[linux-2.6-block.git] / drivers / rtc / rtc-rx6110.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for the Epson RTC module RX-6110 SA
 *
 * Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
 * Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>

/* RX-6110 Register definitions */
#define RX6110_REG_SEC		0x10
#define RX6110_REG_MIN		0x11
#define RX6110_REG_HOUR		0x12
#define RX6110_REG_WDAY		0x13
#define RX6110_REG_MDAY		0x14
#define RX6110_REG_MONTH	0x15
#define RX6110_REG_YEAR		0x16
#define RX6110_REG_RES1		0x17
#define RX6110_REG_ALMIN	0x18
#define RX6110_REG_ALHOUR	0x19
#define RX6110_REG_ALWDAY	0x1A
#define RX6110_REG_TCOUNT0	0x1B
#define RX6110_REG_TCOUNT1	0x1C
#define RX6110_REG_EXT		0x1D
#define RX6110_REG_FLAG		0x1E
#define RX6110_REG_CTRL		0x1F
#define RX6110_REG_USER0	0x20
#define RX6110_REG_USER1	0x21
#define RX6110_REG_USER2	0x22
#define RX6110_REG_USER3	0x23
#define RX6110_REG_USER4	0x24
#define RX6110_REG_USER5	0x25
#define RX6110_REG_USER6	0x26
#define RX6110_REG_USER7	0x27
#define RX6110_REG_USER8	0x28
#define RX6110_REG_USER9	0x29
#define RX6110_REG_USERA	0x2A
#define RX6110_REG_USERB	0x2B
#define RX6110_REG_USERC	0x2C
#define RX6110_REG_USERD	0x2D
#define RX6110_REG_USERE	0x2E
#define RX6110_REG_USERF	0x2F
#define RX6110_REG_RES2		0x30
#define RX6110_REG_RES3		0x31
#define RX6110_REG_IRQ		0x32

#define RX6110_BIT_ALARM_EN		BIT(7)

/* Extension Register (1Dh) bit positions */
#define RX6110_BIT_EXT_TSEL0		BIT(0)
#define RX6110_BIT_EXT_TSEL1		BIT(1)
#define RX6110_BIT_EXT_TSEL2		BIT(2)
#define RX6110_BIT_EXT_WADA		BIT(3)
#define RX6110_BIT_EXT_TE		BIT(4)
#define RX6110_BIT_EXT_USEL		BIT(5)
#define RX6110_BIT_EXT_FSEL0		BIT(6)
#define RX6110_BIT_EXT_FSEL1		BIT(7)

/* Flag Register (1Eh) bit positions */
#define RX6110_BIT_FLAG_VLF		BIT(1)
#define RX6110_BIT_FLAG_AF		BIT(3)
#define RX6110_BIT_FLAG_TF		BIT(4)
#define RX6110_BIT_FLAG_UF		BIT(5)

/* Control Register (1Fh) bit positions */
#define RX6110_BIT_CTRL_TBKE		BIT(0)
#define RX6110_BIT_CTRL_TBKON		BIT(1)
#define RX6110_BIT_CTRL_TSTP		BIT(2)
#define RX6110_BIT_CTRL_AIE		BIT(3)
#define RX6110_BIT_CTRL_TIE		BIT(4)
#define RX6110_BIT_CTRL_UIE		BIT(5)
#define RX6110_BIT_CTRL_STOP		BIT(6)
#define RX6110_BIT_CTRL_TEST		BIT(7)

enum {
	RTC_SEC = 0,
	RTC_MIN,
	RTC_HOUR,
	RTC_WDAY,
	RTC_MDAY,
	RTC_MONTH,
	RTC_YEAR,
	RTC_NR_TIME
};

#define RX6110_DRIVER_NAME		"rx6110"

struct rx6110_data {
	struct rtc_device *rtc;
	struct regmap *regmap;
};

/**
 * rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
 *
 * @tm: holds date and time
 * @data: holds the encoding in rx6110 native form
 */
static int rx6110_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
{
	pr_debug("%s: date %ptRr\n", __func__, tm);

	/*
	 * The year in the RTC is a value between 0 and 99.
	 * Assume that this represents the current century
	 * and disregard all other values.
	 */
	if (tm->tm_year < 100 || tm->tm_year >= 200)
		return -EINVAL;

	data[RTC_SEC] = bin2bcd(tm->tm_sec);
	data[RTC_MIN] = bin2bcd(tm->tm_min);
	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));
	data[RTC_MDAY] = bin2bcd(tm->tm_mday);
	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);

	return 0;
}

/**
 * rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
 *
 * @data: holds the encoding in rx6110 native form
 * @tm: holds date and time
 */
static int rx6110_data_to_rtc_tm(u8 *data, struct rtc_time *tm)
{
	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);
	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);
	/* only 24-hour clock */
	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);
	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);
	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;

	pr_debug("%s: date %ptRr\n", __func__, tm);

	/*
	 * The year in the RTC is a value between 0 and 99.
	 * Assume that this represents the current century
	 * and disregard all other values.
	 */
	if (tm->tm_year < 100 || tm->tm_year >= 200)
		return -EINVAL;

	return 0;
}

/**
 * rx6110_set_time - set the current time in the rx6110 registers
 *
 * @dev: the rtc device in use
 * @tm: holds date and time
 *
 * BUG: The HW assumes every year that is a multiple of 4 to be a leap
 * year. Next time this is wrong is 2100, which will not be a leap year
 *
 * Note: If STOP is not set/cleared, the clock will start when the seconds
 *       register is written
 *
 */
static int rx6110_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	int ret;

	ret = rx6110_rtc_tm_to_data(tm, data);
	if (ret < 0)
		return ret;

	/* set STOP bit before changing clock/calendar */
	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
				 RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP);
	if (ret)
		return ret;

	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,
				RTC_NR_TIME);
	if (ret)
		return ret;

	/* The time in the RTC is valid. Be sure to have VLF cleared. */
	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
				 RX6110_BIT_FLAG_VLF, 0);
	if (ret)
		return ret;

	/* clear STOP bit after changing clock/calendar */
	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
				 RX6110_BIT_CTRL_STOP, 0);

	return ret;
}

/**
 * rx6110_get_time - get the current time from the rx6110 registers
 * @dev: the rtc device in use
 * @tm: holds date and time
 */
static int rx6110_get_time(struct device *dev, struct rtc_time *tm)
{
	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
	u8 data[RTC_NR_TIME];
	int flags;
	int ret;

	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
	if (ret)
		return -EINVAL;

	/* check for VLF Flag (set at power-on) */
	if ((flags & RX6110_BIT_FLAG_VLF)) {
		dev_warn(dev, "Voltage low, data is invalid.\n");
		return -EINVAL;
	}

	/* read registers to date */
	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,
			       RTC_NR_TIME);
	if (ret)
		return ret;

	ret = rx6110_data_to_rtc_tm(data, tm);
	if (ret)
		return ret;

	dev_dbg(dev, "%s: date %ptRr\n", __func__, tm);

	return 0;
}

static const struct reg_sequence rx6110_default_regs[] = {
	{ RX6110_REG_RES1,   0xB8 },
	{ RX6110_REG_RES2,   0x00 },
	{ RX6110_REG_RES3,   0x10 },
	{ RX6110_REG_IRQ,    0x00 },
	{ RX6110_REG_ALMIN,  0x00 },
	{ RX6110_REG_ALHOUR, 0x00 },
	{ RX6110_REG_ALWDAY, 0x00 },
};

/**
 * rx6110_init - initialize the rx6110 registers
 *
 * @rx6110: pointer to the rx6110 struct in use
 *
 */
static int rx6110_init(struct rx6110_data *rx6110)
{
	struct rtc_device *rtc = rx6110->rtc;
	int flags;
	int ret;

	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,
				 RX6110_BIT_EXT_TE, 0);
	if (ret)
		return ret;

	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,
				    ARRAY_SIZE(rx6110_default_regs));
	if (ret)
		return ret;

	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
	if (ret)
		return ret;

	/* check for VLF Flag (set at power-on) */
	if ((flags & RX6110_BIT_FLAG_VLF))
		dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");

	/* check for Alarm Flag */
	if (flags & RX6110_BIT_FLAG_AF)
		dev_warn(&rtc->dev, "An alarm may have been missed.\n");

	/* check for Periodic Timer Flag */
	if (flags & RX6110_BIT_FLAG_TF)
		dev_warn(&rtc->dev, "Periodic timer was detected\n");

	/* check for Update Timer Flag */
	if (flags & RX6110_BIT_FLAG_UF)
		dev_warn(&rtc->dev, "Update timer was detected\n");

	/* clear all flags BUT VLF */
	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
				 RX6110_BIT_FLAG_AF |
				 RX6110_BIT_FLAG_UF |
				 RX6110_BIT_FLAG_TF,
				 0);

	return ret;
}

static const struct rtc_class_ops rx6110_rtc_ops = {
	.read_time = rx6110_get_time,
	.set_time = rx6110_set_time,
};

static int rx6110_probe(struct rx6110_data *rx6110, struct device *dev)
{
	int err;

	rx6110->rtc = devm_rtc_device_register(dev,
					       RX6110_DRIVER_NAME,
					       &rx6110_rtc_ops, THIS_MODULE);

	if (IS_ERR(rx6110->rtc))
		return PTR_ERR(rx6110->rtc);

	err = rx6110_init(rx6110);
	if (err)
		return err;

	rx6110->rtc->max_user_freq = 1;

	return 0;
}

#if IS_ENABLED(CONFIG_SPI_MASTER)
static struct regmap_config regmap_spi_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = RX6110_REG_IRQ,
	.read_flag_mask = 0x80,
};

/**
 * rx6110_spi_probe - initialize rtc driver
 * @spi: pointer to spi device
 */
static int rx6110_spi_probe(struct spi_device *spi)
{
	struct rx6110_data *rx6110;

	if ((spi->bits_per_word && spi->bits_per_word != 8) ||
	    (spi->max_speed_hz > 2000000) ||
	    (spi->mode != (SPI_CS_HIGH | SPI_CPOL | SPI_CPHA))) {
		dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",
			 spi->bits_per_word, spi->max_speed_hz, spi->mode);
		dev_warn(&spi->dev, "driving device in an unsupported mode");
	}

	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);
	if (!rx6110)
		return -ENOMEM;

	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);
	if (IS_ERR(rx6110->regmap)) {
		dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");
		return PTR_ERR(rx6110->regmap);
	}

	spi_set_drvdata(spi, rx6110);

	return rx6110_probe(rx6110, &spi->dev);
}

static const struct spi_device_id rx6110_spi_id[] = {
	{ "rx6110", 0 },
	{ }
};
MODULE_DEVICE_TABLE(spi, rx6110_spi_id);

static const __maybe_unused struct of_device_id rx6110_spi_of_match[] = {
	{ .compatible = "epson,rx6110" },
	{ },
};
MODULE_DEVICE_TABLE(of, rx6110_spi_of_match);

static struct spi_driver rx6110_spi_driver = {
	.driver = {
		.name = RX6110_DRIVER_NAME,
		.of_match_table = of_match_ptr(rx6110_spi_of_match),
	},
	.probe		= rx6110_spi_probe,
	.id_table	= rx6110_spi_id,
};

static int rx6110_spi_register(void)
{
	return spi_register_driver(&rx6110_spi_driver);
}

static void rx6110_spi_unregister(void)
{
	spi_unregister_driver(&rx6110_spi_driver);
}
#else
static int rx6110_spi_register(void)
{
	return 0;
}

static void rx6110_spi_unregister(void)
{
}
#endif /* CONFIG_SPI_MASTER */

#if IS_ENABLED(CONFIG_I2C)
static struct regmap_config regmap_i2c_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = RX6110_REG_IRQ,
	.read_flag_mask = 0x80,
};

static int rx6110_i2c_probe(struct i2c_client *client)
{
	struct i2c_adapter *adapter = client->adapter;
	struct rx6110_data *rx6110;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
				| I2C_FUNC_SMBUS_I2C_BLOCK)) {
		dev_err(&adapter->dev,
			"doesn't support required functionality\n");
		return -EIO;
	}

	rx6110 = devm_kzalloc(&client->dev, sizeof(*rx6110), GFP_KERNEL);
	if (!rx6110)
		return -ENOMEM;

	rx6110->regmap = devm_regmap_init_i2c(client, &regmap_i2c_config);
	if (IS_ERR(rx6110->regmap)) {
		dev_err(&client->dev, "regmap init failed for rtc rx6110\n");
		return PTR_ERR(rx6110->regmap);
	}

	i2c_set_clientdata(client, rx6110);

	return rx6110_probe(rx6110, &client->dev);
}

static const struct acpi_device_id rx6110_i2c_acpi_match[] = {
	{ "SECC6110" },
	{ }
};
MODULE_DEVICE_TABLE(acpi, rx6110_i2c_acpi_match);

static const struct i2c_device_id rx6110_i2c_id[] = {
	{ "rx6110", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rx6110_i2c_id);

static struct i2c_driver rx6110_i2c_driver = {
	.driver = {
		.name = RX6110_DRIVER_NAME,
		.acpi_match_table = rx6110_i2c_acpi_match,
	},
	.probe_new	= rx6110_i2c_probe,
	.id_table	= rx6110_i2c_id,
};

static int rx6110_i2c_register(void)
{
	return i2c_add_driver(&rx6110_i2c_driver);
}

static void rx6110_i2c_unregister(void)
{
	i2c_del_driver(&rx6110_i2c_driver);
}
#else
static int rx6110_i2c_register(void)
{
	return 0;
}

static void rx6110_i2c_unregister(void)
{
}
#endif /* CONFIG_I2C */

static int __init rx6110_module_init(void)
{
	int ret;

	ret = rx6110_spi_register();
	if (ret)
		return ret;

	ret = rx6110_i2c_register();
	if (ret)
		rx6110_spi_unregister();

	return ret;
}
module_init(rx6110_module_init);

static void __exit rx6110_module_exit(void)
{
	rx6110_spi_unregister();
	rx6110_i2c_unregister();
}
module_exit(rx6110_module_exit);

MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
MODULE_DESCRIPTION("RX-6110 SA RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
6d2130e6	1	// SPDX-License-Identifier: GPL-2.0-only
68298c2d ST	2	/*
	3	* Driver for the Epson RTC module RX-6110 SA
	4	*
	5	* Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
	6	* Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
68298c2d ST	7	*/
	8
	9	#include <linux/bcd.h>
	10	#include <linux/init.h>
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
68298c2d ST	13	#include <linux/regmap.h>
68298c2d ST	14	#include <linux/rtc.h>
f9bf089a DG	15	#include <linux/of.h>
f9bf089a DG	16	#include <linux/of_device.h>
68298c2d	17	#include <linux/spi/spi.h>
afa819c2	18	#include <linux/i2c.h>
68298c2d ST	19
	20	/* RX-6110 Register definitions */
	21	#define RX6110_REG_SEC 0x10
	22	#define RX6110_REG_MIN 0x11
	23	#define RX6110_REG_HOUR 0x12
	24	#define RX6110_REG_WDAY 0x13
	25	#define RX6110_REG_MDAY 0x14
	26	#define RX6110_REG_MONTH 0x15
	27	#define RX6110_REG_YEAR 0x16
	28	#define RX6110_REG_RES1 0x17
	29	#define RX6110_REG_ALMIN 0x18
	30	#define RX6110_REG_ALHOUR 0x19
	31	#define RX6110_REG_ALWDAY 0x1A
	32	#define RX6110_REG_TCOUNT0 0x1B
	33	#define RX6110_REG_TCOUNT1 0x1C
	34	#define RX6110_REG_EXT 0x1D
	35	#define RX6110_REG_FLAG 0x1E
	36	#define RX6110_REG_CTRL 0x1F
	37	#define RX6110_REG_USER0 0x20
	38	#define RX6110_REG_USER1 0x21
	39	#define RX6110_REG_USER2 0x22
	40	#define RX6110_REG_USER3 0x23
	41	#define RX6110_REG_USER4 0x24
	42	#define RX6110_REG_USER5 0x25
	43	#define RX6110_REG_USER6 0x26
	44	#define RX6110_REG_USER7 0x27
	45	#define RX6110_REG_USER8 0x28
	46	#define RX6110_REG_USER9 0x29
	47	#define RX6110_REG_USERA 0x2A
	48	#define RX6110_REG_USERB 0x2B
	49	#define RX6110_REG_USERC 0x2C
	50	#define RX6110_REG_USERD 0x2D
	51	#define RX6110_REG_USERE 0x2E
	52	#define RX6110_REG_USERF 0x2F
	53	#define RX6110_REG_RES2 0x30
	54	#define RX6110_REG_RES3 0x31
	55	#define RX6110_REG_IRQ 0x32
	56
	57	#define RX6110_BIT_ALARM_EN BIT(7)
	58
	59	/* Extension Register (1Dh) bit positions */
	60	#define RX6110_BIT_EXT_TSEL0 BIT(0)
	61	#define RX6110_BIT_EXT_TSEL1 BIT(1)
	62	#define RX6110_BIT_EXT_TSEL2 BIT(2)
	63	#define RX6110_BIT_EXT_WADA BIT(3)
	64	#define RX6110_BIT_EXT_TE BIT(4)
	65	#define RX6110_BIT_EXT_USEL BIT(5)
	66	#define RX6110_BIT_EXT_FSEL0 BIT(6)
	67	#define RX6110_BIT_EXT_FSEL1 BIT(7)
	68
	69	/* Flag Register (1Eh) bit positions */
	70	#define RX6110_BIT_FLAG_VLF BIT(1)
	71	#define RX6110_BIT_FLAG_AF BIT(3)
	72	#define RX6110_BIT_FLAG_TF BIT(4)
	73	#define RX6110_BIT_FLAG_UF BIT(5)
	74
	75	/* Control Register (1Fh) bit positions */
	76	#define RX6110_BIT_CTRL_TBKE BIT(0)
	77	#define RX6110_BIT_CTRL_TBKON BIT(1)
	78	#define RX6110_BIT_CTRL_TSTP BIT(2)
	79	#define RX6110_BIT_CTRL_AIE BIT(3)
	80	#define RX6110_BIT_CTRL_TIE BIT(4)
	81	#define RX6110_BIT_CTRL_UIE BIT(5)
	82	#define RX6110_BIT_CTRL_STOP BIT(6)
83	#define RX6110_BIT_CTRL_TEST BIT(7)
84
85	enum {
86	RTC_SEC = 0,
87	RTC_MIN,
88	RTC_HOUR,
89	RTC_WDAY,
90	RTC_MDAY,
91	RTC_MONTH,
92	RTC_YEAR,
93	RTC_NR_TIME
94	};
95
96	#define RX6110_DRIVER_NAME "rx6110"
97
98	struct rx6110_data {
99	struct rtc_device *rtc;
100	struct regmap *regmap;
101	};
102
103	/**
104	* rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
105	*
106	* @tm: holds date and time
107	* @data: holds the encoding in rx6110 native form
108	*/
109	static int rx6110_rtc_tm_to_data(struct rtc_time tm, u8 data)
110	{
a3f60bb3	111	pr_debug("%s: date %ptRr\n", __func__, tm);
68298c2d ST	112
	113	/*
	114	* The year in the RTC is a value between 0 and 99.
	115	* Assume that this represents the current century
	116	* and disregard all other values.
	117	*/
	118	if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
	119	return -EINVAL;
	120
	121	data[RTC_SEC] = bin2bcd(tm->tm_sec);
	122	data[RTC_MIN] = bin2bcd(tm->tm_min);
	123	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
	124	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));
	125	data[RTC_MDAY] = bin2bcd(tm->tm_mday);
	126	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
	127	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);
	128
	129	return 0;
	130	}
	131
	132	/**
	133	* rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
	134	*
	135	* @data: holds the encoding in rx6110 native form
	136	* @tm: holds date and time
	137	*/
	138	static int rx6110_data_to_rtc_tm(u8 data, struct rtc_time tm)
	139	{
	140	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);
	141	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);
	142	/* only 24-hour clock */
	143	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
	144	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);
	145	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);
	146	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
	147	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;
	148
a3f60bb3	149	pr_debug("%s: date %ptRr\n", __func__, tm);
68298c2d ST	150
	151	/*
	152	* The year in the RTC is a value between 0 and 99.
	153	* Assume that this represents the current century
	154	* and disregard all other values.
	155	*/
	156	if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
	157	return -EINVAL;
	158
	159	return 0;
	160	}
	161
	162	/**
	163	* rx6110_set_time - set the current time in the rx6110 registers
	164	*
	165	* @dev: the rtc device in use
	166	* @tm: holds date and time
	167	*
	168	* BUG: The HW assumes every year that is a multiple of 4 to be a leap
	169	* year. Next time this is wrong is 2100, which will not be a leap year
	170	*
	171	* Note: If STOP is not set/cleared, the clock will start when the seconds
	172	* register is written
	173	*
	174	*/
	175	static int rx6110_set_time(struct device dev, struct rtc_time tm)
	176	{
	177	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
	178	u8 data[RTC_NR_TIME];
	179	int ret;
	180
	181	ret = rx6110_rtc_tm_to_data(tm, data);
	182	if (ret < 0)
	183	return ret;
	184
	185	/* set STOP bit before changing clock/calendar */
	186	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
	187	RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP);
	188	if (ret)
	189	return ret;
	190
	191	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,
	192	RTC_NR_TIME);
	193	if (ret)
	194	return ret;
	195
	196	/* The time in the RTC is valid. Be sure to have VLF cleared. */
	197	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
	198	RX6110_BIT_FLAG_VLF, 0);
	199	if (ret)
	200	return ret;
	201
	202	/* clear STOP bit after changing clock/calendar */
	203	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
	204	RX6110_BIT_CTRL_STOP, 0);
	205
	206	return ret;
	207	}
	208
	209	/**
	210	* rx6110_get_time - get the current time from the rx6110 registers
	211	* @dev: the rtc device in use
	212	* @tm: holds date and time
	213	*/
214	static int rx6110_get_time(struct device dev, struct rtc_time tm)
215	{
216	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
217	u8 data[RTC_NR_TIME];
218	int flags;
219	int ret;
220
221	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
222	if (ret)
223	return -EINVAL;
224
225	/* check for VLF Flag (set at power-on) */
226	if ((flags & RX6110_BIT_FLAG_VLF)) {
227	dev_warn(dev, "Voltage low, data is invalid.\n");
228	return -EINVAL;
229	}
230
231	/* read registers to date */
232	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,
233	RTC_NR_TIME);
234	if (ret)
235	return ret;
236
237	ret = rx6110_data_to_rtc_tm(data, tm);
238	if (ret)
239	return ret;
240
a3f60bb3	241	dev_dbg(dev, "%s: date %ptRr\n", __func__, tm);
68298c2d	242
22652ba7	243	return 0;
68298c2d ST	244	}
	245
	246	static const struct reg_sequence rx6110_default_regs[] = {
	247	{ RX6110_REG_RES1, 0xB8 },
	248	{ RX6110_REG_RES2, 0x00 },
	249	{ RX6110_REG_RES3, 0x10 },
	250	{ RX6110_REG_IRQ, 0x00 },
	251	{ RX6110_REG_ALMIN, 0x00 },
	252	{ RX6110_REG_ALHOUR, 0x00 },
	253	{ RX6110_REG_ALWDAY, 0x00 },
	254	};
	255
	256	/**
	257	* rx6110_init - initialize the rx6110 registers
	258	*
	259	* @rx6110: pointer to the rx6110 struct in use
	260	*
	261	*/
	262	static int rx6110_init(struct rx6110_data *rx6110)
	263	{
	264	struct rtc_device *rtc = rx6110->rtc;
	265	int flags;
	266	int ret;
	267
	268	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,
	269	RX6110_BIT_EXT_TE, 0);
	270	if (ret)
	271	return ret;
	272
	273	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,
	274	ARRAY_SIZE(rx6110_default_regs));
	275	if (ret)
	276	return ret;
	277
	278	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
	279	if (ret)
	280	return ret;
	281
	282	/* check for VLF Flag (set at power-on) */
	283	if ((flags & RX6110_BIT_FLAG_VLF))
	284	dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");
	285
	286	/* check for Alarm Flag */
	287	if (flags & RX6110_BIT_FLAG_AF)
	288	dev_warn(&rtc->dev, "An alarm may have been missed.\n");
	289
	290	/* check for Periodic Timer Flag */
	291	if (flags & RX6110_BIT_FLAG_TF)
	292	dev_warn(&rtc->dev, "Periodic timer was detected\n");
	293
	294	/* check for Update Timer Flag */
	295	if (flags & RX6110_BIT_FLAG_UF)
	296	dev_warn(&rtc->dev, "Update timer was detected\n");
	297
	298	/* clear all flags BUT VLF */
	299	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
	300	RX6110_BIT_FLAG_AF \|
	301	RX6110_BIT_FLAG_UF \|
	302	RX6110_BIT_FLAG_TF,
	303	0);
	304
	305	return ret;
	306	}
	307
34c7b3ac	308	static const struct rtc_class_ops rx6110_rtc_ops = {
68298c2d ST	309	.read_time = rx6110_get_time,
	310	.set_time = rx6110_set_time,
	311	};
	312
afa819c2 CH	313	static int rx6110_probe(struct rx6110_data rx6110, struct device dev)
	314	{
	315	int err;
	316
	317	rx6110->rtc = devm_rtc_device_register(dev,
	318	RX6110_DRIVER_NAME,
	319	&rx6110_rtc_ops, THIS_MODULE);
	320
	321	if (IS_ERR(rx6110->rtc))
	322	return PTR_ERR(rx6110->rtc);
	323
	324	err = rx6110_init(rx6110);
	325	if (err)
	326	return err;
	327
	328	rx6110->rtc->max_user_freq = 1;
	329
	330	return 0;
	331	}
	332
def8550f	333	#if IS_ENABLED(CONFIG_SPI_MASTER)
68298c2d ST	334	static struct regmap_config regmap_spi_config = {
	335	.reg_bits = 8,
	336	.val_bits = 8,
	337	.max_register = RX6110_REG_IRQ,
	338	.read_flag_mask = 0x80,
	339	};
	340
	341	/**
afa819c2	342	* rx6110_spi_probe - initialize rtc driver
68298c2d ST	343	* @spi: pointer to spi device
68298c2d ST	344	*/
afa819c2	345	static int rx6110_spi_probe(struct spi_device *spi)
68298c2d ST	346	{
68298c2d ST	347	struct rx6110_data *rx6110;
68298c2d ST	348
	349	if ((spi->bits_per_word && spi->bits_per_word != 8) \|\|
	350	(spi->max_speed_hz > 2000000) \|\|
	351	(spi->mode != (SPI_CS_HIGH \| SPI_CPOL \| SPI_CPHA))) {
	352	dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",
	353	spi->bits_per_word, spi->max_speed_hz, spi->mode);
	354	dev_warn(&spi->dev, "driving device in an unsupported mode");
	355	}
	356
	357	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);
	358	if (!rx6110)
	359	return -ENOMEM;
	360
	361	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);
	362	if (IS_ERR(rx6110->regmap)) {
	363	dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");
	364	return PTR_ERR(rx6110->regmap);
	365	}
	366
	367	spi_set_drvdata(spi, rx6110);
	368
afa819c2	369	return rx6110_probe(rx6110, &spi->dev);
68298c2d ST	370	}
68298c2d ST	371
afa819c2	372	static const struct spi_device_id rx6110_spi_id[] = {
68298c2d ST	373	{ "rx6110", 0 },
	374	{ }
	375	};
afa819c2	376	MODULE_DEVICE_TABLE(spi, rx6110_spi_id);
68298c2d	377
103c14db	378	static const __maybe_unused struct of_device_id rx6110_spi_of_match[] = {
f9bf089a DG	379	{ .compatible = "epson,rx6110" },
	380	{ },
	381	};
	382	MODULE_DEVICE_TABLE(of, rx6110_spi_of_match);
	383
afa819c2	384	static struct spi_driver rx6110_spi_driver = {
68298c2d ST	385	.driver = {
68298c2d ST	386	.name = RX6110_DRIVER_NAME,
f9bf089a	387	.of_match_table = of_match_ptr(rx6110_spi_of_match),
68298c2d	388	},
afa819c2 CH	389	.probe = rx6110_spi_probe,
	390	.id_table = rx6110_spi_id,
	391	};
	392
	393	static int rx6110_spi_register(void)
	394	{
	395	return spi_register_driver(&rx6110_spi_driver);
	396	}
	397
	398	static void rx6110_spi_unregister(void)
	399	{
	400	spi_unregister_driver(&rx6110_spi_driver);
	401	}
	402	#else
	403	static int rx6110_spi_register(void)
	404	{
	405	return 0;
	406	}
	407
	408	static void rx6110_spi_unregister(void)
	409	{
	410	}
	411	#endif /* CONFIG_SPI_MASTER */
	412
def8550f	413	#if IS_ENABLED(CONFIG_I2C)
afa819c2 CH	414	static struct regmap_config regmap_i2c_config = {
	415	.reg_bits = 8,
	416	.val_bits = 8,
	417	.max_register = RX6110_REG_IRQ,
	418	.read_flag_mask = 0x80,
68298c2d ST	419	};
68298c2d ST	420
3f4a3322	421	static int rx6110_i2c_probe(struct i2c_client *client)
afa819c2	422	{
38b17bc9	423	struct i2c_adapter *adapter = client->adapter;
afa819c2 CH	424	struct rx6110_data *rx6110;
	425
	426	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	427	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	428	dev_err(&adapter->dev,
	429	"doesn't support required functionality\n");
	430	return -EIO;
	431	}
	432
	433	rx6110 = devm_kzalloc(&client->dev, sizeof(*rx6110), GFP_KERNEL);
	434	if (!rx6110)
	435	return -ENOMEM;
	436
	437	rx6110->regmap = devm_regmap_init_i2c(client, &regmap_i2c_config);
	438	if (IS_ERR(rx6110->regmap)) {
	439	dev_err(&client->dev, "regmap init failed for rtc rx6110\n");
	440	return PTR_ERR(rx6110->regmap);
	441	}
	442
	443	i2c_set_clientdata(client, rx6110);
	444
	445	return rx6110_probe(rx6110, &client->dev);
	446	}
	447
8d69f62f JH	448	static const struct acpi_device_id rx6110_i2c_acpi_match[] = {
	449	{ "SECC6110" },
	450	{ }
	451	};
	452	MODULE_DEVICE_TABLE(acpi, rx6110_i2c_acpi_match);
	453
afa819c2 CH	454	static const struct i2c_device_id rx6110_i2c_id[] = {
	455	{ "rx6110", 0 },
	456	{ }
	457	};
	458	MODULE_DEVICE_TABLE(i2c, rx6110_i2c_id);
	459
	460	static struct i2c_driver rx6110_i2c_driver = {
	461	.driver = {
	462	.name = RX6110_DRIVER_NAME,
8d69f62f	463	.acpi_match_table = rx6110_i2c_acpi_match,
afa819c2	464	},
3f4a3322	465	.probe_new = rx6110_i2c_probe,
afa819c2 CH	466	.id_table = rx6110_i2c_id,
	467	};
	468
	469	static int rx6110_i2c_register(void)
	470	{
	471	return i2c_add_driver(&rx6110_i2c_driver);
	472	}
	473
	474	static void rx6110_i2c_unregister(void)
	475	{
	476	i2c_del_driver(&rx6110_i2c_driver);
	477	}
	478	#else
	479	static int rx6110_i2c_register(void)
	480	{
	481	return 0;
	482	}
	483
	484	static void rx6110_i2c_unregister(void)
	485	{
	486	}
	487	#endif /* CONFIG_I2C */
	488
	489	static int __init rx6110_module_init(void)
	490	{
	491	int ret;
	492
	493	ret = rx6110_spi_register();
	494	if (ret)
	495	return ret;
	496
	497	ret = rx6110_i2c_register();
	498	if (ret)
	499	rx6110_spi_unregister();
	500
	501	return ret;
	502	}
	503	module_init(rx6110_module_init);
	504
	505	static void __exit rx6110_module_exit(void)
	506	{
	507	rx6110_spi_unregister();
	508	rx6110_i2c_unregister();
	509	}
	510	module_exit(rx6110_module_exit);
68298c2d ST	511
	512	MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
	513	MODULE_DESCRIPTION("RX-6110 SA RTC driver");
	514	MODULE_LICENSE("GPL");