diff options
| -rw-r--r-- | drivers/hwmon/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/hwmon/w83793.c | 482 |
2 files changed, 481 insertions, 4 deletions
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 9234c2e2c7d9..cdfb0637f247 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -910,7 +910,8 @@ config SENSORS_W83793 select HWMON_VID help If you say yes here you get support for the Winbond W83793 - hardware monitoring chip. + hardware monitoring chip, including support for the integrated + watchdog. This driver can also be built as a module. If so, the module will be called w83793. diff --git a/drivers/hwmon/w83793.c b/drivers/hwmon/w83793.c index 9a2022b67495..9de81a4c15a2 100644 --- a/drivers/hwmon/w83793.c +++ b/drivers/hwmon/w83793.c @@ -3,6 +3,10 @@ Copyright (C) 2006 Winbond Electronics Corp. Yuan Mu Rudolf Marek <r.marek@assembler.cz> + Copyright (C) 2009-2010 Sven Anders <anders@anduras.de>, ANDURAS AG. + Watchdog driver part + (Based partially on fschmd driver, + Copyright 2007-2008 by Hans de Goede) This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -35,6 +39,16 @@ #include <linux/hwmon-sysfs.h> #include <linux/err.h> #include <linux/mutex.h> +#include <linux/fs.h> +#include <linux/watchdog.h> +#include <linux/miscdevice.h> +#include <linux/uaccess.h> +#include <linux/kref.h> +#include <linux/notifier.h> +#include <linux/reboot.h> + +/* Default values */ +#define WATCHDOG_TIMEOUT 2 /* 2 minute default timeout */ /* Addresses to scan */ static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, 0x2f, @@ -51,6 +65,18 @@ static int reset; module_param(reset, bool, 0); MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended"); +static int timeout = WATCHDOG_TIMEOUT; /* default timeout in minutes */ +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, + "Watchdog timeout in minutes. 2<= timeout <=255 (default=" + __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + /* Address 0x00, 0x0d, 0x0e, 0x0f in all three banks are reserved as ID, Bank Select registers @@ -72,6 +98,11 @@ MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended"); #define W83793_REG_VID_LATCHB 0x08 #define W83793_REG_VID_CTRL 0x59 +#define W83793_REG_WDT_LOCK 0x01 +#define W83793_REG_WDT_ENABLE 0x02 +#define W83793_REG_WDT_STATUS 0x03 +#define W83793_REG_WDT_TIMEOUT 0x04 + static u16 W83793_REG_TEMP_MODE[2] = { 0x5e, 0x5f }; #define TEMP_READ 0 @@ -223,8 +254,37 @@ struct w83793_data { u8 tolerance[3]; /* Temp tolerance(Smart Fan I/II) */ u8 sf2_pwm[6][7]; /* Smart FanII: Fan duty cycle */ u8 sf2_temp[6][7]; /* Smart FanII: Temp level point */ + + /* watchdog */ + struct i2c_client *client; + struct mutex watchdog_lock; + struct list_head list; /* member of the watchdog_data_list */ + struct kref kref; + struct miscdevice watchdog_miscdev; + unsigned long watchdog_is_open; + char watchdog_expect_close; + char watchdog_name[10]; /* must be unique to avoid sysfs conflict */ + unsigned int watchdog_caused_reboot; + int watchdog_timeout; /* watchdog timeout in minutes */ }; +/* Somewhat ugly :( global data pointer list with all devices, so that + we can find our device data as when using misc_register. There is no + other method to get to one's device data from the open file-op and + for usage in the reboot notifier callback. */ +static LIST_HEAD(watchdog_data_list); + +/* Note this lock not only protect list access, but also data.kref access */ +static DEFINE_MUTEX(watchdog_data_mutex); + +/* Release our data struct when we're detached from the i2c client *and* all + references to our watchdog device are released */ +static void w83793_release_resources(struct kref *ref) +{ + struct w83793_data *data = container_of(ref, struct w83793_data, kref); + kfree(data); +} + static u8 w83793_read_value(struct i2c_client *client, u16 reg); static int w83793_write_value(struct i2c_client *client, u16 reg, u8 value); static int w83793_probe(struct i2c_client *client, @@ -1063,14 +1123,349 @@ static void w83793_init_client(struct i2c_client *client) /* Start monitoring */ w83793_write_value(client, W83793_REG_CONFIG, w83793_read_value(client, W83793_REG_CONFIG) | 0x01); +} + +/* + * Watchdog routines + */ + +static int watchdog_set_timeout(struct w83793_data *data, int timeout) +{ + int ret, mtimeout; + + mtimeout = DIV_ROUND_UP(timeout, 60); + + if (mtimeout > 255) + return -EINVAL; + + mutex_lock(&data->watchdog_lock); + if (!data->client) { + ret = -ENODEV; + goto leave; + } + + data->watchdog_timeout = mtimeout; + + /* Set Timeout value (in Minutes) */ + w83793_write_value(data->client, W83793_REG_WDT_TIMEOUT, + data->watchdog_timeout); + + ret = mtimeout * 60; + +leave: + mutex_unlock(&data->watchdog_lock); + return ret; +} + +static int watchdog_get_timeout(struct w83793_data *data) +{ + int timeout; + + mutex_lock(&data->watchdog_lock); + timeout = data->watchdog_timeout * 60; + mutex_unlock(&data->watchdog_lock); + + return timeout; +} + +static int watchdog_trigger(struct w83793_data *data) +{ + int ret = 0; + + mutex_lock(&data->watchdog_lock); + if (!data->client) { + ret = -ENODEV; + goto leave; + } + + /* Set Timeout value (in Minutes) */ + w83793_write_value(data->client, W83793_REG_WDT_TIMEOUT, + data->watchdog_timeout); + +leave: + mutex_unlock(&data->watchdog_lock); + return ret; +} + +static int watchdog_enable(struct w83793_data *data) +{ + int ret = 0; + + mutex_lock(&data->watchdog_lock); + if (!data->client) { + ret = -ENODEV; + goto leave; + } + + /* Set initial timeout */ + w83793_write_value(data->client, W83793_REG_WDT_TIMEOUT, + data->watchdog_timeout); + + /* Enable Soft Watchdog */ + w83793_write_value(data->client, W83793_REG_WDT_LOCK, 0x55); + +leave: + mutex_unlock(&data->watchdog_lock); + return ret; +} + +static int watchdog_disable(struct w83793_data *data) +{ + int ret = 0; + + mutex_lock(&data->watchdog_lock); + if (!data->client) { + ret = -ENODEV; + goto leave; + } + + /* Disable Soft Watchdog */ + w83793_write_value(data->client, W83793_REG_WDT_LOCK, 0xAA); + +leave: + mutex_unlock(&data->watchdog_lock); + return ret; +} + +static int watchdog_open(struct inode *inode, struct file *filp) +{ + struct w83793_data *pos, *data = NULL; + int watchdog_is_open; + + /* We get called from drivers/char/misc.c with misc_mtx hold, and we + call misc_register() from w83793_probe() with watchdog_data_mutex + hold, as misc_register() takes the misc_mtx lock, this is a possible + deadlock, so we use mutex_trylock here. */ + if (!mutex_trylock(&watchdog_data_mutex)) + return -ERESTARTSYS; + list_for_each_entry(pos, &watchdog_data_list, list) { + if (pos->watchdog_miscdev.minor == iminor(inode)) { + data = pos; + break; + } + } + + /* Check, if device is already open */ + watchdog_is_open = test_and_set_bit(0, &data->watchdog_is_open); + + /* Increase data reference counter (if not already done). + Note we can never not have found data, so we don't check for this */ + if (!watchdog_is_open) + kref_get(&data->kref); + + mutex_unlock(&watchdog_data_mutex); + + /* Check, if device is already open and possibly issue error */ + if (watchdog_is_open) + return -EBUSY; + + /* Enable Soft Watchdog */ + watchdog_enable(data); + + /* Store pointer to data into filp's private data */ + filp->private_data = data; + + return nonseekable_open(inode, filp); +} + +static int watchdog_close(struct inode *inode, struct file *filp) +{ + struct w83793_data *data = filp->private_data; + if (data->watchdog_expect_close) { + watchdog_disable(data); + data->watchdog_expect_close = 0; + } else { + watchdog_trigger(data); + dev_crit(&data->client->dev, + "unexpected close, not stopping watchdog!\n"); + } + + clear_bit(0, &data->watchdog_is_open); + + /* Decrease data reference counter */ + mutex_lock(&watchdog_data_mutex); + kref_put(&data->kref, w83793_release_resources); + mutex_unlock(&watchdog_data_mutex); + + return 0; +} + +static ssize_t watchdog_write(struct file *filp, const char __user *buf, + size_t count, loff_t *offset) +{ + size_t ret; + struct w83793_data *data = filp->private_data; + + if (count) { + if (!nowayout) { + size_t i; + + /* Clear it in case it was set with a previous write */ + data->watchdog_expect_close = 0; + + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + data->watchdog_expect_close = 1; + } + } + ret = watchdog_trigger(data); + if (ret < 0) + return ret; + } + return count; +} + +static int watchdog_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + static struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | + WDIOF_SETTIMEOUT | + WDIOF_CARDRESET, + .identity = "w83793 watchdog" + }; + + int val, ret = 0; + struct w83793_data *data = filp->private_data; + + switch (cmd) { + case WDIOC_GETSUPPORT: + if (!nowayout) + ident.options |= WDIOF_MAGICCLOSE; + if (copy_to_user((void __user *)arg, &ident, sizeof(ident))) + ret = -EFAULT; + break; + + case WDIOC_GETSTATUS: + val = data->watchdog_caused_reboot ? WDIOF_CARDRESET : 0; + ret = put_user(val, (int __user *)arg); + break; + + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, (int __user *)arg); + break; + + case WDIOC_KEEPALIVE: + ret = watchdog_trigger(data); + break; + + case WDIOC_GETTIMEOUT: + val = watchdog_get_timeout(data); + ret = put_user(val, (int __user *)arg); + break; + + case WDIOC_SETTIMEOUT: + if (get_user(val, (int __user *)arg)) { + ret = -EFAULT; + break; + } + ret = watchdog_set_timeout(data, val); + if (ret > 0) + ret = put_user(ret, (int __user *)arg); + break; + + case WDIOC_SETOPTIONS: + if (get_user(val, (int __user *)arg)) { + ret = -EFAULT; + break; + } + + if (val & WDIOS_DISABLECARD) + ret = watchdog_disable(data); + else if (val & WDIOS_ENABLECARD) + ret = watchdog_enable(data); + else + ret = -EINVAL; + + break; + default: + ret = -ENOTTY; + } + + return ret; +} + +static const struct file_operations watchdog_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = watchdog_open, + .release = watchdog_close, + .write = watchdog_write, + .ioctl = watchdog_ioctl, +}; + +/* + * Notifier for system down + */ + +static int watchdog_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + struct w83793_data *data = NULL; + + if (code == SYS_DOWN || code == SYS_HALT) { + + /* Disable each registered watchdog */ + mutex_lock(&watchdog_data_mutex); + list_for_each_entry(data, &watchdog_data_list, list) { + if (data->watchdog_miscdev.minor) + watchdog_disable(data); + } + mutex_unlock(&watchdog_data_mutex); + } + + return NOTIFY_DONE; } +/* + * The WDT needs to learn about soft shutdowns in order to + * turn the timebomb registers off. + */ + +static struct notifier_block watchdog_notifier = { + .notifier_call = watchdog_notify_sys, +}; + +/* + * Init / remove routines + */ + static int w83793_remove(struct i2c_client *client) { struct w83793_data *data = i2c_get_clientdata(client); struct device *dev = &client->dev; - int i; + int i, tmp; + + /* Unregister the watchdog (if registered) */ + if (data->watchdog_miscdev.minor) { + misc_deregister(&data->watchdog_miscdev); + + if (data->watchdog_is_open) { + dev_warn(&client->dev, + "i2c client detached with watchdog open! " + "Stopping watchdog.\n"); + watchdog_disable(data); + } + + mutex_lock(&watchdog_data_mutex); + list_del(&data->list); + mutex_unlock(&watchdog_data_mutex); + + /* Tell the watchdog code the client is gone */ + mutex_lock(&data->watchdog_lock); + data->client = NULL; + mutex_unlock(&data->watchdog_lock); + } + + /* Reset Configuration Register to Disable Watch Dog Registers */ + tmp = w83793_read_value(client, W83793_REG_CONFIG); + w83793_write_value(client, W83793_REG_CONFIG, tmp & ~0x04); + + unregister_reboot_notifier(&watchdog_notifier); hwmon_device_unregister(data->hwmon_dev); @@ -1099,7 +1494,10 @@ static int w83793_remove(struct i2c_client *client) if (data->lm75[1] != NULL) i2c_unregister_device(data->lm75[1]); - kfree(data); + /* Decrease data reference counter */ + mutex_lock(&watchdog_data_mutex); + kref_put(&data->kref, w83793_release_resources); + mutex_unlock(&watchdog_data_mutex); return 0; } @@ -1203,6 +1601,7 @@ static int w83793_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; + const int watchdog_minors[] = { WATCHDOG_MINOR, 212, 213, 214, 215 }; struct w83793_data *data; int i, tmp, val, err; int files_fan = ARRAY_SIZE(w83793_left_fan) / 7; @@ -1218,6 +1617,14 @@ static int w83793_probe(struct i2c_client *client, i2c_set_clientdata(client, data); data->bank = i2c_smbus_read_byte_data(client, W83793_REG_BANKSEL); mutex_init(&data->update_lock); + mutex_init(&data->watchdog_lock); + INIT_LIST_HEAD(&data->list); + kref_init(&data->kref); + + /* Store client pointer in our data struct for watchdog usage + (where the client is found through a data ptr instead of the + otherway around) */ + data->client = client; err = w83793_detect_subclients(client); if (err) @@ -1380,8 +1787,77 @@ static int w83793_probe(struct i2c_client *client, goto exit_remove; } + /* Watchdog initialization */ + + /* Register boot notifier */ + err = register_reboot_notifier(&watchdog_notifier); + if (err != 0) { + dev_err(&client->dev, + "cannot register reboot notifier (err=%d)\n", err); + goto exit_devunreg; + } + + /* Enable Watchdog registers. + Set Configuration Register to Enable Watch Dog Registers + (Bit 2) = XXXX, X1XX. */ + tmp = w83793_read_value(client, W83793_REG_CONFIG); + w83793_write_value(client, W83793_REG_CONFIG, tmp | 0x04); + + /* Set the default watchdog timeout */ + data->watchdog_timeout = timeout; + + /* Check, if last reboot was caused by watchdog */ + data->watchdog_caused_reboot = + w83793_read_value(data->client, W83793_REG_WDT_STATUS) & 0x01; + + /* Disable Soft Watchdog during initialiation */ + watchdog_disable(data); + + /* We take the data_mutex lock early so that watchdog_open() cannot + run when misc_register() has completed, but we've not yet added + our data to the watchdog_data_list (and set the default timeout) */ + mutex_lock(&watchdog_data_mutex); + for (i = 0; i < ARRAY_SIZE(watchdog_minors); i++) { + /* Register our watchdog part */ + snprintf(data->watchdog_name, sizeof(data->watchdog_name), + "watchdog%c", (i == 0) ? '\0' : ('0' + i)); + data->watchdog_miscdev.name = data->watchdog_name; + data->watchdog_miscdev.fops = &watchdog_fops; + data->watchdog_miscdev.minor = watchdog_minors[i]; + + err = misc_register(&data->watchdog_miscdev); + if (err == -EBUSY) + continue; + if (err) { + data->watchdog_miscdev.minor = 0; + dev_err(&client->dev, + "Registering watchdog chardev: %d\n", err); + break; + } + + list_add(&data->list, &watchdog_data_list); + + dev_info(&client->dev, + "Registered watchdog chardev major 10, minor: %d\n", + watchdog_minors[i]); + break; + } + if (i == ARRAY_SIZE(watchdog_minors)) { + data->watchdog_miscdev.minor = 0; + dev_warn(&client->dev, "Couldn't register watchdog chardev " + "(due to no free minor)\n"); + } + + mutex_unlock(&watchdog_data_mutex); + return 0; + /* Unregister hwmon device */ + +exit_devunreg: + + hwmon_device_unregister(data->hwmon_dev); + /* Unregister sysfs hooks */ exit_remove: @@ -1628,7 +2104,7 @@ static void __exit sensors_w83793_exit(void) i2c_del_driver(&w83793_driver); } -MODULE_AUTHOR("Yuan Mu"); +MODULE_AUTHOR("Yuan Mu, Sven Anders"); MODULE_DESCRIPTION("w83793 driver"); MODULE_LICENSE("GPL"); |