 5.0 GT/s */
  68        rcar_rmw32(pcie, EXPCAP(12), PCI_EXP_LNKSTA_CLS,
  69                   PCI_EXP_LNKSTA_CLS_5_0GB);
  70
  71        /* Set the completion timer timeout to the maximum 50ms. */
  72        rcar_rmw32(pcie, TLCTLR + 1, 0x3f, 50);
  73
  74        /* Terminate list of capabilities (Next Capability Offset=0) */
  75        rcar_rmw32(pcie, RVCCAP(0), 0xfff00000, 0);
  76
  77        /* flush modifications */
  78        wmb();
  79}
  80
  81static int rcar_pcie_ep_get_window(struct rcar_pcie_endpoint *ep,
  82                                   phys_addr_t addr)
  83{
  84        int i;
  85
  86        for (i = 0; i < ep->num_ob_windows; i++)
  87                if (ep->ob_window[i].phys_base == addr)
  88                        return i;
  89
  90        return -EINVAL;
  91}
  92
  93static int rcar_pcie_parse_outbound_ranges(struct rcar_pcie_endpoint *ep,
  94                                           struct platform_device *pdev)
  95{
  96        struct rcar_pcie *pcie = &ep->pcie;
  97        char outbound_name[10];
  98        struct resource *res;
  99        unsigned int i = 0;
 100
 101        ep->num_ob_windows = 0;
 102        for (i = 0; i < RCAR_PCI_MAX_RESOURCES; i++) {
 103                sprintf(outbound_name, "memory%u", i);
 104                res = platform_get_resource_byname(pdev,
 105                                                   IORESOURCE_MEM,
 106                                                   outbound_name);
 107                if (!res) {
 108                        dev_err(pcie->dev, "missing outbound window %u\n", i);
 109                        return -EINVAL;
 110                }
 111                if (!devm_request_mem_region(&pdev->dev, res->start,
 112                                             resource_size(res),
 113                                             outbound_name)) {
 114                        dev_err(pcie->dev, "Cannot request memory region %s.\n",
 115                                outbound_name);
 116                        return -EIO;
 117                }
 118
 119                ep->ob_window[i].phys_base = res->start;
 120                ep->ob_window[i].size = resource_size(res);
 121                /* controller doesn't support multiple allocation
 122                 * from same window, so set page_size to window size
 123                 */
 124                ep->ob_window[i].page_size = resource_size(res);
 125        }
 126        ep->num_ob_windows = i;
 127
 128        return 0;
 129}
 130
 131static int rcar_pcie_ep_get_pdata(struct rcar_pcie_endpoint *ep,
 132                                  struct platform_device *pdev)
 133{
 134        struct rcar_pcie *pcie = &ep->pcie;
 135        struct pci_epc_mem_window *window;
 136        struct device *dev = pcie->dev;
 137        struct resource res;
 138        int err;
 139
 140        err = of_address_to_resource(dev->of_node, 0, &res);
 141        if (err)
 142                return err;
 143        pcie->base = devm_ioremap_resource(dev, &res);
 144        if (IS_ERR(pcie->base))
 145                return PTR_ERR(pcie->base);
 146
 147        ep->ob_window = devm_kcalloc(dev, RCAR_PCI_MAX_RESOURCES,
 148                                     sizeof(*window), GFP_KERNEL);
 149        if (!ep->ob_window)
 150                return -ENOMEM;
 151
 152        rcar_pcie_parse_outbound_ranges(ep, pdev);
 153
 154        err = of_property_read_u8(dev->of_node, "max-functions",
 155                                  &ep->max_functions);
 156        if (err < 0 || ep->max_functions > RCAR_EPC_MAX_FUNCTIONS)
 157                ep->max_functions = RCAR_EPC_MAX_FUNCTIONS;
 158
 159        return 0;
 160}
 161
 162static int rcar_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
 163                                     struct pci_epf_header *hdr)
 164{
 165        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 166        struct rcar_pcie *pcie = &ep->pcie;
 167        u32 val;
 168
 169        if (!fn)
 170                val = hdr->vendorid;
 171        else
 172                val = rcar_pci_read_reg(pcie, IDSETR0);
 173        val |= hdr->deviceid << 16;
 174        rcar_pci_write_reg(pcie, val, IDSETR0);
 175
 176        val = hdr->revid;
 177        val |= hdr->progif_code << 8;
 178        val |= hdr->subclass_code << 16;
 179        val |= hdr->baseclass_code << 24;
 180        rcar_pci_write_reg(pcie, val, IDSETR1);
 181
 182        if (!fn)
 183                val = hdr->subsys_vendor_id;
 184        else
 185                val = rcar_pci_read_reg(pcie, SUBIDSETR);
 186        val |= hdr->subsys_id << 16;
 187        rcar_pci_write_reg(pcie, val, SUBIDSETR);
 188
 189        if (hdr->interrupt_pin > PCI_INTERRUPT_INTA)
 190                return -EINVAL;
 191        val = rcar_pci_read_reg(pcie, PCICONF(15));
 192        val |= (hdr->interrupt_pin << 8);
 193        rcar_pci_write_reg(pcie, val, PCICONF(15));
 194
 195        return 0;
 196}
 197
 198static int rcar_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no,
 199                                struct pci_epf_bar *epf_bar)
 200{
 201        int flags = epf_bar->flags | LAR_ENABLE | LAM_64BIT;
 202        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 203        u64 size = 1ULL << fls64(epf_bar->size - 1);
 204        dma_addr_t cpu_addr = epf_bar->phys_addr;
 205        enum pci_barno bar = epf_bar->barno;
 206        struct rcar_pcie *pcie = &ep->pcie;
 207        u32 mask;
 208        int idx;
 209        int err;
 210
 211        idx = find_first_zero_bit(ep->ib_window_map, ep->num_ib_windows);
 212        if (idx >= ep->num_ib_windows) {
 213                dev_err(pcie->dev, "no free inbound window\n");
 214                return -EINVAL;
 215        }
 216
 217        if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO)
 218                flags |= IO_SPACE;
 219
 220        ep->bar_to_atu[bar] = idx;
 221        /* use 64-bit BARs */
 222        set_bit(idx, ep->ib_window_map);
 223        set_bit(idx + 1, ep->ib_window_map);
 224
 225        if (cpu_addr > 0) {
 226                unsigned long nr_zeros = __ffs64(cpu_addr);
 227                u64 alignment = 1ULL << nr_zeros;
 228
 229                size = min(size, alignment);
 230        }
 231
 232        size = min(size, 1ULL << 32);
 233
 234        mask = roundup_pow_of_two(size) - 1;
 235        mask &= ~0xf;
 236
 237        rcar_pcie_set_inbound(pcie, cpu_addr,
 238                              0x0, mask | flags, idx, false);
 239
 240        err = rcar_pcie_wait_for_phyrdy(pcie);
 241        if (err) {
 242                dev_err(pcie->dev, "phy not ready\n");
 243                return -EINVAL;
 244        }
 245
 246        return 0;
 247}
 248
 249static void rcar_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
 250                                   struct pci_epf_bar *epf_bar)
 251{
 252        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 253        enum pci_barno bar = epf_bar->barno;
 254        u32 atu_index = ep->bar_to_atu[bar];
 255
 256        rcar_pcie_set_inbound(&ep->pcie, 0x0, 0x0, 0x0, bar, false);
 257
 258        clear_bit(atu_index, ep->ib_window_map);
 259        clear_bit(atu_index + 1, ep->ib_window_map);
 260}
 261
 262static int rcar_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 interrupts)
 263{
 264        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 265        struct rcar_pcie *pcie = &ep->pcie;
 266        u32 flags;
 267
 268        flags = rcar_pci_read_reg(pcie, MSICAP(fn));
 269        flags |= interrupts << MSICAP0_MMESCAP_OFFSET;
 270        rcar_pci_write_reg(pcie, flags, MSICAP(fn));
 271
 272        return 0;
 273}
 274
 275static int rcar_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
 276{
 277        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 278        struct rcar_pcie *pcie = &ep->pcie;
 279        u32 flags;
 280
 281        flags = rcar_pci_read_reg(pcie, MSICAP(fn));
 282        if (!(flags & MSICAP0_MSIE))
 283                return -EINVAL;
 284
 285        return ((flags & MSICAP0_MMESE_MASK) >> MSICAP0_MMESE_OFFSET);
 286}
 287
 288static int rcar_pcie_ep_map_addr(struct pci_epc *epc, u8 fn,
 289                                 phys_addr_t addr, u64 pci_addr, size_t size)
 290{
 291        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 292        struct rcar_pcie *pcie = &ep->pcie;
 293        struct resource_entry win;
 294        struct resource res;
 295        int window;
 296        int err;
 297
 298        /* check if we have a link. */
 299        err = rcar_pcie_wait_for_dl(pcie);
 300        if (err) {
 301                dev_err(pcie->dev, "link not up\n");
 302                return err;
 303        }
 304
 305        window = rcar_pcie_ep_get_window(ep, addr);
 306        if (window < 0) {
 307                dev_err(pcie->dev, "failed to get corresponding window\n");
 308                return -EINVAL;
 309        }
 310
 311        memset(&win, 0x0, sizeof(win));
 312        memset(&res, 0x0, sizeof(res));
 313        res.start = pci_addr;
 314        res.end = pci_addr + size - 1;
 315        res.flags = IORESOURCE_MEM;
 316        win.res = &res;
 317
 318        rcar_pcie_set_outbound(pcie, window, &win);
 319
 320        ep->ob_mapped_addr[window] = addr;
 321
 322        return 0;
 323}
 324
 325static void rcar_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn,
 326                                    phys_addr_t addr)
 327{
 328        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 329        struct resource_entry win;
 330        struct resource res;
 331        int idx;
 332
 333        for (idx = 0; idx < ep->num_ob_windows; idx++)
 334                if (ep->ob_mapped_addr[idx] == addr)
 335                        break;
 336
 337        if (idx >= ep->num_ob_windows)
 338                return;
 339
 340        memset(&win, 0x0, sizeof(win));
 341        memset(&res, 0x0, sizeof(res));
 342        win.res = &res;
 343        rcar_pcie_set_outbound(&ep->pcie, idx, &win);
 344
 345        ep->ob_mapped_addr[idx] = 0;
 346}
 347
 348static int rcar_pcie_ep_assert_intx(struct rcar_pcie_endpoint *ep,
 349                                    u8 fn, u8 intx)
 350{
 351        struct rcar_pcie *pcie = &ep->pcie;
 352        u32 val;
 353
 354        val = rcar_pci_read_reg(pcie, PCIEMSITXR);
 355        if ((val & PCI_MSI_FLAGS_ENABLE)) {
 356                dev_err(pcie->dev, "MSI is enabled, cannot assert INTx\n");
 357                return -EINVAL;
 358        }
 359
 360        val = rcar_pci_read_reg(pcie, PCICONF(1));
 361        if ((val & INTDIS)) {
 362                dev_err(pcie->dev, "INTx message transmission is disabled\n");
 363                return -EINVAL;
 364        }
 365
 366        val = rcar_pci_read_reg(pcie, PCIEINTXR);
 367        if ((val & ASTINTX)) {
 368                dev_err(pcie->dev, "INTx is already asserted\n");
 369                return -EINVAL;
 370        }
 371
 372        val |= ASTINTX;
 373        rcar_pci_write_reg(pcie, val, PCIEINTXR);
 374        usleep_range(1000, 1001);
 375        val = rcar_pci_read_reg(pcie, PCIEINTXR);
 376        val &= ~ASTINTX;
 377        rcar_pci_write_reg(pcie, val, PCIEINTXR);
 378
 379        return 0;
 380}
 381
 382static int rcar_pcie_ep_assert_msi(struct rcar_pcie *pcie,
 383                                   u8 fn, u8 interrupt_num)
 384{
 385        u16 msi_count;
 386        u32 val;
 387
 388        /* Check MSI enable bit */
 389        val = rcar_pci_read_reg(pcie, MSICAP(fn));
 390        if (!(val & MSICAP0_MSIE))
 391                return -EINVAL;
 392
 393        /* Get MSI numbers from MME */
 394        msi_count = ((val & MSICAP0_MMESE_MASK) >> MSICAP0_MMESE_OFFSET);
 395        msi_count = 1 << msi_count;
 396
 397        if (!interrupt_num || interrupt_num > msi_count)
 398                return -EINVAL;
 399
 400        val = rcar_pci_read_reg(pcie, PCIEMSITXR);
 401        rcar_pci_write_reg(pcie, val | (interrupt_num - 1), PCIEMSITXR);
 402
 403        return 0;
 404}
 405
 406static int rcar_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
 407                                  enum pci_epc_irq_type type,
 408                                  u16 interrupt_num)
 409{
 410        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 411
 412        switch (type) {
 413        case PCI_EPC_IRQ_LEGACY:
 414                return rcar_pcie_ep_assert_intx(ep, fn, 0);
 415
 416        case PCI_EPC_IRQ_MSI:
 417                return rcar_pcie_ep_assert_msi(&ep->pcie, fn, interrupt_num);
 418
 419        default:
 420                return -EINVAL;
 421        }
 422}
 423
 424static int rcar_pcie_ep_start(struct pci_epc *epc)
 425{
 426        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 427
 428        rcar_pci_write_reg(&ep->pcie, MACCTLR_INIT_VAL, MACCTLR);
 429        rcar_pci_write_reg(&ep->pcie, CFINIT, PCIETCTLR);
 430
 431        return 0;
 432}
 433
 434static void rcar_pcie_ep_stop(struct pci_epc *epc)
 435{
 436        struct rcar_pcie_endpoint *ep = epc_get_drvdata(epc);
 437
 438        rcar_pci_write_reg(&ep->pcie, 0, PCIETCTLR);
 439}
 440
 441static const struct pci_epc_features rcar_pcie_epc_features = {
 442        .linkup_notifier = false,
 443        .msi_capable = true,
 444        .msix_capable = false,
 445        /* use 64-bit BARs so mark BAR[1,3,5] as reserved */
 446        .reserved_bar = 1 << BAR_1 | 1 << BAR_3 | 1 << BAR_5,
 447        .bar_fixed_64bit = 1 << BAR_0 | 1 << BAR_2 | 1 << BAR_4,
 448        .bar_fixed_size[0] = 128,
 449        .bar_fixed_size[2] = 256,
 450        .bar_fixed_size[4] = 256,
 451};
 452
 453static const struct pci_epc_features*
 454rcar_pcie_ep_get_features(struct pci_epc *epc, u8 func_no)
 455{
 456        return &rcar_pcie_epc_features;
 457}
 458
 459static const struct pci_epc_ops rcar_pcie_epc_ops = {
 460        .write_header   = rcar_pcie_ep_write_header,
 461        .set_bar        = rcar_pcie_ep_set_bar,
 462        .clear_bar      = rcar_pcie_ep_clear_bar,
 463        .set_msi        = rcar_pcie_ep_set_msi,
 464        .get_msi        = rcar_pcie_ep_get_msi,
 465        .map_addr       = rcar_pcie_ep_map_addr,
 466        .unmap_addr     = rcar_pcie_ep_unmap_addr,
 467        .raise_irq      = rcar_pcie_ep_raise_irq,
 468        .start          = rcar_pcie_ep_start,
 469        .stop           = rcar_pcie_ep_stop,
 470        .get_features   = rcar_pcie_ep_get_features,
 471};
 472
 473static const struct of_device_id rcar_pcie_ep_of_match[] = {
 474        { .compatible = "renesas,r8a774c0-pcie-ep", },
 475        { .compatible = "renesas,rcar-gen3-pcie-ep" },
 476        { },
 477};
 478
 479static int rcar_pcie_ep_probe(struct platform_device *pdev)
 480{
 481        struct device *dev = &pdev->dev;
 482        struct rcar_pcie_endpoint *ep;
 483        struct rcar_pcie *pcie;
 484        struct pci_epc *epc;
 485        int err;
 486
 487        ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 488        if (!ep)
 489                return -ENOMEM;
 490
 491        pcie = &ep->pcie;
 492        pcie->dev = dev;
 493
 494        pm_runtime_enable(dev);
 495        err = pm_runtime_get_sync(dev);
 496        if (err < 0) {
 497                dev_err(dev, "pm_runtime_get_sync failed\n");
 498                goto err_pm_disable;
 499        }
 500
 501        err = rcar_pcie_ep_get_pdata(ep, pdev);
 502        if (err < 0) {
 503                dev_err(dev, "failed to request resources: %d\n", err);
 504                goto err_pm_put;
 505        }
 506
 507        ep->num_ib_windows = MAX_NR_INBOUND_MAPS;
 508        ep->ib_window_map =
 509                        devm_kcalloc(dev, BITS_TO_LONGS(ep->num_ib_windows),
 510                                     sizeof(long), GFP_KERNEL);
 511        if (!ep->ib_window_map) {
 512                err = -ENOMEM;
 513                dev_err(dev, "failed to allocate memory for inbound map\n");
 514                goto err_pm_put;
 515        }
 516
 517        ep->ob_mapped_addr = devm_kcalloc(dev, ep->num_ob_windows,
 518                                          sizeof(*ep->ob_mapped_addr),
 519                                          GFP_KERNEL);
 520        if (!ep->ob_mapped_addr) {
 521                err = -ENOMEM;
 522                dev_err(dev, "failed to allocate memory for outbound memory pointers\n");
 523                goto err_pm_put;
 524        }
 525
 526        epc = devm_pci_epc_create(dev, &rcar_pcie_epc_ops);
 527        if (IS_ERR(epc)) {
 528                dev_err(dev, "failed to create epc device\n");
 529                err = PTR_ERR(epc);
 530                goto err_pm_put;
 531        }
 532
 533        epc->max_functions = ep->max_functions;
 534        epc_set_drvdata(epc, ep);
 535
 536        rcar_pcie_ep_hw_init(pcie);
 537
 538        err = pci_epc_multi_mem_init(epc, ep->ob_window, ep->num_ob_windows);
 539        if (err < 0) {
 540                dev_err(dev, "failed to initialize the epc memory space\n");
 541                goto err_pm_put;
 542        }
 543
 544        return 0;
 545
 546err_pm_put:
 547        pm_runtime_put(dev);
 548
 549err_pm_disable:
 550        pm_runtime_disable(dev);
 551
 552        return err;
 553}
 554
 555static struct platform_driver rcar_pcie_ep_driver = {
 556        .driver = {
 557                .name = "rcar-pcie-ep",
 558                .of_match_table = rcar_pcie_ep_of_match,
 559                .suppress_bind_attrs = true,
 560        },
 561        .probe = rcar_pcie_ep_probe,
 562};
 563builtin_platform_driver(rcar_pcie_ep_driver);
 564