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authorJames Morris <jmorris@namei.org>2008-11-13 19:29:12 -0500
committerJames Morris <jmorris@namei.org>2008-11-13 19:29:12 -0500
commit2b828925652340277a889cbc11b2d0637f7cdaf7 (patch)
tree32fcb3d3e466fc419fad2d3717956a5b5ad3d35a /drivers/rtc/rtc-ds1390.c
parent3a3b7ce9336952ea7b9564d976d068a238976c9d (diff)
parent58e20d8d344b0ee083febb18c2b021d2427e56ca (diff)
Merge branch 'master' into next
Conflicts: security/keys/internal.h security/keys/process_keys.c security/keys/request_key.c Fixed conflicts above by using the non 'tsk' versions. Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'drivers/rtc/rtc-ds1390.c')
-rw-r--r--drivers/rtc/rtc-ds1390.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1390.c b/drivers/rtc/rtc-ds1390.c
new file mode 100644
index 000000000000..599e976bf014
--- /dev/null
+++ b/drivers/rtc/rtc-ds1390.c
@@ -0,0 +1,220 @@
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
40struct ds1390 {
41 struct rtc_device *rtc;
42 u8 txrx_buf[9]; /* cmd + 8 registers */
43};
44
45static 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
59static 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
81static 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
110static 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
130static int ds1390_read_time(struct device *dev, struct rtc_time *tm)
131{
132 return ds1390_get_datetime(dev, tm);
133}
134
135static int ds1390_set_time(struct device *dev, struct rtc_time *tm)
136{
137 return ds1390_set_datetime(dev, tm);
138}
139
140static const struct rtc_class_ops ds1390_rtc_ops = {
141 .read_time = ds1390_read_time,
142 .set_time = ds1390_set_time,
143};
144
145static 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
184static 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
197static 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
206static __init int ds1390_init(void)
207{
208 return spi_register_driver(&ds1390_driver);
209}
210module_init(ds1390_init);
211
212static __exit void ds1390_exit(void)
213{
214 spi_unregister_driver(&ds1390_driver);
215}
216module_exit(ds1390_exit);
217
218MODULE_DESCRIPTION("DS1390/93/94 SPI RTC driver");
219MODULE_AUTHOR("Mark Jackson <mpfj@mimc.co.uk>");
220MODULE_LICENSE("GPL");