sh_eth: fix EESIPR values for SH77{34|63}
[linux/fpc-iii.git] / drivers / rtc / rtc-ds1347.c
blobccfc9d43eb1e680956d32892e9bacfaddefafd1a
1 /* rtc-ds1347.c
3 * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible
4 * Real Time Clock
6 * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/platform_device.h>
18 #include <linux/rtc.h>
19 #include <linux/spi/spi.h>
20 #include <linux/bcd.h>
21 #include <linux/regmap.h>
23 /* Registers in ds1347 rtc */
25 #define DS1347_SECONDS_REG 0x01
26 #define DS1347_MINUTES_REG 0x03
27 #define DS1347_HOURS_REG 0x05
28 #define DS1347_DATE_REG 0x07
29 #define DS1347_MONTH_REG 0x09
30 #define DS1347_DAY_REG 0x0B
31 #define DS1347_YEAR_REG 0x0D
32 #define DS1347_CONTROL_REG 0x0F
33 #define DS1347_STATUS_REG 0x17
34 #define DS1347_CLOCK_BURST 0x3F
36 static const struct regmap_range ds1347_ranges[] = {
38 .range_min = DS1347_SECONDS_REG,
39 .range_max = DS1347_STATUS_REG,
43 static const struct regmap_access_table ds1347_access_table = {
44 .yes_ranges = ds1347_ranges,
45 .n_yes_ranges = ARRAY_SIZE(ds1347_ranges),
48 static int ds1347_read_time(struct device *dev, struct rtc_time *dt)
50 struct spi_device *spi = to_spi_device(dev);
51 struct regmap *map;
52 int err;
53 unsigned char buf[8];
55 map = spi_get_drvdata(spi);
57 err = regmap_bulk_read(map, DS1347_CLOCK_BURST, buf, 8);
58 if (err)
59 return err;
61 dt->tm_sec = bcd2bin(buf[0]);
62 dt->tm_min = bcd2bin(buf[1]);
63 dt->tm_hour = bcd2bin(buf[2] & 0x3F);
64 dt->tm_mday = bcd2bin(buf[3]);
65 dt->tm_mon = bcd2bin(buf[4]) - 1;
66 dt->tm_wday = bcd2bin(buf[5]) - 1;
67 dt->tm_year = bcd2bin(buf[6]) + 100;
69 return rtc_valid_tm(dt);
72 static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
74 struct spi_device *spi = to_spi_device(dev);
75 struct regmap *map;
76 unsigned char buf[8];
78 map = spi_get_drvdata(spi);
80 buf[0] = bin2bcd(dt->tm_sec);
81 buf[1] = bin2bcd(dt->tm_min);
82 buf[2] = (bin2bcd(dt->tm_hour) & 0x3F);
83 buf[3] = bin2bcd(dt->tm_mday);
84 buf[4] = bin2bcd(dt->tm_mon + 1);
85 buf[5] = bin2bcd(dt->tm_wday + 1);
87 /* year in linux is from 1900 i.e in range of 100
88 in rtc it is from 00 to 99 */
89 dt->tm_year = dt->tm_year % 100;
91 buf[6] = bin2bcd(dt->tm_year);
92 buf[7] = bin2bcd(0x00);
94 /* write the rtc settings */
95 return regmap_bulk_write(map, DS1347_CLOCK_BURST, buf, 8);
98 static const struct rtc_class_ops ds1347_rtc_ops = {
99 .read_time = ds1347_read_time,
100 .set_time = ds1347_set_time,
103 static int ds1347_probe(struct spi_device *spi)
105 struct rtc_device *rtc;
106 struct regmap_config config;
107 struct regmap *map;
108 unsigned int data;
109 int res;
111 memset(&config, 0, sizeof(config));
112 config.reg_bits = 8;
113 config.val_bits = 8;
114 config.read_flag_mask = 0x80;
115 config.max_register = 0x3F;
116 config.wr_table = &ds1347_access_table;
118 /* spi setup with ds1347 in mode 3 and bits per word as 8 */
119 spi->mode = SPI_MODE_3;
120 spi->bits_per_word = 8;
121 spi_setup(spi);
123 map = devm_regmap_init_spi(spi, &config);
125 if (IS_ERR(map)) {
126 dev_err(&spi->dev, "ds1347 regmap init spi failed\n");
127 return PTR_ERR(map);
130 spi_set_drvdata(spi, map);
132 /* RTC Settings */
133 res = regmap_read(map, DS1347_SECONDS_REG, &data);
134 if (res)
135 return res;
137 /* Disable the write protect of rtc */
138 regmap_read(map, DS1347_CONTROL_REG, &data);
139 data = data & ~(1<<7);
140 regmap_write(map, DS1347_CONTROL_REG, data);
142 /* Enable the oscillator , disable the oscillator stop flag,
143 and glitch filter to reduce current consumption */
144 regmap_read(map, DS1347_STATUS_REG, &data);
145 data = data & 0x1B;
146 regmap_write(map, DS1347_STATUS_REG, data);
148 /* display the settings */
149 regmap_read(map, DS1347_CONTROL_REG, &data);
150 dev_info(&spi->dev, "DS1347 RTC CTRL Reg = 0x%02x\n", data);
152 regmap_read(map, DS1347_STATUS_REG, &data);
153 dev_info(&spi->dev, "DS1347 RTC Status Reg = 0x%02x\n", data);
155 rtc = devm_rtc_device_register(&spi->dev, "ds1347",
156 &ds1347_rtc_ops, THIS_MODULE);
158 if (IS_ERR(rtc))
159 return PTR_ERR(rtc);
161 return 0;
164 static struct spi_driver ds1347_driver = {
165 .driver = {
166 .name = "ds1347",
168 .probe = ds1347_probe,
171 module_spi_driver(ds1347_driver);
173 MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER");
174 MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>");
175 MODULE_LICENSE("GPL v2");