Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / drivers / mmc / host / ricoh_mmc.c
1 /*
2  *  ricoh_mmc.c - Dummy driver to disable the Rioch MMC controller.
3  *
4  *  Copyright (C) 2007 Philip Langdale, All Rights Reserved.
5  *
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.
10  */
11
12 /*
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
22  * in the reader.
23  *
24  * The relevant registers live on the firewire function, so this is unavoidably
25  * ugly. Such is life.
26  */
27
28 #include <linux/pci.h>
29
30 #define DRIVER_NAME "ricoh-mmc"
31
32 static const struct pci_device_id pci_ids[] __devinitdata = {
33         {
34                 .vendor         = PCI_VENDOR_ID_RICOH,
35                 .device         = PCI_DEVICE_ID_RICOH_R5C843,
36                 .subvendor      = PCI_ANY_ID,
37                 .subdevice      = PCI_ANY_ID,
38         },
39         { /* end: all zeroes */ },
40 };
41
42 MODULE_DEVICE_TABLE(pci, pci_ids);
43
44 static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
45                                      const struct pci_device_id *ent)
46 {
47         u8 rev;
48
49         struct pci_dev *fw_dev = NULL;
50
51         BUG_ON(pdev == NULL);
52         BUG_ON(ent == NULL);
53
54         pci_read_config_byte(pdev, PCI_CLASS_REVISION, &rev);
55
56         printk(KERN_INFO DRIVER_NAME
57                 ": Ricoh MMC controller found at %s [%04x:%04x] (rev %x)\n",
58                 pci_name(pdev), (int)pdev->vendor, (int)pdev->device,
59                 (int)rev);
60
61         while ((fw_dev = pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, fw_dev))) {
62                 if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
63                     pdev->bus == fw_dev->bus) {
64                         u8 write_enable;
65                         u8 disable;
66
67                         pci_read_config_byte(fw_dev, 0xCB, &disable);
68                         if (disable & 0x02) {
69                                 printk(KERN_INFO DRIVER_NAME
70                                        ": Controller already disabled. Nothing to do.\n");
71                                 return -ENODEV;
72                         }
73
74                         pci_read_config_byte(fw_dev, 0xCA, &write_enable);
75                         pci_write_config_byte(fw_dev, 0xCA, 0x57);
76                         pci_write_config_byte(fw_dev, 0xCB, disable | 0x02);
77                         pci_write_config_byte(fw_dev, 0xCA, write_enable);
78
79                         pci_set_drvdata(pdev, fw_dev);
80
81                         printk(KERN_INFO DRIVER_NAME
82                                ": Controller is now disabled.\n");
83
84                         break;
85                 }
86         }
87
88         if (pci_get_drvdata(pdev) == NULL) {
89                 printk(KERN_WARNING DRIVER_NAME
90                        ": Main firewire function not found. Cannot disable controller.\n");
91                 return -ENODEV;
92         }
93
94         return 0;
95 }
96
97 static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)
98 {
99         u8 write_enable;
100         u8 disable;
101         struct pci_dev *fw_dev = NULL;
102
103         fw_dev = pci_get_drvdata(pdev);
104         BUG_ON(fw_dev == NULL);
105
106         pci_read_config_byte(fw_dev, 0xCA, &write_enable);
107         pci_read_config_byte(fw_dev, 0xCB, &disable);
108         pci_write_config_byte(fw_dev, 0xCA, 0x57);
109         pci_write_config_byte(fw_dev, 0xCB, disable & ~0x02);
110         pci_write_config_byte(fw_dev, 0xCA, write_enable);
111
112         printk(KERN_INFO DRIVER_NAME
113                ": Controller is now re-enabled.\n");
114
115         pci_set_drvdata(pdev, NULL);
116 }
117
118 static struct pci_driver ricoh_mmc_driver = {
119         .name =         DRIVER_NAME,
120         .id_table =     pci_ids,
121         .probe =        ricoh_mmc_probe,
122         .remove =       __devexit_p(ricoh_mmc_remove),
123 };
124
125 /*****************************************************************************\
126  *                                                                           *
127  * Driver init/exit                                                          *
128  *                                                                           *
129 \*****************************************************************************/
130
131 static int __init ricoh_mmc_drv_init(void)
132 {
133         printk(KERN_INFO DRIVER_NAME
134                 ": Ricoh MMC Controller disabling driver\n");
135         printk(KERN_INFO DRIVER_NAME ": Copyright(c) Philip Langdale\n");
136
137         return pci_register_driver(&ricoh_mmc_driver);
138 }
139
140 static void __exit ricoh_mmc_drv_exit(void)
141 {
142         pci_unregister_driver(&ricoh_mmc_driver);
143 }
144
145 module_init(ricoh_mmc_drv_init);
146 module_exit(ricoh_mmc_drv_exit);
147
148 MODULE_AUTHOR("Philip Langdale <philipl@alumni.utexas.net>");
149 MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
150 MODULE_LICENSE("GPL");
151