Hi, While looking into a report by Florian Vaussard [1] I have noticed couple of most likely unrelated issues: - all boards using twl6040 configures the i2c bus to 400KHz while twl6040 is set to 100KHz as default. - if I set the audpwron GPIO high [2] in the bootloader the i2c communication towards twl6040 will be broken - got confirmation from HW design teams that twl6040 can work on a bus with 400KHz even if after hard reset but it is optimal to swithc to 400KHz mode as soon as possible.
The solution or these are: set the twl6040 to i2c fast mode with regmap patch Clear the INTID register right after we request the audpwron GPIO and set it to low. Generated on top of: git://git.linaro.org/people/lee.jones/mfd.git for-mfd-next Tested on PandaBoard, PandaBoardES, OMAP4-blaze (SDP) [1] http://www.spinics.net/lists/arm-kernel/msg310725.html [2] Command in u-boot to enable the audpwron on PandaBoards: gpio set 127 Regards, Peter --- Peter Ujfalusi (3): mfd: twl6040: Select i2c fast mode as default with regmap patch mfd: twl6040: Move register patching earlier in probe mfd: twl6040: Clear the interrupt ID register before requesting IRQ drivers/mfd/twl6040.c | 19 +++++++++++++------ include/linux/mfd/twl6040.h | 1 + 2 files changed, 14 insertions(+), 6 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
