On Tue, 3 Jul 2012 10:12:09 +0200, Yegor Yefremov wrote: > I'm using the second i2c channel to connect to HDMI transmitter > sii9022a. In order to get EDID information from the attached monitor > the sii9022a chip passes i2c request direct to the monitors i2c bus. > To return to sii9022a mode one has to write data to HDMI transmitter, > but this data won't be acknowledged. Because of this i2c produces > timeout permanently (omap_i2c omap_i2c.2: controller timed out), so no > communication is possible. The last bits I see on the scope are the > i2c address of sii9022a. The CPU automatically end the transfer. > > The HDMI chip has i2c address 0x72 (8-bit notation) and EDID channel > 0xa0 (8-bit notation). AFAIK there is only one device at a time on the > bus, i.e. as soon as I switch sii9022a to access monitor only 0xa0 > responds to the queries. And I need to send a message to 0x72 ignoring > normal i2c conditions in order to turn it back in normal mode. > > The driver for this HDMI transmitter can be found here: > http://gitorious.org/efikamx/linux-kernel.git > (drivers/video/mxc/siihdmi.c) > > How can I send this write request without awaiting for ACK? Use I2C_M_IGNORE_NAK, see Documentation/i2c/i2c-protocol. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
