x86: enable hpet=force for AMD SB400

Add quirk to allow forced usage of HPET on ATI SB400.
I stumbled over machines where HPET is enabled but not reported
by BIOS. This patch configures the HPET base address and makes
it known to the OS.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index d89a648fe710..5fe6bd5cc4c7 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -65,6 +65,7 @@ static enum {
         ICH_FORCE_HPET_RESUME,
         VT8237_FORCE_HPET_RESUME,
         NVIDIA_FORCE_HPET_RESUME,
+        ATI_FORCE_HPET_RESUME,
 } force_hpet_resume_type;
 
 static void __iomem *rcba_base;
@@ -330,6 +331,31 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235,
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237,
                          vt8237_force_enable_hpet);
 
+static void ati_force_hpet_resume(void)
+{
+        pci_write_config_dword(cached_dev, 0x14, 0xfed00000);
+        printk(KERN_DEBUG "Force enabled HPET at resume\n");
+}
+
+static void ati_force_enable_hpet(struct pci_dev *dev)
+{
+        u32 uninitialized_var(val);
+
+        if (!hpet_force_user || hpet_address || force_hpet_address)
+                return;
+
+        pci_write_config_dword(dev, 0x14, 0xfed00000);
+        pci_read_config_dword(dev, 0x14, &val);
+        force_hpet_address = val;
+        force_hpet_resume_type = ATI_FORCE_HPET_RESUME;
+        dev_printk(KERN_DEBUG, &dev->dev, "Force enabled HPET at 0x%lx\n",
+                   force_hpet_address);
+        cached_dev = dev;
+        return;
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_IXP400_SMBUS,
+                         ati_force_enable_hpet);
+
 /*
  * Undocumented chipset feature taken from LinuxBIOS.
  */
@@ -397,6 +423,9 @@ void force_hpet_resume(void)
         case NVIDIA_FORCE_HPET_RESUME:
                 nvidia_force_hpet_resume();
                 return;
+        case ATI_FORCE_HPET_RESUME:
+                ati_force_hpet_resume();
+                return;
         default:
                 break;
         }