Re: [PATCHv9 14/15] cec: s5p-cec: Add s5p-cec driver

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Mon, Oct 12, 2015 at 02:39:42PM +0200, Hans Verkuil wrote:
> On 10/12/2015 02:33 PM, Kamil Debski wrote:
> > The possible status values that are implemented in the CEC framework
> > are following:
> > 
> > +/* cec status field */
> > +#define CEC_TX_STATUS_OK               (0)
> > +#define CEC_TX_STATUS_ARB_LOST         (1 << 0)
> > +#define CEC_TX_STATUS_RETRY_TIMEOUT    (1 << 1)
> > +#define CEC_TX_STATUS_FEATURE_ABORT    (1 << 2)
> > +#define CEC_TX_STATUS_REPLY_TIMEOUT    (1 << 3)
> > +#define CEC_RX_STATUS_READY            (0)
> > 
> > The only two ones I could match with the Exynos CEC module status bits are
> > CEC_TX_STATUS_OK and  CEC_TX_STATUS_RETRY_TIMEOUT.
> > 
> > The status bits in Exynos HW are:
> > - Tx_Error
> > - Tx_Done
> > - Tx_Transferring
> > - Tx_Running
> > - Tx_Bytes_Transferred
> > 
> > - Tx_Wait
> > - Tx_Sending_Status_Bit
> > - Tx_Sending_Hdr_Blk
> > - Tx_Sending_Data_Blk
> > - Tx_Latest_Initiator
> > 
> > - Tx_Wait_SFT_Succ
> > - Tx_Wait_SFT_New
> > - Tx_Wait_SFT_Retran
> > - Tx_Retrans_Cnt
> > - Tx_ACK_Failed
> 
> So are these all intermediate states? And every transfer always ends with Tx_Done or
> Tx_Error state?
> 
> It does look that way...

For the Synopsis DW CEC, I have:

Bit Field	Description
4   ERROR_INIT	An error is detected on cec line (for initiator only).
3   ARB_LOST	The initiator losses the CEC line arbitration to a second
		initiator. (specification CEC 9).
2   NACK	A frame is not acknowledged in a directly addressed message.
		Or a frame is negatively acknowledged in a broadcast message
		(for initiator only).
0   DONE	The current transmission is successful (for initiator only).

That's about as much of a description that there is for this hardware.
Quite what comprises an "ERROR_INIT", I don't know.

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