diff mbox series

[v2,2/3] rtc: support for the Amlogic on-chip RTC

Message ID 20240903-rtc-v2-2-05da5755b8d9@amlogic.com (mailing list archive)
State Superseded
Headers show
Series support for amlogic rtc | expand

Commit Message

Xianwei Zhao via B4 Relay Sept. 3, 2024, 7 a.m. UTC
From: Yiting Deng <yiting.deng@amlogic.com>

Support for the on-chip RTC found in some of Amlogic's SoCs such as the
A4(A113L2) and A5(A113X2). The RTC hardware includes a timing function
and an alarm function.

Signed-off-by: Yiting Deng <yiting.deng@amlogic.com>
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
 drivers/rtc/Kconfig          |  12 ++
 drivers/rtc/Makefile         |   1 +
 drivers/rtc/rtc-amlogic-a4.c | 481 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 494 insertions(+)

Comments

Krzysztof Kozlowski Sept. 3, 2024, 2:04 p.m. UTC | #1
On 03/09/2024 09:00, Xianwei Zhao via B4 Relay wrote:
> From: Yiting Deng <yiting.deng@amlogic.com>
> 

...

> +	rtc->map = devm_regmap_init_mmio(&pdev->dev, base, &aml_rtc_regmap_config);
> +	if (IS_ERR(rtc->map)) {
> +		dev_err_probe(&pdev->dev, PTR_ERR(rtc->map), "regmap init failed\n");
> +		return PTR_ERR(rtc->map);

Nothing improved. Read the comment. Use git grep to see how this is done
if the comment is somehow unclear.

<form letter>
This is a friendly reminder during the review process.

It seems my or other reviewer's previous comments were not fully
addressed. Maybe the feedback got lost between the quotes, maybe you
just forgot to apply it. Please go back to the previous discussion and
either implement all requested changes or keep discussing them.

Thank you.
</form letter>

Best regards,
Krzysztof
Xianwei Zhao Sept. 4, 2024, 8:44 a.m. UTC | #2
Hi Krzysztof,
    Thanks for your reply.

On 2024/9/3 22:04, Krzysztof Kozlowski wrote:
> [ EXTERNAL EMAIL ]
> 
> On 03/09/2024 09:00, Xianwei Zhao via B4 Relay wrote:
>> From: Yiting Deng <yiting.deng@amlogic.com>
>>
> 
> ...
> 
>> +     rtc->map = devm_regmap_init_mmio(&pdev->dev, base, &aml_rtc_regmap_config);
>> +     if (IS_ERR(rtc->map)) {
>> +             dev_err_probe(&pdev->dev, PTR_ERR(rtc->map), "regmap init failed\n");
>> +             return PTR_ERR(rtc->map);
> 
> Nothing improved. Read the comment. Use git grep to see how this is done
> if the comment is somehow unclear.
> 

Got it, Merge two statements into one.
"return dev_err_probe();"
Will fix it.

> <form letter>
> This is a friendly reminder during the review process.
> 
> It seems my or other reviewer's previous comments were not fully
> addressed. Maybe the feedback got lost between the quotes, maybe you
> just forgot to apply it. Please go back to the previous discussion and
> either implement all requested changes or keep discussing them.
> 

"So the third driver? What is wrong with existing ones? And why this one
  is named so differently?"
Are you saying these part were not fully addressed? If so, let me answer 
it here.

Yes, this is the third driver.The RTC hardware of A4 SoC is different 
from the previous one,  so need add new RTC driver to support it.

A4 RTC hardware includes a timing function and an alarm function.
But the existing has only timing function, alarm function is using the 
system clock to implement a virtual alarm.

The driver file name modfiy to rtc-amlogic-a4.c suggested by Alexandre 
Belloni.

> Thank you.
> </form letter>
> 
> Best regards,
> Krzysztof
>
diff mbox series

Patch

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2a95b05982ad..1d49738a2796 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -2043,4 +2043,16 @@  config RTC_DRV_SSD202D
 	  This driver can also be built as a module, if so, the module
 	  will be called "rtc-ssd20xd".
 
+config RTC_DRV_AMLOGIC_A4
+	tristate "Amlogic RTC"
+	depends on ARCH_MESON || COMPILE_TEST
+	select REGMAP_MMIO
+	default y
+	help
+	  If you say yes here you get support for the RTC block on the
+	  Amlogic A113L2(A4) and A113X2(A5) SoCs.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called "rtc-amlogic-a4".
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 3004e372f25f..2122f469e633 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -26,6 +26,7 @@  obj-$(CONFIG_RTC_DRV_ABB5ZES3)	+= rtc-ab-b5ze-s3.o
 obj-$(CONFIG_RTC_DRV_ABEOZ9)	+= rtc-ab-eoz9.o
 obj-$(CONFIG_RTC_DRV_ABX80X)	+= rtc-abx80x.o
 obj-$(CONFIG_RTC_DRV_AC100)	+= rtc-ac100.o
+obj-$(CONFIG_RTC_DRV_AMLOGIC_A4)	+= rtc-amlogic-a4.o
 obj-$(CONFIG_RTC_DRV_ARMADA38X)	+= rtc-armada38x.o
 obj-$(CONFIG_RTC_DRV_AS3722)	+= rtc-as3722.o
 obj-$(CONFIG_RTC_DRV_ASM9260)	+= rtc-asm9260.o
diff --git a/drivers/rtc/rtc-amlogic-a4.c b/drivers/rtc/rtc-amlogic-a4.c
new file mode 100644
index 000000000000..93f1a7faab84
--- /dev/null
+++ b/drivers/rtc/rtc-amlogic-a4.c
@@ -0,0 +1,481 @@ 
+// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
+/*
+ * Copyright (C) 2024 Amlogic, Inc. All rights reserved
+ * Author: Yiting Deng <yiting.deng@amlogic.com>
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/bitfield.h>
+#include <linux/rtc.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/time64.h>
+#include <linux/delay.h>
+
+/* rtc oscillator rate */
+#define OSC_32K			(32768)
+#define OSC_24M			(24000000)
+
+#define RTC_CTRL		(0x0 << 2)		/* Control RTC */
+#define RTC_ALRM0_EN		BIT(0)
+#define RTC_OSC_SEL		BIT(8)
+#define RTC_ENABLE		BIT(12)
+
+#define RTC_COUNTER_REG		(0x1 << 2)		/* Program RTC counter initial value */
+
+#define RTC_ALARM0_REG		(0x2 << 2)		/* Program RTC alarm0 value */
+
+#define RTC_SEC_ADJUST_REG	(0x6 << 2)		/* Control second-based timing adjustment */
+#define RTC_MATCH_COUNTER	GENMASK(18, 0)
+#define RTC_SEC_ADJUST_CTRL	GENMASK(20, 19)
+#define RTC_ADJ_VALID		BIT(23)
+
+#define RTC_INT_MASK		(0x8 << 2)		/* RTC interrupt mask */
+#define RTC_ALRM0_IRQ_MSK	BIT(0)
+
+#define RTC_INT_CLR		(0x9 << 2)		/* Clear RTC interrupt */
+#define RTC_ALRM0_IRQ_CLR	BIT(0)
+
+#define RTC_OSCIN_CTRL0		(0xa << 2)		/* Control RTC clk from 24M */
+#define RTC_OSCIN_CTRL1		(0xb << 2)		/* Control RTC clk from 24M */
+#define RTC_OSCIN_IN_EN		BIT(31)
+#define RTC_OSCIN_OUT_CFG	GENMASK(29, 28)
+#define RTC_OSCIN_OUT_N0M0	GENMASK(11, 0)
+#define RTC_OSCIN_OUT_N1M1	GENMASK(23, 12)
+
+#define RTC_INT_STATUS		(0xc << 2)		/* RTC interrupt status */
+#define RTC_ALRM0_IRQ_STATUS	BIT(0)
+
+#define RTC_REAL_TIME		(0xd << 2)		/* RTC time value */
+
+#define RTC_OSCIN_OUT_32K_N0	0x2dc
+#define RTC_OSCIN_OUT_32K_N1	0x2db
+#define RTC_OSCIN_OUT_32K_M0	0x1
+#define RTC_OSCIN_OUT_32K_M1	0x2
+
+#define RTC_SWALLOW_SECOND	0x2
+#define RTC_INSERT_SECOND	0x3
+
+struct aml_rtc_config {
+	bool gray_stored;
+};
+
+struct aml_rtc_data {
+	struct regmap *map;
+	struct rtc_device *rtc_dev;
+	int irq;
+	struct clk *rtc_clk;
+	struct clk *sys_clk;
+	int rtc_enabled;
+	const struct aml_rtc_config *config;
+};
+
+static const struct regmap_config aml_rtc_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = RTC_REAL_TIME,
+};
+
+static inline u32 gray_to_binary(u32 gray)
+{
+	u32 bcd = gray;
+	int size = sizeof(bcd) * 8;
+	int i;
+
+	for (i = 0; (1 << i) < size; i++)
+		bcd ^= bcd >> (1 << i);
+
+	return bcd;
+}
+
+static inline u32 binary_to_gray(u32 bcd)
+{
+	return bcd ^ (bcd >> 1);
+}
+
+static int aml_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	u32 time_sec;
+
+	/* if RTC disabled, read time failed */
+	if (!rtc->rtc_enabled) {
+		dev_err(dev, "RTC disabled, read time failed\n");
+		return -EINVAL;
+	}
+
+	regmap_read(rtc->map, RTC_REAL_TIME, &time_sec);
+	if (rtc->config->gray_stored)
+		time_sec = gray_to_binary(time_sec);
+	rtc_time64_to_tm(time_sec, tm);
+	dev_dbg(dev, "%s: read time = %us\n", __func__, time_sec);
+
+	return 0;
+}
+
+static int aml_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	u32 time_sec;
+
+	/* if RTC disabled, first enable it */
+	if (!rtc->rtc_enabled) {
+		regmap_write_bits(rtc->map, RTC_CTRL, RTC_ENABLE, RTC_ENABLE);
+		usleep_range(100, 200);
+		rtc->rtc_enabled = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ENABLE);
+	}
+
+	time_sec = rtc_tm_to_time64(tm);
+	if (rtc->config->gray_stored)
+		time_sec = binary_to_gray(time_sec);
+	regmap_write(rtc->map, RTC_COUNTER_REG, time_sec);
+	dev_dbg(dev, "%s: set time = %us\n", __func__, time_sec);
+
+	return 0;
+}
+
+static int aml_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	time64_t alarm_sec = 0;
+
+	/* if RTC disabled, set alarm failed */
+	if (!rtc->rtc_enabled) {
+		dev_err(dev, "RTC disabled, set alarm failed\n");
+		return -EINVAL;
+	}
+
+	regmap_update_bits(rtc->map, RTC_CTRL,
+			   RTC_ALRM0_EN, RTC_ALRM0_EN);
+	regmap_update_bits(rtc->map, RTC_INT_MASK,
+			   RTC_ALRM0_IRQ_MSK, 0);
+
+	alarm_sec = rtc_tm_to_time64(&alarm->time);
+	if (rtc->config->gray_stored)
+		alarm_sec = binary_to_gray(alarm_sec);
+	regmap_write(rtc->map, RTC_ALARM0_REG, alarm_sec);
+
+	dev_dbg(dev, "%s: alarm->enabled=%d alarm_set=%llds\n", __func__,
+		alarm->enabled, alarm_sec);
+
+	return 0;
+}
+
+static int aml_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	u32 alarm_sec;
+	int alarm_enable, alarm_mask;
+
+	/* if RTC disabled, read alarm failed */
+	if (!rtc->rtc_enabled) {
+		dev_err(dev, "RTC disabled, read alarm failed\n");
+		return -EINVAL;
+	}
+
+	regmap_read(rtc->map, RTC_ALARM0_REG, &alarm_sec);
+	if (rtc->config->gray_stored)
+		alarm_sec = gray_to_binary(alarm_sec);
+	rtc_time64_to_tm(alarm_sec, &alarm->time);
+
+	alarm_enable = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ALRM0_EN);
+	alarm_mask = regmap_test_bits(rtc->map, RTC_INT_MASK, RTC_ALRM0_IRQ_MSK);
+	alarm->enabled = (alarm_enable && !alarm_mask) ? 1 : 0;
+	dev_dbg(dev, "%s: alarm->enabled=%d alarm=%us\n", __func__,
+		alarm->enabled, alarm_sec);
+
+	return 0;
+}
+
+static int aml_rtc_read_offset(struct device *dev, long *offset)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	u32 reg_val;
+	long val;
+	int sign, match_counter, enable;
+
+	/* if RTC disabled, read offset failed */
+	if (!rtc->rtc_enabled) {
+		dev_err(dev, "RTC disabled, read offset failed\n");
+		return -EINVAL;
+	}
+
+	regmap_read(rtc->map, RTC_SEC_ADJUST_REG, &reg_val);
+	enable = FIELD_GET(RTC_ADJ_VALID, reg_val);
+	if (!enable) {
+		val = 0;
+	} else {
+		sign = FIELD_GET(RTC_SEC_ADJUST_CTRL, reg_val);
+		match_counter = FIELD_GET(RTC_MATCH_COUNTER, reg_val);
+		val = 1000000000 / (match_counter + 1);
+		if (sign == RTC_SWALLOW_SECOND)
+			val = -val;
+	}
+	*offset = val;
+
+	return 0;
+}
+
+static int aml_rtc_set_offset(struct device *dev, long offset)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+	int sign = 0, match_counter = 0, enable = 0;
+	u32 reg_val;
+
+	/* if RTC disabled, set offset failed */
+	if (!rtc->rtc_enabled) {
+		dev_err(dev, "RTC disabled, set offset failed\n");
+		return -EINVAL;
+	}
+
+	if (offset) {
+		enable = 1;
+		sign = offset < 0 ? RTC_SWALLOW_SECOND : RTC_INSERT_SECOND;
+		match_counter = 1000000000 / abs(offset) - 1;
+		if (match_counter < 0 || match_counter > RTC_MATCH_COUNTER)
+			return -EINVAL;
+	}
+
+	reg_val = FIELD_PREP(RTC_ADJ_VALID, enable) |
+		  FIELD_PREP(RTC_SEC_ADJUST_CTRL, sign) |
+		  FIELD_PREP(RTC_MATCH_COUNTER, match_counter);
+	regmap_write(rtc->map, RTC_SEC_ADJUST_REG, reg_val);
+
+	return 0;
+}
+
+static int aml_rtc_alarm_enable(struct device *dev, unsigned int enabled)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+	if (enabled) {
+		regmap_update_bits(rtc->map, RTC_CTRL,
+				   RTC_ALRM0_EN, RTC_ALRM0_EN);
+		regmap_update_bits(rtc->map, RTC_INT_MASK,
+				   RTC_ALRM0_IRQ_MSK, 0);
+	} else {
+		regmap_update_bits(rtc->map, RTC_INT_MASK,
+				   RTC_ALRM0_IRQ_MSK, RTC_ALRM0_IRQ_MSK);
+		regmap_update_bits(rtc->map, RTC_CTRL,
+				   RTC_ALRM0_EN, 0);
+	}
+
+	return 0;
+}
+
+static const struct rtc_class_ops aml_rtc_ops = {
+	.read_time = aml_rtc_read_time,
+	.set_time = aml_rtc_set_time,
+	.read_alarm = aml_rtc_read_alarm,
+	.set_alarm = aml_rtc_set_alarm,
+	.alarm_irq_enable = aml_rtc_alarm_enable,
+	.read_offset = aml_rtc_read_offset,
+	.set_offset = aml_rtc_set_offset,
+};
+
+static irqreturn_t aml_rtc_handler(int irq, void *data)
+{
+	struct aml_rtc_data *rtc = (struct aml_rtc_data *)data;
+
+	regmap_write(rtc->map, RTC_ALARM0_REG, 0);
+	regmap_write(rtc->map, RTC_INT_CLR, RTC_ALRM0_IRQ_STATUS);
+
+	rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
+
+	return IRQ_HANDLED;
+}
+
+static void aml_rtc_init(struct aml_rtc_data *rtc)
+{
+	u32 reg_val = 0;
+
+	rtc->rtc_enabled = regmap_test_bits(rtc->map, RTC_CTRL, RTC_ENABLE);
+	if (!rtc->rtc_enabled) {
+		if (clk_get_rate(rtc->rtc_clk) == OSC_24M) {
+			/* select 24M oscillator */
+			regmap_write_bits(rtc->map, RTC_CTRL, RTC_OSC_SEL, RTC_OSC_SEL);
+
+			/*
+			 * Set RTC oscillator to freq_out to freq_in/((N0*M0+N1*M1)/(M0+M1))
+			 * Enable clock_in gate of oscillator 24MHz
+			 * Set N0 to 733, N1 to 732
+			 */
+			reg_val = FIELD_PREP(RTC_OSCIN_IN_EN, 1)
+				  | FIELD_PREP(RTC_OSCIN_OUT_CFG, 1)
+				  | FIELD_PREP(RTC_OSCIN_OUT_N0M0, RTC_OSCIN_OUT_32K_N0)
+				  | FIELD_PREP(RTC_OSCIN_OUT_N1M1, RTC_OSCIN_OUT_32K_N1);
+			regmap_write_bits(rtc->map, RTC_OSCIN_CTRL0, RTC_OSCIN_IN_EN
+					  | RTC_OSCIN_OUT_CFG | RTC_OSCIN_OUT_N0M0
+					  | RTC_OSCIN_OUT_N1M1, reg_val);
+
+			/* Set M0 to 2, M1 to 3, so freq_out = 32768 Hz*/
+			reg_val = FIELD_PREP(RTC_OSCIN_OUT_N0M0, RTC_OSCIN_OUT_32K_M0)
+				  | FIELD_PREP(RTC_OSCIN_OUT_N1M1, RTC_OSCIN_OUT_32K_M1);
+			regmap_write_bits(rtc->map, RTC_OSCIN_CTRL1, RTC_OSCIN_OUT_N0M0
+					  | RTC_OSCIN_OUT_N1M1, reg_val);
+		} else {
+			/* select 32K oscillator */
+			regmap_write_bits(rtc->map, RTC_CTRL, RTC_OSC_SEL, 0);
+		}
+	}
+	regmap_write_bits(rtc->map, RTC_INT_MASK,
+			  RTC_ALRM0_IRQ_MSK, RTC_ALRM0_IRQ_MSK);
+	regmap_write_bits(rtc->map, RTC_CTRL, RTC_ALRM0_EN, 0);
+}
+
+static int aml_rtc_probe(struct platform_device *pdev)
+{
+	struct aml_rtc_data *rtc;
+	void __iomem *base;
+	int ret = 0;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->config = of_device_get_match_data(&pdev->dev);
+	if (!rtc->config)
+		return -ENODEV;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base)) {
+		dev_err_probe(&pdev->dev, PTR_ERR(base), "resource ioremap failed\n");
+		return PTR_ERR(base);
+	}
+
+	rtc->map = devm_regmap_init_mmio(&pdev->dev, base, &aml_rtc_regmap_config);
+	if (IS_ERR(rtc->map)) {
+		dev_err_probe(&pdev->dev, PTR_ERR(rtc->map), "regmap init failed\n");
+		return PTR_ERR(rtc->map);
+	}
+
+	rtc->irq = platform_get_irq(pdev, 0);
+	if (rtc->irq < 0)
+		return rtc->irq;
+
+	rtc->rtc_clk = devm_clk_get(&pdev->dev, "osc");
+	if (IS_ERR(rtc->rtc_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_clk),
+				     "failed to find rtc clock\n");
+	if (clk_get_rate(rtc->rtc_clk) != OSC_32K && clk_get_rate(rtc->rtc_clk) != OSC_24M) {
+		dev_err_probe(&pdev->dev, -EINVAL, "Invalid clock configuration\n");
+		return -EINVAL;
+	}
+
+	rtc->sys_clk = devm_clk_get(&pdev->dev, "sys");
+	if (IS_ERR(rtc->sys_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->sys_clk),
+				     "failed to get rtc sys clk\n");
+	ret = clk_prepare_enable(rtc->sys_clk);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "Failed to enable clk!\n");
+		return ret;
+	}
+
+	aml_rtc_init(rtc);
+
+	device_init_wakeup(&pdev->dev, 1);
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtc_dev)) {
+		ret = PTR_ERR(rtc->rtc_dev);
+		goto err_clk;
+	}
+
+	ret = devm_request_irq(&pdev->dev, rtc->irq, aml_rtc_handler,
+			       IRQF_ONESHOT, "aml-rtc alarm", rtc);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "IRQ%d request failed, ret = %d\n",
+			      rtc->irq, ret);
+		goto err_clk;
+	}
+
+	rtc->rtc_dev->ops = &aml_rtc_ops;
+	rtc->rtc_dev->range_min = 0;
+	rtc->rtc_dev->range_max = U32_MAX;
+
+	ret = devm_rtc_register_device(rtc->rtc_dev);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "Failed to register RTC device: %d\n", ret);
+		goto err_clk;
+	}
+
+	return 0;
+err_clk:
+	clk_disable_unprepare(rtc->sys_clk);
+
+	return ret;
+}
+
+static int aml_rtc_suspend(struct device *dev)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(rtc->irq);
+
+	return 0;
+}
+
+static int aml_rtc_resume(struct device *dev)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(rtc->irq);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(aml_rtc_pm_ops,
+			 aml_rtc_suspend, aml_rtc_resume);
+
+static int aml_rtc_remove(struct platform_device *pdev)
+{
+	struct aml_rtc_data *rtc = dev_get_drvdata(&pdev->dev);
+
+	/* disable RTC */
+	regmap_write_bits(rtc->map, RTC_CTRL, RTC_ENABLE, 0);
+	clk_disable_unprepare(rtc->sys_clk);
+	device_init_wakeup(&pdev->dev, 0);
+
+	return 0;
+}
+
+static const struct aml_rtc_config a5_rtc_config = {
+};
+
+static const struct aml_rtc_config a4_rtc_config = {
+	.gray_stored = true,
+};
+
+static const struct of_device_id aml_rtc_device_id[] = {
+	{
+		.compatible = "amlogic,a4-rtc",
+		.data = &a4_rtc_config,
+	},
+	{
+		.compatible = "amlogic,a5-rtc",
+		.data = &a5_rtc_config,
+	},
+};
+MODULE_DEVICE_TABLE(of, aml_rtc_device_id);
+
+static struct platform_driver aml_rtc_driver = {
+	.probe = aml_rtc_probe,
+	.remove = aml_rtc_remove,
+	.driver = {
+		.name = "aml-rtc",
+		.pm = &aml_rtc_pm_ops,
+		.of_match_table = aml_rtc_device_id,
+	},
+};
+
+module_platform_driver(aml_rtc_driver);
+MODULE_DESCRIPTION("Amlogic RTC driver");
+MODULE_AUTHOR("Yiting Deng <yiting.deng@amlogic.com>");
+MODULE_LICENSE("GPL");