Re: [PATCH v3 4/4] mfd: cros_ec: add RTC as mfd subdevice

[Lee Jones]

On Wed, 12 Jul 2017, Enric Balletbo i Serra wrote:

> From: Stephen Barber <smbarber@xxxxxxxxxxxx>
> 
> If the EC supports RTC host commands, expose an RTC device.
> 
> Signed-off-by: Stephen Barber <smbarber@xxxxxxxxxxxx>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> ---
>  drivers/mfd/cros_ec.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 75a27a6..ff972fb 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -51,6 +51,10 @@ static const struct mfd_cell ec_pd_cell = {
>  	.pdata_size = sizeof(pd_p),
>  };
>  
> +static const struct mfd_cell ec_rtc_cell = {
> +	.name = "cros-ec-rtc",
> +};
> +
>  static irqreturn_t ec_irq_thread(int irq, void *data)
>  {
>  	struct cros_ec_device *ec_dev = data;
> @@ -245,6 +249,16 @@ static void cros_ec_sensors_register(struct cros_ec_device *ec_dev)
>  	kfree(msg);
>  }
>  
> +static void cros_ec_rtc_register(struct cros_ec_device *ec_dev)
> +{
> +	int ret;
> +
> +	ret = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_rtc_cell,
> +			      1, NULL, 0, NULL);
> +	if (ret)
> +		dev_err(ec_dev->dev, "failed to add EC RTC\n");
> +}

Why do you need a new function just to call a single function?

And by making it void, you're also loosing the return value.

If mfd_add_devices() fails, something has gone wrong!

>  int cros_ec_register(struct cros_ec_device *ec_dev)
>  {
>  	struct device *dev = ec_dev->dev;
> @@ -294,6 +308,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
>  	if (cros_ec_check_features(ec_dev, EC_FEATURE_MOTION_SENSE))
>  		cros_ec_sensors_register(ec_dev);
>  
> +	/* Check whether this EC has RTC support */
> +	if (cros_ec_check_features(ec_dev, EC_FEATURE_RTC))
> +		cros_ec_rtc_register(ec_dev);
> +
>  	if (ec_dev->max_passthru) {
>  		/*
>  		 * Register a PD device as well on top of this device.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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