Re: [PATCH v3 2/3] watchdog: Add ChromeOS EC-based watchdog driver

Krzysztof Kozlowski
2024-01-22T10:31:55Z

On 19/01/2024 09:43, Lukasz Majczak wrote:
> Embedded Controller (EC) present on Chromebook devices
> can be used as a watchdog.
> Implement a driver to support it.
>

...

> +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(struct watchdog_device), GFP_KERNEL);

sizeof(*)

> + 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 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,
> + },
> +};
> +
> +module_platform_driver(cros_ec_wdt_driver);
> +
> +static const struct platform_device_id cros_ec_wdt_id[] = {
> + { DRV_NAME, 0 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(platform, cros_ec_wdt_id);

device_id is not placed here, please open existing drivers for
reference. Why this isn't referenced in driver structure?

> +MODULE_DESCRIPTION("Cros EC Watchdog Device Driver");
> +MODULE_LICENSE("GPL");

Best regards,
Krzysztof