Re: [PATCH v13 2/4] arm64: dts: fsl: librem5: Add a device tree for the Librem5 devkit

From: Angus Ainslie
Date: Fri May 24 2019 - 18:23:50 EST


Hi Pavel,

On 2019-05-24 15:00, Angus Ainslie wrote:
Hi Pavel,

On 2019-05-23 12:19, Pavel Machek wrote:
Hi!

- LEDs
- gyro
- magnetometer

+ leds {
+ compatible = "gpio-leds";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_gpio_leds>;
+
+ led1 {
+ label = "LED 1";

So, what kind of LED do you have, and what color is it? label should
probably be something like
notify:green.


As we don't have a specific use for these yet does it really matter if
there is a colour or a number associated with them ?

+ charger@6b { /* bq25896 */
+ compatible = "ti,bq25890";
+ reg = <0x6b>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_charger>;
+ interrupt-parent = <&gpio3>;
+ interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
+ ti,battery-regulation-voltage = <4192000>; /* 4.192V */
+ ti,charge-current = <1600000>; /* 1.6 A */

No space before A, for consistency.

+ ti,termination-current = <66000>; /* 66mA */
+ ti,precharge-current = <1300000>; /* 1.3A */

I thought precharge is usually something low, because you are not yet
sure of battery health...?


I think I put that in incorrectly. The intention was 130mA.

+ ti,minimum-sys-voltage = <2750000>; /* 2.75V */

Are you sure? Normally systems shut down at 3.2V, 3V or so. Li-ion
batteries don't
really like to be discharged _this_ deep.

You are correct. I'll fix it for the next version.


Looking into it further Sanyo and Panasonic get over 300 cycles bringing the NCR18650 down to 2.5V so 2.75V should be fine.

http://www.batteryonestop.com/baotongusa/products/datasheets/li-ion/SANYO-NCR18650B-3400mAh.pdf
https://industrial.panasonic.com/ww/products/batteries/secondary-batteries/lithium-ion/cylindrical-type/NCR18650PF

Angus

Thanks
Angus


Pavel