On 10/23/2014 11:53 PM, Lokesh Vutla wrote:
> On some Soc's RTC is powered by an external power regulator.
SoC ? -> could you rephrase this to indicate "certain SoCs such as
DRA7, RTC is an independent voltage domain of it's own and on
platforms such as DRA7-evm, this may be supplied by individual
regulator on it's own.
> e.g. RTC on DRA7 SoC. Make the OMAP RTC driver support a
> power regulator.
Question ofcourse is what voltage would you like that regulator to be
at? As you are aware, certain LDOs and SMPS can drive varying voltage
and just enable/disable would do just the default voltage of the
SMPS/LDO, right? OR am i missing something here?
>
> Signed-off-by: Lokesh Vutla <lokeshvutla@xxxxxx>
> ---
> 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:
^^ already commented on..
> +- vrtc-supply: phandle to the regulator device tree node if needed
"phandle to supply regulator" ? since it is optional, "if needed" is
redundant?
>
> 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);
>
> + 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");
would be nice to print the result as well - since it helps debug from
log a little easier.
--
Regards,
Nishanth Menon
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