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 ricoh_mmc_disable(struct pci_dev *fw_dev)
  45 {
  46         u8 write_enable;
  47         u8 write_target;
  48         u8 disable;
  49
  50         if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
  51                 /* via RL5C476 */
  52
  53                 pci_read_config_byte(fw_dev, 0xB7, &disable);
  54                 if (disable & 0x02) {
  55                         printk(KERN_INFO DRIVER_NAME
  56                                 ": Controller already disabled. " \
  57                                 "Nothing to do.\n");
  58                         return -ENODEV;
  59                 }
  60
  61                 pci_read_config_byte(fw_dev, 0x8E, &write_enable);
  62                 pci_write_config_byte(fw_dev, 0x8E, 0xAA);
  63                 pci_read_config_byte(fw_dev, 0x8D, &write_target);
  64                 pci_write_config_byte(fw_dev, 0x8D, 0xB7);
  65                 pci_write_config_byte(fw_dev, 0xB7, disable | 0x02);
  66                 pci_write_config_byte(fw_dev, 0x8E, write_enable);
  67                 pci_write_config_byte(fw_dev, 0x8D, write_target);
  68         } else {
  69                 /* via R5C832 */
  70
  71                 pci_read_config_byte(fw_dev, 0xCB, &disable);
  72                 if (disable & 0x02) {
  73                         printk(KERN_INFO DRIVER_NAME
  74                                ": Controller already disabled. " \
  75                                 "Nothing to do.\n");
  76                         return -ENODEV;
  77                 }
  78
  79                 pci_read_config_byte(fw_dev, 0xCA, &write_enable);
  80                 pci_write_config_byte(fw_dev, 0xCA, 0x57);
  81                 pci_write_config_byte(fw_dev, 0xCB, disable | 0x02);
  82                 pci_write_config_byte(fw_dev, 0xCA, write_enable);
  83         }
  84
  85         printk(KERN_INFO DRIVER_NAME
  86                ": Controller is now disabled.\n");
  87
  88         return 0;
  89 }
  90
  91 static int ricoh_mmc_enable(struct pci_dev *fw_dev)
  92 {
  93         u8 write_enable;
  94         u8 write_target;
  95         u8 disable;
  96
  97         if (fw_dev->device == PCI_DEVICE_ID_RICOH_RL5C476) {
  98                 /* via RL5C476 */
  99
 100                 pci_read_config_byte(fw_dev, 0x8E, &write_enable);
 101                 pci_write_config_byte(fw_dev, 0x8E, 0xAA);
 102                 pci_read_config_byte(fw_dev, 0x8D, &write_target);
 103                 pci_write_config_byte(fw_dev, 0x8D, 0xB7);
 104                 pci_read_config_byte(fw_dev, 0xB7, &disable);
 105                 pci_write_config_byte(fw_dev, 0xB7, disable & ~0x02);
 106                 pci_write_config_byte(fw_dev, 0x8E, write_enable);
 107                 pci_write_config_byte(fw_dev, 0x8D, write_target);
 108         } else {
 109                 /* via R5C832 */
 110
 111                 pci_read_config_byte(fw_dev, 0xCA, &write_enable);
 112                 pci_read_config_byte(fw_dev, 0xCB, &disable);
 113                 pci_write_config_byte(fw_dev, 0xCA, 0x57);
 114                 pci_write_config_byte(fw_dev, 0xCB, disable & ~0x02);
 115                 pci_write_config_byte(fw_dev, 0xCA, write_enable);
 116         }
 117
 118         printk(KERN_INFO DRIVER_NAME
 119                ": Controller is now re-enabled.\n");
 120
 121         return 0;
 122 }
 123
 124 static int __devinit ricoh_mmc_probe(struct pci_dev *pdev,
 125                                      const struct pci_device_id *ent)
 126 {
 127         u8 rev;
 128         u8 ctrlfound = 0;
 129
 130         struct pci_dev *fw_dev = NULL;
 131
 132         BUG_ON(pdev == NULL);
 133         BUG_ON(ent == NULL);
 134
 135         pci_read_config_byte(pdev, PCI_CLASS_REVISION, &rev);
 136
 137         printk(KERN_INFO DRIVER_NAME
 138                 ": Ricoh MMC controller found at %s [%04x:%04x] (rev %x)\n",
 139                 pci_name(pdev), (int)pdev->vendor, (int)pdev->device,
 140                 (int)rev);
 141
 142         while ((fw_dev =
 143                 pci_get_device(PCI_VENDOR_ID_RICOH,
 144                         PCI_DEVICE_ID_RICOH_RL5C476, fw_dev))) {
 145                 if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
 146                     pdev->bus == fw_dev->bus) {
 147                         if (ricoh_mmc_disable(fw_dev) != 0)
 148                                 return -ENODEV;
 149
 150                         pci_set_drvdata(pdev, fw_dev);
 151
 152                         ++ctrlfound;
 153                         break;
 154                 }
 155         }
 156
 157         fw_dev = NULL;
 158
 159         while (!ctrlfound &&
 160             (fw_dev = pci_get_device(PCI_VENDOR_ID_RICOH,
 161                                         PCI_DEVICE_ID_RICOH_R5C832, fw_dev))) {
 162                 if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) &&
 163                     pdev->bus == fw_dev->bus) {
 164                         if (ricoh_mmc_disable(fw_dev) != 0)
 165                                 return -ENODEV;
 166
 167                         pci_set_drvdata(pdev, fw_dev);
 168
 169                         ++ctrlfound;
 170                 }
 171         }
 172
 173         if (!ctrlfound) {
 174                 printk(KERN_WARNING DRIVER_NAME
 175                        ": Main firewire function not found. Cannot disable controller.\n");
 176                 return -ENODEV;
 177         }
 178
 179         return 0;
 180 }
 181
 182 static void __devexit ricoh_mmc_remove(struct pci_dev *pdev)
 183 {
 184         struct pci_dev *fw_dev = NULL;
 185
 186         fw_dev = pci_get_drvdata(pdev);
 187         BUG_ON(fw_dev == NULL);
 188
 189         ricoh_mmc_enable(fw_dev);
 190
 191         pci_set_drvdata(pdev, NULL);
 192 }
 193
 194 static int ricoh_mmc_suspend(struct pci_dev *pdev, pm_message_t state)
 195 {
 196         struct pci_dev *fw_dev = NULL;
 197
 198         fw_dev = pci_get_drvdata(pdev);
 199         BUG_ON(fw_dev == NULL);
 200
 201         printk(KERN_INFO DRIVER_NAME ": Suspending.\n");
 202
 203         ricoh_mmc_enable(fw_dev);
 204
 205         return 0;
 206 }
 207
 208 static int ricoh_mmc_resume(struct pci_dev *pdev)
 209 {
 210         struct pci_dev *fw_dev = NULL;
 211
 212         fw_dev = pci_get_drvdata(pdev);
 213         BUG_ON(fw_dev == NULL);
 214
 215         printk(KERN_INFO DRIVER_NAME ": Resuming.\n");
 216
 217         ricoh_mmc_disable(fw_dev);
 218
 219         return 0;
 220 }
 221
 222 static struct pci_driver ricoh_mmc_driver = {
 223         .name =         DRIVER_NAME,
 224         .id_table =     pci_ids,
 225         .probe =        ricoh_mmc_probe,
 226         .remove =       __devexit_p(ricoh_mmc_remove),
 227         .suspend =      ricoh_mmc_suspend,
 228         .resume =       ricoh_mmc_resume,
 229 };
 230
 231 /*****************************************************************************\
 232  *                                                                           *
 233  * Driver init/exit                                                          *
 234  *                                                                           *
 235 \*****************************************************************************/
 236
 237 static int __init ricoh_mmc_drv_init(void)
 238 {
 239         printk(KERN_INFO DRIVER_NAME
 240                 ": Ricoh MMC Controller disabling driver\n");
 241         printk(KERN_INFO DRIVER_NAME ": Copyright(c) Philip Langdale\n");
 242
 243         return pci_register_driver(&ricoh_mmc_driver);
 244 }
 245
 246 static void __exit ricoh_mmc_drv_exit(void)
 247 {
 248         pci_unregister_driver(&ricoh_mmc_driver);
 249 }
 250
 251 module_init(ricoh_mmc_drv_init);
 252 module_exit(ricoh_mmc_drv_exit);
 253
 254 MODULE_AUTHOR("Philip Langdale <philipl@alumni.utexas.net>");
 255 MODULE_DESCRIPTION("Ricoh MMC Controller disabling driver");
 256 MODULE_LICENSE("GPL");
 257