X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;ds=sidebyside;f=drivers%2Fpci%2Fquirks.c;h=1196f61a4ab6b2dabab0faacd1cbde65bf53af9a;hb=eebb6fb4ae2f60a82e38afb6d8b373a4216bf891;hp=02145e9697a9709fbcd615fb9597033f57e491dd;hpb=4d09a938861ef16248334d57ae250e109b0004ae;p=karo-tx-linux.git

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 02145e9697a9..1196f61a4ab6 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2758,6 +2758,29 @@ 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, "MMC 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);