// 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
  ");
  		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;
  
  	/*
  	 * The alarm has no seconds so deal with it
  	 */
  	if (alm_tm->tm_sec) {
  		alm_tm->tm_sec = 0;
  		alm_tm->tm_min++;
  		if (alm_tm->tm_min >= 60) {
  			alm_tm->tm_min = 0;
  			alm_tm->tm_hour++;
  			if (alm_tm->tm_hour >= 24) {
  				alm_tm->tm_hour = 0;
  				alm_tm->tm_mday++;
  				if (alm_tm->tm_mday > 31)
  					alm_tm->tm_mday = 0;
  			}
  		}
  	}
  
  	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 long hym8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
  				      unsigned long *prate)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
  		if (clkout_rates[i] <= rate)
  			return clkout_rates[i];
  
  	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,
  	.round_rate = hym8563_clkout_round_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;
  	struct mutex *lock = &hym8563->rtc->ops_lock;
  	int data, ret;
  
  	mutex_lock(lock);
  
  	/* 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
  ",
  			__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
  ",
  			__func__, ret);
  	}
  
  out:
  	mutex_unlock(lock);
  	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
  ", 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,
  			 const struct i2c_device_id *id)
  {
  	struct hym8563 *hym8563;
  	int ret;
  
  	hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL);
  	if (!hym8563)
  		return -ENOMEM;
  
  	hym8563->client = client;
  	i2c_set_clientdata(client, hym8563);
  
  	device_set_wakeup_capable(&client->dev, true);
  
  	ret = hym8563_init_device(client);
  	if (ret) {
  		dev_err(&client->dev, "could not init device, %d
  ", ret);
  		return ret;
  	}

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

  	}
  
  	/* 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
  ",

  		(ret & HYM8563_SEC_VL) ? "invalid" : "valid");

  
  	hym8563->rtc = devm_rtc_device_register(&client->dev, client->name,
  						&hym8563_rtc_ops, THIS_MODULE);
  	if (IS_ERR(hym8563->rtc))
  		return PTR_ERR(hym8563->rtc);

  	/* the hym8563 alarm only supports a minute accuracy */
  	hym8563->rtc->uie_unsupported = 1;

  #ifdef CONFIG_COMMON_CLK
  	hym8563_clkout_register_clk(hym8563);
  #endif
  
  	return 0;
  }
  
  static const struct i2c_device_id hym8563_id[] = {
  	{ "hym8563", 0 },
  	{},
  };
  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");