mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![John Stultz](/assets/img/avatar_default.png)
Commit f44f7f96a2
("RTC: Initialize kernel state from RTC") uncovered
an issue in a number of RTC drivers, where the drivers call
rtc_device_register before initializing the clientdata.
This frequently results in null pointer dereferences when the
rtc_device_register immediately makes use of the rtc device, calling
rtc_read_alarm.
The solution is to ensure the clientdata is initialized prior to registering
the rtc device.
CC: Wolfram Sang <w.sang@pengutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
910 lines
22 KiB
C
910 lines
22 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/bcd.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/string.h>
|
|
#ifdef CONFIG_RTC_DRV_M41T80_WDT
|
|
#include <linux/fs.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/watchdog.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_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */
|
|
#define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */
|
|
#define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */
|
|
|
|
#define M41T80_FEATURE_HT (1 << 0) /* Halt feature */
|
|
#define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */
|
|
#define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */
|
|
#define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */
|
|
#define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */
|
|
|
|
#define DRV_VERSION "0.05"
|
|
|
|
static DEFINE_MUTEX(m41t80_rtc_mutex);
|
|
static const struct i2c_device_id m41t80_id[] = {
|
|
{ "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
|
|
{ "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
|
|
{ "m41t80", M41T80_FEATURE_SQ },
|
|
{ "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
|
|
{ "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, m41t80_id);
|
|
|
|
struct m41t80_data {
|
|
u8 features;
|
|
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 rtc_valid_tm(tm);
|
|
}
|
|
|
|
/* 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->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);
|
|
}
|
|
|
|
static int m41t80_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int rc;
|
|
|
|
rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
|
|
if (rc < 0)
|
|
goto err;
|
|
|
|
if (enabled)
|
|
rc |= M41T80_ALMON_AFE;
|
|
else
|
|
rc &= ~M41T80_ALMON_AFE;
|
|
|
|
if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
|
|
goto err;
|
|
|
|
return 0;
|
|
err:
|
|
return -EIO;
|
|
}
|
|
|
|
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,
|
|
.alarm_irq_enable = m41t80_rtc_alarm_irq_enable,
|
|
};
|
|
|
|
#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);
|
|
struct m41t80_data *clientdata = i2c_get_clientdata(client);
|
|
int val, reg_sqw;
|
|
|
|
if (!(clientdata->features & M41T80_FEATURE_SQ))
|
|
return -EINVAL;
|
|
|
|
reg_sqw = M41T80_REG_SQW;
|
|
if (clientdata->features & M41T80_FEATURE_SQ_ALT)
|
|
reg_sqw = M41T80_REG_WDAY;
|
|
val = i2c_smbus_read_byte_data(client, 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);
|
|
struct m41t80_data *clientdata = i2c_get_clientdata(client);
|
|
int almon, sqw, reg_sqw;
|
|
int val = simple_strtoul(buf, NULL, 0);
|
|
|
|
if (!(clientdata->features & M41T80_FEATURE_SQ))
|
|
return -EINVAL;
|
|
|
|
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;
|
|
reg_sqw = M41T80_REG_SQW;
|
|
if (clientdata->features & M41T80_FEATURE_SQ_ALT)
|
|
reg_sqw = M41T80_REG_WDAY;
|
|
sqw = i2c_smbus_read_byte_data(client, 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, 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,
|
|
},
|
|
};
|
|
struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
|
|
|
|
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;
|
|
|
|
/*
|
|
* M41T65 has three bits for watchdog resolution. Don't set bit 7, as
|
|
* that would be an invalid resolution.
|
|
*/
|
|
if (clientdata->features & M41T80_FEATURE_WD)
|
|
i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
|
|
|
|
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)
|
|
{
|
|
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 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) {
|
|
pr_info("rtc-m41t80: disable watchdog\n");
|
|
wdt_disable();
|
|
}
|
|
|
|
if (rv & WDIOS_ENABLECARD) {
|
|
pr_info("rtc-m41t80: enable watchdog\n");
|
|
wdt_ping();
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
return -ENOTTY;
|
|
}
|
|
|
|
static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&m41t80_rtc_mutex);
|
|
ret = wdt_ioctl(file, cmd, arg);
|
|
mutex_unlock(&m41t80_rtc_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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) {
|
|
mutex_lock(&m41t80_rtc_mutex);
|
|
if (test_and_set_bit(0, &wdt_is_open)) {
|
|
mutex_unlock(&m41t80_rtc_mutex);
|
|
return -EBUSY;
|
|
}
|
|
/*
|
|
* Activate
|
|
*/
|
|
wdt_is_open = 1;
|
|
mutex_unlock(&m41t80_rtc_mutex);
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
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,
|
|
.unlocked_ioctl = wdt_unlocked_ioctl,
|
|
.write = wdt_write,
|
|
.open = wdt_open,
|
|
.release = wdt_release,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
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,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
int rc = 0;
|
|
struct rtc_device *rtc = NULL;
|
|
struct rtc_time tm;
|
|
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");
|
|
|
|
clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL);
|
|
if (!clientdata) {
|
|
rc = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
|
|
clientdata->features = id->driver_data;
|
|
i2c_set_clientdata(client, clientdata);
|
|
|
|
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;
|
|
|
|
/* 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 (clientdata->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 (clientdata->features & M41T80_FEATURE_HT) {
|
|
save_client = client;
|
|
rc = misc_register(&wdt_dev);
|
|
if (rc)
|
|
goto exit;
|
|
rc = register_reboot_notifier(&wdt_notifier);
|
|
if (rc) {
|
|
misc_deregister(&wdt_dev);
|
|
goto exit;
|
|
}
|
|
}
|
|
#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->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,
|
|
.id_table = m41t80_id,
|
|
};
|
|
|
|
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);
|