uboot/drivers/misc/p2sb_emul.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * PCI emulation device for an x86 Primary-to-Sideband bus
   4 *
   5 * Copyright 2019 Google LLC
   6 * Written by Simon Glass <sjg@chromium.org>
   7 */
   8
   9#define LOG_CATEGORY UCLASS_MISC
  10#define LOG_DEBUG
  11
  12#include <common.h>
  13#include <axi.h>
  14#include <dm.h>
  15#include <log.h>
  16#include <pci.h>
  17#include <asm/test.h>
  18#include <p2sb.h>
  19
  20/**
  21 * struct p2sb_emul_platdata - platform data for this device
  22 *
  23 * @command:    Current PCI command value
  24 * @bar:        Current base address values
  25 */
  26struct p2sb_emul_platdata {
  27        u16 command;
  28        u32 bar[6];
  29};
  30
  31enum {
  32        /* This emulator supports 16 different devices */
  33        MEMMAP_SIZE     = 16 << PCR_PORTID_SHIFT,
  34};
  35
  36static struct pci_bar {
  37        int type;
  38        u32 size;
  39} barinfo[] = {
  40        { PCI_BASE_ADDRESS_MEM_TYPE_32, MEMMAP_SIZE },
  41        { 0, 0 },
  42        { 0, 0 },
  43        { 0, 0 },
  44        { 0, 0 },
  45        { 0, 0 },
  46};
  47
  48struct p2sb_emul_priv {
  49        u8 regs[16];
  50};
  51
  52static int sandbox_p2sb_emul_read_config(const struct udevice *emul,
  53                                         uint offset, ulong *valuep,
  54                                         enum pci_size_t size)
  55{
  56        struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
  57
  58        switch (offset) {
  59        case PCI_COMMAND:
  60                *valuep = plat->command;
  61                break;
  62        case PCI_HEADER_TYPE:
  63                *valuep = PCI_HEADER_TYPE_NORMAL;
  64                break;
  65        case PCI_VENDOR_ID:
  66                *valuep = SANDBOX_PCI_VENDOR_ID;
  67                break;
  68        case PCI_DEVICE_ID:
  69                *valuep = SANDBOX_PCI_P2SB_EMUL_ID;
  70                break;
  71        case PCI_CLASS_DEVICE:
  72                if (size == PCI_SIZE_8) {
  73                        *valuep = SANDBOX_PCI_CLASS_SUB_CODE;
  74                } else {
  75                        *valuep = (SANDBOX_PCI_CLASS_CODE << 8) |
  76                                        SANDBOX_PCI_CLASS_SUB_CODE;
  77                }
  78                break;
  79        case PCI_CLASS_CODE:
  80                *valuep = SANDBOX_PCI_CLASS_CODE;
  81                break;
  82        case PCI_BASE_ADDRESS_0:
  83        case PCI_BASE_ADDRESS_1:
  84        case PCI_BASE_ADDRESS_2:
  85        case PCI_BASE_ADDRESS_3:
  86        case PCI_BASE_ADDRESS_4:
  87        case PCI_BASE_ADDRESS_5: {
  88                int barnum;
  89                u32 *bar;
  90
  91                barnum = pci_offset_to_barnum(offset);
  92                bar = &plat->bar[barnum];
  93
  94                *valuep = sandbox_pci_read_bar(*bar, barinfo[barnum].type,
  95                                               barinfo[barnum].size);
  96                break;
  97        }
  98        case PCI_CAPABILITY_LIST:
  99                *valuep = PCI_CAP_ID_PM_OFFSET;
 100                break;
 101        }
 102
 103        return 0;
 104}
 105
 106static int sandbox_p2sb_emul_write_config(struct udevice *emul, uint offset,
 107                                          ulong value, enum pci_size_t size)
 108{
 109        struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
 110
 111        switch (offset) {
 112        case PCI_COMMAND:
 113                plat->command = value;
 114                break;
 115        case PCI_BASE_ADDRESS_0:
 116        case PCI_BASE_ADDRESS_1: {
 117                int barnum;
 118                u32 *bar;
 119
 120                barnum = pci_offset_to_barnum(offset);
 121                bar = &plat->bar[barnum];
 122
 123                log_debug("w bar %d=%lx\n", barnum, value);
 124                *bar = value;
 125                /* space indicator (bit#0) is read-only */
 126                *bar |= barinfo[barnum].type;
 127                break;
 128        }
 129        }
 130
 131        return 0;
 132}
 133
 134static int sandbox_p2sb_emul_find_bar(struct udevice *emul, unsigned int addr,
 135                                      int *barnump, unsigned int *offsetp)
 136{
 137        struct p2sb_emul_platdata *plat = dev_get_platdata(emul);
 138        int barnum;
 139
 140        for (barnum = 0; barnum < ARRAY_SIZE(barinfo); barnum++) {
 141                unsigned int size = barinfo[barnum].size;
 142                u32 base = plat->bar[barnum] & ~PCI_BASE_ADDRESS_SPACE;
 143
 144                if (addr >= base && addr < base + size) {
 145                        *barnump = barnum;
 146                        *offsetp = addr - base;
 147                        return 0;
 148                }
 149        }
 150        *barnump = -1;
 151
 152        return -ENOENT;
 153}
 154
 155static int sandbox_p2sb_emul_read_io(struct udevice *dev, unsigned int addr,
 156                                     ulong *valuep, enum pci_size_t size)
 157{
 158        unsigned int offset;
 159        int barnum;
 160        int ret;
 161
 162        ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
 163        if (ret)
 164                return ret;
 165
 166        if (barnum == 4)
 167                *valuep = offset;
 168        else if (barnum == 0)
 169                *valuep = offset;
 170
 171        return 0;
 172}
 173
 174static int sandbox_p2sb_emul_write_io(struct udevice *dev, unsigned int addr,
 175                                      ulong value, enum pci_size_t size)
 176{
 177        unsigned int offset;
 178        int barnum;
 179        int ret;
 180
 181        ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
 182        if (ret)
 183                return ret;
 184
 185        return 0;
 186}
 187
 188static int find_p2sb_channel(struct udevice *emul, uint offset,
 189                             struct udevice **devp)
 190{
 191        uint pid = offset >> PCR_PORTID_SHIFT;
 192        struct udevice *p2sb, *dev;
 193        int ret;
 194
 195        ret = sandbox_pci_get_client(emul, &p2sb);
 196        if (ret)
 197                return log_msg_ret("No client", ret);
 198
 199        device_foreach_child(dev, p2sb) {
 200                struct p2sb_child_platdata *pplat =
 201                         dev_get_parent_platdata(dev);
 202
 203                log_debug("   - child %s, pid %d, want %d\n", dev->name,
 204                          pplat->pid, pid);
 205                if (pid == pplat->pid) {
 206                        *devp = dev;
 207                        return 0;
 208                }
 209        }
 210
 211        return -ENOENT;
 212}
 213
 214static int sandbox_p2sb_emul_map_physmem(struct udevice *dev,
 215                                         phys_addr_t addr, unsigned long *lenp,
 216                                         void **ptrp)
 217{
 218        struct p2sb_emul_priv *priv = dev_get_priv(dev);
 219        struct udevice *child = NULL;  /* Silence compiler warning */
 220        unsigned int offset;
 221        int barnum;
 222        int ret;
 223
 224        log_debug("map %x: ", (uint)addr);
 225        ret = sandbox_p2sb_emul_find_bar(dev, addr, &barnum, &offset);
 226        if (ret)
 227                return log_msg_ret("Cannot find bar", ret);
 228        log_debug("bar %d, offset %x\n", barnum, offset);
 229
 230        if (barnum != 0)
 231                return log_msg_ret("Unknown BAR", -EINVAL);
 232
 233        ret = find_p2sb_channel(dev, offset, &child);
 234        if (ret)
 235                return log_msg_ret("Cannot find channel", ret);
 236
 237        offset &= ((1 << PCR_PORTID_SHIFT) - 1);
 238        ret = axi_read(child, offset, priv->regs, AXI_SIZE_32);
 239        if (ret)
 240                return log_msg_ret("Child read failed", ret);
 241        *ptrp = priv->regs + (offset & 3);
 242        *lenp = 4;
 243
 244        return 0;
 245}
 246
 247static struct dm_pci_emul_ops sandbox_p2sb_emul_emul_ops = {
 248        .read_config = sandbox_p2sb_emul_read_config,
 249        .write_config = sandbox_p2sb_emul_write_config,
 250        .read_io = sandbox_p2sb_emul_read_io,
 251        .write_io = sandbox_p2sb_emul_write_io,
 252        .map_physmem = sandbox_p2sb_emul_map_physmem,
 253};
 254
 255static const struct udevice_id sandbox_p2sb_emul_ids[] = {
 256        { .compatible = "sandbox,p2sb-emul" },
 257        { }
 258};
 259
 260U_BOOT_DRIVER(sandbox_p2sb_emul_emul) = {
 261        .name           = "sandbox_p2sb_emul_emul",
 262        .id             = UCLASS_PCI_EMUL,
 263        .of_match       = sandbox_p2sb_emul_ids,
 264        .ops            = &sandbox_p2sb_emul_emul_ops,
 265        .priv_auto_alloc_size = sizeof(struct p2sb_emul_priv),
 266        .platdata_auto_alloc_size = sizeof(struct p2sb_emul_platdata),
 267};
 268
 269static struct pci_device_id sandbox_p2sb_emul_supported[] = {
 270        { PCI_VDEVICE(SANDBOX, SANDBOX_PCI_PMC_EMUL_ID) },
 271        {},
 272};
 273
 274U_BOOT_PCI_DEVICE(sandbox_p2sb_emul_emul, sandbox_p2sb_emul_supported);
 275