[PATCH 00/10] clk: fix/remove module usage in non-modular code

[PATCH 00/10] clk: fix/remove module usage in non-modular code

[Paul Gortmaker]

This series covers the audit of non-modular module code use in the
drivers/clk/ directory.

Quasi generic boiler plate description follows; included for folks who
haven't yet seen what we are aiming to achieve with this operation.

We are trying to not use module support for code that can never be built
as a module because:

 (1) it is easy to accidentally write unused module_exit and remove code
 (2) it can be misleading when reading the source, thinking it can be
     modular when the Makefile and/or Kconfig prohibit it
 (3) it requires the include of the module.h header file which in turn
     includes nearly everything else, thus adding to CPP overhead.
 (4) it gets copied/replicated into other code and spreads like weeds.

With respect to #1 in this instance, we see for these 10 commits:
    15 files changed, 37 insertions(+), 227 deletions(-)
...which is a respectable (IMHO) net amount of removal of unused code.

Changes seen here cover the following categories:

  -just replacement of modular macros with their non-modular
   equivalents that CPP would have inserted anyway, such as:
	module_init --> device_initcall
	module_platform_driver --> builtin_platform_driver

  -the removal of including module.h ; replaced with init.h
   as required based on whether the file used it.

  -the removal of any/all unused/orphaned __exit functions that
   would never be called.

  -the removal of instances of MODULE_DEVICE_TABLE and MODULE_ALIAS
   that become no-ops in the non-modular case.

  -the removal of any ".remove" functions that were hooked into
   the driver struct.   This ".remove" function would of
   course not be called from the __exit function since that was
   never run.  However in theory, someone could have triggered it
   via sysfs unbind, even though there isn't a sensible use case
   for doing so.  So to cover that possibility, we've also disabled
   sysfs unbind in the driver.

  -the removal of MODULE_DESCRIIPTION/AUTHOR/LICENSE tags that are
   also no-ops for non-modular ; we ensure the information in those
   tags is present in the top of file comments in each case.

There are no initcall level changes here; everything stays at the level
of initcall it was previously - either by not using modular versions to
begin with, or by using the builtin level equivalents.

As usual, we can consider making some of these tristate if an author
has strong feelings about extending support into the modular realm,
but I won't be able to run-time test any of that.

I batched the sunxi changes together since they had similar author
and maintainer fields and it helps avoid polluting history with too
many mundane commits, but I can split that up if so desired.

Build testing done on linux-next on arm/arm64 and x86/x86_64.

Paul.
---

Cc: Aleksandr Frid <afrid@nvidia.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Padmavathi Venna <padma.v@samsung.com>
Cc: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>

Cc: linux-amlogic@lists.infradead.org
Cc: linux-clk@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-tegra@vger.kernel.org

Paul Gortmaker (10):
  clk: meson8b: make it explicitly non-modular
  clk: meson: make gxbb explicitly non-modular
  clk: mvebu: make cp110-system-controller explicitly non-modular
  clk: mvebu: make ap806-system-controller explicitly non-modular
  clk: oxnas: make it explicitly non-modular
  clk: samsung make clk-exynos-audss explicitly non-modular
  clk: samsung: make clk-s5pv210-audss explicitly non-modular
  clk: sunxi: make clk-* explicitly non-modular
  clk: tegra: make clk-tegra124-dfll-fcpu explicitly non-modular
  clk: ti: make clk-dra7-atl explicitly non-modular

 drivers/clk/clk-oxnas.c                     | 15 +++----------
 drivers/clk/meson/gxbb.c                    | 18 ++++-----------
 drivers/clk/meson/meson8b-clkc.c            | 19 ++++------------
 drivers/clk/mvebu/ap806-system-controller.c | 23 +++----------------
 drivers/clk/mvebu/cp110-system-controller.c | 34 +++--------------------------
 drivers/clk/samsung/clk-exynos-audss.c      | 13 +----------
 drivers/clk/samsung/clk-s5pv210-audss.c     | 29 ++----------------------
 drivers/clk/sunxi/clk-factors.c             |  1 -
 drivers/clk/sunxi/clk-sun6i-apb0-gates.c    |  9 ++------
 drivers/clk/sunxi/clk-sun6i-apb0.c          |  9 ++------
 drivers/clk/sunxi/clk-sun6i-ar100.c         | 21 +++---------------
 drivers/clk/sunxi/clk-sun8i-apb0.c          |  9 ++------
 drivers/clk/sunxi/clk-sun9i-mmc.c           | 28 +++---------------------
 drivers/clk/tegra/clk-tegra124-dfll-fcpu.c  | 16 ++------------
 drivers/clk/ti/clk-dra7-atl.c               | 20 +++--------------
 15 files changed, 37 insertions(+), 227 deletions(-)

-- 
2.8.4

[PATCH 10/10] clk: ti: make clk-dra7-atl explicitly non-modular

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

arch/arm/mach-omap2/Kconfig:config SOC_DRA7XX
arch/arm/mach-omap2/Kconfig:    bool "TI DRA7XX"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tags etc. since all that information
is already contained at the top of the file in the comments.

Cc: Tero Kristo <t-kristo@ti.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-omap@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/clk/ti/clk-dra7-atl.c | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/drivers/clk/ti/clk-dra7-atl.c b/drivers/clk/ti/clk-dra7-atl.c
index c77333230bdf..45d05339d583 100644
--- a/drivers/clk/ti/clk-dra7-atl.c
+++ b/drivers/clk/ti/clk-dra7-atl.c
@@ -15,7 +15,7 @@
  * GNU General Public License for more details.
  */
 
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/slab.h>
@@ -295,31 +295,17 @@ static int of_dra7_atl_clk_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int of_dra7_atl_clk_remove(struct platform_device *pdev)
-{
-	pm_runtime_disable(&pdev->dev);
-
-	return 0;
-}
-
 static const struct of_device_id of_dra7_atl_clk_match_tbl[] = {
 	{ .compatible = "ti,dra7-atl", },
 	{},
 };
-MODULE_DEVICE_TABLE(of, of_dra7_atl_clk_match_tbl);
 
 static struct platform_driver dra7_atl_clk_driver = {
 	.driver = {
 		.name = "dra7-atl",
+		.suppress_bind_attrs = true,
 		.of_match_table = of_dra7_atl_clk_match_tbl,
 	},
 	.probe = of_dra7_atl_clk_probe,
-	.remove = of_dra7_atl_clk_remove,
 };
-
-module_platform_driver(dra7_atl_clk_driver);
-
-MODULE_DESCRIPTION("Clock driver for DRA7 Audio Tracking Logic");
-MODULE_ALIAS("platform:dra7-atl-clock");
-MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
-MODULE_LICENSE("GPL v2");
+builtin_platform_driver(dra7_atl_clk_driver);
-- 
2.8.4

Re: [PATCH 10/10] clk: ti: make clk-dra7-atl explicitly non-modular

[Stephen Boyd]

On 07/04, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> arch/arm/mach-omap2/Kconfig:config SOC_DRA7XX
> arch/arm/mach-omap2/Kconfig:    bool "TI DRA7XX"
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
> 
> We explicitly disallow a driver unbind, since that doesn't have a
> sensible use case anyway, and it allows us to drop the ".remove"
> code for non-modular drivers.
> 
> Since module_platform_driver() uses the same init level priority as
> builtin_platform_driver() the init ordering remains unchanged with
> this commit.
> 
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
> 
> We also delete the MODULE_LICENSE tags etc. since all that information
> is already contained at the top of the file in the comments.
> 
> Cc: Tero Kristo <t-kristo@ti.com>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: linux-omap@vger.kernel.org
> Cc: linux-clk@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---

Applied to clk-next

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