linux/drivers/watchdog/ziirave_wdt.c
Martyn Welch 0ce72f3544 watchdog: ziirave_wdt: Rename "trigger" reset reason "hw watchdog"
The Zodiac watchdog is implemented on a microcontoller. The reset reason
currently labelled "trigger" is not to detect when the watchdog has
triggered (as had been initially understood and suggested by the naming),
but to inform the reader that the watchdog, which in fact has it's own
hardware watchdog, has been reset because the hardware watchdog has
triggered. Renaming to "hw watchdog".

Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-01 15:30:16 +01:00

368 lines
9.3 KiB
C

/*
* Copyright (C) 2015 Zodiac Inflight Innovations
*
* Author: Martyn Welch <martyn.welch@collabora.co.uk>
*
* Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
*
* Copyright (C) Nokia Corporation
*
* 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
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/version.h>
#include <linux/watchdog.h>
#define ZIIRAVE_TIMEOUT_MIN 3
#define ZIIRAVE_TIMEOUT_MAX 255
#define ZIIRAVE_PING_VALUE 0x0
#define ZIIRAVE_STATE_INITIAL 0x0
#define ZIIRAVE_STATE_OFF 0x1
#define ZIIRAVE_STATE_ON 0x2
static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
"host request", NULL, "illegal configuration",
"illegal instruction", "illegal trap",
"unknown"};
#define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1
#define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3
#define ZIIRAVE_WDT_RESET_REASON 0x5
#define ZIIRAVE_WDT_STATE 0x6
#define ZIIRAVE_WDT_TIMEOUT 0x7
#define ZIIRAVE_WDT_TIME_LEFT 0x8
#define ZIIRAVE_WDT_PING 0x9
#define ZIIRAVE_WDT_RESET_DURATION 0xa
struct ziirave_wdt_rev {
unsigned char major;
unsigned char minor;
};
struct ziirave_wdt_data {
struct watchdog_device wdd;
struct ziirave_wdt_rev bootloader_rev;
struct ziirave_wdt_rev firmware_rev;
int reset_reason;
};
static int wdt_timeout;
module_param(wdt_timeout, int, 0);
MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");
static int reset_duration;
module_param(reset_duration, int, 0);
MODULE_PARM_DESC(reset_duration,
"Watchdog reset pulse duration in milliseconds");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int ziirave_wdt_revision(struct i2c_client *client,
struct ziirave_wdt_rev *rev, u8 command)
{
int ret;
ret = i2c_smbus_read_byte_data(client, command);
if (ret < 0)
return ret;
rev->major = ret;
ret = i2c_smbus_read_byte_data(client, command + 1);
if (ret < 0)
return ret;
rev->minor = ret;
return 0;
}
static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
}
static int ziirave_wdt_start(struct watchdog_device *wdd)
{
return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
}
static int ziirave_wdt_stop(struct watchdog_device *wdd)
{
return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
}
static int ziirave_wdt_ping(struct watchdog_device *wdd)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
ZIIRAVE_PING_VALUE);
}
static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
int ret;
ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
if (!ret)
wdd->timeout = timeout;
return ret;
}
static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
int ret;
ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
if (ret < 0)
ret = 0;
return ret;
}
static const struct watchdog_info ziirave_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "Zodiac RAVE Watchdog",
};
static const struct watchdog_ops ziirave_wdt_ops = {
.owner = THIS_MODULE,
.start = ziirave_wdt_start,
.stop = ziirave_wdt_stop,
.ping = ziirave_wdt_ping,
.set_timeout = ziirave_wdt_set_timeout,
.get_timeleft = ziirave_wdt_get_timeleft,
};
static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
w_priv->firmware_rev.minor);
}
static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
NULL);
static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
w_priv->bootloader_rev.minor);
}
static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
NULL);
static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev->parent);
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
}
static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
NULL);
static struct attribute *ziirave_wdt_attrs[] = {
&dev_attr_firmware_version.attr,
&dev_attr_bootloader_version.attr,
&dev_attr_reset_reason.attr,
NULL
};
ATTRIBUTE_GROUPS(ziirave_wdt);
static int ziirave_wdt_init_duration(struct i2c_client *client)
{
int ret;
if (!reset_duration) {
/* See if the reset pulse duration is provided in an of_node */
if (!client->dev.of_node)
ret = -ENODEV;
else
ret = of_property_read_u32(client->dev.of_node,
"reset-duration-ms",
&reset_duration);
if (ret) {
dev_info(&client->dev,
"Unable to set reset pulse duration, using default\n");
return 0;
}
}
if (reset_duration < 1 || reset_duration > 255)
return -EINVAL;
dev_info(&client->dev, "Setting reset duration to %dms",
reset_duration);
return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
reset_duration);
}
static int ziirave_wdt_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct ziirave_wdt_data *w_priv;
int val;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -ENODEV;
w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
if (!w_priv)
return -ENOMEM;
w_priv->wdd.info = &ziirave_wdt_info;
w_priv->wdd.ops = &ziirave_wdt_ops;
w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
w_priv->wdd.parent = &client->dev;
w_priv->wdd.groups = ziirave_wdt_groups;
ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
if (ret) {
dev_info(&client->dev,
"Unable to select timeout value, using default\n");
}
/*
* The default value set in the watchdog should be perfectly valid, so
* pass that in if we haven't provided one via the module parameter or
* of property.
*/
if (w_priv->wdd.timeout == 0) {
val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
if (val < 0)
return val;
if (val < ZIIRAVE_TIMEOUT_MIN)
return -ENODEV;
w_priv->wdd.timeout = val;
} else {
ret = ziirave_wdt_set_timeout(&w_priv->wdd,
w_priv->wdd.timeout);
if (ret)
return ret;
dev_info(&client->dev, "Timeout set to %ds.",
w_priv->wdd.timeout);
}
watchdog_set_nowayout(&w_priv->wdd, nowayout);
i2c_set_clientdata(client, w_priv);
/* If in unconfigured state, set to stopped */
val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
if (val < 0)
return val;
if (val == ZIIRAVE_STATE_INITIAL)
ziirave_wdt_stop(&w_priv->wdd);
ret = ziirave_wdt_init_duration(client);
if (ret)
return ret;
ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
ZIIRAVE_WDT_FIRM_VER_MAJOR);
if (ret)
return ret;
ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
ZIIRAVE_WDT_BOOT_VER_MAJOR);
if (ret)
return ret;
w_priv->reset_reason = i2c_smbus_read_byte_data(client,
ZIIRAVE_WDT_RESET_REASON);
if (w_priv->reset_reason < 0)
return w_priv->reset_reason;
if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
!ziirave_reasons[w_priv->reset_reason])
return -ENODEV;
ret = watchdog_register_device(&w_priv->wdd);
return ret;
}
static int ziirave_wdt_remove(struct i2c_client *client)
{
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
watchdog_unregister_device(&w_priv->wdd);
return 0;
}
static struct i2c_device_id ziirave_wdt_id[] = {
{ "ziirave-wdt", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);
static const struct of_device_id zrv_wdt_of_match[] = {
{ .compatible = "zii,rave-wdt", },
{ },
};
MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);
static struct i2c_driver ziirave_wdt_driver = {
.driver = {
.name = "ziirave_wdt",
.of_match_table = zrv_wdt_of_match,
},
.probe = ziirave_wdt_probe,
.remove = ziirave_wdt_remove,
.id_table = ziirave_wdt_id,
};
module_i2c_driver(ziirave_wdt_driver);
MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk");
MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
MODULE_LICENSE("GPL");