diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:22:16 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:22:16 -0700 |
commit | 76ca7d1cca761bb9712dfcad9a27d70b520874ae (patch) | |
tree | 4af495beaeee26b126e3dc6f0aa644e8e0b9e24e /drivers/rtc/rtc-ds1347.c | |
parent | d0cb5f71c5cde8e1ef6d03983641366800ceabdb (diff) | |
parent | 8d81e29fae18b93ab51f308b31babe1a6eb04314 (diff) |
Merge branch 'akpm' (incoming from Andrew)
Merge first patch-bomb from Andrew Morton:
- Various misc bits
- kmemleak fixes
- small befs, codafs, cifs, efs, freexxfs, hfsplus, minixfs, reiserfs things
- fanotify
- I appear to have become SuperH maintainer
- ocfs2 updates
- direct-io tweaks
- a bit of the MM queue
- printk updates
- MAINTAINERS maintenance
- some backlight things
- lib/ updates
- checkpatch updates
- the rtc queue
- nilfs2 updates
- Small Documentation/ updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (237 commits)
Documentation/SubmittingPatches: remove references to patch-scripts
Documentation/SubmittingPatches: update some dead URLs
Documentation/filesystems/ntfs.txt: remove changelog reference
Documentation/kmemleak.txt: updates
fs/reiserfs/super.c: add __init to init_inodecache
fs/reiserfs: move prototype declaration to header file
fs/hfsplus/attributes.c: add __init to hfsplus_create_attr_tree_cache()
fs/hfsplus/extents.c: fix concurrent acess of alloc_blocks
fs/hfsplus/extents.c: remove unused variable in hfsplus_get_block
nilfs2: update project's web site in nilfs2.txt
nilfs2: update MAINTAINERS file entries fix
nilfs2: verify metadata sizes read from disk
nilfs2: add FITRIM ioctl support for nilfs2
nilfs2: add nilfs_sufile_trim_fs to trim clean segs
nilfs2: implementation of NILFS_IOCTL_SET_SUINFO ioctl
nilfs2: add nilfs_sufile_set_suinfo to update segment usage
nilfs2: add struct nilfs_suinfo_update and flags
nilfs2: update MAINTAINERS file entries
fs/coda/inode.c: add __init to init_inodecache()
BEFS: logging cleanup
...
Diffstat (limited to 'drivers/rtc/rtc-ds1347.c')
-rw-r--r-- | drivers/rtc/rtc-ds1347.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c new file mode 100644 index 00000000000..c82b4c05032 --- /dev/null +++ b/drivers/rtc/rtc-ds1347.c @@ -0,0 +1,166 @@ +/* rtc-ds1347.c + * + * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible + * Real Time Clock + * + * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> + * + * 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. + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/spi/spi.h> +#include <linux/bcd.h> + +/* Registers in ds1347 rtc */ + +#define DS1347_SECONDS_REG 0x01 +#define DS1347_MINUTES_REG 0x03 +#define DS1347_HOURS_REG 0x05 +#define DS1347_DATE_REG 0x07 +#define DS1347_MONTH_REG 0x09 +#define DS1347_DAY_REG 0x0B +#define DS1347_YEAR_REG 0x0D +#define DS1347_CONTROL_REG 0x0F +#define DS1347_STATUS_REG 0x17 +#define DS1347_CLOCK_BURST 0x3F + +static int ds1347_read_reg(struct device *dev, unsigned char address, + unsigned char *data) +{ + struct spi_device *spi = to_spi_device(dev); + + *data = address | 0x80; + + return spi_write_then_read(spi, data, 1, data, 1); +} + +static int ds1347_write_reg(struct device *dev, unsigned char address, + unsigned char data) +{ + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[2]; + + buf[0] = address & 0x7F; + buf[1] = data; + + return spi_write_then_read(spi, buf, 2, NULL, 0); +} + +static int ds1347_read_time(struct device *dev, struct rtc_time *dt) +{ + struct spi_device *spi = to_spi_device(dev); + int err; + unsigned char buf[8]; + + buf[0] = DS1347_CLOCK_BURST | 0x80; + + err = spi_write_then_read(spi, buf, 1, buf, 8); + if (err) + return err; + + dt->tm_sec = bcd2bin(buf[0]); + dt->tm_min = bcd2bin(buf[1]); + dt->tm_hour = bcd2bin(buf[2] & 0x3F); + dt->tm_mday = bcd2bin(buf[3]); + dt->tm_mon = bcd2bin(buf[4]) - 1; + dt->tm_wday = bcd2bin(buf[5]) - 1; + dt->tm_year = bcd2bin(buf[6]) + 100; + + return rtc_valid_tm(dt); +} + +static int ds1347_set_time(struct device *dev, struct rtc_time *dt) +{ + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[9]; + + buf[0] = DS1347_CLOCK_BURST & 0x7F; + buf[1] = bin2bcd(dt->tm_sec); + buf[2] = bin2bcd(dt->tm_min); + buf[3] = (bin2bcd(dt->tm_hour) & 0x3F); + buf[4] = bin2bcd(dt->tm_mday); + buf[5] = bin2bcd(dt->tm_mon + 1); + buf[6] = bin2bcd(dt->tm_wday + 1); + + /* year in linux is from 1900 i.e in range of 100 + in rtc it is from 00 to 99 */ + dt->tm_year = dt->tm_year % 100; + + buf[7] = bin2bcd(dt->tm_year); + buf[8] = bin2bcd(0x00); + + /* write the rtc settings */ + return spi_write_then_read(spi, buf, 9, NULL, 0); +} + +static const struct rtc_class_ops ds1347_rtc_ops = { + .read_time = ds1347_read_time, + .set_time = ds1347_set_time, +}; + +static int ds1347_probe(struct spi_device *spi) +{ + struct rtc_device *rtc; + unsigned char data; + int res; + + /* spi setup with ds1347 in mode 3 and bits per word as 8 */ + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + /* RTC Settings */ + res = ds1347_read_reg(&spi->dev, DS1347_SECONDS_REG, &data); + if (res) + return res; + + /* Disable the write protect of rtc */ + ds1347_read_reg(&spi->dev, DS1347_CONTROL_REG, &data); + data = data & ~(1<<7); + ds1347_write_reg(&spi->dev, DS1347_CONTROL_REG, data); + + /* Enable the oscillator , disable the oscillator stop flag, + and glitch filter to reduce current consumption */ + ds1347_read_reg(&spi->dev, DS1347_STATUS_REG, &data); + data = data & 0x1B; + ds1347_write_reg(&spi->dev, DS1347_STATUS_REG, data); + + /* display the settings */ + ds1347_read_reg(&spi->dev, DS1347_CONTROL_REG, &data); + dev_info(&spi->dev, "DS1347 RTC CTRL Reg = 0x%02x\n", data); + + ds1347_read_reg(&spi->dev, DS1347_STATUS_REG, &data); + dev_info(&spi->dev, "DS1347 RTC Status Reg = 0x%02x\n", data); + + rtc = devm_rtc_device_register(&spi->dev, "ds1347", + &ds1347_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + spi_set_drvdata(spi, rtc); + + return 0; +} + +static struct spi_driver ds1347_driver = { + .driver = { + .name = "ds1347", + .owner = THIS_MODULE, + }, + .probe = ds1347_probe, +}; + +module_spi_driver(ds1347_driver); + +MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); +MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); +MODULE_LICENSE("GPL v2"); |