Re: [PATCH 9/9] spi: atmel-quadspi: add support for sam9x60 qspi controller

[Boris Brezillon]

On Wed, 30 Jan 2019 15:08:47 +0000
<tudor.amba...@microchip.com> wrote:

> +static int atmel_sam9x60_qspi_clk_prepare_enable(struct atmel_qspi *aq)
> +{
> +     struct device *dev = &aq->pdev->dev;
> +     int ret;
> +
> +     if (!aq->clk) {
> +             /* Get the peripheral clock */
> +             aq->clk = devm_clk_get(dev, "pclk");
> +             if (IS_ERR(aq->clk)) {
> +                     dev_err(dev, "missing peripheral clock\n");
> +                     return PTR_ERR(aq->clk);
> +             }
> +     }
> +
> +     if (!aq->qspick) {
> +             /* Get the QSPI system clock */
> +             aq->qspick = devm_clk_get(dev, "qspick");
> +             if (IS_ERR(aq->qspick)) {
> +                     dev_err(dev, "missing system clock\n");
> +                     return PTR_ERR(aq->qspick);
> +             }
> +     }

Move the devm_clk_get() calls to the probe path instead of doing it at
prepare time, and you can make it generic for both compats with
something like:

        aq->clk = devm_clk_get(dev, "pclk");
        if (IS_ERR(aq->clk))
                aq->clk = devm_clk_get(dev, NULL);

        if (IS_ERR(aq->clk))
                return PTR_ERR(aq->clk);

        if (aq->caps->qspick_required) {
                aq->qspick = devm_clk_get(dev, "qspick");
                if (IS_ERR(aq->qspick)) {
                        return PTR_ERR(aq->qspick);
        }

> +
> +     /* Enable the peripheral clock */
> +     ret = clk_prepare_enable(aq->clk);
> +     if (ret) {
> +             dev_err(dev, "failed to enable the peripheral clock\n");
> +             return ret;
> +     }
> +
> +     /* Enable the QSPI system clock */
> +     ret = clk_prepare_enable(aq->qspick);
> +     if (ret) {
> +             dev_err(dev, "failed to enable the QSPI system clock\n");
> +             clk_disable_unprepare(aq->clk);
> +     }

Again, you can make the enable function generic since
clk_prepare_enable(NULL) is a NO-OP that returns 0 and aq->qspick will
be NULL when it's not required.

> +
> +     return ret;
> +}
> +
> +static void atmel_sam9x60_qspi_clk_disable_unprepare(struct atmel_qspi *aq)
> +{
> +     clk_disable_unprepare(aq->qspick);
> +     clk_disable_unprepare(aq->clk);

Ditto.

> +}