Re: [Patch v3 3/7] rtc: DA9055 RTC driver

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 13 Dec 2012 18:34:20 +0530
Ashish Jangam <ashish.jangam@kpitcummins.com> wrote:

> (This rtc patch is resend for merge)
> ---
> This is the RTC patch for the DA9055 PMIC. This patch has got dependency on
> the DA9055 MFD core.
> 
> This patch is functionally tested on Samsung SMDKV6410.
> 
> ...
>
> +static int __init da9055_rtc_device_init(struct da9055 *da9055,
> +					struct da9055_pdata *pdata)
> +{
> +	int ret;
> +
> +	/* Enable RTC and the internal Crystal */
> +	ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
> +				DA9055_RTC_EN, DA9055_RTC_EN);
> +	if (ret < 0)
> +		return ret;
> +	ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
> +				DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Enable RTC in Power Down mode */
> +	ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
> +				DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Enable RTC in Reset mode */
> +	if (pdata && pdata->reset_enable) {
> +		ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
> +					DA9055_RTC_MODE_SD,
> +					DA9055_RTC_MODE_SD <<
> +					DA9055_RTC_MODE_SD_SHIFT);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	/* Disable the RTC TICK ALM */
> +	ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
> +				DA9055_RTC_TICK_WAKE_MASK, 0);
> +	if (ret < 0)
> +		return ret;

If one of these failure paths is taken, the hardware will be left in a
part-initialised state.  Is this wise?

> +	return 0;
> +}