arch/mips/pci/ops-loongson3.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/types.h>
   3 #include <linux/pci.h>
   4 #include <linux/kernel.h>
   5
   6 #include <asm/mips-boards/bonito64.h>
   7
   8 #include <loongson.h>
   9
  10 #define PCI_ACCESS_READ  0
  11 #define PCI_ACCESS_WRITE 1
  12
  13 #define HT1LO_PCICFG_BASE      0x1a000000
  14 #define HT1LO_PCICFG_BASE_TP1  0x1b000000
  15
  16 static int loongson3_pci_config_access(unsigned char access_type,
  17                 struct pci_bus *bus, unsigned int devfn,
  18                 int where, u32 *data)
  19 {
  20         unsigned char busnum = bus->number;
  21         u_int64_t addr, type;
  22         void *addrp;
  23         int device = PCI_SLOT(devfn);
  24         int function = PCI_FUNC(devfn);
  25         int reg = where & ~3;
  26
  27         addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
  28         if (busnum == 0) {
  29                 if (device > 31)
  30                         return PCIBIOS_DEVICE_NOT_FOUND;
  31                 addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE) | (addr & 0xffff));
  32                 type = 0;
  33
  34         } else {
  35                 addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE_TP1) | (addr));
  36                 type = 0x10000;
  37         }
  38
  39         if (access_type == PCI_ACCESS_WRITE)
  40                 writel(*data, addrp);
  41         else {
  42                 *data = readl(addrp);
  43                 if (*data == 0xffffffff) {
  44                         *data = -1;
  45                         return PCIBIOS_DEVICE_NOT_FOUND;
  46                 }
  47         }
  48         return PCIBIOS_SUCCESSFUL;
  49 }
  50
  51 static int loongson3_pci_pcibios_read(struct pci_bus *bus, unsigned int devfn,
  52                                  int where, int size, u32 *val)
  53 {
  54         u32 data = 0;
  55         int ret = loongson3_pci_config_access(PCI_ACCESS_READ,
  56                         bus, devfn, where, &data);
  57
  58         if (ret != PCIBIOS_SUCCESSFUL)
  59                 return ret;
  60
  61         if (size == 1)
  62                 *val = (data >> ((where & 3) << 3)) & 0xff;
  63         else if (size == 2)
  64                 *val = (data >> ((where & 3) << 3)) & 0xffff;
  65         else
  66                 *val = data;
  67
  68         return PCIBIOS_SUCCESSFUL;
  69 }
  70
  71 static int loongson3_pci_pcibios_write(struct pci_bus *bus, unsigned int devfn,
  72                                   int where, int size, u32 val)
  73 {
  74         u32 data = 0;
  75         int ret;
  76
  77         if (size == 4)
  78                 data = val;
  79         else {
  80                 ret = loongson3_pci_config_access(PCI_ACCESS_READ,
  81                                 bus, devfn, where, &data);
  82                 if (ret != PCIBIOS_SUCCESSFUL)
  83                         return ret;
  84
  85                 if (size == 1)
  86                         data = (data & ~(0xff << ((where & 3) << 3))) |
  87                             (val << ((where & 3) << 3));
  88                 else if (size == 2)
  89                         data = (data & ~(0xffff << ((where & 3) << 3))) |
  90                             (val << ((where & 3) << 3));
  91         }
  92
  93         ret = loongson3_pci_config_access(PCI_ACCESS_WRITE,
  94                         bus, devfn, where, &data);
  95
  96         return ret;
  97 }
  98
  99 struct pci_ops loongson_pci_ops = {
 100         .read = loongson3_pci_pcibios_read,
 101         .write = loongson3_pci_pcibios_write
 102 };