Hi Inki, +CC: Thierry and Alexandre On 07/18/2014 12:56 PM, Inki Dae wrote: > This patch adds below two flags for LPM transfer, and it attaches LPM flags > to a msg in accordance with master's mode_flags set by LCD Panel driver. > > MIPI_DSI_MODE_CMD_LPM: low power command transfer > MIPI_DSI_MODE_VIDEO_LPM: low power video transfer What is the difference between these two? Why not just MIPI_DSI_MODE_LPM combined optionally with MIPI_DSI_MODE_VIDEO ? Anyway as I understand the only role of this flag is to always trigger MIPI_DSI_MSG_USE_LPM flag in DSI message. Maybe better is to check both flags in DSI host, using some helper function. > > MIPI DSI spec says, > "the host processor controls the desired mode of clock operation. > Host protocol and applications control Clock Lane operating mode > (High Speed or Low Power mode). System designers are responsible > for understanding the clock requirements for peripherals attached > to DSI and controlling clock behavior in accordance with those > requirements." > > Some LCD Panel devices, nt35502a, would need LPM transfer support > because they should receive some initial commands with LPM by default > hardware setting. It would be good to see usage of this flag in the driver. Is it possible to post it? I have posted few months ago TC358764 driver[1] which also uses LPM for initialization, have you look at it. [1]: http://lists.freedesktop.org/archives/dri-devel/2014-February/053713.html Regards Andrzej > > Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx> > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > --- > drivers/gpu/drm/drm_mipi_dsi.c | 3 +++ > include/drm/drm_mipi_dsi.h | 4 ++++ > 2 files changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c > index e633df2..6b2bbda 100644 > --- a/drivers/gpu/drm/drm_mipi_dsi.c > +++ b/drivers/gpu/drm/drm_mipi_dsi.c > @@ -232,6 +232,9 @@ int mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, unsigned int channel, > break; > } > > + if (dsi->mode_flags & MIPI_DSI_MODE_CMD_LPM) > + msg.flags = MIPI_DSI_MSG_USE_LPM; > + > return ops->transfer(dsi->host, &msg); > } > EXPORT_SYMBOL(mipi_dsi_dcs_write); > diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h > index 944f33f..1c41e49 100644 > --- a/include/drm/drm_mipi_dsi.h > +++ b/include/drm/drm_mipi_dsi.h > @@ -94,6 +94,10 @@ void mipi_dsi_host_unregister(struct mipi_dsi_host *host); > #define MIPI_DSI_MODE_VSYNC_FLUSH BIT(8) > /* disable EoT packets in HS mode */ > #define MIPI_DSI_MODE_EOT_PACKET BIT(9) > +/* command low power mode */ > +#define MIPI_DSI_MODE_CMD_LPM BIT(10) > +/* video low power mode */ > +#define MIPI_DSI_MODE_VIDEO_LPM BIT(11) > > enum mipi_dsi_pixel_format { > MIPI_DSI_FMT_RGB888, -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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