// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Remote Processor Framework

   */
  
  #include <linux/remoteproc.h>
  
  #include "remoteproc_internal.h"
  
  #define to_rproc(d) container_of(d, struct rproc, dev)
  
  /* Expose the loaded / running firmware name via sysfs */
  static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct rproc *rproc = to_rproc(dev);
  
  	return sprintf(buf, "%s
  ", rproc->firmware);
  }
  
  /* Change firmware name via sysfs */
  static ssize_t firmware_store(struct device *dev,
  			      struct device_attribute *attr,
  			      const char *buf, size_t count)
  {
  	struct rproc *rproc = to_rproc(dev);
  	char *p;
  	int err, len = count;
  
  	err = mutex_lock_interruptible(&rproc->lock);
  	if (err) {
  		dev_err(dev, "can't lock rproc %s: %d
  ", rproc->name, err);
  		return -EINVAL;
  	}
  
  	if (rproc->state != RPROC_OFFLINE) {
  		dev_err(dev, "can't change firmware while running
  ");
  		err = -EBUSY;
  		goto out;
  	}
  
  	len = strcspn(buf, "
  ");

  	if (!len) {
  		dev_err(dev, "can't provide a NULL firmware
  ");
  		err = -EINVAL;
  		goto out;
  	}

  
  	p = kstrndup(buf, len, GFP_KERNEL);
  	if (!p) {
  		err = -ENOMEM;
  		goto out;
  	}
  
  	kfree(rproc->firmware);
  	rproc->firmware = p;
  out:
  	mutex_unlock(&rproc->lock);
  
  	return err ? err : count;
  }
  static DEVICE_ATTR_RW(firmware);
  
  /*
   * A state-to-string lookup table, for exposing a human readable state
   * via sysfs. Always keep in sync with enum rproc_state
   */
  static const char * const rproc_state_string[] = {
  	[RPROC_OFFLINE]		= "offline",
  	[RPROC_SUSPENDED]	= "suspended",
  	[RPROC_RUNNING]		= "running",
  	[RPROC_CRASHED]		= "crashed",

  	[RPROC_DELETED]		= "deleted",

  	[RPROC_LAST]		= "invalid",
  };
  
  /* Expose the state of the remote processor via sysfs */
  static ssize_t state_show(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct rproc *rproc = to_rproc(dev);
  	unsigned int state;
  
  	state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
  	return sprintf(buf, "%s
  ", rproc_state_string[state]);
  }
  
  /* Change remote processor state via sysfs */
  static ssize_t state_store(struct device *dev,
  			      struct device_attribute *attr,
  			      const char *buf, size_t count)
  {
  	struct rproc *rproc = to_rproc(dev);
  	int ret = 0;
  
  	if (sysfs_streq(buf, "start")) {
  		if (rproc->state == RPROC_RUNNING)
  			return -EBUSY;
  
  		ret = rproc_boot(rproc);
  		if (ret)
  			dev_err(&rproc->dev, "Boot failed: %d
  ", ret);
  	} else if (sysfs_streq(buf, "stop")) {
  		if (rproc->state != RPROC_RUNNING)
  			return -EINVAL;
  
  		rproc_shutdown(rproc);
  	} else {
  		dev_err(&rproc->dev, "Unrecognised option: %s
  ", buf);
  		ret = -EINVAL;
  	}
  	return ret ? ret : count;
  }
  static DEVICE_ATTR_RW(state);

  /* Expose the name of the remote processor via sysfs */
  static ssize_t name_show(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct rproc *rproc = to_rproc(dev);
  
  	return sprintf(buf, "%s
  ", rproc->name);
  }
  static DEVICE_ATTR_RO(name);

  static struct attribute *rproc_attrs[] = {
  	&dev_attr_firmware.attr,
  	&dev_attr_state.attr,

  	&dev_attr_name.attr,

  	NULL
  };
  
  static const struct attribute_group rproc_devgroup = {
  	.attrs = rproc_attrs
  };
  
  static const struct attribute_group *rproc_devgroups[] = {
  	&rproc_devgroup,
  	NULL
  };
  
  struct class rproc_class = {
  	.name		= "remoteproc",
  	.dev_groups	= rproc_devgroups,
  };
  
  int __init rproc_init_sysfs(void)
  {
  	/* create remoteproc device class for sysfs */
  	int err = class_register(&rproc_class);
  
  	if (err)
  		pr_err("remoteproc: unable to register class
  ");
  	return err;
  }
  
  void __exit rproc_exit_sysfs(void)
  {
  	class_unregister(&rproc_class);
  }