[RFC,PATCH 2/7 v2] Generic support for fixed-rate clocks
From: Jeremy Kerr <hidden>
Date: 2010-01-12 06:59:57
Also in:
linux-arm-kernel, lkml
Subsystem:
clk api, the rest · Maintainers:
Russell King, Linus Torvalds
Since most platforms will need a fixed-rate clock, add one. This will also serve as a basic example of an implementation of struct clk. Signed-off-by: Jeremy Kerr <redacted> --- include/linux/clk.h | 12 ++++++++++++ kernel/Makefile | 1 + kernel/clk.c | 25 +++++++++++++++++++++++++ 3 files changed, 38 insertions(+)
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 1a6199e..8293421 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h@@ -97,6 +97,18 @@ static inline struct clk *clk_get_parent(struct clk *clk) return ERR_PTR(-ENOSYS); } +/* Simple fixed-rate clock */ +struct clk_fixed { + struct clk clk; + unsigned long rate; +}; + +extern struct clk_operations clk_fixed_operations; + +#define DEFINE_CLK_FIXED(r) { \ + .clk = { .ops = &clk_fixed_operations }, \ + .rate = (r) \ +}; #else /* !CONFIG_USE_COMMON_STRUCT_CLK */
diff --git a/kernel/Makefile b/kernel/Makefile
index 864ff75..f63d021 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile@@ -100,6 +100,7 @@ obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-work-debugfs.o obj-$(CONFIG_PERF_EVENTS) += perf_event.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o +obj-$(CONFIG_USE_COMMON_STRUCT_CLK) += clk.o ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/clk.c b/kernel/clk.c
new file mode 100644
index 0000000..353736c
--- /dev/null
+++ b/kernel/clk.c@@ -0,0 +1,25 @@ +/* + * Copyright (C) 2010 Canonical Ltd <jeremy.kerr@canonical.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Standard functionality for the common clock API. + */ + +#include <linux/module.h> +#include <linux/clk.h> + +#define to_clk_fixed(clk) (container_of(clk, struct clk_fixed, clk)) + +static unsigned long clk_fixed_get_rate(struct clk *clk) +{ + return to_clk_fixed(clk)->rate; +} + +struct clk_operations clk_fixed_operations = { + .get_rate = clk_fixed_get_rate, +}; + +EXPORT_SYMBOL_GPL(clk_fixed_operations);