Add the ability to reset the machine using the RESET_REG in ACPI's FADT table.

[linux-2.6-omap-h63xx.git] / drivers / acpi / reboot.c

diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c
new file mode 100644 (file)
index 0000000..a6b662c
--- /dev/null
+++ b/drivers/acpi/reboot.c
@@ -0,0 +1,50 @@
+
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <acpi/reboot.h>
+
+void acpi_reboot(void)
+{
+       struct acpi_generic_address *rr;
+       struct pci_bus *bus0;
+       u8 reset_value;
+       unsigned int devfn;
+
+       if (acpi_disabled)
+               return;
+
+       rr = &acpi_gbl_FADT.reset_register;
+
+       /* Is the reset register supported? */
+       if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER) ||
+           rr->bit_width != 8 || rr->bit_offset != 0)
+               return;
+
+       reset_value = acpi_gbl_FADT.reset_value;
+
+       /* The reset register can only exist in I/O, Memory or PCI config space
+        * on a device on bus 0. */
+       switch (rr->space_id) {
+       case ACPI_ADR_SPACE_PCI_CONFIG:
+               /* The reset register can only live on bus 0. */
+               bus0 = pci_find_bus(0, 0);
+               if (!bus0)
+                       return;
+               /* Form PCI device/function pair. */
+               devfn = PCI_DEVFN((rr->address >> 32) & 0xffff,
+                                 (rr->address >> 16) & 0xffff);
+               printk(KERN_DEBUG "Resetting with ACPI PCI RESET_REG.");
+               /* Write the value that resets us. */
+               pci_bus_write_config_byte(bus0, devfn,
+                               (rr->address & 0xffff), reset_value);
+               break;
+
+       case ACPI_ADR_SPACE_SYSTEM_MEMORY:
+       case ACPI_ADR_SPACE_SYSTEM_IO:
+               printk(KERN_DEBUG "ACPI MEMORY or I/O RESET_REG.\n");
+               acpi_hw_low_level_write(8, reset_value, rr);
+               break;
+       }
+       /* Wait ten seconds */
+       acpi_os_stall(10000000);
+}