From 37215da5553eb00616291a82decb958bb2d98fc1 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 28 Aug 2019 15:23:06 +0200 Subject: [PATCH] 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 Link: https://lkml.kernel.org/r/20190828132306.19012-1-geert+renesas@glider.be Suggested-by: Stephen Boyd Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) 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); -- 2.20.1