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authorMike Tipton <mdtipton@codeaurora.org>2020-06-29 17:30:24 -0700
committerStephen Boyd <sboyd@kernel.org>2020-07-24 02:03:58 -0700
commit03111b1088f18f93d38e888c41e8a1e6aba9f8bb (patch)
tree1fb5683436669d697ff5000fde0dfd223967538b /drivers/clk/clk.c
parentb3a9e3b9622ae10064826dccb4f7a52bd88c7407 (diff)
downloadlinux-03111b1088f18f93d38e888c41e8a1e6aba9f8bb.tar.gz
clk: Add support for enabling/disabling clocks from debugfs
For test and debug purposes, it's simple enough to enable or disable clocks from shell. Add a new debugfs file 'clk_prepare_enable' that calls clk_prepare_enable() when writing "1" and clk_disable_unprepare() when writing "0". This can have security implications, so only support it when the code has been modified to #define CLOCK_ALLOW_WRITE_DEBUGFS. Signed-off-by: Mike Tipton <mdtipton@codeaurora.org> Link: https://lore.kernel.org/r/20200630003024.6282-1-mdtipton@codeaurora.org [sboyd@kernel.org: Reword commit text and remove comment update] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 3f588ed06ce3..4d455a657b01 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3039,6 +3039,31 @@ static int clk_rate_set(void *data, u64 val)
}
#define clk_rate_mode 0644
+
+static int clk_prepare_enable_set(void *data, u64 val)
+{
+ struct clk_core *core = data;
+ int ret = 0;
+
+ if (val)
+ ret = clk_prepare_enable(core->hw->clk);
+ else
+ clk_disable_unprepare(core->hw->clk);
+
+ return ret;
+}
+
+static int clk_prepare_enable_get(void *data, u64 *val)
+{
+ struct clk_core *core = data;
+
+ *val = core->enable_count && core->prepare_count;
+ return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
+ clk_prepare_enable_set, "%llu\n");
+
#else
#define clk_rate_set NULL
#define clk_rate_mode 0444
@@ -3216,6 +3241,10 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
debugfs_create_file("clk_duty_cycle", 0444, root, core,
&clk_duty_cycle_fops);
+#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
+ debugfs_create_file("clk_prepare_enable", 0644, root, core,
+ &clk_prepare_enable_fops);
+#endif
if (core->num_parents > 0)
debugfs_create_file("clk_parent", 0444, root, core,