/*
   * OMAP Remote Processor driver
   *
   * Copyright (C) 2011 Texas Instruments, Inc.
   * Copyright (C) 2011 Google, Inc.
   *
   * Ohad Ben-Cohen <ohad@wizery.com>
   * Brian Swetland <swetland@google.com>
   * Fernando Guzman Lugo <fernando.lugo@ti.com>
   * Mark Grosen <mgrosen@ti.com>
   * Suman Anna <s-anna@ti.com>
   * Hari Kanigeri <h-kanigeri2@ti.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * version 2 as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that 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/err.h>
  #include <linux/platform_device.h>
  #include <linux/dma-mapping.h>
  #include <linux/remoteproc.h>
  #include <linux/omap-mailbox.h>
  
  #include <linux/platform_data/remoteproc-omap.h>
  
  #include "omap_remoteproc.h"
  #include "remoteproc_internal.h"
  
  /**
   * struct omap_rproc - omap remote processor state
   * @mbox: omap mailbox handle
   * @nb: notifier block that will be invoked on inbound mailbox messages
   * @rproc: rproc handle
   */
  struct omap_rproc {
  	struct omap_mbox *mbox;
  	struct notifier_block nb;
  	struct rproc *rproc;
  };
  
  /**
   * omap_rproc_mbox_callback() - inbound mailbox message handler
   * @this: notifier block
   * @index: unused
   * @data: mailbox payload
   *
   * This handler is invoked by omap's mailbox driver whenever a mailbox
   * message is received. Usually, the mailbox payload simply contains
   * the index of the virtqueue that is kicked by the remote processor,
   * and we let remoteproc core handle it.
   *
   * In addition to virtqueue indices, we also have some out-of-band values
   * that indicates different events. Those values are deliberately very
   * big so they don't coincide with virtqueue indices.
   */
  static int omap_rproc_mbox_callback(struct notifier_block *this,
  					unsigned long index, void *data)
  {
  	mbox_msg_t msg = (mbox_msg_t) data;
  	struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb);
  	struct device *dev = oproc->rproc->dev.parent;
  	const char *name = oproc->rproc->name;
  
  	dev_dbg(dev, "mbox msg: 0x%x
  ", msg);
  
  	switch (msg) {
  	case RP_MBOX_CRASH:
  		/* just log this for now. later, we'll also do recovery */
  		dev_err(dev, "omap rproc %s crashed
  ", name);
  		break;
  	case RP_MBOX_ECHO_REPLY:
  		dev_info(dev, "received echo reply from %s
  ", name);
  		break;
  	default:
  		/* msg contains the index of the triggered vring */
  		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
  			dev_dbg(dev, "no message was found in vqid %d
  ", msg);
  	}
  
  	return NOTIFY_DONE;
  }
  
  /* kick a virtqueue */
  static void omap_rproc_kick(struct rproc *rproc, int vqid)
  {
  	struct omap_rproc *oproc = rproc->priv;
  	struct device *dev = rproc->dev.parent;
  	int ret;
  
  	/* send the index of the triggered virtqueue in the mailbox payload */
  	ret = omap_mbox_msg_send(oproc->mbox, vqid);
  	if (ret)
  		dev_err(dev, "omap_mbox_msg_send failed: %d
  ", ret);
  }
  
  /*
   * Power up the remote processor.
   *
   * This function will be invoked only after the firmware for this rproc
   * was loaded, parsed successfully, and all of its resource requirements
   * were met.
   */
  static int omap_rproc_start(struct rproc *rproc)
  {
  	struct omap_rproc *oproc = rproc->priv;
  	struct device *dev = rproc->dev.parent;
  	struct platform_device *pdev = to_platform_device(dev);
  	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
  	int ret;
  
  	if (pdata->set_bootaddr)
  		pdata->set_bootaddr(rproc->bootaddr);
  
  	oproc->nb.notifier_call = omap_rproc_mbox_callback;
  
  	/* every omap rproc is assigned a mailbox instance for messaging */
  	oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb);
  	if (IS_ERR(oproc->mbox)) {
  		ret = PTR_ERR(oproc->mbox);
  		dev_err(dev, "omap_mbox_get failed: %d
  ", ret);
  		return ret;
  	}
  
  	/*
  	 * Ping the remote processor. this is only for sanity-sake;
  	 * there is no functional effect whatsoever.
  	 *
  	 * Note that the reply will _not_ arrive immediately: this message
  	 * will wait in the mailbox fifo until the remote processor is booted.
  	 */
  	ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST);
  	if (ret) {
  		dev_err(dev, "omap_mbox_get failed: %d
  ", ret);
  		goto put_mbox;
  	}
  
  	ret = pdata->device_enable(pdev);
  	if (ret) {
  		dev_err(dev, "omap_device_enable failed: %d
  ", ret);
  		goto put_mbox;
  	}
  
  	return 0;
  
  put_mbox:
  	omap_mbox_put(oproc->mbox, &oproc->nb);
  	return ret;
  }
  
  /* power off the remote processor */
  static int omap_rproc_stop(struct rproc *rproc)
  {
  	struct device *dev = rproc->dev.parent;
  	struct platform_device *pdev = to_platform_device(dev);
  	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
  	struct omap_rproc *oproc = rproc->priv;
  	int ret;
  
  	ret = pdata->device_shutdown(pdev);
  	if (ret)
  		return ret;
  
  	omap_mbox_put(oproc->mbox, &oproc->nb);
  
  	return 0;
  }
  
  static struct rproc_ops omap_rproc_ops = {
  	.start		= omap_rproc_start,
  	.stop		= omap_rproc_stop,
  	.kick		= omap_rproc_kick,
  };
  
  static int omap_rproc_probe(struct platform_device *pdev)
  {
  	struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
  	struct omap_rproc *oproc;
  	struct rproc *rproc;
  	int ret;
  
  	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
  	if (ret) {
  		dev_err(&pdev->dev, "dma_set_coherent_mask: %d
  ", ret);
  		return ret;
  	}
  
  	rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops,
  				pdata->firmware, sizeof(*oproc));
  	if (!rproc)
  		return -ENOMEM;
  
  	oproc = rproc->priv;
  	oproc->rproc = rproc;
  
  	platform_set_drvdata(pdev, rproc);
  
  	ret = rproc_add(rproc);
  	if (ret)
  		goto free_rproc;
  
  	return 0;
  
  free_rproc:
  	rproc_put(rproc);
  	return ret;
  }
  
  static int omap_rproc_remove(struct platform_device *pdev)
  {
  	struct rproc *rproc = platform_get_drvdata(pdev);
  
  	rproc_del(rproc);
  	rproc_put(rproc);
  
  	return 0;
  }
  
  static struct platform_driver omap_rproc_driver = {
  	.probe = omap_rproc_probe,
  	.remove = omap_rproc_remove,
  	.driver = {
  		.name = "omap-rproc",
  		.owner = THIS_MODULE,
  	},
  };
  
  module_platform_driver(omap_rproc_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("OMAP Remote Processor control driver");