rtc: imx-sc: add rtc alarm support

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>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-imx-sc.c b/drivers/rtc/rtc-imx-sc.c
index 19642bfd913ae9da6ffc208c761a8ba92b01f516..c933045fe04b73e77a1a263f56b7d4ccfbfda33a 100644 (file)
--- 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;
 }