1/*
  2 * Driver for TI BQ32000 RTC.
  3 *
  4 * Copyright (C) 2009 Semihalf.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/i2c.h>
 13#include <linux/rtc.h>
 14#include <linux/init.h>
 15#include <linux/errno.h>
 16#include <linux/bcd.h>
 17
 18#define BQ32K_SECONDS		0x00	/* Seconds register address */
 19#define BQ32K_SECONDS_MASK	0x7F	/* Mask over seconds value */
 20#define BQ32K_STOP		0x80	/* Oscillator Stop flat */
 21
 22#define BQ32K_MINUTES		0x01	/* Minutes register address */
 23#define BQ32K_MINUTES_MASK	0x7F	/* Mask over minutes value */
 24#define BQ32K_OF		0x80	/* Oscillator Failure flag */
 25
 26#define BQ32K_HOURS_MASK	0x3F	/* Mask over hours value */
 27#define BQ32K_CENT		0x40	/* Century flag */
 28#define BQ32K_CENT_EN		0x80	/* Century flag enable bit */
 29
 30struct bq32k_regs {
 31	uint8_t		seconds;
 32	uint8_t		minutes;
 33	uint8_t		cent_hours;
 34	uint8_t		day;
 35	uint8_t		date;
 36	uint8_t		month;
 37	uint8_t		years;
 38};
 39
 40static struct i2c_driver bq32k_driver;
 41
 42static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len)
 43{
 44	struct i2c_client *client = to_i2c_client(dev);
 45	struct i2c_msg msgs[] = {
 46		{
 47			.addr = client->addr,
 48			.flags = 0,
 49			.len = 1,
 50			.buf = &off,
 51		}, {
 52			.addr = client->addr,
 53			.flags = I2C_M_RD,
 54			.len = len,
 55			.buf = data,
 56		}
 57	};
 58
 59	if (i2c_transfer(client->adapter, msgs, 2) == 2)
 60		return 0;
 61
 62	return -EIO;
 63}
 64
 65static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len)
 66{
 67	struct i2c_client *client = to_i2c_client(dev);
 68	uint8_t buffer[len + 1];
 69
 70	buffer[0] = off;
 71	memcpy(&buffer[1], data, len);
 72
 73	if (i2c_master_send(client, buffer, len + 1) == len + 1)
 74		return 0;
 75
 76	return -EIO;
 77}
 78
 79static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
 80{
 81	struct bq32k_regs regs;
 82	int error;
 83
 84	error = bq32k_read(dev, &regs, 0, sizeof(regs));
 85	if (error)
 86		return error;
 87
 88	tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
 89	tm->tm_min = bcd2bin(regs.minutes & BQ32K_SECONDS_MASK);
 90	tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
 91	tm->tm_mday = bcd2bin(regs.date);
 92	tm->tm_wday = bcd2bin(regs.day) - 1;
 93	tm->tm_mon = bcd2bin(regs.month) - 1;
 94	tm->tm_year = bcd2bin(regs.years) +
 95				((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
 96
 97	return rtc_valid_tm(tm);
 98}
 99
100static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
101{
102	struct bq32k_regs regs;
103
104	regs.seconds = bin2bcd(tm->tm_sec);
105	regs.minutes = bin2bcd(tm->tm_min);
106	regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN;
107	regs.day = bin2bcd(tm->tm_wday + 1);
108	regs.date = bin2bcd(tm->tm_mday);
109	regs.month = bin2bcd(tm->tm_mon + 1);
110
111	if (tm->tm_year >= 100) {
112		regs.cent_hours |= BQ32K_CENT;
113		regs.years = bin2bcd(tm->tm_year - 100);
114	} else
115		regs.years = bin2bcd(tm->tm_year);
116
117	return bq32k_write(dev, &regs, 0, sizeof(regs));
118}
119
120static const struct rtc_class_ops bq32k_rtc_ops = {
121	.read_time	= bq32k_rtc_read_time,
122	.set_time	= bq32k_rtc_set_time,
123};
124
125static int bq32k_probe(struct i2c_client *client,
126				const struct i2c_device_id *id)
127{
128	struct device *dev = &client->dev;
129	struct rtc_device *rtc;
130	uint8_t reg;
131	int error;
132
133	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
134		return -ENODEV;
135
136	/* Check Oscillator Stop flag */
137	error = bq32k_read(dev, &reg, BQ32K_SECONDS, 1);
138	if (!error && (reg & BQ32K_STOP)) {
139		dev_warn(dev, "Oscillator was halted. Restarting...\n");
140		reg &= ~BQ32K_STOP;
141		error = bq32k_write(dev, &reg, BQ32K_SECONDS, 1);
142	}
143	if (error)
144		return error;
145
146	/* Check Oscillator Failure flag */
147	error = bq32k_read(dev, &reg, BQ32K_MINUTES, 1);
148	if (!error && (reg & BQ32K_OF)) {
149		dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
150		reg &= ~BQ32K_OF;
151		error = bq32k_write(dev, &reg, BQ32K_MINUTES, 1);
152	}
153	if (error)
154		return error;
155
156	rtc = rtc_device_register(bq32k_driver.driver.name, &client->dev,
157						&bq32k_rtc_ops, THIS_MODULE);
158	if (IS_ERR(rtc))
159		return PTR_ERR(rtc);
160
161	i2c_set_clientdata(client, rtc);
162
163	return 0;
164}
165
166static int __devexit bq32k_remove(struct i2c_client *client)
167{
168	struct rtc_device *rtc = i2c_get_clientdata(client);
169
170	rtc_device_unregister(rtc);
171	return 0;
172}
173
174static const struct i2c_device_id bq32k_id[] = {
175	{ "bq32000", 0 },
176	{ }
177};
178MODULE_DEVICE_TABLE(i2c, bq32k_id);
179
180static struct i2c_driver bq32k_driver = {
181	.driver = {
182		.name	= "bq32k",
183		.owner	= THIS_MODULE,
184	},
185	.probe		= bq32k_probe,
186	.remove		= __devexit_p(bq32k_remove),
187	.id_table	= bq32k_id,
188};
189
190static __init int bq32k_init(void)
191{
192	return i2c_add_driver(&bq32k_driver);
193}
194module_init(bq32k_init);
195
196static __exit void bq32k_exit(void)
197{
198	i2c_del_driver(&bq32k_driver);
199}
200module_exit(bq32k_exit);
201
202MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>");
203MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver");
204MODULE_LICENSE("GPL");

  1/*
  2 * Driver for TI BQ32000 RTC.
  3 *
  4 * Copyright (C) 2009 Semihalf.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/i2c.h>
 13#include <linux/rtc.h>
 14#include <linux/init.h>
 15#include <linux/errno.h>
 16#include <linux/bcd.h>
 17
 18#define BQ32K_SECONDS		0x00	/* Seconds register address */
 19#define BQ32K_SECONDS_MASK	0x7F	/* Mask over seconds value */
 20#define BQ32K_STOP		0x80	/* Oscillator Stop flat */
 21
 22#define BQ32K_MINUTES		0x01	/* Minutes register address */
 23#define BQ32K_MINUTES_MASK	0x7F	/* Mask over minutes value */
 24#define BQ32K_OF		0x80	/* Oscillator Failure flag */
 25
 26#define BQ32K_HOURS_MASK	0x3F	/* Mask over hours value */
 27#define BQ32K_CENT		0x40	/* Century flag */
 28#define BQ32K_CENT_EN		0x80	/* Century flag enable bit */
 29
 30struct bq32k_regs {
 31	uint8_t		seconds;
 32	uint8_t		minutes;
 33	uint8_t		cent_hours;
 34	uint8_t		day;
 35	uint8_t		date;
 36	uint8_t		month;
 37	uint8_t		years;
 38};
 39
 40static struct i2c_driver bq32k_driver;
 41
 42static int bq32k_read(struct device *dev, void *data, uint8_t off, uint8_t len)
 43{
 44	struct i2c_client *client = to_i2c_client(dev);
 45	struct i2c_msg msgs[] = {
 46		{
 47			.addr = client->addr,
 48			.flags = 0,
 49			.len = 1,
 50			.buf = &off,
 51		}, {
 52			.addr = client->addr,
 53			.flags = I2C_M_RD,
 54			.len = len,
 55			.buf = data,
 56		}
 57	};
 58
 59	if (i2c_transfer(client->adapter, msgs, 2) == 2)
 60		return 0;
 61
 62	return -EIO;
 63}
 64
 65static int bq32k_write(struct device *dev, void *data, uint8_t off, uint8_t len)
 66{
 67	struct i2c_client *client = to_i2c_client(dev);
 68	uint8_t buffer[len + 1];
 69
 70	buffer[0] = off;
 71	memcpy(&buffer[1], data, len);
 72
 73	if (i2c_master_send(client, buffer, len + 1) == len + 1)
 74		return 0;
 75
 76	return -EIO;
 77}
 78
 79static int bq32k_rtc_read_time(struct device *dev, struct rtc_time *tm)
 80{
 81	struct bq32k_regs regs;
 82	int error;
 83
 84	error = bq32k_read(dev, &regs, 0, sizeof(regs));
 85	if (error)
 86		return error;
 87
 88	tm->tm_sec = bcd2bin(regs.seconds & BQ32K_SECONDS_MASK);
 89	tm->tm_min = bcd2bin(regs.minutes & BQ32K_SECONDS_MASK);
 90	tm->tm_hour = bcd2bin(regs.cent_hours & BQ32K_HOURS_MASK);
 91	tm->tm_mday = bcd2bin(regs.date);
 92	tm->tm_wday = bcd2bin(regs.day) - 1;
 93	tm->tm_mon = bcd2bin(regs.month) - 1;
 94	tm->tm_year = bcd2bin(regs.years) +
 95				((regs.cent_hours & BQ32K_CENT) ? 100 : 0);
 96
 97	return rtc_valid_tm(tm);
 98}
 99
100static int bq32k_rtc_set_time(struct device *dev, struct rtc_time *tm)
101{
102	struct bq32k_regs regs;
103
104	regs.seconds = bin2bcd(tm->tm_sec);
105	regs.minutes = bin2bcd(tm->tm_min);
106	regs.cent_hours = bin2bcd(tm->tm_hour) | BQ32K_CENT_EN;
107	regs.day = bin2bcd(tm->tm_wday + 1);
108	regs.date = bin2bcd(tm->tm_mday);
109	regs.month = bin2bcd(tm->tm_mon + 1);
110
111	if (tm->tm_year >= 100) {
112		regs.cent_hours |= BQ32K_CENT;
113		regs.years = bin2bcd(tm->tm_year - 100);
114	} else
115		regs.years = bin2bcd(tm->tm_year);
116
117	return bq32k_write(dev, &regs, 0, sizeof(regs));
118}
119
120static const struct rtc_class_ops bq32k_rtc_ops = {
121	.read_time	= bq32k_rtc_read_time,
122	.set_time	= bq32k_rtc_set_time,
123};
124
125static int bq32k_probe(struct i2c_client *client,
126				const struct i2c_device_id *id)
127{
128	struct device *dev = &client->dev;
129	struct rtc_device *rtc;
130	uint8_t reg;
131	int error;
132
133	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
134		return -ENODEV;
135
136	/* Check Oscillator Stop flag */
137	error = bq32k_read(dev, &reg, BQ32K_SECONDS, 1);
138	if (!error && (reg & BQ32K_STOP)) {
139		dev_warn(dev, "Oscillator was halted. Restarting...\n");
140		reg &= ~BQ32K_STOP;
141		error = bq32k_write(dev, &reg, BQ32K_SECONDS, 1);
142	}
143	if (error)
144		return error;
145
146	/* Check Oscillator Failure flag */
147	error = bq32k_read(dev, &reg, BQ32K_MINUTES, 1);
148	if (!error && (reg & BQ32K_OF)) {
149		dev_warn(dev, "Oscillator Failure. Check RTC battery.\n");
150		reg &= ~BQ32K_OF;
151		error = bq32k_write(dev, &reg, BQ32K_MINUTES, 1);
152	}
153	if (error)
154		return error;
155
156	rtc = rtc_device_register(bq32k_driver.driver.name, &client->dev,
157						&bq32k_rtc_ops, THIS_MODULE);
158	if (IS_ERR(rtc))
159		return PTR_ERR(rtc);
160
161	i2c_set_clientdata(client, rtc);
162
163	return 0;
164}
165
166static int __devexit bq32k_remove(struct i2c_client *client)
167{
168	struct rtc_device *rtc = i2c_get_clientdata(client);
169
170	rtc_device_unregister(rtc);
171	return 0;
172}
173
174static const struct i2c_device_id bq32k_id[] = {
175	{ "bq32000", 0 },
176	{ }
177};
178MODULE_DEVICE_TABLE(i2c, bq32k_id);
179
180static struct i2c_driver bq32k_driver = {
181	.driver = {
182		.name	= "bq32k",
183		.owner	= THIS_MODULE,
184	},
185	.probe		= bq32k_probe,
186	.remove		= __devexit_p(bq32k_remove),
187	.id_table	= bq32k_id,
188};
189
190module_i2c_driver(bq32k_driver);
 
 
 
 
 
 
 
 
 
 
191
192MODULE_AUTHOR("Semihalf, Piotr Ziecik <kosmo@semihalf.com>");
193MODULE_DESCRIPTION("TI BQ32000 I2C RTC driver");
194MODULE_LICENSE("GPL");