[PATCH 0/3] mmc: sdhci: Dual Data Rate Support Patch set 9/12 [PATCH 1/4] mmc: rename ddr to uhs in ios structure to indicate usage uhs mode comprises dual data rate, single data rate options such as ddr_1_8v as well as sdr50 and sdr104 ddr name changed to indicate its true usage [PATCH 2/4] sdhci: register defs for sd 3.0 HOST CONTROL 2 Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx> Signed-off-by: Mark F. Brown <markb@xxxxxxxxxxx> [PATCH 3/4] mmc: sdhci: Support for SD/MMC Dual Data Rate ** V4 Changes ** sdhci set_ddr does not change signaling voltage when core/ layer indicates this is not needed. eMMC cards working at 3.3V do not need to have their i/o signaling level changed since they are obviously working and 3.3v or lower vccq is supported. (we do not know if a 3.3V card supports 1.8V vccq). Similarly eMMC cards working at 1.8V do not need their signaling voltage changed. The DDR value on the card only tells us it works at 1.8V or 3.3V or both. eMMC Voltage (vcc) and i/o signaling (vccq) allowed vcc 3.3V 3.3v vccq - 1.8v vccq - 1.2v vccq 1.8V - 1.8v vccq - 1.2v vccq 1.2V - 1.2v vccq We have a single voltage eMMC (which is all we support since dual voltage cards are not supported). We have no idea what vccq it is operating at. eMMC cards are usually mounted on the board. For a eMMC not operating at 1.2V vccq we signal the host/ layer to leave the signaling voltage alone since we are obviously working. We have no idea if switching the card to 1.8V vccq is supported by the card. If the eMMC card indicates it supports 1.2V vccq we notify the driver since 1.2V core voltage (vcc) is not supported and a i/o signal voltage change will be needed. Note: SD Host Controller (sdhci.c) does not support 1.2V vcc. Rules for SD DDR are different. vccq change occurs after a CMD11. ddr renamed to uhs. [PATCH 4/4] sdhci: sdhci-pxa.c: add callback for signaling for DDR controller needs to have 1.8V signaling voltage bit set even if not doing 1.8V signaling for DDR to work. The bit does not change the i/o signaling voltage -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
