[net-next-2.6.git] / drivers / rtc / rtc-ds1390.c

/*
 * rtc-ds1390.c -- driver for DS1390/93/94
 *
 * Copyright (C) 2008 Mercury IMC Ltd
 * Written by Mark Jackson <mpfj@mimc.co.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * NOTE : Currently this driver only supports the bare minimum for read
 * and write the RTC.  The extra features provided by the chip family
 * (alarms, trickle charger, different control registers) are unavailable.
 */

#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>

#define DS1390_REG_100THS		0x00
#define DS1390_REG_SECONDS		0x01
#define DS1390_REG_MINUTES		0x02
#define DS1390_REG_HOURS		0x03
#define DS1390_REG_DAY			0x04
#define DS1390_REG_DATE			0x05
#define DS1390_REG_MONTH_CENT		0x06
#define DS1390_REG_YEAR			0x07

#define DS1390_REG_ALARM_100THS		0x08
#define DS1390_REG_ALARM_SECONDS	0x09
#define DS1390_REG_ALARM_MINUTES	0x0A
#define DS1390_REG_ALARM_HOURS		0x0B
#define DS1390_REG_ALARM_DAY_DATE	0x0C

#define DS1390_REG_CONTROL		0x0D
#define DS1390_REG_STATUS		0x0E
#define DS1390_REG_TRICKLE		0x0F

struct ds1390 {
	struct rtc_device *rtc;
	u8 txrx_buf[9];	/* cmd + 8 registers */
};

static void ds1390_set_reg(struct device *dev, unsigned char address,
				unsigned char data)
{
	struct spi_device *spi = to_spi_device(dev);
	struct ds1390 *chip = dev_get_drvdata(dev);

	/* Set MSB to indicate write */
	chip->txrx_buf[0] = address | 0x80;
	chip->txrx_buf[1] = data;

	/* do the i/o */
	spi_write_then_read(spi, chip->txrx_buf, 2, NULL, 0);
}

static int ds1390_get_reg(struct device *dev, unsigned char address,
				unsigned char *data)
{
	struct spi_device *spi = to_spi_device(dev);
	struct ds1390 *chip = dev_get_drvdata(dev);
	int status;

	if (!data)
		return -EINVAL;

	/* Clear MSB to indicate read */
	chip->txrx_buf[0] = address & 0x7f;
	/* do the i/o */
	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 1);
	if (status != 0)
		return status;

	*data = chip->txrx_buf[1];

	return 0;
}

static int ds1390_get_datetime(struct device *dev, struct rtc_time *dt)
{
	struct spi_device *spi = to_spi_device(dev);
	struct ds1390 *chip = dev_get_drvdata(dev);
	int status;

	/* build the message */
	chip->txrx_buf[0] = DS1390_REG_SECONDS;

	/* do the i/o */
	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 8);
	if (status != 0)
		return status;

	/* The chip sends data in this order:
	 * Seconds, Minutes, Hours, Day, Date, Month / Century, Year */
	dt->tm_sec	= bcd2bin(chip->txrx_buf[0]);
	dt->tm_min	= bcd2bin(chip->txrx_buf[1]);
	dt->tm_hour	= bcd2bin(chip->txrx_buf[2]);
	dt->tm_wday	= bcd2bin(chip->txrx_buf[3]);
	dt->tm_mday	= bcd2bin(chip->txrx_buf[4]);
	/* mask off century bit */
	dt->tm_mon	= bcd2bin(chip->txrx_buf[5] & 0x7f) - 1;
	/* adjust for century bit */
	dt->tm_year = bcd2bin(chip->txrx_buf[6]) + ((chip->txrx_buf[5] & 0x80) ? 100 : 0);

	return rtc_valid_tm(dt);
}

static int ds1390_set_datetime(struct device *dev, struct rtc_time *dt)
{
	struct spi_device *spi = to_spi_device(dev);
	struct ds1390 *chip = dev_get_drvdata(dev);

	/* build the message */
	chip->txrx_buf[0] = DS1390_REG_SECONDS | 0x80;
	chip->txrx_buf[1] = bin2bcd(dt->tm_sec);
	chip->txrx_buf[2] = bin2bcd(dt->tm_min);
	chip->txrx_buf[3] = bin2bcd(dt->tm_hour);
	chip->txrx_buf[4] = bin2bcd(dt->tm_wday);
	chip->txrx_buf[5] = bin2bcd(dt->tm_mday);
	chip->txrx_buf[6] = bin2bcd(dt->tm_mon + 1) |
				((dt->tm_year > 99) ? 0x80 : 0x00);
	chip->txrx_buf[7] = bin2bcd(dt->tm_year % 100);

	/* do the i/o */
	return spi_write_then_read(spi, chip->txrx_buf, 8, NULL, 0);
}

static int ds1390_read_time(struct device *dev, struct rtc_time *tm)
{
	return ds1390_get_datetime(dev, tm);
}

static int ds1390_set_time(struct device *dev, struct rtc_time *tm)
{
	return ds1390_set_datetime(dev, tm);
}

static const struct rtc_class_ops ds1390_rtc_ops = {
	.read_time	= ds1390_read_time,
	.set_time	= ds1390_set_time,
};

static int __devinit ds1390_probe(struct spi_device *spi)
{
	struct rtc_device *rtc;
	unsigned char tmp;
	struct ds1390 *chip;
	int res;

	printk(KERN_DEBUG "DS1390 SPI RTC driver\n");

	rtc = rtc_device_register("ds1390",
				&spi->dev, &ds1390_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		printk(KERN_ALERT "RTC : unable to register device\n");
		return PTR_ERR(rtc);
	}

	spi->mode = SPI_MODE_3;
	spi->bits_per_word = 8;
	spi_setup(spi);

	chip = kzalloc(sizeof *chip, GFP_KERNEL);
	if (!chip) {
		printk(KERN_ALERT "RTC : unable to allocate device memory\n");
		rtc_device_unregister(rtc);
		return -ENOMEM;
	}
	chip->rtc = rtc;
	dev_set_drvdata(&spi->dev, chip);

	res = ds1390_get_reg(&spi->dev, DS1390_REG_SECONDS, &tmp);
	if (res) {
		printk(KERN_ALERT "RTC : unable to read device\n");
		rtc_device_unregister(rtc);
		return res;
	}

	return 0;
}

static int __devexit ds1390_remove(struct spi_device *spi)
{
	struct ds1390 *chip = platform_get_drvdata(spi);
	struct rtc_device *rtc = chip->rtc;

	if (rtc)
		rtc_device_unregister(rtc);

	kfree(chip);

	return 0;
}

static struct spi_driver ds1390_driver = {
	.driver = {
		.name	= "rtc-ds1390",
		.owner	= THIS_MODULE,
	},
	.probe	= ds1390_probe,
	.remove = __devexit_p(ds1390_remove),
};

static __init int ds1390_init(void)
{
	return spi_register_driver(&ds1390_driver);
}
module_init(ds1390_init);

static __exit void ds1390_exit(void)
{
	spi_unregister_driver(&ds1390_driver);
}
module_exit(ds1390_exit);

MODULE_DESCRIPTION("DS1390/93/94 SPI RTC driver");
MODULE_AUTHOR("Mark Jackson <mpfj@mimc.co.uk>");
MODULE_LICENSE("GPL");
Commit	Line	Data
06de1808 MJ	1	/*
	2	* rtc-ds1390.c -- driver for DS1390/93/94
	3	*
	4	* Copyright (C) 2008 Mercury IMC Ltd
	5	* Written by Mark Jackson <mpfj@mimc.co.uk>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* NOTE : Currently this driver only supports the bare minimum for read
	12	* and write the RTC. The extra features provided by the chip family
	13	* (alarms, trickle charger, different control registers) are unavailable.
	14	*/
	15
	16	#include <linux/platform_device.h>
	17	#include <linux/rtc.h>
	18	#include <linux/spi/spi.h>
	19	#include <linux/bcd.h>
	20
	21	#define DS1390_REG_100THS 0x00
	22	#define DS1390_REG_SECONDS 0x01
	23	#define DS1390_REG_MINUTES 0x02
	24	#define DS1390_REG_HOURS 0x03
	25	#define DS1390_REG_DAY 0x04
	26	#define DS1390_REG_DATE 0x05
	27	#define DS1390_REG_MONTH_CENT 0x06
	28	#define DS1390_REG_YEAR 0x07
	29
	30	#define DS1390_REG_ALARM_100THS 0x08
	31	#define DS1390_REG_ALARM_SECONDS 0x09
	32	#define DS1390_REG_ALARM_MINUTES 0x0A
	33	#define DS1390_REG_ALARM_HOURS 0x0B
	34	#define DS1390_REG_ALARM_DAY_DATE 0x0C
	35
	36	#define DS1390_REG_CONTROL 0x0D
	37	#define DS1390_REG_STATUS 0x0E
	38	#define DS1390_REG_TRICKLE 0x0F
	39
	40	struct ds1390 {
	41	struct rtc_device *rtc;
	42	u8 txrx_buf[9]; /* cmd + 8 registers */
	43	};
	44
	45	static void ds1390_set_reg(struct device *dev, unsigned char address,
	46	unsigned char data)
	47	{
	48	struct spi_device *spi = to_spi_device(dev);
	49	struct ds1390 *chip = dev_get_drvdata(dev);
	50
	51	/* Set MSB to indicate write */
	52	chip->txrx_buf[0] = address \| 0x80;
	53	chip->txrx_buf[1] = data;
	54
	55	/* do the i/o */
	56	spi_write_then_read(spi, chip->txrx_buf, 2, NULL, 0);
	57	}
	58
	59	static int ds1390_get_reg(struct device *dev, unsigned char address,
	60	unsigned char *data)
	61	{
	62	struct spi_device *spi = to_spi_device(dev);
	63	struct ds1390 *chip = dev_get_drvdata(dev);
	64	int status;
65
66	if (!data)
67	return -EINVAL;
68
69	/* Clear MSB to indicate read */
70	chip->txrx_buf[0] = address & 0x7f;
71	/* do the i/o */
72	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 1);
73	if (status != 0)
74	return status;
75
76	*data = chip->txrx_buf[1];
77
78	return 0;
79	}
80
81	static int ds1390_get_datetime(struct device dev, struct rtc_time dt)
82	{
83	struct spi_device *spi = to_spi_device(dev);
84	struct ds1390 *chip = dev_get_drvdata(dev);
85	int status;
86
87	/* build the message */
88	chip->txrx_buf[0] = DS1390_REG_SECONDS;
89
90	/* do the i/o */
91	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 8);
92	if (status != 0)
93	return status;
94
95	/* The chip sends data in this order:
96	* Seconds, Minutes, Hours, Day, Date, Month / Century, Year */
97	dt->tm_sec = bcd2bin(chip->txrx_buf[0]);
98	dt->tm_min = bcd2bin(chip->txrx_buf[1]);
99	dt->tm_hour = bcd2bin(chip->txrx_buf[2]);
100	dt->tm_wday = bcd2bin(chip->txrx_buf[3]);
101	dt->tm_mday = bcd2bin(chip->txrx_buf[4]);
102	/* mask off century bit */
103	dt->tm_mon = bcd2bin(chip->txrx_buf[5] & 0x7f) - 1;
104	/* adjust for century bit */
105	dt->tm_year = bcd2bin(chip->txrx_buf[6]) + ((chip->txrx_buf[5] & 0x80) ? 100 : 0);
106
107	return rtc_valid_tm(dt);
108	}
109
110	static int ds1390_set_datetime(struct device dev, struct rtc_time dt)
111	{
112	struct spi_device *spi = to_spi_device(dev);
113	struct ds1390 *chip = dev_get_drvdata(dev);
114
115	/* build the message */
116	chip->txrx_buf[0] = DS1390_REG_SECONDS \| 0x80;
117	chip->txrx_buf[1] = bin2bcd(dt->tm_sec);
118	chip->txrx_buf[2] = bin2bcd(dt->tm_min);
119	chip->txrx_buf[3] = bin2bcd(dt->tm_hour);
120	chip->txrx_buf[4] = bin2bcd(dt->tm_wday);
121	chip->txrx_buf[5] = bin2bcd(dt->tm_mday);
122	chip->txrx_buf[6] = bin2bcd(dt->tm_mon + 1) \|
123	((dt->tm_year > 99) ? 0x80 : 0x00);
124	chip->txrx_buf[7] = bin2bcd(dt->tm_year % 100);
125
126	/* do the i/o */
127	return spi_write_then_read(spi, chip->txrx_buf, 8, NULL, 0);
128	}
129
130	static int ds1390_read_time(struct device dev, struct rtc_time tm)
131	{
132	return ds1390_get_datetime(dev, tm);
133	}
134
135	static int ds1390_set_time(struct device dev, struct rtc_time tm)
136	{
137	return ds1390_set_datetime(dev, tm);
138	}
139
140	static const struct rtc_class_ops ds1390_rtc_ops = {
141	.read_time = ds1390_read_time,
142	.set_time = ds1390_set_time,
143	};
144
145	static int __devinit ds1390_probe(struct spi_device *spi)
146	{
147	struct rtc_device *rtc;
148	unsigned char tmp;
149	struct ds1390 *chip;
150	int res;
151
152	printk(KERN_DEBUG "DS1390 SPI RTC driver\n");
153
154	rtc = rtc_device_register("ds1390",
155	&spi->dev, &ds1390_rtc_ops, THIS_MODULE);
156	if (IS_ERR(rtc)) {
157	printk(KERN_ALERT "RTC : unable to register device\n");
158	return PTR_ERR(rtc);
159	}
160
161	spi->mode = SPI_MODE_3;
162	spi->bits_per_word = 8;
163	spi_setup(spi);
164
165	chip = kzalloc(sizeof *chip, GFP_KERNEL);
166	if (!chip) {
167	printk(KERN_ALERT "RTC : unable to allocate device memory\n");
168	rtc_device_unregister(rtc);
169	return -ENOMEM;
170	}
171	chip->rtc = rtc;
172	dev_set_drvdata(&spi->dev, chip);
173
174	res = ds1390_get_reg(&spi->dev, DS1390_REG_SECONDS, &tmp);
175	if (res) {
176	printk(KERN_ALERT "RTC : unable to read device\n");
177	rtc_device_unregister(rtc);
178	return res;
179	}
180
181	return 0;
182	}
183
184	static int __devexit ds1390_remove(struct spi_device *spi)
185	{
186	struct ds1390 *chip = platform_get_drvdata(spi);
187	struct rtc_device *rtc = chip->rtc;
188
189	if (rtc)
190	rtc_device_unregister(rtc);
191
192	kfree(chip);
193
194	return 0;
195	}
196
197	static struct spi_driver ds1390_driver = {
198	.driver = {
199	.name = "rtc-ds1390",
200	.owner = THIS_MODULE,
201	},
202	.probe = ds1390_probe,
203	.remove = __devexit_p(ds1390_remove),
204	};
205
206	static __init int ds1390_init(void)
207	{
208	return spi_register_driver(&ds1390_driver);
209	}
210	module_init(ds1390_init);
211
212	static __exit void ds1390_exit(void)
213	{
214	spi_unregister_driver(&ds1390_driver);
215	}
216	module_exit(ds1390_exit);
217
218	MODULE_DESCRIPTION("DS1390/93/94 SPI RTC driver");
219	MODULE_AUTHOR("Mark Jackson <mpfj@mimc.co.uk>");
220	MODULE_LICENSE("GPL");