Hey Moritz-
On Fri, Oct 16, 2015 at 03:42:30PM -0700, Moritz Fischer wrote:
> This commit adds FPGA Manager support for the Xilinx Zynq chip.
> The code borrows some from the xdevcfg driver in Xilinx'
> vendor tree.
>
> Signed-off-by: Moritz Fischer <moritz.fischer@xxxxxxxxx>
> ---
>
> v2:
> - Replaced locking error flag and broken completion with irq masking
> and changed completion handling
> - Dealing with timeout cases
> - Reworked clock handling
> - Moved initialization from probe() to write_init()
> - Fixed return value of devm_request_irq() check to check for non-zero
> - Alphabetized includes ;-)
> - Changed some of the comments, to better explain what's happening
[..]
> +static int zynq_fpga_probe(struct platform_device *pdev)
> +{
[..]
> + priv->clk = devm_clk_get(dev, "ref_clk");
> + if (IS_ERR(priv->clk)) {
> + dev_err(dev, "input clock not found");
> + return PTR_ERR(priv->clk);
> + }
> +
> + err = clk_prepare_enable(priv->clk);
> + if (err) {
> + dev_err(dev, "unable to enable clock");
> + return err;
> + }
prepare_cnt = 1, enable_cnt = 1
> +
> + /* unlock the device */
> + zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);
> +
> + clk_disable(priv->clk);
prepare_cnt = 1, enable_cnt = 0
> +
> + err = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> + &zynq_fpga_ops, priv);
> + if (err) {
> + dev_err(dev, "unable to register FPGA manager");
> + clk_disable_unprepare(priv->clk);
prepare_cnt = 0, enable_cnt = -1 /* OOPS! */
Clock management is still wonky. I think you only want clk_unprepare here.
> + return err;
> + }
> +
Assuming all goes well, you'll be leaving probe() with:
prepare_cnt = 1, enable_cnt = 0.
> + return 0;
> +}
> +
> +static int zynq_fpga_remove(struct platform_device *pdev)
> +{
> + struct zynq_fpga_priv *priv;
> +
> + fpga_mgr_unregister(&pdev->dev);
> +
> + priv = platform_get_drvdata(pdev);
> +
> + clk_disable_unprepare(priv->clk);
Which means, symmetrically, you'll only want this to be a clk_unprepare().
Josh
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