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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2024 Google LLC.
* Author: Lukasz Majczak <lma@chromium.com>
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#define CROS_EC_WATCHDOG_DEFAULT_TIME 30 /* seconds */
#define DRV_NAME "cros-ec-wdt"
union cros_ec_wdt_data {
struct ec_params_hang_detect req;
struct ec_response_hang_detect resp;
} __packed;
static int cros_ec_wdt_send_cmd(struct cros_ec_device *cros_ec,
union cros_ec_wdt_data *arg)
{
int ret;
struct {
struct cros_ec_command msg;
union cros_ec_wdt_data data;
} __packed buf = {
.msg = {
.version = 0,
.command = EC_CMD_HANG_DETECT,
.insize = (arg->req.command == EC_HANG_DETECT_CMD_GET_STATUS) ?
sizeof(struct ec_response_hang_detect) :
0,
.outsize = sizeof(struct ec_params_hang_detect),
},
.data.req = arg->req
};
ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
if (ret < 0)
return ret;
arg->resp = buf.data.resp;
return 0;
}
static int cros_ec_wdt_ping(struct watchdog_device *wdd)
{
struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd);
union cros_ec_wdt_data arg;
int ret;
arg.req.command = EC_HANG_DETECT_CMD_RELOAD;
ret = cros_ec_wdt_send_cmd(cros_ec, &arg);
if (ret < 0)
dev_dbg(wdd->parent, "Failed to ping watchdog (%d)", ret);
return ret;
}
static int cros_ec_wdt_start(struct watchdog_device *wdd)
{
struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd);
union cros_ec_wdt_data arg;
int ret;
/* Prepare watchdog on EC side */
arg.req.command = EC_HANG_DETECT_CMD_SET_TIMEOUT;
arg.req.reboot_timeout_sec = wdd->timeout;
ret = cros_ec_wdt_send_cmd(cros_ec, &arg);
if (ret < 0)
dev_dbg(wdd->parent, "Failed to start watchdog (%d)", ret);
return ret;
}
static int cros_ec_wdt_stop(struct watchdog_device *wdd)
{
struct cros_ec_device *cros_ec = watchdog_get_drvdata(wdd);
union cros_ec_wdt_data arg;
int ret;
arg.req.command = EC_HANG_DETECT_CMD_CANCEL;
ret = cros_ec_wdt_send_cmd(cros_ec, &arg);
if (ret < 0)
dev_dbg(wdd->parent, "Failed to stop watchdog (%d)", ret);
return ret;
}
static int cros_ec_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
unsigned int old_timeout = wdd->timeout;
int ret;
wdd->timeout = t;
ret = cros_ec_wdt_start(wdd);
if (ret < 0)
wdd->timeout = old_timeout;
return ret;
}
static const struct watchdog_info cros_ec_wdt_ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = DRV_NAME,
};
static const struct watchdog_ops cros_ec_wdt_ops = {
.owner = THIS_MODULE,
.ping = cros_ec_wdt_ping,
.start = cros_ec_wdt_start,
.stop = cros_ec_wdt_stop,
.set_timeout = cros_ec_wdt_set_timeout,
};
static int cros_ec_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
struct cros_ec_device *cros_ec = ec_dev->ec_dev;
struct watchdog_device *wdd;
union cros_ec_wdt_data arg;
int ret = 0;
wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
if (!wdd)
return -ENOMEM;
arg.req.command = EC_HANG_DETECT_CMD_GET_STATUS;
ret = cros_ec_wdt_send_cmd(cros_ec, &arg);
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to get watchdog bootstatus");
wdd->parent = &pdev->dev;
wdd->info = &cros_ec_wdt_ident;
wdd->ops = &cros_ec_wdt_ops;
wdd->timeout = CROS_EC_WATCHDOG_DEFAULT_TIME;
wdd->min_timeout = EC_HANG_DETECT_MIN_TIMEOUT;
wdd->max_timeout = EC_HANG_DETECT_MAX_TIMEOUT;
if (arg.resp.status == EC_HANG_DETECT_AP_BOOT_EC_WDT)
wdd->bootstatus = WDIOF_CARDRESET;
arg.req.command = EC_HANG_DETECT_CMD_CLEAR_STATUS;
ret = cros_ec_wdt_send_cmd(cros_ec, &arg);
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to clear watchdog bootstatus");
watchdog_stop_on_reboot(wdd);
watchdog_stop_on_unregister(wdd);
watchdog_set_drvdata(wdd, cros_ec);
platform_set_drvdata(pdev, wdd);
return devm_watchdog_register_device(dev, wdd);
}
static int __maybe_unused cros_ec_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
struct watchdog_device *wdd = platform_get_drvdata(pdev);
int ret = 0;
if (watchdog_active(wdd))
ret = cros_ec_wdt_stop(wdd);
return ret;
}
static int __maybe_unused cros_ec_wdt_resume(struct platform_device *pdev)
{
struct watchdog_device *wdd = platform_get_drvdata(pdev);
int ret = 0;
if (watchdog_active(wdd))
ret = cros_ec_wdt_start(wdd);
return ret;
}
static const struct platform_device_id cros_ec_wdt_id[] = {
{ DRV_NAME, 0 },
{}
};
static struct platform_driver cros_ec_wdt_driver = {
.probe = cros_ec_wdt_probe,
.suspend = pm_ptr(cros_ec_wdt_suspend),
.resume = pm_ptr(cros_ec_wdt_resume),
.driver = {
.name = DRV_NAME,
},
.id_table = cros_ec_wdt_id,
};
module_platform_driver(cros_ec_wdt_driver);
MODULE_DEVICE_TABLE(platform, cros_ec_wdt_id);
MODULE_DESCRIPTION("Cros EC Watchdog Device Driver");
MODULE_LICENSE("GPL");
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