summaryrefslogtreecommitdiffstats
path: root/drivers/mmc/host/ricoh_mmc.c
blob: a16d7609e4eede4fa88f4ecc6b3ac9dce699038a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 *  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 ricoh_mmc_disable(struct pci_dev *fw_dev)
{
	u8 write_enable;
	u8 write_target;
	u8 disable;

	if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
		/* via RL5C476 */

		pci_read_config_byte(fw_dev, 0xB7, &disable);
		if (disable & 0x02) {
			printk(KERN_INFO DRIVER_NAME
				": Controller already disabled. " \
				"Nothing to do.\n");
			return -ENODEV;
		}

		pci_read_config_byte(fw_dev, 0x8E, &write_enable);
		pci_write_config_byte(fw_dev, 0x8E, 0xAA);
		pci_read_config_byte(fw_dev, 0x8D, &write_target);
		pci_write_config_byte(fw_dev, 0x8D, 0xB7);
		pci_write_config_byte(fw_dev, 0xB7, disable | 0x02);
		pci_write_config_byte(fw_dev, 0x8E, write_enable);
		pci_write_config_byte(fw_dev, 0x8D, write_target);
	} else {
		/* via R5C832 */

		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);
	}

	printk(KERN_INFO DRIVER_NAME
	       ": Controller is now disabled.\n");

	return 0;
}

static int ricoh_mmc_enable(struct pci_dev *fw_dev)
{
	u8 write_enable;
	u8 write_target;
	u8 disable;

	if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
		/* via RL5C476 */

		pci_read_config_byte(fw_dev, 0x8E, &write_enable);
		pci_write_config_byte(fw_dev, 0x8E, 0xAA);
		pci_read_config_byte(fw_dev, 0x8D, &write_target);
		pci_write_config_byte(fw_dev, 0x8D, 0xB7);
		pci_read_config_byte(fw_dev, 0xB7, &disable);
		pci_write_config_byte(fw_dev, 0xB7, disable & ~0x02);
		pci_write_config_byte(fw_dev, 0x8E, write_enable);
		pci_write_config_byte(fw_dev, 0x8D, write_target);
	} else {
		/* via R5C832 */

		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");

	return 0;
}

static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
				     const struct pci_device_id *ent)
{
	u8 rev;
	u8 ctrlfound = 0;

	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_RL5C476, fw_dev))) {
		if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
		    pdev->bus == fw_dev->bus) {
			if (ricoh_mmc_disable(fw_dev) != 0)
				return -ENODEV;

			pci_set_drvdata(pdev, fw_dev);

			++ctrlfound;
			break;
		}
	}

	fw_dev = NULL;

	while (!ctrlfound &&
	    (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) {
			if (ricoh_mmc_disable(fw_dev) != 0)
				return -ENODEV;

			pci_set_drvdata(pdev, fw_dev);

			++ctrlfound;
		}
	}

	if (!ctrlfound) {
		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)
{
	struct pci_dev *fw_dev = NULL;

	fw_dev = pci_get_drvdata(pdev);
	BUG_ON(fw_dev == NULL);

	ricoh_mmc_enable(fw_dev);

	pci_set_drvdata(pdev, NULL);
}

static int ricoh_mmc_suspend(struct pci_dev *pdev, pm_message_t state)
{
	struct pci_dev *fw_dev = NULL;

	fw_dev = pci_get_drvdata(pdev);
	BUG_ON(fw_dev == NULL);

	printk(KERN_INFO DRIVER_NAME ": Suspending.\n");

	ricoh_mmc_enable(fw_dev);

	return 0;
}

static int ricoh_mmc_resume(struct pci_dev *pdev)
{
	struct pci_dev *fw_dev = NULL;

	fw_dev = pci_get_drvdata(pdev);
	BUG_ON(fw_dev == NULL);

	printk(KERN_INFO DRIVER_NAME ": Resuming.\n");

	ricoh_mmc_disable(fw_dev);

	return 0;
}

static struct pci_driver ricoh_mmc_driver = {
	.name = 	DRIVER_NAME,
	.id_table =	pci_ids,
	.probe = 	ricoh_mmc_probe,
	.remove =	__devexit_p(ricoh_mmc_remove),
	.suspend =	ricoh_mmc_suspend,
	.resume =	ricoh_mmc_resume,
};

/*****************************************************************************\
 *                                                                           *
 * 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");