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author | Geert Uytterhoeven <geert+renesas@glider.be> | 2019-08-28 15:23:06 +0200 |
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committer | Stephen Boyd <sboyd@kernel.org> | 2020-01-05 19:12:58 -0800 |
commit | 37215da5553eb00616291a82decb958bb2d98fc1 (patch) | |
tree | ba6716cd3047ea4dae77349c36a91ff83b3c30ba /drivers | |
parent | e42617b825f8073569da76dc4510bfa019b1c35a (diff) | |
download | linux-37215da5553eb00616291a82decb958bb2d98fc1.tar.bz2 |
clk: Add support for setting clk_rate via debugfs
For testing, it is useful to be able to specify a clock rate manually.
As this is a dangerous feature, it is not enabled by default.
Users need to modify the source directly and #define
CLOCK_ALLOW_WRITE_DEBUGFS.
This follows the spirit of commit 09c6ecd394105c48 ("regmap: Add support
for writing to regmap registers via debugfs").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/20190828132306.19012-1-geert+renesas@glider.be
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/clk/clk.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index b68e200829f2..9c5b9419e585 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2996,6 +2996,41 @@ static int clk_dump_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(clk_dump); +#undef CLOCK_ALLOW_WRITE_DEBUGFS +#ifdef CLOCK_ALLOW_WRITE_DEBUGFS +/* + * This can be dangerous, therefore don't provide any real compile time + * configuration option for this feature. + * People who want to use this will need to modify the source code directly. + */ +static int clk_rate_set(void *data, u64 val) +{ + struct clk_core *core = data; + int ret; + + clk_prepare_lock(); + ret = clk_core_set_rate_nolock(core, val); + clk_prepare_unlock(); + + return ret; +} + +#define clk_rate_mode 0644 +#else +#define clk_rate_set NULL +#define clk_rate_mode 0444 +#endif + +static int clk_rate_get(void *data, u64 *val) +{ + struct clk_core *core = data; + + *val = core->rate; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n"); + static const struct { unsigned long flag; const char *name; @@ -3145,7 +3180,8 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) root = debugfs_create_dir(core->name, pdentry); core->dentry = root; - debugfs_create_ulong("clk_rate", 0444, root, &core->rate); + debugfs_create_file("clk_rate", clk_rate_mode, root, core, + &clk_rate_fops); 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); |