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

  /*
   * ST's Remote Processor Control Driver
   *
   * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
   *
   * Author: Ludovic Barre <ludovic.barre@st.com>

   */
  
  #include <linux/clk.h>
  #include <linux/dma-mapping.h>
  #include <linux/err.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>

  #include <linux/mailbox_client.h>

  #include <linux/mfd/syscon.h>
  #include <linux/module.h>
  #include <linux/of.h>

  #include <linux/of_address.h>

  #include <linux/of_device.h>
  #include <linux/of_reserved_mem.h>
  #include <linux/platform_device.h>
  #include <linux/regmap.h>
  #include <linux/remoteproc.h>
  #include <linux/reset.h>

  #include "remoteproc_internal.h"
  
  #define ST_RPROC_VQ0		0
  #define ST_RPROC_VQ1		1
  #define ST_RPROC_MAX_VRING	2
  
  #define MBOX_RX			0
  #define MBOX_TX			1
  #define MBOX_MAX		2

  struct st_rproc_config {
  	bool			sw_reset;
  	bool			pwr_reset;
  	unsigned long		bootaddr_mask;
  };
  
  struct st_rproc {
  	struct st_rproc_config	*config;
  	struct reset_control	*sw_reset;
  	struct reset_control	*pwr_reset;
  	struct clk		*clk;
  	u32			clk_rate;
  	struct regmap		*boot_base;
  	u32			boot_offset;

  	struct mbox_chan	*mbox_chan[ST_RPROC_MAX_VRING * MBOX_MAX];
  	struct mbox_client mbox_client_vq0;
  	struct mbox_client mbox_client_vq1;

  };

  static void st_rproc_mbox_callback(struct device *dev, u32 msg)
  {
  	struct rproc *rproc = dev_get_drvdata(dev);
  
  	if (rproc_vq_interrupt(rproc, msg) == IRQ_NONE)
  		dev_dbg(dev, "no message was found in vqid %d
  ", msg);
  }
  
  static
  void st_rproc_mbox_callback_vq0(struct mbox_client *mbox_client, void *data)
  {
  	st_rproc_mbox_callback(mbox_client->dev, 0);
  }
  
  static
  void st_rproc_mbox_callback_vq1(struct mbox_client *mbox_client, void *data)
  {
  	st_rproc_mbox_callback(mbox_client->dev, 1);
  }
  
  static void st_rproc_kick(struct rproc *rproc, int vqid)
  {
  	struct st_rproc *ddata = rproc->priv;
  	struct device *dev = rproc->dev.parent;
  	int ret;
  
  	/* send the index of the triggered virtqueue in the mailbox payload */
  	if (WARN_ON(vqid >= ST_RPROC_MAX_VRING))
  		return;
  
  	ret = mbox_send_message(ddata->mbox_chan[vqid * MBOX_MAX + MBOX_TX],
  				(void *)&vqid);
  	if (ret < 0)
  		dev_err(dev, "failed to send message via mbox: %d
  ", ret);
  }

  static int st_rproc_mem_alloc(struct rproc *rproc,
  			      struct rproc_mem_entry *mem)
  {
  	struct device *dev = rproc->dev.parent;
  	void *va;
  
  	va = ioremap_wc(mem->dma, mem->len);
  	if (!va) {
  		dev_err(dev, "Unable to map memory region: %pa+%zx
  ",
  			&mem->dma, mem->len);
  		return -ENOMEM;
  	}
  
  	/* Update memory entry va */
  	mem->va = va;
  
  	return 0;
  }
  
  static int st_rproc_mem_release(struct rproc *rproc,
  				struct rproc_mem_entry *mem)
  {
  	iounmap(mem->va);
  
  	return 0;
  }
  
  static int st_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
  {
  	struct device *dev = rproc->dev.parent;
  	struct device_node *np = dev->of_node;
  	struct rproc_mem_entry *mem;
  	struct reserved_mem *rmem;
  	struct of_phandle_iterator it;
  	int index = 0;
  
  	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
  	while (of_phandle_iterator_next(&it) == 0) {
  		rmem = of_reserved_mem_lookup(it.node);
  		if (!rmem) {
  			dev_err(dev, "unable to acquire memory-region
  ");
  			return -EINVAL;
  		}
  
  		/*  No need to map vdev buffer */
  		if (strcmp(it.node->name, "vdev0buffer")) {
  			/* Register memory region */
  			mem = rproc_mem_entry_init(dev, NULL,
  						   (dma_addr_t)rmem->base,
  						   rmem->size, rmem->base,
  						   st_rproc_mem_alloc,
  						   st_rproc_mem_release,
  						   it.node->name);
  		} else {
  			/* Register reserved memory for vdev buffer allocation */
  			mem = rproc_of_resm_mem_entry_init(dev, index,
  							   rmem->size,
  							   rmem->base,
  							   it.node->name);
  		}
  
  		if (!mem)
  			return -ENOMEM;
  
  		rproc_add_carveout(rproc, mem);
  		index++;
  	}
  
  	return rproc_elf_load_rsc_table(rproc, fw);
  }

  static int st_rproc_start(struct rproc *rproc)
  {
  	struct st_rproc *ddata = rproc->priv;
  	int err;
  
  	regmap_update_bits(ddata->boot_base, ddata->boot_offset,
  			   ddata->config->bootaddr_mask, rproc->bootaddr);
  
  	err = clk_enable(ddata->clk);
  	if (err) {
  		dev_err(&rproc->dev, "Failed to enable clock
  ");
  		return err;
  	}
  
  	if (ddata->config->sw_reset) {
  		err = reset_control_deassert(ddata->sw_reset);
  		if (err) {
  			dev_err(&rproc->dev, "Failed to deassert S/W Reset
  ");
  			goto sw_reset_fail;
  		}
  	}
  
  	if (ddata->config->pwr_reset) {
  		err = reset_control_deassert(ddata->pwr_reset);
  		if (err) {
  			dev_err(&rproc->dev, "Failed to deassert Power Reset
  ");
  			goto pwr_reset_fail;
  		}
  	}

  	dev_info(&rproc->dev, "Started from 0x%llx
  ", rproc->bootaddr);

  
  	return 0;
  
  
  pwr_reset_fail:
  	if (ddata->config->pwr_reset)
  		reset_control_assert(ddata->sw_reset);
  sw_reset_fail:
  	clk_disable(ddata->clk);
  
  	return err;
  }
  
  static int st_rproc_stop(struct rproc *rproc)
  {
  	struct st_rproc *ddata = rproc->priv;
  	int sw_err = 0, pwr_err = 0;
  
  	if (ddata->config->sw_reset) {
  		sw_err = reset_control_assert(ddata->sw_reset);
  		if (sw_err)
  			dev_err(&rproc->dev, "Failed to assert S/W Reset
  ");
  	}
  
  	if (ddata->config->pwr_reset) {
  		pwr_err = reset_control_assert(ddata->pwr_reset);
  		if (pwr_err)
  			dev_err(&rproc->dev, "Failed to assert Power Reset
  ");
  	}
  
  	clk_disable(ddata->clk);
  
  	return sw_err ?: pwr_err;
  }

  static const struct rproc_ops st_rproc_ops = {

  	.kick			= st_rproc_kick,
  	.start			= st_rproc_start,
  	.stop			= st_rproc_stop,
  	.parse_fw		= st_rproc_parse_fw,
  	.load			= rproc_elf_load_segments,
  	.find_loaded_rsc_table	= rproc_elf_find_loaded_rsc_table,

  	.sanity_check		= rproc_elf_sanity_check,

  	.get_boot_addr		= rproc_elf_get_boot_addr,

  };
  
  /*
   * Fetch state of the processor: 0 is off, 1 is on.
   */
  static int st_rproc_state(struct platform_device *pdev)
  {
  	struct rproc *rproc = platform_get_drvdata(pdev);
  	struct st_rproc *ddata = rproc->priv;
  	int reset_sw = 0, reset_pwr = 0;
  
  	if (ddata->config->sw_reset)
  		reset_sw = reset_control_status(ddata->sw_reset);
  
  	if (ddata->config->pwr_reset)
  		reset_pwr = reset_control_status(ddata->pwr_reset);
  
  	if (reset_sw < 0 || reset_pwr < 0)
  		return -EINVAL;
  
  	return !reset_sw && !reset_pwr;
  }
  
  static const struct st_rproc_config st40_rproc_cfg = {
  	.sw_reset = true,
  	.pwr_reset = true,
  	.bootaddr_mask = GENMASK(28, 1),
  };
  
  static const struct st_rproc_config st231_rproc_cfg = {
  	.sw_reset = true,
  	.pwr_reset = false,
  	.bootaddr_mask = GENMASK(31, 6),
  };
  
  static const struct of_device_id st_rproc_match[] = {
  	{ .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
  	{ .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
  	{},
  };
  MODULE_DEVICE_TABLE(of, st_rproc_match);
  
  static int st_rproc_parse_dt(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct rproc *rproc = platform_get_drvdata(pdev);
  	struct st_rproc *ddata = rproc->priv;
  	struct device_node *np = dev->of_node;
  	int err;
  
  	if (ddata->config->sw_reset) {

  		ddata->sw_reset = devm_reset_control_get_exclusive(dev,
  								   "sw_reset");

  		if (IS_ERR(ddata->sw_reset)) {
  			dev_err(dev, "Failed to get S/W Reset
  ");
  			return PTR_ERR(ddata->sw_reset);
  		}
  	}
  
  	if (ddata->config->pwr_reset) {

  		ddata->pwr_reset = devm_reset_control_get_exclusive(dev,
  								    "pwr_reset");

  		if (IS_ERR(ddata->pwr_reset)) {
  			dev_err(dev, "Failed to get Power Reset
  ");
  			return PTR_ERR(ddata->pwr_reset);
  		}
  	}
  
  	ddata->clk = devm_clk_get(dev, NULL);
  	if (IS_ERR(ddata->clk)) {
  		dev_err(dev, "Failed to get clock
  ");
  		return PTR_ERR(ddata->clk);
  	}
  
  	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
  	if (err) {
  		dev_err(dev, "failed to get clock frequency
  ");
  		return err;
  	}
  
  	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");

  	if (IS_ERR(ddata->boot_base)) {

  		dev_err(dev, "Boot base not found
  ");

  		return PTR_ERR(ddata->boot_base);

  	}
  
  	err = of_property_read_u32_index(np, "st,syscfg", 1,
  					 &ddata->boot_offset);
  	if (err) {
  		dev_err(dev, "Boot offset not found
  ");
  		return -EINVAL;
  	}

  	err = clk_prepare(ddata->clk);
  	if (err)
  		dev_err(dev, "failed to get clock
  ");
  
  	return err;
  }
  
  static int st_rproc_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	const struct of_device_id *match;
  	struct st_rproc *ddata;
  	struct device_node *np = dev->of_node;
  	struct rproc *rproc;

  	struct mbox_chan *chan;

  	int enabled;

  	int ret, i;

  
  	match = of_match_device(st_rproc_match, dev);
  	if (!match || !match->data) {
  		dev_err(dev, "No device match found
  ");
  		return -ENODEV;
  	}
  
  	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
  	if (!rproc)
  		return -ENOMEM;
  
  	rproc->has_iommu = false;
  	ddata = rproc->priv;
  	ddata->config = (struct st_rproc_config *)match->data;
  
  	platform_set_drvdata(pdev, rproc);
  
  	ret = st_rproc_parse_dt(pdev);
  	if (ret)
  		goto free_rproc;
  
  	enabled = st_rproc_state(pdev);

  	if (enabled < 0) {
  		ret = enabled;

  		goto free_clk;

  	}

  
  	if (enabled) {
  		atomic_inc(&rproc->power);
  		rproc->state = RPROC_RUNNING;
  	} else {
  		clk_set_rate(ddata->clk, ddata->clk_rate);
  	}

  	if (of_get_property(np, "mbox-names", NULL)) {
  		ddata->mbox_client_vq0.dev		= dev;
  		ddata->mbox_client_vq0.tx_done		= NULL;
  		ddata->mbox_client_vq0.tx_block	= false;
  		ddata->mbox_client_vq0.knows_txdone	= false;
  		ddata->mbox_client_vq0.rx_callback	= st_rproc_mbox_callback_vq0;
  
  		ddata->mbox_client_vq1.dev		= dev;
  		ddata->mbox_client_vq1.tx_done		= NULL;
  		ddata->mbox_client_vq1.tx_block	= false;
  		ddata->mbox_client_vq1.knows_txdone	= false;
  		ddata->mbox_client_vq1.rx_callback	= st_rproc_mbox_callback_vq1;
  
  		/*
  		 * To control a co-processor without IPC mechanism.
  		 * This driver can be used without mbox and rpmsg.
  		 */
  		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
  		if (IS_ERR(chan)) {
  			dev_err(&rproc->dev, "failed to request mbox chan 0
  ");
  			ret = PTR_ERR(chan);
  			goto free_clk;
  		}
  		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;
  
  		chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
  		if (IS_ERR(chan)) {
  			dev_err(&rproc->dev, "failed to request mbox chan 0
  ");
  			ret = PTR_ERR(chan);
  			goto free_mbox;
  		}
  		ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;
  
  		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
  		if (IS_ERR(chan)) {
  			dev_err(&rproc->dev, "failed to request mbox chan 1
  ");
  			ret = PTR_ERR(chan);
  			goto free_mbox;
  		}
  		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;
  
  		chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
  		if (IS_ERR(chan)) {
  			dev_err(&rproc->dev, "failed to request mbox chan 1
  ");
  			ret = PTR_ERR(chan);
  			goto free_mbox;
  		}
  		ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
  	}

  	ret = rproc_add(rproc);
  	if (ret)

  		goto free_mbox;

  
  	return 0;

  free_mbox:
  	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
  		mbox_free_channel(ddata->mbox_chan[i]);

  free_clk:
  	clk_unprepare(ddata->clk);

  free_rproc:

  	rproc_free(rproc);

  	return ret;
  }
  
  static int st_rproc_remove(struct platform_device *pdev)
  {
  	struct rproc *rproc = platform_get_drvdata(pdev);
  	struct st_rproc *ddata = rproc->priv;

  	int i;

  
  	rproc_del(rproc);
  
  	clk_disable_unprepare(ddata->clk);

  	for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
  		mbox_free_channel(ddata->mbox_chan[i]);

  	rproc_free(rproc);

  
  	return 0;
  }
  
  static struct platform_driver st_rproc_driver = {
  	.probe = st_rproc_probe,
  	.remove = st_rproc_remove,
  	.driver = {
  		.name = "st-rproc",
  		.of_match_table = of_match_ptr(st_rproc_match),
  	},
  };
  module_platform_driver(st_rproc_driver);
  
  MODULE_DESCRIPTION("ST Remote Processor Control Driver");
  MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
  MODULE_LICENSE("GPL v2");