drivers/pci/pci_gt64120.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
   4  *
   5  * Based on the Linux implementation.
   6  *   Copyright (C) 1999, 2000, 2004  MIPS Technologies, Inc.
   7  *   Authors: Carsten Langgaard <carstenl@mips.com>
   8  *            Maciej W. Rozycki <macro@mips.com>
   9  */
  10
  11 #include <common.h>
  12 #include <gt64120.h>
  13 #include <pci.h>
  14 #include <pci_gt64120.h>
  15
  16 #include <asm/io.h>
  17
  18 #define PCI_ACCESS_READ  0
  19 #define PCI_ACCESS_WRITE 1
  20
  21 struct gt64120_regs {
  22         u8      unused_000[0xc18];
  23         u32     intrcause;
  24         u8      unused_c1c[0x0dc];
  25         u32     pci0_cfgaddr;
  26         u32     pci0_cfgdata;
  27 };
  28
  29 struct gt64120_pci_controller {
  30         struct pci_controller hose;
  31         struct gt64120_regs *regs;
  32 };
  33
  34 static inline struct gt64120_pci_controller *
  35 hose_to_gt64120(struct pci_controller *hose)
  36 {
  37         return container_of(hose, struct gt64120_pci_controller, hose);
  38 }
  39
  40 #define GT_INTRCAUSE_ABORT_BITS \
  41                 (GT_INTRCAUSE_MASABORT0_BIT | GT_INTRCAUSE_TARABORT0_BIT)
  42
  43 static int gt_config_access(struct gt64120_pci_controller *gt,
  44                             unsigned char access_type, pci_dev_t bdf,
  45                             int where, u32 *data)
  46 {
  47         unsigned int bus = PCI_BUS(bdf);
  48         unsigned int dev = PCI_DEV(bdf);
  49         unsigned int devfn = PCI_DEV(bdf) << 3 | PCI_FUNC(bdf);
  50         u32 intr;
  51         u32 addr;
  52         u32 val;
  53
  54         if (bus == 0 && dev >= 31) {
  55                 /* Because of a bug in the galileo (for slot 31). */
  56                 return -1;
  57         }
  58
  59         if (access_type == PCI_ACCESS_WRITE)
  60                 debug("PCI WR %02x:%02x.%x reg:%02d data:%08x\n",
  61                       PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf), where, *data);
  62
  63         /* Clear cause register bits */
  64         writel(~GT_INTRCAUSE_ABORT_BITS, &gt->regs->intrcause);
  65
  66         addr = GT_PCI0_CFGADDR_CONFIGEN_BIT;
  67         addr |= bus << GT_PCI0_CFGADDR_BUSNUM_SHF;
  68         addr |= devfn << GT_PCI0_CFGADDR_FUNCTNUM_SHF;
  69         addr |= (where / 4) << GT_PCI0_CFGADDR_REGNUM_SHF;
  70
  71         /* Setup address */
  72         writel(addr, &gt->regs->pci0_cfgaddr);
  73
  74         if (access_type == PCI_ACCESS_WRITE) {
  75                 if (bus == 0 && dev == 0) {
  76                         /*
  77                          * The Galileo system controller is acting
  78                          * differently than other devices.
  79                          */
  80                         val = *data;
  81                 } else {
  82                         val = cpu_to_le32(*data);
  83                 }
  84
  85                 writel(val, &gt->regs->pci0_cfgdata);
  86         } else {
  87                 val = readl(&gt->regs->pci0_cfgdata);
  88
  89                 if (bus == 0 && dev == 0) {
  90                         /*
  91                          * The Galileo system controller is acting
  92                          * differently than other devices.
  93                          */
  94                         *data = val;
  95                 } else {
  96                         *data = le32_to_cpu(val);
  97                 }
  98         }
  99
 100         /* Check for master or target abort */
 101         intr = readl(&gt->regs->intrcause);
 102         if (intr & GT_INTRCAUSE_ABORT_BITS) {
 103                 /* Error occurred, clear abort bits */
 104                 writel(~GT_INTRCAUSE_ABORT_BITS, &gt->regs->intrcause);
 105                 return -1;
 106         }
 107
 108         if (access_type == PCI_ACCESS_READ)
 109                 debug("PCI RD %02x:%02x.%x reg:%02d data:%08x\n",
 110                       PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf), where, *data);
 111
 112         return 0;
 113 }
 114
 115 static int gt_read_config_dword(struct pci_controller *hose, pci_dev_t dev,
 116                                 int where, u32 *value)
 117 {
 118         struct gt64120_pci_controller *gt = hose_to_gt64120(hose);
 119
 120         *value = 0xffffffff;
 121         return gt_config_access(gt, PCI_ACCESS_READ, dev, where, value);
 122 }
 123
 124 static int gt_write_config_dword(struct pci_controller *hose, pci_dev_t dev,
 125                                  int where, u32 value)
 126 {
 127         struct gt64120_pci_controller *gt = hose_to_gt64120(hose);
 128         u32 data = value;
 129
 130         return gt_config_access(gt, PCI_ACCESS_WRITE, dev, where, &data);
 131 }
 132
 133 void gt64120_pci_init(void *regs, unsigned long sys_bus, unsigned long sys_phys,
 134                      unsigned long sys_size, unsigned long mem_bus,
 135                      unsigned long mem_phys, unsigned long mem_size,
 136                      unsigned long io_bus, unsigned long io_phys,
 137                      unsigned long io_size)
 138 {
 139         static struct gt64120_pci_controller global_gt;
 140         struct gt64120_pci_controller *gt;
 141         struct pci_controller *hose;
 142
 143         gt = &global_gt;
 144         gt->regs = regs;
 145
 146         hose = &gt->hose;
 147
 148         hose->first_busno = 0;
 149         hose->last_busno = 0;
 150
 151         /* System memory space */
 152         pci_set_region(&hose->regions[0], sys_bus, sys_phys, sys_size,
 153                        PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);
 154
 155         /* PCI memory space */
 156         pci_set_region(&hose->regions[1], mem_bus, mem_phys, mem_size,
 157                        PCI_REGION_MEM);
 158
 159         /* PCI I/O space */
 160         pci_set_region(&hose->regions[2], io_bus, io_phys, io_size,
 161                        PCI_REGION_IO);
 162
 163         hose->region_count = 3;
 164
 165         pci_set_ops(hose,
 166                     pci_hose_read_config_byte_via_dword,
 167                     pci_hose_read_config_word_via_dword,
 168                     gt_read_config_dword,
 169                     pci_hose_write_config_byte_via_dword,
 170                     pci_hose_write_config_word_via_dword,
 171                     gt_write_config_dword);
 172
 173         pci_register_hose(hose);
 174         hose->last_busno = pci_hose_scan(hose);
 175 }