mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 11:19:37 +00:00
![Andrew F. Davis](/assets/img/avatar_default.png)
An spi_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Andrew F. Davis <afd@ti.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Mark Brown <broonie@kernel.org>
185 lines
4.6 KiB
C
185 lines
4.6 KiB
C
/*
|
|
* Driver for Epson RTC-9701JE
|
|
*
|
|
* Copyright (C) 2008 Magnus Damm
|
|
*
|
|
* Based on 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/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)
|
|
{
|
|
int ret;
|
|
unsigned char buf[] = { RSECCNT, RMINCNT, RHRCNT,
|
|
RDAYCNT, RMONCNT, RYRCNT };
|
|
|
|
ret = read_regs(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.
|
|
*/
|
|
|
|
return rtc_valid_tm(dt);
|
|
}
|
|
|
|
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 = ret ? ret : write_reg(dev, RMINCNT, bin2bcd(dt->tm_min));
|
|
ret = ret ? ret : write_reg(dev, RSECCNT, bin2bcd(dt->tm_sec));
|
|
ret = ret ? ret : write_reg(dev, RDAYCNT, bin2bcd(dt->tm_mday));
|
|
ret = ret ? ret : write_reg(dev, RMONCNT, bin2bcd(dt->tm_mon + 1));
|
|
ret = ret ? ret : write_reg(dev, RYRCNT, bin2bcd(dt->tm_year - 100));
|
|
ret = ret ? 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 r9701_probe(struct spi_device *spi)
|
|
{
|
|
struct rtc_device *rtc;
|
|
struct rtc_time dt;
|
|
unsigned char tmp;
|
|
int res;
|
|
|
|
tmp = R100CNT;
|
|
res = read_regs(&spi->dev, &tmp, 1);
|
|
if (res || tmp != 0x20) {
|
|
dev_err(&spi->dev, "cannot read RTC register\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
/*
|
|
* The device seems to be present. Now check if the registers
|
|
* contain invalid values. If so, try to write a default date:
|
|
* 2000/1/1 00:00:00
|
|
*/
|
|
if (r9701_get_datetime(&spi->dev, &dt)) {
|
|
dev_info(&spi->dev, "trying to repair invalid date/time\n");
|
|
dt.tm_sec = 0;
|
|
dt.tm_min = 0;
|
|
dt.tm_hour = 0;
|
|
dt.tm_mday = 1;
|
|
dt.tm_mon = 0;
|
|
dt.tm_year = 100;
|
|
|
|
if (r9701_set_datetime(&spi->dev, &dt) ||
|
|
r9701_get_datetime(&spi->dev, &dt)) {
|
|
dev_err(&spi->dev, "cannot repair RTC register\n");
|
|
return -ENODEV;
|
|
}
|
|
}
|
|
|
|
rtc = devm_rtc_device_register(&spi->dev, "r9701",
|
|
&r9701_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
|
|
spi_set_drvdata(spi, rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int r9701_remove(struct spi_device *spi)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static struct spi_driver r9701_driver = {
|
|
.driver = {
|
|
.name = "rtc-r9701",
|
|
},
|
|
.probe = r9701_probe,
|
|
.remove = r9701_remove,
|
|
};
|
|
|
|
module_spi_driver(r9701_driver);
|
|
|
|
MODULE_DESCRIPTION("r9701 spi RTC driver");
|
|
MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("spi:rtc-r9701");
|