[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/rtc/rtc-m41t80.c b/ap/os/linux/linux-3.4.x/drivers/rtc/rtc-m41t80.c
new file mode 100644
index 0000000..4e0f84a
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/rtc/rtc-m41t80.c
@@ -0,0 +1,908 @@
+/*
+ * 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,
+ /*
+ * XXX - m41t80 alarm functionality is reported broken.
+ * until it is fixed, don't register alarm functions.
+ *
+ .read_alarm = m41t80_rtc_read_alarm,
+ .set_alarm = m41t80_rtc_set_alarm,
+ */
+ .proc = m41t80_rtc_proc,
+ /*
+ * See above comment on broken alarm
+ *
+ .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,
+};
+
+module_i2c_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);