Commit 2805b969 authored by Magnus Damm's avatar Magnus Damm Committed by Linus Torvalds

rtc: add support for Epson RTC-9701JE V2

Add support for the Epson RTC-9701JE SPI RTC device.
Signed-off-by: default avatarMagnus Damm <damm@igel.co.jp>
Acked-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Acked-by: default avatarDavid Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 102f4a02
......@@ -265,6 +265,15 @@ config RTC_DRV_MAX6902
This driver can also be built as a module. If so, the module
will be called rtc-max6902.
config RTC_DRV_R9701
tristate "Epson RTC-9701JE"
help
If you say yes here you will get support for the
Epson RTC-9701JE SPI RTC chip.
This driver can also be built as a module. If so, the module
will be called rtc-r9701.
config RTC_DRV_RS5C348
tristate "Ricoh RS5C348A/B"
help
......
......@@ -40,6 +40,7 @@ obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o
obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
obj-$(CONFIG_RTC_DRV_PCF8583) += rtc-pcf8583.o
obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o
obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o
obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o
obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
......
/* drivers/rtc/rtc-r9701.c
*
* Driver for Epson RTC-9701JE
*
* Copyright (C) 2008 Magnus Damm
*
* Based on drivers/rtc/rtc-max6902.c
*
* Copyright (C) 2006 8D Technologies inc.
* Copyright (C) 2004 Compulab Ltd.
*
* 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/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#define RSECCNT 0x00 /* Second Counter */
#define RMINCNT 0x01 /* Minute Counter */
#define RHRCNT 0x02 /* Hour Counter */
#define RWKCNT 0x03 /* Week Counter */
#define RDAYCNT 0x04 /* Day Counter */
#define RMONCNT 0x05 /* Month Counter */
#define RYRCNT 0x06 /* Year Counter */
#define R100CNT 0x07 /* Y100 Counter */
#define RMINAR 0x08 /* Minute Alarm */
#define RHRAR 0x09 /* Hour Alarm */
#define RWKAR 0x0a /* Week/Day Alarm */
#define RTIMCNT 0x0c /* Interval Timer */
#define REXT 0x0d /* Extension Register */
#define RFLAG 0x0e /* RTC Flag Register */
#define RCR 0x0f /* RTC Control Register */
static int write_reg(struct device *dev, int 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(spi, buf, ARRAY_SIZE(buf));
}
static int read_regs(struct device *dev, unsigned char *regs, int no_regs)
{
struct spi_device *spi = to_spi_device(dev);
u8 txbuf[1], rxbuf[1];
int k, ret;
ret = 0;
for (k = 0; ret == 0 && k < no_regs; k++) {
txbuf[0] = 0x80 | regs[k];
ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1);
regs[k] = rxbuf[0];
}
return ret;
}
static int r9701_get_datetime(struct device *dev, struct rtc_time *dt)
{
struct spi_device *spi = to_spi_device(dev);
unsigned long time;
int ret;
unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
RDAYCNT, RMONCNT, RYRCNT };
ret = read_regs(&spi->dev, buf, ARRAY_SIZE(buf));
if (ret)
return ret;
memset(dt, 0, sizeof(*dt));
dt->tm_sec = BCD2BIN(buf[0]); /* RSECCNT */
dt->tm_min = BCD2BIN(buf[1]); /* RMINCNT */
dt->tm_hour = BCD2BIN(buf[2]); /* RHRCNT */
dt->tm_mday = BCD2BIN(buf[3]); /* RDAYCNT */
dt->tm_mon = BCD2BIN(buf[4]) - 1; /* RMONCNT */
dt->tm_year = BCD2BIN(buf[5]) + 100; /* RYRCNT */
/* the rtc device may contain illegal values on power up
* according to the data sheet. make sure they are valid.
*/
ret = rtc_valid_tm(dt);
if (ret)
return ret;
/* don't bother with yday, wday and isdst.
* let the rtc core calculate them for us.
*/
rtc_tm_to_time(dt, &time);
rtc_time_to_tm(time, dt);
return 0;
}
static int r9701_set_datetime(struct device *dev, struct rtc_time *dt)
{
int ret, year;
year = dt->tm_year + 1900;
if (year >= 2100 || year < 2000)
return -EINVAL;
ret = write_reg(dev, RHRCNT, BIN2BCD(dt->tm_hour));
ret |= write_reg(dev, RMINCNT, BIN2BCD(dt->tm_min));
ret |= write_reg(dev, RSECCNT, BIN2BCD(dt->tm_sec));
ret |= write_reg(dev, RDAYCNT, BIN2BCD(dt->tm_mday));
ret |= write_reg(dev, RMONCNT, BIN2BCD(dt->tm_mon + 1));
ret |= write_reg(dev, RYRCNT, BIN2BCD(dt->tm_year - 100));
ret |= write_reg(dev, RWKCNT, 1 << dt->tm_wday);
return ret;
}
static const struct rtc_class_ops r9701_rtc_ops = {
.read_time = r9701_get_datetime,
.set_time = r9701_set_datetime,
};
static int __devinit r9701_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
unsigned char tmp;
int res;
rtc = rtc_device_register("r9701",
&spi->dev, &r9701_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
dev_set_drvdata(&spi->dev, rtc);
spi->mode = SPI_MODE_3;
spi->bits_per_word = 8;
spi_setup(spi);
tmp = R100CNT;
res = read_regs(&spi->dev, &tmp, 1);
if (res || tmp != 0x20) {
rtc_device_unregister(rtc);
return res;
}
return 0;
}
static int __devexit r9701_remove(struct spi_device *spi)
{
struct rtc_device *rtc = dev_get_drvdata(&spi->dev);
rtc_device_unregister(rtc);
return 0;
}
static struct spi_driver r9701_driver = {
.driver = {
.name = "rtc-r9701",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = r9701_probe,
.remove = __devexit_p(r9701_remove),
};
static __init int r9701_init(void)
{
return spi_register_driver(&r9701_driver);
}
module_init(r9701_init);
static __exit void r9701_exit(void)
{
spi_unregister_driver(&r9701_driver);
}
module_exit(r9701_exit);
MODULE_DESCRIPTION("r9701 spi RTC driver");
MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
MODULE_LICENSE("GPL");
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