Useful for testing mux clocks. One can write the index of the parent to
be set into clk_parent node, starting from 0. Example
# cd /sys/kernel/debug/clk/mout_peri_bus
# cat clk_possible_parents
dout_shared0_div4 dout_shared1_div4
# cat clk_parent
dout_shared0_div4
# echo 1 > clk_parent
# cat clk_parent
dout_shared1_div4
CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
order to use this feature.
Signed-off-by: Sam Protsenko <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
---
Changes in v6:
- Added R-b tag by Geert Uytterhoeven
- Removed curly braces around 'else' block (now delta is minimal and
the code looks better)
Changes in v5:
- Used kstrtou8_from_user() API
- Got rid of code duplication
- Fixed typo in commit message
- Added R-b tag by Andy Shevchenko
Changes in v4:
- Fixed the commit title
Changes in v3:
- Removed unwanted changes added by mistake
Changes in v2:
- Merged write() function into existing 'clk_parent' file
- Removed 'if (val >= core->num_parents)' check
- Removed incorrect usage of IS_ERR_OR_NULL()
drivers/clk/clk.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 65508eb89ec9..bf1eadfeaee0 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3214,6 +3214,42 @@ static int current_parent_show(struct seq_file *s, void *data)
}
DEFINE_SHOW_ATTRIBUTE(current_parent);
+#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
+static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *s = file->private_data;
+ struct clk_core *core = s->private;
+ struct clk_core *parent;
+ u8 idx;
+ int err;
+
+ err = kstrtou8_from_user(ubuf, count, 0, &idx);
+ if (err < 0)
+ return err;
+
+ parent = clk_core_get_parent_by_index(core, idx);
+ if (!parent)
+ return -ENOENT;
+
+ clk_prepare_lock();
+ err = clk_core_set_parent_nolock(core, parent);
+ clk_prepare_unlock();
+ if (err)
+ return err;
+
+ return count;
+}
+
+static const struct file_operations current_parent_rw_fops = {
+ .open = current_parent_open,
+ .write = current_parent_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif
+
static int clk_duty_cycle_show(struct seq_file *s, void *data)
{
struct clk_core *core = s->private;
@@ -3281,6 +3317,12 @@ static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
&clk_prepare_enable_fops);
#endif
+#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
+ if (core->num_parents > 1)
+ debugfs_create_file("clk_parent", 0644, root, core,
+ ¤t_parent_rw_fops);
+ else
+#endif
if (core->num_parents > 0)
debugfs_create_file("clk_parent", 0444, root, core,
¤t_parent_fops);
--
2.30.2
Hi Sam,
On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
<[email protected]> wrote:
>
> Useful for testing mux clocks. One can write the index of the parent to
> be set into clk_parent node, starting from 0. Example
>
> # cd /sys/kernel/debug/clk/mout_peri_bus
> # cat clk_possible_parents
> dout_shared0_div4 dout_shared1_div4
> # cat clk_parent
> dout_shared0_div4
> # echo 1 > clk_parent
> # cat clk_parent
> dout_shared1_div4
>
> CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> order to use this feature.
>
> Signed-off-by: Sam Protsenko <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> Reviewed-by: Geert Uytterhoeven <[email protected]>
This is useful, thanks:
Reviewed-by: Fabio Estevam <[email protected]>
On Wed, 13 Oct 2021 at 21:04, Fabio Estevam <[email protected]> wrote:
>
> Hi Sam,
>
> On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
> <[email protected]> wrote:
> >
> > Useful for testing mux clocks. One can write the index of the parent to
> > be set into clk_parent node, starting from 0. Example
> >
> > # cd /sys/kernel/debug/clk/mout_peri_bus
> > # cat clk_possible_parents
> > dout_shared0_div4 dout_shared1_div4
> > # cat clk_parent
> > dout_shared0_div4
> > # echo 1 > clk_parent
> > # cat clk_parent
> > dout_shared1_div4
> >
> > CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> > order to use this feature.
> >
> > Signed-off-by: Sam Protsenko <[email protected]>
> > Reviewed-by: Andy Shevchenko <[email protected]>
> > Reviewed-by: Geert Uytterhoeven <[email protected]>
>
> This is useful, thanks:
>
> Reviewed-by: Fabio Estevam <[email protected]>
Hi Michael, Stephen,
If there are no outstanding comments, can you please take this one?
Thanks!
On Tue, 19 Oct 2021 at 16:32, Sam Protsenko <[email protected]> wrote:
>
> On Wed, 13 Oct 2021 at 21:04, Fabio Estevam <[email protected]> wrote:
> >
> > Hi Sam,
> >
> > On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
> > <[email protected]> wrote:
> > >
> > > Useful for testing mux clocks. One can write the index of the parent to
> > > be set into clk_parent node, starting from 0. Example
> > >
> > > # cd /sys/kernel/debug/clk/mout_peri_bus
> > > # cat clk_possible_parents
> > > dout_shared0_div4 dout_shared1_div4
> > > # cat clk_parent
> > > dout_shared0_div4
> > > # echo 1 > clk_parent
> > > # cat clk_parent
> > > dout_shared1_div4
> > >
> > > CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> > > order to use this feature.
> > >
> > > Signed-off-by: Sam Protsenko <[email protected]>
> > > Reviewed-by: Andy Shevchenko <[email protected]>
> > > Reviewed-by: Geert Uytterhoeven <[email protected]>
> >
> > This is useful, thanks:
> >
> > Reviewed-by: Fabio Estevam <[email protected]>
>
> Hi Michael, Stephen,
>
> If there are no outstanding comments, can you please take this one?
>
Bump.
> Thanks!
On Mon, Nov 22, 2021 at 10:03 AM Sam Protsenko
<[email protected]> wrote:
>
> On Tue, 19 Oct 2021 at 16:32, Sam Protsenko <[email protected]> wrote:
> >
> > On Wed, 13 Oct 2021 at 21:04, Fabio Estevam <[email protected]> wrote:
> > >
> > > Hi Sam,
> > >
> > > On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
> > > <[email protected]> wrote:
> > > >
> > > > Useful for testing mux clocks. One can write the index of the parent to
> > > > be set into clk_parent node, starting from 0. Example
> > > >
> > > > # cd /sys/kernel/debug/clk/mout_peri_bus
> > > > # cat clk_possible_parents
> > > > dout_shared0_div4 dout_shared1_div4
> > > > # cat clk_parent
> > > > dout_shared0_div4
> > > > # echo 1 > clk_parent
> > > > # cat clk_parent
> > > > dout_shared1_div4
> > > >
> > > > CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> > > > order to use this feature.
> > > >
> > > > Signed-off-by: Sam Protsenko <[email protected]>
> > > > Reviewed-by: Andy Shevchenko <[email protected]>
> > > > Reviewed-by: Geert Uytterhoeven <[email protected]>
> > >
> > > This is useful, thanks:
> > >
> > > Reviewed-by: Fabio Estevam <[email protected]>
> >
> > Hi Michael, Stephen,
> >
> > If there are no outstanding comments, can you please take this one?
> >
>
> Bump.
Looks good to me.
Acked-by: Michael Turquette <[email protected]>
Stephen, can you take it into your tree?
Best,
Mike
>
> > Thanks!
--
Michael Turquette
CEO - Los Angeles, CA
http://baylibre.com/
On Tue, 23 Nov 2021 at 19:44, Michael Turquette <[email protected]> wrote:
>
> On Mon, Nov 22, 2021 at 10:03 AM Sam Protsenko
> <[email protected]> wrote:
> >
> > On Tue, 19 Oct 2021 at 16:32, Sam Protsenko <[email protected]> wrote:
> > >
> > > On Wed, 13 Oct 2021 at 21:04, Fabio Estevam <[email protected]> wrote:
> > > >
> > > > Hi Sam,
> > > >
> > > > On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
> > > > <[email protected]> wrote:
> > > > >
> > > > > Useful for testing mux clocks. One can write the index of the parent to
> > > > > be set into clk_parent node, starting from 0. Example
> > > > >
> > > > > # cd /sys/kernel/debug/clk/mout_peri_bus
> > > > > # cat clk_possible_parents
> > > > > dout_shared0_div4 dout_shared1_div4
> > > > > # cat clk_parent
> > > > > dout_shared0_div4
> > > > > # echo 1 > clk_parent
> > > > > # cat clk_parent
> > > > > dout_shared1_div4
> > > > >
> > > > > CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> > > > > order to use this feature.
> > > > >
> > > > > Signed-off-by: Sam Protsenko <[email protected]>
> > > > > Reviewed-by: Andy Shevchenko <[email protected]>
> > > > > Reviewed-by: Geert Uytterhoeven <[email protected]>
> > > >
> > > > This is useful, thanks:
> > > >
> > > > Reviewed-by: Fabio Estevam <[email protected]>
> > >
> > > Hi Michael, Stephen,
> > >
> > > If there are no outstanding comments, can you please take this one?
> > >
> >
> > Bump.
>
> Looks good to me.
>
> Acked-by: Michael Turquette <[email protected]>
>
> Stephen, can you take it into your tree?
>
Relaying "To:" Stephen.
> Best,
> Mike
>
> >
> > > Thanks!
>
>
>
> --
> Michael Turquette
> CEO - Los Angeles, CA
> http://baylibre.com/
Quoting Michael Turquette (2021-11-23 09:43:55)
> On Mon, Nov 22, 2021 at 10:03 AM Sam Protsenko
> <[email protected]> wrote:
> >
> > On Tue, 19 Oct 2021 at 16:32, Sam Protsenko <[email protected]> wrote:
> > >
> > > On Wed, 13 Oct 2021 at 21:04, Fabio Estevam <[email protected]> wrote:
> > > >
> > > > Hi Sam,
> > > >
> > > > On Wed, Oct 13, 2021 at 2:20 PM Sam Protsenko
> > > > <[email protected]> wrote:
> > > > >
> > > > > Useful for testing mux clocks. One can write the index of the parent to
> > > > > be set into clk_parent node, starting from 0. Example
> > > > >
> > > > > # cd /sys/kernel/debug/clk/mout_peri_bus
> > > > > # cat clk_possible_parents
> > > > > dout_shared0_div4 dout_shared1_div4
> > > > > # cat clk_parent
> > > > > dout_shared0_div4
> > > > > # echo 1 > clk_parent
> > > > > # cat clk_parent
> > > > > dout_shared1_div4
> > > > >
> > > > > CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> > > > > order to use this feature.
> > > > >
> > > > > Signed-off-by: Sam Protsenko <[email protected]>
> > > > > Reviewed-by: Andy Shevchenko <[email protected]>
> > > > > Reviewed-by: Geert Uytterhoeven <[email protected]>
> > > >
> > > > This is useful, thanks:
> > > >
> > > > Reviewed-by: Fabio Estevam <[email protected]>
> > >
> > > Hi Michael, Stephen,
> > >
> > > If there are no outstanding comments, can you please take this one?
> > >
> >
> > Bump.
>
> Looks good to me.
>
> Acked-by: Michael Turquette <[email protected]>
>
> Stephen, can you take it into your tree?
Sure thing.
Quoting Sam Protsenko (2021-10-13 10:20:42)
> Useful for testing mux clocks. One can write the index of the parent to
> be set into clk_parent node, starting from 0. Example
>
> # cd /sys/kernel/debug/clk/mout_peri_bus
> # cat clk_possible_parents
> dout_shared0_div4 dout_shared1_div4
> # cat clk_parent
> dout_shared0_div4
> # echo 1 > clk_parent
> # cat clk_parent
> dout_shared1_div4
>
> CLOCK_ALLOW_WRITE_DEBUGFS has to be defined in drivers/clk/clk.c in
> order to use this feature.
>
> Signed-off-by: Sam Protsenko <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> Reviewed-by: Geert Uytterhoeven <[email protected]>
> ---
Applied to clk-next