kernel-ark/drivers/rtc/rtc-m41t80.c
David Brownell afe1ab4d57 correct name for rtc-m41t80
The new rtc-m41t80 driver name doesn't match its module name, which
prevents it from properly hotplugging.  Since it's new, no platforms yet
depend on that name ...  so this patch fixes the driver name to match its
module name, rather than going the other way around with a MODULE_ALIAS().

NOTE: This sort of bug is a new thing to watch out for with new-style I2C
drivers; previously I2C couldn't hotplug.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:45 -07:00

918 lines
21 KiB
C

/*
* I2C client/driver for the ST M41T80 family of i2c rtc chips.
*
* Author: Alexander Bigga <ab@mycable.de>
*
* Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
*
* 2006 (c) mycable GmbH
*
* 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/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/i2c.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#ifdef CONFIG_RTC_DRV_M41T80_WDT
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#endif
#define M41T80_REG_SSEC 0
#define M41T80_REG_SEC 1
#define M41T80_REG_MIN 2
#define M41T80_REG_HOUR 3
#define M41T80_REG_WDAY 4
#define M41T80_REG_DAY 5
#define M41T80_REG_MON 6
#define M41T80_REG_YEAR 7
#define M41T80_REG_ALARM_MON 0xa
#define M41T80_REG_ALARM_DAY 0xb
#define M41T80_REG_ALARM_HOUR 0xc
#define M41T80_REG_ALARM_MIN 0xd
#define M41T80_REG_ALARM_SEC 0xe
#define M41T80_REG_FLAGS 0xf
#define M41T80_REG_SQW 0x13
#define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
#define M41T80_ALARM_REG_SIZE \
(M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
#define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */
#define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
#define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
#define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
#define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
#define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
#define M41T80_FEATURE_HT (1 << 0)
#define M41T80_FEATURE_BL (1 << 1)
#define DRV_VERSION "0.05"
struct m41t80_chip_info {
const char *name;
u8 features;
};
static const struct m41t80_chip_info m41t80_chip_info_tbl[] = {
{
.name = "m41t80",
.features = 0,
},
{
.name = "m41t81",
.features = M41T80_FEATURE_HT,
},
{
.name = "m41t81s",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
{
.name = "m41t82",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
{
.name = "m41t83",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
{
.name = "m41st84",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
{
.name = "m41st85",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
{
.name = "m41st87",
.features = M41T80_FEATURE_HT | M41T80_FEATURE_BL,
},
};
struct m41t80_data {
const struct m41t80_chip_info *chip;
struct rtc_device *rtc;
};
static int m41t80_get_datetime(struct i2c_client *client,
struct rtc_time *tm)
{
u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = dt_addr,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
.buf = buf + M41T80_REG_SEC,
},
};
if (i2c_transfer(client->adapter, msgs, 2) < 0) {
dev_err(&client->dev, "read error\n");
return -EIO;
}
tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f);
tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f);
tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f);
tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f);
tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1;
/* assume 20YY not 19YY, and ignore the Century Bit */
tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100;
return 0;
}
/* Sets the given date and time to the real time clock. */
static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
u8 *buf = &wbuf[1];
u8 dt_addr[1] = { M41T80_REG_SEC };
struct i2c_msg msgs_in[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = dt_addr,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
.buf = buf + M41T80_REG_SEC,
},
};
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1 + M41T80_DATETIME_REG_SIZE,
.buf = wbuf,
},
};
/* Read current reg values into buf[1..7] */
if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
dev_err(&client->dev, "read error\n");
return -EIO;
}
wbuf[0] = 0; /* offset into rtc's regs */
/* Merge time-data and register flags into buf[0..7] */
buf[M41T80_REG_SSEC] = 0;
buf[M41T80_REG_SEC] =
BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
buf[M41T80_REG_MIN] =
BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
buf[M41T80_REG_HOUR] =
BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
buf[M41T80_REG_WDAY] =
(tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
buf[M41T80_REG_DAY] =
BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
buf[M41T80_REG_MON] =
BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
/* assume 20YY not 19YY */
buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100);
if (i2c_transfer(client->adapter, msgs, 1) != 1) {
dev_err(&client->dev, "write error\n");
return -EIO;
}
return 0;
}
#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
{
struct i2c_client *client = to_i2c_client(dev);
struct m41t80_data *clientdata = i2c_get_clientdata(client);
u8 reg;
if (clientdata->chip->features & M41T80_FEATURE_BL) {
reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
seq_printf(seq, "battery\t\t: %s\n",
(reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
}
return 0;
}
#else
#define m41t80_rtc_proc NULL
#endif
static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return m41t80_get_datetime(to_i2c_client(dev), tm);
}
static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return m41t80_set_datetime(to_i2c_client(dev), tm);
}
#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
static int
m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = to_i2c_client(dev);
int rc;
switch (cmd) {
case RTC_AIE_OFF:
case RTC_AIE_ON:
break;
default:
return -ENOIOCTLCMD;
}
rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
if (rc < 0)
goto err;
switch (cmd) {
case RTC_AIE_OFF:
rc &= ~M41T80_ALMON_AFE;
break;
case RTC_AIE_ON:
rc |= M41T80_ALMON_AFE;
break;
}
if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
goto err;
return 0;
err:
return -EIO;
}
#else
#define m41t80_rtc_ioctl NULL
#endif
static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
u8 *buf = &wbuf[1];
u8 *reg = buf - M41T80_REG_ALARM_MON;
u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
struct i2c_msg msgs_in[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = dt_addr,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = M41T80_ALARM_REG_SIZE,
.buf = buf,
},
};
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1 + M41T80_ALARM_REG_SIZE,
.buf = wbuf,
},
};
if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
dev_err(&client->dev, "read error\n");
return -EIO;
}
reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
reg[M41T80_REG_ALARM_DAY] = 0;
reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
reg[M41T80_REG_ALARM_MIN] = 0;
reg[M41T80_REG_ALARM_SEC] = 0;
wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
BIN2BCD(t->time.tm_sec) : 0x80;
reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
BIN2BCD(t->time.tm_min) : 0x80;
reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
BIN2BCD(t->time.tm_hour) : 0x80;
reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
BIN2BCD(t->time.tm_mday) : 0x80;
if (t->time.tm_mon >= 0)
reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1);
else
reg[M41T80_REG_ALARM_DAY] |= 0x40;
if (i2c_transfer(client->adapter, msgs, 1) != 1) {
dev_err(&client->dev, "write error\n");
return -EIO;
}
if (t->enabled) {
reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
reg[M41T80_REG_ALARM_MON]) < 0) {
dev_err(&client->dev, "write error\n");
return -EIO;
}
}
return 0;
}
static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
u8 *reg = buf - M41T80_REG_ALARM_MON;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = dt_addr,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = M41T80_ALARM_REG_SIZE + 1,
.buf = buf,
},
};
if (i2c_transfer(client->adapter, msgs, 2) < 0) {
dev_err(&client->dev, "read error\n");
return -EIO;
}
t->time.tm_sec = -1;
t->time.tm_min = -1;
t->time.tm_hour = -1;
t->time.tm_mday = -1;
t->time.tm_mon = -1;
if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f);
if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f);
if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f);
if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
t->time.tm_year = -1;
t->time.tm_wday = -1;
t->time.tm_yday = -1;
t->time.tm_isdst = -1;
t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
return 0;
}
static struct rtc_class_ops m41t80_rtc_ops = {
.read_time = m41t80_rtc_read_time,
.set_time = m41t80_rtc_set_time,
.read_alarm = m41t80_rtc_read_alarm,
.set_alarm = m41t80_rtc_set_alarm,
.proc = m41t80_rtc_proc,
.ioctl = m41t80_rtc_ioctl,
};
#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
static ssize_t m41t80_sysfs_show_flags(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
int val;
val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
if (val < 0)
return -EIO;
return sprintf(buf, "%#x\n", val);
}
static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
int val;
val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
if (val < 0)
return -EIO;
val = (val >> 4) & 0xf;
switch (val) {
case 0:
break;
case 1:
val = 32768;
break;
default:
val = 32768 >> val;
}
return sprintf(buf, "%d\n", val);
}
static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
int almon, sqw;
int val = simple_strtoul(buf, NULL, 0);
if (val) {
if (!is_power_of_2(val))
return -EINVAL;
val = ilog2(val);
if (val == 15)
val = 1;
else if (val < 14)
val = 15 - val;
else
return -EINVAL;
}
/* disable SQW, set SQW frequency & re-enable */
almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
if (almon < 0)
return -EIO;
sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
if (sqw < 0)
return -EIO;
sqw = (sqw & 0x0f) | (val << 4);
if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
almon & ~M41T80_ALMON_SQWE) < 0 ||
i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0)
return -EIO;
if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
almon | M41T80_ALMON_SQWE) < 0)
return -EIO;
return count;
}
static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR,
m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq);
static struct attribute *attrs[] = {
&dev_attr_flags.attr,
&dev_attr_sqwfreq.attr,
NULL,
};
static struct attribute_group attr_group = {
.attrs = attrs,
};
static int m41t80_sysfs_register(struct device *dev)
{
return sysfs_create_group(&dev->kobj, &attr_group);
}
#else
static int m41t80_sysfs_register(struct device *dev)
{
return 0;
}
#endif
#ifdef CONFIG_RTC_DRV_M41T80_WDT
/*
*****************************************************************************
*
* Watchdog Driver
*
*****************************************************************************
*/
static struct i2c_client *save_client;
/* Default margin */
#define WD_TIMO 60 /* 1..31 seconds */
static int wdt_margin = WD_TIMO;
module_param(wdt_margin, int, 0);
MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
static unsigned long wdt_is_open;
static int boot_flag;
/**
* wdt_ping:
*
* Reload counter one with the watchdog timeout. We don't bother reloading
* the cascade counter.
*/
static void wdt_ping(void)
{
unsigned char i2c_data[2];
struct i2c_msg msgs1[1] = {
{
.addr = save_client->addr,
.flags = 0,
.len = 2,
.buf = i2c_data,
},
};
i2c_data[0] = 0x09; /* watchdog register */
if (wdt_margin > 31)
i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
else
/*
* WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
*/
i2c_data[1] = wdt_margin<<2 | 0x82;
i2c_transfer(save_client->adapter, msgs1, 1);
}
/**
* wdt_disable:
*
* disables watchdog.
*/
static void wdt_disable(void)
{
unsigned char i2c_data[2], i2c_buf[0x10];
struct i2c_msg msgs0[2] = {
{
.addr = save_client->addr,
.flags = 0,
.len = 1,
.buf = i2c_data,
},
{
.addr = save_client->addr,
.flags = I2C_M_RD,
.len = 1,
.buf = i2c_buf,
},
};
struct i2c_msg msgs1[1] = {
{
.addr = save_client->addr,
.flags = 0,
.len = 2,
.buf = i2c_data,
},
};
i2c_data[0] = 0x09;
i2c_transfer(save_client->adapter, msgs0, 2);
i2c_data[0] = 0x09;
i2c_data[1] = 0x00;
i2c_transfer(save_client->adapter, msgs1, 1);
}
/**
* wdt_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/* Can't seek (pwrite) on this device
if (ppos != &file->f_pos)
return -ESPIPE;
*/
if (count) {
wdt_ping();
return 1;
}
return 0;
}
static ssize_t wdt_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return 0;
}
/**
* wdt_ioctl:
* @inode: inode of the device
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features. We only actually usefully support
* querying capabilities and current status.
*/
static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_margin, rv;
static struct watchdog_info ident = {
.options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT,
.firmware_version = 1,
.identity = "M41T80 WTD"
};
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info __user *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(boot_flag, (int __user *)arg);
case WDIOC_KEEPALIVE:
wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int __user *)arg))
return -EFAULT;
/* Arbitrary, can't find the card's limits */
if (new_margin < 1 || new_margin > 124)
return -EINVAL;
wdt_margin = new_margin;
wdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(wdt_margin, (int __user *)arg);
case WDIOC_SETOPTIONS:
if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
return -EFAULT;
if (rv & WDIOS_DISABLECARD) {
printk(KERN_INFO
"rtc-m41t80: disable watchdog\n");
wdt_disable();
}
if (rv & WDIOS_ENABLECARD) {
printk(KERN_INFO
"rtc-m41t80: enable watchdog\n");
wdt_ping();
}
return -EINVAL;
}
return -ENOTTY;
}
/**
* wdt_open:
* @inode: inode of device
* @file: file handle to device
*
*/
static int wdt_open(struct inode *inode, struct file *file)
{
if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
if (test_and_set_bit(0, &wdt_is_open))
return -EBUSY;
/*
* Activate
*/
wdt_is_open = 1;
return 0;
}
return -ENODEV;
}
/**
* wdt_close:
* @inode: inode to board
* @file: file handle to board
*
*/
static int wdt_release(struct inode *inode, struct file *file)
{
if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
clear_bit(0, &wdt_is_open);
return 0;
}
/**
* notify_sys:
* @this: our notifier block
* @code: the event being reported
* @unused: unused
*
* Our notifier is called on system shutdowns. We want to turn the card
* off at reboot otherwise the machine will reboot again during memory
* test or worse yet during the following fsck. This would suck, in fact
* trust me - if it happens it does suck.
*/
static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
/* Disable Watchdog */
wdt_disable();
return NOTIFY_DONE;
}
static const struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.read = wdt_read,
.ioctl = wdt_ioctl,
.write = wdt_write,
.open = wdt_open,
.release = wdt_release,
};
static struct miscdevice wdt_dev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt_fops,
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
#endif /* CONFIG_RTC_DRV_M41T80_WDT */
/*
*****************************************************************************
*
* Driver Interface
*
*****************************************************************************
*/
static int m41t80_probe(struct i2c_client *client)
{
int i, rc = 0;
struct rtc_device *rtc = NULL;
struct rtc_time tm;
const struct m41t80_chip_info *chip;
struct m41t80_data *clientdata = NULL;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C
| I2C_FUNC_SMBUS_BYTE_DATA)) {
rc = -ENODEV;
goto exit;
}
dev_info(&client->dev,
"chip found, driver version " DRV_VERSION "\n");
chip = NULL;
for (i = 0; i < ARRAY_SIZE(m41t80_chip_info_tbl); i++) {
if (!strcmp(m41t80_chip_info_tbl[i].name, client->name)) {
chip = &m41t80_chip_info_tbl[i];
break;
}
}
if (!chip) {
dev_err(&client->dev, "%s is not supported\n", client->name);
rc = -ENODEV;
goto exit;
}
clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
if (!clientdata) {
rc = -ENOMEM;
goto exit;
}
rtc = rtc_device_register(client->name, &client->dev,
&m41t80_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
rc = PTR_ERR(rtc);
rtc = NULL;
goto exit;
}
clientdata->rtc = rtc;
clientdata->chip = chip;
i2c_set_clientdata(client, clientdata);
/* Make sure HT (Halt Update) bit is cleared */
rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
if (rc < 0)
goto ht_err;
if (rc & M41T80_ALHOUR_HT) {
if (chip->features & M41T80_FEATURE_HT) {
m41t80_get_datetime(client, &tm);
dev_info(&client->dev, "HT bit was set!\n");
dev_info(&client->dev,
"Power Down at "
"%04i-%02i-%02i %02i:%02i:%02i\n",
tm.tm_year + 1900,
tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
tm.tm_min, tm.tm_sec);
}
if (i2c_smbus_write_byte_data(client,
M41T80_REG_ALARM_HOUR,
rc & ~M41T80_ALHOUR_HT) < 0)
goto ht_err;
}
/* Make sure ST (stop) bit is cleared */
rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC);
if (rc < 0)
goto st_err;
if (rc & M41T80_SEC_ST) {
if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC,
rc & ~M41T80_SEC_ST) < 0)
goto st_err;
}
rc = m41t80_sysfs_register(&client->dev);
if (rc)
goto exit;
#ifdef CONFIG_RTC_DRV_M41T80_WDT
if (chip->features & M41T80_FEATURE_HT) {
rc = misc_register(&wdt_dev);
if (rc)
goto exit;
rc = register_reboot_notifier(&wdt_notifier);
if (rc) {
misc_deregister(&wdt_dev);
goto exit;
}
save_client = client;
}
#endif
return 0;
st_err:
rc = -EIO;
dev_err(&client->dev, "Can't clear ST bit\n");
goto exit;
ht_err:
rc = -EIO;
dev_err(&client->dev, "Can't clear HT bit\n");
goto exit;
exit:
if (rtc)
rtc_device_unregister(rtc);
kfree(clientdata);
return rc;
}
static int m41t80_remove(struct i2c_client *client)
{
struct m41t80_data *clientdata = i2c_get_clientdata(client);
struct rtc_device *rtc = clientdata->rtc;
#ifdef CONFIG_RTC_DRV_M41T80_WDT
if (clientdata->chip->features & M41T80_FEATURE_HT) {
misc_deregister(&wdt_dev);
unregister_reboot_notifier(&wdt_notifier);
}
#endif
if (rtc)
rtc_device_unregister(rtc);
kfree(clientdata);
return 0;
}
static struct i2c_driver m41t80_driver = {
.driver = {
.name = "rtc-m41t80",
},
.probe = m41t80_probe,
.remove = m41t80_remove,
};
static int __init m41t80_rtc_init(void)
{
return i2c_add_driver(&m41t80_driver);
}
static void __exit m41t80_rtc_exit(void)
{
i2c_del_driver(&m41t80_driver);
}
MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>");
MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
module_init(m41t80_rtc_init);
module_exit(m41t80_rtc_exit);