On Sat, Jan 19, 2013 at 03:01:43PM +0100, Pali Rohár wrote: > bq27xxx batteries have a lot of properties, more than power_supply interface. > Some of them can be usefull for userspace applications (like CI bit) but > does not make sense to add bq specified property to power_supply interface. > When bq27x00_battery is not loaded userspace application (like i2cget) can > use /dev/i2c-* interface for raw access. But when kernel module is attached > to i2c device, userspace applications cannot access it via /dev/i2c-*. > Also it is not usefull for userspace to unload module before reading values > form /dev/i2c-* and then load it again.
If it is useful for userspace applications, you probably do want to make a proper interface for it? What is "CI" bit? We were discussing it before, right? http://permalink.gmane.org/gmane.linux.kernel/1220570 I said: In any case, I just think that being able to access already bound I2C devices from userspace might be a good thing for debugging, but having such an interface per-driver is impractical. So, I still think that making a generic interface is the way to go. And Mark Brown said: if this is a device that has registers that fit within regmap then the regmap API provides a debugfs interface for dumping the register map as standard. ... The regmap debug file is a file of lines in the format 'regnum: value' where both fields have a fixed width so should be easily parsable. So, it seems that we have that interface already. Here is the whole discussion: http://comments.gmane.org/gmane.linux.kernel/1209421 Thanks, > This patch exporting all battery registers to sysfs entry "registers" in > battery power_supply directory. Format is "register=value" on separate line. > Because length of registers are different for each bq battery more for loops > are needed. > > Signed-off-by: Pali Rohár <[email protected]> > --- > drivers/power/bq27x00_battery.c | 98 > +++++++++++++++++++++++++++++++++++++-- > 1 file changed, 95 insertions(+), 3 deletions(-) > > diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c > index 7087d0d..af0f68f 100644 > --- a/drivers/power/bq27x00_battery.c > +++ b/drivers/power/bq27x00_battery.c > @@ -690,6 +690,90 @@ static void bq27x00_external_power_changed(struct > power_supply *psy) > schedule_delayed_work(&di->work, 0); > } > > +/* code for register device access via sysfs */ > + > +static ssize_t bq27x00_battery_sysfs_print_reg(struct bq27x00_device_info > *di, > + u8 reg, bool single, char *buf) > +{ > + int ret = bq27x00_read(di, reg, single); > + if (ret < 0) > + return sprintf(buf, "%#.2x=error %d\n", reg, ret); > + else > + return sprintf(buf, "%#.2x=%#.2x\n", reg, ret); > +} > + > +static ssize_t bq27x00_battery_sysfs_show_registers(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct power_supply *psy = dev_get_drvdata(dev); > + struct bq27x00_device_info *di = container_of(psy, > + struct bq27x00_device_info, > + bat); > + u8 reg; > + ssize_t ret = 0; > + > + switch (di->chip) { > + > + case BQ27000: > + for (reg=0x00; reg<=0x01; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + for (reg=0x02; reg<=0x08; reg+=2) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, false, > buf+ret); > + for (reg=0x0A; reg<=0x0B; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + for (reg=0x0C; reg<=0x2A; reg+=2) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, false, > buf+ret); > + for (reg=0x2C; reg<=0x7F; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + break; > + > + case BQ27500: > + for (reg=0x00; reg<=0x2C; reg+=2) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, false, > buf+ret); > + for (reg=0x2E; reg<=0x3B; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + for (reg=0x3C; reg<=0x3C; reg+=2) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, false, > buf+ret); > + for (reg=0x3E; reg<=0x7F; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + break; > + > + case BQ27425: > + for (reg=0x00; reg<=0x3C; reg+=2) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, false, > buf+ret); > + for (reg=0x3E; reg<=0x7F; reg+=1) > + ret += bq27x00_battery_sysfs_print_reg(di, reg, true, > buf+ret); > + break; > + > + } > + > + return ret; > +} > + > +static DEVICE_ATTR(registers, S_IRUGO, > + bq27x00_battery_sysfs_show_registers, NULL); > + > +static struct attribute *bq27x00_battery_sysfs_attributes[] = { > + &dev_attr_registers.attr, > + NULL, > +}; > + > +static const struct attribute_group bq27x00_battery_sysfs_attr_group = { > + .attrs = bq27x00_battery_sysfs_attributes, > +}; > + > +static int bq27x00_battery_sysfs_init(struct bq27x00_device_info *di) > +{ > + return sysfs_create_group(&di->bat.dev->kobj, > + &bq27x00_battery_sysfs_attr_group); > +} > + > +static void bq27x00_battery_sysfs_exit(struct bq27x00_device_info *di) > +{ > + sysfs_remove_group(&di->bat.dev->kobj, > + &bq27x00_battery_sysfs_attr_group); > +} > + > static int bq27x00_powersupply_init(struct bq27x00_device_info *di) > { > int ret; > @@ -705,15 +789,22 @@ static int bq27x00_powersupply_init(struct > bq27x00_device_info *di) > di->bat.get_property = bq27x00_battery_get_property; > di->bat.external_power_changed = bq27x00_external_power_changed; > > - INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll); > - mutex_init(&di->lock); > - > ret = power_supply_register(di->dev, &di->bat); > if (ret) { > dev_err(di->dev, "failed to register battery: %d\n", ret); > return ret; > } > > + ret = bq27x00_battery_sysfs_init(di); > + if (ret) { > + dev_err(di->dev, "failed to register battery: %d\n", ret); > + power_supply_unregister(&di->bat); > + return ret; > + } > + > + INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll); > + mutex_init(&di->lock); > + > dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION); > > bq27x00_update(di); > @@ -733,6 +824,7 @@ static void bq27x00_powersupply_unregister(struct > bq27x00_device_info *di) > > cancel_delayed_work_sync(&di->work); > > + bq27x00_battery_sysfs_exit(di); > power_supply_unregister(&di->bat); > > mutex_destroy(&di->lock); > -- > 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
