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Userspace driver and clocks

Question asked by Matthias Weisser on Apr 8, 2015
Latest reply on Apr 9, 2015 by igorpadykov



We have a special requirement regarding image processing which could be solved using the PXP. I wanted to write a user space IO driver to do this. My current problem is that the clock to the PXP is not enabled. I tried to use the uio_pdrv_genirq for the first tests and added the following device tree entry:


    pxp@02218000 {

        compatible = "gs-pxp";

        reg = <0x02218000 0x4000>;

        reg-names = "pxp"; /* Names of the zones */

        interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;

        clocks = <&clks IMX6SX_CLK_PXP_AXI>,

            <&clks IMX6SX_CLK_DISPLAY_AXI>;

        clock-names = "pxp-axi", "disp-axi";

        status = "okay";



The uio device is created correctly but when I open the device the clock in the CCM is not ungated. Do I have to do write my own uio kernel driver when clocks have to be enabled? Or is it possible to enable clocks from user space?