1 // SPDX-License-Identifier: GPL-2.0+
3 * A hack to create a platform device from a DMI entry. This will
4 * allow autoloading of the IPMI drive based on SMBIOS entries.
7 #define pr_fmt(fmt) "%s" fmt, "ipmi:dmi: "
10 #include <linux/ipmi.h>
11 #include <linux/init.h>
12 #include <linux/dmi.h>
13 #include <linux/platform_device.h>
14 #include <linux/property.h>
15 #include "ipmi_si_sm.h"
18 #define IPMI_DMI_TYPE_KCS 0x01
19 #define IPMI_DMI_TYPE_SMIC 0x02
20 #define IPMI_DMI_TYPE_BT 0x03
21 #define IPMI_DMI_TYPE_SSIF 0x04
23 struct ipmi_dmi_info {
28 struct ipmi_dmi_info *next;
31 static struct ipmi_dmi_info *ipmi_dmi_infos;
33 static int ipmi_dmi_nr __initdata;
35 static void __init dmi_add_platform_ipmi(unsigned long base_addr,
42 struct platform_device *pdev;
44 unsigned int num_r = 1, size;
45 struct property_entry p[5];
46 unsigned int pidx = 0;
50 struct ipmi_dmi_info *info;
52 memset(p, 0, sizeof(p));
56 case IPMI_DMI_TYPE_SSIF:
57 name = "dmi-ipmi-ssif";
60 si_type = SI_TYPE_INVALID;
62 case IPMI_DMI_TYPE_BT:
66 case IPMI_DMI_TYPE_KCS:
70 case IPMI_DMI_TYPE_SMIC:
75 pr_err("Invalid IPMI type: %d\n", type);
79 if (si_type != SI_TYPE_INVALID)
80 p[pidx++] = PROPERTY_ENTRY_U8("ipmi-type", si_type);
82 p[pidx++] = PROPERTY_ENTRY_U8("slave-addr", slave_addr);
83 p[pidx++] = PROPERTY_ENTRY_U8("addr-source", SI_SMBIOS);
85 info = kmalloc(sizeof(*info), GFP_KERNEL);
87 pr_warn("Could not allocate dmi info\n");
89 info->si_type = si_type;
91 info->addr = base_addr;
92 info->slave_addr = slave_addr;
93 info->next = ipmi_dmi_infos;
94 ipmi_dmi_infos = info;
97 pdev = platform_device_alloc(name, ipmi_dmi_nr);
99 pr_err("Error allocation IPMI platform device\n");
103 if (type == IPMI_DMI_TYPE_SSIF) {
104 p[pidx++] = PROPERTY_ENTRY_U16("i2c-addr", base_addr);
108 memset(r, 0, sizeof(r));
110 r[0].start = base_addr;
111 r[0].end = r[0].start + offset - 1;
112 r[0].name = "IPMI Address 1";
116 r[1].start = r[0].start + offset;
117 r[1].end = r[1].start + offset - 1;
118 r[1].name = "IPMI Address 2";
124 r[2].start = r[1].start + offset;
125 r[2].end = r[2].start + offset - 1;
126 r[2].name = "IPMI Address 3";
132 r[num_r].start = irq;
134 r[num_r].name = "IPMI IRQ";
135 r[num_r].flags = IORESOURCE_IRQ;
139 rv = platform_device_add_resources(pdev, r, num_r);
141 dev_err(&pdev->dev, "Unable to add resources: %d\n", rv);
146 rv = platform_device_add_properties(pdev, p);
148 dev_err(&pdev->dev, "Unable to add properties: %d\n", rv);
152 rv = platform_device_add(pdev);
154 dev_err(&pdev->dev, "Unable to add device: %d\n", rv);
162 platform_device_put(pdev);
166 * Look up the slave address for a given interface. This is here
167 * because ACPI doesn't have a slave address while SMBIOS does, but we
168 * prefer using ACPI so the ACPI code can use the IPMI namespace.
169 * This function allows an ACPI-specified IPMI device to look up the
170 * slave address from the DMI table.
172 int ipmi_dmi_get_slave_addr(enum si_type si_type, u32 flags,
173 unsigned long base_addr)
175 struct ipmi_dmi_info *info = ipmi_dmi_infos;
178 if (info->si_type == si_type &&
179 info->flags == flags &&
180 info->addr == base_addr)
181 return info->slave_addr;
187 EXPORT_SYMBOL(ipmi_dmi_get_slave_addr);
189 #define DMI_IPMI_MIN_LENGTH 0x10
190 #define DMI_IPMI_VER2_LENGTH 0x12
191 #define DMI_IPMI_TYPE 4
192 #define DMI_IPMI_SLAVEADDR 6
193 #define DMI_IPMI_ADDR 8
194 #define DMI_IPMI_ACCESS 0x10
195 #define DMI_IPMI_IRQ 0x11
196 #define DMI_IPMI_IO_MASK 0xfffe
198 static void __init dmi_decode_ipmi(const struct dmi_header *dm)
200 const u8 *data = (const u8 *) dm;
201 u32 flags = IORESOURCE_IO;
202 unsigned long base_addr;
208 if (len < DMI_IPMI_MIN_LENGTH)
211 type = data[DMI_IPMI_TYPE];
212 slave_addr = data[DMI_IPMI_SLAVEADDR];
214 memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));
216 pr_err("Base address is zero, assuming no IPMI interface\n");
219 if (len >= DMI_IPMI_VER2_LENGTH) {
220 if (type == IPMI_DMI_TYPE_SSIF) {
223 base_addr = data[DMI_IPMI_ADDR] >> 1;
224 if (base_addr == 0) {
226 * Some broken systems put the I2C address in
227 * the slave address field. We try to
228 * accommodate them here.
230 base_addr = data[DMI_IPMI_SLAVEADDR] >> 1;
236 base_addr &= DMI_IPMI_IO_MASK;
239 flags = IORESOURCE_MEM;
243 * If bit 4 of byte 0x10 is set, then the lsb
244 * for the address is odd.
246 base_addr |= (data[DMI_IPMI_ACCESS] >> 4) & 1;
248 irq = data[DMI_IPMI_IRQ];
251 * The top two bits of byte 0x10 hold the
254 switch ((data[DMI_IPMI_ACCESS] >> 6) & 3) {
255 case 0: /* Byte boundaries */
258 case 1: /* 32-bit boundaries */
261 case 2: /* 16-byte boundaries */
265 pr_err("Invalid offset: 0\n");
272 * Note that technically, the lower bit of the base
273 * address should be 1 if the address is I/O and 0 if
274 * the address is in memory. So many systems get that
275 * wrong (and all that I have seen are I/O) so we just
276 * ignore that bit and assume I/O. Systems that use
277 * memory should use the newer spec, anyway.
279 base_addr = base_addr & DMI_IPMI_IO_MASK;
283 dmi_add_platform_ipmi(base_addr, flags, slave_addr, irq,
287 static int __init scan_for_dmi_ipmi(void)
289 const struct dmi_device *dev = NULL;
291 while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
292 dmi_decode_ipmi((const struct dmi_header *) dev->device_data);
296 subsys_initcall(scan_for_dmi_ipmi);