arch/mips/pci/ops-bonito64.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
   4  *      All rights reserved.
   5  *      Authors: Carsten Langgaard <carstenl@mips.com>
   6  *               Maciej W. Rozycki <macro@mips.com>
   7  *
   8  * MIPS boards specific PCI support.
   9  */
  10 #include <linux/types.h>
  11 #include <linux/pci.h>
  12 #include <linux/kernel.h>
  13
  14 #include <asm/mips-boards/bonito64.h>
  15
  16 #define PCI_ACCESS_READ  0
  17 #define PCI_ACCESS_WRITE 1
  18
  19 #define CFG_SPACE_REG(offset) (void *)CKSEG1ADDR(_pcictrl_bonito_pcicfg + (offset))
  20 #define ID_SEL_BEGIN 10
  21 #define MAX_DEV_NUM (31 - ID_SEL_BEGIN)
  22
  23
  24 static int bonito64_pcibios_config_access(unsigned char access_type,
  25                                       struct pci_bus *bus,
  26                                       unsigned int devfn, int where,
  27                                       u32 * data)
  28 {
  29         u32 busnum = bus->number;
  30         u32 addr, type;
  31         u32 dummy;
  32         void *addrp;
  33         int device = PCI_SLOT(devfn);
  34         int function = PCI_FUNC(devfn);
  35         int reg = where & ~3;
  36
  37         if (busnum == 0) {
  38                 /* Type 0 configuration for onboard PCI bus */
  39                 if (device > MAX_DEV_NUM)
  40                         return -1;
  41
  42                 addr = (1 << (device + ID_SEL_BEGIN)) | (function << 8) | reg;
  43                 type = 0;
  44         } else {
  45                 /* Type 1 configuration for offboard PCI bus */
  46                 addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
  47                 type = 0x10000;
  48         }
  49
  50         /* Clear aborts */
  51         BONITO_PCICMD |= BONITO_PCICMD_MABORT_CLR | BONITO_PCICMD_MTABORT_CLR;
  52
  53         BONITO_PCIMAP_CFG = (addr >> 16) | type;
  54
  55         /* Flush Bonito register block */
  56         dummy = BONITO_PCIMAP_CFG;
  57         mmiowb();
  58
  59         addrp = CFG_SPACE_REG(addr & 0xffff);
  60         if (access_type == PCI_ACCESS_WRITE) {
  61                 writel(cpu_to_le32(*data), addrp);
  62                 /* Wait till done */
  63                 while (BONITO_PCIMSTAT & 0xF);
  64         } else {
  65                 *data = le32_to_cpu(readl(addrp));
  66         }
  67
  68         /* Detect Master/Target abort */
  69         if (BONITO_PCICMD & (BONITO_PCICMD_MABORT_CLR |
  70                              BONITO_PCICMD_MTABORT_CLR)) {
  71                 /* Error occurred */
  72
  73                 /* Clear bits */
  74                 BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
  75                                   BONITO_PCICMD_MTABORT_CLR);
  76
  77                 return -1;
  78         }
  79
  80         return 0;
  81
  82 }
  83
  84
  85 /*
  86  * We can't address 8 and 16 bit words directly.  Instead we have to
  87  * read/write a 32bit word and mask/modify the data we actually want.
  88  */
  89 static int bonito64_pcibios_read(struct pci_bus *bus, unsigned int devfn,
  90                              int where, int size, u32 * val)
  91 {
  92         u32 data = 0;
  93
  94         if ((size == 2) && (where & 1))
  95                 return PCIBIOS_BAD_REGISTER_NUMBER;
  96         else if ((size == 4) && (where & 3))
  97                 return PCIBIOS_BAD_REGISTER_NUMBER;
  98
  99         if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
 100                                        &data))
 101                 return -1;
 102
 103         if (size == 1)
 104                 *val = (data >> ((where & 3) << 3)) & 0xff;
 105         else if (size == 2)
 106                 *val = (data >> ((where & 3) << 3)) & 0xffff;
 107         else
 108                 *val = data;
 109
 110         return PCIBIOS_SUCCESSFUL;
 111 }
 112
 113 static int bonito64_pcibios_write(struct pci_bus *bus, unsigned int devfn,
 114                               int where, int size, u32 val)
 115 {
 116         u32 data = 0;
 117
 118         if ((size == 2) && (where & 1))
 119                 return PCIBIOS_BAD_REGISTER_NUMBER;
 120         else if ((size == 4) && (where & 3))
 121                 return PCIBIOS_BAD_REGISTER_NUMBER;
 122
 123         if (size == 4)
 124                 data = val;
 125         else {
 126                 if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
 127                                                where, &data))
 128                         return -1;
 129
 130                 if (size == 1)
 131                         data = (data & ~(0xff << ((where & 3) << 3))) |
 132                                 (val << ((where & 3) << 3));
 133                 else if (size == 2)
 134                         data = (data & ~(0xffff << ((where & 3) << 3))) |
 135                                 (val << ((where & 3) << 3));
 136         }
 137
 138         if (bonito64_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
 139                                        &data))
 140                 return -1;
 141
 142         return PCIBIOS_SUCCESSFUL;
 143 }
 144
 145 struct pci_ops bonito64_pci_ops = {
 146         .read = bonito64_pcibios_read,
 147         .write = bonito64_pcibios_write
 148 };