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authorJohn Keeping <john@metanate.com>2023-04-20 12:38:04 +0200
committerStephen Boyd <sboyd@kernel.org>2023-10-24 05:20:57 +0200
commite43d31915cc4fca4e04daeca6c0ff25cc57cf956 (patch)
tree47d6133cd16753f97eb293f04d6335fc4234a89e /drivers/clk/clk.c
parentclk: Show active consumers of clocks in debugfs (diff)
downloadlinux-e43d31915cc4fca4e04daeca6c0ff25cc57cf956.tar.xz
linux-e43d31915cc4fca4e04daeca6c0ff25cc57cf956.zip
clk: Allow phase adjustment from debugfs
For testing it may be useful to manually adjust a clock's phase. Add support for writing to the existing clk_phase debugfs file, with the written value clamped to [0, 360) to match the behaviour of the clk_set_phase() function. This is a dangerous feature, so use the existing define CLOCK_ALLOW_WRITE_DEBUGFS to allow it only if the source is modified. Signed-off-by: John Keeping <john@metanate.com> Link: https://lore.kernel.org/r/20230420103805.125246-1-john@metanate.com Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 0544615d2a1d..2f0885e4f6bf 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3343,6 +3343,21 @@ static int clk_rate_set(void *data, u64 val)
#define clk_rate_mode 0644
+static int clk_phase_set(void *data, u64 val)
+{
+ struct clk_core *core = data;
+ int degrees = do_div(val, 360);
+ int ret;
+
+ clk_prepare_lock();
+ ret = clk_core_set_phase_nolock(core, degrees);
+ clk_prepare_unlock();
+
+ return ret;
+}
+
+#define clk_phase_mode 0644
+
static int clk_prepare_enable_set(void *data, u64 val)
{
struct clk_core *core = data;
@@ -3370,6 +3385,9 @@ DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
#else
#define clk_rate_set NULL
#define clk_rate_mode 0444
+
+#define clk_phase_set NULL
+#define clk_phase_mode 0644
#endif
static int clk_rate_get(void *data, u64 *val)
@@ -3385,6 +3403,16 @@ static int clk_rate_get(void *data, u64 *val)
DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
+static int clk_phase_get(void *data, u64 *val)
+{
+ struct clk_core *core = data;
+
+ *val = core->phase;
+ return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
+
static const struct {
unsigned long flag;
const char *name;
@@ -3575,7 +3603,8 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
- debugfs_create_u32("clk_phase", 0444, root, &core->phase);
+ debugfs_create_file("clk_phase", clk_phase_mode, root, core,
+ &clk_phase_fops);
debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);