/*
* 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", "triggered", 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
};
static const struct attribute_group ziirave_wdt_sysfs_files = {
.attrs = ziirave_wdt_attrs,
};
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;
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);
if (ret)
return ret;
ret = sysfs_create_group(&w_priv->wdd.dev->kobj,
&ziirave_wdt_sysfs_files);
if (ret) {
watchdog_unregister_device(&w_priv->wdd);
return ret;
}
return 0;
}
static int ziirave_wdt_remove(struct i2c_client *client)
{
struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
sysfs_remove_group(&client->dev.kobj, &ziirave_wdt_sysfs_files);
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");
