diff options
| author | Mike Tipton <mdtipton@codeaurora.org> | 2020-06-29 17:30:24 -0700 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2020-07-24 02:03:58 -0700 |
| commit | 03111b1088f18f93d38e888c41e8a1e6aba9f8bb (patch) | |
| tree | 1fb5683436669d697ff5000fde0dfd223967538b /drivers/clk/clk.c | |
| parent | b3a9e3b9622ae10064826dccb4f7a52bd88c7407 (diff) | |
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.c | 29 |
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, |