drivers/rtc/rtc-hym8563.c - pub/scm/linux/kernel/git/stable/linux-stable-rc - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Haoyu HYM8563 RTC driver
  *
  * Copyright (C) 2013 MundoReader S.L.
  * Author: Heiko Stuebner <heiko@sntech.de>
  *
  * based on rtc-HYM8563
  * Copyright (C) 2010 ROCKCHIP, Inc.
  */

 #include <linux/module.h>
 #include <linux/clk-provider.h>
 #include <linux/i2c.h>
 #include <linux/bcd.h>
 #include <linux/rtc.h>

 #define HYM8563_CTL1		0x00
 #define HYM8563_CTL1_TEST	BIT(7)
 #define HYM8563_CTL1_STOP	BIT(5)
 #define HYM8563_CTL1_TESTC	BIT(3)

 #define HYM8563_CTL2		0x01
 #define HYM8563_CTL2_TI_TP	BIT(4)
 #define HYM8563_CTL2_AF		BIT(3)
 #define HYM8563_CTL2_TF		BIT(2)
 #define HYM8563_CTL2_AIE	BIT(1)
 #define HYM8563_CTL2_TIE	BIT(0)

 #define HYM8563_SEC		0x02
 #define HYM8563_SEC_VL		BIT(7)
 #define HYM8563_SEC_MASK	0x7f

 #define HYM8563_MIN		0x03
 #define HYM8563_MIN_MASK	0x7f

 #define HYM8563_HOUR		0x04
 #define HYM8563_HOUR_MASK	0x3f

 #define HYM8563_DAY		0x05
 #define HYM8563_DAY_MASK	0x3f

 #define HYM8563_WEEKDAY		0x06
 #define HYM8563_WEEKDAY_MASK	0x07

 #define HYM8563_MONTH		0x07
 #define HYM8563_MONTH_CENTURY	BIT(7)
 #define HYM8563_MONTH_MASK	0x1f

 #define HYM8563_YEAR		0x08

 #define HYM8563_ALM_MIN		0x09
 #define HYM8563_ALM_HOUR	0x0a
 #define HYM8563_ALM_DAY		0x0b
 #define HYM8563_ALM_WEEK	0x0c

 /* Each alarm check can be disabled by setting this bit in the register */
 #define HYM8563_ALM_BIT_DISABLE	BIT(7)

 #define HYM8563_CLKOUT		0x0d
 #define HYM8563_CLKOUT_ENABLE	BIT(7)
 #define HYM8563_CLKOUT_32768	0
 #define HYM8563_CLKOUT_1024	1
 #define HYM8563_CLKOUT_32	2
 #define HYM8563_CLKOUT_1	3
 #define HYM8563_CLKOUT_MASK	3

 #define HYM8563_TMR_CTL		0x0e
 #define HYM8563_TMR_CTL_ENABLE	BIT(7)
 #define HYM8563_TMR_CTL_4096	0
 #define HYM8563_TMR_CTL_64	1
 #define HYM8563_TMR_CTL_1	2
 #define HYM8563_TMR_CTL_1_60	3
 #define HYM8563_TMR_CTL_MASK	3

 #define HYM8563_TMR_CNT		0x0f

 struct hym8563 {
 	struct i2c_client	*client;
 	struct rtc_device	*rtc;
 #ifdef CONFIG_COMMON_CLK
 	struct clk_hw		clkout_hw;
 #endif
 };

 /*
  * RTC handling
  */

 static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	u8 buf[7];
 	int ret;

 	ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf);
 	if (ret < 0)
 		return ret;

 	if (buf[0] & HYM8563_SEC_VL) {
 		dev_warn(&client->dev,
 			 "no valid clock/calendar values available\n");
 		return -EINVAL;
 	}

 	tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
 	tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
 	tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
 	tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
 	tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
 	tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
 	tm->tm_year = bcd2bin(buf[6]) + 100;

 	return 0;
 }

 static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	u8 buf[7];
 	int ret;

 	/* Years >= 2100 are to far in the future, 19XX is to early */
 	if (tm->tm_year < 100 || tm->tm_year >= 200)
 		return -EINVAL;

 	buf[0] = bin2bcd(tm->tm_sec);
 	buf[1] = bin2bcd(tm->tm_min);
 	buf[2] = bin2bcd(tm->tm_hour);
 	buf[3] = bin2bcd(tm->tm_mday);
 	buf[4] = bin2bcd(tm->tm_wday);
 	buf[5] = bin2bcd(tm->tm_mon + 1);

 	/*
 	 * While the HYM8563 has a century flag in the month register,
 	 * it does not seem to carry it over a subsequent write/read.
 	 * So we'll limit ourself to 100 years, starting at 2000 for now.
 	 */
 	buf[6] = bin2bcd(tm->tm_year - 100);

 	/*
 	 * CTL1 only contains TEST-mode bits apart from stop,
 	 * so no need to read the value first
 	 */
 	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
 						HYM8563_CTL1_STOP);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 static int hym8563_rtc_alarm_irq_enable(struct device *dev,
 					unsigned int enabled)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int data;

 	data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (data < 0)
 		return data;

 	if (enabled)
 		data |= HYM8563_CTL2_AIE;
 	else
 		data &= ~HYM8563_CTL2_AIE;

 	return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 };

 static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct rtc_time *alm_tm = &alm->time;
 	u8 buf[4];
 	int ret;

 	ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 	if (ret < 0)
 		return ret;

 	/* The alarm only has a minute accuracy */
 	alm_tm->tm_sec = 0;

 	alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
 					-1 :
 					bcd2bin(buf[0] & HYM8563_MIN_MASK);
 	alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
 					-1 :
 					bcd2bin(buf[1] & HYM8563_HOUR_MASK);
 	alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
 					-1 :
 					bcd2bin(buf[2] & HYM8563_DAY_MASK);
 	alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
 					-1 :
 					bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);

 	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (ret < 0)
 		return ret;

 	if (ret & HYM8563_CTL2_AIE)
 		alm->enabled = 1;

 	return 0;
 }

 static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct rtc_time *alm_tm = &alm->time;
 	u8 buf[4];
 	int ret;

 	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (ret < 0)
 		return ret;

 	ret &= ~HYM8563_CTL2_AIE;

 	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 	if (ret < 0)
 		return ret;

 	buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
 			bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;

 	buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
 			bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;

 	buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
 			bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;

 	buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
 			bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;

 	ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
 	if (ret < 0)
 		return ret;

 	return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
 }

 static const struct rtc_class_ops hym8563_rtc_ops = {
 	.read_time		= hym8563_rtc_read_time,
 	.set_time		= hym8563_rtc_set_time,
 	.alarm_irq_enable	= hym8563_rtc_alarm_irq_enable,
 	.read_alarm		= hym8563_rtc_read_alarm,
 	.set_alarm		= hym8563_rtc_set_alarm,
 };

 /*
  * Handling of the clkout
  */

 #ifdef CONFIG_COMMON_CLK
 #define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)

 static int clkout_rates[] = {
 	32768,
 	1024,
 	32,
 	1,
 };

 static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
 						unsigned long parent_rate)
 {
 	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 	struct i2c_client *client = hym8563->client;
 	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

 	if (ret < 0)
 		return 0;

 	ret &= HYM8563_CLKOUT_MASK;
 	return clkout_rates[ret];
 }

 static int hym8563_clkout_determine_rate(struct clk_hw *hw,
 					 struct clk_rate_request *req)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 		if (clkout_rates[i] <= req->rate) {
 			req->rate = clkout_rates[i];

 			return 0;
 		}

 	req->rate = clkout_rates[0];

 	return 0;
 }

 static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 				   unsigned long parent_rate)
 {
 	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 	struct i2c_client *client = hym8563->client;
 	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
 	int i;

 	if (ret < 0)
 		return ret;

 	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 		if (clkout_rates[i] == rate) {
 			ret &= ~HYM8563_CLKOUT_MASK;
 			ret |= i;
 			return i2c_smbus_write_byte_data(client,
 							 HYM8563_CLKOUT, ret);
 		}

 	return -EINVAL;
 }

 static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
 {
 	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 	struct i2c_client *client = hym8563->client;
 	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

 	if (ret < 0)
 		return ret;

 	if (enable)
 		ret |= HYM8563_CLKOUT_ENABLE;
 	else
 		ret &= ~HYM8563_CLKOUT_ENABLE;

 	return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
 }

 static int hym8563_clkout_prepare(struct clk_hw *hw)
 {
 	return hym8563_clkout_control(hw, 1);
 }

 static void hym8563_clkout_unprepare(struct clk_hw *hw)
 {
 	hym8563_clkout_control(hw, 0);
 }

 static int hym8563_clkout_is_prepared(struct clk_hw *hw)
 {
 	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
 	struct i2c_client *client = hym8563->client;
 	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

 	if (ret < 0)
 		return ret;

 	return !!(ret & HYM8563_CLKOUT_ENABLE);
 }

 static const struct clk_ops hym8563_clkout_ops = {
 	.prepare = hym8563_clkout_prepare,
 	.unprepare = hym8563_clkout_unprepare,
 	.is_prepared = hym8563_clkout_is_prepared,
 	.recalc_rate = hym8563_clkout_recalc_rate,
 	.determine_rate = hym8563_clkout_determine_rate,
 	.set_rate = hym8563_clkout_set_rate,
 };

 static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563)
 {
 	struct i2c_client *client = hym8563->client;
 	struct device_node *node = client->dev.of_node;
 	struct clk *clk;
 	struct clk_init_data init;
 	int ret;

 	ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
 						0);
 	if (ret < 0)
 		return ERR_PTR(ret);

 	init.name = "hym8563-clkout";
 	init.ops = &hym8563_clkout_ops;
 	init.flags = 0;
 	init.parent_names = NULL;
 	init.num_parents = 0;
 	hym8563->clkout_hw.init = &init;

 	/* optional override of the clockname */
 	of_property_read_string(node, "clock-output-names", &init.name);

 	/* register the clock */
 	clk = clk_register(&client->dev, &hym8563->clkout_hw);

 	if (!IS_ERR(clk))
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);

 	return clk;
 }
 #endif

 /*
  * The alarm interrupt is implemented as a level-low interrupt in the
  * hym8563, while the timer interrupt uses a falling edge.
  * We don't use the timer at all, so the interrupt is requested to
  * use the level-low trigger.
  */
 static irqreturn_t hym8563_irq(int irq, void *dev_id)
 {
 	struct hym8563 *hym8563 = (struct hym8563 *)dev_id;
 	struct i2c_client *client = hym8563->client;
 	int data, ret;

 	rtc_lock(hym8563->rtc);

 	/* Clear the alarm flag */

 	data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (data < 0) {
 		dev_err(&client->dev, "%s: error reading i2c data %d\n",
 			__func__, data);
 		goto out;
 	}

 	data &= ~HYM8563_CTL2_AF;

 	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
 	if (ret < 0) {
 		dev_err(&client->dev, "%s: error writing i2c data %d\n",
 			__func__, ret);
 	}

 out:
 	rtc_unlock(hym8563->rtc);
 	return IRQ_HANDLED;
 }

 static int hym8563_init_device(struct i2c_client *client)
 {
 	int ret;

 	/* Clear stop flag if present */
 	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
 	if (ret < 0)
 		return ret;

 	/* Disable alarm and timer interrupts */
 	ret &= ~HYM8563_CTL2_AIE;
 	ret &= ~HYM8563_CTL2_TIE;

 	/* Clear any pending alarm and timer flags */
 	if (ret & HYM8563_CTL2_AF)
 		ret &= ~HYM8563_CTL2_AF;

 	if (ret & HYM8563_CTL2_TF)
 		ret &= ~HYM8563_CTL2_TF;

 	ret &= ~HYM8563_CTL2_TI_TP;

 	return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
 }

 #ifdef CONFIG_PM_SLEEP
 static int hym8563_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;

 	if (device_may_wakeup(dev)) {
 		ret = enable_irq_wake(client->irq);
 		if (ret) {
 			dev_err(dev, "enable_irq_wake failed, %d\n", ret);
 			return ret;
 		}
 	}

 	return 0;
 }

 static int hym8563_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);

 	if (device_may_wakeup(dev))
 		disable_irq_wake(client->irq);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);

 static int hym8563_probe(struct i2c_client *client)
 {
 	struct hym8563 *hym8563;
 	int ret;

 	hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
 	if (!hym8563)
 		return -ENOMEM;

 	hym8563->rtc = devm_rtc_allocate_device(&client->dev);
 	if (IS_ERR(hym8563->rtc))
 		return PTR_ERR(hym8563->rtc);

 	hym8563->client = client;
 	i2c_set_clientdata(client, hym8563);

 	ret = hym8563_init_device(client);
 	if (ret) {
 		dev_err(&client->dev, "could not init device, %d\n", ret);
 		return ret;
 	}

 	if (client->irq > 0) {
 		unsigned long irqflags = IRQF_TRIGGER_LOW;

 		if (dev_fwnode(&client->dev))
 			irqflags = 0;

 		ret = devm_request_threaded_irq(&client->dev, client->irq,
 						NULL, hym8563_irq,
 						irqflags | IRQF_ONESHOT,
 						client->name, hym8563);
 		if (ret < 0) {
 			dev_err(&client->dev, "irq %d request failed, %d\n",
 				client->irq, ret);
 			return ret;
 		}
 	}

 	if (client->irq > 0 ||
 	    device_property_read_bool(&client->dev, "wakeup-source")) {
 		device_init_wakeup(&client->dev, true);
 	}

 	/* check state of calendar information */
 	ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
 	if (ret < 0)
 		return ret;

 	dev_dbg(&client->dev, "rtc information is %s\n",
 		(ret & HYM8563_SEC_VL) ? "invalid" : "valid");

 	hym8563->rtc->ops = &hym8563_rtc_ops;
 	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, hym8563->rtc->features);
 	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, hym8563->rtc->features);

 #ifdef CONFIG_COMMON_CLK
 	hym8563_clkout_register_clk(hym8563);
 #endif

 	return devm_rtc_register_device(hym8563->rtc);
 }

 static const struct i2c_device_id hym8563_id[] = {
 	{ "hym8563" },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, hym8563_id);

 static const struct of_device_id hym8563_dt_idtable[] = {
 	{ .compatible = "haoyu,hym8563" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);

 static struct i2c_driver hym8563_driver = {
 	.driver		= {
 		.name	= "rtc-hym8563",
 		.pm	= &hym8563_pm_ops,
 		.of_match_table	= hym8563_dt_idtable,
 	},
 	.probe		= hym8563_probe,
 	.id_table	= hym8563_id,
 };

 module_i2c_driver(hym8563_driver);

 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 MODULE_DESCRIPTION("HYM8563 RTC driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Haoyu HYM8563 RTC driver
	*
	* Copyright (C) 2013 MundoReader S.L.
	* Author: Heiko Stuebner <heiko@sntech.de>
	*
	* based on rtc-HYM8563
	* Copyright (C) 2010 ROCKCHIP, Inc.
	*/

	#include <linux/module.h>
	#include <linux/clk-provider.h>
	#include <linux/i2c.h>
	#include <linux/bcd.h>
	#include <linux/rtc.h>

	#define HYM8563_CTL1 0x00
	#define HYM8563_CTL1_TEST BIT(7)
	#define HYM8563_CTL1_STOP BIT(5)
	#define HYM8563_CTL1_TESTC BIT(3)

	#define HYM8563_CTL2 0x01
	#define HYM8563_CTL2_TI_TP BIT(4)
	#define HYM8563_CTL2_AF BIT(3)
	#define HYM8563_CTL2_TF BIT(2)
	#define HYM8563_CTL2_AIE BIT(1)
	#define HYM8563_CTL2_TIE BIT(0)

	#define HYM8563_SEC 0x02
	#define HYM8563_SEC_VL BIT(7)
	#define HYM8563_SEC_MASK 0x7f

	#define HYM8563_MIN 0x03
	#define HYM8563_MIN_MASK 0x7f

	#define HYM8563_HOUR 0x04
	#define HYM8563_HOUR_MASK 0x3f

	#define HYM8563_DAY 0x05
	#define HYM8563_DAY_MASK 0x3f

	#define HYM8563_WEEKDAY 0x06
	#define HYM8563_WEEKDAY_MASK 0x07

	#define HYM8563_MONTH 0x07
	#define HYM8563_MONTH_CENTURY BIT(7)
	#define HYM8563_MONTH_MASK 0x1f

	#define HYM8563_YEAR 0x08

	#define HYM8563_ALM_MIN 0x09
	#define HYM8563_ALM_HOUR 0x0a
	#define HYM8563_ALM_DAY 0x0b
	#define HYM8563_ALM_WEEK 0x0c

	/* Each alarm check can be disabled by setting this bit in the register */
	#define HYM8563_ALM_BIT_DISABLE BIT(7)

	#define HYM8563_CLKOUT 0x0d
	#define HYM8563_CLKOUT_ENABLE BIT(7)
	#define HYM8563_CLKOUT_32768 0
	#define HYM8563_CLKOUT_1024 1
	#define HYM8563_CLKOUT_32 2
	#define HYM8563_CLKOUT_1 3
	#define HYM8563_CLKOUT_MASK 3

	#define HYM8563_TMR_CTL 0x0e
	#define HYM8563_TMR_CTL_ENABLE BIT(7)
	#define HYM8563_TMR_CTL_4096 0
	#define HYM8563_TMR_CTL_64 1
	#define HYM8563_TMR_CTL_1 2
	#define HYM8563_TMR_CTL_1_60 3
	#define HYM8563_TMR_CTL_MASK 3

	#define HYM8563_TMR_CNT 0x0f

	struct hym8563 {
	struct i2c_client *client;
	struct rtc_device *rtc;
	#ifdef CONFIG_COMMON_CLK
	struct clk_hw clkout_hw;
	#endif
	};

	/*
	* RTC handling
	*/

	static int hym8563_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	u8 buf[7];
	int ret;

	ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf);
	if (ret < 0)
	return ret;

	if (buf[0] & HYM8563_SEC_VL) {
	dev_warn(&client->dev,
	"no valid clock/calendar values available\n");
	return -EINVAL;
	}

	tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK);
	tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK);
	tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK);
	tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK);
	tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */
	tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */
	tm->tm_year = bcd2bin(buf[6]) + 100;

	return 0;
	}

	static int hym8563_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	u8 buf[7];
	int ret;

	/* Years >= 2100 are to far in the future, 19XX is to early */
	if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
	return -EINVAL;

	buf[0] = bin2bcd(tm->tm_sec);
	buf[1] = bin2bcd(tm->tm_min);
	buf[2] = bin2bcd(tm->tm_hour);
	buf[3] = bin2bcd(tm->tm_mday);
	buf[4] = bin2bcd(tm->tm_wday);
	buf[5] = bin2bcd(tm->tm_mon + 1);

	/*
	* While the HYM8563 has a century flag in the month register,
	* it does not seem to carry it over a subsequent write/read.
	* So we'll limit ourself to 100 years, starting at 2000 for now.
	*/
	buf[6] = bin2bcd(tm->tm_year - 100);

	/*
	* CTL1 only contains TEST-mode bits apart from stop,
	* so no need to read the value first
	*/
	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1,
	HYM8563_CTL1_STOP);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
	if (ret < 0)
	return ret;

	return 0;
	}

	static int hym8563_rtc_alarm_irq_enable(struct device *dev,
	unsigned int enabled)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int data;

	data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
	if (data < 0)
	return data;

	if (enabled)
	data \|= HYM8563_CTL2_AIE;
	else
	data &= ~HYM8563_CTL2_AIE;

	return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
	};

	static int hym8563_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct rtc_time *alm_tm = &alm->time;
	u8 buf[4];
	int ret;

	ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
	if (ret < 0)
	return ret;

	/* The alarm only has a minute accuracy */
	alm_tm->tm_sec = 0;

	alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ?
	-1 :
	bcd2bin(buf[0] & HYM8563_MIN_MASK);
	alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ?
	-1 :
	bcd2bin(buf[1] & HYM8563_HOUR_MASK);
	alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ?
	-1 :
	bcd2bin(buf[2] & HYM8563_DAY_MASK);
	alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ?
	-1 :
	bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK);

	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
	if (ret < 0)
	return ret;

	if (ret & HYM8563_CTL2_AIE)
	alm->enabled = 1;

	return 0;
	}

	static int hym8563_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct rtc_time *alm_tm = &alm->time;
	u8 buf[4];
	int ret;

	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
	if (ret < 0)
	return ret;

	ret &= ~HYM8563_CTL2_AIE;

	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
	if (ret < 0)
	return ret;

	buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ?
	bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE;

	buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ?
	bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE;

	buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ?
	bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE;

	buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ?
	bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE;

	ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf);
	if (ret < 0)
	return ret;

	return hym8563_rtc_alarm_irq_enable(dev, alm->enabled);
	}

	static const struct rtc_class_ops hym8563_rtc_ops = {
	.read_time = hym8563_rtc_read_time,
	.set_time = hym8563_rtc_set_time,
	.alarm_irq_enable = hym8563_rtc_alarm_irq_enable,
	.read_alarm = hym8563_rtc_read_alarm,
	.set_alarm = hym8563_rtc_set_alarm,
	};

	/*
	* Handling of the clkout
	*/

	#ifdef CONFIG_COMMON_CLK
	#define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw)

	static int clkout_rates[] = {
	32768,
	1024,
	32,
	1,
	};

	static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw,
	unsigned long parent_rate)
	{
	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
	struct i2c_client *client = hym8563->client;
	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

	if (ret < 0)
	return 0;

	ret &= HYM8563_CLKOUT_MASK;
	return clkout_rates[ret];
	}

	static int hym8563_clkout_determine_rate(struct clk_hw *hw,
	struct clk_rate_request *req)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
	if (clkout_rates[i] <= req->rate) {
	req->rate = clkout_rates[i];

	return 0;
	}

	req->rate = clkout_rates[0];

	return 0;
	}

	static int hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
	unsigned long parent_rate)
	{
	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
	struct i2c_client *client = hym8563->client;
	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);
	int i;

	if (ret < 0)
	return ret;

	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
	if (clkout_rates[i] == rate) {
	ret &= ~HYM8563_CLKOUT_MASK;
	ret \|= i;
	return i2c_smbus_write_byte_data(client,
	HYM8563_CLKOUT, ret);
	}

	return -EINVAL;
	}

	static int hym8563_clkout_control(struct clk_hw *hw, bool enable)
	{
	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
	struct i2c_client *client = hym8563->client;
	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

	if (ret < 0)
	return ret;

	if (enable)
	ret \|= HYM8563_CLKOUT_ENABLE;
	else
	ret &= ~HYM8563_CLKOUT_ENABLE;

	return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret);
	}

	static int hym8563_clkout_prepare(struct clk_hw *hw)
	{
	return hym8563_clkout_control(hw, 1);
	}

	static void hym8563_clkout_unprepare(struct clk_hw *hw)
	{
	hym8563_clkout_control(hw, 0);
	}

	static int hym8563_clkout_is_prepared(struct clk_hw *hw)
	{
	struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw);
	struct i2c_client *client = hym8563->client;
	int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT);

	if (ret < 0)
	return ret;

	return !!(ret & HYM8563_CLKOUT_ENABLE);
	}

	static const struct clk_ops hym8563_clkout_ops = {
	.prepare = hym8563_clkout_prepare,
	.unprepare = hym8563_clkout_unprepare,
	.is_prepared = hym8563_clkout_is_prepared,
	.recalc_rate = hym8563_clkout_recalc_rate,
	.determine_rate = hym8563_clkout_determine_rate,
	.set_rate = hym8563_clkout_set_rate,
	};

	static struct clk hym8563_clkout_register_clk(struct hym8563 hym8563)
	{
	struct i2c_client *client = hym8563->client;
	struct device_node *node = client->dev.of_node;
	struct clk *clk;
	struct clk_init_data init;
	int ret;

	ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT,
	0);
	if (ret < 0)
	return ERR_PTR(ret);

	init.name = "hym8563-clkout";
	init.ops = &hym8563_clkout_ops;
	init.flags = 0;
	init.parent_names = NULL;
	init.num_parents = 0;
	hym8563->clkout_hw.init = &init;

	/* optional override of the clockname */
	of_property_read_string(node, "clock-output-names", &init.name);

	/* register the clock */
	clk = clk_register(&client->dev, &hym8563->clkout_hw);

	if (!IS_ERR(clk))
	of_clk_add_provider(node, of_clk_src_simple_get, clk);

	return clk;
	}
	#endif

	/*
	* The alarm interrupt is implemented as a level-low interrupt in the
	* hym8563, while the timer interrupt uses a falling edge.
	* We don't use the timer at all, so the interrupt is requested to
	* use the level-low trigger.
	*/
	static irqreturn_t hym8563_irq(int irq, void *dev_id)
	{
	struct hym8563 hym8563 = (struct hym8563 )dev_id;
	struct i2c_client *client = hym8563->client;
	int data, ret;

	rtc_lock(hym8563->rtc);

	/* Clear the alarm flag */

	data = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
	if (data < 0) {
	dev_err(&client->dev, "%s: error reading i2c data %d\n",
	__func__, data);
	goto out;
	}

	data &= ~HYM8563_CTL2_AF;

	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data);
	if (ret < 0) {
	dev_err(&client->dev, "%s: error writing i2c data %d\n",
	__func__, ret);
	}

	out:
	rtc_unlock(hym8563->rtc);
	return IRQ_HANDLED;
	}

	static int hym8563_init_device(struct i2c_client *client)
	{
	int ret;

	/* Clear stop flag if present */
	ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2);
	if (ret < 0)
	return ret;

	/* Disable alarm and timer interrupts */
	ret &= ~HYM8563_CTL2_AIE;
	ret &= ~HYM8563_CTL2_TIE;

	/* Clear any pending alarm and timer flags */
	if (ret & HYM8563_CTL2_AF)
	ret &= ~HYM8563_CTL2_AF;

	if (ret & HYM8563_CTL2_TF)
	ret &= ~HYM8563_CTL2_TF;

	ret &= ~HYM8563_CTL2_TI_TP;

	return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret);
	}

	#ifdef CONFIG_PM_SLEEP
	static int hym8563_suspend(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	if (device_may_wakeup(dev)) {
	ret = enable_irq_wake(client->irq);
	if (ret) {
	dev_err(dev, "enable_irq_wake failed, %d\n", ret);
	return ret;
	}
	}

	return 0;
	}

	static int hym8563_resume(struct device *dev)
	{
	struct i2c_client *client = to_i2c_client(dev);

	if (device_may_wakeup(dev))
	disable_irq_wake(client->irq);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume);

	static int hym8563_probe(struct i2c_client *client)
	{
	struct hym8563 *hym8563;
	int ret;

	hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
	if (!hym8563)
	return -ENOMEM;

	hym8563->rtc = devm_rtc_allocate_device(&client->dev);
	if (IS_ERR(hym8563->rtc))
	return PTR_ERR(hym8563->rtc);

	hym8563->client = client;
	i2c_set_clientdata(client, hym8563);

	ret = hym8563_init_device(client);
	if (ret) {
	dev_err(&client->dev, "could not init device, %d\n", ret);
	return ret;
	}

	if (client->irq > 0) {
	unsigned long irqflags = IRQF_TRIGGER_LOW;

	if (dev_fwnode(&client->dev))
	irqflags = 0;

	ret = devm_request_threaded_irq(&client->dev, client->irq,
	NULL, hym8563_irq,
	irqflags \| IRQF_ONESHOT,
	client->name, hym8563);
	if (ret < 0) {
	dev_err(&client->dev, "irq %d request failed, %d\n",
	client->irq, ret);
	return ret;
	}
	}

	if (client->irq > 0 \|\|
	device_property_read_bool(&client->dev, "wakeup-source")) {
	device_init_wakeup(&client->dev, true);
	}

	/* check state of calendar information */
	ret = i2c_smbus_read_byte_data(client, HYM8563_SEC);
	if (ret < 0)
	return ret;

	dev_dbg(&client->dev, "rtc information is %s\n",
	(ret & HYM8563_SEC_VL) ? "invalid" : "valid");

	hym8563->rtc->ops = &hym8563_rtc_ops;
	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, hym8563->rtc->features);
	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, hym8563->rtc->features);

	#ifdef CONFIG_COMMON_CLK
	hym8563_clkout_register_clk(hym8563);
	#endif

	return devm_rtc_register_device(hym8563->rtc);
	}

	static const struct i2c_device_id hym8563_id[] = {
	{ "hym8563" },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, hym8563_id);

	static const struct of_device_id hym8563_dt_idtable[] = {
	{ .compatible = "haoyu,hym8563" },
	{},
	};
	MODULE_DEVICE_TABLE(of, hym8563_dt_idtable);

	static struct i2c_driver hym8563_driver = {
	.driver = {
	.name = "rtc-hym8563",
	.pm = &hym8563_pm_ops,
	.of_match_table = hym8563_dt_idtable,
	},
	.probe = hym8563_probe,
	.id_table = hym8563_id,
	};

	module_i2c_driver(hym8563_driver);

	MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
	MODULE_DESCRIPTION("HYM8563 RTC driver");
	MODULE_LICENSE("GPL");