Subject: [PATCH] clk: bulk: call of_clk_get() when id is NULL

From: [email-masked] (Stephen Boyd)
Date: Wed, 9 Aug 2017 10:33:18 -0700

On 08/09, Shawn Guo wrote:
> From: Shawn Guo <[email-masked]>
> 
> Most of clk API users have their clocks defined in device tree, and
> client drivers will have to parse clk ids from DT 'clock-names'
> property before using clk_bulk_get().  This is a burden for client
> driver code.  And 'clock-names' being an optional DT property makes
> it even worse.  The client driver will have no way to provide clock
> id.
> 
> The patch makes a little improvement on clk_bulk_get() to call
> of_clk_get() with index for DT users, if clock id is not available,
> so that client drivers working with DT can use clk_bulk_get() to
> retrieve clocks more easily.
> 
> Signed-off-by: Shawn Guo <[email-masked]>
> ---
>  drivers/clk/clk-bulk.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> 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,
>  		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.

Also, this patch needs to document the new behavior somewhere in
the kernel-doc for this function.

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