Hi Jeremy,
Great ideal to make it beyond ARM specific. Below is the updated patch as per your comments.
From 5a3e2d3bf577e3059c9254a61d671910ab170623 Mon Sep 17 00:00:00 2001
From: Yong Shen yong.shen@linaro.org Date: Tue, 16 Nov 2010 15:00:28 +0800 Subject: [PATCH] export clock debug information to user space
create a tree-like directory structure in debugfs so user space tools like powerdebug can generate readable clock information. more functions tend to be add in, like individual clock enable/disable by writing to this debugfs.
Signed-off-by: Yong Shen yong.shen@linaro.org --- arch/arm/common/Kconfig | 7 +++ arch/arm/common/clkdev.c | 28 +++++++++++++ arch/arm/plat-mxc/clock-common.c | 5 ++- include/linux/clk.h | 19 ++++++++- kernel/clk.c | 83 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 139 insertions(+), 3 deletions(-)
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig index 0a34c81..0300c95 100644 --- a/arch/arm/common/Kconfig +++ b/arch/arm/common/Kconfig @@ -41,3 +41,10 @@ config SHARP_SCOOP config COMMON_CLKDEV bool select HAVE_CLK + +config CLK_DEBUG + bool "clock debug information export to user space" + depends on COMMON_CLKDEV && PM_DEBUG && DEBUG_FS + default n + help + export clk debug information to user space diff --git a/arch/arm/common/clkdev.c b/arch/arm/common/clkdev.c index 9e4c4d9..5f4a309 100644 --- a/arch/arm/common/clkdev.c +++ b/arch/arm/common/clkdev.c @@ -19,6 +19,9 @@ #include <linux/mutex.h> #include <linux/clk.h> #include <linux/slab.h> +#ifdef CONFIG_CLK_DEBUG +#include <linux/debugfs.h> +#endif
#include <asm/clkdev.h>
@@ -186,3 +189,28 @@ void clkdev_drop(struct clk_lookup *cl) kfree(cl); } EXPORT_SYMBOL(clkdev_drop); + +#ifdef CONFIG_CLK_DEBUG +static int __init clk_debugfs_init(void) +{ + struct clk_lookup *cl; + struct dentry *d; + int err; + + d = debugfs_create_dir("clocks", NULL); + if (!d) + return -ENOMEM; + + list_for_each_entry(cl, &clocks, node) { + err = clk_debugfs_register(cl->clk, d); + if (err) + goto err_out; + } + return 0; +err_out: + debugfs_remove_recursive(d); + return err; +} +late_initcall(clk_debugfs_init); + +#endif diff --git a/arch/arm/plat-mxc/clock-common.c b/arch/arm/plat-mxc/clock-common.c index 8911813..20d38a8 100644 --- a/arch/arm/plat-mxc/clock-common.c +++ b/arch/arm/plat-mxc/clock-common.c @@ -97,7 +97,10 @@ unsigned long clk_mxc_get_rate(struct clk *_clk) if (clk->get_rate) return clk->get_rate(clk);
- return clk_get_rate(clk->parent); + if (clk->parent) + return clk_get_rate(clk->parent); + + return 0; }
/* Round the requested clock rate to the nearest supported diff --git a/include/linux/clk.h b/include/linux/clk.h index 56416b7..751c086 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -44,16 +44,28 @@ struct device; * registered with the arch-specific clock management code; the clock driver * code does not need to handle these. */ +#define CLK_NAME_LEN 32 struct clk { const struct clk_ops *ops; unsigned int enable_count; struct mutex mutex; +#ifdef CONFIG_CLK_DEBUG + char name[CLK_NAME_LEN]; + struct dentry *dentry; +#endif };
-#define INIT_CLK(name, o) { \ +#ifdef CONFIG_CLK_DEBUG +#define __INIT_CLK_DEBUG(n) .name = #n, +#else +#define __INIT_CLK_DEBUG(n) +#endif + +#define INIT_CLK(clk_name, o) { \ .ops = &o, \ .enable_count = 0, \ - .mutex = __MUTEX_INITIALIZER(name.mutex), \ + .mutex = __MUTEX_INITIALIZER(clk_name.mutex), \ + __INIT_CLK_DEBUG(clk_name) \ }
struct clk_ops { @@ -245,4 +257,7 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id); int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, struct device *dev);
+#ifdef CONFIG_CLK_DEBUG +int clk_debugfs_register(struct clk *clk, struct dentry *root); +#endif #endif diff --git a/kernel/clk.c b/kernel/clk.c index 32f25ef..97e5e66 100644 --- a/kernel/clk.c +++ b/kernel/clk.c @@ -12,6 +12,10 @@ #include <linux/mutex.h> #include <linux/module.h>
+#ifdef CONFIG_CLK_DEBUG +#include <linux/debugfs.h> +#endif + int clk_enable(struct clk *clk) { int ret = 0; @@ -113,3 +117,82 @@ struct clk_ops clk_fixed_ops = { .get_rate = clk_fixed_get_rate, }; EXPORT_SYMBOL_GPL(clk_fixed_ops); + +#ifdef CONFIG_CLK_DEBUG +/* + * debugfs support to trace clock tree hierarchy and attributes + */ +static int clk_debug_rate_get(void *data, u64 *val) +{ + struct clk *clk = data; + + *val = (u64)clk_get_rate(clk); + return 0; +} +DEFINE_SIMPLE_ATTRIBUTE(clk_debug_rate_fops, clk_debug_rate_get, NULL, + "%llu\n"); + + +static int clk_debugfs_register_one(struct clk *clk, struct dentry *root) +{ + int err; + struct dentry *d, *child, *child_tmp; + struct clk *pa = clk_get_parent(clk); + + if (pa && !IS_ERR(pa)) + d = debugfs_create_dir(clk->name, pa->dentry); + else + d = debugfs_create_dir(clk->name, root); + + if (!d) + return -ENOMEM; + + clk->dentry = d; + + d = debugfs_create_u32("enable_count", S_IRUGO, clk->dentry, + (u32 *)&clk->enable_count); + if (!d) { + err = -ENOMEM; + goto err_out; + } + + d = debugfs_create_file("rate", S_IRUGO, clk->dentry, (void *)clk, + &clk_debug_rate_fops); + if (!d) { + err = -ENOMEM; + goto err_out; + } + + return 0; + +err_out: + d = clk->dentry; + list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child) + debugfs_remove(child); + debugfs_remove(clk->dentry); + return err; +} + +int clk_debugfs_register(struct clk *clk, struct dentry *root) +{ + int err; + struct clk *pa; + + pa = clk_get_parent(clk); + + if (pa && !IS_ERR(pa) && !pa->dentry) { + err = clk_debugfs_register(pa, root); + if (err) + return err; + } + + if (!clk->dentry) { + err = clk_debugfs_register_one(clk, root); + if (err) + return err; + } + return 0; +} +EXPORT_SYMBOL_GPL(clk_debugfs_register); + +#endif /* defined CONFIG_CLK_DEBUG */