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>

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7fdcbd3f4da5a7756f2f1fb01a467a11b107092b..a32b7a9c65d3a462a5cd53af31b6bb251f2db149 100644 (file)
--- 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 f93453d0167305d7633495661a5f92d7720aa32a..a33f792402176f79a6c581eeed1e052b8c06d0da 100644 (file)
--- 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 (file)
index 0000000..bdabdaa
--- /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();
+       }
+}

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index d1ea7ce0b4cb95c9e61935aefbcb09c12f49bdbc..1e744c5a0ffe974c76debea9ea0d889098003d23 100644 (file)
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -149,6 +149,14 @@
 #define TRACE_SYSCALLS()
 #endif
 
+#ifdef CONFIG_CLKSRC_OF
+#define CLKSRC_OF_TABLES() . = ALIGN(8);                               \
+                          VMLINUX_SYMBOL(__clksrc_of_table) = .;       \
+                          *(__clksrc_of_table)                         \
+                          *(__clksrc_of_table_end)
+#else
+#define CLKSRC_OF_TABLES()
+#endif
 
 #define KERNEL_DTB()                                                   \
        STRUCT_ALIGN();                                                 \
@@ -493,6 +501,7 @@
        DEV_DISCARD(init.rodata)                                        \
        CPU_DISCARD(init.rodata)                                        \
        MEM_DISCARD(init.rodata)                                        \
+       CLKSRC_OF_TABLES()                                              \
        KERNEL_DTB()
 
 #define INIT_TEXT                                                      \

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 4dceaf8ae1525e57a0d6f7911e8dddac7047da4d..7944f14ea947970446ce61d36e5c3a53aa882a7c 100644 (file)
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -332,4 +332,13 @@ extern int clocksource_mmio_init(void __iomem *, const char *,
 
 extern int clocksource_i8253_init(void);
 
+#ifdef CONFIG_CLKSRC_OF
+extern void clocksource_of_init(void);
+
+#define CLOCKSOURCE_OF_DECLARE(name, compat, fn)                       \
+       static const struct of_device_id __clksrc_of_table_##name       \
+               __used __section(__clksrc_of_table)                     \
+                = { .compatible = compat, .data = fn };
+#endif
+
 #endif /* _LINUX_CLOCKSOURCE_H */