[linux.git] / drivers / rtc / rtc-s35390a.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Seiko Instruments S-35390A RTC Driver
 *
 * Copyright (c) 2007 Byron Bradley
 */

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/i2c.h>
#include <linux/bitrev.h>
#include <linux/bcd.h>
#include <linux/slab.h>
#include <linux/delay.h>

#define S35390A_CMD_STATUS1	0
#define S35390A_CMD_STATUS2	1
#define S35390A_CMD_TIME1	2
#define S35390A_CMD_TIME2	3
#define S35390A_CMD_INT2_REG1	5

#define S35390A_BYTE_YEAR	0
#define S35390A_BYTE_MONTH	1
#define S35390A_BYTE_DAY	2
#define S35390A_BYTE_WDAY	3
#define S35390A_BYTE_HOURS	4
#define S35390A_BYTE_MINS	5
#define S35390A_BYTE_SECS	6

#define S35390A_ALRM_BYTE_WDAY	0
#define S35390A_ALRM_BYTE_HOURS	1
#define S35390A_ALRM_BYTE_MINS	2

/* flags for STATUS1 */
#define S35390A_FLAG_POC	0x01
#define S35390A_FLAG_BLD	0x02
#define S35390A_FLAG_INT2	0x04
#define S35390A_FLAG_24H	0x40
#define S35390A_FLAG_RESET	0x80

/* flag for STATUS2 */
#define S35390A_FLAG_TEST	0x01

#define S35390A_INT2_MODE_MASK		0xF0

#define S35390A_INT2_MODE_NOINTR	0x00
#define S35390A_INT2_MODE_FREQ		0x10
#define S35390A_INT2_MODE_ALARM		0x40
#define S35390A_INT2_MODE_PMIN_EDG	0x20

static const struct i2c_device_id s35390a_id[] = {
	{ "s35390a", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, s35390a_id);

static const struct of_device_id s35390a_of_match[] = {
	{ .compatible = "s35390a" },
	{ .compatible = "sii,s35390a" },
	{ }
};
MODULE_DEVICE_TABLE(of, s35390a_of_match);

struct s35390a {
	struct i2c_client *client[8];
	struct rtc_device *rtc;
	int twentyfourhour;
};

static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
	struct i2c_client *client = s35390a->client[reg];
	struct i2c_msg msg[] = {
		{
			.addr = client->addr,
			.len = len,
			.buf = buf
		},
	};

	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
		return -EIO;

	return 0;
}

static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
	struct i2c_client *client = s35390a->client[reg];
	struct i2c_msg msg[] = {
		{
			.addr = client->addr,
			.flags = I2C_M_RD,
			.len = len,
			.buf = buf
		},
	};

	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
		return -EIO;

	return 0;
}

static int s35390a_init(struct s35390a *s35390a)
{
	u8 buf;
	int ret;
	unsigned initcount = 0;

	/*
	 * At least one of POC and BLD are set, so reinitialise chip. Keeping
	 * this information in the hardware to know later that the time isn't
	 * valid is unfortunately not possible because POC and BLD are cleared
	 * on read. So the reset is best done now.
	 *
	 * The 24H bit is kept over reset, so set it already here.
	 */
initialize:
	buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
	ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);

	if (ret < 0)
		return ret;

	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
	if (ret < 0)
		return ret;

	if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
		/* Try up to five times to reset the chip */
		if (initcount < 5) {
			++initcount;
			goto initialize;
		} else
			return -EIO;
	}

	return 1;
}

/*
 * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
 * To keep the information if an irq is pending, pass the value read from
 * STATUS1 to the caller.
 */
static int s35390a_read_status(struct s35390a *s35390a, char *status1)
{
	int ret;

	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
	if (ret < 0)
		return ret;

	if (*status1 & S35390A_FLAG_POC) {
		/*
		 * Do not communicate for 0.5 seconds since the power-on
		 * detection circuit is in operation.
		 */
		msleep(500);
		return 1;
	} else if (*status1 & S35390A_FLAG_BLD)
		return 1;
	/*
	 * If both POC and BLD are unset everything is fine.
	 */
	return 0;
}

static int s35390a_disable_test_mode(struct s35390a *s35390a)
{
	char buf[1];

	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
		return -EIO;

	if (!(buf[0] & S35390A_FLAG_TEST))
		return 0;

	buf[0] &= ~S35390A_FLAG_TEST;
	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
}

static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
{
	if (s35390a->twentyfourhour)
		return bin2bcd(hour);

	if (hour < 12)
		return bin2bcd(hour);

	return 0x40 | bin2bcd(hour - 12);
}

static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
{
	unsigned hour;

	if (s35390a->twentyfourhour)
		return bcd2bin(reg & 0x3f);

	hour = bcd2bin(reg & 0x3f);
	if (reg & 0x40)
		hour += 12;

	return hour;
}

static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct s35390a	*s35390a = i2c_get_clientdata(client);
	int i, err;
	char buf[7], status;

	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
		"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
		tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
		tm->tm_wday);

	if (s35390a_read_status(s35390a, &status) == 1)
		s35390a_init(s35390a);

	buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
	buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
	buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
	buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
	buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
	buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
	buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);

	/* This chip expects the bits of each byte to be in reverse order */
	for (i = 0; i < 7; ++i)
		buf[i] = bitrev8(buf[i]);

	err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));

	return err;
}

static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct s35390a *s35390a = i2c_get_clientdata(client);
	char buf[7], status;
	int i, err;

	if (s35390a_read_status(s35390a, &status) == 1)
		return -EINVAL;

	err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	if (err < 0)
		return err;

	/* This chip returns the bits of each byte in reverse order */
	for (i = 0; i < 7; ++i)
		buf[i] = bitrev8(buf[i]);

	tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
	tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
	tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
	tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
	tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
	tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
	tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;

	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
		"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
		tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
		tm->tm_wday);

	return 0;
}

static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct s35390a *s35390a = i2c_get_clientdata(client);
	char buf[3], sts = 0;
	int err, i;

	dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
		"mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
		alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
		alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);

	/* disable interrupt (which deasserts the irq line) */
	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	if (err < 0)
		return err;

	/* clear pending interrupt (in STATUS1 only), if any */
	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
	if (err < 0)
		return err;

	if (alm->enabled)
		sts = S35390A_INT2_MODE_ALARM;
	else
		sts = S35390A_INT2_MODE_NOINTR;

	/* This chip expects the bits of each byte to be in reverse order */
	sts = bitrev8(sts);

	/* set interupt mode*/
	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	if (err < 0)
		return err;

	if (alm->time.tm_wday != -1)
		buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
	else
		buf[S35390A_ALRM_BYTE_WDAY] = 0;

	buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
			alm->time.tm_hour) | 0x80;
	buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;

	if (alm->time.tm_hour >= 12)
		buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;

	for (i = 0; i < 3; ++i)
		buf[i] = bitrev8(buf[i]);

	err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
								sizeof(buf));

	return err;
}

static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct s35390a *s35390a = i2c_get_clientdata(client);
	char buf[3], sts;
	int i, err;

	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	if (err < 0)
		return err;

	if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
		/*
		 * When the alarm isn't enabled, the register to configure
		 * the alarm time isn't accessible.
		 */
		alm->enabled = 0;
		return 0;
	} else {
		alm->enabled = 1;
	}

	err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
	if (err < 0)
		return err;

	/* This chip returns the bits of each byte in reverse order */
	for (i = 0; i < 3; ++i)
		buf[i] = bitrev8(buf[i]);

	/*
	 * B0 of the three matching registers is an enable flag. Iff it is set
	 * the configured value is used for matching.
	 */
	if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
		alm->time.tm_wday =
			bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);

	if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
		alm->time.tm_hour =
			s35390a_reg2hr(s35390a,
				       buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);

	if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
		alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);

	/* alarm triggers always at s=0 */
	alm->time.tm_sec = 0;

	dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
			__func__, alm->time.tm_min, alm->time.tm_hour,
			alm->time.tm_wday);

	return 0;
}

static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
			     unsigned long arg)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct s35390a *s35390a = i2c_get_clientdata(client);
	char sts;
	int err;

	switch (cmd) {
	case RTC_VL_READ:
		/* s35390a_reset set lowvoltage flag and init RTC if needed */
		err = s35390a_read_status(s35390a, &sts);
		if (err < 0)
			return err;
		if (copy_to_user((void __user *)arg, &err, sizeof(int)))
			return -EFAULT;
		break;
	case RTC_VL_CLR:
		/* update flag and clear register */
		err = s35390a_init(s35390a);
		if (err < 0)
			return err;
		break;
	default:
		return -ENOIOCTLCMD;
	}

	return 0;
}

static const struct rtc_class_ops s35390a_rtc_ops = {
	.read_time	= s35390a_rtc_read_time,
	.set_time	= s35390a_rtc_set_time,
	.set_alarm	= s35390a_rtc_set_alarm,
	.read_alarm	= s35390a_rtc_read_alarm,
	.ioctl          = s35390a_rtc_ioctl,
};

static struct i2c_driver s35390a_driver;

static int s35390a_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	int err, err_read;
	unsigned int i;
	struct s35390a *s35390a;
	char buf, status1;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		err = -ENODEV;
		goto exit;
	}

	s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
				GFP_KERNEL);
	if (!s35390a) {
		err = -ENOMEM;
		goto exit;
	}

	s35390a->client[0] = client;
	i2c_set_clientdata(client, s35390a);

	/* This chip uses multiple addresses, use dummy devices for them */
	for (i = 1; i < 8; ++i) {
		s35390a->client[i] = i2c_new_dummy(client->adapter,
					client->addr + i);
		if (!s35390a->client[i]) {
			dev_err(&client->dev, "Address %02x unavailable\n",
						client->addr + i);
			err = -EBUSY;
			goto exit_dummy;
		}
	}

	err_read = s35390a_read_status(s35390a, &status1);
	if (err_read < 0) {
		err = err_read;
		dev_err(&client->dev, "error resetting chip\n");
		goto exit_dummy;
	}

	if (status1 & S35390A_FLAG_24H)
		s35390a->twentyfourhour = 1;
	else
		s35390a->twentyfourhour = 0;

	if (status1 & S35390A_FLAG_INT2) {
		/* disable alarm (and maybe test mode) */
		buf = 0;
		err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
		if (err < 0) {
			dev_err(&client->dev, "error disabling alarm");
			goto exit_dummy;
		}
	} else {
		err = s35390a_disable_test_mode(s35390a);
		if (err < 0) {
			dev_err(&client->dev, "error disabling test mode\n");
			goto exit_dummy;
		}
	}

	device_set_wakeup_capable(&client->dev, 1);

	s35390a->rtc = devm_rtc_device_register(&client->dev,
					s35390a_driver.driver.name,
					&s35390a_rtc_ops, THIS_MODULE);

	if (IS_ERR(s35390a->rtc)) {
		err = PTR_ERR(s35390a->rtc);
		goto exit_dummy;
	}

	if (status1 & S35390A_FLAG_INT2)
		rtc_update_irq(s35390a->rtc, 1, RTC_AF);

	return 0;

exit_dummy:
	for (i = 1; i < 8; ++i)
		if (s35390a->client[i])
			i2c_unregister_device(s35390a->client[i]);

exit:
	return err;
}

static int s35390a_remove(struct i2c_client *client)
{
	unsigned int i;
	struct s35390a *s35390a = i2c_get_clientdata(client);

	for (i = 1; i < 8; ++i)
		if (s35390a->client[i])
			i2c_unregister_device(s35390a->client[i]);

	return 0;
}

static struct i2c_driver s35390a_driver = {
	.driver		= {
		.name	= "rtc-s35390a",
		.of_match_table = of_match_ptr(s35390a_of_match),
	},
	.probe		= s35390a_probe,
	.remove		= s35390a_remove,
	.id_table	= s35390a_id,
};

module_i2c_driver(s35390a_driver);

MODULE_AUTHOR("Byron Bradley <[email protected]>");
MODULE_DESCRIPTION("S35390A RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
c46288b0 BB	2	/*
	3	* Seiko Instruments S-35390A RTC Driver
	4	*
	5	* Copyright (c) 2007 Byron Bradley
c46288b0 BB	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/rtc.h>
	10	#include <linux/i2c.h>
	11	#include <linux/bitrev.h>
	12	#include <linux/bcd.h>
	13	#include <linux/slab.h>
8e6583f1	14	#include <linux/delay.h>
c46288b0 BB	15
	16	#define S35390A_CMD_STATUS1 0
	17	#define S35390A_CMD_STATUS2 1
	18	#define S35390A_CMD_TIME1 2
542dd33a ML	19	#define S35390A_CMD_TIME2 3
542dd33a ML	20	#define S35390A_CMD_INT2_REG1 5
c46288b0 BB	21
	22	#define S35390A_BYTE_YEAR 0
	23	#define S35390A_BYTE_MONTH 1
	24	#define S35390A_BYTE_DAY 2
	25	#define S35390A_BYTE_WDAY 3
	26	#define S35390A_BYTE_HOURS 4
	27	#define S35390A_BYTE_MINS 5
	28	#define S35390A_BYTE_SECS 6
	29
542dd33a ML	30	#define S35390A_ALRM_BYTE_WDAY 0
	31	#define S35390A_ALRM_BYTE_HOURS 1
	32	#define S35390A_ALRM_BYTE_MINS 2
	33
3bd32722	34	/* flags for STATUS1 */
c46288b0 BB	35	#define S35390A_FLAG_POC 0x01
c46288b0 BB	36	#define S35390A_FLAG_BLD 0x02
3bd32722	37	#define S35390A_FLAG_INT2 0x04
c46288b0 BB	38	#define S35390A_FLAG_24H 0x40
c46288b0 BB	39	#define S35390A_FLAG_RESET 0x80
3bd32722 UKK	40
3bd32722 UKK	41	/* flag for STATUS2 */
c46288b0 BB	42	#define S35390A_FLAG_TEST 0x01
c46288b0 BB	43
542dd33a ML	44	#define S35390A_INT2_MODE_MASK 0xF0
	45
	46	#define S35390A_INT2_MODE_NOINTR 0x00
	47	#define S35390A_INT2_MODE_FREQ 0x10
	48	#define S35390A_INT2_MODE_ALARM 0x40
	49	#define S35390A_INT2_MODE_PMIN_EDG 0x20
	50
3760f736 JD	51	static const struct i2c_device_id s35390a_id[] = {
	52	{ "s35390a", 0 },
	53	{ }
	54	};
	55	MODULE_DEVICE_TABLE(i2c, s35390a_id);
	56
21f27432 JMC	57	static const struct of_device_id s35390a_of_match[] = {
	58	{ .compatible = "s35390a" },
	59	{ .compatible = "sii,s35390a" },
	60	{ }
	61	};
	62	MODULE_DEVICE_TABLE(of, s35390a_of_match);
	63
c46288b0 BB	64	struct s35390a {
	65	struct i2c_client *client[8];
	66	struct rtc_device *rtc;
	67	int twentyfourhour;
	68	};
	69
	70	static int s35390a_set_reg(struct s35390a s35390a, int reg, char buf, int len)
	71	{
	72	struct i2c_client *client = s35390a->client[reg];
	73	struct i2c_msg msg[] = {
65659f63 S	74	{
	75	.addr = client->addr,
	76	.len = len,
	77	.buf = buf
	78	},
c46288b0 BB	79	};
	80
	81	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
	82	return -EIO;
	83
	84	return 0;
	85	}
	86
	87	static int s35390a_get_reg(struct s35390a s35390a, int reg, char buf, int len)
	88	{
	89	struct i2c_client *client = s35390a->client[reg];
	90	struct i2c_msg msg[] = {
65659f63 S	91	{
	92	.addr = client->addr,
	93	.flags = I2C_M_RD,
	94	.len = len,
	95	.buf = buf
	96	},
c46288b0 BB	97	};
	98
	99	if ((i2c_transfer(client->adapter, msg, 1)) != 1)
	100	return -EIO;
	101
	102	return 0;
	103	}
	104
16486d0c	105	static int s35390a_init(struct s35390a *s35390a)
c46288b0	106	{
ef0f02fd	107	u8 buf;
8e6583f1 UKK	108	int ret;
8e6583f1 UKK	109	unsigned initcount = 0;
c46288b0	110
8e6583f1 UKK	111	/*
	112	* At least one of POC and BLD are set, so reinitialise chip. Keeping
	113	* this information in the hardware to know later that the time isn't
	114	* valid is unfortunately not possible because POC and BLD are cleared
	115	* on read. So the reset is best done now.
	116	*
	117	* The 24H bit is kept over reset, so set it already here.
	118	*/
	119	initialize:
8e6583f1 UKK	120	buf = S35390A_FLAG_RESET \| S35390A_FLAG_24H;
	121	ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
	122
	123	if (ret < 0)
	124	return ret;
	125
	126	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
	127	if (ret < 0)
	128	return ret;
	129
	130	if (buf & (S35390A_FLAG_POC \| S35390A_FLAG_BLD)) {
	131	/* Try up to five times to reset the chip */
	132	if (initcount < 5) {
	133	++initcount;
	134	goto initialize;
	135	} else
	136	return -EIO;
	137	}
	138
	139	return 1;
c46288b0 BB	140	}
c46288b0 BB	141
16486d0c FL	142	/*
	143	* Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
	144	* To keep the information if an irq is pending, pass the value read from
	145	* STATUS1 to the caller.
	146	*/
	147	static int s35390a_read_status(struct s35390a s35390a, char status1)
	148	{
	149	int ret;
	150
	151	ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
	152	if (ret < 0)
	153	return ret;
	154
	155	if (*status1 & S35390A_FLAG_POC) {
	156	/*
	157	* Do not communicate for 0.5 seconds since the power-on
	158	* detection circuit is in operation.
	159	*/
	160	msleep(500);
	161	return 1;
	162	} else if (*status1 & S35390A_FLAG_BLD)
	163	return 1;
	164	/*
	165	* If both POC and BLD are unset everything is fine.
	166	*/
	167	return 0;
	168	}
	169
c46288b0 BB	170	static int s35390a_disable_test_mode(struct s35390a *s35390a)
	171	{
	172	char buf[1];
	173
	174	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
	175	return -EIO;
	176
	177	if (!(buf[0] & S35390A_FLAG_TEST))
	178	return 0;
	179
	180	buf[0] &= ~S35390A_FLAG_TEST;
	181	return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
	182	}
	183
	184	static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
	185	{
	186	if (s35390a->twentyfourhour)
fe20ba70	187	return bin2bcd(hour);
c46288b0 BB	188
c46288b0 BB	189	if (hour < 12)
fe20ba70	190	return bin2bcd(hour);
c46288b0	191
fe20ba70	192	return 0x40 \| bin2bcd(hour - 12);
c46288b0 BB	193	}
	194
	195	static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
	196	{
	197	unsigned hour;
	198
	199	if (s35390a->twentyfourhour)
fe20ba70	200	return bcd2bin(reg & 0x3f);
c46288b0	201
fe20ba70	202	hour = bcd2bin(reg & 0x3f);
c46288b0 BB	203	if (reg & 0x40)
	204	hour += 12;
	205
	206	return hour;
	207	}
	208
779e1aab	209	static int s35390a_rtc_set_time(struct device dev, struct rtc_time tm)
c46288b0	210	{
779e1aab	211	struct i2c_client *client = to_i2c_client(dev);
c46288b0 BB	212	struct s35390a *s35390a = i2c_get_clientdata(client);
c46288b0 BB	213	int i, err;
16486d0c	214	char buf[7], status;
c46288b0 BB	215
	216	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
	217	"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
	218	tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
	219	tm->tm_wday);
	220
16486d0c FL	221	if (s35390a_read_status(s35390a, &status) == 1)
	222	s35390a_init(s35390a);
	223
fe20ba70 AB	224	buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
	225	buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
	226	buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
	227	buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
c46288b0	228	buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
fe20ba70 AB	229	buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
fe20ba70 AB	230	buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
c46288b0 BB	231
	232	/* This chip expects the bits of each byte to be in reverse order */
	233	for (i = 0; i < 7; ++i)
	234	buf[i] = bitrev8(buf[i]);
	235
	236	err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	237
	238	return err;
	239	}
	240
779e1aab	241	static int s35390a_rtc_read_time(struct device dev, struct rtc_time tm)
c46288b0	242	{
779e1aab	243	struct i2c_client *client = to_i2c_client(dev);
c46288b0	244	struct s35390a *s35390a = i2c_get_clientdata(client);
16486d0c	245	char buf[7], status;
c46288b0 BB	246	int i, err;
c46288b0 BB	247
16486d0c FL	248	if (s35390a_read_status(s35390a, &status) == 1)
	249	return -EINVAL;
	250
c46288b0 BB	251	err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
	252	if (err < 0)
	253	return err;
	254
	255	/* This chip returns the bits of each byte in reverse order */
	256	for (i = 0; i < 7; ++i)
	257	buf[i] = bitrev8(buf[i]);
	258
fe20ba70 AB	259	tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
fe20ba70 AB	260	tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
c46288b0	261	tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
fe20ba70 AB	262	tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
	263	tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
	264	tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
	265	tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
c46288b0 BB	266
	267	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
	268	"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
	269	tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
	270	tm->tm_wday);
	271
bb530199	272	return 0;
c46288b0 BB	273	}
c46288b0 BB	274
779e1aab	275	static int s35390a_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
542dd33a	276	{
779e1aab	277	struct i2c_client *client = to_i2c_client(dev);
542dd33a ML	278	struct s35390a *s35390a = i2c_get_clientdata(client);
	279	char buf[3], sts = 0;
	280	int err, i;
	281
	282	dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\
	283	"mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
	284	alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
	285	alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
	286
5227e8a2	287	/* disable interrupt (which deasserts the irq line) */
542dd33a ML	288	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	289	if (err < 0)
	290	return err;
	291
5227e8a2	292	/* clear pending interrupt (in STATUS1 only), if any */
542dd33a ML	293	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
	294	if (err < 0)
	295	return err;
	296
	297	if (alm->enabled)
	298	sts = S35390A_INT2_MODE_ALARM;
	299	else
	300	sts = S35390A_INT2_MODE_NOINTR;
	301
	302	/* This chip expects the bits of each byte to be in reverse order */
	303	sts = bitrev8(sts);
	304
	305	/* set interupt mode*/
	306	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	307	if (err < 0)
	308	return err;
	309
	310	if (alm->time.tm_wday != -1)
	311	buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) \| 0x80;
f87e904d UKK	312	else
f87e904d UKK	313	buf[S35390A_ALRM_BYTE_WDAY] = 0;
542dd33a ML	314
	315	buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
	316	alm->time.tm_hour) \| 0x80;
	317	buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) \| 0x80;
	318
	319	if (alm->time.tm_hour >= 12)
	320	buf[S35390A_ALRM_BYTE_HOURS] \|= 0x40;
	321
	322	for (i = 0; i < 3; ++i)
	323	buf[i] = bitrev8(buf[i]);
	324
	325	err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf,
	326	sizeof(buf));
	327
	328	return err;
	329	}
	330
779e1aab	331	static int s35390a_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
542dd33a	332	{
779e1aab	333	struct i2c_client *client = to_i2c_client(dev);
542dd33a ML	334	struct s35390a *s35390a = i2c_get_clientdata(client);
	335	char buf[3], sts;
	336	int i, err;
	337
	338	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
	339	if (err < 0)
	340	return err;
	341
f87e904d UKK	342	if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
	343	/*
	344	* When the alarm isn't enabled, the register to configure
	345	* the alarm time isn't accessible.
	346	*/
	347	alm->enabled = 0;
	348	return 0;
	349	} else {
	350	alm->enabled = 1;
	351	}
542dd33a ML	352
	353	err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
	354	if (err < 0)
	355	return err;
	356
	357	/* This chip returns the bits of each byte in reverse order */
f87e904d	358	for (i = 0; i < 3; ++i)
542dd33a	359	buf[i] = bitrev8(buf[i]);
542dd33a	360
f87e904d UKK	361	/*
	362	* B0 of the three matching registers is an enable flag. Iff it is set
	363	* the configured value is used for matching.
	364	*/
	365	if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
	366	alm->time.tm_wday =
	367	bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
	368
	369	if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
	370	alm->time.tm_hour =
	371	s35390a_reg2hr(s35390a,
	372	buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
	373
	374	if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
	375	alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
	376
	377	/* alarm triggers always at s=0 */
	378	alm->time.tm_sec = 0;
542dd33a ML	379
	380	dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
	381	__func__, alm->time.tm_min, alm->time.tm_hour,
	382	alm->time.tm_wday);
	383
	384	return 0;
	385	}
	386
7a1fe407 FL	387	static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
	388	unsigned long arg)
	389	{
	390	struct i2c_client *client = to_i2c_client(dev);
	391	struct s35390a *s35390a = i2c_get_clientdata(client);
	392	char sts;
	393	int err;
	394
	395	switch (cmd) {
	396	case RTC_VL_READ:
	397	/* s35390a_reset set lowvoltage flag and init RTC if needed */
	398	err = s35390a_read_status(s35390a, &sts);
	399	if (err < 0)
	400	return err;
	401	if (copy_to_user((void __user *)arg, &err, sizeof(int)))
	402	return -EFAULT;
	403	break;
	404	case RTC_VL_CLR:
	405	/* update flag and clear register */
	406	err = s35390a_init(s35390a);
	407	if (err < 0)
	408	return err;
	409	break;
	410	default:
	411	return -ENOIOCTLCMD;
	412	}
	413
	414	return 0;
	415	}
	416
c46288b0 BB	417	static const struct rtc_class_ops s35390a_rtc_ops = {
	418	.read_time = s35390a_rtc_read_time,
	419	.set_time = s35390a_rtc_set_time,
542dd33a ML	420	.set_alarm = s35390a_rtc_set_alarm,
542dd33a ML	421	.read_alarm = s35390a_rtc_read_alarm,
7a1fe407	422	.ioctl = s35390a_rtc_ioctl,
c46288b0 BB	423	};
	424
	425	static struct i2c_driver s35390a_driver;
	426
d2653e92 JD	427	static int s35390a_probe(struct i2c_client *client,
d2653e92 JD	428	const struct i2c_device_id *id)
c46288b0	429	{
16486d0c	430	int err, err_read;
c46288b0 BB	431	unsigned int i;
c46288b0 BB	432	struct s35390a *s35390a;
3bd32722	433	char buf, status1;
c46288b0 BB	434
	435	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	436	err = -ENODEV;
	437	goto exit;
	438	}
	439
b4cd3d6a JH	440	s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
b4cd3d6a JH	441	GFP_KERNEL);
c46288b0 BB	442	if (!s35390a) {
	443	err = -ENOMEM;
	444	goto exit;
	445	}
	446
	447	s35390a->client[0] = client;
	448	i2c_set_clientdata(client, s35390a);
	449
	450	/* This chip uses multiple addresses, use dummy devices for them */
	451	for (i = 1; i < 8; ++i) {
	452	s35390a->client[i] = i2c_new_dummy(client->adapter,
60b129d7	453	client->addr + i);
c46288b0 BB	454	if (!s35390a->client[i]) {
	455	dev_err(&client->dev, "Address %02x unavailable\n",
	456	client->addr + i);
	457	err = -EBUSY;
	458	goto exit_dummy;
	459	}
	460	}
	461
16486d0c FL	462	err_read = s35390a_read_status(s35390a, &status1);
	463	if (err_read < 0) {
	464	err = err_read;
c46288b0 BB	465	dev_err(&client->dev, "error resetting chip\n");
	466	goto exit_dummy;
	467	}
	468
3bd32722	469	if (status1 & S35390A_FLAG_24H)
c46288b0 BB	470	s35390a->twentyfourhour = 1;
	471	else
	472	s35390a->twentyfourhour = 0;
	473
3bd32722 UKK	474	if (status1 & S35390A_FLAG_INT2) {
	475	/* disable alarm (and maybe test mode) */
	476	buf = 0;
	477	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
	478	if (err < 0) {
	479	dev_err(&client->dev, "error disabling alarm");
	480	goto exit_dummy;
	481	}
	482	} else {
	483	err = s35390a_disable_test_mode(s35390a);
	484	if (err < 0) {
	485	dev_err(&client->dev, "error disabling test mode\n");
	486	goto exit_dummy;
	487	}
	488	}
	489
542dd33a ML	490	device_set_wakeup_capable(&client->dev, 1);
542dd33a ML	491
b4cd3d6a JH	492	s35390a->rtc = devm_rtc_device_register(&client->dev,
	493	s35390a_driver.driver.name,
	494	&s35390a_rtc_ops, THIS_MODULE);
c46288b0 BB	495
	496	if (IS_ERR(s35390a->rtc)) {
	497	err = PTR_ERR(s35390a->rtc);
	498	goto exit_dummy;
	499	}
3bd32722 UKK	500
	501	if (status1 & S35390A_FLAG_INT2)
	502	rtc_update_irq(s35390a->rtc, 1, RTC_AF);
	503
c46288b0 BB	504	return 0;
	505
	506	exit_dummy:
	507	for (i = 1; i < 8; ++i)
	508	if (s35390a->client[i])
	509	i2c_unregister_device(s35390a->client[i]);
c46288b0 BB	510
	511	exit:
	512	return err;
	513	}
	514
	515	static int s35390a_remove(struct i2c_client *client)
	516	{
	517	unsigned int i;
c46288b0	518	struct s35390a *s35390a = i2c_get_clientdata(client);
b4cd3d6a	519
c46288b0 BB	520	for (i = 1; i < 8; ++i)
	521	if (s35390a->client[i])
	522	i2c_unregister_device(s35390a->client[i]);
	523
c46288b0 BB	524	return 0;
	525	}
	526
	527	static struct i2c_driver s35390a_driver = {
	528	.driver = {
	529	.name = "rtc-s35390a",
21f27432	530	.of_match_table = of_match_ptr(s35390a_of_match),
c46288b0 BB	531	},
	532	.probe = s35390a_probe,
	533	.remove = s35390a_remove,
3760f736	534	.id_table = s35390a_id,
c46288b0 BB	535	};
c46288b0 BB	536
0abc9201	537	module_i2c_driver(s35390a_driver);
c46288b0 BB	538
	539	MODULE_AUTHOR("Byron Bradley <[email protected]>");
	540	MODULE_DESCRIPTION("S35390A RTC driver");
	541	MODULE_LICENSE("GPL");