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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/alpha/kernel/ns87312.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/alpha/kernel/ns87312.c')
-rw-r--r--arch/alpha/kernel/ns87312.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/alpha/kernel/ns87312.c b/arch/alpha/kernel/ns87312.c
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+++ b/arch/alpha/kernel/ns87312.c
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+/*
+ * linux/arch/alpha/kernel/ns87312.c
+ */
+
+#include <linux/init.h>
+#include <asm/io.h>
+#include "proto.h"
+
+
+/*
+ * The SRM console *disables* the IDE interface, this code ensures it's
+ * enabled.
+ *
+ * This code bangs on a control register of the 87312 Super I/O chip
+ * that implements parallel port/serial ports/IDE/FDI. Depending on
+ * the motherboard, the Super I/O chip can be configured through a
+ * pair of registers that are located either at I/O ports 0x26e/0x26f
+ * or 0x398/0x399. Unfortunately, autodetecting which base address is
+ * in use works only once (right after a reset). The Super I/O chip
+ * has the additional quirk that configuration register data must be
+ * written twice (I believe this is a safety feature to prevent
+ * accidental modification---fun, isn't it?).
+ */
+
+void __init
+ns87312_enable_ide(long ide_base)
+{
+ int data;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ outb(0, ide_base); /* set the index register for reg #0 */
+ data = inb(ide_base+1); /* read the current contents */
+ outb(0, ide_base); /* set the index register for reg #0 */
+ outb(data | 0x40, ide_base+1); /* turn on IDE */
+ outb(data | 0x40, ide_base+1); /* turn on IDE, really! */
+ local_irq_restore(flags);
+}