Messages in this thread | | | Date | Tue, 17 Jun 2014 12:56:54 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [PATCH] regmap: Add Kconfig option for debugfs register writes |
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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.
> 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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