text: /*
   * AMD Cryptographic Coprocessor (CCP) driver
   *
   * Copyright (C) 2014 Advanced Micro Devices, Inc.
   *
   * Author: Tom Lendacky <thomas.lendacky@amd.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.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/device.h>
  #include <linux/platform_device.h>
  #include <linux/ioport.h>
  #include <linux/dma-mapping.h>
  #include <linux/kthread.h>
  #include <linux/sched.h>
  #include <linux/interrupt.h>
  #include <linux/spinlock.h>
  #include <linux/delay.h>
  #include <linux/ccp.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  #include <linux/acpi.h>
  
  #include "ccp-dev.h"
  
  struct ccp_platform {
  	int coherent;
  };
  
  static int ccp_get_irq(struct ccp_device *ccp)
  {
  	struct device *dev = ccp->dev;
  	struct platform_device *pdev = to_platform_device(dev);
  	int ret;
  
  	ret = platform_get_irq(pdev, 0);
  	if (ret < 0)
  		return ret;
  
  	ccp->irq = ret;
  	ret = request_irq(ccp->irq, ccp_irq_handler, 0, "ccp", dev);
  	if (ret) {
  		dev_notice(dev, "unable to allocate IRQ (%d)\n", ret);
  		return ret;
  	}
  
  	return 0;
  }
  
  static int ccp_get_irqs(struct ccp_device *ccp)
  {
  	struct device *dev = ccp->dev;
  	int ret;
  
  	ret = ccp_get_irq(ccp);
  	if (!ret)
  		return 0;
  
  	/* Couldn't get an interrupt */
  	dev_notice(dev, "could not enable interrupts (%d)\n", ret);
  
  	return ret;
  }
  
  static void ccp_free_irqs(struct ccp_device *ccp)
  {
  	struct device *dev = ccp->dev;
  
  	free_irq(ccp->irq, dev);
  }
  
  static struct resource *ccp_find_mmio_area(struct ccp_device *ccp)
  {
  	struct device *dev = ccp->dev;
  	struct platform_device *pdev = to_platform_device(dev);
  	struct resource *ior;
  
  	ior = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (ior && (resource_size(ior) >= 0x800))
  		return ior;
  
  	return NULL;
  }
  
  static int ccp_platform_probe(struct platform_device *pdev)
  {
  	struct ccp_device *ccp;
  	struct ccp_platform *ccp_platform;
  	struct device *dev = &pdev->dev;
  	enum dev_dma_attr attr;
  	struct resource *ior;
  	int ret;
  
  	ret = -ENOMEM;
  	ccp = ccp_alloc_struct(dev);
  	if (!ccp)
  		goto e_err;
  
  	ccp_platform = devm_kzalloc(dev, sizeof(*ccp_platform), GFP_KERNEL);
  	if (!ccp_platform)
  		goto e_err;
  
  	ccp->dev_specific = ccp_platform;
  	ccp->get_irq = ccp_get_irqs;
  	ccp->free_irq = ccp_free_irqs;
  
  	ior = ccp_find_mmio_area(ccp);
  	ccp->io_map = devm_ioremap_resource(dev, ior);
  	if (IS_ERR(ccp->io_map)) {
  		ret = PTR_ERR(ccp->io_map);
  		goto e_err;
  	}
  	ccp->io_regs = ccp->io_map;
  
  	attr = device_get_dma_attr(dev);
  	if (attr == DEV_DMA_NOT_SUPPORTED) {
  		dev_err(dev, "DMA is not supported");
  		goto e_err;
  	}
  
  	ccp_platform->coherent = (attr == DEV_DMA_COHERENT);
  	if (ccp_platform->coherent)
  		ccp->axcache = CACHE_WB_NO_ALLOC;
  	else
  		ccp->axcache = CACHE_NONE;
  
  	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48));
  	if (ret) {
  		dev_err(dev, "dma_set_mask_and_coherent failed (%d)\n", ret);
  		goto e_err;
  	}
  
  	dev_set_drvdata(dev, ccp);
  
  	ret = ccp_init(ccp);
  	if (ret)
  		goto e_err;
  
  	dev_notice(dev, "enabled\n");
  
  	return 0;
  
  e_err:
  	dev_notice(dev, "initialization failed\n");
  	return ret;
  }
  
  static int ccp_platform_remove(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct ccp_device *ccp = dev_get_drvdata(dev);
  
  	ccp_destroy(ccp);
  
  	dev_notice(dev, "disabled\n");
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int ccp_platform_suspend(struct platform_device *pdev,
  				pm_message_t state)
  {
  	struct device *dev = &pdev->dev;
  	struct ccp_device *ccp = dev_get_drvdata(dev);
  	unsigned long flags;
  	unsigned int i;
  
  	spin_lock_irqsave(&ccp->cmd_lock, flags);
  
  	ccp->suspending = 1;
  
  	/* Wake all the queue kthreads to prepare for suspend */
  	for (i = 0; i < ccp->cmd_q_count; i++)
  		wake_up_process(ccp->cmd_q[i].kthread);
  
  	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
  
  	/* Wait for all queue kthreads to say they're done */
  	while (!ccp_queues_suspended(ccp))
  		wait_event_interruptible(ccp->suspend_queue,
  					 ccp_queues_suspended(ccp));
  
  	return 0;
  }
  
  static int ccp_platform_resume(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct ccp_device *ccp = dev_get_drvdata(dev);
  	unsigned long flags;
  	unsigned int i;
  
  	spin_lock_irqsave(&ccp->cmd_lock, flags);
  
  	ccp->suspending = 0;
  
  	/* Wake up all the kthreads */
  	for (i = 0; i < ccp->cmd_q_count; i++) {
  		ccp->cmd_q[i].suspended = 0;
  		wake_up_process(ccp->cmd_q[i].kthread);
  	}
  
  	spin_unlock_irqrestore(&ccp->cmd_lock, flags);
  
  	return 0;
  }
  #endif
  
  #ifdef CONFIG_ACPI
  static const struct acpi_device_id ccp_acpi_match[] = {
  	{ "AMDI0C00", 0 },
  	{ },
  };
  MODULE_DEVICE_TABLE(acpi, ccp_acpi_match);
  #endif
  
  #ifdef CONFIG_OF
  static const struct of_device_id ccp_of_match[] = {
  	{ .compatible = "amd,ccp-seattle-v1a" },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, ccp_of_match);
  #endif
  
  static struct platform_driver ccp_platform_driver = {
  	.driver = {
  		.name = "ccp",
  #ifdef CONFIG_ACPI
  		.acpi_match_table = ccp_acpi_match,
  #endif
  #ifdef CONFIG_OF
  		.of_match_table = ccp_of_match,
  #endif
  	},
  	.probe = ccp_platform_probe,
  	.remove = ccp_platform_remove,
  #ifdef CONFIG_PM
  	.suspend = ccp_platform_suspend,
  	.resume = ccp_platform_resume,
  #endif
  };
  
  int ccp_platform_init(void)
  {
  	return platform_driver_register(&ccp_platform_driver);
  }
  
  void ccp_platform_exit(void)
  {
  	platform_driver_unregister(&ccp_platform_driver);
  }
  