2 * ricoh_mmc.c - Dummy driver to disable the Rioch MMC controller.
4 * Copyright (C) 2007 Philip Langdale, All Rights Reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
13 * This is a conceptually ridiculous driver, but it is required by the way
14 * the Ricoh multi-function R5C832 works. This chip implements firewire
15 * and four different memory card controllers. Two of those controllers are
16 * an SDHCI controller and a proprietary MMC controller. The linux SDHCI
17 * driver supports MMC cards but the chip detects MMC cards in hardware
18 * and directs them to the MMC controller - so the SDHCI driver never sees
19 * them. To get around this, we must disable the useless MMC controller.
20 * At that point, the SDHCI controller will start seeing them. As a bonus,
21 * a detection event occurs immediately, even if the MMC card is already
24 * The relevant registers live on the firewire function, so this is unavoidably
28 #include <linux/pci.h>
30 #define DRIVER_NAME "ricoh-mmc"
32 static const struct pci_device_id pci_ids[] __devinitdata = {
34 .vendor = PCI_VENDOR_ID_RICOH,
35 .device = PCI_DEVICE_ID_RICOH_R5C843,
36 .subvendor = PCI_ANY_ID,
37 .subdevice = PCI_ANY_ID,
39 { /* end: all zeroes */ },
42 MODULE_DEVICE_TABLE(pci, pci_ids);
44 static int ricoh_mmc_disable(struct pci_dev *fw_dev)
49 pci_read_config_byte(fw_dev, 0xCB, &disable);
51 printk(KERN_INFO DRIVER_NAME
52 ": Controller already disabled. Nothing to do.\n");
56 pci_read_config_byte(fw_dev, 0xCA, &write_enable);
57 pci_write_config_byte(fw_dev, 0xCA, 0x57);
58 pci_write_config_byte(fw_dev, 0xCB, disable | 0x02);
59 pci_write_config_byte(fw_dev, 0xCA, write_enable);
61 printk(KERN_INFO DRIVER_NAME
62 ": Controller is now disabled.\n");
67 static int ricoh_mmc_enable(struct pci_dev *fw_dev)
72 pci_read_config_byte(fw_dev, 0xCA, &write_enable);
73 pci_read_config_byte(fw_dev, 0xCB, &disable);
74 pci_write_config_byte(fw_dev, 0xCA, 0x57);
75 pci_write_config_byte(fw_dev, 0xCB, disable & ~0x02);
76 pci_write_config_byte(fw_dev, 0xCA, write_enable);
78 printk(KERN_INFO DRIVER_NAME
79 ": Controller is now re-enabled.\n");
84 static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
85 const struct pci_device_id *ent)
89 struct pci_dev *fw_dev = NULL;
94 pci_read_config_byte(pdev, PCI_CLASS_REVISION, &rev);
96 printk(KERN_INFO DRIVER_NAME
97 ": Ricoh MMC controller found at %s [%04x:%04x] (rev %x)\n",
98 pci_name(pdev), (int)pdev->vendor, (int)pdev->device,
101 while ((fw_dev = pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, fw_dev))) {
102 if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
103 pdev->bus == fw_dev->bus) {
104 if (ricoh_mmc_disable(fw_dev) != 0) {
108 pci_set_drvdata(pdev, fw_dev);
114 if (pci_get_drvdata(pdev) == NULL) {
115 printk(KERN_WARNING DRIVER_NAME
116 ": Main firewire function not found. Cannot disable controller.\n");
123 static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)
125 struct pci_dev *fw_dev = NULL;
127 fw_dev = pci_get_drvdata(pdev);
128 BUG_ON(fw_dev == NULL);
130 ricoh_mmc_enable(fw_dev);
132 pci_set_drvdata(pdev, NULL);
135 static int ricoh_mmc_suspend (struct pci_dev *pdev, pm_message_t state)
137 struct pci_dev *fw_dev = NULL;
139 fw_dev = pci_get_drvdata(pdev);
140 BUG_ON(fw_dev == NULL);
142 printk(KERN_INFO DRIVER_NAME ": Suspending.\n");
144 ricoh_mmc_enable(fw_dev);
149 static int ricoh_mmc_resume (struct pci_dev *pdev)
151 struct pci_dev *fw_dev = NULL;
153 fw_dev = pci_get_drvdata(pdev);
154 BUG_ON(fw_dev == NULL);
156 printk(KERN_INFO DRIVER_NAME ": Resuming.\n");
158 ricoh_mmc_disable(fw_dev);
163 static struct pci_driver ricoh_mmc_driver = {
166 .probe = ricoh_mmc_probe,
167 .remove = __devexit_p(ricoh_mmc_remove),
168 .suspend = ricoh_mmc_suspend,
169 .resume = ricoh_mmc_resume,
172 /*****************************************************************************\
176 \*****************************************************************************/
178 static int __init ricoh_mmc_drv_init(void)
180 printk(KERN_INFO DRIVER_NAME
181 ": Ricoh MMC Controller disabling driver\n");
182 printk(KERN_INFO DRIVER_NAME ": Copyright(c) Philip Langdale\n");
184 return pci_register_driver(&ricoh_mmc_driver);
187 static void __exit ricoh_mmc_drv_exit(void)
189 pci_unregister_driver(&ricoh_mmc_driver);
192 module_init(ricoh_mmc_drv_init);
193 module_exit(ricoh_mmc_drv_exit);
195 MODULE_AUTHOR("Philip Langdale <philipl@alumni.utexas.net>");
196 MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
197 MODULE_LICENSE("GPL");