drivers/remoteproc/keystone_remoteproc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * TI Keystone DSP remoteproc driver
  *
  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
  */

 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/workqueue.h>
 #include <linux/of_address.h>
 #include <linux/of_reserved_mem.h>
 #include <linux/gpio/consumer.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
 #include <linux/remoteproc.h>
 #include <linux/reset.h>

 #include "remoteproc_internal.h"

 #define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK	(SZ_16M - 1)

 /**
  * struct keystone_rproc_mem - internal memory structure
  * @cpu_addr: MPU virtual address of the memory region
  * @bus_addr: Bus address used to access the memory region
  * @dev_addr: Device address of the memory region from DSP view
  * @size: Size of the memory region
  */
 struct keystone_rproc_mem {
 	void __iomem *cpu_addr;
 	phys_addr_t bus_addr;
 	u32 dev_addr;
 	size_t size;
 };

 /**
  * struct keystone_rproc - keystone remote processor driver structure
  * @dev: cached device pointer
  * @rproc: remoteproc device handle
  * @mem: internal memory regions data
  * @num_mems: number of internal memory regions
  * @dev_ctrl: device control regmap handle
  * @reset: reset control handle
  * @boot_offset: boot register offset in @dev_ctrl regmap
  * @irq_ring: irq entry for vring
  * @irq_fault: irq entry for exception
  * @kick_gpio: gpio used for virtio kicks
  * @workqueue: workqueue for processing virtio interrupts
  */
 struct keystone_rproc {
 	struct device *dev;
 	struct rproc *rproc;
 	struct keystone_rproc_mem *mem;
 	int num_mems;
 	struct regmap *dev_ctrl;
 	struct reset_control *reset;
 	struct gpio_desc *kick_gpio;
 	u32 boot_offset;
 	int irq_ring;
 	int irq_fault;
 	struct work_struct workqueue;
 };

 /* Put the DSP processor into reset */
 static void keystone_rproc_dsp_reset(struct keystone_rproc *ksproc)
 {
 	reset_control_assert(ksproc->reset);
 }

 /* Configure the boot address and boot the DSP processor */
 static int keystone_rproc_dsp_boot(struct keystone_rproc *ksproc, u32 boot_addr)
 {
 	int ret;

 	if (boot_addr & (SZ_1K - 1)) {
 		dev_err(ksproc->dev, "invalid boot address 0x%x, must be aligned on a 1KB boundary\n",
 			boot_addr);
 		return -EINVAL;
 	}

 	ret = regmap_write(ksproc->dev_ctrl, ksproc->boot_offset, boot_addr);
 	if (ret) {
 		dev_err(ksproc->dev, "regmap_write of boot address failed, status = %d\n",
 			ret);
 		return ret;
 	}

 	reset_control_deassert(ksproc->reset);

 	return 0;
 }

 /*
  * Process the remoteproc exceptions
  *
  * The exception reporting on Keystone DSP remote processors is very simple
  * compared to the equivalent processors on the OMAP family, it is notified
  * through a software-designed specific interrupt source in the IPC interrupt
  * generation register.
  *
  * This function just invokes the rproc_report_crash to report the exception
  * to the remoteproc driver core, to trigger a recovery.
  */
 static irqreturn_t keystone_rproc_exception_interrupt(int irq, void *dev_id)
 {
 	struct keystone_rproc *ksproc = dev_id;

 	rproc_report_crash(ksproc->rproc, RPROC_FATAL_ERROR);

 	return IRQ_HANDLED;
 }

 /*
  * Main virtqueue message workqueue function
  *
  * This function is executed upon scheduling of the keystone remoteproc
  * driver's workqueue. The workqueue is scheduled by the vring ISR handler.
  *
  * There is no payload message indicating the virtqueue index as is the
  * case with mailbox-based implementations on OMAP family. As such, this
  * handler processes both the Tx and Rx virtqueue indices on every invocation.
  * The rproc_vq_interrupt function can detect if there are new unprocessed
  * messages or not (returns IRQ_NONE vs IRQ_HANDLED), but there is no need
  * to check for these return values. The index 0 triggering will process all
  * pending Rx buffers, and the index 1 triggering will process all newly
  * available Tx buffers and will wakeup any potentially blocked senders.
  *
  * NOTE:
  * 1. A payload could be added by using some of the source bits in the
  *    IPC interrupt generation registers, but this would need additional
  *    changes to the overall IPC stack, and currently there are no benefits
  *    of adapting that approach.
  * 2. The current logic is based on an inherent design assumption of supporting
  *    only 2 vrings, but this can be changed if needed.
  */
 static void handle_event(struct work_struct *work)
 {
 	struct keystone_rproc *ksproc =
 		container_of(work, struct keystone_rproc, workqueue);

 	rproc_vq_interrupt(ksproc->rproc, 0);
 	rproc_vq_interrupt(ksproc->rproc, 1);
 }

 /*
  * Interrupt handler for processing vring kicks from remote processor
  */
 static irqreturn_t keystone_rproc_vring_interrupt(int irq, void *dev_id)
 {
 	struct keystone_rproc *ksproc = dev_id;

 	schedule_work(&ksproc->workqueue);

 	return IRQ_HANDLED;
 }

 /*
  * Power up the DSP 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 keystone_rproc_start(struct rproc *rproc)
 {
 	struct keystone_rproc *ksproc = rproc->priv;
 	int ret;

 	INIT_WORK(&ksproc->workqueue, handle_event);

 	ret = request_irq(ksproc->irq_ring, keystone_rproc_vring_interrupt, 0,
 			  dev_name(ksproc->dev), ksproc);
 	if (ret) {
 		dev_err(ksproc->dev, "failed to enable vring interrupt, ret = %d\n",
 			ret);
 		goto out;
 	}

 	ret = request_irq(ksproc->irq_fault, keystone_rproc_exception_interrupt,
 			  0, dev_name(ksproc->dev), ksproc);
 	if (ret) {
 		dev_err(ksproc->dev, "failed to enable exception interrupt, ret = %d\n",
 			ret);
 		goto free_vring_irq;
 	}

 	ret = keystone_rproc_dsp_boot(ksproc, rproc->bootaddr);
 	if (ret)
 		goto free_exc_irq;

 	return 0;

 free_exc_irq:
 	free_irq(ksproc->irq_fault, ksproc);
 free_vring_irq:
 	free_irq(ksproc->irq_ring, ksproc);
 	flush_work(&ksproc->workqueue);
 out:
 	return ret;
 }

 /*
  * Stop the DSP remote processor.
  *
  * This function puts the DSP processor into reset, and finishes processing
  * of any pending messages.
  */
 static int keystone_rproc_stop(struct rproc *rproc)
 {
 	struct keystone_rproc *ksproc = rproc->priv;

 	keystone_rproc_dsp_reset(ksproc);
 	free_irq(ksproc->irq_fault, ksproc);
 	free_irq(ksproc->irq_ring, ksproc);
 	flush_work(&ksproc->workqueue);

 	return 0;
 }

 /*
  * Kick the remote processor to notify about pending unprocessed messages.
  * The vqid usage is not used and is inconsequential, as the kick is performed
  * through a simulated GPIO (a bit in an IPC interrupt-triggering register),
  * the remote processor is expected to process both its Tx and Rx virtqueues.
  */
 static void keystone_rproc_kick(struct rproc *rproc, int vqid)
 {
 	struct keystone_rproc *ksproc = rproc->priv;

 	if (!ksproc->kick_gpio)
 		return;

 	gpiod_set_value(ksproc->kick_gpio, 1);
 }

 /*
  * Custom function to translate a DSP device address (internal RAMs only) to a
  * kernel virtual address.  The DSPs can access their RAMs at either an internal
  * address visible only from a DSP, or at the SoC-level bus address. Both these
  * addresses need to be looked through for translation. The translated addresses
  * can be used either by the remoteproc core for loading (when using kernel
  * remoteproc loader), or by any rpmsg bus drivers.
  */
 static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
 {
 	struct keystone_rproc *ksproc = rproc->priv;
 	void __iomem *va = NULL;
 	phys_addr_t bus_addr;
 	u32 dev_addr, offset;
 	size_t size;
 	int i;

 	if (len == 0)
 		return NULL;

 	for (i = 0; i < ksproc->num_mems; i++) {
 		bus_addr = ksproc->mem[i].bus_addr;
 		dev_addr = ksproc->mem[i].dev_addr;
 		size = ksproc->mem[i].size;

 		if (da < KEYSTONE_RPROC_LOCAL_ADDRESS_MASK) {
 			/* handle DSP-view addresses */
 			if ((da >= dev_addr) &&
 			    ((da + len) <= (dev_addr + size))) {
 				offset = da - dev_addr;
 				va = ksproc->mem[i].cpu_addr + offset;
 				break;
 			}
 		} else {
 			/* handle SoC-view addresses */
 			if ((da >= bus_addr) &&
 			    (da + len) <= (bus_addr + size)) {
 				offset = da - bus_addr;
 				va = ksproc->mem[i].cpu_addr + offset;
 				break;
 			}
 		}
 	}

 	return (__force void *)va;
 }

 static const struct rproc_ops keystone_rproc_ops = {
 	.start		= keystone_rproc_start,
 	.stop		= keystone_rproc_stop,
 	.kick		= keystone_rproc_kick,
 	.da_to_va	= keystone_rproc_da_to_va,
 };

 static int keystone_rproc_of_get_memories(struct platform_device *pdev,
 					  struct keystone_rproc *ksproc)
 {
 	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
 	struct device *dev = &pdev->dev;
 	struct resource *res;
 	int num_mems = 0;
 	int i;

 	num_mems = ARRAY_SIZE(mem_names);
 	ksproc->mem = devm_kcalloc(ksproc->dev, num_mems,
 				   sizeof(*ksproc->mem), GFP_KERNEL);
 	if (!ksproc->mem)
 		return -ENOMEM;

 	for (i = 0; i < num_mems; i++) {
 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 						   mem_names[i]);
 		ksproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
 		if (IS_ERR(ksproc->mem[i].cpu_addr)) {
 			dev_err(dev, "failed to parse and map %s memory\n",
 				mem_names[i]);
 			return PTR_ERR(ksproc->mem[i].cpu_addr);
 		}
 		ksproc->mem[i].bus_addr = res->start;
 		ksproc->mem[i].dev_addr =
 				res->start & KEYSTONE_RPROC_LOCAL_ADDRESS_MASK;
 		ksproc->mem[i].size = resource_size(res);

 		/* zero out memories to start in a pristine state */
 		memset((__force void *)ksproc->mem[i].cpu_addr, 0,
 		       ksproc->mem[i].size);
 	}
 	ksproc->num_mems = num_mems;

 	return 0;
 }

 static int keystone_rproc_of_get_dev_syscon(struct platform_device *pdev,
 					    struct keystone_rproc *ksproc)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
 	int ret;

 	if (!of_property_read_bool(np, "ti,syscon-dev")) {
 		dev_err(dev, "ti,syscon-dev property is absent\n");
 		return -EINVAL;
 	}

 	ksproc->dev_ctrl =
 		syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
 	if (IS_ERR(ksproc->dev_ctrl)) {
 		ret = PTR_ERR(ksproc->dev_ctrl);
 		return ret;
 	}

 	if (of_property_read_u32_index(np, "ti,syscon-dev", 1,
 				       &ksproc->boot_offset)) {
 		dev_err(dev, "couldn't read the boot register offset\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 static int keystone_rproc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct keystone_rproc *ksproc;
 	struct rproc *rproc;
 	int dsp_id;
 	char *fw_name = NULL;
 	int ret = 0;

 	if (!np) {
 		dev_err(dev, "only DT-based devices are supported\n");
 		return -ENODEV;
 	}

 	dsp_id = of_alias_get_id(np, "rproc");
 	if (dsp_id < 0) {
 		dev_warn(dev, "device does not have an alias id\n");
 		return dsp_id;
 	}

 	/* construct a custom default fw name - subject to change in future */
 	fw_name = devm_kasprintf(dev, GFP_KERNEL, "keystone-dsp%d-fw", dsp_id);
 	if (!fw_name)
 		return -ENOMEM;

 	rproc = devm_rproc_alloc(dev, dev_name(dev), &keystone_rproc_ops,
 				 fw_name, sizeof(*ksproc));
 	if (!rproc)
 		return -ENOMEM;

 	rproc->has_iommu = false;
 	ksproc = rproc->priv;
 	ksproc->rproc = rproc;
 	ksproc->dev = dev;

 	ret = keystone_rproc_of_get_dev_syscon(pdev, ksproc);
 	if (ret)
 		return ret;

 	ksproc->reset = devm_reset_control_get_exclusive(dev, NULL);
 	if (IS_ERR(ksproc->reset))
 		return PTR_ERR(ksproc->reset);

 	/* enable clock for accessing DSP internal memories */
 	pm_runtime_enable(dev);
 	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0) {
 		dev_err(dev, "failed to enable clock, status = %d\n", ret);
 		goto disable_rpm;
 	}

 	ret = keystone_rproc_of_get_memories(pdev, ksproc);
 	if (ret)
 		goto disable_clk;

 	ksproc->irq_ring = platform_get_irq_byname(pdev, "vring");
 	if (ksproc->irq_ring < 0) {
 		ret = ksproc->irq_ring;
 		goto disable_clk;
 	}

 	ksproc->irq_fault = platform_get_irq_byname(pdev, "exception");
 	if (ksproc->irq_fault < 0) {
 		ret = ksproc->irq_fault;
 		goto disable_clk;
 	}

 	ksproc->kick_gpio = gpiod_get(dev, "kick", GPIOD_ASIS);
 	ret = PTR_ERR_OR_ZERO(ksproc->kick_gpio);
 	if (ret) {
 		dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
 			ret);
 		goto disable_clk;
 	}

 	if (of_reserved_mem_device_init(dev))
 		dev_warn(dev, "device does not have specific CMA pool\n");

 	/* ensure the DSP is in reset before loading firmware */
 	ret = reset_control_status(ksproc->reset);
 	if (ret < 0) {
 		dev_err(dev, "failed to get reset status, status = %d\n", ret);
 		goto release_mem;
 	} else if (ret == 0) {
 		WARN(1, "device is not in reset\n");
 		keystone_rproc_dsp_reset(ksproc);
 	}

 	ret = rproc_add(rproc);
 	if (ret) {
 		dev_err(dev, "failed to add register device with remoteproc core, status = %d\n",
 			ret);
 		goto release_mem;
 	}

 	platform_set_drvdata(pdev, ksproc);

 	return 0;

 release_mem:
 	of_reserved_mem_device_release(dev);
 	gpiod_put(ksproc->kick_gpio);
 disable_clk:
 	pm_runtime_put_sync(dev);
 disable_rpm:
 	pm_runtime_disable(dev);
 	return ret;
 }

 static void keystone_rproc_remove(struct platform_device *pdev)
 {
 	struct keystone_rproc *ksproc = platform_get_drvdata(pdev);

 	rproc_del(ksproc->rproc);
 	gpiod_put(ksproc->kick_gpio);
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	of_reserved_mem_device_release(&pdev->dev);
 }

 static const struct of_device_id keystone_rproc_of_match[] = {
 	{ .compatible = "ti,k2hk-dsp", },
 	{ .compatible = "ti,k2l-dsp", },
 	{ .compatible = "ti,k2e-dsp", },
 	{ .compatible = "ti,k2g-dsp", },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);

 static struct platform_driver keystone_rproc_driver = {
 	.probe	= keystone_rproc_probe,
 	.remove_new = keystone_rproc_remove,
 	.driver	= {
 		.name = "keystone-rproc",
 		.of_match_table = keystone_rproc_of_match,
 	},
 };

 module_platform_driver(keystone_rproc_driver);

 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* TI Keystone DSP remoteproc driver
	*
	* Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
	*/

	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/io.h>
	#include <linux/interrupt.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/workqueue.h>
	#include <linux/of_address.h>
	#include <linux/of_reserved_mem.h>
	#include <linux/gpio/consumer.h>
	#include <linux/regmap.h>
	#include <linux/mfd/syscon.h>
	#include <linux/remoteproc.h>
	#include <linux/reset.h>

	#include "remoteproc_internal.h"

	#define KEYSTONE_RPROC_LOCAL_ADDRESS_MASK (SZ_16M - 1)

	/**
	* struct keystone_rproc_mem - internal memory structure
	* @cpu_addr: MPU virtual address of the memory region
	* @bus_addr: Bus address used to access the memory region
	* @dev_addr: Device address of the memory region from DSP view
	* @size: Size of the memory region
	*/
	struct keystone_rproc_mem {
	void __iomem *cpu_addr;
	phys_addr_t bus_addr;
	u32 dev_addr;
	size_t size;
	};

	/**
	* struct keystone_rproc - keystone remote processor driver structure
	* @dev: cached device pointer
	* @rproc: remoteproc device handle
	* @mem: internal memory regions data
	* @num_mems: number of internal memory regions
	* @dev_ctrl: device control regmap handle
	* @reset: reset control handle
	* @boot_offset: boot register offset in @dev_ctrl regmap
	* @irq_ring: irq entry for vring
	* @irq_fault: irq entry for exception
	* @kick_gpio: gpio used for virtio kicks
	* @workqueue: workqueue for processing virtio interrupts
	*/
	struct keystone_rproc {
	struct device *dev;
	struct rproc *rproc;
	struct keystone_rproc_mem *mem;
	int num_mems;
	struct regmap *dev_ctrl;
	struct reset_control *reset;
	struct gpio_desc *kick_gpio;
	u32 boot_offset;
	int irq_ring;
	int irq_fault;
	struct work_struct workqueue;
	};

	/* Put the DSP processor into reset */
	static void keystone_rproc_dsp_reset(struct keystone_rproc *ksproc)
	{
	reset_control_assert(ksproc->reset);
	}

	/* Configure the boot address and boot the DSP processor */
	static int keystone_rproc_dsp_boot(struct keystone_rproc *ksproc, u32 boot_addr)
	{
	int ret;

	if (boot_addr & (SZ_1K - 1)) {
	dev_err(ksproc->dev, "invalid boot address 0x%x, must be aligned on a 1KB boundary\n",
	boot_addr);
	return -EINVAL;
	}

	ret = regmap_write(ksproc->dev_ctrl, ksproc->boot_offset, boot_addr);
	if (ret) {
	dev_err(ksproc->dev, "regmap_write of boot address failed, status = %d\n",
	ret);
	return ret;
	}

	reset_control_deassert(ksproc->reset);

	return 0;
	}

	/*
	* Process the remoteproc exceptions
	*
	* The exception reporting on Keystone DSP remote processors is very simple
	* compared to the equivalent processors on the OMAP family, it is notified
	* through a software-designed specific interrupt source in the IPC interrupt
	* generation register.
	*
	* This function just invokes the rproc_report_crash to report the exception
	* to the remoteproc driver core, to trigger a recovery.
	*/
	static irqreturn_t keystone_rproc_exception_interrupt(int irq, void *dev_id)
	{
	struct keystone_rproc *ksproc = dev_id;

	rproc_report_crash(ksproc->rproc, RPROC_FATAL_ERROR);

	return IRQ_HANDLED;
	}

	/*
	* Main virtqueue message workqueue function
	*
	* This function is executed upon scheduling of the keystone remoteproc
	* driver's workqueue. The workqueue is scheduled by the vring ISR handler.
	*
	* There is no payload message indicating the virtqueue index as is the
	* case with mailbox-based implementations on OMAP family. As such, this
	* handler processes both the Tx and Rx virtqueue indices on every invocation.
	* The rproc_vq_interrupt function can detect if there are new unprocessed
	* messages or not (returns IRQ_NONE vs IRQ_HANDLED), but there is no need
	* to check for these return values. The index 0 triggering will process all
	* pending Rx buffers, and the index 1 triggering will process all newly
	* available Tx buffers and will wakeup any potentially blocked senders.
	*
	* NOTE:
	* 1. A payload could be added by using some of the source bits in the
	* IPC interrupt generation registers, but this would need additional
	* changes to the overall IPC stack, and currently there are no benefits
	* of adapting that approach.
	* 2. The current logic is based on an inherent design assumption of supporting
	* only 2 vrings, but this can be changed if needed.
	*/
	static void handle_event(struct work_struct *work)
	{
	struct keystone_rproc *ksproc =
	container_of(work, struct keystone_rproc, workqueue);

	rproc_vq_interrupt(ksproc->rproc, 0);
	rproc_vq_interrupt(ksproc->rproc, 1);
	}

	/*
	* Interrupt handler for processing vring kicks from remote processor
	*/
	static irqreturn_t keystone_rproc_vring_interrupt(int irq, void *dev_id)
	{
	struct keystone_rproc *ksproc = dev_id;

	schedule_work(&ksproc->workqueue);

	return IRQ_HANDLED;
	}

	/*
	* Power up the DSP 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 keystone_rproc_start(struct rproc *rproc)
	{
	struct keystone_rproc *ksproc = rproc->priv;
	int ret;

	INIT_WORK(&ksproc->workqueue, handle_event);

	ret = request_irq(ksproc->irq_ring, keystone_rproc_vring_interrupt, 0,
	dev_name(ksproc->dev), ksproc);
	if (ret) {
	dev_err(ksproc->dev, "failed to enable vring interrupt, ret = %d\n",
	ret);
	goto out;
	}

	ret = request_irq(ksproc->irq_fault, keystone_rproc_exception_interrupt,
	0, dev_name(ksproc->dev), ksproc);
	if (ret) {
	dev_err(ksproc->dev, "failed to enable exception interrupt, ret = %d\n",
	ret);
	goto free_vring_irq;
	}

	ret = keystone_rproc_dsp_boot(ksproc, rproc->bootaddr);
	if (ret)
	goto free_exc_irq;

	return 0;

	free_exc_irq:
	free_irq(ksproc->irq_fault, ksproc);
	free_vring_irq:
	free_irq(ksproc->irq_ring, ksproc);
	flush_work(&ksproc->workqueue);
	out:
	return ret;
	}

	/*
	* Stop the DSP remote processor.
	*
	* This function puts the DSP processor into reset, and finishes processing
	* of any pending messages.
	*/
	static int keystone_rproc_stop(struct rproc *rproc)
	{
	struct keystone_rproc *ksproc = rproc->priv;

	keystone_rproc_dsp_reset(ksproc);
	free_irq(ksproc->irq_fault, ksproc);
	free_irq(ksproc->irq_ring, ksproc);
	flush_work(&ksproc->workqueue);

	return 0;
	}

	/*
	* Kick the remote processor to notify about pending unprocessed messages.
	* The vqid usage is not used and is inconsequential, as the kick is performed
	* through a simulated GPIO (a bit in an IPC interrupt-triggering register),
	* the remote processor is expected to process both its Tx and Rx virtqueues.
	*/
	static void keystone_rproc_kick(struct rproc *rproc, int vqid)
	{
	struct keystone_rproc *ksproc = rproc->priv;

	if (!ksproc->kick_gpio)
	return;

	gpiod_set_value(ksproc->kick_gpio, 1);
	}

	/*
	* Custom function to translate a DSP device address (internal RAMs only) to a
	* kernel virtual address. The DSPs can access their RAMs at either an internal
	* address visible only from a DSP, or at the SoC-level bus address. Both these
	* addresses need to be looked through for translation. The translated addresses
	* can be used either by the remoteproc core for loading (when using kernel
	* remoteproc loader), or by any rpmsg bus drivers.
	*/
	static void keystone_rproc_da_to_va(struct rproc rproc, u64 da, size_t len, bool *is_iomem)
	{
	struct keystone_rproc *ksproc = rproc->priv;
	void __iomem *va = NULL;
	phys_addr_t bus_addr;
	u32 dev_addr, offset;
	size_t size;
	int i;

	if (len == 0)
	return NULL;

	for (i = 0; i < ksproc->num_mems; i++) {
	bus_addr = ksproc->mem[i].bus_addr;
	dev_addr = ksproc->mem[i].dev_addr;
	size = ksproc->mem[i].size;

	if (da < KEYSTONE_RPROC_LOCAL_ADDRESS_MASK) {
	/* handle DSP-view addresses */
	if ((da >= dev_addr) &&
	((da + len) <= (dev_addr + size))) {
	offset = da - dev_addr;
	va = ksproc->mem[i].cpu_addr + offset;
	break;
	}
	} else {
	/* handle SoC-view addresses */
	if ((da >= bus_addr) &&
	(da + len) <= (bus_addr + size)) {
	offset = da - bus_addr;
	va = ksproc->mem[i].cpu_addr + offset;
	break;
	}
	}
	}

	return (__force void *)va;
	}

	static const struct rproc_ops keystone_rproc_ops = {
	.start = keystone_rproc_start,
	.stop = keystone_rproc_stop,
	.kick = keystone_rproc_kick,
	.da_to_va = keystone_rproc_da_to_va,
	};

	static int keystone_rproc_of_get_memories(struct platform_device *pdev,
	struct keystone_rproc *ksproc)
	{
	static const char * const mem_names[] = {"l2sram", "l1pram", "l1dram"};
	struct device *dev = &pdev->dev;
	struct resource *res;
	int num_mems = 0;
	int i;

	num_mems = ARRAY_SIZE(mem_names);
	ksproc->mem = devm_kcalloc(ksproc->dev, num_mems,
	sizeof(*ksproc->mem), GFP_KERNEL);
	if (!ksproc->mem)
	return -ENOMEM;

	for (i = 0; i < num_mems; i++) {
	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
	mem_names[i]);
	ksproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
	if (IS_ERR(ksproc->mem[i].cpu_addr)) {
	dev_err(dev, "failed to parse and map %s memory\n",
	mem_names[i]);
	return PTR_ERR(ksproc->mem[i].cpu_addr);
	}
	ksproc->mem[i].bus_addr = res->start;
	ksproc->mem[i].dev_addr =
	res->start & KEYSTONE_RPROC_LOCAL_ADDRESS_MASK;
	ksproc->mem[i].size = resource_size(res);

	/* zero out memories to start in a pristine state */
	memset((__force void *)ksproc->mem[i].cpu_addr, 0,
	ksproc->mem[i].size);
	}
	ksproc->num_mems = num_mems;

	return 0;
	}

	static int keystone_rproc_of_get_dev_syscon(struct platform_device *pdev,
	struct keystone_rproc *ksproc)
	{
	struct device_node *np = pdev->dev.of_node;
	struct device *dev = &pdev->dev;
	int ret;

	if (!of_property_read_bool(np, "ti,syscon-dev")) {
	dev_err(dev, "ti,syscon-dev property is absent\n");
	return -EINVAL;
	}

	ksproc->dev_ctrl =
	syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
	if (IS_ERR(ksproc->dev_ctrl)) {
	ret = PTR_ERR(ksproc->dev_ctrl);
	return ret;
	}

	if (of_property_read_u32_index(np, "ti,syscon-dev", 1,
	&ksproc->boot_offset)) {
	dev_err(dev, "couldn't read the boot register offset\n");
	return -EINVAL;
	}

	return 0;
	}

	static int keystone_rproc_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct keystone_rproc *ksproc;
	struct rproc *rproc;
	int dsp_id;
	char *fw_name = NULL;
	int ret = 0;

	if (!np) {
	dev_err(dev, "only DT-based devices are supported\n");
	return -ENODEV;
	}

	dsp_id = of_alias_get_id(np, "rproc");
	if (dsp_id < 0) {
	dev_warn(dev, "device does not have an alias id\n");
	return dsp_id;
	}

	/* construct a custom default fw name - subject to change in future */
	fw_name = devm_kasprintf(dev, GFP_KERNEL, "keystone-dsp%d-fw", dsp_id);
	if (!fw_name)
	return -ENOMEM;

	rproc = devm_rproc_alloc(dev, dev_name(dev), &keystone_rproc_ops,
	fw_name, sizeof(*ksproc));
	if (!rproc)
	return -ENOMEM;

	rproc->has_iommu = false;
	ksproc = rproc->priv;
	ksproc->rproc = rproc;
	ksproc->dev = dev;

	ret = keystone_rproc_of_get_dev_syscon(pdev, ksproc);
	if (ret)
	return ret;

	ksproc->reset = devm_reset_control_get_exclusive(dev, NULL);
	if (IS_ERR(ksproc->reset))
	return PTR_ERR(ksproc->reset);

	/* enable clock for accessing DSP internal memories */
	pm_runtime_enable(dev);
	ret = pm_runtime_resume_and_get(dev);
	if (ret < 0) {
	dev_err(dev, "failed to enable clock, status = %d\n", ret);
	goto disable_rpm;
	}

	ret = keystone_rproc_of_get_memories(pdev, ksproc);
	if (ret)
	goto disable_clk;

	ksproc->irq_ring = platform_get_irq_byname(pdev, "vring");
	if (ksproc->irq_ring < 0) {
	ret = ksproc->irq_ring;
	goto disable_clk;
	}

	ksproc->irq_fault = platform_get_irq_byname(pdev, "exception");
	if (ksproc->irq_fault < 0) {
	ret = ksproc->irq_fault;
	goto disable_clk;
	}

	ksproc->kick_gpio = gpiod_get(dev, "kick", GPIOD_ASIS);
	ret = PTR_ERR_OR_ZERO(ksproc->kick_gpio);
	if (ret) {
	dev_err(dev, "failed to get gpio for virtio kicks, status = %d\n",
	ret);
	goto disable_clk;
	}

	if (of_reserved_mem_device_init(dev))
	dev_warn(dev, "device does not have specific CMA pool\n");

	/* ensure the DSP is in reset before loading firmware */
	ret = reset_control_status(ksproc->reset);
	if (ret < 0) {
	dev_err(dev, "failed to get reset status, status = %d\n", ret);
	goto release_mem;
	} else if (ret == 0) {
	WARN(1, "device is not in reset\n");
	keystone_rproc_dsp_reset(ksproc);
	}

	ret = rproc_add(rproc);
	if (ret) {
	dev_err(dev, "failed to add register device with remoteproc core, status = %d\n",
	ret);
	goto release_mem;
	}

	platform_set_drvdata(pdev, ksproc);

	return 0;

	release_mem:
	of_reserved_mem_device_release(dev);
	gpiod_put(ksproc->kick_gpio);
	disable_clk:
	pm_runtime_put_sync(dev);
	disable_rpm:
	pm_runtime_disable(dev);
	return ret;
	}

	static void keystone_rproc_remove(struct platform_device *pdev)
	{
	struct keystone_rproc *ksproc = platform_get_drvdata(pdev);

	rproc_del(ksproc->rproc);
	gpiod_put(ksproc->kick_gpio);
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	of_reserved_mem_device_release(&pdev->dev);
	}

	static const struct of_device_id keystone_rproc_of_match[] = {
	{ .compatible = "ti,k2hk-dsp", },
	{ .compatible = "ti,k2l-dsp", },
	{ .compatible = "ti,k2e-dsp", },
	{ .compatible = "ti,k2g-dsp", },
	{ /* sentinel */ },
	};
	MODULE_DEVICE_TABLE(of, keystone_rproc_of_match);

	static struct platform_driver keystone_rproc_driver = {
	.probe = keystone_rproc_probe,
	.remove_new = keystone_rproc_remove,
	.driver = {
	.name = "keystone-rproc",
	.of_match_table = keystone_rproc_of_match,
	},
	};

	module_platform_driver(keystone_rproc_driver);

	MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("TI Keystone DSP Remoteproc driver");