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clk: Add support for setting clk_rate via debugfs

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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 09c6ecd394 ("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>
This commit is contained in:
Geert Uytterhoeven 2019-08-28 15:23:06 +02:00 • committed by Stephen Boyd
parent e42617b825
commit 37215da555
1 changed files with 37 additions and 1 deletions
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38
drivers/clk/clk.c
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@ -2996,6 +2996,41 @@ static int clk_dump_show(struct seq_file *s, void *data)
} }
DEFINE_SHOW_ATTRIBUTE(clk_dump); 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 { static const struct {
unsigned long flag; unsigned long flag;
const char *name; 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); root = debugfs_create_dir(core->name, pdentry);
core->dentry = root; 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_min_rate", 0444, root, core, &clk_min_rate_fops);
debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_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_ulong("clk_accuracy", 0444, root, &core->accuracy);