mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

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>
This commit is contained in:
John Keeping 2023-04-20 11:38:04 +01:00 committed by Stephen Boyd
parent dcce5cc782
commit e43d31915c
1 changed files with 30 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/clk/clk.c
View File

@ -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);