Ricoh 1180:e823 does not recognize certain types of SD/MMC cards. Lowering the SD base clock frequency from 200Mhz to 50Mhz fixes this issue. This solution was suggest by Koji Matsumuro, Ricoh Company,Ltd. BugLink: http://launchpad.net/bugs/773524 Signed-off-by: Manoj Iyer <manoj.iyer@xxxxxxxxxxxxx> Tested-by: Daniel Manrique <daniel.manrique@xxxxxxxxxxxxx> Cc: Koji Matsumuro <matsumur@xxxxxxxxxxxxxxx> --- drivers/pci/quirks.c | 24 ++++++++++++++++++++++++ 1 files changed, 24 insertions(+), 0 deletions(-) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 02145e9..fe5bffa 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -2758,6 +2758,30 @@ static void ricoh_mmc_fixup_r5c832(struct pci_dev *dev) dev_notice(&dev->dev, "proprietary Ricoh MMC controller disabled (via firewire function)\n"); dev_notice(&dev->dev, "MMC cards are now supported by standard SDHCI controller\n"); + + /* + * RICOH 0xe823 SD/MMC card reader fails to recognize + * certain types of SD/MMC cards. Lowering the SD base + * clock frequency from 200Mhz to 50Mhz fixes this issue. + * + * 0x150 - SD2.0 mode enable for changing base clock + * frequency to 50Mhz + * 0xe1 - Base clock frequency + * 0x32 - 50Mhz new clock frequency + * 0xf9 - Key register for 0x150 + * 0xfc - key register for 0xe1 + */ + if (dev->device == PCI_DEVICE_ID_RICOH_R5CE823) { + pci_write_config_byte(dev, 0xf9, 0xfc); + pci_write_config_byte(dev, 0x150, 0x10); + pci_write_config_byte(dev, 0xf9, 0x00); + pci_write_config_byte(dev, 0xfc, 0x01); + pci_write_config_byte(dev, 0xe1, 0x32); + pci_write_config_byte(dev, 0xfc, 0x00); + + dev_notice(&dev->dev, "Controller base frequency changed to 50Mhz)\n"); + } + } DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832); DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832); -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
