-----Original Message-----
From: Shawn Guo [mailto:shawnguo at kernel.org]
Sent: Sunday, August 13, 2017 10:19 PM
To: Stephen Boyd
Cc: Michael Turquette; A.s. Dong; linux-clk at vger.kernel.org; linux-arm-
kernel at lists.infradead.org; Shawn Guo
Subject: Re: [PATCH] clk: bulk: call of_clk_get() when id is NULL

Hi Stephen,

On Wed, Aug 09, 2017 at 10:33:18AM -0700, Stephen Boyd wrote:

quoted

quoted

diff --git a/drivers/clk/clk-bulk.c b/drivers/clk/clk-bulk.c index

c834f5abfc49..65cee595a67e 100644

--- a/drivers/clk/clk-bulk.c
+++ b/drivers/clk/clk-bulk.c

@@ -39,7 +39,10 @@ int __must_check clk_bulk_get(struct device *dev,

int num_clks,

quoted

quoted

 		clks[i].clk = NULL;

 	for (i = 0; i < num_clks; i++) {
-		clks[i].clk = clk_get(dev, clks[i].id);
+		if (clks[i].id)
+			clks[i].clk = clk_get(dev, clks[i].id);
+		else if (dev->of_node)
+			clks[i].clk = of_clk_get(dev->of_node, i);

This seems a little too magical. The omission of an id in an array of
clks would mean that only that one clk is acquired through
of_clk_get(). We could have a mixture of ids and no ids for some
device, and then do very odd things.

How about we add a flag to clk_bulk_data that indicates we want it to
use of_clk_get() instead of clk_get() for all of the clks?
Then the id is ignored for the entire function.

I have sent v2 to add a flag to clk_bulk_data to address your comments.
But I just found it might not be what you want exactly, because the
current bulk clk APIs defines clk_bulk_data in a different way from what
you are asking here.

It seems that you think clk_bulk_data represents all the clocks that bulk
APIs manage, but actually it only represents one of the multiple clocks.
Callers need to prepare an array of clk_bulk_data to represent multiple
clocks.  That said, the flag we add to clk_bulk_data only affects one
clock instead of all clocks.

I feel this is something we can improve.  clk_bulk_data can be used to
represent all clocks, something like below.  In this case, bulk clk APIs
do not need to take num_clks as a separate parameter, and callers do not
need to maintain multiple clk_bulk_data instances.  Since we do not have
any in tree users of bulk clk APIs yet, we can make this semantic change
quickly.  Thoughts?

Flags may be better used for extending per clk feature support in the future.

IMHO how about implement a of_clk_bulk_get() to handle this issue as we already
have a of_clk_get?
e.g.

int __must_check of_clk_bulk_get(struct device_node *np, int num_clks,
                              struct clk_bulk_data *clks)
{
        for (i = 0; i < num_clks; i++) {
                clks[i].clk = of_clk_get(dev, clks[i].id);
...

}

Then it's less intrusive.

Regards
Dong Aisheng