[flashrom] [commit] r904 - trunk

[repository service]

Author: hailfinger
Date: Sun Feb 14 02:20:28 2010
New Revision: 904
URL: http://flashrom.org/trac/coreboot/changeset/904

Log:
Some programmers want to run certain functions during programmer
shutdown, but the function choice depends on the code path taken during
programmer init.
Rather than rebuilding the whole init logic in the shutdown function, it
is now possible to register functions for execution on programmer
shutdown.
The behaviour is similar to atexit(), but the registered functions will
be run on programmer shutdown instead of on exit and the functions will
be called with a void * argument that is specified on registration.
Registered functions must have the prototype
void function(void *);
and will be executed in reverse registration order directly before
calling the programmer-specific shutdown() function. It is recommended
to have shutdown() only disable programmer/hardware access and leave all
code path sensitive shutdown to functions registered with
register_shutdown().

The most prominent use case is resetting the EC after flashing on
laptops.

Note: There are quite a few code paths in flashrom which proceed to
terminate flashrom without any programmer shutdown. Those code paths
will not get the benefit of register_shutdown() and they should be
changed wherever possible.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net>
Acked-by: Michael Karcher <flashrom at mkarcher.dialup.fu-berlin.de>

Modified:
   trunk/flash.h
   trunk/flashrom.c

Modified: trunk/flash.h
==============================================================================
--- trunk/flash.h	Sun Feb 14 02:00:36 2010	(r903)
+++ trunk/flash.h	Sun Feb 14 02:20:28 2010	(r904)
@@ -99,6 +99,8 @@
 
 extern const struct programmer_entry programmer_table[];
 
+int register_shutdown(void (*function) (void *data), void *data);
+
 int programmer_init(void);
 int programmer_shutdown(void);
 void *programmer_map_flash_region(const char *descr, unsigned long phys_addr,

Modified: trunk/flashrom.c
==============================================================================
--- trunk/flashrom.c	Sun Feb 14 02:00:36 2010	(r903)
+++ trunk/flashrom.c	Sun Feb 14 02:20:28 2010	(r904)
@@ -308,6 +308,35 @@
 	{}, /* This entry corresponds to PROGRAMMER_INVALID. */
 };
 
+#define SHUTDOWN_MAXFN 4
+static int shutdown_fn_count = 0;
+struct shutdown_func_data {
+	void (*func) (void *data);
+	void *data;
+} shutdown_fn[SHUTDOWN_MAXFN];
+
+/* Register a function to be executed on programmer shutdown.
+ * The advantage over atexit() is that you can supply a void pointer which will
+ * be used as parameter to the registered function upon programmer shutdown.
+ * This pointer can point to arbitrary data used by said function, e.g. undo
+ * information for GPIO settings etc. If unneeded, set data=NULL.
+ * Please note that the first (void *data) belongs to the function signature of
+ * the function passed as first parameter.
+ */
+int register_shutdown(void (*function) (void *data), void *data)
+{
+	if (shutdown_fn_count >= SHUTDOWN_MAXFN) {
+		msg_perr("Tried to register more than %n shutdown functions.\n",
+			 SHUTDOWN_MAXFN);
+		return 1;
+	}
+	shutdown_fn[shutdown_fn_count].func = function;
+	shutdown_fn[shutdown_fn_count].data = data;
+	shutdown_fn_count++;
+
+	return 0;
+}
+
 int programmer_init(void)
 {
 	return programmer_table[programmer].init();
@@ -315,6 +344,10 @@
 
 int programmer_shutdown(void)
 {
+	int i;
+
+	for (i = shutdown_fn_count - 1; i >= 0; i--)
+		shutdown_fn[i].func(shutdown_fn[i].data);
 	return programmer_table[programmer].shutdown();
 }