drivers/pci/dwc/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 /* DEV_STAT_CTRL */
  36 #define PCIE_CAP_BASE           0x70
  37
  38 /* PCIE controller device IDs */
  39 #define PCIE_RC_K2HK            0xb008
  40 #define PCIE_RC_K2E             0xb009
  41 #define PCIE_RC_K2L             0xb00a
  42
  43 #define to_keystone_pcie(x)     dev_get_drvdata((x)->dev)
  44
  45 static void quirk_limit_mrrs(struct pci_dev *dev)
  46 {
  47         struct pci_bus *bus = dev->bus;
  48         struct pci_dev *bridge = bus->self;
  49         static const struct pci_device_id rc_pci_devids[] = {
  50                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK),
  51                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  52                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E),
  53                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  54                 { PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L),
  55                  .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
  56                 { 0, },
  57         };
  58
  59         if (pci_is_root_bus(bus))
  60                 return;
  61
  62         /* look for the host bridge */
  63         while (!pci_is_root_bus(bus)) {
  64                 bridge = bus->self;
  65                 bus = bus->parent;
  66         }
  67
  68         if (bridge) {
  69                 /*
  70                  * Keystone PCI controller has a h/w limitation of
  71                  * 256 bytes maximum read request size.  It can't handle
  72                  * anything higher than this.  So force this limit on
  73                  * all downstream devices.
  74                  */
  75                 if (pci_match_id(rc_pci_devids, bridge)) {
  76                         if (pcie_get_readrq(dev) > 256) {
  77                                 dev_info(&dev->dev, "limiting MRRS to 256\n");
  78                                 pcie_set_readrq(dev, 256);
  79                         }
  80                 }
  81         }
  82 }
  83 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs);
  84
  85 static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
  86 {
  87         struct dw_pcie *pci = ks_pcie->pci;
  88         struct pcie_port *pp = &pci->pp;
  89         struct device *dev = pci->dev;
  90         unsigned int retries;
  91
  92         dw_pcie_setup_rc(pp);
  93
  94         if (dw_pcie_link_up(pci)) {
  95                 dev_err(dev, "Link already up\n");
  96                 return 0;
  97         }
  98
  99         /* check if the link is up or not */
 100         for (retries = 0; retries < 5; retries++) {
 101                 ks_dw_pcie_initiate_link_train(ks_pcie);
 102                 if (!dw_pcie_wait_for_link(pci))
 103                         return 0;
 104         }
 105
 106         dev_err(dev, "phy link never came up\n");
 107         return -ETIMEDOUT;
 108 }
 109
 110 static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 111 {
 112         unsigned int irq = irq_desc_get_irq(desc);
 113         struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 114         u32 offset = irq - ks_pcie->msi_host_irqs[0];
 115         struct dw_pcie *pci = ks_pcie->pci;
 116         struct device *dev = pci->dev;
 117         struct irq_chip *chip = irq_desc_get_chip(desc);
 118
 119         dev_dbg(dev, "%s, irq %d\n", __func__, irq);
 120
 121         /*
 122          * The chained irq handler installation would have replaced normal
 123          * interrupt driver handler so we need to take care of mask/unmask and
 124          * ack operation.
 125          */
 126         chained_irq_enter(chip, desc);
 127         ks_dw_pcie_handle_msi_irq(ks_pcie, offset);
 128         chained_irq_exit(chip, desc);
 129 }
 130
 131 /**
 132  * ks_pcie_legacy_irq_handler() - Handle legacy interrupt
 133  * @irq: IRQ line for legacy interrupts
 134  * @desc: Pointer to irq descriptor
 135  *
 136  * Traverse through pending legacy interrupts and invoke handler for each. Also
 137  * takes care of interrupt controller level mask/ack operation.
 138  */
 139 static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
 140 {
 141         unsigned int irq = irq_desc_get_irq(desc);
 142         struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 143         struct dw_pcie *pci = ks_pcie->pci;
 144         struct device *dev = pci->dev;
 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(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->pci->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 = PCI_NUM_INTX;
 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);
 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 int __init ks_pcie_host_init(struct pcie_port *pp)
 261 {
 262         struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 263         struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
 264         u32 val;
 265
 266         ks_pcie_establish_link(ks_pcie);
 267         ks_dw_pcie_setup_rc_app_regs(ks_pcie);
 268         ks_pcie_setup_interrupts(ks_pcie);
 269         writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8),
 270                         pci->dbi_base + PCI_IO_BASE);
 271
 272         /* update the Vendor ID */
 273         writew(ks_pcie->device_id, pci->dbi_base + PCI_DEVICE_ID);
 274
 275         /* update the DEV_STAT_CTRL to publish right mrrs */
 276         val = readl(pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
 277         val &= ~PCI_EXP_DEVCTL_READRQ;
 278         /* set the mrrs to 256 bytes */
 279         val |= BIT(12);
 280         writel(val, pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
 281
 282         /*
 283          * PCIe access errors that result into OCP errors are caught by ARM as
 284          * "External aborts"
 285          */
 286         hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0,
 287                         "Asynchronous external abort");
 288
 289         return 0;
 290 }
 291
 292 static const struct dw_pcie_host_ops keystone_pcie_host_ops = {
 293         .rd_other_conf = ks_dw_pcie_rd_other_conf,
 294         .wr_other_conf = ks_dw_pcie_wr_other_conf,
 295         .host_init = ks_pcie_host_init,
 296         .msi_set_irq = ks_dw_pcie_msi_set_irq,
 297         .msi_clear_irq = ks_dw_pcie_msi_clear_irq,
 298         .get_msi_addr = ks_dw_pcie_get_msi_addr,
 299         .msi_host_init = ks_dw_pcie_msi_host_init,
 300         .scan_bus = ks_dw_pcie_v3_65_scan_bus,
 301 };
 302
 303 static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
 304 {
 305         struct keystone_pcie *ks_pcie = priv;
 306
 307         return ks_dw_pcie_handle_error_irq(ks_pcie);
 308 }
 309
 310 static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
 311                          struct platform_device *pdev)
 312 {
 313         struct dw_pcie *pci = ks_pcie->pci;
 314         struct pcie_port *pp = &pci->pp;
 315         struct device *dev = &pdev->dev;
 316         int ret;
 317
 318         ret = ks_pcie_get_irq_controller_info(ks_pcie,
 319                                         "legacy-interrupt-controller",
 320                                         &ks_pcie->num_legacy_host_irqs);
 321         if (ret)
 322                 return ret;
 323
 324         if (IS_ENABLED(CONFIG_PCI_MSI)) {
 325                 ret = ks_pcie_get_irq_controller_info(ks_pcie,
 326                                                 "msi-interrupt-controller",
 327                                                 &ks_pcie->num_msi_host_irqs);
 328                 if (ret)
 329                         return ret;
 330         }
 331
 332         /*
 333          * Index 0 is the platform interrupt for error interrupt
 334          * from RC.  This is optional.
 335          */
 336         ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
 337         if (ks_pcie->error_irq <= 0)
 338                 dev_info(dev, "no error IRQ defined\n");
 339         else {
 340                 ret = request_irq(ks_pcie->error_irq, pcie_err_irq_handler,
 341                                   IRQF_SHARED, "pcie-error-irq", ks_pcie);
 342                 if (ret < 0) {
 343                         dev_err(dev, "failed to request error IRQ %d\n",
 344                                 ks_pcie->error_irq);
 345                         return ret;
 346                 }
 347         }
 348
 349         pp->root_bus_nr = -1;
 350         pp->ops = &keystone_pcie_host_ops;
 351         ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
 352         if (ret) {
 353                 dev_err(dev, "failed to initialize host\n");
 354                 return ret;
 355         }
 356
 357         return 0;
 358 }
 359
 360 static const struct of_device_id ks_pcie_of_match[] = {
 361         {
 362                 .type = "pci",
 363                 .compatible = "ti,keystone-pcie",
 364         },
 365         { },
 366 };
 367
 368 static const struct dw_pcie_ops dw_pcie_ops = {
 369         .link_up = ks_dw_pcie_link_up,
 370 };
 371
 372 static int __exit ks_pcie_remove(struct platform_device *pdev)
 373 {
 374         struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);
 375
 376         clk_disable_unprepare(ks_pcie->clk);
 377
 378         return 0;
 379 }
 380
 381 static int __init ks_pcie_probe(struct platform_device *pdev)
 382 {
 383         struct device *dev = &pdev->dev;
 384         struct dw_pcie *pci;
 385         struct keystone_pcie *ks_pcie;
 386         struct resource *res;
 387         void __iomem *reg_p;
 388         struct phy *phy;
 389         int ret;
 390
 391         ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
 392         if (!ks_pcie)
 393                 return -ENOMEM;
 394
 395         pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
 396         if (!pci)
 397                 return -ENOMEM;
 398
 399         pci->dev = dev;
 400         pci->ops = &dw_pcie_ops;
 401
 402         ks_pcie->pci = pci;
 403
 404         /* initialize SerDes Phy if present */
 405         phy = devm_phy_get(dev, "pcie-phy");
 406         if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
 407                 return PTR_ERR(phy);
 408
 409         if (!IS_ERR_OR_NULL(phy)) {
 410                 ret = phy_init(phy);
 411                 if (ret < 0)
 412                         return ret;
 413         }
 414
 415         /* index 2 is to read PCI DEVICE_ID */
 416         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 417         reg_p = devm_ioremap_resource(dev, res);
 418         if (IS_ERR(reg_p))
 419                 return PTR_ERR(reg_p);
 420         ks_pcie->device_id = readl(reg_p) >> 16;
 421         devm_iounmap(dev, reg_p);
 422         devm_release_mem_region(dev, res->start, resource_size(res));
 423
 424         ks_pcie->np = dev->of_node;
 425         platform_set_drvdata(pdev, ks_pcie);
 426         ks_pcie->clk = devm_clk_get(dev, "pcie");
 427         if (IS_ERR(ks_pcie->clk)) {
 428                 dev_err(dev, "Failed to get pcie rc clock\n");
 429                 return PTR_ERR(ks_pcie->clk);
 430         }
 431         ret = clk_prepare_enable(ks_pcie->clk);
 432         if (ret)
 433                 return ret;
 434
 435         platform_set_drvdata(pdev, ks_pcie);
 436
 437         ret = ks_add_pcie_port(ks_pcie, pdev);
 438         if (ret < 0)
 439                 goto fail_clk;
 440
 441         return 0;
 442 fail_clk:
 443         clk_disable_unprepare(ks_pcie->clk);
 444
 445         return ret;
 446 }
 447
 448 static struct platform_driver ks_pcie_driver __refdata = {
 449         .probe  = ks_pcie_probe,
 450         .remove = __exit_p(ks_pcie_remove),
 451         .driver = {
 452                 .name   = "keystone-pcie",
 453                 .of_match_table = of_match_ptr(ks_pcie_of_match),
 454         },
 455 };
 456 builtin_platform_driver(ks_pcie_driver);