Hi, On 3/23/23 12:29, Hans de Goede wrote: > Hi, > > On 3/23/23 12:26, Pavel Machek wrote: >> On Thu 2023-03-23 12:24:05, Hans de Goede wrote: >>> Hi Pavel, >>> >>> On 3/23/23 12:15, Pavel Machek wrote: >>>> Hi! >>>> >>>>> There are two LED controllers, LEDA indicator LED and LEDB flash LED for >>>>> tps68470. LEDA can be enabled by setting TPS68470_ILEDCTL_ENA. Moreover, >>>>> tps68470 provides four levels of power status for LEDB. If the >>>>> properties called "ti,ledb-current" can be found, the current will be >>>>> set according to the property values. These two LEDs can be controlled >>>>> through the LED class of sysfs (tps68470-leda and tps68470-ledb). >>>> >>>> If the LED can have four different currents, should it have 4 >>>> brightness levels? >>> >>> No this was already discussed with an earlier version. This is in >>> indicator LED output. The current setting is a one time boot configure >>> thing after which the indicator LED is either on or off. >> >> Current levels are exponential in that driver. That will result in >> rather nice four level. Surely LED does not care if you set it during >> boot or later? > > Well for one there is no guarantee the LED can continuously handle > the maximum configurable LED current and as you rightly point out > elsewhere in the thread we don't want to be blowing up hw. Also this LED output as mentioned is especially intended for use with on/off triggers and those don't use/set different brightness levels. So it really is best to set the LED current once to the current which we want when the LED is on to indicate whatever it is intended to be indicating. Regards, Hans
