Re: [PATCH 2/3] power: supply: cpcap-battery: Fix battery identification

[Ivaylo Dimitrov]

Hi,

On 10.11.22 г. 18:05 ч., Sebastian Reichel wrote:
> Hi,
>
> On Sat, Nov 05, 2022 at 01:25:43PM +0200, Ivaylo Dimitrov wrote:
> > Use the same logic to identify genuine batteries as Android does.
> >
> > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
> > ---
>
> Why do we care?

Because if we know the battery is genuine (or at least pretends to be :) 
), then we can read battery parameters from nvram, see patch 3/3. This 
will allow us to charge HV LiPo batteries to 4.35V, using the full capacity.

Not to say the code currently identifies a specific battery with id of 
"89-500029ba0f73" as genuine one, ignoring all others. So this patch is 
more or less a bugfix too.

Regards,
Ivo


> -- Sebastian
>
> >   drivers/power/supply/cpcap-battery.c | 19 ++++++++++++++-----
> >   1 file changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c
> > index 8869067..ca6ee2b 100644
> > --- a/drivers/power/supply/cpcap-battery.c
> > +++ b/drivers/power/supply/cpcap-battery.c
> > @@ -422,7 +422,7 @@ static int cpcap_battery_cc_to_ua(struct cpcap_battery_ddata *ddata,
> >   
> >   static int cpcap_battery_match_nvmem(struct device *dev, const void *data)
> >   {
> > -	if (strcmp(dev_name(dev), "89-500029ba0f73") == 0)
> > +	if (strncmp(dev_name(dev), "89-500", 6) == 0)
> >   		return 1;
> >   	else
> >   		return 0;
> > @@ -439,10 +439,19 @@ static void cpcap_battery_detect_battery_type(struct cpcap_battery_ddata *ddata)
> >   	if (IS_ERR_OR_NULL(nvmem)) {
> >   		ddata->check_nvmem = true;
> >   		dev_info_once(ddata->dev, "Can not find battery nvmem device. Assuming generic lipo battery\n");
> > -	} else if (nvmem_device_read(nvmem, 2, 1, &battery_id) < 0) {
> > -		battery_id = 0;
> > -		ddata->check_nvmem = true;
> > -		dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
> > +	} else {
> > +		char buf[24];
> > +
> > +		if (nvmem_device_read(nvmem, 96, 4, buf) < 0 ||
> > +		    strncmp(buf, "COPR", 4) != 0 ||
> > +		    nvmem_device_read(nvmem, 104, 24, buf) < 0 ||
> > +		    strncmp(buf, "MOTOROLA E.P CHARGE ONLY", 24) != 0 ||
> > +		    nvmem_device_read(nvmem, 2, 1, &battery_id) < 0) {
> > +			battery_id = 0;
> > +			ddata->check_nvmem = true;
> > +			dev_warn(ddata->dev, "Can not read battery nvmem device. Assuming generic lipo battery\n");
> > +		}
> > +
> >   	}
> >   
> >   	switch (battery_id) {
> > --
> > 1.9.1