--- /dev/null
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2012, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/watchdog.h>
+
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+#include "hbm.h"
+#include "client.h"
+
+static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
+static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
+
+/*
+ * AMT Watchdog Device
+ */
+#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
+
+/* UUIDs for AMT F/W clients */
+const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
+ 0x9D, 0xA9, 0x15, 0x14, 0xCB,
+ 0x32, 0xAB);
+
+static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
+{
+ dev_dbg(dev->dev, "wd: set timeout=%d.\n", timeout);
+ memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE);
+ memcpy(dev->wd_data + MEI_WD_HDR_SIZE, &timeout, sizeof(u16));
+}
+
+/**
+ * mei_wd_host_init - connect to the watchdog client
+ *
+ * @dev: the device structure
+ *
+ * Return: -ENOTTY if wd client cannot be found
+ * -EIO if write has failed
+ * 0 on success
+ */
+int mei_wd_host_init(struct mei_device *dev)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ struct mei_me_client *me_cl;
+ int ret;
+
+ mei_cl_init(cl, dev);
+
+ dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
+ dev->wd_state = MEI_WD_IDLE;
+
+
+ /* check for valid client id */
+ me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid);
+ if (!me_cl) {
+ dev_info(dev->dev, "wd: failed to find the client\n");
+ return -ENOTTY;
+ }
+
+ cl->me_client_id = me_cl->client_id;
+ cl->cl_uuid = me_cl->props.protocol_name;
+ mei_me_cl_put(me_cl);
+
+ ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
+
+ if (ret < 0) {
+ dev_info(dev->dev, "wd: failed link client\n");
+ return ret;
+ }
+
+ ret = mei_cl_connect(cl, NULL);
+
+ if (ret) {
+ dev_err(dev->dev, "wd: failed to connect = %d\n", ret);
+ mei_cl_unlink(cl);
+ return ret;
+ }
+
+ ret = mei_watchdog_register(dev);
+ if (ret) {
+ mei_cl_disconnect(cl);
+ mei_cl_unlink(cl);
+ }
+ return ret;
+}
+
+/**
+ * mei_wd_send - sends watch dog message to fw.
+ *
+ * @dev: the device structure
+ *
+ * Return: 0 if success,
+ * -EIO when message send fails
+ * -EINVAL when invalid message is to be sent
+ * -ENODEV on flow control failure
+ */
+int mei_wd_send(struct mei_device *dev)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ struct mei_msg_hdr hdr;
+ int ret;
+
+ hdr.host_addr = cl->host_client_id;
+ hdr.me_addr = cl->me_client_id;
+ hdr.msg_complete = 1;
+ hdr.reserved = 0;
+ hdr.internal = 0;
+
+ if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_HDR_SIZE))
+ hdr.length = MEI_WD_START_MSG_SIZE;
+ else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_HDR_SIZE))
+ hdr.length = MEI_WD_STOP_MSG_SIZE;
+ else {
+ dev_err(dev->dev, "wd: invalid message is to be sent, aborting\n");
+ return -EINVAL;
+ }
+
+ ret = mei_write_message(dev, &hdr, dev->wd_data);
+ if (ret) {
+ dev_err(dev->dev, "wd: write message failed\n");
+ return ret;
+ }
+
+ ret = mei_cl_flow_ctrl_reduce(cl);
+ if (ret) {
+ dev_err(dev->dev, "wd: flow_ctrl_reduce failed.\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * mei_wd_stop - sends watchdog stop message to fw.
+ *
+ * @dev: the device structure
+ *
+ * Return: 0 if success
+ * on error:
+ * -EIO when message send fails
+ * -EINVAL when invalid message is to be sent
+ * -ETIME on message timeout
+ */
+int mei_wd_stop(struct mei_device *dev)
+{
+ struct mei_cl *cl = &dev->wd_cl;
+ int ret;
+
+ if (!mei_cl_is_connected(cl) ||
+ dev->wd_state != MEI_WD_RUNNING)
+ return 0;
+
+ memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
+
+ dev->wd_state = MEI_WD_STOPPING;
+
+ ret = mei_cl_flow_ctrl_creds(cl);
+ if (ret < 0)
+ goto err;
+
+ if (ret && mei_hbuf_acquire(dev)) {
+ ret = mei_wd_send(dev);
+ if (ret)
+ goto err;
+ dev->wd_pending = false;
+ } else {
+ dev->wd_pending = true;
+ }
+
+ mutex_unlock(&dev->device_lock);
+
+ ret = wait_event_timeout(dev->wait_stop_wd,
+ dev->wd_state == MEI_WD_IDLE,
+ msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
+ mutex_lock(&dev->device_lock);
+ if (dev->wd_state != MEI_WD_IDLE) {
+ /* timeout */
+ ret = -ETIME;
+ dev_warn(dev->dev, "wd: stop failed to complete ret=%d\n", ret);
+ goto err;
+ }
+ dev_dbg(dev->dev, "wd: stop completed after %u msec\n",
+ MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
+ return 0;
+err:
+ return ret;
+}
+
+/**
+ * mei_wd_ops_start - wd start command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_start(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl;
+ int err = -ENODEV;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ cl = &dev->wd_cl;
+
+ mutex_lock(&dev->device_lock);
+
+ if (dev->dev_state != MEI_DEV_ENABLED) {
+ dev_dbg(dev->dev, "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
+ mei_dev_state_str(dev->dev_state));
+ goto end_unlock;
+ }
+
+ if (!mei_cl_is_connected(cl)) {
+ cl_dbg(dev, cl, "MEI Driver is not connected to Watchdog Client\n");
+ goto end_unlock;
+ }
+
+ mei_wd_set_start_timeout(dev, dev->wd_timeout);
+
+ err = 0;
+end_unlock:
+ mutex_unlock(&dev->device_lock);
+ return err;
+}
+
+/**
+ * mei_wd_ops_stop - wd stop command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ mutex_lock(&dev->device_lock);
+ mei_wd_stop(dev);
+ mutex_unlock(&dev->device_lock);
+
+ return 0;
+}
+
+/**
+ * mei_wd_ops_ping - wd ping command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
+{
+ struct mei_device *dev;
+ struct mei_cl *cl;
+ int ret;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ cl = &dev->wd_cl;
+
+ mutex_lock(&dev->device_lock);
+
+ if (!mei_cl_is_connected(cl)) {
+ cl_err(dev, cl, "wd: not connected.\n");
+ ret = -ENODEV;
+ goto end;
+ }
+
+ dev->wd_state = MEI_WD_RUNNING;
+
+ ret = mei_cl_flow_ctrl_creds(cl);
+ if (ret < 0)
+ goto end;
+
+ /* Check if we can send the ping to HW*/
+ if (ret && mei_hbuf_acquire(dev)) {
+ dev_dbg(dev->dev, "wd: sending ping\n");
+
+ ret = mei_wd_send(dev);
+ if (ret)
+ goto end;
+ dev->wd_pending = false;
+ } else {
+ dev->wd_pending = true;
+ }
+
+end:
+ mutex_unlock(&dev->device_lock);
+ return ret;
+}
+
+/**
+ * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
+ *
+ * @wd_dev: watchdog device struct
+ * @timeout: timeout value to set
+ *
+ * Return: 0 if success, negative errno code for failure
+ */
+static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev,
+ unsigned int timeout)
+{
+ struct mei_device *dev;
+
+ dev = watchdog_get_drvdata(wd_dev);
+ if (!dev)
+ return -ENODEV;
+
+ /* Check Timeout value */
+ if (timeout < MEI_WD_MIN_TIMEOUT || timeout > MEI_WD_MAX_TIMEOUT)
+ return -EINVAL;
+
+ mutex_lock(&dev->device_lock);
+
+ dev->wd_timeout = timeout;
+ wd_dev->timeout = timeout;
+ mei_wd_set_start_timeout(dev, dev->wd_timeout);
+
+ mutex_unlock(&dev->device_lock);
+
+ return 0;
+}
+
+/*
+ * Watchdog Device structs
+ */
+static const struct watchdog_ops wd_ops = {
+ .owner = THIS_MODULE,
+ .start = mei_wd_ops_start,
+ .stop = mei_wd_ops_stop,
+ .ping = mei_wd_ops_ping,
+ .set_timeout = mei_wd_ops_set_timeout,
+};
+static const struct watchdog_info wd_info = {
+ .identity = INTEL_AMT_WATCHDOG_ID,
+ .options = WDIOF_KEEPALIVEPING |
+ WDIOF_SETTIMEOUT |
+ WDIOF_ALARMONLY,
+};
+
+static struct watchdog_device amt_wd_dev = {
+ .info = &wd_info,
+ .ops = &wd_ops,
+ .timeout = MEI_WD_DEFAULT_TIMEOUT,
+ .min_timeout = MEI_WD_MIN_TIMEOUT,
+ .max_timeout = MEI_WD_MAX_TIMEOUT,
+};
+
+
+int mei_watchdog_register(struct mei_device *dev)
+{
+
+ int ret;
+
+ /* unlock to perserve correct locking order */
+ mutex_unlock(&dev->device_lock);
+ ret = watchdog_register_device(&amt_wd_dev);
+ mutex_lock(&dev->device_lock);
+ if (ret) {
+ dev_err(dev->dev, "wd: unable to register watchdog device = %d.\n",
+ ret);
+ return ret;
+ }
+
+ dev_dbg(dev->dev, "wd: successfully register watchdog interface.\n");
+ watchdog_set_drvdata(&amt_wd_dev, dev);
+ return 0;
+}
+
+void mei_watchdog_unregister(struct mei_device *dev)
+{
+ if (watchdog_get_drvdata(&amt_wd_dev) == NULL)
+ return;
+
+ watchdog_set_drvdata(&amt_wd_dev, NULL);
+ watchdog_unregister_device(&amt_wd_dev);
+}
+
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