On Thu 2023-03-23 12:29:29, 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. hw can support 16mA -> you expose 0, 2mA, 4mA, 8mA, 16mA levels. hw can support 4mA -> you expose 0, 2mA, 4mA. Triggers will work with these. Best regards, Pavel -- People of Russia, stop Putin before his war on Ukraine escalates.
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