Subversion Repositories test_project

/*

 *  ricoh_mmc.c - Dummy driver to disable the Rioch MMC controller.

 *

 *  Copyright (C) 2007 Philip Langdale, All Rights Reserved.

 *

 * 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 is a conceptually ridiculous driver, but it is required by the way

 * the Ricoh multi-function R5C832 works. This chip implements firewire

 * and four different memory card controllers. Two of those controllers are

 * an SDHCI controller and a proprietary MMC controller. The linux SDHCI

 * driver supports MMC cards but the chip detects MMC cards in hardware

 * and directs them to the MMC controller - so the SDHCI driver never sees

 * them. To get around this, we must disable the useless MMC controller.

 * At that point, the SDHCI controller will start seeing them. As a bonus,

 * a detection event occurs immediately, even if the MMC card is already

 * in the reader.

 *

 * The relevant registers live on the firewire function, so this is unavoidably

 * ugly. Such is life.

 */

#include <linux/pci.h>

#define DRIVER_NAME "ricoh-mmc"

static const struct pci_device_id pci_ids[] __devinitdata = {

        {

                .vendor         = PCI_VENDOR_ID_RICOH,

                .device         = PCI_DEVICE_ID_RICOH_R5C843,

                .subvendor      = PCI_ANY_ID,

                .subdevice      = PCI_ANY_ID,

        },

        { /* end: all zeroes */ },

};

MODULE_DEVICE_TABLE(pci, pci_ids);

static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,

                                     const struct pci_device_id *ent)

{

        u8 rev;

        struct pci_dev *fw_dev = NULL;

        BUG_ON(pdev == NULL);

        BUG_ON(ent == NULL);

        pci_read_config_byte(pdev, PCI_CLASS_REVISION, &rev);

        printk(KERN_INFO DRIVER_NAME

                ": Ricoh MMC controller found at %s [%04x:%04x] (rev %x)\n",

                pci_name(pdev), (int)pdev->vendor, (int)pdev->device,

                (int)rev);

        while ((fw_dev = pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, fw_dev))) {

                if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&

                    pdev->bus == fw_dev->bus) {

                        u8 write_enable;

                        u8 disable;

                        pci_read_config_byte(fw_dev, 0xCB, &disable);

                        if (disable & 0x02) {

                                printk(KERN_INFO DRIVER_NAME

                                       ": Controller already disabled. Nothing to do.\n");

                                return -ENODEV;

                        }

                        pci_read_config_byte(fw_dev, 0xCA, &write_enable);

                        pci_write_config_byte(fw_dev, 0xCA, 0x57);

                        pci_write_config_byte(fw_dev, 0xCB, disable | 0x02);

                        pci_write_config_byte(fw_dev, 0xCA, write_enable);

                        pci_set_drvdata(pdev, fw_dev);

                        printk(KERN_INFO DRIVER_NAME

                               ": Controller is now disabled.\n");

                        break;

                }

        }

        if (pci_get_drvdata(pdev) == NULL) {

                printk(KERN_WARNING DRIVER_NAME

                       ": Main firewire function not found. Cannot disable controller.\n");

                return -ENODEV;

        }

        return 0;

}

static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)

{

        u8 write_enable;

        u8 disable;

        struct pci_dev *fw_dev = NULL;

        fw_dev = pci_get_drvdata(pdev);

        BUG_ON(fw_dev == NULL);

        pci_read_config_byte(fw_dev, 0xCA, &write_enable);

        pci_read_config_byte(fw_dev, 0xCB, &disable);

        pci_write_config_byte(fw_dev, 0xCA, 0x57);

        pci_write_config_byte(fw_dev, 0xCB, disable & ~0x02);

        pci_write_config_byte(fw_dev, 0xCA, write_enable);

        printk(KERN_INFO DRIVER_NAME

               ": Controller is now re-enabled.\n");

        pci_set_drvdata(pdev, NULL);

}

static struct pci_driver ricoh_mmc_driver = {

        .name =         DRIVER_NAME,

        .id_table =     pci_ids,

        .probe =        ricoh_mmc_probe,

        .remove =       __devexit_p(ricoh_mmc_remove),

};

/*****************************************************************************\

 *                                                                           *

 * Driver init/exit                                                          *

 *                                                                           *

\*****************************************************************************/

static int __init ricoh_mmc_drv_init(void)

{

        printk(KERN_INFO DRIVER_NAME

                ": Ricoh MMC Controller disabling driver\n");

        printk(KERN_INFO DRIVER_NAME ": Copyright(c) Philip Langdale\n");

        return pci_register_driver(&ricoh_mmc_driver);

}

static void __exit ricoh_mmc_drv_exit(void)

{

        pci_unregister_driver(&ricoh_mmc_driver);

}

module_init(ricoh_mmc_drv_init);

module_exit(ricoh_mmc_drv_exit);

MODULE_AUTHOR("Philip Langdale <philipl@alumni.utexas.net>");

MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");

MODULE_LICENSE("GPL");