Hi Sakari, > https://hverkuil.home.xs4all.nl/spec/driver-api/camera-sensor.html Ok: "8.2.2. Devicetree The currently preferred way to achieve this is using assigned-clocks, assigned-clock-parents and assigned-clock-rates properties. See Documentation/devicetree/bindings/clock/clock-bindings.txt for more information. The driver then gets the frequency using clk_get_rate()." Let's see: Documentation/devicetree/bindings/clock/clock-bindings.txt: "==Assigned clock parents and rates== Some platforms may require initial configuration of default parent clocks and clock frequencies. Such a configuration can be specified in a device tree node through assigned-clocks, assigned-clock-parents and assigned-clock-rates properties. The assigned-clock-parents property should contain a list of parent clocks in the form of a phandle and clock specifier pair and the assigned-clock-rates property should contain a list of frequencies in Hz. Both these properties should correspond to the clocks listed in the assigned-clocks property." So I'm after "assigned-clock-rates", right? "Configuring a clock's parent and rate through the device node that consumes the clock can be done only for clocks that have a single user. Specifying conflicting parent or rate configuration in multiple consumer nodes for a shared clock is forbidden." This sounds a bit problematic, the clock I use is at least potentially shared by multiple parts of the system, depending on current (run time) configuration. I am/was getting different frequencies depending of the particular system (all based on the same i.MX6* SoC, but with different peripherals used/enabled). I think it's quite a common situation. > Generally camera sensor drivers that set the clock in drivers themselves > are (very) old. Let's have a look... ov9282 is (one of) the newest drivers. It does: #define OV9282_INCLK_RATE 24000000 /* Get sensor input clock */ ov9282->inclk = devm_clk_get(ov9282->dev, NULL); if (IS_ERR(ov9282->inclk)) { dev_err(ov9282->dev, "could not get inclk"); return PTR_ERR(ov9282->inclk); } rate = clk_get_rate(ov9282->inclk); if (rate != OV9282_INCLK_RATE) { dev_err(ov9282->dev, "inclk frequency mismatch"); return -EINVAL; } $ git grep -l ov9282 Documentation/devicetree/bindings/media/i2c/ovti,ov9282.yaml MAINTAINERS drivers/media/i2c/Kconfig drivers/media/i2c/Makefile drivers/media/i2c/ov9282.c clocks: description: Clock frequency from 6 to 27MHz No in-tree DTS exists, but the single frequency (both in the driver - this one can be fixed - and in the DTS) is rather limiting. Maybe another: imx412, imx335, imx334, imx258 - same here. imx208 is ACPI-based. Which driver should I consult? -- Krzysztof "Chris" Hałasa Sieć Badawcza Łukasiewicz Przemysłowy Instytut Automatyki i Pomiarów PIAP Al. Jerozolimskie 202, 02-486 Warszawa
