// SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (C) 2018-2019, Intel Corporation
   */
  
  #include <linux/arm-smccc.h>
  #include <linux/bitfield.h>
  #include <linux/completion.h>
  #include <linux/kobject.h>
  #include <linux/module.h>
  #include <linux/mutex.h>
  #include <linux/of.h>
  #include <linux/of_platform.h>
  #include <linux/platform_device.h>
  #include <linux/firmware/intel/stratix10-svc-client.h>
  #include <linux/string.h>
  #include <linux/sysfs.h>
  
  #define RSU_STATE_MASK			GENMASK_ULL(31, 0)
  #define RSU_VERSION_MASK		GENMASK_ULL(63, 32)
  #define RSU_ERROR_LOCATION_MASK		GENMASK_ULL(31, 0)
  #define RSU_ERROR_DETAIL_MASK		GENMASK_ULL(63, 32)

  #define RSU_DCMF0_MASK			GENMASK_ULL(31, 0)
  #define RSU_DCMF1_MASK			GENMASK_ULL(63, 32)
  #define RSU_DCMF2_MASK			GENMASK_ULL(31, 0)
  #define RSU_DCMF3_MASK			GENMASK_ULL(63, 32)

  
  #define RSU_TIMEOUT	(msecs_to_jiffies(SVC_RSU_REQUEST_TIMEOUT_MS))

  #define INVALID_RETRY_COUNTER		0xFF
  #define INVALID_DCMF_VERSION		0xFF

  
  typedef void (*rsu_callback)(struct stratix10_svc_client *client,
  			     struct stratix10_svc_cb_data *data);
  /**
   * struct stratix10_rsu_priv - rsu data structure
   * @chan: pointer to the allocated service channel
   * @client: active service client
   * @completion: state for callback completion
   * @lock: a mutex to protect callback completion state
   * @status.current_image: address of image currently running in flash
   * @status.fail_image: address of failed image in flash

   * @status.version: the interface version number of RSU firmware

   * @status.state: the state of RSU system
   * @status.error_details: error code
   * @status.error_location: the error offset inside the image that failed

   * @dcmf_version.dcmf0: Quartus dcmf0 version
   * @dcmf_version.dcmf1: Quartus dcmf1 version
   * @dcmf_version.dcmf2: Quartus dcmf2 version
   * @dcmf_version.dcmf3: Quartus dcmf3 version

   * @retry_counter: the current image's retry counter

   * @max_retry: the preset max retry value

   */
  struct stratix10_rsu_priv {
  	struct stratix10_svc_chan *chan;
  	struct stratix10_svc_client client;
  	struct completion completion;
  	struct mutex lock;
  	struct {
  		unsigned long current_image;
  		unsigned long fail_image;
  		unsigned int version;
  		unsigned int state;
  		unsigned int error_details;
  		unsigned int error_location;
  	} status;

  
  	struct {
  		unsigned int dcmf0;
  		unsigned int dcmf1;
  		unsigned int dcmf2;
  		unsigned int dcmf3;
  	} dcmf_version;

  	unsigned int retry_counter;

  	unsigned int max_retry;

  };
  
  /**
   * rsu_status_callback() - Status callback from Intel Service Layer
   * @client: pointer to service client
   * @data: pointer to callback data structure
   *
   * Callback from Intel service layer for RSU status request. Status is
   * only updated after a system reboot, so a get updated status call is
   * made during driver probe.
   */
  static void rsu_status_callback(struct stratix10_svc_client *client,
  				struct stratix10_svc_cb_data *data)
  {
  	struct stratix10_rsu_priv *priv = client->priv;
  	struct arm_smccc_res *res = (struct arm_smccc_res *)data->kaddr1;

  	if (data->status == BIT(SVC_STATUS_OK)) {

  		priv->status.version = FIELD_GET(RSU_VERSION_MASK,
  						 res->a2);
  		priv->status.state = FIELD_GET(RSU_STATE_MASK, res->a2);
  		priv->status.fail_image = res->a1;
  		priv->status.current_image = res->a0;
  		priv->status.error_location =
  			FIELD_GET(RSU_ERROR_LOCATION_MASK, res->a3);
  		priv->status.error_details =
  			FIELD_GET(RSU_ERROR_DETAIL_MASK, res->a3);
  	} else {
  		dev_err(client->dev, "COMMAND_RSU_STATUS returned 0x%lX
  ",
  			res->a0);
  		priv->status.version = 0;
  		priv->status.state = 0;
  		priv->status.fail_image = 0;
  		priv->status.current_image = 0;
  		priv->status.error_location = 0;
  		priv->status.error_details = 0;
  	}
  
  	complete(&priv->completion);
  }
  
  /**
   * rsu_command_callback() - Update callback from Intel Service Layer
   * @client: pointer to client
   * @data: pointer to callback data structure
   *
   * Callback from Intel service layer for RSU commands.
   */
  static void rsu_command_callback(struct stratix10_svc_client *client,
  				 struct stratix10_svc_cb_data *data)
  {
  	struct stratix10_rsu_priv *priv = client->priv;

  	if (data->status == BIT(SVC_STATUS_NO_SUPPORT))

  		dev_warn(client->dev, "FW doesn't support notify
  ");

  	else if (data->status == BIT(SVC_STATUS_ERROR))

  		dev_err(client->dev, "Failure, returned status is %lu
  ",
  			BIT(data->status));

  	complete(&priv->completion);
  }
  
  /**
   * rsu_retry_callback() - Callback from Intel service layer for getting

   * the current image's retry counter from the firmware

   * @client: pointer to client
   * @data: pointer to callback data structure
   *
   * Callback from Intel service layer for retry counter, which is used by
   * user to know how many times the images is still allowed to reload
   * itself before giving up and starting RSU fail-over flow.
   */
  static void rsu_retry_callback(struct stratix10_svc_client *client,
  			       struct stratix10_svc_cb_data *data)
  {
  	struct stratix10_rsu_priv *priv = client->priv;
  	unsigned int *counter = (unsigned int *)data->kaddr1;

  	if (data->status == BIT(SVC_STATUS_OK))

  		priv->retry_counter = *counter;

  	else if (data->status == BIT(SVC_STATUS_NO_SUPPORT))

  		dev_warn(client->dev, "FW doesn't support retry
  ");

  	else

  		dev_err(client->dev, "Failed to get retry counter %lu
  ",
  			BIT(data->status));

  
  	complete(&priv->completion);
  }
  
  /**

   * rsu_max_retry_callback() - Callback from Intel service layer for getting
   * the max retry value from the firmware
   * @client: pointer to client
   * @data: pointer to callback data structure
   *
   * Callback from Intel service layer for max retry.
   */
  static void rsu_max_retry_callback(struct stratix10_svc_client *client,
  				   struct stratix10_svc_cb_data *data)
  {
  	struct stratix10_rsu_priv *priv = client->priv;
  	unsigned int *max_retry = (unsigned int *)data->kaddr1;
  
  	if (data->status == BIT(SVC_STATUS_OK))
  		priv->max_retry = *max_retry;
  	else if (data->status == BIT(SVC_STATUS_NO_SUPPORT))
  		dev_warn(client->dev, "FW doesn't support max retry
  ");
  	else
  		dev_err(client->dev, "Failed to get max retry %lu
  ",
  			BIT(data->status));
  
  	complete(&priv->completion);
  }
  
  /**
   * rsu_dcmf_version_callback() - Callback from Intel service layer for getting
   * the DCMF version
   * @client: pointer to client
   * @data: pointer to callback data structure
   *
   * Callback from Intel service layer for DCMF version number
   */
  static void rsu_dcmf_version_callback(struct stratix10_svc_client *client,
  				      struct stratix10_svc_cb_data *data)
  {
  	struct stratix10_rsu_priv *priv = client->priv;
  	unsigned long long *value1 = (unsigned long long *)data->kaddr1;
  	unsigned long long *value2 = (unsigned long long *)data->kaddr2;
  
  	if (data->status == BIT(SVC_STATUS_OK)) {
  		priv->dcmf_version.dcmf0 = FIELD_GET(RSU_DCMF0_MASK, *value1);
  		priv->dcmf_version.dcmf1 = FIELD_GET(RSU_DCMF1_MASK, *value1);
  		priv->dcmf_version.dcmf2 = FIELD_GET(RSU_DCMF2_MASK, *value2);
  		priv->dcmf_version.dcmf3 = FIELD_GET(RSU_DCMF3_MASK, *value2);
  	} else
  		dev_err(client->dev, "failed to get DCMF version
  ");
  
  	complete(&priv->completion);
  }
  
  /**

   * rsu_send_msg() - send a message to Intel service layer
   * @priv: pointer to rsu private data
   * @command: RSU status or update command
   * @arg: the request argument, the bitstream address or notify status
   * @callback: function pointer for the callback (status or update)
   *
   * Start an Intel service layer transaction to perform the SMC call that
   * is necessary to get RSU boot log or set the address of bitstream to
   * boot after reboot.
   *
   * Returns 0 on success or -ETIMEDOUT on error.
   */
  static int rsu_send_msg(struct stratix10_rsu_priv *priv,
  			enum stratix10_svc_command_code command,
  			unsigned long arg,
  			rsu_callback callback)
  {
  	struct stratix10_svc_client_msg msg;
  	int ret;
  
  	mutex_lock(&priv->lock);
  	reinit_completion(&priv->completion);
  	priv->client.receive_cb = callback;
  
  	msg.command = command;
  	if (arg)
  		msg.arg[0] = arg;
  
  	ret = stratix10_svc_send(priv->chan, &msg);
  	if (ret < 0)
  		goto status_done;
  
  	ret = wait_for_completion_interruptible_timeout(&priv->completion,
  							RSU_TIMEOUT);
  	if (!ret) {
  		dev_err(priv->client.dev,
  			"timeout waiting for SMC call
  ");
  		ret = -ETIMEDOUT;
  		goto status_done;
  	} else if (ret < 0) {
  		dev_err(priv->client.dev,
  			"error %d waiting for SMC call
  ", ret);
  		goto status_done;
  	} else {
  		ret = 0;
  	}
  
  status_done:
  	stratix10_svc_done(priv->chan);
  	mutex_unlock(&priv->lock);
  	return ret;
  }
  
  /*
   * This driver exposes some optional features of the Intel Stratix 10 SoC FPGA.
   * The sysfs interfaces exposed here are FPGA Remote System Update (RSU)
   * related. They allow user space software to query the configuration system
   * status and to request optional reboot behavior specific to Intel FPGAs.
   */
  
  static ssize_t current_image_show(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08lx
  ", priv->status.current_image);
  }
  
  static ssize_t fail_image_show(struct device *dev,
  			       struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08lx
  ", priv->status.fail_image);
  }
  
  static ssize_t version_show(struct device *dev, struct device_attribute *attr,
  			    char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->status.version);
  }
  
  static ssize_t state_show(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->status.state);
  }
  
  static ssize_t error_location_show(struct device *dev,
  				   struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->status.error_location);
  }
  
  static ssize_t error_details_show(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->status.error_details);
  }
  
  static ssize_t retry_counter_show(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->retry_counter);
  }

  static ssize_t max_retry_show(struct device *dev,
  			      struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->max_retry);
  }
  
  static ssize_t dcmf0_show(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->dcmf_version.dcmf0);
  }
  
  static ssize_t dcmf1_show(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->dcmf_version.dcmf1);
  }
  
  static ssize_t dcmf2_show(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->dcmf_version.dcmf2);
  }
  
  static ssize_t dcmf3_show(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  
  	if (!priv)
  		return -ENODEV;
  
  	return sprintf(buf, "0x%08x
  ", priv->dcmf_version.dcmf3);
  }

  static ssize_t reboot_image_store(struct device *dev,
  				  struct device_attribute *attr,
  				  const char *buf, size_t count)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  	unsigned long address;
  	int ret;

  	if (!priv)

  		return -ENODEV;
  
  	ret = kstrtoul(buf, 0, &address);
  	if (ret)
  		return ret;
  
  	ret = rsu_send_msg(priv, COMMAND_RSU_UPDATE,
  			   address, rsu_command_callback);
  	if (ret) {
  		dev_err(dev, "Error, RSU update returned %i
  ", ret);
  		return ret;
  	}
  
  	return count;
  }
  
  static ssize_t notify_store(struct device *dev,
  			    struct device_attribute *attr,
  			    const char *buf, size_t count)
  {
  	struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
  	unsigned long status;
  	int ret;

  	if (!priv)

  		return -ENODEV;
  
  	ret = kstrtoul(buf, 0, &status);
  	if (ret)
  		return ret;
  
  	ret = rsu_send_msg(priv, COMMAND_RSU_NOTIFY,
  			   status, rsu_command_callback);
  	if (ret) {
  		dev_err(dev, "Error, RSU notify returned %i
  ", ret);
  		return ret;
  	}
  
  	/* to get the updated state */
  	ret = rsu_send_msg(priv, COMMAND_RSU_STATUS,
  			   0, rsu_status_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting RSU status %i
  ", ret);
  		return ret;
  	}

  	ret = rsu_send_msg(priv, COMMAND_RSU_RETRY, 0, rsu_retry_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting RSU retry %i
  ", ret);
  		return ret;

  	}
  
  	return count;
  }
  
  static DEVICE_ATTR_RO(current_image);
  static DEVICE_ATTR_RO(fail_image);
  static DEVICE_ATTR_RO(state);
  static DEVICE_ATTR_RO(version);
  static DEVICE_ATTR_RO(error_location);
  static DEVICE_ATTR_RO(error_details);
  static DEVICE_ATTR_RO(retry_counter);

  static DEVICE_ATTR_RO(max_retry);
  static DEVICE_ATTR_RO(dcmf0);
  static DEVICE_ATTR_RO(dcmf1);
  static DEVICE_ATTR_RO(dcmf2);
  static DEVICE_ATTR_RO(dcmf3);

  static DEVICE_ATTR_WO(reboot_image);
  static DEVICE_ATTR_WO(notify);
  
  static struct attribute *rsu_attrs[] = {
  	&dev_attr_current_image.attr,
  	&dev_attr_fail_image.attr,
  	&dev_attr_state.attr,
  	&dev_attr_version.attr,
  	&dev_attr_error_location.attr,
  	&dev_attr_error_details.attr,
  	&dev_attr_retry_counter.attr,

  	&dev_attr_max_retry.attr,
  	&dev_attr_dcmf0.attr,
  	&dev_attr_dcmf1.attr,
  	&dev_attr_dcmf2.attr,
  	&dev_attr_dcmf3.attr,

  	&dev_attr_reboot_image.attr,
  	&dev_attr_notify.attr,
  	NULL
  };
  
  ATTRIBUTE_GROUPS(rsu);
  
  static int stratix10_rsu_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct stratix10_rsu_priv *priv;
  	int ret;
  
  	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  	if (!priv)
  		return -ENOMEM;
  
  	priv->client.dev = dev;
  	priv->client.receive_cb = NULL;
  	priv->client.priv = priv;
  	priv->status.current_image = 0;
  	priv->status.fail_image = 0;
  	priv->status.error_location = 0;
  	priv->status.error_details = 0;
  	priv->status.version = 0;
  	priv->status.state = 0;
  	priv->retry_counter = INVALID_RETRY_COUNTER;

  	priv->dcmf_version.dcmf0 = INVALID_DCMF_VERSION;
  	priv->dcmf_version.dcmf1 = INVALID_DCMF_VERSION;
  	priv->dcmf_version.dcmf2 = INVALID_DCMF_VERSION;
  	priv->dcmf_version.dcmf3 = INVALID_DCMF_VERSION;
  	priv->max_retry = INVALID_RETRY_COUNTER;

  
  	mutex_init(&priv->lock);
  	priv->chan = stratix10_svc_request_channel_byname(&priv->client,
  							  SVC_CLIENT_RSU);
  	if (IS_ERR(priv->chan)) {
  		dev_err(dev, "couldn't get service channel %s
  ",
  			SVC_CLIENT_RSU);
  		return PTR_ERR(priv->chan);
  	}
  
  	init_completion(&priv->completion);
  	platform_set_drvdata(pdev, priv);
  
  	/* get the initial state from firmware */
  	ret = rsu_send_msg(priv, COMMAND_RSU_STATUS,
  			   0, rsu_status_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting RSU status %i
  ", ret);
  		stratix10_svc_free_channel(priv->chan);
  	}

  	/* get DCMF version from firmware */
  	ret = rsu_send_msg(priv, COMMAND_RSU_DCMF_VERSION,
  			   0, rsu_dcmf_version_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting DCMF version %i
  ", ret);
  		stratix10_svc_free_channel(priv->chan);
  	}

  	ret = rsu_send_msg(priv, COMMAND_RSU_RETRY, 0, rsu_retry_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting RSU retry %i
  ", ret);
  		stratix10_svc_free_channel(priv->chan);

  	}

  	ret = rsu_send_msg(priv, COMMAND_RSU_MAX_RETRY, 0,
  			   rsu_max_retry_callback);
  	if (ret) {
  		dev_err(dev, "Error, getting RSU max retry %i
  ", ret);
  		stratix10_svc_free_channel(priv->chan);
  	}

  	return ret;
  }
  
  static int stratix10_rsu_remove(struct platform_device *pdev)
  {
  	struct stratix10_rsu_priv *priv = platform_get_drvdata(pdev);
  
  	stratix10_svc_free_channel(priv->chan);
  	return 0;
  }
  
  static struct platform_driver stratix10_rsu_driver = {
  	.probe = stratix10_rsu_probe,
  	.remove = stratix10_rsu_remove,
  	.driver = {
  		.name = "stratix10-rsu",
  		.dev_groups = rsu_groups,
  	},
  };
  
  module_platform_driver(stratix10_rsu_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("Intel Remote System Update Driver");
  MODULE_AUTHOR("Richard Gong <richard.gong@intel.com>");