linux/drivers/pci/controller/pci-rcar-gen2.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  pci-rcar-gen2: internal PCI bus support
   4 *
   5 * Copyright (C) 2013 Renesas Solutions Corp.
   6 * Copyright (C) 2013 Cogent Embedded, Inc.
   7 *
   8 * Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
   9 */
  10
  11#include <linux/delay.h>
  12#include <linux/init.h>
  13#include <linux/interrupt.h>
  14#include <linux/io.h>
  15#include <linux/kernel.h>
  16#include <linux/of_address.h>
  17#include <linux/of_pci.h>
  18#include <linux/pci.h>
  19#include <linux/platform_device.h>
  20#include <linux/pm_runtime.h>
  21#include <linux/sizes.h>
  22#include <linux/slab.h>
  23
  24#include "../pci.h"
  25
  26/* AHB-PCI Bridge PCI communication registers */
  27#define RCAR_AHBPCI_PCICOM_OFFSET       0x800
  28
  29#define RCAR_PCIAHB_WIN1_CTR_REG        (RCAR_AHBPCI_PCICOM_OFFSET + 0x00)
  30#define RCAR_PCIAHB_WIN2_CTR_REG        (RCAR_AHBPCI_PCICOM_OFFSET + 0x04)
  31#define RCAR_PCIAHB_PREFETCH0           0x0
  32#define RCAR_PCIAHB_PREFETCH4           0x1
  33#define RCAR_PCIAHB_PREFETCH8           0x2
  34#define RCAR_PCIAHB_PREFETCH16          0x3
  35
  36#define RCAR_AHBPCI_WIN1_CTR_REG        (RCAR_AHBPCI_PCICOM_OFFSET + 0x10)
  37#define RCAR_AHBPCI_WIN2_CTR_REG        (RCAR_AHBPCI_PCICOM_OFFSET + 0x14)
  38#define RCAR_AHBPCI_WIN_CTR_MEM         (3 << 1)
  39#define RCAR_AHBPCI_WIN_CTR_CFG         (5 << 1)
  40#define RCAR_AHBPCI_WIN1_HOST           (1 << 30)
  41#define RCAR_AHBPCI_WIN1_DEVICE         (1 << 31)
  42
  43#define RCAR_PCI_INT_ENABLE_REG         (RCAR_AHBPCI_PCICOM_OFFSET + 0x20)
  44#define RCAR_PCI_INT_STATUS_REG         (RCAR_AHBPCI_PCICOM_OFFSET + 0x24)
  45#define RCAR_PCI_INT_SIGTABORT          (1 << 0)
  46#define RCAR_PCI_INT_SIGRETABORT        (1 << 1)
  47#define RCAR_PCI_INT_REMABORT           (1 << 2)
  48#define RCAR_PCI_INT_PERR               (1 << 3)
  49#define RCAR_PCI_INT_SIGSERR            (1 << 4)
  50#define RCAR_PCI_INT_RESERR             (1 << 5)
  51#define RCAR_PCI_INT_WIN1ERR            (1 << 12)
  52#define RCAR_PCI_INT_WIN2ERR            (1 << 13)
  53#define RCAR_PCI_INT_A                  (1 << 16)
  54#define RCAR_PCI_INT_B                  (1 << 17)
  55#define RCAR_PCI_INT_PME                (1 << 19)
  56#define RCAR_PCI_INT_ALLERRORS (RCAR_PCI_INT_SIGTABORT          | \
  57                                RCAR_PCI_INT_SIGRETABORT        | \
  58                                RCAR_PCI_INT_REMABORT           | \
  59                                RCAR_PCI_INT_PERR               | \
  60                                RCAR_PCI_INT_SIGSERR            | \
  61                                RCAR_PCI_INT_RESERR             | \
  62                                RCAR_PCI_INT_WIN1ERR            | \
  63                                RCAR_PCI_INT_WIN2ERR)
  64
  65#define RCAR_AHB_BUS_CTR_REG            (RCAR_AHBPCI_PCICOM_OFFSET + 0x30)
  66#define RCAR_AHB_BUS_MMODE_HTRANS       (1 << 0)
  67#define RCAR_AHB_BUS_MMODE_BYTE_BURST   (1 << 1)
  68#define RCAR_AHB_BUS_MMODE_WR_INCR      (1 << 2)
  69#define RCAR_AHB_BUS_MMODE_HBUS_REQ     (1 << 7)
  70#define RCAR_AHB_BUS_SMODE_READYCTR     (1 << 17)
  71#define RCAR_AHB_BUS_MODE               (RCAR_AHB_BUS_MMODE_HTRANS |    \
  72                                        RCAR_AHB_BUS_MMODE_BYTE_BURST | \
  73                                        RCAR_AHB_BUS_MMODE_WR_INCR |    \
  74                                        RCAR_AHB_BUS_MMODE_HBUS_REQ |   \
  75                                        RCAR_AHB_BUS_SMODE_READYCTR)
  76
  77#define RCAR_USBCTR_REG                 (RCAR_AHBPCI_PCICOM_OFFSET + 0x34)
  78#define RCAR_USBCTR_USBH_RST            (1 << 0)
  79#define RCAR_USBCTR_PCICLK_MASK         (1 << 1)
  80#define RCAR_USBCTR_PLL_RST             (1 << 2)
  81#define RCAR_USBCTR_DIRPD               (1 << 8)
  82#define RCAR_USBCTR_PCIAHB_WIN2_EN      (1 << 9)
  83#define RCAR_USBCTR_PCIAHB_WIN1_256M    (0 << 10)
  84#define RCAR_USBCTR_PCIAHB_WIN1_512M    (1 << 10)
  85#define RCAR_USBCTR_PCIAHB_WIN1_1G      (2 << 10)
  86#define RCAR_USBCTR_PCIAHB_WIN1_2G      (3 << 10)
  87#define RCAR_USBCTR_PCIAHB_WIN1_MASK    (3 << 10)
  88
  89#define RCAR_PCI_ARBITER_CTR_REG        (RCAR_AHBPCI_PCICOM_OFFSET + 0x40)
  90#define RCAR_PCI_ARBITER_PCIREQ0        (1 << 0)
  91#define RCAR_PCI_ARBITER_PCIREQ1        (1 << 1)
  92#define RCAR_PCI_ARBITER_PCIBP_MODE     (1 << 12)
  93
  94#define RCAR_PCI_UNIT_REV_REG           (RCAR_AHBPCI_PCICOM_OFFSET + 0x48)
  95
  96struct rcar_pci_priv {
  97        struct device *dev;
  98        void __iomem *reg;
  99        struct resource mem_res;
 100        struct resource *cfg_res;
 101        unsigned busnr;
 102        int irq;
 103        unsigned long window_size;
 104        unsigned long window_addr;
 105        unsigned long window_pci;
 106};
 107
 108/* PCI configuration space operations */
 109static void __iomem *rcar_pci_cfg_base(struct pci_bus *bus, unsigned int devfn,
 110                                       int where)
 111{
 112        struct pci_sys_data *sys = bus->sysdata;
 113        struct rcar_pci_priv *priv = sys->private_data;
 114        int slot, val;
 115
 116        if (sys->busnr != bus->number || PCI_FUNC(devfn))
 117                return NULL;
 118
 119        /* Only one EHCI/OHCI device built-in */
 120        slot = PCI_SLOT(devfn);
 121        if (slot > 2)
 122                return NULL;
 123
 124        /* bridge logic only has registers to 0x40 */
 125        if (slot == 0x0 && where >= 0x40)
 126                return NULL;
 127
 128        val = slot ? RCAR_AHBPCI_WIN1_DEVICE | RCAR_AHBPCI_WIN_CTR_CFG :
 129                     RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG;
 130
 131        iowrite32(val, priv->reg + RCAR_AHBPCI_WIN1_CTR_REG);
 132        return priv->reg + (slot >> 1) * 0x100 + where;
 133}
 134
 135/* PCI interrupt mapping */
 136static int rcar_pci_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 137{
 138        struct pci_sys_data *sys = dev->bus->sysdata;
 139        struct rcar_pci_priv *priv = sys->private_data;
 140        int irq;
 141
 142        irq = of_irq_parse_and_map_pci(dev, slot, pin);
 143        if (!irq)
 144                irq = priv->irq;
 145
 146        return irq;
 147}
 148
 149#ifdef CONFIG_PCI_DEBUG
 150/* if debug enabled, then attach an error handler irq to the bridge */
 151
 152static irqreturn_t rcar_pci_err_irq(int irq, void *pw)
 153{
 154        struct rcar_pci_priv *priv = pw;
 155        struct device *dev = priv->dev;
 156        u32 status = ioread32(priv->reg + RCAR_PCI_INT_STATUS_REG);
 157
 158        if (status & RCAR_PCI_INT_ALLERRORS) {
 159                dev_err(dev, "error irq: status %08x\n", status);
 160
 161                /* clear the error(s) */
 162                iowrite32(status & RCAR_PCI_INT_ALLERRORS,
 163                          priv->reg + RCAR_PCI_INT_STATUS_REG);
 164                return IRQ_HANDLED;
 165        }
 166
 167        return IRQ_NONE;
 168}
 169
 170static void rcar_pci_setup_errirq(struct rcar_pci_priv *priv)
 171{
 172        struct device *dev = priv->dev;
 173        int ret;
 174        u32 val;
 175
 176        ret = devm_request_irq(dev, priv->irq, rcar_pci_err_irq,
 177                               IRQF_SHARED, "error irq", priv);
 178        if (ret) {
 179                dev_err(dev, "cannot claim IRQ for error handling\n");
 180                return;
 181        }
 182
 183        val = ioread32(priv->reg + RCAR_PCI_INT_ENABLE_REG);
 184        val |= RCAR_PCI_INT_ALLERRORS;
 185        iowrite32(val, priv->reg + RCAR_PCI_INT_ENABLE_REG);
 186}
 187#else
 188static inline void rcar_pci_setup_errirq(struct rcar_pci_priv *priv) { }
 189#endif
 190
 191/* PCI host controller setup */
 192static int rcar_pci_setup(int nr, struct pci_sys_data *sys)
 193{
 194        struct rcar_pci_priv *priv = sys->private_data;
 195        struct device *dev = priv->dev;
 196        void __iomem *reg = priv->reg;
 197        u32 val;
 198        int ret;
 199
 200        pm_runtime_enable(dev);
 201        pm_runtime_get_sync(dev);
 202
 203        val = ioread32(reg + RCAR_PCI_UNIT_REV_REG);
 204        dev_info(dev, "PCI: bus%u revision %x\n", sys->busnr, val);
 205
 206        /* Disable Direct Power Down State and assert reset */
 207        val = ioread32(reg + RCAR_USBCTR_REG) & ~RCAR_USBCTR_DIRPD;
 208        val |= RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST;
 209        iowrite32(val, reg + RCAR_USBCTR_REG);
 210        udelay(4);
 211
 212        /* De-assert reset and reset PCIAHB window1 size */
 213        val &= ~(RCAR_USBCTR_PCIAHB_WIN1_MASK | RCAR_USBCTR_PCICLK_MASK |
 214                 RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST);
 215
 216        /* Setup PCIAHB window1 size */
 217        switch (priv->window_size) {
 218        case SZ_2G:
 219                val |= RCAR_USBCTR_PCIAHB_WIN1_2G;
 220                break;
 221        case SZ_1G:
 222                val |= RCAR_USBCTR_PCIAHB_WIN1_1G;
 223                break;
 224        case SZ_512M:
 225                val |= RCAR_USBCTR_PCIAHB_WIN1_512M;
 226                break;
 227        default:
 228                pr_warn("unknown window size %ld - defaulting to 256M\n",
 229                        priv->window_size);
 230                priv->window_size = SZ_256M;
 231                /* fall-through */
 232        case SZ_256M:
 233                val |= RCAR_USBCTR_PCIAHB_WIN1_256M;
 234                break;
 235        }
 236        iowrite32(val, reg + RCAR_USBCTR_REG);
 237
 238        /* Configure AHB master and slave modes */
 239        iowrite32(RCAR_AHB_BUS_MODE, reg + RCAR_AHB_BUS_CTR_REG);
 240
 241        /* Configure PCI arbiter */
 242        val = ioread32(reg + RCAR_PCI_ARBITER_CTR_REG);
 243        val |= RCAR_PCI_ARBITER_PCIREQ0 | RCAR_PCI_ARBITER_PCIREQ1 |
 244               RCAR_PCI_ARBITER_PCIBP_MODE;
 245        iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);
 246
 247        /* PCI-AHB mapping */
 248        iowrite32(priv->window_addr | RCAR_PCIAHB_PREFETCH16,
 249                  reg + RCAR_PCIAHB_WIN1_CTR_REG);
 250
 251        /* AHB-PCI mapping: OHCI/EHCI registers */
 252        val = priv->mem_res.start | RCAR_AHBPCI_WIN_CTR_MEM;
 253        iowrite32(val, reg + RCAR_AHBPCI_WIN2_CTR_REG);
 254
 255        /* Enable AHB-PCI bridge PCI configuration access */
 256        iowrite32(RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG,
 257                  reg + RCAR_AHBPCI_WIN1_CTR_REG);
 258        /* Set PCI-AHB Window1 address */
 259        iowrite32(priv->window_pci | PCI_BASE_ADDRESS_MEM_PREFETCH,
 260                  reg + PCI_BASE_ADDRESS_1);
 261        /* Set AHB-PCI bridge PCI communication area address */
 262        val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
 263        iowrite32(val, reg + PCI_BASE_ADDRESS_0);
 264
 265        val = ioread32(reg + PCI_COMMAND);
 266        val |= PCI_COMMAND_SERR | PCI_COMMAND_PARITY |
 267               PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
 268        iowrite32(val, reg + PCI_COMMAND);
 269
 270        /* Enable PCI interrupts */
 271        iowrite32(RCAR_PCI_INT_A | RCAR_PCI_INT_B | RCAR_PCI_INT_PME,
 272                  reg + RCAR_PCI_INT_ENABLE_REG);
 273
 274        if (priv->irq > 0)
 275                rcar_pci_setup_errirq(priv);
 276
 277        /* Add PCI resources */
 278        pci_add_resource(&sys->resources, &priv->mem_res);
 279        ret = devm_request_pci_bus_resources(dev, &sys->resources);
 280        if (ret < 0)
 281                return ret;
 282
 283        /* Setup bus number based on platform device id / of bus-range */
 284        sys->busnr = priv->busnr;
 285        return 1;
 286}
 287
 288static struct pci_ops rcar_pci_ops = {
 289        .map_bus = rcar_pci_cfg_base,
 290        .read   = pci_generic_config_read,
 291        .write  = pci_generic_config_write,
 292};
 293
 294static int rcar_pci_parse_map_dma_ranges(struct rcar_pci_priv *pci,
 295                                         struct device_node *np)
 296{
 297        struct device *dev = pci->dev;
 298        struct of_pci_range range;
 299        struct of_pci_range_parser parser;
 300        int index = 0;
 301
 302        /* Failure to parse is ok as we fall back to defaults */
 303        if (of_pci_dma_range_parser_init(&parser, np))
 304                return 0;
 305
 306        /* Get the dma-ranges from DT */
 307        for_each_of_pci_range(&parser, &range) {
 308                /* Hardware only allows one inbound 32-bit range */
 309                if (index)
 310                        return -EINVAL;
 311
 312                pci->window_addr = (unsigned long)range.cpu_addr;
 313                pci->window_pci = (unsigned long)range.pci_addr;
 314                pci->window_size = (unsigned long)range.size;
 315
 316                /* Catch HW limitations */
 317                if (!(range.flags & IORESOURCE_PREFETCH)) {
 318                        dev_err(dev, "window must be prefetchable\n");
 319                        return -EINVAL;
 320                }
 321                if (pci->window_addr) {
 322                        u32 lowaddr = 1 << (ffs(pci->window_addr) - 1);
 323
 324                        if (lowaddr < pci->window_size) {
 325                                dev_err(dev, "invalid window size/addr\n");
 326                                return -EINVAL;
 327                        }
 328                }
 329                index++;
 330        }
 331
 332        return 0;
 333}
 334
 335static int rcar_pci_probe(struct platform_device *pdev)
 336{
 337        struct device *dev = &pdev->dev;
 338        struct resource *cfg_res, *mem_res;
 339        struct rcar_pci_priv *priv;
 340        void __iomem *reg;
 341        struct hw_pci hw;
 342        void *hw_private[1];
 343
 344        cfg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 345        reg = devm_ioremap_resource(dev, cfg_res);
 346        if (IS_ERR(reg))
 347                return PTR_ERR(reg);
 348
 349        mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 350        if (!mem_res || !mem_res->start)
 351                return -ENODEV;
 352
 353        if (mem_res->start & 0xFFFF)
 354                return -EINVAL;
 355
 356        priv = devm_kzalloc(dev, sizeof(struct rcar_pci_priv), GFP_KERNEL);
 357        if (!priv)
 358                return -ENOMEM;
 359
 360        priv->mem_res = *mem_res;
 361        priv->cfg_res = cfg_res;
 362
 363        priv->irq = platform_get_irq(pdev, 0);
 364        priv->reg = reg;
 365        priv->dev = dev;
 366
 367        if (priv->irq < 0) {
 368                dev_err(dev, "no valid irq found\n");
 369                return priv->irq;
 370        }
 371
 372        /* default window addr and size if not specified in DT */
 373        priv->window_addr = 0x40000000;
 374        priv->window_pci = 0x40000000;
 375        priv->window_size = SZ_1G;
 376
 377        if (dev->of_node) {
 378                struct resource busnr;
 379                int ret;
 380
 381                ret = of_pci_parse_bus_range(dev->of_node, &busnr);
 382                if (ret < 0) {
 383                        dev_err(dev, "failed to parse bus-range\n");
 384                        return ret;
 385                }
 386
 387                priv->busnr = busnr.start;
 388                if (busnr.end != busnr.start)
 389                        dev_warn(dev, "only one bus number supported\n");
 390
 391                ret = rcar_pci_parse_map_dma_ranges(priv, dev->of_node);
 392                if (ret < 0) {
 393                        dev_err(dev, "failed to parse dma-range\n");
 394                        return ret;
 395                }
 396        } else {
 397                priv->busnr = pdev->id;
 398        }
 399
 400        hw_private[0] = priv;
 401        memset(&hw, 0, sizeof(hw));
 402        hw.nr_controllers = ARRAY_SIZE(hw_private);
 403        hw.io_optional = 1;
 404        hw.private_data = hw_private;
 405        hw.map_irq = rcar_pci_map_irq;
 406        hw.ops = &rcar_pci_ops;
 407        hw.setup = rcar_pci_setup;
 408        pci_common_init_dev(dev, &hw);
 409        return 0;
 410}
 411
 412static const struct of_device_id rcar_pci_of_match[] = {
 413        { .compatible = "renesas,pci-r8a7790", },
 414        { .compatible = "renesas,pci-r8a7791", },
 415        { .compatible = "renesas,pci-r8a7794", },
 416        { .compatible = "renesas,pci-rcar-gen2", },
 417        { },
 418};
 419
 420static struct platform_driver rcar_pci_driver = {
 421        .driver = {
 422                .name = "pci-rcar-gen2",
 423                .suppress_bind_attrs = true,
 424                .of_match_table = rcar_pci_of_match,
 425        },
 426        .probe = rcar_pci_probe,
 427};
 428builtin_platform_driver(rcar_pci_driver);
 429