diff options
Diffstat (limited to 'drivers/mmc/host/ricoh_mmc.c')
| -rw-r--r-- | drivers/mmc/host/ricoh_mmc.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/mmc/host/ricoh_mmc.c b/drivers/mmc/host/ricoh_mmc.c index a16d7609e4e..be9e7b32b34 100644 --- a/drivers/mmc/host/ricoh_mmc.c +++ b/drivers/mmc/host/ricoh_mmc.c @@ -11,9 +11,10 @@ /* * 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 + * the Ricoh multi-function chips (R5CXXX) work. These chips implement + * the four main memory card controllers (SD, MMC, MS, xD) and one or both + * of cardbus or firewire. It happens that they implement SD and MMC + * support as separate controllers (and PCI functions). 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. @@ -21,8 +22,10 @@ * 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. + * It seems to be the case that the relevant PCI registers to deactivate the + * MMC controller live on PCI function 0, which might be the cardbus controller + * or the firewire controller, depending on the particular chip in question. As + * such, it makes what this driver has to do unavoidably ugly. Such is life. */ #include <linux/pci.h> @@ -143,6 +146,7 @@ static int __devinit ricoh_mmc_probe(struct pci_dev *pdev, pci_get_device(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_RL5C476, fw_dev))) { if (PCI_SLOT(pdev->devfn) == PCI_SLOT(fw_dev->devfn) && + PCI_FUNC(fw_dev->devfn) == 0 && pdev->bus == fw_dev->bus) { if (ricoh_mmc_disable(fw_dev) != 0) return -ENODEV; @@ -160,6 +164,7 @@ static int __devinit ricoh_mmc_probe(struct pci_dev *pdev, (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) && + PCI_FUNC(fw_dev->devfn) == 0 && pdev->bus == fw_dev->bus) { if (ricoh_mmc_disable(fw_dev) != 0) return -ENODEV; @@ -172,7 +177,7 @@ static int __devinit ricoh_mmc_probe(struct pci_dev *pdev, if (!ctrlfound) { printk(KERN_WARNING DRIVER_NAME - ": Main firewire function not found. Cannot disable controller.\n"); + ": Main Ricoh function not found. Cannot disable controller.\n"); return -ENODEV; } |