[S390] pm: power management support for SCLP drivers.

The SCLP base driver defines a new notifier call back for all upper level SCLP
drivers, like the SCLP console, etc. This guarantees that in suspend first the
upper level drivers are suspended and afterwards the SCLP base driver. For
resume it is the other way round. The SCLP base driver itself registers a
new platform device at the platform bus and gets PM notifications via
the dev_pm_ops.

In suspend, the SCLP base driver switches off the receiver and sender mask
This is done in sclp_deactivate(). After suspend all new requests will be
rejected with -EIO and no more interrupts will be received, because the masks
are switched off. For resume the sender and receiver masks are reset in
the sclp_reactivate() function.

When the SCLP console is suspended, all new messages are cached in the
sclp console buffers. In resume, all the cached messages are written to the
console. In addition to that we have an early resume function that removes
the cached messages from the suspend image.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/s390/char/sclp_rw.c b/drivers/s390/char/sclp_rw.c
index 710af42603f8..4be63be73445 100644
--- a/drivers/s390/char/sclp_rw.c
+++ b/drivers/s390/char/sclp_rw.c
@@ -1,11 +1,10 @@
 /*
- *  drivers/s390/char/sclp_rw.c
- *     driver: reading from and writing to system console on S/390 via SCLP
+ * driver: reading from and writing to system console on S/390 via SCLP
  *
- *  S390 version
- *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Martin Peschke <mpeschke@de.ibm.com>
- *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ *
+ * Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ *	      Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
 #include <linux/kmod.h>
@@ -26,9 +25,16 @@
  */
 #define MAX_SCCB_ROOM (PAGE_SIZE - sizeof(struct sclp_buffer))
 
+static void sclp_rw_pm_event(struct sclp_register *reg,
+			     enum sclp_pm_event sclp_pm_event)
+{
+	sclp_console_pm_event(sclp_pm_event);
+}
+
 /* Event type structure for write message and write priority message */
 static struct sclp_register sclp_rw_event = {
-	.send_mask = EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK
+	.send_mask = EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK,
+	.pm_event_fn = sclp_rw_pm_event,
 };
 
 /*