drivers/char/ipmi/ipmi_dmi.c

   1 /*
   2  * A hack to create a platform device from a DMI entry.  This will
   3  * allow autoloading of the IPMI drive based on SMBIOS entries.
   4  */
   5
   6 #include <linux/ipmi.h>
   7 #include <linux/init.h>
   8 #include <linux/dmi.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/property.h>
  11 #include "ipmi_dmi.h"
  12
  13 struct ipmi_dmi_info {
  14         int type;
  15         u32 flags;
  16         unsigned long addr;
  17         u8 slave_addr;
  18         struct ipmi_dmi_info *next;
  19 };
  20
  21 static struct ipmi_dmi_info *ipmi_dmi_infos;
  22
  23 static int ipmi_dmi_nr __initdata;
  24
  25 static void __init dmi_add_platform_ipmi(unsigned long base_addr,
  26                                          u32 flags,
  27                                          u8 slave_addr,
  28                                          int irq,
  29                                          int offset,
  30                                          int type)
  31 {
  32         struct platform_device *pdev;
  33         struct resource r[4];
  34         unsigned int num_r = 1, size;
  35         struct property_entry p[4] = {
  36                 PROPERTY_ENTRY_U8("slave-addr", slave_addr),
  37                 PROPERTY_ENTRY_U8("ipmi-type", type),
  38                 PROPERTY_ENTRY_U16("i2c-addr", base_addr),
  39                 { }
  40         };
  41         char *name, *override;
  42         int rv;
  43         struct ipmi_dmi_info *info;
  44
  45         info = kmalloc(sizeof(*info), GFP_KERNEL);
  46         if (!info) {
  47                 pr_warn("ipmi:dmi: Could not allocate dmi info\n");
  48         } else {
  49                 info->type = type;
  50                 info->flags = flags;
  51                 info->addr = base_addr;
  52                 info->slave_addr = slave_addr;
  53                 info->next = ipmi_dmi_infos;
  54                 ipmi_dmi_infos = info;
  55         }
  56
  57         name = "dmi-ipmi-si";
  58         override = "ipmi_si";
  59         switch (type) {
  60         case IPMI_DMI_TYPE_SSIF:
  61                 name = "dmi-ipmi-ssif";
  62                 override = "ipmi_ssif";
  63                 offset = 1;
  64                 size = 1;
  65                 break;
  66         case IPMI_DMI_TYPE_BT:
  67                 size = 3;
  68                 break;
  69         case IPMI_DMI_TYPE_KCS:
  70         case IPMI_DMI_TYPE_SMIC:
  71                 size = 2;
  72                 break;
  73         default:
  74                 pr_err("ipmi:dmi: Invalid IPMI type: %d", type);
  75                 return;
  76         }
  77
  78         pdev = platform_device_alloc(name, ipmi_dmi_nr);
  79         if (!pdev) {
  80                 pr_err("ipmi:dmi: Error allocation IPMI platform device");
  81                 return;
  82         }
  83         pdev->driver_override = override;
  84
  85         if (type == IPMI_DMI_TYPE_SSIF)
  86                 goto add_properties;
  87
  88         memset(r, 0, sizeof(r));
  89
  90         r[0].start = base_addr;
  91         r[0].end = r[0].start + offset - 1;
  92         r[0].name = "IPMI Address 1";
  93         r[0].flags = flags;
  94
  95         if (size > 1) {
  96                 r[1].start = r[0].start + offset;
  97                 r[1].end = r[1].start + offset - 1;
  98                 r[1].name = "IPMI Address 2";
  99                 r[1].flags = flags;
 100                 num_r++;
 101         }
 102
 103         if (size > 2) {
 104                 r[2].start = r[1].start + offset;
 105                 r[2].end = r[2].start + offset - 1;
 106                 r[2].name = "IPMI Address 3";
 107                 r[2].flags = flags;
 108                 num_r++;
 109         }
 110
 111         if (irq) {
 112                 r[num_r].start = irq;
 113                 r[num_r].end = irq;
 114                 r[num_r].name = "IPMI IRQ";
 115                 r[num_r].flags = IORESOURCE_IRQ;
 116                 num_r++;
 117         }
 118
 119         rv = platform_device_add_resources(pdev, r, num_r);
 120         if (rv) {
 121                 dev_err(&pdev->dev,
 122                         "ipmi:dmi: Unable to add resources: %d\n", rv);
 123                 goto err;
 124         }
 125
 126 add_properties:
 127         rv = platform_device_add_properties(pdev, p);
 128         if (rv) {
 129                 dev_err(&pdev->dev,
 130                         "ipmi:dmi: Unable to add properties: %d\n", rv);
 131                 goto err;
 132         }
 133
 134         rv = platform_device_add(pdev);
 135         if (rv) {
 136                 dev_err(&pdev->dev, "ipmi:dmi: Unable to add device: %d\n", rv);
 137                 goto err;
 138         }
 139
 140         ipmi_dmi_nr++;
 141         return;
 142
 143 err:
 144         platform_device_put(pdev);
 145 }
 146
 147 /*
 148  * Look up the slave address for a given interface.  This is here
 149  * because ACPI doesn't have a slave address while SMBIOS does, but we
 150  * prefer using ACPI so the ACPI code can use the IPMI namespace.
 151  * This function allows an ACPI-specified IPMI device to look up the
 152  * slave address from the DMI table.
 153  */
 154 int ipmi_dmi_get_slave_addr(int type, u32 flags, unsigned long base_addr)
 155 {
 156         struct ipmi_dmi_info *info = ipmi_dmi_infos;
 157
 158         while (info) {
 159                 if (info->type == type &&
 160                     info->flags == flags &&
 161                     info->addr == base_addr)
 162                         return info->slave_addr;
 163                 info = info->next;
 164         }
 165
 166         return 0;
 167 }
 168 EXPORT_SYMBOL(ipmi_dmi_get_slave_addr);
 169
 170 #define DMI_IPMI_MIN_LENGTH     0x10
 171 #define DMI_IPMI_VER2_LENGTH    0x12
 172 #define DMI_IPMI_TYPE           4
 173 #define DMI_IPMI_SLAVEADDR      6
 174 #define DMI_IPMI_ADDR           8
 175 #define DMI_IPMI_ACCESS         0x10
 176 #define DMI_IPMI_IRQ            0x11
 177 #define DMI_IPMI_IO_MASK        0xfffe
 178
 179 static void __init dmi_decode_ipmi(const struct dmi_header *dm)
 180 {
 181         const u8        *data = (const u8 *) dm;
 182         u32             flags = IORESOURCE_IO;
 183         unsigned long   base_addr;
 184         u8              len = dm->length;
 185         u8              slave_addr;
 186         int             irq = 0, offset;
 187         int             type;
 188
 189         if (len < DMI_IPMI_MIN_LENGTH)
 190                 return;
 191
 192         type = data[DMI_IPMI_TYPE];
 193         slave_addr = data[DMI_IPMI_SLAVEADDR];
 194
 195         memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));
 196         if (len >= DMI_IPMI_VER2_LENGTH) {
 197                 if (type == IPMI_DMI_TYPE_SSIF) {
 198                         offset = 0;
 199                         flags = 0;
 200                         base_addr = data[DMI_IPMI_ADDR] >> 1;
 201                         if (base_addr == 0) {
 202                                 /*
 203                                  * Some broken systems put the I2C address in
 204                                  * the slave address field.  We try to
 205                                  * accommodate them here.
 206                                  */
 207                                 base_addr = data[DMI_IPMI_SLAVEADDR] >> 1;
 208                                 slave_addr = 0;
 209                         }
 210                 } else {
 211                         if (base_addr & 1) {
 212                                 /* I/O */
 213                                 base_addr &= DMI_IPMI_IO_MASK;
 214                         } else {
 215                                 /* Memory */
 216                                 flags = IORESOURCE_MEM;
 217                         }
 218
 219                         /*
 220                          * If bit 4 of byte 0x10 is set, then the lsb
 221                          * for the address is odd.
 222                          */
 223                         base_addr |= (data[DMI_IPMI_ACCESS] >> 4) & 1;
 224
 225                         irq = data[DMI_IPMI_IRQ];
 226
 227                         /*
 228                          * The top two bits of byte 0x10 hold the
 229                          * register spacing.
 230                          */
 231                         switch ((data[DMI_IPMI_ACCESS] >> 6) & 3) {
 232                         case 0: /* Byte boundaries */
 233                                 offset = 1;
 234                                 break;
 235                         case 1: /* 32-bit boundaries */
 236                                 offset = 4;
 237                                 break;
 238                         case 2: /* 16-byte boundaries */
 239                                 offset = 16;
 240                                 break;
 241                         default:
 242                                 pr_err("ipmi:dmi: Invalid offset: 0");
 243                                 return;
 244                         }
 245                 }
 246         } else {
 247                 /* Old DMI spec. */
 248                 /*
 249                  * Note that technically, the lower bit of the base
 250                  * address should be 1 if the address is I/O and 0 if
 251                  * the address is in memory.  So many systems get that
 252                  * wrong (and all that I have seen are I/O) so we just
 253                  * ignore that bit and assume I/O.  Systems that use
 254                  * memory should use the newer spec, anyway.
 255                  */
 256                 base_addr = base_addr & DMI_IPMI_IO_MASK;
 257                 offset = 1;
 258         }
 259
 260         dmi_add_platform_ipmi(base_addr, flags, slave_addr, irq,
 261                               offset, type);
 262 }
 263
 264 static int __init scan_for_dmi_ipmi(void)
 265 {
 266         const struct dmi_device *dev = NULL;
 267
 268         while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
 269                 dmi_decode_ipmi((const struct dmi_header *) dev->device_data);
 270
 271         return 0;
 272 }
 273 subsys_initcall(scan_for_dmi_ipmi);