[PATCH] x86 reboot: Add reboot fixup for gx1/cs5530a

This patch by Jaya Kumar introduces a generic infrastructure to deal with
x86 chipsets with nonstandard reset sequences, and adds support for the
Geode gx1/cs5530a chipset.

Signed-off-by: Jaya Kumar <jayalk@intworks.biz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/arch/i386/kernel/reboot_fixups.c b/arch/i386/kernel/reboot_fixups.c
new file mode 100644
index 000000000000..1b183b378c2c
--- /dev/null
+++ b/arch/i386/kernel/reboot_fixups.c
@@ -0,0 +1,56 @@
+/*
+ * linux/arch/i386/kernel/reboot_fixups.c
+ *
+ * This is a good place to put board specific reboot fixups.
+ *
+ * List of supported fixups:
+ * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
+ *
+ */
+
+#include <asm/delay.h>
+#include <linux/pci.h>
+
+static void cs5530a_warm_reset(struct pci_dev *dev)
+{
+        /* writing 1 to the reset control register, 0x44 causes the
+        cs5530a to perform a system warm reset */
+        pci_write_config_byte(dev, 0x44, 0x1);
+        udelay(50); /* shouldn't get here but be safe and spin-a-while */
+        return;
+}
+
+struct device_fixup {
+        unsigned int vendor;
+        unsigned int device;
+        void (*reboot_fixup)(struct pci_dev *);
+};
+
+static struct device_fixup fixups_table[] = {
+{ PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
+};
+
+/*
+ * we see if any fixup is available for our current hardware. if there
+ * is a fixup, we call it and we expect to never return from it. if we
+ * do return, we keep looking and then eventually fall back to the
+ * standard mach_reboot on return.
+ */
+void mach_reboot_fixups(void)
+{
+        struct device_fixup *cur;
+        struct pci_dev *dev;
+        int i;
+
+        for (i=0; i < (sizeof(fixups_table)/sizeof(fixups_table[0])); i++) {
+                cur = &(fixups_table[i]);
+                dev = pci_get_device(cur->vendor, cur->device, 0);
+                if (!dev)
+                        continue;
+
+                cur->reboot_fixup(dev);
+        }
+
+        printk(KERN_WARNING "No reboot fixup found for your hardware\n");
+}
+