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From:   Jingbao Qiu <qiujingbao.dlmu@gmail.com>
To:     a.zummo@towertech.it, alexandre.belloni@bootlin.com,
        krzysztof.kozlowski+dt@linaro.org, chao.wei@sophgo.com,
        unicorn_wang@outlook.com, conor+dt@kernel.org, robh+dt@kernel.org,
        conor@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu
Cc:     linux-rtc@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Jingbao Qiu <qiujingbao.dlmu@gmail.com>
Subject: [PATCH 2/3] rtc: add rtc controller support for Sophgo CV1800B SoC
Date:   Tue, 21 Nov 2023 17:46:41 +0800
Message-Id: <20231121094642.2973795-3-qiujingbao.dlmu@gmail.com>
In-Reply-To: <20231121094642.2973795-1-qiujingbao.dlmu@gmail.com>
References: <20231121094642.2973795-1-qiujingbao.dlmu@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Implement the RTC driver for CV1800B, which able to provide time and
alarm functionality.

Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
---
 drivers/rtc/Kconfig       |  10 ++
 drivers/rtc/Makefile      |   1 +
 drivers/rtc/rtc-cv1800b.c | 293 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 304 insertions(+)
 create mode 100644 drivers/rtc/rtc-cv1800b.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 3814e0845e77..2089cceea38c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1103,6 +1103,16 @@ config RTC_DRV_DS2404
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds2404.
 
+config RTC_DRV_CV1800B
+	tristate "Sophgo CV1800B RTC"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	help
+	  If you say yes here you will get support for the
+	  RTC of the Sophgo CV1800B SOC.
+
+	  This depend on ARCH_SOPHGO and COMPILE_TEST. Please
+	  first config that.
+
 config RTC_DRV_DA9052
 	tristate "Dialog DA9052/DA9053 RTC"
 	depends on PMIC_DA9052
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7b03c3abfd78..3717d7ec8a4e 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_RTC_DRV_CADENCE)	+= rtc-cadence.o
 obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc-cmos.o
 obj-$(CONFIG_RTC_DRV_CPCAP)	+= rtc-cpcap.o
 obj-$(CONFIG_RTC_DRV_CROS_EC)	+= rtc-cros-ec.o
+obj-$(CONFIG_RTC_DRV_CV1800B)	+= rtc-cv1800b.o
 obj-$(CONFIG_RTC_DRV_DA9052)	+= rtc-da9052.o
 obj-$(CONFIG_RTC_DRV_DA9055)	+= rtc-da9055.o
 obj-$(CONFIG_RTC_DRV_DA9063)	+= rtc-da9063.o
diff --git a/drivers/rtc/rtc-cv1800b.c b/drivers/rtc/rtc-cv1800b.c
new file mode 100644
index 000000000000..d56132de30bb
--- /dev/null
+++ b/drivers/rtc/rtc-cv1800b.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rtc-cv1800b.c: RTC driver for Sophgo CV1800B RTC
+ *
+ * Author: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+
+#define RTC_ANA_CALIB                 0x000
+#define RTC_SEC_PULSE_GEN             0x004
+#define RTC_ALARM_TIME                0x008
+#define RTC_ALARM_ENABLE              0x00c
+#define RTC_SET_SEC_CNTR_VALUE        0x010
+#define RTC_SET_SEC_CNTR_TRIG         0x014
+#define RTC_SEC_CNTR_VALUE            0x018
+#define RTC_INFO0                     0x01c
+#define RTC_INFO1                     0x020
+#define RTC_INFO2                     0x024
+#define RTC_INFO3                     0x028
+#define RTC_NOPOR_INFO0               0x02c
+#define RTC_NOPOR_INFO1               0x030
+#define RTC_NOPOR_INFO2               0x034
+#define RTC_NOPOR_INFO3               0x038
+#define RTC_DB_PWR_VBAT_DET           0x040
+#define RTC_DB_BUTTON1                0x048
+#define RTC_DB_PWR_ON                 0x04c
+#define RTC_7SEC_RESET                0x050
+#define RTC_THM_SHDN_AUTO_REBOOT      0x064
+#define RTC_POR_DB_MAGIC_KEY          0x068
+#define RTC_DB_SEL_PWR                0x06c
+#define RTC_UP_SEQ0                   0x070
+#define RTC_UP_SEQ1                   0x074
+#define RTC_UP_SEQ2                   0x078
+#define RTC_UP_SEQ3                   0x07c
+#define RTC_UP_IF_EN                  0x080
+#define RTC_UP_RSTN                   0x084
+#define RTC_UP_MAX                    0x088
+#define RTC_DN_SEQ0                   0x090
+#define RTC_DN_SEQ1                   0x094
+#define RTC_DN_SEQ2                   0x098
+#define RTC_DN_SEQ3                   0x09c
+#define RTC_DN_IF_EN                  0x0a0
+#define RTC_DN_RSTN                   0x0a4
+#define RTC_DN_MAX                    0x0a8
+#define RTC_PWR_CYC_MAX               0x0b0
+#define RTC_WARM_RST_MAX              0x0b4
+#define RTC_EN_7SEC_RST               0x0b8
+#define RTC_EN_PWR_WAKEUP             0x0bc
+#define RTC_EN_SHDN_REQ               0x0c0
+#define RTC_EN_THM_SHDN               0x0c4
+#define RTC_EN_PWR_CYC_REQ            0x0c8
+#define RTC_EN_WARM_RST_REQ           0x0cc
+#define RTC_EN_PWR_VBAT_DET           0x0d0
+#define FSM_STATE                     0x0d4
+#define RTC_EN_WDG_RST_REQ            0x0e0
+#define RTC_EN_SUSPEND_REQ            0x0e4
+#define RTC_DB_REQ_WDG_RST            0x0e8
+#define RTC_DB_REQ_SUSPEND            0x0ec
+#define RTC_PG_REG                    0x0f0
+#define RTC_ST_ON_REASON              0x0f8
+#define RTC_ST_OFF_REASON             0x0fc
+#define RTC_EN_WAKEUP_REQ             0x120
+#define RTC_PWR_WAKEUP_POLARITY       0x128
+#define RTC_DB_SEL_REQ                0x130
+#define RTC_PWR_DET_SEL               0x140
+
+#define REG_DISABLE_FUN               0x00UL
+#define REG_ENABLE_FUN                BIT(0)
+#define ACTIVATE_RTC_POR_DB_MAGIC_KEY 0x5af0
+#define INIT_LOAD_TIME                0xff
+
+struct cv1800b_rtc_priv {
+	struct rtc_device *rtc_dev;
+	void __iomem *core_map;
+	struct clk *clk;
+	int irq;
+};
+
+static int cv1800b_rtc_alarm_irq_enable(struct device *dev,
+					unsigned int enabled)
+{
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	if (enabled)
+		writel_relaxed(REG_ENABLE_FUN, data->core_map + RTC_ALARM_ENABLE);
+	else
+		writel_relaxed(REG_DISABLE_FUN,
+			       data->core_map + RTC_ALARM_ENABLE);
+
+	return 0;
+}
+
+static int cv1800b_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+	unsigned long time = rtc_tm_to_time64(&alrm->time);
+
+	writel_relaxed(time, data->core_map + RTC_ALARM_TIME);
+
+	cv1800b_rtc_alarm_irq_enable(dev, 1);
+
+	return 0;
+}
+
+static int cv1800b_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	u32 alrm_time, now_time;
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	alrm_time = readl(data->core_map + RTC_ALARM_TIME);
+	now_time = readl(data->core_map + RTC_SEC_CNTR_VALUE);
+	rtc_time64_to_tm(alrm_time, &alrm->time);
+	alrm->pending = now_time > alrm_time ? 1 : 0;
+	alrm->enabled = readl(data->core_map + RTC_ALARM_ENABLE);
+
+	return 0;
+}
+
+static int cv1800b_rtc_softinit(struct cv1800b_rtc_priv *dev)
+{
+	u32 timeout = 20;
+
+	writel(ACTIVATE_RTC_POR_DB_MAGIC_KEY,
+	       dev->core_map + RTC_POR_DB_MAGIC_KEY);
+	writel(INIT_LOAD_TIME, dev->core_map + RTC_SET_SEC_CNTR_VALUE);
+	writel(REG_DISABLE_FUN, dev->core_map + RTC_SET_SEC_CNTR_TRIG);
+
+	while (readl(dev->core_map + RTC_SEC_CNTR_VALUE) == INIT_LOAD_TIME
+	       && timeout--)
+		udelay(5);
+
+	if (!timeout)
+		return -1;
+	return 0;
+}
+
+static int cv1800b_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+	u32 time = 0;
+
+	if (!data)
+		return -1;
+
+	time = readl_relaxed(data->core_map + RTC_SEC_CNTR_VALUE);
+	rtc_time64_to_tm(time, tm);
+
+	return 0;
+}
+
+static int cv1800b_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned long time = rtc_tm_to_time64(tm);
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	if (!data)
+		return -1;
+
+	writel(time, data->core_map + RTC_SET_SEC_CNTR_VALUE);
+	writel(REG_ENABLE_FUN, data->core_map + RTC_SET_SEC_CNTR_TRIG);
+
+	return 0;
+}
+
+static irqreturn_t cv1800b_rtc_irq_handler(int irq, void *dev_id)
+{
+	struct device *dev = dev_id;
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	if (!data)
+		return -1;
+	writel(REG_DISABLE_FUN, data->core_map + RTC_ALARM_ENABLE);
+
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops cv800b_rtc_ops = {
+	.read_time = cv1800b_rtc_read_time,
+	.set_time = cv1800b_rtc_set_time,
+	.read_alarm = cv1800b_rtc_read_alarm,
+	.set_alarm = cv1800b_rtc_set_alarm,
+	.alarm_irq_enable = cv1800b_rtc_alarm_irq_enable,
+};
+
+static int cv1800b_rtc_probe(struct platform_device *pdev)
+{
+	struct cv1800b_rtc_priv *rtc;
+	struct resource *res;
+	int ret;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	rtc->core_map = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(rtc->core_map)) {
+		ret = PTR_ERR(rtc->core_map);
+		goto err;
+	}
+
+	rtc->irq = platform_get_irq(pdev, 0);
+	platform_set_drvdata(pdev, rtc);
+	if (rtc->irq < 0) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	ret =
+	    devm_request_irq(&pdev->dev, rtc->irq, cv1800b_rtc_irq_handler,
+			     IRQF_SHARED, "rtc alarm", &pdev->dev);
+	if (ret)
+		goto err;
+
+	rtc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(rtc->clk)) {
+		dev_err(&pdev->dev, "no clock");
+		ret = PTR_ERR(rtc->clk);
+		goto err;
+	}
+	ret = clk_prepare_enable(rtc->clk);
+	if (ret)
+		goto err;
+	ret = cv1800b_rtc_softinit(rtc);
+	if (ret)
+		goto err;
+	cv1800b_rtc_alarm_irq_enable(&pdev->dev, 1);
+	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtc_dev)) {
+		ret = PTR_ERR(rtc->rtc_dev);
+		goto err;
+	}
+	rtc->rtc_dev->range_max = U32_MAX;
+	rtc->rtc_dev->ops = &cv800b_rtc_ops;
+
+	return rtc_register_device(rtc->rtc_dev);
+err:
+	return dev_err_probe(&pdev->dev, ret, "Failed to init cv1800b rtc\n");
+}
+
+static int __maybe_unused cv1800b_rtc_suspend_noirq(struct device *dev)
+{
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static int __maybe_unused cv1800b_rtc_resume_noirq(struct device *dev)
+{
+	struct cv1800b_rtc_priv *data = dev_get_drvdata(dev);
+
+	clk_prepare_enable(data->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cv1800b_rtc_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(cv1800b_rtc_suspend_noirq,
+				      cv1800b_rtc_resume_noirq)
+};
+
+static const struct of_device_id cv1800b_dt_ids[] = {
+	{ .compatible = "sophgo,cv800b-rtc" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, cv1800b_dt_ids);
+
+static struct platform_driver cv1800b_rtc_driver = {
+	.driver = {
+		   .name = "sophgo-cv800b-rtc",
+		   .pm = &cv1800b_rtc_pm_ops,
+		   .of_match_table = cv1800b_dt_ids,
+		    },
+	.probe = cv1800b_rtc_probe,
+};
+
+module_platform_driver(cv1800b_rtc_driver);
+MODULE_AUTHOR("Jingbao Qiu");
+MODULE_DESCRIPTION("Sophgo CV1800B RTC Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1