diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1390.c')
-rw-r--r-- | drivers/rtc/rtc-ds1390.c | 220 |
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 00000000000..599e976bf01 --- /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 | |||
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"); | ||