Hi Andy, On Tue, Jan 19, 2021 at 11:33:58AM +0200, Andy Shevchenko wrote: > On Tue, Jan 19, 2021 at 12:11:40AM +0000, Daniel Scally wrote: > > On 18/01/2021 21:19, Daniel Scally wrote: > > > > I'm more and more confident that this will work, but it has some > > knock-on effects: > > > > The both clk and regulator gpio driver expects to be able to fetch the > > GPIO using devm_gpiod_get(&pdev->dev, "enable", ...). That won't work of > > course, so we need to add another GPIO lookup table so those drivers can > > see the GPIOs. For that, we need to know what dev_name(&pdev->dev) will > > be so we can set the .dev_id member of a gpiod_lookup_table to that > > value, but that isn't set until _after_ the pdev is registered (because > > it has to figure out the id, we can't manually set the IDs because there > > could be more than one instance of int3472-discrete bound to multiple > > PMIC devices, and we don't know which id the current one should have). > > Finally, we can't wait until the device is registered because it > > immediately probes, can't find the GPIO and then fails probe. > > > > It's similar problem that causes us to need the i2c-acpi name format > > macros, but complicated by the dynamic ID part of dev_name(&pdev->dev) > > > > Solving it is a bit of a sticky one; perhaps something like moving the > > dev_set_name() part of platform_device_add() [1] to its own function, > > that's called in both platform_device_alloc() and > > platform_device_register(). That way it would be available before the > > device itself was registered, meaning we could create the lookup table > > before it probes the driver. > > See my previous reply. TL;DR: you have to modify clk-gpio.c to export couple of > methods to be able to use it as a library. That seems really overkill given the very simple implementation of the clock provided here. > > (also, Laurent, if we did it this way we wouldn't be able to also handle > > the led-indicator GPIO here without some fairly major rework) > > LED indicators are done as LED class devices (see plenty of examples in PDx86 > drivers: drivers/platform/x86/) How do you expose the link between the sensor and its indicator LED to userspace ? Isn't it better to handle it in the kernel to avoid rogue userspace turning the camera on without notifying the user ? -- Regards, Laurent Pinchart
