text: /*
   * Adding PCI-E MSI support for PPC4XX SoCs.
   *
   * Copyright (c) 2010, Applied Micro Circuits Corporation
   * Authors:	Tirumala R Marri <tmarri@apm.com>
   *		Feng Kan <fkan@apm.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as
   * published by the Free Software Foundation; either version 2 of
   * the License, or (at your option) any later version.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  #include <linux/irq.h>
  #include <linux/pci.h>
  #include <linux/msi.h>
  #include <linux/of_platform.h>
  #include <linux/interrupt.h>
  #include <linux/export.h>
  #include <linux/kernel.h>
  #include <asm/prom.h>
  #include <asm/hw_irq.h>
  #include <asm/ppc-pci.h>
  #include <asm/dcr.h>
  #include <asm/dcr-regs.h>
  #include <asm/msi_bitmap.h>
  
  #define PEIH_TERMADH	0x00
  #define PEIH_TERMADL	0x08
  #define PEIH_MSIED	0x10
  #define PEIH_MSIMK	0x18
  #define PEIH_MSIASS	0x20
  #define PEIH_FLUSH0	0x30
  #define PEIH_FLUSH1	0x38
  #define PEIH_CNTRST	0x48
  
  static int msi_irqs;
  
  struct ppc4xx_msi {
  	u32 msi_addr_lo;
  	u32 msi_addr_hi;
  	void __iomem *msi_regs;
  	int *msi_virqs;
  	struct msi_bitmap bitmap;
  	struct device_node *msi_dev;
  };
  
  static struct ppc4xx_msi ppc4xx_msi;
  
  static int ppc4xx_msi_init_allocator(struct platform_device *dev,
  		struct ppc4xx_msi *msi_data)
  {
  	int err;
  
  	err = msi_bitmap_alloc(&msi_data->bitmap, msi_irqs,
  			      dev->dev.of_node);
  	if (err)
  		return err;
  
  	err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  	if (err < 0) {
  		msi_bitmap_free(&msi_data->bitmap);
  		return err;
  	}
  
  	return 0;
  }
  
  static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  {
  	int int_no = -ENOMEM;
  	unsigned int virq;
  	struct msi_msg msg;
  	struct msi_desc *entry;
  	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  
  	dev_dbg(&dev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
  		__func__, nvec, type);
  	if (type == PCI_CAP_ID_MSIX)
  		pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
  
  	msi_data->msi_virqs = kmalloc((msi_irqs) * sizeof(int), GFP_KERNEL);
  	if (!msi_data->msi_virqs)
  		return -ENOMEM;
  
  	list_for_each_entry(entry, &dev->msi_list, list) {
  		int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
  		if (int_no >= 0)
  			break;
  		if (int_no < 0) {
  			pr_debug("%s: fail allocating msi interrupt\n",
  					__func__);
  		}
  		virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
  		if (virq == NO_IRQ) {
  			dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
  			msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
  			return -ENOSPC;
  		}
  		dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
  
  		/* Setup msi address space */
  		msg.address_hi = msi_data->msi_addr_hi;
  		msg.address_lo = msi_data->msi_addr_lo;
  
  		irq_set_msi_desc(virq, entry);
  		msg.data = int_no;
  		pci_write_msi_msg(virq, &msg);
  	}
  	return 0;
  }
  
  void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
  {
  	struct msi_desc *entry;
  	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
  	irq_hw_number_t hwirq;
  
  	dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
  
  	list_for_each_entry(entry, &dev->msi_list, list) {
  		if (entry->irq == NO_IRQ)
  			continue;
  		hwirq = virq_to_hw(entry->irq);
  		irq_set_msi_desc(entry->irq, NULL);
  		irq_dispose_mapping(entry->irq);
  		msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
  	}
  }
  
  static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
  				 struct resource res, struct ppc4xx_msi *msi)
  {
  	const u32 *msi_data;
  	const u32 *msi_mask;
  	const u32 *sdr_addr;
  	dma_addr_t msi_phys;
  	void *msi_virt;
  
  	sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
  	if (!sdr_addr)
  		return -1;
  
  	mtdcri(SDR0, *sdr_addr, upper_32_bits(res.start));	/*HIGH addr */
  	mtdcri(SDR0, *sdr_addr + 1, lower_32_bits(res.start));	/* Low addr */
  
  	msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
  	if (!msi->msi_dev)
  		return -ENODEV;
  
  	msi->msi_regs = of_iomap(msi->msi_dev, 0);
  	if (!msi->msi_regs) {
  		dev_err(&dev->dev, "of_iomap problem failed\n");
  		return -ENOMEM;
  	}
  	dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
  		(u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
  
  	msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
  	if (!msi_virt)
  		return -ENOMEM;
  	msi->msi_addr_hi = upper_32_bits(msi_phys);
  	msi->msi_addr_lo = lower_32_bits(msi_phys & 0xffffffff);
  	dev_dbg(&dev->dev, "PCIE-MSI: msi address high 0x%x, low 0x%x\n",
  		msi->msi_addr_hi, msi->msi_addr_lo);
  
  	/* Progam the Interrupt handler Termination addr registers */
  	out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
  	out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
  
  	msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
  	if (!msi_data)
  		return -1;
  	msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
  	if (!msi_mask)
  		return -1;
  	/* Program MSI Expected data and Mask bits */
  	out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
  	out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
  
  	dma_free_coherent(&dev->dev, 64, msi_virt, msi_phys);
  
  	return 0;
  }
  
  static int ppc4xx_of_msi_remove(struct platform_device *dev)
  {
  	struct ppc4xx_msi *msi = dev->dev.platform_data;
  	int i;
  	int virq;
  
  	for (i = 0; i < msi_irqs; i++) {
  		virq = msi->msi_virqs[i];
  		if (virq != NO_IRQ)
  			irq_dispose_mapping(virq);
  	}
  
  	if (msi->bitmap.bitmap)
  		msi_bitmap_free(&msi->bitmap);
  	iounmap(msi->msi_regs);
  	of_node_put(msi->msi_dev);
  	kfree(msi);
  
  	return 0;
  }
  
  static int ppc4xx_msi_probe(struct platform_device *dev)
  {
  	struct ppc4xx_msi *msi;
  	struct resource res;
  	int err = 0;
  	struct pci_controller *phb;
  
  	dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
  
  	msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
  	if (!msi) {
  		dev_err(&dev->dev, "No memory for MSI structure\n");
  		return -ENOMEM;
  	}
  	dev->dev.platform_data = msi;
  
  	/* Get MSI ranges */
  	err = of_address_to_resource(dev->dev.of_node, 0, &res);
  	if (err) {
  		dev_err(&dev->dev, "%s resource error!\n",
  			dev->dev.of_node->full_name);
  		goto error_out;
  	}
  
  	msi_irqs = of_irq_count(dev->dev.of_node);
  	if (!msi_irqs)
  		return -ENODEV;
  
  	if (ppc4xx_setup_pcieh_hw(dev, res, msi))
  		goto error_out;
  
  	err = ppc4xx_msi_init_allocator(dev, msi);
  	if (err) {
  		dev_err(&dev->dev, "Error allocating MSI bitmap\n");
  		goto error_out;
  	}
  	ppc4xx_msi = *msi;
  
  	list_for_each_entry(phb, &hose_list, list_node) {
  		phb->controller_ops.setup_msi_irqs = ppc4xx_setup_msi_irqs;
  		phb->controller_ops.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
  	}
  	return err;
  
  error_out:
  	ppc4xx_of_msi_remove(dev);
  	return err;
  }
  static const struct of_device_id ppc4xx_msi_ids[] = {
  	{
  		.compatible = "amcc,ppc4xx-msi",
  	},
  	{}
  };
  static struct platform_driver ppc4xx_msi_driver = {
  	.probe = ppc4xx_msi_probe,
  	.remove = ppc4xx_of_msi_remove,
  	.driver = {
  		   .name = "ppc4xx-msi",
  		   .of_match_table = ppc4xx_msi_ids,
  		   },
  
  };
  
  static __init int ppc4xx_msi_init(void)
  {
  	return platform_driver_register(&ppc4xx_msi_driver);
  }
  
  subsys_initcall(ppc4xx_msi_init);
  