--- /dev/null
+/*
+ * 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");
+
projects / linux-beck.git / commitdiff