Hello, On 21/06/2024 15:04:41+0800, Peng Fan (OSS) wrote: > + ret = bbnsm->ops->rtc_time_get(ph, 0, &val); > + if (ret) { > + dev_err(dev, "%s: %d\n", __func__, ret); This is not super useful, you should drop the various dev_err or pr_err as there is no action the user can take to solve the erro apart from retrying. > + return ret; > + } > + > + rtc_time64_to_tm(val, tm); > + > + return 0; > +} > + > +static int scmi_imx_bbm_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct scmi_imx_bbm *bbnsm = dev_get_drvdata(dev); > + struct scmi_protocol_handle *ph = bbnsm->ph; > + u64 val; > + int ret; > + > + val = rtc_tm_to_time64(tm); > + > + ret = bbnsm->ops->rtc_time_set(ph, 0, val); > + if (ret) > + dev_err(dev, "%s: %d\n", __func__, ret); > + > + return ret; > +} > + > +static int scmi_imx_bbm_alarm_irq_enable(struct device *dev, unsigned int enable) > +{ How can userspace disable the alarm? > + return 0; > +} > + > +static int scmi_imx_bbm_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) > +{ > + struct scmi_imx_bbm *bbnsm = dev_get_drvdata(dev); > + struct scmi_protocol_handle *ph = bbnsm->ph; > + struct rtc_time *alrm_tm = &alrm->time; > + u64 val; > + int ret; > + > + val = rtc_tm_to_time64(alrm_tm); > + > + ret = bbnsm->ops->rtc_alarm_set(ph, 0, val); > + if (ret) > + dev_err(dev, "%s: %d\n", __func__, ret); > + > + return ret; > +} > + > +static const struct rtc_class_ops smci_imx_bbm_rtc_ops = { > + .read_time = scmi_imx_bbm_read_time, > + .set_time = scmi_imx_bbm_set_time, > + .set_alarm = scmi_imx_bbm_set_alarm, > + .alarm_irq_enable = scmi_imx_bbm_alarm_irq_enable, > +}; > + > +static int scmi_imx_bbm_rtc_notifier(struct notifier_block *nb, unsigned long event, void *data) > +{ > + struct scmi_imx_bbm *bbnsm = container_of(nb, struct scmi_imx_bbm, nb); > + struct scmi_imx_bbm_notif_report *r = data; > + > + if (r->is_rtc) > + rtc_update_irq(bbnsm->rtc_dev, 1, RTC_AF | RTC_IRQF); > + else > + pr_err("Unexpected bbm event: %s\n", __func__); > + > + return 0; > +} > + > +static int scmi_imx_bbm_rtc_init(struct scmi_device *sdev) > +{ > + const struct scmi_handle *handle = sdev->handle; > + struct device *dev = &sdev->dev; > + struct scmi_imx_bbm *bbnsm = dev_get_drvdata(dev); > + int ret; > + > + bbnsm->rtc_dev = devm_rtc_allocate_device(dev); > + if (IS_ERR(bbnsm->rtc_dev)) > + return PTR_ERR(bbnsm->rtc_dev); > + > + bbnsm->rtc_dev->ops = &smci_imx_bbm_rtc_ops; > + bbnsm->rtc_dev->range_min = 0; range_min is set to 0 by default, this is not necessary > + bbnsm->rtc_dev->range_max = U32_MAX; > + > + ret = devm_rtc_register_device(bbnsm->rtc_dev); > + if (ret) > + return ret; > + > + bbnsm->nb.notifier_call = &scmi_imx_bbm_rtc_notifier; > + return handle->notify_ops->devm_event_notifier_register(sdev, SCMI_PROTOCOL_IMX_BBM, > + SCMI_EVENT_IMX_BBM_RTC, > + NULL, &bbnsm->nb); Note that failing after devm_rtc_register_device opens the driver to a race condition as the character device will exist at that time. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com