linux-kernel - [PATCH 0/9] drm: convert from clk round_rate() to determine

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Message-Id: <20250710-drm-clk-round-rate-v1-0-601b9ea384c3@redhat.com>
Date: Thu, 10 Jul 2025 13:43:01 -0400
From: Brian Masney <bmasney@...hat.com>
To: Philipp Zabel <p.zabel@...gutronix.de>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, 
 Linus Walleij <linus.walleij@...aro.org>, 
 Rob Clark <robin.clark@....qualcomm.com>, 
 Dmitry Baryshkov <lumag@...nel.org>, 
 Abhinav Kumar <abhinav.kumar@...ux.dev>, 
 Jessica Zhang <jessica.zhang@....qualcomm.com>, Sean Paul <sean@...rly.run>, 
 Marijn Suijten <marijn.suijten@...ainline.org>, 
 Yannick Fertre <yannick.fertre@...s.st.com>, 
 Raphael Gallais-Pou <raphael.gallais-pou@...s.st.com>, 
 Philippe Cornu <philippe.cornu@...s.st.com>, 
 Maxime Coquelin <mcoquelin.stm32@...il.com>, 
 Alexandre Torgue <alexandre.torgue@...s.st.com>, 
 Chen-Yu Tsai <wens@...e.org>, Jernej Skrabec <jernej.skrabec@...il.com>, 
 Samuel Holland <samuel@...lland.org>, Stephen Boyd <sboyd@...nel.org>
Cc: dri-devel@...ts.freedesktop.org, imx@...ts.linux.dev, 
 linux-clk@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org, 
 freedreno@...ts.freedesktop.org, linux-stm32@...md-mailman.stormreply.com, 
 linux-sunxi@...ts.linux.dev, Brian Masney <bmasney@...hat.com>
Subject: [PATCH 0/9] drm: 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 drm 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 (9):
      drm/imx/ipuv3/imx-tve: convert from round_rate() to determine_rate()
      drm/mcde/mcde_clk_div: convert from round_rate() to determine_rate()
      drm/msm/disp/mdp4/mdp4_lvds_pll: convert from round_rate() to determine_rate()
      drm/msm/hdmi_pll_8960: convert from round_rate() to determine_rate()
      drm/pl111: convert from round_rate() to determine_rate()
      drm/stm/dw_mipi_dsi-stm: convert from round_rate() to determine_rate()
      drm/stm/lvds: convert from round_rate() to determine_rate()
      drm/sun4i/sun4i_hdmi_ddc_clk: convert from round_rate() to determine_rate()
      drm/sun4i/sun4i_tcon_dclk: convert from round_rate() to determine_rate()

 drivers/gpu/drm/imx/ipuv3/imx-tve.c           | 17 ++++++++++-------
 drivers/gpu/drm/mcde/mcde_clk_div.c           | 13 ++++++++-----
 drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c | 13 ++++++++-----
 drivers/gpu/drm/msm/hdmi/hdmi_pll_8960.c      | 12 +++++++-----
 drivers/gpu/drm/pl111/pl111_display.c         | 13 ++++++++-----
 drivers/gpu/drm/stm/dw_mipi_dsi-stm.c         | 14 ++++++++------
 drivers/gpu/drm/stm/lvds.c                    | 12 +++++++-----
 drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c    | 12 +++++++-----
 drivers/gpu/drm/sun4i/sun4i_tcon_dclk.c       | 18 ++++++++++--------
 9 files changed, 73 insertions(+), 51 deletions(-)
---
base-commit: b551c4e2a98a177a06148cf16505643cd2108386
change-id: 20250710-drm-clk-round-rate-b25099c0c3a7

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