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    SubjectRe: [PATCH] mfd: add bq2415x charger driver
    Date
    Hi,

    On Tuesday 06 December 2011 04:49:37 you wrote:
    > Hi,
    >
    > 2011/12/6 Sebastian Reichel <sre@debian.org>:
    > > Good to hear somebody is working on this :) I planned to do this
    > > myself, but didn't find any time for it. Here are some comments
    > :
    > > from me:
    > :)
    > :
    > > [...]
    > >
    > >> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
    > >
    > > I would expect the driver in drivers/power. But maybe MFD is
    > > better, since the chip can also be used to power USB host?

    Yes, chip support usb host mode and is working on rx51.

    >
    > Perhaps, at least I haven't tried that.
    >
    > > [...]
    > >
    > >> +#define BQ2415X_VOLTAGE_SCALE 20000
    > >
    > > If I remember correctly (I read the specs some time ago), this can
    > > be configured via external resistor. So this is board specific?
    >
    > Not really. There are 6 bits: 640, 320, 160, 80, 40, 20. So values
    > from 0 to 1260mV can be represented, at steps of 20mV. A value of 0
    > means 3.5V.
    >
    > > [...]
    > >
    > >> + bq2415x_i2c_write(cli, BQ2415X_CHG_CTL, 0x42);
    > >> + bq2415x_set_voltage(cli, 0, 4200000);
    > >> + bq2415x_set_current_limit(cli, 1800000, 1800000);
    > >
    > > So it always charges with 1.8A? Shouldn't this be dependent on the
    > > input source (e.g. 500mA from USB)? Also what's if no charger is
    > > connected at all?
    >
    > No. I'm hard-coding those values, but I wrote the functions
    > (set_voltate, set_current_limit) so all values are supported.

    These hardcoded values should go to board specified section.

    >
    > What is missing is the code to connect this driver to the charger
    > detector driver (isp1704), so those values are determined dynamically.
    >
    > > Apart from this I think those values should be exposed to sysfs
    > > via /sys/class/power_supply.
    >
    > Perhaps. Although I don't see much of the power supply interface that
    > could be useful here, but if so, I guess this should be indeed in
    > 'drivers/power'.

    Power supply interface has pending patches for chargers. Patches will add
    interface for periodic calling functions - which is usefull for watchdog reset
    and charging (+ errors handling).

    >
    > Cheers.

    --
    Pali Rohár
    pali.rohar@gmail.com[unhandled content-type:application/pgp-signature]
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