core.c

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/*
 *  cb710/core.c
 *
 *  Copyright by Michał Mirosław, 2008-2009
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <linux/cb710.h>
#include <linux/gfp.h>

static DEFINE_IDA(cb710_ida);
static DEFINE_SPINLOCK(cb710_ida_lock);

void cb710_pci_update_config_reg(struct pci_dev *pdev,
    int reg, uint32_t mask, uint32_t xor)
{
    u32 rval;

    pci_read_config_dword(pdev, reg, &rval);
    rval = (rval & mask) ^ xor;
    pci_write_config_dword(pdev, reg, rval);
}
EXPORT_SYMBOL_GPL(cb710_pci_update_config_reg);

/* Some magic writes based on Windows driver init code */
static int __devinit cb710_pci_configure(struct pci_dev *pdev)
{
    unsigned int devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
    struct pci_dev *pdev0;
    u32 val;

    cb710_pci_update_config_reg(pdev, 0x48,
        ~0x000000FF, 0x0000003F);

    pci_read_config_dword(pdev, 0x48, &val);
    if (val & 0x80000000)
        return 0;

    pdev0 = pci_get_slot(pdev->bus, devfn);
    if (!pdev0)
        return -ENODEV;

    if (pdev0->vendor == PCI_VENDOR_ID_ENE
        && pdev0->device == PCI_DEVICE_ID_ENE_720) {
        cb710_pci_update_config_reg(pdev0, 0x8C,
            ~0x00F00000, 0x00100000);
        cb710_pci_update_config_reg(pdev0, 0xB0,
            ~0x08000000, 0x08000000);
    }

    cb710_pci_update_config_reg(pdev0, 0x8C,
        ~0x00000F00, 0x00000200);
    cb710_pci_update_config_reg(pdev0, 0x90,
        ~0x00060000, 0x00040000);

    pci_dev_put(pdev0);

    return 0;
}

static irqreturn_t cb710_irq_handler(int irq, void *data)
{
    struct cb710_chip *chip = data;
    struct cb710_slot *slot = &chip->slot[0];
    irqreturn_t handled = IRQ_NONE;
    unsigned nr;

    spin_lock(&chip->irq_lock); /* incl. smp_rmb() */

    for (nr = chip->slots; nr; ++slot, --nr) {
        cb710_irq_handler_t handler_func = slot->irq_handler;
        if (handler_func && handler_func(slot))
            handled = IRQ_HANDLED;
    }

    spin_unlock(&chip->irq_lock);

    return handled;
}

static void cb710_release_slot(struct device *dev)
{
#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
    struct cb710_slot *slot = cb710_pdev_to_slot(to_platform_device(dev));
    struct cb710_chip *chip = cb710_slot_to_chip(slot);

    /* slot struct can be freed now */
    atomic_dec(&chip->slot_refs_count);
#endif
}

static int __devinit cb710_register_slot(struct cb710_chip *chip,
    unsigned slot_mask, unsigned io_offset, const char *name)
{
    int nr = chip->slots;
    struct cb710_slot *slot = &chip->slot[nr];
    int err;

    dev_dbg(cb710_chip_dev(chip),
        "register: %s.%d; slot %d; mask %d; IO offset: 0x%02X\n",
        name, chip->platform_id, nr, slot_mask, io_offset);

    /* slot->irq_handler == NULL here; this needs to be
     * seen before platform_device_register() */
    ++chip->slots;
    smp_wmb();

    slot->iobase = chip->iobase + io_offset;
    slot->pdev.name = name;
    slot->pdev.id = chip->platform_id;
    slot->pdev.dev.parent = &chip->pdev->dev;
    slot->pdev.dev.release = cb710_release_slot;

    err = platform_device_register(&slot->pdev);

#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
    atomic_inc(&chip->slot_refs_count);
#endif

    if (err) {
        /* device_initialize() called from platform_device_register()
         * wants this on error path */
        platform_device_put(&slot->pdev);

        /* slot->irq_handler == NULL here anyway, so no lock needed */
        --chip->slots;
        return err;
    }

    chip->slot_mask |= slot_mask;

    return 0;
}

static void cb710_unregister_slot(struct cb710_chip *chip,
    unsigned slot_mask)
{
    int nr = chip->slots - 1;

    if (!(chip->slot_mask & slot_mask))
        return;

    platform_device_unregister(&chip->slot[nr].pdev);

    /* complementary to spin_unlock() in cb710_set_irq_handler() */
    smp_rmb();
    BUG_ON(chip->slot[nr].irq_handler != NULL);

    /* slot->irq_handler == NULL here, so no lock needed */
    --chip->slots;
    chip->slot_mask &= ~slot_mask;
}

void cb710_set_irq_handler(struct cb710_slot *slot,
    cb710_irq_handler_t handler)
{
    struct cb710_chip *chip = cb710_slot_to_chip(slot);
    unsigned long flags;

    spin_lock_irqsave(&chip->irq_lock, flags);
    slot->irq_handler = handler;
    spin_unlock_irqrestore(&chip->irq_lock, flags);
}
EXPORT_SYMBOL_GPL(cb710_set_irq_handler);

#ifdef CONFIG_PM

static int cb710_suspend(struct pci_dev *pdev, pm_message_t state)
{
    struct cb710_chip *chip = pci_get_drvdata(pdev);

    free_irq(pdev->irq, chip);
    pci_save_state(pdev);
    pci_disable_device(pdev);
    if (state.event & PM_EVENT_SLEEP)
        pci_set_power_state(pdev, PCI_D3hot);
    return 0;
}

static int cb710_resume(struct pci_dev *pdev)
{
    struct cb710_chip *chip = pci_get_drvdata(pdev);
    int err;

    pci_set_power_state(pdev, PCI_D0);
    pci_restore_state(pdev);
    err = pcim_enable_device(pdev);
    if (err)
        return err;

    return devm_request_irq(&pdev->dev, pdev->irq,
        cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
}

#endif /* CONFIG_PM */

static int __devinit cb710_probe(struct pci_dev *pdev,
    const struct pci_device_id *ent)
{
    struct cb710_chip *chip;
    unsigned long flags;
    u32 val;
    int err;
    int n = 0;

    err = cb710_pci_configure(pdev);
    if (err)
        return err;

    /* this is actually magic... */
    pci_read_config_dword(pdev, 0x48, &val);
    if (!(val & 0x80000000)) {
        pci_write_config_dword(pdev, 0x48, val|0x71000000);
        pci_read_config_dword(pdev, 0x48, &val);
    }

    dev_dbg(&pdev->dev, "PCI config[0x48] = 0x%08X\n", val);
    if (!(val & 0x70000000))
        return -ENODEV;
    val = (val >> 28) & 7;
    if (val & CB710_SLOT_MMC)
        ++n;
    if (val & CB710_SLOT_MS)
        ++n;
    if (val & CB710_SLOT_SM)
        ++n;

    chip = devm_kzalloc(&pdev->dev,
        sizeof(*chip) + n * sizeof(*chip->slot), GFP_KERNEL);
    if (!chip)
        return -ENOMEM;

    err = pcim_enable_device(pdev);
    if (err)
        return err;

    err = pcim_iomap_regions(pdev, 0x0001, KBUILD_MODNAME);
    if (err)
        return err;

    spin_lock_init(&chip->irq_lock);
    chip->pdev = pdev;
    chip->iobase = pcim_iomap_table(pdev)[0];

    pci_set_drvdata(pdev, chip);

    err = devm_request_irq(&pdev->dev, pdev->irq,
        cb710_irq_handler, IRQF_SHARED, KBUILD_MODNAME, chip);
    if (err)
        return err;

    do {
        if (!ida_pre_get(&cb710_ida, GFP_KERNEL))
            return -ENOMEM;

        spin_lock_irqsave(&cb710_ida_lock, flags);
        err = ida_get_new(&cb710_ida, &chip->platform_id);
        spin_unlock_irqrestore(&cb710_ida_lock, flags);

        if (err && err != -EAGAIN)
            return err;
    } while (err);


    dev_info(&pdev->dev, "id %d, IO 0x%p, IRQ %d\n",
        chip->platform_id, chip->iobase, pdev->irq);

    if (val & CB710_SLOT_MMC) { /* MMC/SD slot */
        err = cb710_register_slot(chip,
            CB710_SLOT_MMC, 0x00, "cb710-mmc");
        if (err)
            return err;
    }

    if (val & CB710_SLOT_MS) {  /* MemoryStick slot */
        err = cb710_register_slot(chip,
            CB710_SLOT_MS, 0x40, "cb710-ms");
        if (err)
            goto unreg_mmc;
    }

    if (val & CB710_SLOT_SM) {  /* SmartMedia slot */
        err = cb710_register_slot(chip,
            CB710_SLOT_SM, 0x60, "cb710-sm");
        if (err)
            goto unreg_ms;
    }

    return 0;
unreg_ms:
    cb710_unregister_slot(chip, CB710_SLOT_MS);
unreg_mmc:
    cb710_unregister_slot(chip, CB710_SLOT_MMC);

#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
    BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
#endif
    return err;
}

static void __devexit cb710_remove_one(struct pci_dev *pdev)
{
    struct cb710_chip *chip = pci_get_drvdata(pdev);
    unsigned long flags;

    cb710_unregister_slot(chip, CB710_SLOT_SM);
    cb710_unregister_slot(chip, CB710_SLOT_MS);
    cb710_unregister_slot(chip, CB710_SLOT_MMC);
#ifdef CONFIG_CB710_DEBUG_ASSUMPTIONS
    BUG_ON(atomic_read(&chip->slot_refs_count) != 0);
#endif

    spin_lock_irqsave(&cb710_ida_lock, flags);
    ida_remove(&cb710_ida, chip->platform_id);
    spin_unlock_irqrestore(&cb710_ida_lock, flags);
}

static const struct pci_device_id cb710_pci_tbl[] = {
    { PCI_VENDOR_ID_ENE, PCI_DEVICE_ID_ENE_CB710_FLASH,
        PCI_ANY_ID, PCI_ANY_ID, },
    { 0, }
};

static struct pci_driver cb710_driver = {
    .name = KBUILD_MODNAME,
    .id_table = cb710_pci_tbl,
    .probe = cb710_probe,
    .remove = __devexit_p(cb710_remove_one),
#ifdef CONFIG_PM
    .suspend = cb710_suspend,
    .resume = cb710_resume,
#endif
};

static int __init cb710_init_module(void)
{
    return pci_register_driver(&cb710_driver);
}

static void __exit cb710_cleanup_module(void)
{
    pci_unregister_driver(&cb710_driver);
    ida_destroy(&cb710_ida);
}

module_init(cb710_init_module);
module_exit(cb710_cleanup_module);

MODULE_AUTHOR("Michał Mirosław <[email protected]>");
MODULE_DESCRIPTION("ENE CB710 memory card reader driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cb710_pci_tbl);