@iabdalkader@pillo79@facchinm and others: As I have asked in issue#164 wondering best way to do this.

For example: currently it is setup like:

#if (defined(CONFIG_BOARD_ARDUINO_GIGA_R1) || defined(CONFIG_BOARD_ARDUINO_PORTENTA_H7)) \&& defined(CONFIG_VIDEO)#include <zephyr/kernel.h>#include <zephyr/device.h>#include <zephyr/drivers/clock_control.h>#include <zephyr/logging/log.h>int camera_ext_clock_enable(void){int ret;uint32_t rate;const struct device *cam_ext_clk_dev = DEVICE_DT_GET(DT_NODELABEL(pwmclock));if (!device_is_ready(cam_ext_clk_dev)) {return -ENODEV;}ret = clock_control_on(cam_ext_clk_dev, (clock_control_subsys_t)0);if (ret < 0) {return ret;}ret = clock_control_get_rate(cam_ext_clk_dev, (clock_control_subsys_t)0, &rate);if (ret < 0) {return ret;}return 0;}SYS_INIT(camera_ext_clock_enable, POST_KERNEL, CONFIG_CLOCK_CONTROL_PWM_INIT_PRIORITY);#endif

Note: this includes my one line change in this PR to enable it on Portenta H7.

But I keep wondering on ArduinoCore-zephyr, that Not all user sketches use Cameras, and yet we always start up
a clock pin running doing PWM. Could this not all be done within the Camera::begin(...) method?
That way only done if the sketch actually does anything with Cameras. Wondering if starting up resources like this
when they may or may not be applicable is a good thing. For example if your board is running off of a battery,
will this cause unnecessary power drain?

Also with this, maybe define some way to allow the sketch to specify which pins and/or which Carrier/Shield they
are using. For example: on the Portenta H7, they don't all use the same pin for the Clock (PA_8, PK_1). They use the same
timer. I know that OpenMV starts the timer ands sets both pins MUX(AF) to the timer. But again not sure in this
case we want to dedicate two pins for this as again not all sketches uses cameras.
But maybe if there was something like: myCamera.setShield(PORTENTA_VISION_SHIELD); it could set the
time pin and probably the Reset (actually the power on pin) and PWDN (not applicable)...

Thoughts?

Edit: Note: there currently is no approved way to actually access the PK_1 pin on Zephyr. Except if it is called out
somewhere within the overlay files. That is there is no Arduino Pin number associated with it, nor do we have
access by pin names.

Note: - I believe that my PR#195 is a better solution. It does not start the clocks until/if the sketch calls camera.begin

But to do this the cameras and DCIM need to be marked as defered init in the overlay, as to not have them try to initialize things
before the clock has been started. That PR updated both GIGA and H7 with the changes.