ipmi: Create a platform device for a DMI-specified IPMI interface

Create a platform device for each IPMI device in the DMI table,
a separate kind of device for SSIF types and for KCS, BT, and
SMIC types.  This is so auto-loading IPMI devices will work
from just SMBIOS tables.

This also adds the ability to extract the slave address from
the SMBIOS tables, so that when the driver uses ACPI-specified
interfaces, it can still extract the slave address from SMBIOS.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Andy Lutomirski <luto@kernel.org>

4 files changed, 290 insertions, 0 deletions

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 90f3edffb067..f6fa056a52fc 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -5,6 +5,7 @@
 menuconfig IPMI_HANDLER
        tristate 'IPMI top-level message handler'
        depends on HAS_IOMEM
+       select IPMI_DMI_DECODE if DMI
        help
          This enables the central IPMI message handler, required for IPMI
          to work.
@@ -16,6 +17,9 @@ menuconfig IPMI_HANDLER
 
          If unsure, say N.
 
+config IPMI_DMI_DECODE
+       bool
+
 if IPMI_HANDLER
 
 config IPMI_PANIC_EVENT
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index 0d98cd91def1..eefb0b301e83 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -7,6 +7,7 @@ ipmi_si-y := ipmi_si_intf.o ipmi_kcs_sm.o ipmi_smic_sm.o ipmi_bt_sm.o
 obj-$(CONFIG_IPMI_HANDLER) += ipmi_msghandler.o
 obj-$(CONFIG_IPMI_DEVICE_INTERFACE) += ipmi_devintf.o
 obj-$(CONFIG_IPMI_SI) += ipmi_si.o
+obj-$(CONFIG_IPMI_DMI_DECODE) += ipmi_dmi.o
 obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
 obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
 obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
diff --git a/drivers/char/ipmi/ipmi_dmi.c b/drivers/char/ipmi/ipmi_dmi.c
new file mode 100644
index 000000000000..2a84401dea05
--- /dev/null
+++ b/drivers/char/ipmi/ipmi_dmi.c
@@ -0,0 +1,273 @@
+/*
+ * A hack to create a platform device from a DMI entry.  This will
+ * allow autoloading of the IPMI drive based on SMBIOS entries.
+ */
+
+#include <linux/ipmi.h>
+#include <linux/init.h>
+#include <linux/dmi.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include "ipmi_dmi.h"
+
+struct ipmi_dmi_info {
+        int type;
+        u32 flags;
+        unsigned long addr;
+        u8 slave_addr;
+        struct ipmi_dmi_info *next;
+};
+
+static struct ipmi_dmi_info *ipmi_dmi_infos;
+
+static int ipmi_dmi_nr __initdata;
+
+static void __init dmi_add_platform_ipmi(unsigned long base_addr,
+                                         u32 flags,
+                                         u8 slave_addr,
+                                         int irq,
+                                         int offset,
+                                         int type)
+{
+        struct platform_device *pdev;
+        struct resource r[4];
+        unsigned int num_r = 1, size;
+        struct property_entry p[4] = {
+                PROPERTY_ENTRY_U8("slave-addr", slave_addr),
+                PROPERTY_ENTRY_U8("ipmi-type", type),
+                PROPERTY_ENTRY_U16("i2c-addr", base_addr),
+                { }
+        };
+        char *name, *override;
+        int rv;
+        struct ipmi_dmi_info *info;
+
+        info = kmalloc(sizeof(*info), GFP_KERNEL);
+        if (!info) {
+                pr_warn("ipmi:dmi: Could not allocate dmi info\n");
+        } else {
+                info->type = type;
+                info->flags = flags;
+                info->addr = base_addr;
+                info->slave_addr = slave_addr;
+                info->next = ipmi_dmi_infos;
+                ipmi_dmi_infos = info;
+        }
+
+        name = "dmi-ipmi-si";
+        override = "ipmi_si";
+        switch (type) {
+        case IPMI_DMI_TYPE_SSIF:
+                name = "dmi-ipmi-ssif";
+                override = "ipmi_ssif";
+                offset = 1;
+                size = 1;
+                break;
+        case IPMI_DMI_TYPE_BT:
+                size = 3;
+                break;
+        case IPMI_DMI_TYPE_KCS:
+        case IPMI_DMI_TYPE_SMIC:
+                size = 2;
+                break;
+        default:
+                pr_err("ipmi:dmi: Invalid IPMI type: %d", type);
+                return;
+        }
+
+        pdev = platform_device_alloc(name, ipmi_dmi_nr);
+        if (!pdev) {
+                pr_err("ipmi:dmi: Error allocation IPMI platform device");
+                return;
+        }
+        pdev->driver_override = override;
+
+        if (type == IPMI_DMI_TYPE_SSIF)
+                goto add_properties;
+
+        memset(r, 0, sizeof(r));
+
+        r[0].start = base_addr;
+        r[0].end = r[0].start + offset - 1;
+        r[0].name = "IPMI Address 1";
+        r[0].flags = flags;
+
+        if (size > 1) {
+                r[1].start = r[0].start + offset;
+                r[1].end = r[1].start + offset - 1;
+                r[1].name = "IPMI Address 2";
+                r[1].flags = flags;
+                num_r++;
+        }
+
+        if (size > 2) {
+                r[2].start = r[1].start + offset;
+                r[2].end = r[2].start + offset - 1;
+                r[2].name = "IPMI Address 3";
+                r[2].flags = flags;
+                num_r++;
+        }
+
+        if (irq) {
+                r[num_r].start = irq;
+                r[num_r].end = irq;
+                r[num_r].name = "IPMI IRQ";
+                r[num_r].flags = IORESOURCE_IRQ;
+                num_r++;
+        }
+
+        rv = platform_device_add_resources(pdev, r, num_r);
+        if (rv) {
+                dev_err(&pdev->dev,
+                        "ipmi:dmi: Unable to add resources: %d\n", rv);
+                goto err;
+        }
+
+add_properties:
+        rv = platform_device_add_properties(pdev, p);
+        if (rv) {
+                dev_err(&pdev->dev,
+                        "ipmi:dmi: Unable to add properties: %d\n", rv);
+                goto err;
+        }
+
+        rv = platform_device_add(pdev);
+        if (rv) {
+                dev_err(&pdev->dev, "ipmi:dmi: Unable to add device: %d\n", rv);
+                goto err;
+        }
+
+        ipmi_dmi_nr++;
+        return;
+
+err:
+        platform_device_put(pdev);
+}
+
+/*
+ * Look up the slave address for a given interface.  This is here
+ * because ACPI doesn't have a slave address while SMBIOS does, but we
+ * prefer using ACPI so the ACPI code can use the IPMI namespace.
+ * This function allows an ACPI-specified IPMI device to look up the
+ * slave address from the DMI table.
+ */
+int ipmi_dmi_get_slave_addr(int type, u32 flags, unsigned long base_addr)
+{
+        struct ipmi_dmi_info *info = ipmi_dmi_infos;
+
+        while (info) {
+                if (info->type == type &&
+                    info->flags == flags &&
+                    info->addr == base_addr)
+                        return info->slave_addr;
+                info = info->next;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(ipmi_dmi_get_slave_addr);
+
+#define DMI_IPMI_MIN_LENGTH     0x10
+#define DMI_IPMI_VER2_LENGTH    0x12
+#define DMI_IPMI_TYPE           4
+#define DMI_IPMI_SLAVEADDR      6
+#define DMI_IPMI_ADDR           8
+#define DMI_IPMI_ACCESS         0x10
+#define DMI_IPMI_IRQ            0x11
+#define DMI_IPMI_IO_MASK        0xfffe
+
+static void __init dmi_decode_ipmi(const struct dmi_header *dm)
+{
+        const u8        *data = (const u8 *) dm;
+        u32             flags = IORESOURCE_IO;
+        unsigned long   base_addr;
+        u8              len = dm->length;
+        u8              slave_addr;
+        int             irq = 0, offset;
+        int             type;
+
+        if (len < DMI_IPMI_MIN_LENGTH)
+                return;
+
+        type = data[DMI_IPMI_TYPE];
+        slave_addr = data[DMI_IPMI_SLAVEADDR];
+
+        memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));
+        if (len >= DMI_IPMI_VER2_LENGTH) {
+                if (type == IPMI_DMI_TYPE_SSIF) {
+                        offset = 0;
+                        flags = 0;
+                        base_addr = data[DMI_IPMI_ADDR] >> 1;
+                        if (base_addr == 0) {
+                                /*
+                                 * Some broken systems put the I2C address in
+                                 * the slave address field.  We try to
+                                 * accommodate them here.
+                                 */
+                                base_addr = data[DMI_IPMI_SLAVEADDR] >> 1;
+                                slave_addr = 0;
+                        }
+                } else {
+                        if (base_addr & 1) {
+                                /* I/O */
+                                base_addr &= DMI_IPMI_IO_MASK;
+                        } else {
+                                /* Memory */
+                                flags = IORESOURCE_MEM;
+                        }
+
+                        /*
+                         * If bit 4 of byte 0x10 is set, then the lsb
+                         * for the address is odd.
+                         */
+                        base_addr |= (data[DMI_IPMI_ACCESS] >> 4) & 1;
+
+                        irq = data[DMI_IPMI_IRQ];
+
+                        /*
+                         * The top two bits of byte 0x10 hold the
+                         * register spacing.
+                         */
+                        switch ((data[DMI_IPMI_ACCESS] >> 6) & 3) {
+                        case 0: /* Byte boundaries */
+                                offset = 1;
+                                break;
+                        case 1: /* 32-bit boundaries */
+                                offset = 4;
+                                break;
+                        case 2: /* 16-byte boundaries */
+                                offset = 16;
+                                break;
+                        default:
+                                pr_err("ipmi:dmi: Invalid offset: 0");
+                                return;
+                        }
+                }
+        } else {
+                /* Old DMI spec. */
+                /*
+                 * Note that technically, the lower bit of the base
+                 * address should be 1 if the address is I/O and 0 if
+                 * the address is in memory.  So many systems get that
+                 * wrong (and all that I have seen are I/O) so we just
+                 * ignore that bit and assume I/O.  Systems that use
+                 * memory should use the newer spec, anyway.
+                 */
+                base_addr = base_addr & DMI_IPMI_IO_MASK;
+                offset = 1;
+        }
+
+        dmi_add_platform_ipmi(base_addr, flags, slave_addr, irq,
+                              offset, type);
+}
+
+static int __init scan_for_dmi_ipmi(void)
+{
+        const struct dmi_device *dev = NULL;
+
+        while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev)))
+                dmi_decode_ipmi((const struct dmi_header *) dev->device_data);
+
+        return 0;
+}
+subsys_initcall(scan_for_dmi_ipmi);
diff --git a/drivers/char/ipmi/ipmi_dmi.h b/drivers/char/ipmi/ipmi_dmi.h
new file mode 100644
index 000000000000..0a1afe5ceb1e
--- /dev/null
+++ b/drivers/char/ipmi/ipmi_dmi.h
@@ -0,0 +1,12 @@
+/*
+ * DMI defines for use by IPMI
+ */
+
+#define IPMI_DMI_TYPE_KCS       0x01
+#define IPMI_DMI_TYPE_SMIC      0x02
+#define IPMI_DMI_TYPE_BT        0x03
+#define IPMI_DMI_TYPE_SSIF      0x04
+
+#ifdef CONFIG_IPMI_DMI_DECODE
+int ipmi_dmi_get_slave_addr(int type, u32 flags, unsigned long base_addr);
+#endif