Messages in this thread | | | Date | Tue, 17 Jun 2014 22:13:47 +0200 | From | Markus Pargmann <> | Subject | Re: [PATCH] regmap: Add Kconfig option for debugfs register writes |
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Hi,
On Tue, Jun 17, 2014 at 12:56:54PM -0700, David Rientjes wrote: > On Tue, 17 Jun 2014, Markus Pargmann wrote: > > > To enable writing of registers through the regmap debugfs interface, it > > was necessary to alter the regmap-debugfs.c source code. This is not > > really practical. > > > > As this is a powerful tool for debugging, this patch creates an expert > > kconfig option for this function. This makes it easier to enable > > register writing in the kernel. > > > > This patch also fixes the file mode when the regmap debugfs write code is > > compiled. > > > > Forcing users to enable CONFIG_EXPERT for this doesn't seem appropriate, > it enables things by default and has really become a separate config of > its own. You might want to consider removing this dependency unless you > have a strong reason for keeping it.
I only created the dependency on CONFIG_EXPERT to make it clear that this option is only for people who know what they are doing. I can remove that dependency if that is OK for everyone?
Thanks,
Markus
> > > Cc: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> > > Signed-off-by: Markus Pargmann <mpa@pengutronix.de> > > --- > > drivers/base/regmap/Kconfig | 14 ++++++++++++++ > > drivers/base/regmap/regmap-debugfs.c | 16 ++++++++++------ > > 2 files changed, 24 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig > > index 4251570610c9..ce86600dbe75 100644 > > --- a/drivers/base/regmap/Kconfig > > +++ b/drivers/base/regmap/Kconfig > > @@ -23,3 +23,17 @@ config REGMAP_MMIO > > > > config REGMAP_IRQ > > bool > > + > > +config REGMAP_ALLOW_WRITE_DEBUGFS > > + default n > > + depends on DEBUG_FS > > + depends on EXPERT > > + depends on REGMAP > > + bool "Regmap, allow direct register writes through debugfs" > > + help > > + This option enables regmap debugfs write support. If this is enabled, > > + you can directly write registers using the registers file in the > > + regmap debugfs. > > + > > + This is potentially dangerous. Do not enable this option unless you > > + know what you are doing. > > diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c > > index 45d812c0ea77..12906f2bdf00 100644 > > --- a/drivers/base/regmap/regmap-debugfs.c > > +++ b/drivers/base/regmap/regmap-debugfs.c > > @@ -261,13 +261,10 @@ static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, > > count, ppos); > > } > > > > -#undef REGMAP_ALLOW_WRITE_DEBUGFS > > -#ifdef REGMAP_ALLOW_WRITE_DEBUGFS > > +#if IS_ENABLED(CONFIG_REGMAP_ALLOW_WRITE_DEBUGFS) > > /* > > * This can be dangerous especially when we have clients such as > > - * PMICs, therefore don't provide any real compile time configuration option > > - * for this feature, people who want to use this will need to modify > > - * the source code directly. > > + * PMICs, therefore this function can only be selected in expert kconfig mode. > > */ > > static ssize_t regmap_map_write_file(struct file *file, > > const char __user *user_buf, > > @@ -512,7 +509,14 @@ void regmap_debugfs_init(struct regmap *map, const char *name) > > map, ®map_reg_ranges_fops); > > > > if (map->max_register || regmap_readable(map, 0)) { > > - debugfs_create_file("registers", 0400, map->debugfs, > > + unsigned int registers_mode; > > + > > + if (IS_ENABLED(CONFIG_REGMAP_ALLOW_WRITE_DEBUGFS)) > > + registers_mode = 0600; > > + else > > + registers_mode = 0400; > > + > > + debugfs_create_file("registers", registers_mode, map->debugfs, > > map, ®map_map_fops); > > debugfs_create_file("access", 0400, map->debugfs, > > map, ®map_access_fops); >
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