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-rw-r--r--drivers/mmc/host/ricoh_mmc.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/mmc/host/ricoh_mmc.c b/drivers/mmc/host/ricoh_mmc.c
new file mode 100644
index 000000000000..1e8704533bc5
--- /dev/null
+++ b/drivers/mmc/host/ricoh_mmc.c
@@ -0,0 +1,151 @@
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
32static 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
42MODULE_DEVICE_TABLE(pci, pci_ids);
43
44static 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
97static 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
118static 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
131static 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
140static void __exit ricoh_mmc_drv_exit(void)
141{
142 pci_unregister_driver(&ricoh_mmc_driver);
143}
144
145module_init(ricoh_mmc_drv_init);
146module_exit(ricoh_mmc_drv_exit);
147
148MODULE_AUTHOR("Philip Langdale <philipl@alumni.utexas.net>");
149MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
150MODULE_LICENSE("GPL");
151