kernel-ark/drivers/watchdog/menf21bmc_wdt.c
Pratyush Anand 6551881c86 Watchdog: Fix parent of watchdog_devices
/sys/class/watchdog/watchdogn/device/modalias can help to identify the
driver/module for a given watchdog node. However, many wdt devices do not
set their parent and so, we do not see an entry for device in sysfs for
such devices.

This patch fixes parent of watchdog_device so that
/sys/class/watchdog/watchdogn/device is populated.

Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not
have any parent. Not sure, how we can identify driver for these devices.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-09-09 21:39:22 +02:00

204 lines
5.4 KiB
C

/*
* MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
*
* Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#define DEVNAME "menf21bmc_wdt"
#define BMC_CMD_WD_ON 0x11
#define BMC_CMD_WD_OFF 0x12
#define BMC_CMD_WD_TRIG 0x13
#define BMC_CMD_WD_TIME 0x14
#define BMC_CMD_WD_STATE 0x17
#define BMC_WD_OFF_VAL 0x69
#define BMC_CMD_RST_RSN 0x92
#define BMC_WD_TIMEOUT_MIN 1 /* in sec */
#define BMC_WD_TIMEOUT_MAX 6553 /* in sec */
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) ")");
struct menf21bmc_wdt {
struct watchdog_device wdt;
struct i2c_client *i2c_client;
};
static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
{
int rst_rsn;
rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
if (rst_rsn < 0)
return rst_rsn;
if (rst_rsn == 0x02)
data->wdt.bootstatus |= WDIOF_CARDRESET;
else if (rst_rsn == 0x05)
data->wdt.bootstatus |= WDIOF_EXTERN1;
else if (rst_rsn == 0x06)
data->wdt.bootstatus |= WDIOF_EXTERN2;
else if (rst_rsn == 0x0A)
data->wdt.bootstatus |= WDIOF_POWERUNDER;
return 0;
}
static int menf21bmc_wdt_start(struct watchdog_device *wdt)
{
struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
}
static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
{
struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
return i2c_smbus_write_byte_data(drv_data->i2c_client,
BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
}
static int
menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
{
int ret;
struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
/*
* BMC Watchdog does have a resolution of 100ms.
* Watchdog API defines the timeout in seconds, so we have to
* multiply the value.
*/
ret = i2c_smbus_write_word_data(drv_data->i2c_client,
BMC_CMD_WD_TIME, timeout * 10);
if (ret < 0)
return ret;
wdt->timeout = timeout;
return 0;
}
static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
{
struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
}
static const struct watchdog_info menf21bmc_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = DEVNAME,
};
static const struct watchdog_ops menf21bmc_wdt_ops = {
.owner = THIS_MODULE,
.start = menf21bmc_wdt_start,
.stop = menf21bmc_wdt_stop,
.ping = menf21bmc_wdt_ping,
.set_timeout = menf21bmc_wdt_settimeout,
};
static int menf21bmc_wdt_probe(struct platform_device *pdev)
{
int ret, bmc_timeout;
struct menf21bmc_wdt *drv_data;
struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
drv_data = devm_kzalloc(&pdev->dev,
sizeof(struct menf21bmc_wdt), GFP_KERNEL);
if (!drv_data)
return -ENOMEM;
drv_data->wdt.ops = &menf21bmc_wdt_ops;
drv_data->wdt.info = &menf21bmc_wdt_info;
drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
drv_data->wdt.parent = &pdev->dev;
drv_data->i2c_client = i2c_client;
/*
* Get the current wdt timeout value from the BMC because
* the BMC will save the value set before if the system restarts.
*/
bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
BMC_CMD_WD_TIME);
if (bmc_timeout < 0) {
dev_err(&pdev->dev, "failed to get current WDT timeout\n");
return bmc_timeout;
}
watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
watchdog_set_nowayout(&drv_data->wdt, nowayout);
watchdog_set_drvdata(&drv_data->wdt, drv_data);
platform_set_drvdata(pdev, drv_data);
ret = menf21bmc_wdt_set_bootstatus(drv_data);
if (ret < 0) {
dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
return ret;
}
ret = watchdog_register_device(&drv_data->wdt);
if (ret) {
dev_err(&pdev->dev, "failed to register Watchdog device\n");
return ret;
}
dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
return 0;
}
static int menf21bmc_wdt_remove(struct platform_device *pdev)
{
struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
dev_warn(&pdev->dev,
"Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
watchdog_unregister_device(&drv_data->wdt);
return 0;
}
static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
{
struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
i2c_smbus_write_word_data(drv_data->i2c_client,
BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
}
static struct platform_driver menf21bmc_wdt = {
.driver = {
.name = DEVNAME,
},
.probe = menf21bmc_wdt_probe,
.remove = menf21bmc_wdt_remove,
.shutdown = menf21bmc_wdt_shutdown,
};
module_platform_driver(menf21bmc_wdt);
MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:menf21bmc_wdt");