diff options
Diffstat (limited to 'drivers/watchdog/cros_ec_wdt.c')
| -rw-r--r-- | drivers/watchdog/cros_ec_wdt.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/watchdog/cros_ec_wdt.c b/drivers/watchdog/cros_ec_wdt.c new file mode 100644 index 0000000000..ba045e29f9 --- /dev/null +++ b/drivers/watchdog/cros_ec_wdt.c @@ -0,0 +1,204 @@ +// 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"); |