Messages in this thread | | | From | Pali Rohár <> | Date | Tue, 1 Nov 2011 13:23:40 +0100 | Subject | Re: [PATCH 8/9] bq27x00: Add miscdevice for each battery with ioctl for reading registers |
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2011/11/1 Lars-Peter Clausen <lars@metafoo.de>: > On 11/01/2011 01:43 AM, Pali Rohár wrote: >> * When bq27x00_battery module is loaded it take control of bq27200 i2c battery chip and then it is not possible to use i2cget program from user space (returns -EBUSY) >> * This patch adds new miscdevice for each battery which has ioctl BQ27X00_READ_REG for reading battery registers from user space >> >> * ioctl cmd: >> #define BQ27X00_READ_REG _IO(MISC_MAJOR, 0) >> >> * ioctl arg: >> struct bq27x00_reg_parms { >> int reg; /* battery register (in) */ >> int single; /* 1 - 8bit register, 0 - 16bit register (in) */ >> int ret; /* register status, negative indicate error (out) */ >> }; >> >> Signed-off-by: Pali Rohár <pali.rohar@gmail.com> > > I'm not sure if this is such a good idea. Why do you need to read the registers > from userspace? Shouldn't all relevant information be available in a > standardized format through the power_supply userspace API? If you want to use > it for debugging it might be a better idea to provide a debugfs file. > > - Lars >
bq27200 chip has a lot of registers (for diagnostic) which is usefull on Nokia N900. power_supply interface is not very abstract to handle all of them. Also on Nokia N900 is needed proprietary pogram BME for battery charging which need to access to bq27200 registers. A simple LD_PRELOAD library which wrap i2c-dev access to this device provided by this patch is here: https://code.launchpad.net/~pali/+junk/maemo_libbqioctl
Other shell script which show all info from bq register is here: http://enivax.net/jk/n900/bq.tar
-- Pali Rohár pali.rohar@gmail.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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