Hi, sorry for bringing this thread back to live but was there any progress around with CEC and A20 chips? I can not find anything on the net so I was wondering if any of you guys managed to get any further.
El viernes, 26 de febrero de 2016, 14:38:33 (UTC+1), dk.u...@gmail.com escribió: > > пятница, 3 октября 2014 г., 21:12:33 UTC+3 пользователь Christian Ege > написал: > > Hi, > > > > Am 03.10.2014 um 09:56 schrieb Vladimir Komendantskiy: > > > > > > > > > > The Allwinner SoCs that have an HDMI pin, also have > > a memory-mapped HDMI-CEC register located at HDMI base > > 0xf1c16000 plus the offset 0x214. This register provides the > > following bits > > > > > > > > > > > > > > > > #define CEC_RX 0x0100 /* phys. line value, either > > high or low */ > > > > #define CEC_TX 0x0200 > > > > #define CEC_ENABLE 0x0800 > > > > > > > > > > > > Other bits are unused. > > > > > > > > > > > > > > I asked Allwinner about CEC once but they only replied that > > A10s doesn't have a hardware CEC core. > > > > > > > > > > > > You can find examples of using the CEC register in some > > unfinished CEC code in the 3.4 linux-sunxi kernel. > > > > > > > > > > > > > > Thx, a lot I found this PATCH > > > > > https://groups.google.com/forum/#!msg/linux-sunxi/cNbMiwzgGJ0/tK-KvXkn-pQJ > > > > > > > > And the source > > > > > https://github.com/linux-sunxi/linux-sunxi/blob/sunxi-3.4/drivers/video/sunxi/hdmi/hdmi_cec.c > > > > > > > > > I'll take a closer look on this. It looks like they do bitbanging on > > those two bits. > > > > > > > > regards, > > > > Christian > > > > > > > > > > > > > > > > --Vladimir > > > > > > > > > > > > > > > > > > > > On 3 October 2014 07:33, Chen-Yu Tsai <we...@csie.org> > > wrote: > > > > Hi, > > > > > > > > On Fri, Oct 3, 2014 at 3:29 AM, jons...@gmail.com > > <jons...@gmail.com> > > wrote: > > > > > I > > > > > > > > > > On Thu, Oct 2, 2014 at 1:19 PM, Christian Ege < > k42...@gmail.com> > > wrote: > > > > >> During a quick search I had not been able to find > > any HDMI CEC driver. In > > > > >> the docs available there is only one Register > > about CEC. > > > > >> > > > > >> I thought about implementation of an driver and > > libcec support for the A20. > > > > > > > > > > I believe CEC is just I2C on the HDMI connector. > > > > > > > > > > So maybe --- it is one of the I2C devices. Then that > > bit enables it > > > > > onto the HDMI pin? Just a guess. > > > > > > > > > > EDID works the same way. How is it implemented? > > > > > > > > You are referring to DDC. The HDMI block has a > > separate DDC controller. > > > > IIRC, the DDC pins also have standard TWI muxed on them, so > > you could > > > > use either one. > > > > > > > > But this is entirely irrelevant to the original question. > > > > > > > > As Christian stated, the HDMI block does have a register > > named > > > > HDMI_HDP_CEC. However it does not contain any useful > > descriptions. > > > > Also the SoC does have a pin for HDMI CEC. > > > > > > > > Best ask Allwinner for some help. > > > > > > > > > > > > ChenYu > > > > > > > > > > > > > > -- > > > > You received this message because you are subscribed to > > the Google Groups "linux-sunxi" group. > > > > To unsubscribe from this group and stop receiving emails > > from it, send an email to > linux-sunxi...@googlegroups.com. > > > > For more options, visit > https://groups.google.com/d/optout. > > > > > > > > > > > > > > > > > > -- > > > > You received this message because you are subscribed to the Google > > Groups "linux-sunxi" group. > > > > To unsubscribe from this group and stop receiving emails from it, > > send an email to linux-sunxi...@googlegroups.com. > > > > For more options, visit https://groups.google.com/d/optout. > > so, how i can use CEC on A20? > i call: > modprobe hdmi-cec > and then no see any new devices in /dev > -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
