Messages in this thread |  | | | From | Pali Rohár <> | | Subject | Re: [PATCH] mfd: add bq2415x charger driver | | Date | Tue, 06 Dec 2011 14:34:59 +0100 |
| |
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] |  |