drivers/pci/host/pci-keystone.c

   1 /*
   2  * PCIe host controller driver for Texas Instruments Keystone SoCs
   3  *
   4  * Copyright (C) 2013-2014 Texas Instruments., Ltd.
   5  *              http://www.ti.com
   6  *
   7  * Author: Murali Karicheri <m-karicheri2@ti.com>
   8  * Implementation based on pci-exynos.c and pcie-designware.c
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/irqchip/chained_irq.h>
  16 #include <linux/clk.h>
  17 #include <linux/delay.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/irqdomain.h>
  20 #include <linux/init.h>
  21 #include <linux/msi.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/of.h>
  24 #include <linux/of_pci.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/phy/phy.h>
  27 #include <linux/resource.h>
  28 #include <linux/signal.h>
  29
  30 #include "pcie-designware.h"
  31 #include "pci-keystone.h"
  32
  33 #define DRIVER_NAME     "keystone-pcie"
  34
  35 /* driver specific constants */
  36 #define MAX_MSI_HOST_IRQS               8
  37 #define MAX_LEGACY_HOST_IRQS            4
  38
  39 /* DEV_STAT_CTRL */
  40 #define PCIE_CAP_BASE           0x70
  41
  42 /* PCIE controller device IDs */
  43 #define PCIE_RC_K2HK            0xb008
  44 #define PCIE_RC_K2E             0xb009
  45 #define PCIE_RC_K2L             0xb00a
  46
  47 #define to_keystone_pcie(x)     container_of(x, struct keystone_pcie, pp)
  48
  49 static void quirk_limit_mrrs(struct pci_dev *dev)
  50 {
  51         struct pci_bus *bus = dev->bus;
  52         struct pci_dev *bridge = bus->self;
  53         static const struct pci_device_id rc_pci_devids[] = {
  54                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK),
  55                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  56                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E),
  57                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  58                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L),
  59                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  60                 { 0, },
  61         };
  62
  63         if (pci_is_root_bus(bus))
  64                 return;
  65
  66         /* look for the host bridge */
  67         while (!pci_is_root_bus(bus)) {
  68                 bridge = bus->self;
  69                 bus = bus->parent;
  70         }
  71
  72         if (bridge) {
  73                 /*
  74                  * Keystone PCI controller has a h/w limitation of
  75                  * 256 bytes maximum read request size.  It can't handle
  76                  * anything higher than this.  So force this limit on
  77                  * all downstream devices.
  78                  */
  79                 if (pci_match_id(rc_pci_devids, bridge)) {
  80                         if (pcie_get_readrq(dev) > 256) {
  81                                 dev_info(&dev->dev, "limiting MRRS to 256\n");
  82                                 pcie_set_readrq(dev, 256);
  83                         }
  84                 }
  85         }
  86 }
  87 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs);
  88
  89 static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
  90 {
  91         struct pcie_port *pp = &ks_pcie->pp;
  92         unsigned int retries;
  93
  94         dw_pcie_setup_rc(pp);
  95
  96         if (dw_pcie_link_up(pp)) {
  97                 dev_err(pp->dev, "Link already up\n");
  98                 return 0;
  99         }
 100
 101         /* check if the link is up or not */
 102         for (retries = 0; retries < 5; retries++) {
 103                 ks_dw_pcie_initiate_link_train(ks_pcie);
 104                 if (!dw_pcie_wait_for_link(pp))
 105                         return 0;
 106         }
 107
 108         dev_err(pp->dev, "phy link never came up\n");
 109         return -ETIMEDOUT;
 110 }
 111
 112 static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 113 {
 114         unsigned int irq = irq_desc_get_irq(desc);
 115         struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 116         u32 offset = irq - ks_pcie->msi_host_irqs[0];
 117         struct pcie_port *pp = &ks_pcie->pp;
 118         struct irq_chip *chip = irq_desc_get_chip(desc);
 119
 120         dev_dbg(pp->dev, "%s, irq %d\n", __func__, irq);
 121
 122         /*
 123          * The chained irq handler installation would have replaced normal
 124          * interrupt driver handler so we need to take care of mask/unmask and
 125          * ack operation.
 126          */
 127         chained_irq_enter(chip, desc);
 128         ks_dw_pcie_handle_msi_irq(ks_pcie, offset);
 129         chained_irq_exit(chip, desc);
 130 }
 131
 132 /**
 133  * ks_pcie_legacy_irq_handler() - Handle legacy interrupt
 134  * @irq: IRQ line for legacy interrupts
 135  * @desc: Pointer to irq descriptor
 136  *
 137  * Traverse through pending legacy interrupts and invoke handler for each. Also
 138  * takes care of interrupt controller level mask/ack operation.
 139  */
 140 static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
 141 {
 142         unsigned int irq = irq_desc_get_irq(desc);
 143         struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 144         struct pcie_port *pp = &ks_pcie->pp;
 145         u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
 146         struct irq_chip *chip = irq_desc_get_chip(desc);
 147
 148         dev_dbg(pp->dev, ": Handling legacy irq %d\n", irq);
 149
 150         /*
 151          * The chained irq handler installation would have replaced normal
 152          * interrupt driver handler so we need to take care of mask/unmask and
 153          * ack operation.
 154          */
 155         chained_irq_enter(chip, desc);
 156         ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset);
 157         chained_irq_exit(chip, desc);
 158 }
 159
 160 static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 161                                            char *controller, int *num_irqs)
 162 {
 163         int temp, max_host_irqs, legacy = 1, *host_irqs;
 164         struct device *dev = ks_pcie->pp.dev;
 165         struct device_node *np_pcie = dev->of_node, **np_temp;
 166
 167         if (!strcmp(controller, "msi-interrupt-controller"))
 168                 legacy = 0;
 169
 170         if (legacy) {
 171                 np_temp = &ks_pcie->legacy_intc_np;
 172                 max_host_irqs = MAX_LEGACY_HOST_IRQS;
 173                 host_irqs = &ks_pcie->legacy_host_irqs[0];
 174         } else {
 175                 np_temp = &ks_pcie->msi_intc_np;
 176                 max_host_irqs = MAX_MSI_HOST_IRQS;
 177                 host_irqs =  &ks_pcie->msi_host_irqs[0];
 178         }
 179
 180         /* interrupt controller is in a child node */
 181         *np_temp = of_find_node_by_name(np_pcie, controller);
 182         if (!(*np_temp)) {
 183                 dev_err(dev, "Node for %s is absent\n", controller);
 184                 return -EINVAL;
 185         }
 186
 187         temp = of_irq_count(*np_temp);
 188         if (!temp) {
 189                 dev_err(dev, "No IRQ entries in %s\n", controller);
 190                 return -EINVAL;
 191         }
 192
 193         if (temp > max_host_irqs)
 194                 dev_warn(dev, "Too many %s interrupts defined %u\n",
 195                         (legacy ? "legacy" : "MSI"), temp);
 196
 197         /*
 198          * support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to
 199          * 7 (MSI)
 200          */
 201         for (temp = 0; temp < max_host_irqs; temp++) {
 202                 host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp);
 203                 if (!host_irqs[temp])
 204                         break;
 205         }
 206
 207         if (temp) {
 208                 *num_irqs = temp;
 209                 return 0;
 210         }
 211
 212         return -EINVAL;
 213 }
 214
 215 static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
 216 {
 217         int i;
 218
 219         /* Legacy IRQ */
 220         for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) {
 221                 irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i],
 222                                                  ks_pcie_legacy_irq_handler,
 223                                                  ks_pcie);
 224         }
 225         ks_dw_pcie_enable_legacy_irqs(ks_pcie);
 226
 227         /* MSI IRQ */
 228         if (IS_ENABLED(CONFIG_PCI_MSI)) {
 229                 for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) {
 230                         irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i],
 231                                                          ks_pcie_msi_irq_handler,
 232                                                          ks_pcie);
 233                 }
 234         }
 235
 236         if (ks_pcie->error_irq > 0)
 237                 ks_dw_pcie_enable_error_irq(ks_pcie->va_app_base);
 238 }
 239
 240 /*
 241  * When a PCI device does not exist during config cycles, keystone host gets a
 242  * bus error instead of returning 0xffffffff. This handler always returns 0
 243  * for this kind of faults.
 244  */
 245 static int keystone_pcie_fault(unsigned long addr, unsigned int fsr,
 246                                 struct pt_regs *regs)
 247 {
 248         unsigned long instr = *(unsigned long *) instruction_pointer(regs);
 249
 250         if ((instr & 0x0e100090) == 0x00100090) {
 251                 int reg = (instr >> 12) & 15;
 252
 253                 regs->uregs[reg] = -1;
 254                 regs->ARM_pc += 4;
 255         }
 256
 257         return 0;
 258 }
 259
 260 static void __init ks_pcie_host_init(struct pcie_port *pp)
 261 {
 262         struct keystone_pcie *ks_pcie = to_keystone_pcie(pp);
 263         u32 val;
 264
 265         ks_pcie_establish_link(ks_pcie);
 266         ks_dw_pcie_setup_rc_app_regs(ks_pcie);
 267         ks_pcie_setup_interrupts(ks_pcie);
 268         writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8),
 269                         pp->dbi_base + PCI_IO_BASE);
 270
 271         /* update the Vendor ID */
 272         writew(ks_pcie->device_id, pp->dbi_base + PCI_DEVICE_ID);
 273
 274         /* update the DEV_STAT_CTRL to publish right mrrs */
 275         val = readl(pp->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
 276         val &= ~PCI_EXP_DEVCTL_READRQ;
 277         /* set the mrrs to 256 bytes */
 278         val |= BIT(12);
 279         writel(val, pp->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
 280
 281         /*
 282          * PCIe access errors that result into OCP errors are caught by ARM as
 283          * "External aborts"
 284          */
 285         hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0,
 286                         "Asynchronous external abort");
 287 }
 288
 289 static struct pcie_host_ops keystone_pcie_host_ops = {
 290         .rd_other_conf = ks_dw_pcie_rd_other_conf,
 291         .wr_other_conf = ks_dw_pcie_wr_other_conf,
 292         .link_up = ks_dw_pcie_link_up,
 293         .host_init = ks_pcie_host_init,
 294         .msi_set_irq = ks_dw_pcie_msi_set_irq,
 295         .msi_clear_irq = ks_dw_pcie_msi_clear_irq,
 296         .get_msi_addr = ks_dw_pcie_get_msi_addr,
 297         .msi_host_init = ks_dw_pcie_msi_host_init,
 298         .scan_bus = ks_dw_pcie_v3_65_scan_bus,
 299 };
 300
 301 static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
 302 {
 303         struct keystone_pcie *ks_pcie = priv;
 304
 305         return ks_dw_pcie_handle_error_irq(ks_pcie->pp.dev,
 306                                            ks_pcie->va_app_base);
 307 }
 308
 309 static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
 310                          struct platform_device *pdev)
 311 {
 312         struct pcie_port *pp = &ks_pcie->pp;
 313         int ret;
 314
 315         ret = ks_pcie_get_irq_controller_info(ks_pcie,
 316                                         "legacy-interrupt-controller",
 317                                         &ks_pcie->num_legacy_host_irqs);
 318         if (ret)
 319                 return ret;
 320
 321         if (IS_ENABLED(CONFIG_PCI_MSI)) {
 322                 ret = ks_pcie_get_irq_controller_info(ks_pcie,
 323                                                 "msi-interrupt-controller",
 324                                                 &ks_pcie->num_msi_host_irqs);
 325                 if (ret)
 326                         return ret;
 327         }
 328
 329         /*
 330          * Index 0 is the platform interrupt for error interrupt
 331          * from RC.  This is optional.
 332          */
 333         ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
 334         if (ks_pcie->error_irq <= 0)
 335                 dev_info(&pdev->dev, "no error IRQ defined\n");
 336         else {
 337                 ret = request_irq(ks_pcie->error_irq, pcie_err_irq_handler,
 338                                   IRQF_SHARED, "pcie-error-irq", ks_pcie);
 339                 if (ret < 0) {
 340                         dev_err(&pdev->dev, "failed to request error IRQ %d\n",
 341                                 ks_pcie->error_irq);
 342                         return ret;
 343                 }
 344         }
 345
 346         pp->root_bus_nr = -1;
 347         pp->ops = &keystone_pcie_host_ops;
 348         ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
 349         if (ret) {
 350                 dev_err(&pdev->dev, "failed to initialize host\n");
 351                 return ret;
 352         }
 353
 354         return 0;
 355 }
 356
 357 static const struct of_device_id ks_pcie_of_match[] = {
 358         {
 359                 .type = "pci",
 360                 .compatible = "ti,keystone-pcie",
 361         },
 362         { },
 363 };
 364
 365 static int __exit ks_pcie_remove(struct platform_device *pdev)
 366 {
 367         struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);
 368
 369         clk_disable_unprepare(ks_pcie->clk);
 370
 371         return 0;
 372 }
 373
 374 static int __init ks_pcie_probe(struct platform_device *pdev)
 375 {
 376         struct device *dev = &pdev->dev;
 377         struct keystone_pcie *ks_pcie;
 378         struct pcie_port *pp;
 379         struct resource *res;
 380         void __iomem *reg_p;
 381         struct phy *phy;
 382         int ret;
 383
 384         ks_pcie = devm_kzalloc(&pdev->dev, sizeof(*ks_pcie),
 385                                 GFP_KERNEL);
 386         if (!ks_pcie)
 387                 return -ENOMEM;
 388
 389         pp = &ks_pcie->pp;
 390
 391         /* initialize SerDes Phy if present */
 392         phy = devm_phy_get(dev, "pcie-phy");
 393         if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
 394                 return PTR_ERR(phy);
 395
 396         if (!IS_ERR_OR_NULL(phy)) {
 397                 ret = phy_init(phy);
 398                 if (ret < 0)
 399                         return ret;
 400         }
 401
 402         /* index 2 is to read PCI DEVICE_ID */
 403         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 404         reg_p = devm_ioremap_resource(dev, res);
 405         if (IS_ERR(reg_p))
 406                 return PTR_ERR(reg_p);
 407         ks_pcie->device_id = readl(reg_p) >> 16;
 408         devm_iounmap(dev, reg_p);
 409         devm_release_mem_region(dev, res->start, resource_size(res));
 410
 411         pp->dev = dev;
 412         ks_pcie->np = dev->of_node;
 413         platform_set_drvdata(pdev, ks_pcie);
 414         ks_pcie->clk = devm_clk_get(dev, "pcie");
 415         if (IS_ERR(ks_pcie->clk)) {
 416                 dev_err(dev, "Failed to get pcie rc clock\n");
 417                 return PTR_ERR(ks_pcie->clk);
 418         }
 419         ret = clk_prepare_enable(ks_pcie->clk);
 420         if (ret)
 421                 return ret;
 422
 423         ret = ks_add_pcie_port(ks_pcie, pdev);
 424         if (ret < 0)
 425                 goto fail_clk;
 426
 427         return 0;
 428 fail_clk:
 429         clk_disable_unprepare(ks_pcie->clk);
 430
 431         return ret;
 432 }
 433
 434 static struct platform_driver ks_pcie_driver __refdata = {
 435         .probe  = ks_pcie_probe,
 436         .remove = __exit_p(ks_pcie_remove),
 437         .driver = {
 438                 .name   = "keystone-pcie",
 439                 .of_match_table = of_match_ptr(ks_pcie_of_match),
 440         },
 441 };
 442 builtin_platform_driver(ks_pcie_driver);