linux-kernel - [PATCH 0/3] ARM: convert from clk round_rate() to determine

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Message-Id: <20250710-arm32-clk-round-rate-v1-0-a9146b77aca9@redhat.com>
Date: Thu, 10 Jul 2025 19:42:15 -0400
From: Brian Masney <bmasney@...hat.com>
To: Paul Walmsley <paul@...an.com>, Aaro Koskinen <aaro.koskinen@....fi>, 
 Janusz Krzysztofik <jmkrzyszt@...il.com>, Tony Lindgren <tony@...mide.com>, 
 Russell King <linux@...linux.org.uk>, 
 Andreas Kemnade <andreas@...nade.info>, Kevin Hilman <khilman@...libre.com>, 
 Roger Quadros <rogerq@...nel.org>, Linus Walleij <linus.walleij@...aro.org>, 
 Liviu Dudau <liviu.dudau@....com>, Sudeep Holla <sudeep.holla@....com>, 
 Lorenzo Pieralisi <lpieralisi@...nel.org>, 
 Maxime Ripard <mripard@...nel.org>, Stephen Boyd <sboyd@...nel.org>
Cc: linux-clk@...r.kernel.org, linux-omap@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Brian Masney <bmasney@...hat.com>
Subject: [PATCH 0/3] ARM: convert from clk round_rate() to determine_rate()

The round_rate() clk ops is deprecated in the clk framework in favor
of the determine_rate() clk ops, so let's go ahead and convert the
drivers in the arm32 subsystem using the Coccinelle semantic patch
posted below. I did a few minor cosmetic cleanups of the code in a
few cases.

Coccinelle semantic patch:

    virtual patch

    // Look up the current name of the round_rate function
    @ has_round_rate @
    identifier round_rate_name =~ ".*_round_rate";
    identifier hw_param, rate_param, parent_rate_param;
    @@

    long round_rate_name(struct clk_hw *hw_param, unsigned long rate_param,
                  unsigned long *parent_rate_param)
    {
    	...
    }

    // Rename the route_rate function name to determine_rate()
    @ script:python generate_name depends on has_round_rate @
    round_rate_name << has_round_rate.round_rate_name;
    new_name;
    @@

    coccinelle.new_name = round_rate_name.replace("_round_rate", "_determine_rate")

    // Change rate to req->rate; also change occurrences of 'return XXX'.
    @ chg_rate depends on generate_name @
    identifier has_round_rate.round_rate_name;
    identifier has_round_rate.hw_param;
    identifier has_round_rate.rate_param;
    identifier has_round_rate.parent_rate_param;
    identifier ERR =~ "E.*";
    expression E;
    @@

    long round_rate_name(struct clk_hw *hw_param, unsigned long rate_param,
                  unsigned long *parent_rate_param)
    {
    <...
    (
    -return -ERR;
    +return -ERR;
    |
    - return rate_param;
    + return 0;
    |
    - return E;
    + req->rate = E;
    +
    + return 0;
    |
    - rate_param
    + req->rate
    )
    ...>
    }

    // Coccinelle only transforms the first occurrence of the rate parameter
    // Run a second time. FIXME: Is there a better way to do this?
    @ chg_rate2 depends on generate_name @
    identifier has_round_rate.round_rate_name;
    identifier has_round_rate.hw_param;
    identifier has_round_rate.rate_param;
    identifier has_round_rate.parent_rate_param;
    @@

    long round_rate_name(struct clk_hw *hw_param, unsigned long rate_param,
                  unsigned long *parent_rate_param)
    {
    <...
    - rate_param
    + req->rate
    ...>
    }

    // Change parent_rate to req->best_parent_rate
    @ chg_parent_rate depends on generate_name @
    identifier has_round_rate.round_rate_name;
    identifier has_round_rate.hw_param;
    identifier has_round_rate.rate_param;
    identifier has_round_rate.parent_rate_param;
    @@

    long round_rate_name(struct clk_hw *hw_param, unsigned long rate_param,
                  unsigned long *parent_rate_param)
    {
    <...
    (
    - *parent_rate_param
    + req->best_parent_rate
    |
    - parent_rate_param
    + &req->best_parent_rate
    )
    ...>
    }

    // Convert the function definition from round_rate() to determine_rate()
    @ func_definition depends on chg_rate @
    identifier has_round_rate.round_rate_name;
    identifier has_round_rate.hw_param;
    identifier has_round_rate.rate_param;
    identifier has_round_rate.parent_rate_param;
    identifier generate_name.new_name;
    @@

    - long round_rate_name(struct clk_hw *hw_param, unsigned long rate_param,
    -               unsigned long *parent_rate_param)
    + int new_name(struct clk_hw *hw, struct clk_rate_request *req)
    {
        ...
    }

    // Update the ops from round_rate() to determine_rate()
    @ ops depends on func_definition @
    identifier has_round_rate.round_rate_name;
    identifier generate_name.new_name;
    @@

    {
        ...,
    -   .round_rate = round_rate_name,
    +   .determine_rate = new_name,
        ...,
    }

Note that I used coccinelle 1.2 instead of 1.3 since the newer version
adds unnecessary braces as described in this post.
https://lore.kernel.org/cocci/67642477-5f3e-4b2a-914d-579a54f48cbd@intel.com/

Signed-off-by: Brian Masney <bmasney@...hat.com>
---
Brian Masney (3):
      ARM: OMAP1: clock: convert from round_rate() to determine_rate()
      ARM: OMAP2+: clock: convert from round_rate() to determine_rate()
      ARM: versatile: clock: convert from round_rate() to determine_rate()

 arch/arm/mach-omap1/clock.c                  | 19 +++++++++++++------
 arch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c | 12 +++++++-----
 arch/arm/mach-versatile/spc.c                |  9 +++++----
 3 files changed, 25 insertions(+), 15 deletions(-)
---
base-commit: b551c4e2a98a177a06148cf16505643cd2108386
change-id: 20250710-arm32-clk-round-rate-e52d845e682c

Best regards,
-- 
Brian Masney <bmasney@...hat.com>