// SPDX-License-Identifier: GPL-2.0+
  /*
   * 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>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  #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;
  
  struct imx_sc_msg_timer_get_rtc_time {
  	struct imx_sc_rpc_msg hdr;
  	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 __aligned(4);

  static int imx_sc_rtc_read_time(struct device *dev, struct rtc_time *tm)
  {
  	struct imx_sc_msg_timer_get_rtc_time msg;
  	struct imx_sc_rpc_msg *hdr = &msg.hdr;
  	int ret;
  
  	hdr->ver = IMX_SC_RPC_VERSION;
  	hdr->svc = IMX_SC_RPC_SVC_TIMER;
  	hdr->func = IMX_SC_TIMER_FUNC_GET_RTC_SEC1970;
  	hdr->size = 1;
  
  	ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true);
  	if (ret) {
  		dev_err(dev, "read rtc time failed, ret %d
  ", ret);
  		return ret;
  	}

  	rtc_time64_to_tm(msg.time, tm);

  
  	return 0;
  }

  static int imx_sc_rtc_set_time(struct device *dev, struct rtc_time *tm)
  {
  	struct arm_smccc_res res;
  
  	/* pack 2 time parameters into 1 register, 16 bits for each */
  	arm_smccc_smc(IMX_SIP_SRTC, IMX_SIP_SRTC_SET_TIME,
  		      ((tm->tm_year + 1900) << 16) | (tm->tm_mon + 1),
  		      (tm->tm_mday << 16) | tm->tm_hour,
  		      (tm->tm_min << 16) | tm->tm_sec,
  		      0, 0, 0, &res);
  
  	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
  ", ret);
  		return ret;
  	}
  
  	ret = imx_sc_rtc_alarm_irq_enable(dev, alrm->enabled);
  	if (ret) {
  		dev_err(dev, "enable rtc alarm failed, ret %d
  ", 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)
  {
  	int ret;
  
  	ret = imx_scu_get_handle(&rtc_ipc_handle);
  	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);
  
  	imx_sc_rtc->ops = &imx_sc_rtc_ops;
  	imx_sc_rtc->range_min = 0;
  	imx_sc_rtc->range_max = U32_MAX;
  
  	ret = rtc_register_device(imx_sc_rtc);

  	if (ret)

  		return ret;

  	imx_scu_irq_register_notifier(&imx_sc_rtc_alarm_sc_notifier);

  	return 0;
  }
  
  static const struct of_device_id imx_sc_dt_ids[] = {
  	{ .compatible = "fsl,imx8qxp-sc-rtc", },

  	{ .compatible = "fsl,imx8qm-sc-rtc", },

  	{}
  };
  MODULE_DEVICE_TABLE(of, imx_sc_dt_ids);
  
  static struct platform_driver imx_sc_rtc_driver = {
  	.driver = {
  		.name	= "imx-sc-rtc",
  		.of_match_table = imx_sc_dt_ids,
  	},
  	.probe		= imx_sc_rtc_probe,
  };
  module_platform_driver(imx_sc_rtc_driver);
  
  MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
  MODULE_DESCRIPTION("NXP i.MX System Controller RTC Driver");
  MODULE_LICENSE("GPL");