arch/mips/pci/pci-ar71xx.c

   1 /*
   2  *  Atheros AR71xx PCI host controller driver
   3  *
   4  *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
   5  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   6  *
   7  *  Parts of this file are based on Atheros' 2.6.15 BSP
   8  *
   9  *  This program is free software; you can redistribute it and/or modify it
  10  *  under the terms of the GNU General Public License version 2 as published
  11  *  by the Free Software Foundation.
  12  */
  13
  14 #include <linux/resource.h>
  15 #include <linux/types.h>
  16 #include <linux/delay.h>
  17 #include <linux/bitops.h>
  18 #include <linux/pci.h>
  19 #include <linux/pci_regs.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23
  24 #include <asm/mach-ath79/ar71xx_regs.h>
  25 #include <asm/mach-ath79/ath79.h>
  26
  27 #define AR71XX_PCI_REG_CRP_AD_CBE       0x00
  28 #define AR71XX_PCI_REG_CRP_WRDATA       0x04
  29 #define AR71XX_PCI_REG_CRP_RDDATA       0x08
  30 #define AR71XX_PCI_REG_CFG_AD           0x0c
  31 #define AR71XX_PCI_REG_CFG_CBE          0x10
  32 #define AR71XX_PCI_REG_CFG_WRDATA       0x14
  33 #define AR71XX_PCI_REG_CFG_RDDATA       0x18
  34 #define AR71XX_PCI_REG_PCI_ERR          0x1c
  35 #define AR71XX_PCI_REG_PCI_ERR_ADDR     0x20
  36 #define AR71XX_PCI_REG_AHB_ERR          0x24
  37 #define AR71XX_PCI_REG_AHB_ERR_ADDR     0x28
  38
  39 #define AR71XX_PCI_CRP_CMD_WRITE        0x00010000
  40 #define AR71XX_PCI_CRP_CMD_READ         0x00000000
  41 #define AR71XX_PCI_CFG_CMD_READ         0x0000000a
  42 #define AR71XX_PCI_CFG_CMD_WRITE        0x0000000b
  43
  44 #define AR71XX_PCI_INT_CORE             BIT(4)
  45 #define AR71XX_PCI_INT_DEV2             BIT(2)
  46 #define AR71XX_PCI_INT_DEV1             BIT(1)
  47 #define AR71XX_PCI_INT_DEV0             BIT(0)
  48
  49 #define AR71XX_PCI_IRQ_COUNT            5
  50
  51 struct ar71xx_pci_controller {
  52         void __iomem *cfg_base;
  53         int irq;
  54         int irq_base;
  55         struct pci_controller pci_ctrl;
  56         struct resource io_res;
  57         struct resource mem_res;
  58 };
  59
  60 /* Byte lane enable bits */
  61 static const u8 ar71xx_pci_ble_table[4][4] = {
  62         {0x0, 0xf, 0xf, 0xf},
  63         {0xe, 0xd, 0xb, 0x7},
  64         {0xc, 0xf, 0x3, 0xf},
  65         {0xf, 0xf, 0xf, 0xf},
  66 };
  67
  68 static const u32 ar71xx_pci_read_mask[8] = {
  69         0, 0xff, 0xffff, 0, 0xffffffff, 0, 0, 0
  70 };
  71
  72 static inline u32 ar71xx_pci_get_ble(int where, int size, int local)
  73 {
  74         u32 t;
  75
  76         t = ar71xx_pci_ble_table[size & 3][where & 3];
  77         BUG_ON(t == 0xf);
  78         t <<= (local) ? 20 : 4;
  79
  80         return t;
  81 }
  82
  83 static inline u32 ar71xx_pci_bus_addr(struct pci_bus *bus, unsigned int devfn,
  84                                       int where)
  85 {
  86         u32 ret;
  87
  88         if (!bus->number) {
  89                 /* type 0 */
  90                 ret = (1 << PCI_SLOT(devfn)) | (PCI_FUNC(devfn) << 8) |
  91                       (where & ~3);
  92         } else {
  93                 /* type 1 */
  94                 ret = (bus->number << 16) | (PCI_SLOT(devfn) << 11) |
  95                       (PCI_FUNC(devfn) << 8) | (where & ~3) | 1;
  96         }
  97
  98         return ret;
  99 }
 100
 101 static inline struct ar71xx_pci_controller *
 102 pci_bus_to_ar71xx_controller(struct pci_bus *bus)
 103 {
 104         struct pci_controller *hose;
 105
 106         hose = (struct pci_controller *) bus->sysdata;
 107         return container_of(hose, struct ar71xx_pci_controller, pci_ctrl);
 108 }
 109
 110 static int ar71xx_pci_check_error(struct ar71xx_pci_controller *apc, int quiet)
 111 {
 112         void __iomem *base = apc->cfg_base;
 113         u32 pci_err;
 114         u32 ahb_err;
 115
 116         pci_err = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR) & 3;
 117         if (pci_err) {
 118                 if (!quiet) {
 119                         u32 addr;
 120
 121                         addr = __raw_readl(base + AR71XX_PCI_REG_PCI_ERR_ADDR);
 122                         pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
 123                                 "PCI", pci_err, addr);
 124                 }
 125
 126                 /* clear PCI error status */
 127                 __raw_writel(pci_err, base + AR71XX_PCI_REG_PCI_ERR);
 128         }
 129
 130         ahb_err = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR) & 1;
 131         if (ahb_err) {
 132                 if (!quiet) {
 133                         u32 addr;
 134
 135                         addr = __raw_readl(base + AR71XX_PCI_REG_AHB_ERR_ADDR);
 136                         pr_crit("ar71xx: %s bus error %d at addr 0x%x\n",
 137                                 "AHB", ahb_err, addr);
 138                 }
 139
 140                 /* clear AHB error status */
 141                 __raw_writel(ahb_err, base + AR71XX_PCI_REG_AHB_ERR);
 142         }
 143
 144         return !!(ahb_err | pci_err);
 145 }
 146
 147 static inline void ar71xx_pci_local_write(struct ar71xx_pci_controller *apc,
 148                                           int where, int size, u32 value)
 149 {
 150         void __iomem *base = apc->cfg_base;
 151         u32 ad_cbe;
 152
 153         value = value << (8 * (where & 3));
 154
 155         ad_cbe = AR71XX_PCI_CRP_CMD_WRITE | (where & ~3);
 156         ad_cbe |= ar71xx_pci_get_ble(where, size, 1);
 157
 158         __raw_writel(ad_cbe, base + AR71XX_PCI_REG_CRP_AD_CBE);
 159         __raw_writel(value, base + AR71XX_PCI_REG_CRP_WRDATA);
 160 }
 161
 162 static inline int ar71xx_pci_set_cfgaddr(struct pci_bus *bus,
 163                                          unsigned int devfn,
 164                                          int where, int size, u32 cmd)
 165 {
 166         struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
 167         void __iomem *base = apc->cfg_base;
 168         u32 addr;
 169
 170         addr = ar71xx_pci_bus_addr(bus, devfn, where);
 171
 172         __raw_writel(addr, base + AR71XX_PCI_REG_CFG_AD);
 173         __raw_writel(cmd | ar71xx_pci_get_ble(where, size, 0),
 174                      base + AR71XX_PCI_REG_CFG_CBE);
 175
 176         return ar71xx_pci_check_error(apc, 1);
 177 }
 178
 179 static int ar71xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
 180                                   int where, int size, u32 *value)
 181 {
 182         struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
 183         void __iomem *base = apc->cfg_base;
 184         u32 data;
 185         int err;
 186         int ret;
 187
 188         ret = PCIBIOS_SUCCESSFUL;
 189         data = ~0;
 190
 191         err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
 192                                      AR71XX_PCI_CFG_CMD_READ);
 193         if (err)
 194                 ret = PCIBIOS_DEVICE_NOT_FOUND;
 195         else
 196                 data = __raw_readl(base + AR71XX_PCI_REG_CFG_RDDATA);
 197
 198         *value = (data >> (8 * (where & 3))) & ar71xx_pci_read_mask[size & 7];
 199
 200         return ret;
 201 }
 202
 203 static int ar71xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
 204                                    int where, int size, u32 value)
 205 {
 206         struct ar71xx_pci_controller *apc = pci_bus_to_ar71xx_controller(bus);
 207         void __iomem *base = apc->cfg_base;
 208         int err;
 209         int ret;
 210
 211         value = value << (8 * (where & 3));
 212         ret = PCIBIOS_SUCCESSFUL;
 213
 214         err = ar71xx_pci_set_cfgaddr(bus, devfn, where, size,
 215                                      AR71XX_PCI_CFG_CMD_WRITE);
 216         if (err)
 217                 ret = PCIBIOS_DEVICE_NOT_FOUND;
 218         else
 219                 __raw_writel(value, base + AR71XX_PCI_REG_CFG_WRDATA);
 220
 221         return ret;
 222 }
 223
 224 static struct pci_ops ar71xx_pci_ops = {
 225         .read   = ar71xx_pci_read_config,
 226         .write  = ar71xx_pci_write_config,
 227 };
 228
 229 static void ar71xx_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
 230 {
 231         struct ar71xx_pci_controller *apc;
 232         void __iomem *base = ath79_reset_base;
 233         u32 pending;
 234
 235         apc = irq_desc_get_handler_data(desc);
 236
 237         pending = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_STATUS) &
 238                   __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 239
 240         if (pending & AR71XX_PCI_INT_DEV0)
 241                 generic_handle_irq(apc->irq_base + 0);
 242
 243         else if (pending & AR71XX_PCI_INT_DEV1)
 244                 generic_handle_irq(apc->irq_base + 1);
 245
 246         else if (pending & AR71XX_PCI_INT_DEV2)
 247                 generic_handle_irq(apc->irq_base + 2);
 248
 249         else if (pending & AR71XX_PCI_INT_CORE)
 250                 generic_handle_irq(apc->irq_base + 4);
 251
 252         else
 253                 spurious_interrupt();
 254 }
 255
 256 static void ar71xx_pci_irq_unmask(struct irq_data *d)
 257 {
 258         struct ar71xx_pci_controller *apc;
 259         unsigned int irq;
 260         void __iomem *base = ath79_reset_base;
 261         u32 t;
 262
 263         apc = irq_data_get_irq_chip_data(d);
 264         irq = d->irq - apc->irq_base;
 265
 266         t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 267         __raw_writel(t | (1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 268
 269         /* flush write */
 270         __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 271 }
 272
 273 static void ar71xx_pci_irq_mask(struct irq_data *d)
 274 {
 275         struct ar71xx_pci_controller *apc;
 276         unsigned int irq;
 277         void __iomem *base = ath79_reset_base;
 278         u32 t;
 279
 280         apc = irq_data_get_irq_chip_data(d);
 281         irq = d->irq - apc->irq_base;
 282
 283         t = __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 284         __raw_writel(t & ~(1 << irq), base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 285
 286         /* flush write */
 287         __raw_readl(base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 288 }
 289
 290 static struct irq_chip ar71xx_pci_irq_chip = {
 291         .name           = "AR71XX PCI",
 292         .irq_mask       = ar71xx_pci_irq_mask,
 293         .irq_unmask     = ar71xx_pci_irq_unmask,
 294         .irq_mask_ack   = ar71xx_pci_irq_mask,
 295 };
 296
 297 static void ar71xx_pci_irq_init(struct ar71xx_pci_controller *apc)
 298 {
 299         void __iomem *base = ath79_reset_base;
 300         int i;
 301
 302         __raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_ENABLE);
 303         __raw_writel(0, base + AR71XX_RESET_REG_PCI_INT_STATUS);
 304
 305         BUILD_BUG_ON(ATH79_PCI_IRQ_COUNT < AR71XX_PCI_IRQ_COUNT);
 306
 307         apc->irq_base = ATH79_PCI_IRQ_BASE;
 308         for (i = apc->irq_base;
 309              i < apc->irq_base + AR71XX_PCI_IRQ_COUNT; i++) {
 310                 irq_set_chip_and_handler(i, &ar71xx_pci_irq_chip,
 311                                          handle_level_irq);
 312                 irq_set_chip_data(i, apc);
 313         }
 314
 315         irq_set_chained_handler_and_data(apc->irq, ar71xx_pci_irq_handler,
 316                                          apc);
 317 }
 318
 319 static void ar71xx_pci_reset(void)
 320 {
 321         ath79_device_reset_set(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
 322         mdelay(100);
 323
 324         ath79_device_reset_clear(AR71XX_RESET_PCI_BUS | AR71XX_RESET_PCI_CORE);
 325         mdelay(100);
 326
 327         ath79_ddr_set_pci_windows();
 328         mdelay(100);
 329 }
 330
 331 static int ar71xx_pci_probe(struct platform_device *pdev)
 332 {
 333         struct ar71xx_pci_controller *apc;
 334         struct resource *res;
 335         u32 t;
 336
 337         apc = devm_kzalloc(&pdev->dev, sizeof(struct ar71xx_pci_controller),
 338                            GFP_KERNEL);
 339         if (!apc)
 340                 return -ENOMEM;
 341
 342         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg_base");
 343         apc->cfg_base = devm_ioremap_resource(&pdev->dev, res);
 344         if (IS_ERR(apc->cfg_base))
 345                 return PTR_ERR(apc->cfg_base);
 346
 347         apc->irq = platform_get_irq(pdev, 0);
 348         if (apc->irq < 0)
 349                 return -EINVAL;
 350
 351         res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
 352         if (!res)
 353                 return -EINVAL;
 354
 355         apc->io_res.parent = res;
 356         apc->io_res.name = "PCI IO space";
 357         apc->io_res.start = res->start;
 358         apc->io_res.end = res->end;
 359         apc->io_res.flags = IORESOURCE_IO;
 360
 361         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
 362         if (!res)
 363                 return -EINVAL;
 364
 365         apc->mem_res.parent = res;
 366         apc->mem_res.name = "PCI memory space";
 367         apc->mem_res.start = res->start;
 368         apc->mem_res.end = res->end;
 369         apc->mem_res.flags = IORESOURCE_MEM;
 370
 371         ar71xx_pci_reset();
 372
 373         /* setup COMMAND register */
 374         t = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE
 375           | PCI_COMMAND_PARITY | PCI_COMMAND_SERR | PCI_COMMAND_FAST_BACK;
 376         ar71xx_pci_local_write(apc, PCI_COMMAND, 4, t);
 377
 378         /* clear bus errors */
 379         ar71xx_pci_check_error(apc, 1);
 380
 381         ar71xx_pci_irq_init(apc);
 382
 383         apc->pci_ctrl.pci_ops = &ar71xx_pci_ops;
 384         apc->pci_ctrl.mem_resource = &apc->mem_res;
 385         apc->pci_ctrl.io_resource = &apc->io_res;
 386
 387         register_pci_controller(&apc->pci_ctrl);
 388
 389         return 0;
 390 }
 391
 392 static struct platform_driver ar71xx_pci_driver = {
 393         .probe = ar71xx_pci_probe,
 394         .driver = {
 395                 .name = "ar71xx-pci",
 396         },
 397 };
 398
 399 static int __init ar71xx_pci_init(void)
 400 {
 401         return platform_driver_register(&ar71xx_pci_driver);
 402 }
 403
 404 postcore_initcall(ar71xx_pci_init);