Re: [PATCH v5 3/4] drm/bridge: Introduce LT9611 DSI to HDMI bridge

Laurent Pinchart
2020-07-22T13:14:39Z

Hello,

On Sun, Jul 19, 2020 at 07:18:06PM +0200, Sam Ravnborg wrote:
> Hi Vinod.
>
> Three trivial points below.
> The rest looks good.
>
> With these fixed you can add:
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
>
> Sam
>
> On Wed, Jul 08, 2020 at 04:05:58PM +0530, Vinod Koul wrote:
> > Lontium Lt9611 is a DSI to HDMI bridge which supports two DSI ports and
> > I2S port as an input and HDMI port as output
> >
> > Co-developed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > Co-developed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > Tested-by: John Stultz <john.stultz@linaro.org>
> > Signed-off-by: Vinod Koul <vkoul@kernel.org>
> > ---
> > drivers/gpu/drm/bridge/Kconfig | 13 +
> > drivers/gpu/drm/bridge/Makefile | 1 +
> > drivers/gpu/drm/bridge/lontium-lt9611.c | 1142 +++++++++++++++++++++++
> > 3 files changed, 1156 insertions(+)
> > create mode 100644 drivers/gpu/drm/bridge/lontium-lt9611.c
> >
> > +
> > +#include <drm/drm_probe_helper.h>
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_bridge.h>
> > +#include <drm/drm_mipi_dsi.h>
> > +#include <drm/drm_print.h>
>
> In alphabetical order. drm_probe_helper needs to be moved.
>
> > +
> > +#define EDID_SEG_SIZE 256
> > +#define EDID_LEN 32
> > +#define EDID_LOOP 8
> > +#define KEY_DDC_ACCS_DONE 0x02
> > +#define DDC_NO_ACK 0x50
> > +
>
> > +static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mode *mode)
> > +{
> > + const struct reg_sequence reg_cfg[] = {
> > + { 0x830b, 0x01 },
> > + { 0x830c, 0x10 },
> > + { 0x8348, 0x00 },
> > + { 0x8349, 0x81 },
> > +
> > + /* stage 1 */
> > + { 0x8321, 0x4a },
> > + { 0x8324, 0x71 },
> > + { 0x8325, 0x30 },
> > + { 0x832a, 0x01 },
> > +
> > + /* stage 2 */
> > + { 0x834a, 0x40 },
> > + { 0x831d, 0x10 },
> > +
> > + /* MK limit */
> > + { 0x832d, 0x38 },
> > + { 0x8331, 0x08 },
> > + };
> > + const struct reg_sequence reg_cfg2[] = {
> > + { 0x830b, 0x03 },
> > + { 0x830c, 0xd0 },
> > + { 0x8348, 0x03 },
> > + { 0x8349, 0xe0 },
> > + { 0x8324, 0x72 },
> > + { 0x8325, 0x00 },
> > + { 0x832a, 0x01 },
> > + { 0x834a, 0x10 },
> > + { 0x831d, 0x10 },
> > + { 0x8326, 0x37 },
>
> Block above is indented one tab too much.
>
> > +static int lt9611_bridge_attach(struct drm_bridge *bridge,
> > + enum drm_bridge_attach_flags flags)
> > +{
> > + struct lt9611 *lt9611 = bridge_to_lt9611(bridge);
> > + int ret;
> > +
> > + if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
> > + dev_err(lt9611->dev, "Fix bridge driver to make connector optional!");
> > + return -EINVAL;
> > + }
>
> This should say that the display driver should be fixed.
> If a display driver expects this bridge to create the connector
> it would not work.

Actually, for new bridge drivers, connector creation should be optional
from the start. We don't want a failure in that case, the feature should
be implemented.

--
Regards,

Laurent Pinchart