Commit 37215da5 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Stephen Boyd
Browse files

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 09c6ecd3 ("regmap: Add support
for writing to regmap registers via debugfs").

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/20190828132306.19012-1-geert+renesas@glider.be


Suggested-by: default avatarStephen Boyd <sboyd@kernel.org>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent e42617b8

drivers/clk/clk.c

+37 −1
Original line number Diff line number Diff line
@@ -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);