linux-kernel - Re: [PATCH v4 3/8] usb: pd: Make SVDM Version configurable in VDM header

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Date:   Tue, 2 Feb 2021 06:50:04 -0800
From:   Guenter Roeck <linux@...ck-us.net>
To:     Kyle Tso <kyletso@...gle.com>, heikki.krogerus@...ux.intel.com,
        gregkh@...uxfoundation.org, hdegoede@...hat.com, robh+dt@...nel.org
Cc:     badhri@...gle.com, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v4 3/8] usb: pd: Make SVDM Version configurable in VDM
 header

On 2/2/21 1:33 AM, Kyle Tso wrote:
> PD Rev 3.0 introduces SVDM Version 2.0. This patch makes the field
> configuable in the header in order to be able to be compatible with
> older SVDM version.
> 
> Signed-off-by: Kyle Tso <kyletso@...gle.com>
> ---
>  include/linux/usb/pd_vdo.h | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/usb/pd_vdo.h b/include/linux/usb/pd_vdo.h
> index e9b6822c54c2..69ed6929ce6e 100644
> --- a/include/linux/usb/pd_vdo.h
> +++ b/include/linux/usb/pd_vdo.h
> @@ -21,22 +21,24 @@
>   * ----------
>   * <31:16>  :: SVID
>   * <15>     :: VDM type ( 1b == structured, 0b == unstructured )
> - * <14:13>  :: Structured VDM version (can only be 00 == 1.0 currently)
> + * <14:13>  :: Structured VDM version
>   * <12:11>  :: reserved
>   * <10:8>   :: object position (1-7 valid ... used for enter/exit mode only)
>   * <7:6>    :: command type (SVDM only?)
>   * <5>      :: reserved (SVDM), command type (UVDM)
>   * <4:0>    :: command
>   */
> -#define VDO(vid, type, custom)				\
> +#define VDO(vid, type, ver, custom)			\
>  	(((vid) << 16) |				\
>  	 ((type) << 15) |				\
> +	 ((ver) << 13) |				\
>  	 ((custom) & 0x7FFF))
>  

Yu have to fix all users of VDO() as well, or the code will
no longer compile after this patch.

Guenter

>  #define VDO_SVDM_TYPE		(1 << 15)
>  #define VDO_SVDM_VERS(x)	((x) << 13)
>  #define VDO_OPOS(x)		((x) << 8)
>  #define VDO_CMDT(x)		((x) << 6)
> +#define VDO_SVDM_VERS_MASK	VDO_SVDM_VERS(0x3)
>  #define VDO_OPOS_MASK		VDO_OPOS(0x7)
>  #define VDO_CMDT_MASK		VDO_CMDT(0x3)
>  
> @@ -74,6 +76,7 @@
>  
>  #define PD_VDO_VID(vdo)		((vdo) >> 16)
>  #define PD_VDO_SVDM(vdo)	(((vdo) >> 15) & 1)
> +#define PD_VDO_SVDM_VER(vdo)	(((vdo) >> 13) & 0x3)
>  #define PD_VDO_OPOS(vdo)	(((vdo) >> 8) & 0x7)
>  #define PD_VDO_CMD(vdo)		((vdo) & 0x1f)
>  #define PD_VDO_CMDT(vdo)	(((vdo) >> 6) & 0x3)
>