/alps/pcitool

/**

 *

 * @file int.c

 * @author Guillermo Marcus

 * @date 2009-04-05

 * @brief Contains the interrupt handler.

 *

 */

#include <linux/version.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/list.h>

#include <linux/interrupt.h>

#include <linux/pci.h>

#include <linux/cdev.h>

#include <linux/wait.h>

#include <linux/sched.h>

#include <stdbool.h>

#include "base.h"

/**

 *

 * Acknowledges the receival of an interrupt to the card.

 *

 * @returns true if the card was acknowledget

 * @returns false if the interrupt was not for one of our cards

 *

 * @see check_acknowlegde_channel

 *

 */

static bool pcidriver_irq_acknowledge(pcidriver_privdata_t *privdata)

{

    int channel = 0;

    atomic_inc(&(privdata->irq_outstanding[channel]));

    wake_up_interruptible(&(privdata->irq_queues[channel]));

    return true;

}

/**

 *

 * Handles IRQs. At the moment, this acknowledges the card that this IRQ

 * was received and then increases the driver's IRQ counter.

 *

 * @see pcidriver_irq_acknowledge

 *

 */

static irqreturn_t pcidriver_irq_handler(int irq, void *dev_id)

{

    pcidriver_privdata_t *privdata = (pcidriver_privdata_t *)dev_id;

    if (!pcidriver_irq_acknowledge(privdata))

        return IRQ_NONE;

    privdata->irq_count++;

    return IRQ_HANDLED;

}

/**

 *

 * If IRQ-handling is enabled, this function will be called from pcidriver_probe

 * to initialize the IRQ handling (maps the BARs)

 *

 */

int pcidriver_probe_irq(pcidriver_privdata_t *privdata)

{

    unsigned char int_pin, int_line;

    unsigned long bar_addr, bar_len, bar_flags;

    int i;

    int err;

    for (i = 0; i < 6; i++)

        privdata->bars_kmapped[i] = NULL;

    for (i = 0; i < 6; i++) {

        bar_addr = pci_resource_start(privdata->pdev, i);

        bar_len = pci_resource_len(privdata->pdev, i);

        bar_flags = pci_resource_flags(privdata->pdev, i);

        /* check if it is a valid BAR, skip if not */

        if ((bar_addr == 0) || (bar_len == 0))

            continue;

        /* Skip IO regions (map only mem regions) */

        if (bar_flags & IORESOURCE_IO)

            continue;

        /* Check if the region is available */

        if ((err = pci_request_region(privdata->pdev, i, NULL)) != 0) {

            mod_info( "Failed to request BAR memory region.\n" );

            return err;

        }

        /* Map it into kernel space. */

        /* For x86 this is just a dereference of the pointer, but that is

         * not portable. So we need to do the portable way. Thanks Joern!

         */

        /* respect the cacheable-bility of the region */

        if (bar_flags & IORESOURCE_PREFETCH)

            privdata->bars_kmapped[i] = ioremap(bar_addr, bar_len);

        else

            privdata->bars_kmapped[i] = ioremap_nocache(bar_addr, bar_len);

        /* check for error */

        if (privdata->bars_kmapped[i] == NULL) {

            mod_info( "Failed to remap BAR%d into kernel space.\n", i );

            return -EIO;

        }

    }

    /* Initialize the interrupt handler for this device */

    /* Initialize the wait queues */

    for (i = 0; i < PCIDRIVER_INT_MAXSOURCES; i++) {

        init_waitqueue_head(&(privdata->irq_queues[i]));

        atomic_set(&(privdata->irq_outstanding[i]), 0);

    }

    /* Initialize the irq config */

    if ((err = pci_read_config_byte(privdata->pdev, PCI_INTERRUPT_PIN, &int_pin)) != 0) {

        /* continue without interrupts */

        int_pin = 0;

        mod_info("Error getting the interrupt pin. Disabling interrupts for this device\n");

    }

    /* Disable interrupts and activate them if everything can be set up properly */

    privdata->irq_enabled = 0;

    if (int_pin == 0)

        return 0;

    if ((err = pci_read_config_byte(privdata->pdev, PCI_INTERRUPT_LINE, &int_line)) != 0) {

        mod_info("Error getting the interrupt line. Disabling interrupts for this device\n");

        return 0;

    }

    /* Enable interrupts using MSI mode */

    if (!pci_enable_msi(privdata->pdev))

        privdata->msi_mode = 1;

    /* register interrupt handler */

    if ((err = request_irq(privdata->pdev->irq, pcidriver_irq_handler, IRQF_SHARED, MODNAME, privdata)) != 0) {

        mod_info("Error registering the interrupt handler. Disabling interrupts for this device\n");

        return 0;

    }

    privdata->irq_enabled = 1;

    mod_info("Registered Interrupt Handler at pin %i, line %i, IRQ %i\n", int_pin, int_line, privdata->pdev->irq );

    return 0;

}

/**

 *

 * Frees/cleans up the data structures, called from pcidriver_remove()

 *

 */

void pcidriver_remove_irq(pcidriver_privdata_t *privdata)

{

    /* Release the IRQ handler */

    if (privdata->irq_enabled != 0)

        free_irq(privdata->pdev->irq, privdata);

    if (privdata->msi_mode) {

        pci_disable_msi(privdata->pdev);

        privdata->msi_mode = 0;

    }

    pcidriver_irq_unmap_bars(privdata);

}

/**

 *

 * Unmaps the BARs and releases them

 *

 */

void pcidriver_irq_unmap_bars(pcidriver_privdata_t *privdata)

{

    int i;

    for (i = 0; i < 6; i++) {

        if (privdata->bars_kmapped[i] == NULL)

            continue;

        iounmap((void*)privdata->bars_kmapped[i]);

        pci_release_region(privdata->pdev, i);

    }

}