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Date:   Thu, 12 Oct 2017 16:17:09 -0700
From:   Stephen Boyd <sboyd@codeaurora.org>
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     linux-clk@vger.kernel.org, Stephen Warren <swarren@wwwdotorg.org>,
        linux-fbdev@vger.kernel.org,
        Michael Turquette <mturquette@baylibre.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        linux-kernel@vger.kernel.org, Hans de Goede <hdegoede@redhat.com>,
        Russell King <linux@armlinux.org.uk>,
        Shawn Guo <shawnguo@kernel.org>,
        Dong Aisheng <aisheng.dong@nxp.com>
Subject: Re: [RFC PATCH] clk: move of_clk_get_parent_count() declaration to
 <linux/__clk.h>
Message-ID: <20171012231709.GH18706@codeaurora.org>
References: <1507166751-2012-1-git-send-email-yamada.masahiro@socionext.com>
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On 10/05, Masahiro Yamada wrote:
> The clock consumer, drivers/video/fbdev/simplefb.c, includes
> <linux/clk-provider.h> just for calling of_clk_get_parent_count().
> This is ugly.
> 
> Looking at simplefb_clocks_get(), of_clk_get_parent_count() seems
> useful for clock consumers as well as for clock providers.
> 
> Unfortunately, we do not have a good home for declarations shared
> between consumers and providers.
> 
> Create a new header <linux/__clk.h>, and move it over to it.  This
> header must be included via <linux/clk.h> or <linux/clk-provider.h>
> (this is why it is prefixed with double-underscore).  Add #error
> so the build terminates if it is included directly.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---

How about we add a get_all_the_clks_for_the_device() sort of API
that uses the bulk clk code but also allocates the array by
reading the number of clks from DT? Please think of a better name
of course. We can figure out how to handle non-DT platforms if we
need to. With clkdev we could probably handle it with some sort
of lookup table search given a device name. Don't add that part
until we have a user though. I assume simplefb is all DT
platforms?

Either way, it looks like what we really want here is a way to
get every clk for a device and not look at the details. USB has a
similar case, which I think Shawn Guo/Dong Aisheng was trying to
add an OF based bulk clk_get() API called of_clk_bulk_get()
for[1]. If this get all clks API works there too then we should
use it. If it can be non-DT specific, even better.

[1] http://lkml.kernel.org/r/1506415441-4435-1-git-send-email-aisheng.dong@nxp.com

-- 
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a Linux Foundation Collaborative Project

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