[thirdparty/kernel/stable.git] / drivers / rtc / rtc-rx6110.c

/*
 * 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.
 *
 * This driver software is distributed as is, without any warranty of any kind,
 * either express or implied as further specified in the GNU Public License.
 * This software may be used and distributed according to the terms of the GNU
 * Public License, version 2 as published by the Free Software Foundation.
 * See the file COPYING in the main directory of this archive for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/spi/spi.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 struct regmap_config regmap_spi_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = RX6110_REG_IRQ,
	.read_flag_mask = 0x80,
};

/**
 * rx6110_probe - initialize rtc driver
 * @spi: pointer to spi device
 */
static int rx6110_probe(struct spi_device *spi)
{
	struct rx6110_data *rx6110;
	int err;

	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);

	rx6110->rtc = devm_rtc_device_register(&spi->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;
}

static int rx6110_remove(struct spi_device *spi)
{
	return 0;
}

static const struct spi_device_id rx6110_id[] = {
	{ "rx6110", 0 },
	{ }
};
MODULE_DEVICE_TABLE(spi, rx6110_id);

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

static struct spi_driver rx6110_driver = {
	.driver = {
		.name = RX6110_DRIVER_NAME,
		.of_match_table = of_match_ptr(rx6110_spi_of_match),
	},
	.probe		= rx6110_probe,
	.remove		= rx6110_remove,
	.id_table	= rx6110_id,
};

module_spi_driver(rx6110_driver);

MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
MODULE_DESCRIPTION("RX-6110 SA RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
68298c2d ST	1	/*
	2	* Driver for the Epson RTC module RX-6110 SA
	3	*
	4	* Copyright(C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
	5	* Copyright(C) SEIKO EPSON CORPORATION 2013. All rights reserved.
	6	*
	7	* This driver software is distributed as is, without any warranty of any kind,
	8	* either express or implied as further specified in the GNU Public License.
	9	* This software may be used and distributed according to the terms of the GNU
	10	* Public License, version 2 as published by the Free Software Foundation.
	11	* See the file COPYING in the main directory of this archive for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program. If not, see <http://www.gnu.org/licenses/>.
	15	*/
	16
	17	#include <linux/bcd.h>
	18	#include <linux/init.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/of_gpio.h>
	22	#include <linux/regmap.h>
	23	#include <linux/rtc.h>
f9bf089a DG	24	#include <linux/of.h>
f9bf089a DG	25	#include <linux/of_device.h>
68298c2d ST	26	#include <linux/spi/spi.h>
	27
	28	/* RX-6110 Register definitions */
	29	#define RX6110_REG_SEC 0x10
	30	#define RX6110_REG_MIN 0x11
	31	#define RX6110_REG_HOUR 0x12
	32	#define RX6110_REG_WDAY 0x13
	33	#define RX6110_REG_MDAY 0x14
	34	#define RX6110_REG_MONTH 0x15
	35	#define RX6110_REG_YEAR 0x16
	36	#define RX6110_REG_RES1 0x17
	37	#define RX6110_REG_ALMIN 0x18
	38	#define RX6110_REG_ALHOUR 0x19
	39	#define RX6110_REG_ALWDAY 0x1A
	40	#define RX6110_REG_TCOUNT0 0x1B
	41	#define RX6110_REG_TCOUNT1 0x1C
	42	#define RX6110_REG_EXT 0x1D
	43	#define RX6110_REG_FLAG 0x1E
	44	#define RX6110_REG_CTRL 0x1F
	45	#define RX6110_REG_USER0 0x20
	46	#define RX6110_REG_USER1 0x21
	47	#define RX6110_REG_USER2 0x22
	48	#define RX6110_REG_USER3 0x23
	49	#define RX6110_REG_USER4 0x24
	50	#define RX6110_REG_USER5 0x25
	51	#define RX6110_REG_USER6 0x26
	52	#define RX6110_REG_USER7 0x27
	53	#define RX6110_REG_USER8 0x28
	54	#define RX6110_REG_USER9 0x29
	55	#define RX6110_REG_USERA 0x2A
	56	#define RX6110_REG_USERB 0x2B
	57	#define RX6110_REG_USERC 0x2C
	58	#define RX6110_REG_USERD 0x2D
	59	#define RX6110_REG_USERE 0x2E
	60	#define RX6110_REG_USERF 0x2F
	61	#define RX6110_REG_RES2 0x30
	62	#define RX6110_REG_RES3 0x31
	63	#define RX6110_REG_IRQ 0x32
	64
	65	#define RX6110_BIT_ALARM_EN BIT(7)
	66
	67	/* Extension Register (1Dh) bit positions */
	68	#define RX6110_BIT_EXT_TSEL0 BIT(0)
	69	#define RX6110_BIT_EXT_TSEL1 BIT(1)
	70	#define RX6110_BIT_EXT_TSEL2 BIT(2)
	71	#define RX6110_BIT_EXT_WADA BIT(3)
	72	#define RX6110_BIT_EXT_TE BIT(4)
	73	#define RX6110_BIT_EXT_USEL BIT(5)
	74	#define RX6110_BIT_EXT_FSEL0 BIT(6)
	75	#define RX6110_BIT_EXT_FSEL1 BIT(7)
	76
	77	/* Flag Register (1Eh) bit positions */
	78	#define RX6110_BIT_FLAG_VLF BIT(1)
	79	#define RX6110_BIT_FLAG_AF BIT(3)
	80	#define RX6110_BIT_FLAG_TF BIT(4)
	81	#define RX6110_BIT_FLAG_UF BIT(5)
	82
	83	/* Control Register (1Fh) bit positions */
	84	#define RX6110_BIT_CTRL_TBKE BIT(0)
	85	#define RX6110_BIT_CTRL_TBKON BIT(1)
	86	#define RX6110_BIT_CTRL_TSTP BIT(2)
	87	#define RX6110_BIT_CTRL_AIE BIT(3)
	88	#define RX6110_BIT_CTRL_TIE BIT(4)
	89	#define RX6110_BIT_CTRL_UIE BIT(5)
90	#define RX6110_BIT_CTRL_STOP BIT(6)
91	#define RX6110_BIT_CTRL_TEST BIT(7)
92
93	enum {
94	RTC_SEC = 0,
95	RTC_MIN,
96	RTC_HOUR,
97	RTC_WDAY,
98	RTC_MDAY,
99	RTC_MONTH,
100	RTC_YEAR,
101	RTC_NR_TIME
102	};
103
104	#define RX6110_DRIVER_NAME "rx6110"
105
106	struct rx6110_data {
107	struct rtc_device *rtc;
108	struct regmap *regmap;
109	};
110
111	/**
112	* rx6110_rtc_tm_to_data - convert rtc_time to native time encoding
113	*
114	* @tm: holds date and time
115	* @data: holds the encoding in rx6110 native form
116	*/
117	static int rx6110_rtc_tm_to_data(struct rtc_time tm, u8 data)
118	{
a3f60bb3	119	pr_debug("%s: date %ptRr\n", __func__, tm);
68298c2d ST	120
	121	/*
	122	* The year in the RTC is a value between 0 and 99.
	123	* Assume that this represents the current century
	124	* and disregard all other values.
	125	*/
	126	if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
	127	return -EINVAL;
	128
	129	data[RTC_SEC] = bin2bcd(tm->tm_sec);
	130	data[RTC_MIN] = bin2bcd(tm->tm_min);
	131	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
	132	data[RTC_WDAY] = BIT(bin2bcd(tm->tm_wday));
	133	data[RTC_MDAY] = bin2bcd(tm->tm_mday);
	134	data[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
	135	data[RTC_YEAR] = bin2bcd(tm->tm_year % 100);
	136
	137	return 0;
	138	}
	139
	140	/**
	141	* rx6110_data_to_rtc_tm - convert native time encoding to rtc_time
	142	*
	143	* @data: holds the encoding in rx6110 native form
	144	* @tm: holds date and time
	145	*/
	146	static int rx6110_data_to_rtc_tm(u8 data, struct rtc_time tm)
	147	{
	148	tm->tm_sec = bcd2bin(data[RTC_SEC] & 0x7f);
	149	tm->tm_min = bcd2bin(data[RTC_MIN] & 0x7f);
	150	/* only 24-hour clock */
	151	tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
	152	tm->tm_wday = ffs(data[RTC_WDAY] & 0x7f);
	153	tm->tm_mday = bcd2bin(data[RTC_MDAY] & 0x3f);
	154	tm->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1f) - 1;
	155	tm->tm_year = bcd2bin(data[RTC_YEAR]) + 100;
	156
a3f60bb3	157	pr_debug("%s: date %ptRr\n", __func__, tm);
68298c2d ST	158
	159	/*
	160	* The year in the RTC is a value between 0 and 99.
	161	* Assume that this represents the current century
	162	* and disregard all other values.
	163	*/
	164	if (tm->tm_year < 100 \|\| tm->tm_year >= 200)
	165	return -EINVAL;
	166
	167	return 0;
	168	}
	169
	170	/**
	171	* rx6110_set_time - set the current time in the rx6110 registers
	172	*
	173	* @dev: the rtc device in use
	174	* @tm: holds date and time
	175	*
	176	* BUG: The HW assumes every year that is a multiple of 4 to be a leap
	177	* year. Next time this is wrong is 2100, which will not be a leap year
	178	*
	179	* Note: If STOP is not set/cleared, the clock will start when the seconds
	180	* register is written
	181	*
	182	*/
	183	static int rx6110_set_time(struct device dev, struct rtc_time tm)
	184	{
	185	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
	186	u8 data[RTC_NR_TIME];
	187	int ret;
	188
	189	ret = rx6110_rtc_tm_to_data(tm, data);
	190	if (ret < 0)
	191	return ret;
	192
	193	/* set STOP bit before changing clock/calendar */
	194	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
	195	RX6110_BIT_CTRL_STOP, RX6110_BIT_CTRL_STOP);
	196	if (ret)
	197	return ret;
	198
	199	ret = regmap_bulk_write(rx6110->regmap, RX6110_REG_SEC, data,
	200	RTC_NR_TIME);
	201	if (ret)
	202	return ret;
	203
	204	/* The time in the RTC is valid. Be sure to have VLF cleared. */
	205	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
	206	RX6110_BIT_FLAG_VLF, 0);
	207	if (ret)
	208	return ret;
	209
	210	/* clear STOP bit after changing clock/calendar */
	211	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_CTRL,
	212	RX6110_BIT_CTRL_STOP, 0);
	213
	214	return ret;
	215	}
	216
	217	/**
	218	* rx6110_get_time - get the current time from the rx6110 registers
	219	* @dev: the rtc device in use
	220	* @tm: holds date and time
	221	*/
222	static int rx6110_get_time(struct device dev, struct rtc_time tm)
223	{
224	struct rx6110_data *rx6110 = dev_get_drvdata(dev);
225	u8 data[RTC_NR_TIME];
226	int flags;
227	int ret;
228
229	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
230	if (ret)
231	return -EINVAL;
232
233	/* check for VLF Flag (set at power-on) */
234	if ((flags & RX6110_BIT_FLAG_VLF)) {
235	dev_warn(dev, "Voltage low, data is invalid.\n");
236	return -EINVAL;
237	}
238
239	/* read registers to date */
240	ret = regmap_bulk_read(rx6110->regmap, RX6110_REG_SEC, data,
241	RTC_NR_TIME);
242	if (ret)
243	return ret;
244
245	ret = rx6110_data_to_rtc_tm(data, tm);
246	if (ret)
247	return ret;
248
a3f60bb3	249	dev_dbg(dev, "%s: date %ptRr\n", __func__, tm);
68298c2d	250
22652ba7	251	return 0;
68298c2d ST	252	}
	253
	254	static const struct reg_sequence rx6110_default_regs[] = {
	255	{ RX6110_REG_RES1, 0xB8 },
	256	{ RX6110_REG_RES2, 0x00 },
	257	{ RX6110_REG_RES3, 0x10 },
	258	{ RX6110_REG_IRQ, 0x00 },
	259	{ RX6110_REG_ALMIN, 0x00 },
	260	{ RX6110_REG_ALHOUR, 0x00 },
	261	{ RX6110_REG_ALWDAY, 0x00 },
	262	};
	263
	264	/**
	265	* rx6110_init - initialize the rx6110 registers
	266	*
	267	* @rx6110: pointer to the rx6110 struct in use
	268	*
	269	*/
	270	static int rx6110_init(struct rx6110_data *rx6110)
	271	{
	272	struct rtc_device *rtc = rx6110->rtc;
	273	int flags;
	274	int ret;
	275
	276	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_EXT,
	277	RX6110_BIT_EXT_TE, 0);
	278	if (ret)
	279	return ret;
	280
	281	ret = regmap_register_patch(rx6110->regmap, rx6110_default_regs,
	282	ARRAY_SIZE(rx6110_default_regs));
	283	if (ret)
	284	return ret;
	285
	286	ret = regmap_read(rx6110->regmap, RX6110_REG_FLAG, &flags);
	287	if (ret)
	288	return ret;
	289
	290	/* check for VLF Flag (set at power-on) */
	291	if ((flags & RX6110_BIT_FLAG_VLF))
	292	dev_warn(&rtc->dev, "Voltage low, data loss detected.\n");
	293
	294	/* check for Alarm Flag */
	295	if (flags & RX6110_BIT_FLAG_AF)
	296	dev_warn(&rtc->dev, "An alarm may have been missed.\n");
	297
	298	/* check for Periodic Timer Flag */
	299	if (flags & RX6110_BIT_FLAG_TF)
	300	dev_warn(&rtc->dev, "Periodic timer was detected\n");
	301
	302	/* check for Update Timer Flag */
	303	if (flags & RX6110_BIT_FLAG_UF)
	304	dev_warn(&rtc->dev, "Update timer was detected\n");
	305
	306	/* clear all flags BUT VLF */
	307	ret = regmap_update_bits(rx6110->regmap, RX6110_REG_FLAG,
	308	RX6110_BIT_FLAG_AF \|
	309	RX6110_BIT_FLAG_UF \|
	310	RX6110_BIT_FLAG_TF,
	311	0);
	312
	313	return ret;
	314	}
	315
34c7b3ac	316	static const struct rtc_class_ops rx6110_rtc_ops = {
68298c2d ST	317	.read_time = rx6110_get_time,
	318	.set_time = rx6110_set_time,
	319	};
	320
	321	static struct regmap_config regmap_spi_config = {
	322	.reg_bits = 8,
	323	.val_bits = 8,
	324	.max_register = RX6110_REG_IRQ,
	325	.read_flag_mask = 0x80,
	326	};
	327
	328	/**
	329	* rx6110_probe - initialize rtc driver
	330	* @spi: pointer to spi device
	331	*/
	332	static int rx6110_probe(struct spi_device *spi)
	333	{
	334	struct rx6110_data *rx6110;
	335	int err;
	336
	337	if ((spi->bits_per_word && spi->bits_per_word != 8) \|\|
	338	(spi->max_speed_hz > 2000000) \|\|
	339	(spi->mode != (SPI_CS_HIGH \| SPI_CPOL \| SPI_CPHA))) {
	340	dev_warn(&spi->dev, "SPI settings: bits_per_word: %d, max_speed_hz: %d, mode: %xh\n",
	341	spi->bits_per_word, spi->max_speed_hz, spi->mode);
	342	dev_warn(&spi->dev, "driving device in an unsupported mode");
	343	}
	344
	345	rx6110 = devm_kzalloc(&spi->dev, sizeof(*rx6110), GFP_KERNEL);
	346	if (!rx6110)
	347	return -ENOMEM;
	348
	349	rx6110->regmap = devm_regmap_init_spi(spi, &regmap_spi_config);
	350	if (IS_ERR(rx6110->regmap)) {
	351	dev_err(&spi->dev, "regmap init failed for rtc rx6110\n");
	352	return PTR_ERR(rx6110->regmap);
	353	}
	354
	355	spi_set_drvdata(spi, rx6110);
	356
	357	rx6110->rtc = devm_rtc_device_register(&spi->dev,
	358	RX6110_DRIVER_NAME,
	359	&rx6110_rtc_ops, THIS_MODULE);
	360
	361	if (IS_ERR(rx6110->rtc))
	362	return PTR_ERR(rx6110->rtc);
	363
	364	err = rx6110_init(rx6110);
	365	if (err)
	366	return err;
	367
	368	rx6110->rtc->max_user_freq = 1;
	369
	370	return 0;
	371	}
	372
	373	static int rx6110_remove(struct spi_device *spi)
	374	{
	375	return 0;
	376	}
	377
	378	static const struct spi_device_id rx6110_id[] = {
	379	{ "rx6110", 0 },
	380	{ }
381	};
382	MODULE_DEVICE_TABLE(spi, rx6110_id);
383
f9bf089a DG	384	static const struct of_device_id rx6110_spi_of_match[] = {
	385	{ .compatible = "epson,rx6110" },
	386	{ },
	387	};
	388	MODULE_DEVICE_TABLE(of, rx6110_spi_of_match);
	389
68298c2d ST	390	static struct spi_driver rx6110_driver = {
	391	.driver = {
	392	.name = RX6110_DRIVER_NAME,
f9bf089a	393	.of_match_table = of_match_ptr(rx6110_spi_of_match),
68298c2d ST	394	},
	395	.probe = rx6110_probe,
	396	.remove = rx6110_remove,
	397	.id_table = rx6110_id,
	398	};
	399
	400	module_spi_driver(rx6110_driver);
	401
	402	MODULE_AUTHOR("Val Krutov <val.krutov@erd.epson.com>");
	403	MODULE_DESCRIPTION("RX-6110 SA RTC driver");
	404	MODULE_LICENSE("GPL");