clocksource: add common of_clksrc_init() function

It is desirable to move all clocksource drivers to drivers/clocksource,
yet each requires its own initialization function. We'd rather not
pollute <linux/> with a header for each function. Instead, create a
single of_clksrc_init() function which will determine which clocksource
driver to initialize based on device tree.

Based on a similar patch for drivers/irqchip by Thomas Petazzoni.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

3 files changed, 39 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7fdcbd3f4da5..a32b7a9c65d3 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -1,3 +1,6 @@
+config CLKSRC_OF
+        bool
+
 config CLKSRC_I8253
         bool
 
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index f93453d01673..a33f79240217 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_CLKSRC_OF) += clksrc-of.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)  += tcb_clksrc.o
 obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o
 obj-$(CONFIG_X86_PM_TIMER)      += acpi_pm.o
diff --git a/drivers/clocksource/clksrc-of.c b/drivers/clocksource/clksrc-of.c
new file mode 100644
index 000000000000..bdabdaa8d00f
--- /dev/null
+++ b/drivers/clocksource/clksrc-of.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/of.h>
+
+extern struct of_device_id __clksrc_of_table[];
+
+static const struct of_device_id __clksrc_of_table_sentinel
+        __used __section(__clksrc_of_table_end);
+
+void __init clocksource_of_init(void)
+{
+        struct device_node *np;
+        const struct of_device_id *match;
+        void (*init_func)(void);
+
+        for_each_matching_node_and_match(np, __clksrc_of_table, &match) {
+                init_func = match->data;
+                init_func();
+        }
+}