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Commit 15bed0f2fa8e1d7db201692532c210a7823d2d21

Authored by Manoj Iyer
Committed by Chris Ball
1 parent 770d743200
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

mmc: Added quirks for Ricoh 1180:e823 lower base clock frequency 

Ricoh 1180:e823 does not recognize certain types of SD/MMC cards,
as reported at http://launchpad.net/bugs/773524.  Lowering the SD
base clock frequency from 200Mhz to 50Mhz fixes this issue. This
solution was suggest by Koji Matsumuro, Ricoh Company, Ltd.

This change has no negative performance effect on standard SD
cards, though it's quite possible that there will be one on
UHS-1 cards.

Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Daniel Manrique <daniel.manrique@canonical.com>
Cc: Koji Matsumuro <matsumur@nts.ricoh.co.jp>
Cc: <stable@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

Showing 1 changed file with 23 additions and 0 deletions Side-by-side Diff

drivers/pci/quirks.c
Diff comments   View file @ 15bed0f
... ... @@ -2758,6 +2758,29 @@
2758 2758  
2759 2759 dev_notice(&dev->dev, "proprietary Ricoh MMC controller disabled (via firewire function)\n");
2760 2760 dev_notice(&dev->dev, "MMC cards are now supported by standard SDHCI controller\n");
  2761 +
  2762 + /*
  2763 + * RICOH 0xe823 SD/MMC card reader fails to recognize
  2764 + * certain types of SD/MMC cards. Lowering the SD base
  2765 + * clock frequency from 200Mhz to 50Mhz fixes this issue.
  2766 + *
  2767 + * 0x150 - SD2.0 mode enable for changing base clock
  2768 + * frequency to 50Mhz
  2769 + * 0xe1 - Base clock frequency
  2770 + * 0x32 - 50Mhz new clock frequency
  2771 + * 0xf9 - Key register for 0x150
  2772 + * 0xfc - key register for 0xe1
  2773 + */
  2774 + if (dev->device == PCI_DEVICE_ID_RICOH_R5CE823) {
  2775 + pci_write_config_byte(dev, 0xf9, 0xfc);
  2776 + pci_write_config_byte(dev, 0x150, 0x10);
  2777 + pci_write_config_byte(dev, 0xf9, 0x00);
  2778 + pci_write_config_byte(dev, 0xfc, 0x01);
  2779 + pci_write_config_byte(dev, 0xe1, 0x32);
  2780 + pci_write_config_byte(dev, 0xfc, 0x00);
  2781 +
  2782 + dev_notice(&dev->dev, "MMC controller base frequency changed to 50Mhz.\n");
  2783 + }
2761 2784 }
2762 2785 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832);
2763 2786 DECLARE_PCI_FIXUP_RESUME_EARLY(PCI_VENDOR_ID_RICOH, PCI_DEVICE_ID_RICOH_R5C832, ricoh_mmc_fixup_r5c832);