Re: [PATCH V7 4/4] rtc: imx-sc: add rtc alarm support

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 09/04/2019 05:00:07+0000, Anson Huang wrote:
> Add i.MX system controller RTC alarm support, the RTC alarm
> is implemented via SIP(silicon provider) runtime service call
> and ARM-Trusted-Firmware will communicate with system controller
> via MU(message unit) IPC to set RTC alarm. When RTC alarm fires,
> system controller will generate a common MU irq event and notify
> system controller RTC driver to handle the irq event.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
> Changes since V6:
> 	- add comments to .read_alarm callback function to explain why it is an empty function;
> 	- improve irq notify callback function name.
> --
>  drivers/rtc/rtc-imx-sc.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-imx-sc.c b/drivers/rtc/rtc-imx-sc.c
> index 19642bf..c933045 100644
> --- a/drivers/rtc/rtc-imx-sc.c
> +++ b/drivers/rtc/rtc-imx-sc.c
> @@ -3,6 +3,7 @@
>   * Copyright 2018 NXP.
>   */
>  
> +#include <dt-bindings/firmware/imx/rsrc.h>
>  #include <linux/arm-smccc.h>
>  #include <linux/firmware/imx/sci.h>
>  #include <linux/module.h>
> @@ -11,11 +12,15 @@
>  #include <linux/rtc.h>
>  
>  #define IMX_SC_TIMER_FUNC_GET_RTC_SEC1970	9
> +#define IMX_SC_TIMER_FUNC_SET_RTC_ALARM		8
>  #define IMX_SC_TIMER_FUNC_SET_RTC_TIME		6
>  
>  #define IMX_SIP_SRTC			0xC2000002
>  #define IMX_SIP_SRTC_SET_TIME		0x0
>  
> +#define SC_IRQ_GROUP_RTC    2
> +#define SC_IRQ_RTC          1
> +
>  static struct imx_sc_ipc *rtc_ipc_handle;
>  static struct rtc_device *imx_sc_rtc;
>  
> @@ -24,6 +29,16 @@ struct imx_sc_msg_timer_get_rtc_time {
>  	u32 time;
>  } __packed;
>  
> +struct imx_sc_msg_timer_rtc_set_alarm {
> +	struct imx_sc_rpc_msg hdr;
> +	u16 year;
> +	u8 mon;
> +	u8 day;
> +	u8 hour;
> +	u8 min;
> +	u8 sec;
> +} __packed;
> +
>  static int imx_sc_rtc_read_time(struct device *dev, struct rtc_time *tm)
>  {
>  	struct imx_sc_msg_timer_get_rtc_time msg;
> @@ -60,9 +75,77 @@ static int imx_sc_rtc_set_time(struct device *dev, struct rtc_time *tm)
>  	return res.a0;
>  }
>  
> +static int imx_sc_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
> +{
> +	return imx_scu_irq_group_enable(SC_IRQ_GROUP_RTC, SC_IRQ_RTC, enable);
> +}
> +
> +static int imx_sc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	/*
> +	 * SCU firmware does NOT provide read alarm API, but .read_alarm
> +	 * callback is required by RTC framework to support alarm function,
> +	 * so just return here.
> +	 */
> +	return 0;
> +}
> +
> +static int imx_sc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct imx_sc_msg_timer_rtc_set_alarm msg;
> +	struct imx_sc_rpc_msg *hdr = &msg.hdr;
> +	int ret;
> +	struct rtc_time *alrm_tm = &alrm->time;
> +
> +	hdr->ver = IMX_SC_RPC_VERSION;
> +	hdr->svc = IMX_SC_RPC_SVC_TIMER;
> +	hdr->func = IMX_SC_TIMER_FUNC_SET_RTC_ALARM;
> +	hdr->size = 3;
> +
> +	msg.year = alrm_tm->tm_year + 1900;
> +	msg.mon = alrm_tm->tm_mon + 1;
> +	msg.day = alrm_tm->tm_mday;
> +	msg.hour = alrm_tm->tm_hour;
> +	msg.min = alrm_tm->tm_min;
> +	msg.sec = alrm_tm->tm_sec;
> +
> +	ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true);
> +	if (ret) {
> +		dev_err(dev, "set rtc alarm failed, ret %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = imx_sc_rtc_alarm_irq_enable(dev, alrm->enabled);
> +	if (ret) {
> +		dev_err(dev, "enable rtc alarm failed, ret %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  static const struct rtc_class_ops imx_sc_rtc_ops = {
>  	.read_time = imx_sc_rtc_read_time,
>  	.set_time = imx_sc_rtc_set_time,
> +	.read_alarm = imx_sc_rtc_read_alarm,
> +	.set_alarm = imx_sc_rtc_set_alarm,
> +	.alarm_irq_enable = imx_sc_rtc_alarm_irq_enable,
> +};
> +
> +static int imx_sc_rtc_alarm_notify(struct notifier_block *nb,
> +					unsigned long event, void *group)
> +{
> +	/* ignore non-rtc irq */
> +	if (!((event & SC_IRQ_RTC) && (*(u8 *)group == SC_IRQ_GROUP_RTC)))
> +		return 0;
> +
> +	rtc_update_irq(imx_sc_rtc, 1, RTC_IRQF | RTC_AF);
> +
> +	return 0;
> +}
> +
> +static struct notifier_block imx_sc_rtc_alarm_sc_notifier = {
> +	.notifier_call = imx_sc_rtc_alarm_notify,
>  };
>  
>  static int imx_sc_rtc_probe(struct platform_device *pdev)
> @@ -73,6 +156,8 @@ static int imx_sc_rtc_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	device_init_wakeup(&pdev->dev, true);
> +
>  	imx_sc_rtc = devm_rtc_allocate_device(&pdev->dev);
>  	if (IS_ERR(imx_sc_rtc))
>  		return PTR_ERR(imx_sc_rtc);
> @@ -87,6 +172,8 @@ static int imx_sc_rtc_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	imx_scu_irq_register_notifier(&imx_sc_rtc_alarm_sc_notifier);
> +
>  	return 0;
>  }
>  
> -- 
> 2.7.4
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com