1 files changed, 370 insertions, 185 deletions

diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
index 28c48b3c1946..2c63c0ffd05a 100644
--- a/drivers/rtc/rtc-pcf8523.c
+++ b/drivers/rtc/rtc-pcf8523.c
@@ -1,332 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Avionic Design GmbH
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/bcd.h>
+#include <linux/bitfield.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/rtc.h>
 #include <linux/of.h>
+#include <linux/pm_wakeirq.h>
 
-#define DRIVER_NAME "rtc-pcf8523"
+#define PCF8523_REG_CONTROL1 0x00
+#define PCF8523_CONTROL1_CAP_SEL BIT(7)
+#define PCF8523_CONTROL1_STOP    BIT(5)
+#define PCF8523_CONTROL1_AIE    BIT(1)
 
-#define REG_CONTROL1 0x00
-#define REG_CONTROL1_CAP_SEL (1 << 7)
-#define REG_CONTROL1_STOP    (1 << 5)
+#define PCF8523_REG_CONTROL2 0x01
+#define PCF8523_CONTROL2_AF BIT(3)
 
-#define REG_CONTROL3 0x02
-#define REG_CONTROL3_PM_BLD (1 << 7) /* battery low detection disabled */
-#define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */
-#define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */
-#define REG_CONTROL3_PM_MASK 0xe0
-#define REG_CONTROL3_BLF (1 << 2) /* battery low bit, read-only */
+#define PCF8523_REG_CONTROL3 0x02
+#define PCF8523_CONTROL3_PM  GENMASK(7, 5)
+#define PCF8523_PM_STANDBY   0x7
+#define PCF8523_CONTROL3_BLF BIT(2) /* battery low bit, read-only */
+#define PCF8523_CONTROL3_BSF BIT(3)
 
-#define REG_SECONDS  0x03
-#define REG_SECONDS_OS (1 << 7)
+#define PCF8523_REG_SECONDS  0x03
+#define PCF8523_SECONDS_OS BIT(7)
 
-#define REG_MINUTES  0x04
-#define REG_HOURS    0x05
-#define REG_DAYS     0x06
-#define REG_WEEKDAYS 0x07
-#define REG_MONTHS   0x08
-#define REG_YEARS    0x09
+#define PCF8523_REG_MINUTES  0x04
+#define PCF8523_REG_HOURS    0x05
+#define PCF8523_REG_DAYS     0x06
+#define PCF8523_REG_WEEKDAYS 0x07
+#define PCF8523_REG_MONTHS   0x08
+#define PCF8523_REG_YEARS    0x09
+
+#define PCF8523_REG_MINUTE_ALARM	0x0a
+#define PCF8523_REG_HOUR_ALARM		0x0b
+#define PCF8523_REG_DAY_ALARM		0x0c
+#define PCF8523_REG_WEEKDAY_ALARM	0x0d
+#define ALARM_DIS BIT(7)
+
+#define PCF8523_REG_OFFSET   0x0e
+#define PCF8523_OFFSET_MODE BIT(7)
+
+#define PCF8523_TMR_CLKOUT_CTRL 0x0f
 
 struct pcf8523 {
 	struct rtc_device *rtc;
+	struct regmap *regmap;
 };
 
-static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
+static int pcf8523_load_capacitance(struct pcf8523 *pcf8523, struct device_node *node)
 {
-	struct i2c_msg msgs[2];
-	u8 value = 0;
-	int err;
+	u32 load, value = 0;
+
+	load = 12500;
+	of_property_read_u32(node, "quartz-load-femtofarads", &load);
+
+	switch (load) {
+	default:
+		dev_warn(&pcf8523->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
+			 load);
+		fallthrough;
+	case 12500:
+		value = PCF8523_CONTROL1_CAP_SEL;
+		break;
+	case 7000:
+		break;
+	}
 
-	msgs[0].addr = client->addr;
-	msgs[0].flags = 0;
-	msgs[0].len = sizeof(reg);
-	msgs[0].buf = &reg;
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_CAP_SEL, value);
+}
 
-	msgs[1].addr = client->addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = sizeof(value);
-	msgs[1].buf = &value;
+static irqreturn_t pcf8523_irq(int irq, void *dev_id)
+{
+	struct pcf8523 *pcf8523 = dev_id;
+	u32 value;
+	int err;
 
-	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
 	if (err < 0)
-		return err;
+		return IRQ_HANDLED;
 
-	*valuep = value;
+	if (value & PCF8523_CONTROL2_AF) {
+		value &= ~PCF8523_CONTROL2_AF;
+		regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, value);
+		rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
 
-	return 0;
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
 }
 
-static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
+static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
-	u8 buffer[2] = { reg, value };
-	struct i2c_msg msg;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[10];
 	int err;
 
-	msg.addr = client->addr;
-	msg.flags = 0;
-	msg.len = sizeof(buffer);
-	msg.buf = buffer;
-
-	err = i2c_transfer(client->adapter, &msg, 1);
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_CONTROL1, regs,
+			       sizeof(regs));
 	if (err < 0)
 		return err;
 
+	if ((regs[0] & PCF8523_CONTROL1_STOP) || (regs[3] & PCF8523_SECONDS_OS))
+		return -EINVAL;
+
+	tm->tm_sec = bcd2bin(regs[3] & 0x7f);
+	tm->tm_min = bcd2bin(regs[4] & 0x7f);
+	tm->tm_hour = bcd2bin(regs[5] & 0x3f);
+	tm->tm_mday = bcd2bin(regs[6] & 0x3f);
+	tm->tm_wday = regs[7] & 0x7;
+	tm->tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
+	tm->tm_year = bcd2bin(regs[9]) + 100;
+
 	return 0;
 }
 
-static int pcf8523_select_capacitance(struct i2c_client *client, bool high)
+static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
-	u8 value;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[7];
 	int err;
 
-	err = pcf8523_read(client, REG_CONTROL1, &value);
+	err = regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, PCF8523_CONTROL1_STOP);
 	if (err < 0)
 		return err;
 
-	if (!high)
-		value &= ~REG_CONTROL1_CAP_SEL;
-	else
-		value |= REG_CONTROL1_CAP_SEL;
-
-	err = pcf8523_write(client, REG_CONTROL1, value);
-	if (err < 0)
+	/* This will purposely overwrite PCF8523_SECONDS_OS */
+	regs[0] = bin2bcd(tm->tm_sec);
+	regs[1] = bin2bcd(tm->tm_min);
+	regs[2] = bin2bcd(tm->tm_hour);
+	regs[3] = bin2bcd(tm->tm_mday);
+	regs[4] = tm->tm_wday;
+	regs[5] = bin2bcd(tm->tm_mon + 1);
+	regs[6] = bin2bcd(tm->tm_year - 100);
+
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_SECONDS, regs,
+				sizeof(regs));
+	if (err < 0) {
+		/*
+		 * If the time cannot be set, restart the RTC anyway. Note
+		 * that errors are ignored if the RTC cannot be started so
+		 * that we have a chance to propagate the original error.
+		 */
+		regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				   PCF8523_CONTROL1_STOP, 0);
 		return err;
+	}
 
-	return err;
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				 PCF8523_CONTROL1_STOP, 0);
 }
 
-static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
+static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
 {
-	u8 value;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[4];
+	u32 value;
 	int err;
 
-	err = pcf8523_read(client, REG_CONTROL3, &value);
+	err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+			       sizeof(regs));
 	if (err < 0)
 		return err;
 
-	value = (value & ~REG_CONTROL3_PM_MASK) | pm;
+	tm->time.tm_sec = 0;
+	tm->time.tm_min = bcd2bin(regs[0] & 0x7F);
+	tm->time.tm_hour = bcd2bin(regs[1] & 0x3F);
+	tm->time.tm_mday = bcd2bin(regs[2] & 0x3F);
+	tm->time.tm_wday = bcd2bin(regs[3] & 0x7);
+
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL1, &value);
+	if (err < 0)
+		return err;
+	tm->enabled = !!(value & PCF8523_CONTROL1_AIE);
 
-	err = pcf8523_write(client, REG_CONTROL3, value);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
 	if (err < 0)
 		return err;
+	tm->pending = !!(value & PCF8523_CONTROL2_AF);
 
 	return 0;
 }
 
-static int pcf8523_stop_rtc(struct i2c_client *client)
+static int pcf8523_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+
+	return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
+				  PCF8523_CONTROL1_AIE, enabled ?
+				  PCF8523_CONTROL1_AIE : 0);
+}
+
+static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
 {
-	u8 value;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 regs[5];
 	int err;
 
-	err = pcf8523_read(client, REG_CONTROL1, &value);
+	err = pcf8523_irq_enable(dev, 0);
+	if (err)
+		return err;
+
+	err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, 0);
 	if (err < 0)
 		return err;
 
-	value |= REG_CONTROL1_STOP;
+	regs[0] = bin2bcd(tm->time.tm_min);
+	regs[1] = bin2bcd(tm->time.tm_hour);
+	regs[2] = bin2bcd(tm->time.tm_mday);
+	regs[3] = ALARM_DIS;
 
-	err = pcf8523_write(client, REG_CONTROL1, value);
+	err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
+				sizeof(regs));
 	if (err < 0)
 		return err;
 
+	if (tm->enabled)
+		return pcf8523_irq_enable(dev, tm->enabled);
+
 	return 0;
 }
 
-static int pcf8523_start_rtc(struct i2c_client *client)
+static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
 {
-	u8 value;
-	int err;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	int ret;
+	u32 value;
+
+	switch (param->param) {
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (ret < 0)
+			return ret;
+
+		value = FIELD_GET(PCF8523_CONTROL3_PM, value);
+
+		switch (value) {
+		case 0x0:
+		case 0x4:
+			param->uvalue = RTC_BSM_LEVEL;
+			break;
+		case 0x1:
+		case 0x5:
+			param->uvalue = RTC_BSM_DIRECT;
+			break;
+		case PCF8523_PM_STANDBY:
+			param->uvalue = RTC_BSM_STANDBY;
+			break;
+		default:
+			param->uvalue = RTC_BSM_DISABLED;
+		}
+
+		break;
 
-	err = pcf8523_read(client, REG_CONTROL1, &value);
-	if (err < 0)
-		return err;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
 
-	value &= ~REG_CONTROL1_STOP;
+static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	u8 mode;
+
+	switch (param->param) {
+	case RTC_PARAM_BACKUP_SWITCH_MODE:
+		switch (param->uvalue) {
+		case RTC_BSM_DISABLED:
+			mode = 0x2;
+			break;
+		case RTC_BSM_DIRECT:
+			mode = 0x1;
+			break;
+		case RTC_BSM_LEVEL:
+			mode = 0x0;
+			break;
+		case RTC_BSM_STANDBY:
+			mode = PCF8523_PM_STANDBY;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					  PCF8523_CONTROL3_PM,
+					  FIELD_PREP(PCF8523_CONTROL3_PM, mode));
+
+		break;
 
-	err = pcf8523_write(client, REG_CONTROL1, value);
-	if (err < 0)
-		return err;
+	default:
+		return -EINVAL;
+	}
 
 	return 0;
 }
 
-static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
+static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
+			     unsigned long arg)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	u8 start = REG_SECONDS, regs[7];
-	struct i2c_msg msgs[2];
-	int err;
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	unsigned int flags = 0;
+	u32 value;
+	int ret;
 
-	msgs[0].addr = client->addr;
-	msgs[0].flags = 0;
-	msgs[0].len = 1;
-	msgs[0].buf = &start;
+	switch (cmd) {
+	case RTC_VL_READ:
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (ret < 0)
+			return ret;
 
-	msgs[1].addr = client->addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = sizeof(regs);
-	msgs[1].buf = regs;
+		if (value & PCF8523_CONTROL3_BLF)
+			flags |= RTC_VL_BACKUP_LOW;
 
-	err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
-	if (err < 0)
-		return err;
+		ret = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
+		if (ret < 0)
+			return ret;
 
-	if (regs[0] & REG_SECONDS_OS)
-		return -EINVAL;
+		if (value & PCF8523_SECONDS_OS)
+			flags |= RTC_VL_DATA_INVALID;
 
-	tm->tm_sec = bcd2bin(regs[0] & 0x7f);
-	tm->tm_min = bcd2bin(regs[1] & 0x7f);
-	tm->tm_hour = bcd2bin(regs[2] & 0x3f);
-	tm->tm_mday = bcd2bin(regs[3] & 0x3f);
-	tm->tm_wday = regs[4] & 0x7;
-	tm->tm_mon = bcd2bin(regs[5] & 0x1f) - 1;
-	tm->tm_year = bcd2bin(regs[6]) + 100;
+		return put_user(flags, (unsigned int __user *)arg);
 
-	return rtc_valid_tm(tm);
+	default:
+		return -ENOIOCTLCMD;
+	}
 }
 
-static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
+static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
 {
-	struct i2c_client *client = to_i2c_client(dev);
-	struct i2c_msg msg;
-	u8 regs[8];
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
 	int err;
+	u32 value;
+	s8 val;
 
-	/*
-	 * The hardware can only store values between 0 and 99 in it's YEAR
-	 * register (with 99 overflowing to 0 on increment).
-	 * After 2100-02-28 we could start interpreting the year to be in the
-	 * interval [2100, 2199], but there is no path to switch in a smooth way
-	 * because the chip handles YEAR=0x00 (and the out-of-spec
-	 * YEAR=0xa0) as a leap year, but 2100 isn't.
-	 */
-	if (tm->tm_year < 100 || tm->tm_year >= 200)
-		return -EINVAL;
-
-	err = pcf8523_stop_rtc(client);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_OFFSET, &value);
 	if (err < 0)
 		return err;
 
-	regs[0] = REG_SECONDS;
-	/* This will purposely overwrite REG_SECONDS_OS */
-	regs[1] = bin2bcd(tm->tm_sec);
-	regs[2] = bin2bcd(tm->tm_min);
-	regs[3] = bin2bcd(tm->tm_hour);
-	regs[4] = bin2bcd(tm->tm_mday);
-	regs[5] = tm->tm_wday;
-	regs[6] = bin2bcd(tm->tm_mon + 1);
-	regs[7] = bin2bcd(tm->tm_year - 100);
-
-	msg.addr = client->addr;
-	msg.flags = 0;
-	msg.len = sizeof(regs);
-	msg.buf = regs;
-
-	err = i2c_transfer(client->adapter, &msg, 1);
-	if (err < 0) {
-		/*
-		 * If the time cannot be set, restart the RTC anyway. Note
-		 * that errors are ignored if the RTC cannot be started so
-		 * that we have a chance to propagate the original error.
-		 */
-		pcf8523_start_rtc(client);
-		return err;
-	}
+	/* sign extend the 7-bit offset value */
+	val = value << 1;
+	*offset = (value & PCF8523_OFFSET_MODE ? 4069 : 4340) * (val >> 1);
 
-	return pcf8523_start_rtc(client);
+	return 0;
 }
 
-#ifdef CONFIG_RTC_INTF_DEV
-static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
-			     unsigned long arg)
+static int pcf8523_rtc_set_offset(struct device *dev, long offset)
+{
+	struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
+	long reg_m0, reg_m1;
+	u32 value;
+
+	reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
+	reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
+
+	if (abs(reg_m0 * 4340 - offset) < abs(reg_m1 * 4069 - offset))
+		value = reg_m0 & 0x7f;
+	else
+		value = (reg_m1 & 0x7f) | PCF8523_OFFSET_MODE;
+
+	return regmap_write(pcf8523->regmap, PCF8523_REG_OFFSET, value);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pcf8523_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	u8 value;
-	int ret = 0, err;
 
-	switch (cmd) {
-	case RTC_VL_READ:
-		err = pcf8523_read(client, REG_CONTROL3, &value);
-		if (err < 0)
-			return err;
+	if (client->irq > 0 && device_may_wakeup(dev))
+		enable_irq_wake(client->irq);
+
+	return 0;
+}
 
-		if (value & REG_CONTROL3_BLF)
-			ret = 1;
+static int pcf8523_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
 
-		if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
-			return -EFAULT;
+	if (client->irq > 0 && device_may_wakeup(dev))
+		disable_irq_wake(client->irq);
 
-		return 0;
-	default:
-		return -ENOIOCTLCMD;
-	}
+	return 0;
 }
-#else
-#define pcf8523_rtc_ioctl NULL
 #endif
 
+static SIMPLE_DEV_PM_OPS(pcf8523_pm, pcf8523_suspend, pcf8523_resume);
+
 static const struct rtc_class_ops pcf8523_rtc_ops = {
 	.read_time = pcf8523_rtc_read_time,
 	.set_time = pcf8523_rtc_set_time,
+	.read_alarm = pcf8523_rtc_read_alarm,
+	.set_alarm = pcf8523_rtc_set_alarm,
+	.alarm_irq_enable = pcf8523_irq_enable,
 	.ioctl = pcf8523_rtc_ioctl,
+	.read_offset = pcf8523_rtc_read_offset,
+	.set_offset = pcf8523_rtc_set_offset,
+	.param_get = pcf8523_param_get,
+	.param_set = pcf8523_param_set,
+};
+
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x13,
 };
 
-static int pcf8523_probe(struct i2c_client *client,
-			 const struct i2c_device_id *id)
+static int pcf8523_probe(struct i2c_client *client)
 {
-	struct pcf8523 *pcf;
+	struct pcf8523 *pcf8523;
+	struct rtc_device *rtc;
+	bool wakeup_source = false;
+	u32 value;
 	int err;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;
 
-	pcf = devm_kzalloc(&client->dev, sizeof(*pcf), GFP_KERNEL);
-	if (!pcf)
+	pcf8523 = devm_kzalloc(&client->dev, sizeof(struct pcf8523), GFP_KERNEL);
+	if (!pcf8523)
 		return -ENOMEM;
 
-	err = pcf8523_select_capacitance(client, true);
+	pcf8523->regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(pcf8523->regmap))
+		return PTR_ERR(pcf8523->regmap);
+
+	i2c_set_clientdata(client, pcf8523);
+
+	rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+	pcf8523->rtc = rtc;
+
+	err = pcf8523_load_capacitance(pcf8523, client->dev.of_node);
 	if (err < 0)
-		return err;
+		dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
+			 err);
 
-	err = pcf8523_set_pm(client, 0);
+	err = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
 	if (err < 0)
 		return err;
 
-	pcf->rtc = devm_rtc_device_register(&client->dev, DRIVER_NAME,
-				       &pcf8523_rtc_ops, THIS_MODULE);
-	if (IS_ERR(pcf->rtc))
-		return PTR_ERR(pcf->rtc);
+	if (value & PCF8523_SECONDS_OS) {
+		err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
+		if (err < 0)
+			return err;
 
-	i2c_set_clientdata(client, pcf);
+		if (FIELD_GET(PCF8523_CONTROL3_PM, value) == PCF8523_PM_STANDBY) {
+			err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL3,
+					   value & ~PCF8523_CONTROL3_PM);
+			if (err < 0)
+				return err;
+		}
+	}
 
-	return 0;
+	rtc->ops = &pcf8523_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+
+	if (client->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(&client->dev))
+			irqflags = 0;
+
+		err = regmap_write(pcf8523->regmap, PCF8523_TMR_CLKOUT_CTRL, 0x38);
+		if (err < 0)
+			return err;
+
+		err = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, pcf8523_irq,
+						IRQF_SHARED | IRQF_ONESHOT | irqflags,
+						dev_name(&rtc->dev), pcf8523);
+		if (err)
+			return err;
+
+		dev_pm_set_wake_irq(&client->dev, client->irq);
+	}
+
+	wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
+	if (client->irq > 0 || wakeup_source)
+		device_init_wakeup(&client->dev, true);
+
+	return devm_rtc_register_device(rtc);
 }
 
 static const struct i2c_device_id pcf8523_id[] = {
-	{ "pcf8523", 0 },
+	{ "pcf8523" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pcf8523_id);
 
-#ifdef CONFIG_OF
 static const struct of_device_id pcf8523_of_match[] = {
 	{ .compatible = "nxp,pcf8523" },
+	{ .compatible = "microcrystal,rv8523" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pcf8523_of_match);
-#endif
 
 static struct i2c_driver pcf8523_driver = {
 	.driver = {
-		.name = DRIVER_NAME,
-		.of_match_table = of_match_ptr(pcf8523_of_match),
+		.name = "rtc-pcf8523",
+		.of_match_table = pcf8523_of_match,
+		.pm = &pcf8523_pm,
 	},
 	.probe = pcf8523_probe,
 	.id_table = pcf8523_id,