On Wed, 3 Dec 2014 11:28:55 +0530 Sanchayan Maity <maitysancha...@gmail.com>
wrote:
> This patch adds clock enable and disable support for
> the SNVS peripheral, which is required for using the
> RTC within the SNVS block.
>
> The clock is not strictly enforced, as this would
> break the i.MX devices. The clocking for the i.MX
> devices seems to be enabled elsewhere and enabling
> RTC SNVS for Vybrid results in a crash. This patch
> adds the clock support but also makes it optional
> so Vybrid platform can use the clock if defined
> while making sure not to break i.MX .
>
> ...
I assume this hasn't been tested with CONFIG_HAVE_CLK=n. It all
*looks* OK, but the clk API does its tests for clk==NULL in some very
deep places.
> --- a/drivers/rtc/rtc-snvs.c
> +++ b/drivers/rtc/rtc-snvs.c
.
> ...
>
> @@ -288,10 +302,16 @@ static int snvs_rtc_probe(struct platform_device *pdev)
> if (IS_ERR(data->rtc)) {
> ret = PTR_ERR(data->rtc);
> dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
> - return ret;
> + goto error_rtc_device_register;
> }
>
> return 0;
> +
> +error_rtc_device_register:
> + if (data->clk)
> + clk_disable_unprepare(data->clk);
>From my reading, there's no need to test data->clk here -
clk_disable_unprepare() handles that.
It doesn't hurt to test it - a reasonable approach would be to look
around at what other users of the clk API are doing, and do that.
> + return ret;
> }
>
> #ifdef CONFIG_PM_SLEEP
> @@ -302,16 +322,26 @@ static int snvs_rtc_suspend(struct device *dev)
> if (device_may_wakeup(dev))
> enable_irq_wake(data->irq);
>
> + if (data->clk)
> + clk_disable_unprepare(data->clk);
Ditto.
> return 0;
> }
>
> static int snvs_rtc_resume(struct device *dev)
> {
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> + int ret;
>
> if (device_may_wakeup(dev))
> disable_irq_wake(data->irq);
>
> + if (data->clk) {
> + ret = clk_prepare_enable(data->clk);
> + if (ret)
> + return ret;
> + }
It could be omitted here also.
> return 0;
> }
> #endif
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