Messages in this thread | | | Date | Tue, 6 Dec 2011 04:49:37 +0200 | Subject | Re: [PATCH] mfd: add bq2415x charger driver | From | Felipe Contreras <> |
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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?
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.
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'.
Cheers.
-- Felipe Contreras -- 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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