Re: [PATCH 1/3] pda_power: add support for writeable properties

[Daniel Mack <daniel@caiaq.de>]

Sorry for the resend guys. My clock was skewed again, which might cause
people missing the messages. Fixed some commit logs on the way.

Sent from a tired brain, excuse typos :)


On Fri, May 07, 2010 at 07:52:11PM +0200, Daniel Mack wrote:
> This patch adds support for writeable power supply properties and
> exposes them as writeable to sysfs.
> 
> A power supply implementation must implement two new function calls in
> order to use that feature:
> 
>   int set_property(struct power_supply *psy,
>                    enum power_supply_property psp,
>                    const union power_supply_propval *val);
> 
>   int property_is_writeable(struct power_supply *psy,
>                             enum power_supply_property psp);
> 
> Signed-off-by: Daniel Mack <daniel@caiaq.de>
> Cc: Anton Vorontsov <cbou@mail.ru>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Andres Salomon <dilinger@collabora.co.uk>
> Cc: Alexey Starikovskiy <astarikovskiy@suse.de>
> Cc: Len Brown <len.brown@intel.com>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Cc: Matt Reimer <mreimer@vpop.net>
> Cc: Evgeniy Polyakov <zbr@ioremap.net>
> Cc: Tejun Heo <tj@kernel.org>
> ---
>  drivers/power/power_supply_sysfs.c |   31 +++++++++++++++++++++++++++++--
>  include/linux/power_supply.h       |    5 +++++
>  2 files changed, 34 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
> index 5b6e352..5cfb410 100644
> --- a/drivers/power/power_supply_sysfs.c
> +++ b/drivers/power/power_supply_sysfs.c
> @@ -31,9 +31,9 @@
>  
>  #define POWER_SUPPLY_ATTR(_name)					\
>  {									\
> -	.attr = { .name = #_name, .mode = 0444 },	\
> +	.attr = { .name = #_name },					\
>  	.show = power_supply_show_property,				\
> -	.store = NULL,							\
> +	.store = power_supply_store_property,				\
>  }
>  
>  static struct device_attribute power_supply_attrs[];
> @@ -91,6 +91,25 @@ static ssize_t power_supply_show_property(struct device *dev,
>  	return sprintf(buf, "%d\n", value.intval);
>  }
>  
> +static ssize_t power_supply_store_property(struct device *dev,
> +					   struct device_attribute *attr,
> +					   const char *buf, size_t count) {
> +	ssize_t ret;
> +	struct power_supply *psy = dev_get_drvdata(dev);
> +	const ptrdiff_t off = attr - power_supply_attrs;
> +	union power_supply_propval value;
> +	long long_val;
> +
> +	/* TODO: support other types than int */
> +	ret = strict_strtol(buf, 10, &long_val);
> +	if (ret < 0)
> +		return ret;
> +
> +	value.intval = long_val;
> +
> +	return psy->set_property(psy, off, &value);
> +}
> +
>  /* Must be in the same order as POWER_SUPPLY_PROP_* */
>  static struct device_attribute power_supply_attrs[] = {
>  	/* Properties of type `int' */
> @@ -164,6 +183,14 @@ int power_supply_create_attrs(struct power_supply *psy)
>  	}
>  
>  	for (j = 0; j < psy->num_properties; j++) {
> +		mode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
> +
> +		if (psy->property_is_writeable &&
> +		    psy->property_is_writeable(psy, psy->properties[j]) > 0)
> +			mode |= S_IWUSR;
> +
> +		power_supply_attrs[psy->properties[j]].attr.mode = mode;
> +
>  		rc = device_create_file(psy->dev,
>  			    &power_supply_attrs[psy->properties[j]]);
>  		if (rc)
> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
> index ebd2b8f..f02f7fd 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -144,6 +144,11 @@ struct power_supply {
>  	int (*get_property)(struct power_supply *psy,
>  			    enum power_supply_property psp,
>  			    union power_supply_propval *val);
> +	int (*set_property)(struct power_supply *psy,
> +			    enum power_supply_property psp,
> +			    const union power_supply_propval *val);
> +	int (*property_is_writeable)(struct power_supply *psy,
> +				     enum power_supply_property psp);
>  	void (*external_power_changed)(struct power_supply *psy);
>  	void (*set_charged)(struct power_supply *psy);
>  
> -- 
> 1.6.3.3
>