Hi,
On 17-05-16 19:41, Ene Alexandru wrote:
The AXP20X chips have a configuration register "REG 30H: VBUS-IPSOUT Power Path
Management" that provide USB power supply protection.
The current axp20x_usb_power.c provides support only for reading those values.
From the datasheet:
In order not to affect the USB communication, VBUS is always working under
Voltage-Limit mode by default. In this mode, AXP209 ensures that VBUS voltage
remains above a configurable reference voltage VHOLD which can meet the USB
specification. The default VHOLD is 4.4V, adjustable in Reg30H [5:3] register.
If the system has limit on current obtained from USB VBUS, a current-limit mode
is provided (See REG30H[1] register), with 900mA/500mA/100mA (Reg30H [0])
selectable.
The following entries are added in the axp209.dtsi file: vhold-enable,
vhold-set and ibus-limit
The chosen default values are the AXP20X reset values, as described in the data
sheet.
Signed-off-by: Ene Alexandru <[email protected]>
---
diff -uprN -X linux-sunxi-original/Documentation/dontdiff
linux-sunxi-original/arch/arm/boot/dts/axp209.dtsi
linux-sunxi/arch/arm/boot/dts/axp209.dtsi
--- linux-sunxi-original/arch/arm/boot/dts/axp209.dtsi 2016-05-11
09:21:47.470923679 +0200
+++ linux-sunxi/arch/arm/boot/dts/axp209.dtsi 2016-05-10 18:45:32.795158651
+0200
@@ -98,5 +98,8 @@
usb_power_supply: usb_power_supply {
compatible = "x-powers,axp202-usb-power-supply";
status = "disabled";
+ vhold-enable = <0x01>;
+ vhold-set = <0x04>;
+ ibus-limit = <0x01>;
};
};
Please do not use raw register values like this, instead make the device-tree
property take
microvolts / microamps like e.g. the regulator bindings do, and translate these
in the
driver.
Regards,
Hans
