diff options
Diffstat (limited to 'arch/alpha/kernel/ns87312.c')
| -rw-r--r-- | arch/alpha/kernel/ns87312.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/alpha/kernel/ns87312.c b/arch/alpha/kernel/ns87312.c new file mode 100644 index 00000000000..342b56d24c2 --- /dev/null +++ b/arch/alpha/kernel/ns87312.c @@ -0,0 +1,38 @@ +/* + * 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); +} |