On Mon, Jul 21, 2014 at 10:56:08AM +0200, Andrzej Hajda wrote: > On 07/18/2014 03:49 AM, YoungJun Cho wrote: > > Hi Thierry, > > > > Thank you a lot for kind comments. > > > > On 07/17/2014 07:36 PM, Thierry Reding wrote: > >> On Thu, Jul 17, 2014 at 06:01:25PM +0900, YoungJun Cho wrote: > >> [...] > >>> diff --git a/drivers/gpu/drm/panel/panel-s6e3fa0.c b/drivers/gpu/drm/panel/panel-s6e3fa0.c > >> [...] > >>> +/* Manufacturer Command Set */ > >>> +#define MCS_GLOBAL_PARAMETER 0xb0 > >>> +#define MCS_AID 0xb2 > >>> +#define MCS_ELVSSOPT 0xb6 > >>> +#define MCS_TEMPERATURE_SET 0xb8 > >>> +#define MCS_PENTILE_CTRL 0xc0 > >>> +#define MCS_GAMMA_MODE 0xca > >>> +#define MCS_VDDM 0xd7 > >>> +#define MCS_ALS 0xe3 > >>> +#define MCS_ERR_FG 0xed > >>> +#define MCS_KEY_LEV1 0xf0 > >>> +#define MCS_GAMMA_UPDATE 0xf7 > >>> +#define MCS_KEY_LEV2 0xfc > >>> +#define MCS_RE 0xfe > >>> +#define MCS_TOUT2_HSYNC 0xff > >>> + > >>> +/* Content Adaptive Brightness Control */ > >>> +#define DCS_WRITE_CABC 0x55 > >> Is this not a manufacturer specific command? I couldn't find it in the > >> DSI or DCS specifications, but it sounds like something standard (also > >> indicated by the DCS_ prefix). Can you point out the specification for > >> this? > >> > > Andrzej commented before and decided it as DCS one because if the value > > is less than 0xb0, it is DCS one and the others are MCS one. > > But still I'm not sure it is correct. > I would not say 'decided'. I have just stated that according to DCS > specification > it should be DCS command (below 0xb0), but it is not present in mipi dcs > specs. > On the other side many panels have it [1]: > > [1]: > https://www.google.com/search?q=%22Write+Content+Adaptive+Brightness+Control%22 Yeah, my search yielded similar results. I wonder if this is perhaps part of a draft future specification. I'll try to ask around some more if anybody knows what the status of this is. > >>> +static void s6e3fa0_read_mtp_id(struct s6e3fa0 *ctx) > >>> +{ > >>> + unsigned char id[MTP_ID_LEN]; > >>> + int ret; > >>> + > >>> + s6e3fa0_set_maximum_return_packet_size(ctx, MTP_ID_LEN); > >>> + ret = s6e3fa0_dcs_read(ctx, MIPI_DCS_GET_DISPLAY_ID, id, MTP_ID_LEN); > >> This also looks like a standard DCS command. I can't find it in either > >> v1.01 nor v1.02 of the specification, though. Do you know where it's > >> specified? > >> > > Yes, I also can't find it in DCS specification and there is no special > > description in panel datasheet. > > But as it is declared in "include/video/mipi_display.h", so I think it > > is a standard one. > > On page 9 of the "Introduction of MIPI by Renesas" [2] there is info > it is a part of "Nokia I/F command list", I guess it is kind of alpha > version of MIPI DCS. > > [2]: http://wenku.baidu.com/view/658fab68af1ffc4ffe47acbe.html That link is the only one which contains "Nokia I/F command list" on the internet (that is, according to Google). But since this is already part of the mipi_display.h header file we may as well use it. I wonder if perhaps the READ_DDB_START and READ_DDB_CONTINUE commands could be used as a replacement for this display ID. Adding Guennadi, Tomi, Paul and Imre on Cc since they were involved with the original patch that added mipi_display.h. Perhaps they remember what the origin of this command is. Thierry
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