[PATCH 00/11] mfd: simple demodularization of non-modular drivers

[PATCH 00/11] mfd: simple demodularization of non-modular drivers

[Paul Gortmaker]

This group of MFD drivers are all controlled by "bool" Kconfig settings,
but contain traces of module infrastructure like unused/orphaned __exit
functions, use of <linux/module.h> and/or MODULE_ macros that are no-ops
in the non-modular case.

We can remove/replace all of the above.  We are trying to make driver
code consistent with the Makefiles/Kconfigs that control them.  This
means not using modular functions/macros for drivers that can never be
built as a module.  Some of the downfalls this leads to are:

 (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 drivers and spreads quickly.

The changes here should represent zero runtime changes.  Only the ones
with removed __exit functions will have a slightly smaller object size.
The source gets a net reduction of 100+ lines of unused code.

Build testing was done on drivers/mfd for allyesconfig on x86_64, ARM
and ARM-64.

Paul.

---

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Cory Maccarrone <darkstar6262@gmail.com>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Graeme Gregory <gg@slimlogic.co.uk>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Mattias Nilsson <mattias.i.nilsson@stericsson.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: patches@opensource.cirrus.com
Cc: Support Opensource <support.opensource@diasemi.com>

Paul Gortmaker (11):
  mfd: as3711: Make it explicitly non-modular
  mfd: da9055-core: make it explicitly non-modular
  mfd: db8500-prcmu: drop unused MODULE_ tags from non-modular code
  mfd: htc-i2cpld: Make it explicitly non-modular
  mfd: max8925-core: drop unused MODULE_ tags from non-modular code
  mfd: rc5t583: Make it explicitly non-modular
  mfd: sta2x11: drop unused MODULE_ tags from non-modular code
  mfd: syscon: Make it explicitly non-modular
  mfd: tps65910: Make it explicitly non-modular
  mfd: wm831x-core: drop unused MODULE_ tags from non-modular code
  mfd: wm8400-core: Make it explicitly non-modular

 drivers/mfd/as3711.c       | 14 --------------
 drivers/mfd/da9055-core.c  | 13 ++-----------
 drivers/mfd/db8500-prcmu.c | 10 ++++------
 drivers/mfd/htc-i2cpld.c   | 18 +-----------------
 drivers/mfd/max8925-core.c |  7 +------
 drivers/mfd/rc5t583.c      | 14 --------------
 drivers/mfd/sta2x11-mfd.c  | 10 ++++------
 drivers/mfd/syscon.c       | 12 +-----------
 drivers/mfd/tps65910.c     | 18 +-----------------
 drivers/mfd/wm831x-core.c  |  7 ++-----
 drivers/mfd/wm8400-core.c  | 18 +++---------------
 11 files changed, 19 insertions(+), 122 deletions(-)

-- 
2.7.4

[PATCH 09/11] mfd: tps65910: Make it explicitly non-modular

[Paul Gortmaker]

The Kconfig currently controlling compilation of this code is:

drivers/mfd/Kconfig:config MFD_TPS65910
drivers/mfd/Kconfig-    bool "TI TPS65910 Power Management chip"

...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.

Since module_init was not in use by this code, the init ordering
remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.
We do delete an unused moduleparam.h include though.

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

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Graeme Gregory <gg@slimlogic.co.uk>
Cc: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/mfd/tps65910.c | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
index bf16cbe6fd88..aa3d472a10ff 100644
--- a/drivers/mfd/tps65910.c
+++ b/drivers/mfd/tps65910.c
@@ -1,5 +1,5 @@
 /*
- * tps65910.c  --  TI TPS6591x
+ * tps65910.c  --  TI TPS6591x chip family multi-function driver
  *
  * Copyright 2010 Texas Instruments Inc.
  *
@@ -13,8 +13,6 @@
  *
  */
 
-#include <linux/module.h>
-#include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/slab.h>
@@ -374,7 +372,6 @@ static const struct of_device_id tps65910_of_match[] = {
 	{ .compatible = "ti,tps65911", .data = (void *)TPS65911},
 	{ },
 };
-MODULE_DEVICE_TABLE(of, tps65910_of_match);
 
 static struct tps65910_board *tps65910_parse_dt(struct i2c_client *client,
 						unsigned long *chip_id)
@@ -527,8 +524,6 @@ static const struct i2c_device_id tps65910_i2c_id[] = {
        { "tps65911", TPS65911 },
        { }
 };
-MODULE_DEVICE_TABLE(i2c, tps65910_i2c_id);
-
 
 static struct i2c_driver tps65910_i2c_driver = {
 	.driver = {
@@ -545,14 +540,3 @@ static int __init tps65910_i2c_init(void)
 }
 /* init early so consumer devices can complete system boot */
 subsys_initcall(tps65910_i2c_init);
-
-static void __exit tps65910_i2c_exit(void)
-{
-	i2c_del_driver(&tps65910_i2c_driver);
-}
-module_exit(tps65910_i2c_exit);
-
-MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
-MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
-MODULE_DESCRIPTION("TPS6591x chip family multi-function driver");
-MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [PATCH 09/11] mfd: tps65910: Make it explicitly non-modular

[Graeme Gregory]

On Thu, 22 Nov 2018, at 4:32 AM, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
> 
> drivers/mfd/Kconfig:config MFD_TPS65910
> drivers/mfd/Kconfig-    bool "TI TPS65910 Power Management chip"
> 
> ...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.
> 
> Since module_init was not in use by this code, the init ordering
> remains unchanged with this commit.
> 
> We don't replace module.h with init.h since the file already has that.
> We do delete an unused moduleparam.h include though.
> 
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
> 
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
> 
This is all fine with me.

Acked-by: Graeme Gregory <gg@slimlogic.co.uk>

Thanks

> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Graeme Gregory <gg@slimlogic.co.uk>
> Cc: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
> Cc: linux-omap@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  drivers/mfd/tps65910.c | 18 +-----------------
>  1 file changed, 1 insertion(+), 17 deletions(-)
> 
> diff --git a/drivers/mfd/tps65910.c b/drivers/mfd/tps65910.c
> index bf16cbe6fd88..aa3d472a10ff 100644
> --- a/drivers/mfd/tps65910.c
> +++ b/drivers/mfd/tps65910.c
> @@ -1,5 +1,5 @@
>  /*
> - * tps65910.c  --  TI TPS6591x
> + * tps65910.c  --  TI TPS6591x chip family multi-function driver
>   *
>   * Copyright 2010 Texas Instruments Inc.
>   *
> @@ -13,8 +13,6 @@
>   *
>   */
>  
> -#include <linux/module.h>
> -#include <linux/moduleparam.h>
>  #include <linux/init.h>
>  #include <linux/err.h>
>  #include <linux/slab.h>
> @@ -374,7 +372,6 @@ static const struct of_device_id tps65910_of_match[] = {
>  	{ .compatible = "ti,tps65911", .data = (void *)TPS65911},
>  	{ },
>  };
> -MODULE_DEVICE_TABLE(of, tps65910_of_match);
>  
>  static struct tps65910_board *tps65910_parse_dt(struct i2c_client *client,
>  						unsigned long *chip_id)
> @@ -527,8 +524,6 @@ static const struct i2c_device_id tps65910_i2c_id[] = {
>         { "tps65911", TPS65911 },
>         { }
>  };
> -MODULE_DEVICE_TABLE(i2c, tps65910_i2c_id);
> -
>  
>  static struct i2c_driver tps65910_i2c_driver = {
>  	.driver = {
> @@ -545,14 +540,3 @@ static int __init tps65910_i2c_init(void)
>  }
>  /* init early so consumer devices can complete system boot */
>  subsys_initcall(tps65910_i2c_init);
> -
> -static void __exit tps65910_i2c_exit(void)
> -{
> -	i2c_del_driver(&tps65910_i2c_driver);
> -}
> -module_exit(tps65910_i2c_exit);
> -
> -MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
> -MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>");
> -MODULE_DESCRIPTION("TPS6591x chip family multi-function driver");
> -MODULE_LICENSE("GPL");
> -- 
> 2.7.4
>