On Thu, Jul 24, 2025 at 02:20:10PM +0000, Tarang Raval wrote: > > > > > 2. In the regulator code, you can reduce boilerplate by using > > > > > devm_regulator_bulk_get_enable(). > > > > > > > > devm_regulator_bulk_get_enable() doesn't seem to be a good idea. You > > > > generally don't want to enable power everywhere unconditionally, and > > > > sensors very often need a guaranteed power up sequence. > > > > > > The regulators are optional, we supply power to the camera sensor directly > > > through dedicated power rails and there is no strict enable sequence > > > required in this case. > > > > What exactly do you mean by "this case" ? Are you talking about one > > particular sensor ? One particular camera module ? > > Laurent, by “this case” I meant the common scenario where power to the > camera sensor is supplied by a PMIC regulator that is always-on. In such > setups, the regulator is fixed and cannot be enabled or disabled from the > driver, the sensor is always powered. > > This is what I’ve seen in most platforms, where the CSI input connector > provides fixed 3.3V/1.8V power rails directly to the camera module. > > Of course, if the camera supply comes from a dedicated regulator controlled > via a GPIO, then the driver would need to handle enable/disable sequencing > explicitly. But I’m specifically referring to the first case, where the power rails > are always-on. How does the sensor driver know which of those two cases it is dealing with ? > Mark, depending on the hardware, the power rails could come either from a > PMIC or from a regulator controlled by GPIO, but I’m talking about the always-on > PMIC case here. -- Regards, Laurent Pinchart
