ppc4xx_msi.c

Go to the documentation of this file.

/*
 * Adding PCI-E MSI support for PPC4XX SoCs.
 *
 * Copyright (c) 2010, Applied Micro Circuits Corporation
 * Authors: Tirumala R Marri <[email protected]>
 *      Feng Kan <[email protected]>
 *
 * 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/bootmem.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;

    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;
        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;

    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;
        irq_set_msi_desc(entry->irq, NULL);
        msi_bitmap_free_hwirqs(&msi_data->bitmap,
                virq_to_hw(entry->irq), 1);
        irq_dispose_mapping(entry->irq);
    }
}

static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
{
    dev_dbg(&pdev->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");

    return 0;
}

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 __devinit ppc4xx_msi_probe(struct platform_device *dev)
{
    struct ppc4xx_msi *msi;
    struct resource res;
    int err = 0;

    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;

    ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
    ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
    ppc_md.msi_check_device = ppc4xx_msi_check_device;
    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",
           .owner = THIS_MODULE,
           .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);