Re: [PATCH V3 3/3] rtc: omap: Support regulator supply for RTC

[Johan Hovold <johan@kernel.org>]

On Fri, Oct 24, 2014 at 10:23:45AM +0530, Lokesh Vutla wrote:
> On some Soc's RTC is powered by an external power regulator.
> e.g. RTC on DRA7 SoC. Make the OMAP RTC driver support a
> power regulator.
> 
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> ---
>  Documentation/devicetree/bindings/rtc/rtc-omap.txt |  3 +++
>  drivers/rtc/rtc-omap.c                             | 24 ++++++++++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-omap.txt b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> index 750efd4..e7ad12b 100644
> --- a/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> +++ b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> @@ -15,6 +15,8 @@ Required properties:
>  Optional properties:
>  - ti,system-power-controller: whether the rtc is controlling the system power
>    through pmic_power_en
> +Optional Properties:

No need to repeat the "Optional Properties" header.

> +- vrtc-supply: phandle to the regulator device tree node if needed
>  
>  Example:
>  
> @@ -25,4 +27,5 @@ rtc@1c23000 {
>  		      19>;
>  	interrupt-parent = <&intc>;
>  	ti,system-power-controller;
> +	vrtc-supply = <&ldo9_reg>;
>  };
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index d9bb5e7..61fe630 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -25,6 +25,7 @@
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/io.h>
> +#include <linux/regulator/consumer.h>
>  
>  /*
>   * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
> @@ -134,6 +135,7 @@ struct omap_rtc {
>  	u8 interrupts_reg;
>  	bool is_pmic_controller;
>  	const struct omap_rtc_device_type *type;
> +	struct regulator *supply;
>  };
>  
>  static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
> @@ -516,6 +518,22 @@ static int omap_rtc_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, rtc);

Also could you move the regulator allocation before this
platform_set_drvdata when resending? It's not required, but that call
sort of separates the allocations from the device initialisation
currently.

> +	rtc->supply = devm_regulator_get_optional(&pdev->dev, "vrtc");
> +	if (IS_ERR(rtc->supply)) {
> +		if (PTR_ERR(rtc->supply) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +
> +		rtc->supply = NULL;
> +	}
> +
> +	if (rtc->supply) {
> +		ret = regulator_enable(rtc->supply);
> +		if (ret) {
> +			dev_err(&pdev->dev, "regulator enable failed\n");
> +			return ret;
> +		}
> +	}
> +
>  	/* Enable the clock/module so that we can access the registers */
>  	pm_runtime_enable(&pdev->dev);
>  	pm_runtime_get_sync(&pdev->dev);
> @@ -624,6 +642,9 @@ err:
>  	pm_runtime_put_sync(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  
> +	if (rtc->supply)
> +		regulator_disable(rtc->supply);
> +
>  	return ret;
>  }
>  
> @@ -649,6 +670,9 @@ static int __exit omap_rtc_remove(struct platform_device *pdev)
>  	pm_runtime_put_sync(&pdev->dev);
>  	pm_runtime_disable(&pdev->dev);
>  
> +	if (rtc->supply)
> +		regulator_disable(rtc->supply);
> +
>  	return 0;
>  }

Looks good otherwise. Feel free to add

Reviewed-by: Johan Hovold <johan@kernel.org>

Thanks,
Johan