Hi,
This may be a fix that allows >0 input from DT, but won't try to program the register since the first 3 fields aren't compatible:
... bq27500_dm_regs[] = { ... [bq27xxx_dm_design_energy] = { 0, 0, 0, 0, 65535 }, /* missing on chip */ NB: align columns with other rows
Pls CC me on patch posts. You left me off your last series.
Cpl more comments below...
On Thu, Aug 31, 2017 at 2:35 AM, H. Nikolaus Schaller hns@goldelico.com wrote:
Hi Liam,
Am 31.08.2017 um 10:58 schrieb Liam Breck liam@networkimprov.net:
On Wed, Aug 30, 2017 at 11:58 PM, H. Nikolaus Schaller hns@goldelico.com wrote:
Hi Liam,
Am 30.08.2017 um 13:24 schrieb Liam Breck liam@networkimprov.net:
Hi Nikolaus,
On Wed, Aug 30, 2017 at 2:30 AM, H. Nikolaus Schaller hns@goldelico.com wrote:
Hi Liam and Sebastian,
Am 29.08.2017 um 22:20 schrieb Liam Breck liam@networkimprov.net:
Hi Nikolaus, thanks for the patch...
On Tue, Aug 29, 2017 at 1:10 PM, H. Nikolaus Schaller hns@goldelico.com wrote: > Tested on Pyra prototype with bq27421. > > Signed-off-by: H. Nikolaus Schaller hns@goldelico.com > --- > drivers/power/supply/bq27xxx_battery.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c > index b6c3120ca5ad..e3c878ef7c7e 100644 > --- a/drivers/power/supply/bq27xxx_battery.c > +++ b/drivers/power/supply/bq27xxx_battery.c > @@ -688,7 +688,7 @@ static struct bq27xxx_dm_reg bq27545_dm_regs[] = { > #define bq27545_dm_regs 0 > #endif > > -#if 0 /* not yet tested */ > +#if 1 /* tested on Pyra */ > static struct bq27xxx_dm_reg bq27421_dm_regs[] = {
I think we can drop the #if and #else...#endif so it's just the dm_regs table, as with bq27425.
I have fixed that and did take the chance to update my OpenPandora kernel so that I also could test and make the bq27500 working.
Is this gauge on the board or in the battery?
It is on the board.
If in the battery, monitored-battery should not be used.
For a gauge on the board, if a user changes the battery to a different type, they need to update the dtb.
Well, that is a little difficult to control, but here we have only one standard Pandora cell. There may exist replacements with different capacity, but that should not be our problem...
I assume you built with config_battery_bq27xxx_dt_updates_nvm?
Yes.
The biggest hurdle was to find out that I have to change the compatible string to "ti,bq27500-1" to get non-NULL dm_regs...
[ 12.765930] bq27xxx_battery_i2c_probe name=bq27500-1-0 [ 12.771392] bq27xxx_battery_i2c_probe call setup [ 12.874816] bq27xxx_battery_setup [ 12.904266] bq27xxx_battery_setup: dm_regs=bf0520e0 [ 12.933380] (NULL device *): hwmon: 'bq27500-1-0' is not a valid name attribute, please fix [ 13.234893] bq27xxx_battery_settings [ 13.238891] bq27xxx-battery 2-0055: invalid battery:energy-full-design-microwatt-hours 14800000
The chip does not support this param, so it should be zero, as it has to be set if charge-full-design-* is set. Can you try that?
Hm. IMHO the DT should describe what the battery has and the driver should simply ignore values it can't handle or reject them but do the best out of it. Telling the driver to ignore a value by setting to 0 would IMHO be the wrong approach.
The driver requires that if either charge- or energy-full-design is set, then the other must be. Setting one and leaving the other at default would be an error. Allowing any value for a field unsupported by the chip, when supported field values must be within a range, isn't useful for hw development or production scenarios. The solution for shipped equipment is to drop the monitored-battery ref; see below.
We are also working on the generic-adc-battery driver that makes use of the same battery DT node so that people can choose if they want to configure a kernel for fuel gauge or g-a-b or even both.
[ 13.312469] bq27xxx_battery_set_config [ 13.407745] bq27xxx_battery_unseal [ 13.455993] bq27xxx_battery_update_dm_block [ 13.460418] bq27xxx-battery 2-0055: update terminate-voltage to 3200 [ 13.694885] bq27xxx_battery_seal
We need to see output after a reboot.
This was the value after first boot with the new driver enabled.
A second boot after removing and reinserting battery shows:
[ 11.256713] bq27xxx_battery_setup [ 11.256744] bq27xxx_battery_setup: dm_regs=bf05b0e0 [ 11.257690] (NULL device *): hwmon: 'bq27500-1-0' is not a valid name attribute, please fix [ 11.258056] bq27xxx_battery_settings [ 11.258300] bq27xxx-battery 2-0055: invalid battery:energy-full-design-microwatt-hours 14800000 [ 11.258300] bq27xxx_battery_set_config [ 11.258331] bq27xxx_battery_unseal
No mention of terminate-voltage in that run?
No, I didn't see it again.
In the previous run terminate-voltage appeared after battery_unseal. Did you dmesg | grep bq27 ?
Or is this truncated? Looks like you didn't set energy-* to zero, so I can't tell if charge-* works.
Seems to need more experimentation (and more time for it).
Note that this chip has NVM so these settings persist without power.
Yes I know. Up to now the bq27500 has been programmed during production test by some special flashing tool. Now as the kernel driver has this capability, we should make (optionally) use of it.
The kernel driver has this feature primarily for gauges that lack NVM. It sets those without config_battery_bq27xxx_dt_updates_nvm. The NVM programming feature is for hw development and/or production. I don't recommend it for shipped equipment.
Mostly agreed...
Does this look ok for
bat: battery { compatible = "simple-battery", "openpandora-battery"; voltage-min-design-microvolt = <3200000>; energy-full-design-microwatt-hours = <14800000>; charge-full-design-microamp-hours = <4000000>; };?
I mainly had some initial doubts that it did not tell something like "update design-capacity" to 4000 or "design-capacity has 4000"
Ah, I see:
/* assume design energy & capacity are in same block */This means the bq27500 never programs capacity because we can't specify energy. So I't suggest to revise this rule and coupling of energy and capacity setting.
No, it failed to set charge-* because energy-* is out of range. Fix that and it should just emit a warning about energy-* "buffer does not match dm spec"
Here I strongly disagree. The DT property should describe the battery and not a limitation of the fuel gauge chip or the value is not in the range of what the chip expects.
IMHO, if the fuel gauge driver can't handle, it should not require to tamper with the battery DT description making it wrong and unuseable for other purposes.
You are right that we use DT:battery as config for the case of NVM hw development/manufacture (requiring custom kernel build). It is expedient since we have DT inputs for non-NVM chips.
But upstream dts cannot use monitored-battery to program NVM chips, as it won't (ever) work on normal kernels. You can argue that monitored-battery should cause a warning if an NVM chip has different settings, and we do that!
I will send a patch for enabling both fuel gauges and the omap3-pandora-common.dtsi asap.
You probably don't want this in upstream dts, as it only programs the gauge if the kernel has the above config option. If the box runs a stock distro, it won't work. A custom-built kernel with the above dts programs the gauge unless the user sets the module param dt_monitored_battery_updates_nvm=0. The requisite dtb should be packaged with the custom-built kernel, and deployed with awareness of the actual battery present.
Imho, DT can and should describe all properties of the standard OpenPandora battery (and not missing registers of the bq27500).
Using this information or not should be defined by different defconfigs.
Just omit monitored-battery from the bq27500 node on shipped devices. We shall not program NVM on a stock kernel. And unfortunately you can't send an NVM gauge temporary params.
Isn't this what the defconfigs are for?
A stock kernel should keep CONFIG_BATTERY_BQ27XXX_DT_UPDATES_NVM disabled and I haven't seen that it is enabled in a stock defconfig.
A production kernel (or user wanting to play with it) can enable. But should not change the DTB.
Where I previously said "for hw development/production" the latter term means manufacture, ie a kernel for use on assembly line for config/test. config...dt_updates_nvm shall not be set in a defconfig, distro, or shipped hw.
I have done the same mistake to mis-use DT as "configuration" or ask users to install different DTB several times myself and was heavily criticized, because maintainers clearly said DT should *describe* hardware and not configure kernel features. I.e. there should be only one DTB for each board.
Hence I would expect them to say: if the bq27500 monitors the battery it should be described by the DT. And if the battery has some energy-full-design-microwatt-hours, it should be there and not a "0" or omission.
But that is just *my* 2ct. DT maintainers should finally say something.
NB: the DT battery node is new and all the implications have not been discovered.
This BQ27 feature was begun in December of last year, and I'm a little tired of thinking about it.
I fully understand :) I have some patches in tiresome discussion since ca. 3 years...
Feel free to suggest improvements, but be aware that we might have already considered and rejected them :-)
We had observed this issue for the RAM only fuel gauge bq27421 a while ago (I think even before December) and had started our own patch set. Grazvydas recently had made it working on some older kernel which is now superseded by your patch set. So you were faster in submitting a solution (and yours is even more general than what we had ever thought about).
So I am very pleased with that we have a big step forward for the bq27421 based device. Making the bq27500 in the OpenPandora fool proof isn't that important for the moment so we can postpone it.
BR and thanks for all the work,
Feel free to send me a Pyra prototype or first-production unit :-) We're also working on an omap device, tho not a "handheld"