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![John Stultz](/assets/img/avatar_default.png)
The m41t80 driver can read and set the alarm, but it doesn't seem to have a functional alarm irq. This causes failures when the generic core sees alarm functions, but then cannot use them properly for things like UIE mode. Disabling the alarm functions allows proper error reporting, and possible fallback to emulated modes. Once someone fixes the alarm irq functionality, this can be restored. CC: stable@kernel.org CC: Matt Turner <mattst88@gmail.com> CC: Nico Macrionitis <acrux@cruxppc.org> CC: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Reported-by: Matt Turner <mattst88@gmail.com> Reported-by: Nico Macrionitis <acrux@cruxppc.org> Tested-by: Nico Macrionitis <acrux@cruxppc.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
919 lines
23 KiB
C
919 lines
23 KiB
C
/*
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* I2C client/driver for the ST M41T80 family of i2c rtc chips.
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*
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* Author: Alexander Bigga <ab@mycable.de>
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*
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* Based on m41t00.c by Mark A. Greer <mgreer@mvista.com>
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*
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* 2006 (c) mycable GmbH
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/bcd.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rtc.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/string.h>
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#ifdef CONFIG_RTC_DRV_M41T80_WDT
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#include <linux/fs.h>
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#include <linux/ioctl.h>
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#include <linux/miscdevice.h>
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#include <linux/reboot.h>
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#include <linux/watchdog.h>
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#endif
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#define M41T80_REG_SSEC 0
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#define M41T80_REG_SEC 1
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#define M41T80_REG_MIN 2
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#define M41T80_REG_HOUR 3
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#define M41T80_REG_WDAY 4
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#define M41T80_REG_DAY 5
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#define M41T80_REG_MON 6
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#define M41T80_REG_YEAR 7
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#define M41T80_REG_ALARM_MON 0xa
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#define M41T80_REG_ALARM_DAY 0xb
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#define M41T80_REG_ALARM_HOUR 0xc
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#define M41T80_REG_ALARM_MIN 0xd
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#define M41T80_REG_ALARM_SEC 0xe
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#define M41T80_REG_FLAGS 0xf
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#define M41T80_REG_SQW 0x13
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#define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1)
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#define M41T80_ALARM_REG_SIZE \
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(M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON)
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#define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */
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#define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
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#define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
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#define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
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#define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
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#define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
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#define M41T80_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */
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#define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */
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#define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */
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#define M41T80_FEATURE_HT (1 << 0) /* Halt feature */
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#define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */
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#define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */
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#define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */
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#define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */
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#define DRV_VERSION "0.05"
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static DEFINE_MUTEX(m41t80_rtc_mutex);
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static const struct i2c_device_id m41t80_id[] = {
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{ "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
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{ "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
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{ "m41t80", M41T80_FEATURE_SQ },
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{ "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
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{ "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, m41t80_id);
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struct m41t80_data {
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u8 features;
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struct rtc_device *rtc;
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};
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static int m41t80_get_datetime(struct i2c_client *client,
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struct rtc_time *tm)
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{
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u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC };
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = dt_addr,
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},
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
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.buf = buf + M41T80_REG_SEC,
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},
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};
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if (i2c_transfer(client->adapter, msgs, 2) < 0) {
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dev_err(&client->dev, "read error\n");
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return -EIO;
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}
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tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f);
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tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f);
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tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f);
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tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f);
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tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07;
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tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1;
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/* assume 20YY not 19YY, and ignore the Century Bit */
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tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100;
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return rtc_valid_tm(tm);
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}
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/* Sets the given date and time to the real time clock. */
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static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
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{
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u8 wbuf[1 + M41T80_DATETIME_REG_SIZE];
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u8 *buf = &wbuf[1];
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u8 dt_addr[1] = { M41T80_REG_SEC };
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struct i2c_msg msgs_in[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = dt_addr,
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},
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC,
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.buf = buf + M41T80_REG_SEC,
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},
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};
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1 + M41T80_DATETIME_REG_SIZE,
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.buf = wbuf,
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},
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};
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/* Read current reg values into buf[1..7] */
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if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
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dev_err(&client->dev, "read error\n");
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return -EIO;
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}
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wbuf[0] = 0; /* offset into rtc's regs */
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/* Merge time-data and register flags into buf[0..7] */
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buf[M41T80_REG_SSEC] = 0;
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buf[M41T80_REG_SEC] =
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bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f);
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buf[M41T80_REG_MIN] =
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bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f);
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buf[M41T80_REG_HOUR] =
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bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ;
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buf[M41T80_REG_WDAY] =
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(tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07);
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buf[M41T80_REG_DAY] =
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bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
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buf[M41T80_REG_MON] =
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bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
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/* assume 20YY not 19YY */
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buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
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if (i2c_transfer(client->adapter, msgs, 1) != 1) {
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dev_err(&client->dev, "write error\n");
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return -EIO;
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}
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return 0;
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}
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#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
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static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct m41t80_data *clientdata = i2c_get_clientdata(client);
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u8 reg;
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if (clientdata->features & M41T80_FEATURE_BL) {
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reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
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seq_printf(seq, "battery\t\t: %s\n",
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(reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok");
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}
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return 0;
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}
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#else
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#define m41t80_rtc_proc NULL
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#endif
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static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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return m41t80_get_datetime(to_i2c_client(dev), tm);
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}
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static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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return m41t80_set_datetime(to_i2c_client(dev), tm);
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}
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static int m41t80_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct i2c_client *client = to_i2c_client(dev);
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int rc;
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rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
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if (rc < 0)
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goto err;
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if (enabled)
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rc |= M41T80_ALMON_AFE;
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else
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rc &= ~M41T80_ALMON_AFE;
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if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0)
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goto err;
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return 0;
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err:
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return -EIO;
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}
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static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
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struct i2c_client *client = to_i2c_client(dev);
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u8 wbuf[1 + M41T80_ALARM_REG_SIZE];
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u8 *buf = &wbuf[1];
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u8 *reg = buf - M41T80_REG_ALARM_MON;
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u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
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struct i2c_msg msgs_in[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = dt_addr,
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},
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = M41T80_ALARM_REG_SIZE,
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.buf = buf,
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},
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};
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1 + M41T80_ALARM_REG_SIZE,
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.buf = wbuf,
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},
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};
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if (i2c_transfer(client->adapter, msgs_in, 2) < 0) {
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dev_err(&client->dev, "read error\n");
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return -EIO;
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}
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reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE);
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reg[M41T80_REG_ALARM_DAY] = 0;
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reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80);
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reg[M41T80_REG_ALARM_MIN] = 0;
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reg[M41T80_REG_ALARM_SEC] = 0;
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wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */
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reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ?
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bin2bcd(t->time.tm_sec) : 0x80;
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reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ?
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bin2bcd(t->time.tm_min) : 0x80;
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reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ?
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bin2bcd(t->time.tm_hour) : 0x80;
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reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ?
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bin2bcd(t->time.tm_mday) : 0x80;
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if (t->time.tm_mon >= 0)
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reg[M41T80_REG_ALARM_MON] |= bin2bcd(t->time.tm_mon + 1);
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else
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reg[M41T80_REG_ALARM_DAY] |= 0x40;
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if (i2c_transfer(client->adapter, msgs, 1) != 1) {
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dev_err(&client->dev, "write error\n");
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return -EIO;
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}
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if (t->enabled) {
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reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE;
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if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
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reg[M41T80_REG_ALARM_MON]) < 0) {
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dev_err(&client->dev, "write error\n");
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return -EIO;
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}
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}
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return 0;
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}
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static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
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struct i2c_client *client = to_i2c_client(dev);
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u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */
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u8 dt_addr[1] = { M41T80_REG_ALARM_MON };
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u8 *reg = buf - M41T80_REG_ALARM_MON;
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struct i2c_msg msgs[] = {
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{
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.addr = client->addr,
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.flags = 0,
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.len = 1,
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.buf = dt_addr,
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},
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{
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.addr = client->addr,
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.flags = I2C_M_RD,
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.len = M41T80_ALARM_REG_SIZE + 1,
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.buf = buf,
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},
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};
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if (i2c_transfer(client->adapter, msgs, 2) < 0) {
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dev_err(&client->dev, "read error\n");
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return -EIO;
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}
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t->time.tm_sec = -1;
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t->time.tm_min = -1;
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t->time.tm_hour = -1;
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t->time.tm_mday = -1;
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t->time.tm_mon = -1;
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if (!(reg[M41T80_REG_ALARM_SEC] & 0x80))
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t->time.tm_sec = bcd2bin(reg[M41T80_REG_ALARM_SEC] & 0x7f);
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if (!(reg[M41T80_REG_ALARM_MIN] & 0x80))
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t->time.tm_min = bcd2bin(reg[M41T80_REG_ALARM_MIN] & 0x7f);
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if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80))
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t->time.tm_hour = bcd2bin(reg[M41T80_REG_ALARM_HOUR] & 0x3f);
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if (!(reg[M41T80_REG_ALARM_DAY] & 0x80))
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t->time.tm_mday = bcd2bin(reg[M41T80_REG_ALARM_DAY] & 0x3f);
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if (!(reg[M41T80_REG_ALARM_DAY] & 0x40))
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t->time.tm_mon = bcd2bin(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1;
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t->time.tm_year = -1;
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t->time.tm_wday = -1;
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t->time.tm_yday = -1;
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t->time.tm_isdst = -1;
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t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE);
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t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF);
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return 0;
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}
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static struct rtc_class_ops m41t80_rtc_ops = {
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.read_time = m41t80_rtc_read_time,
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.set_time = m41t80_rtc_set_time,
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/*
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* XXX - m41t80 alarm functionality is reported broken.
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* until it is fixed, don't register alarm functions.
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*
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.read_alarm = m41t80_rtc_read_alarm,
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.set_alarm = m41t80_rtc_set_alarm,
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*/
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.proc = m41t80_rtc_proc,
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/*
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* See above comment on broken alarm
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*
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.alarm_irq_enable = m41t80_rtc_alarm_irq_enable,
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*/
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};
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#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
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static ssize_t m41t80_sysfs_show_flags(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct i2c_client *client = to_i2c_client(dev);
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int val;
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val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
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if (val < 0)
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return -EIO;
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return sprintf(buf, "%#x\n", val);
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}
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static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL);
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static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct m41t80_data *clientdata = i2c_get_clientdata(client);
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int val, reg_sqw;
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|
|
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);
|