diff mbox series

[v2,2/9] drm/bridge: synopsys: dw-mipi-dsi: Add input bus format negotiation support

Message ID 20230720071430.259892-3-victor.liu@nxp.com (mailing list archive)
State New, archived
Headers show
Series drm/bridge: imx: Add i.MX93 MIPI DSI support | expand

Commit Message

Ying Liu July 20, 2023, 7:10 a.m. UTC
Introduce ->get_input_bus_fmts() callback to struct dw_mipi_dsi_plat_data
so that vendor drivers can implement specific methods to get input bus
formats for Synopsys DW MIPI DSI.

While at it, implement a generic callback for ->atomic_get_input_bus_fmts(),
where we try to get the input bus formats through pdata->get_input_bus_fmts()
first.  If it's unavailable, fall back to the only format - MEDIA_BUS_FMT_FIXED,
which matches the default behavior if ->atomic_get_input_bus_fmts() is not
implemented as ->atomic_get_input_bus_fmts()'s kerneldoc indicates.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v1->v2:
* No change.

 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 30 +++++++++++++++++++
 include/drm/bridge/dw_mipi_dsi.h              | 11 +++++++
 2 files changed, 41 insertions(+)

Comments

Jagan Teki July 30, 2023, 6:43 p.m. UTC | #1
On Thu, Jul 20, 2023 at 12:40 PM Ying Liu <victor.liu@nxp.com> wrote:
>
> Introduce ->get_input_bus_fmts() callback to struct dw_mipi_dsi_plat_data
> so that vendor drivers can implement specific methods to get input bus
> formats for Synopsys DW MIPI DSI.
>
> While at it, implement a generic callback for ->atomic_get_input_bus_fmts(),
> where we try to get the input bus formats through pdata->get_input_bus_fmts()
> first.  If it's unavailable, fall back to the only format - MEDIA_BUS_FMT_FIXED,
> which matches the default behavior if ->atomic_get_input_bus_fmts() is not
> implemented as ->atomic_get_input_bus_fmts()'s kerneldoc indicates.
>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v1->v2:
> * No change.
>
>  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 30 +++++++++++++++++++
>  include/drm/bridge/dw_mipi_dsi.h              | 11 +++++++
>  2 files changed, 41 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 57eae0fdd970..8580b8a97fb1 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -12,6 +12,7 @@
>  #include <linux/component.h>
>  #include <linux/debugfs.h>
>  #include <linux/iopoll.h>
> +#include <linux/media-bus-format.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> @@ -536,6 +537,34 @@ static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
>         .transfer = dw_mipi_dsi_host_transfer,
>  };
>
> +static u32 *
> +dw_mipi_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +                                            struct drm_bridge_state *bridge_state,
> +                                            struct drm_crtc_state *crtc_state,
> +                                            struct drm_connector_state *conn_state,
> +                                            u32 output_fmt,
> +                                            unsigned int *num_input_fmts)
> +{
> +       struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
> +       const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
> +       u32 *input_fmts;
> +
> +       if (pdata->get_input_bus_fmts)
> +               return pdata->get_input_bus_fmts(pdata->priv_data,
> +                                                bridge, bridge_state,
> +                                                crtc_state, conn_state,
> +                                                output_fmt, num_input_fmts);

Why do we need platform-controlled bus formats? The supported bridge
formats are common across all platforms and it is specific to the list
of formats supported by DW-MIPI DSI. isn't it?

Thanks,
Jagan.
Ying Liu July 31, 2023, 3:38 a.m. UTC | #2
On Monday, July 31, 2023 2:44 AM Jagan Teki <jagan@amarulasolutions.com> wrote:
> 
> On Thu, Jul 20, 2023 at 12:40 PM Ying Liu <victor.liu@nxp.com> wrote:
> >
> > Introduce ->get_input_bus_fmts() callback to struct dw_mipi_dsi_plat_data
> > so that vendor drivers can implement specific methods to get input bus
> > formats for Synopsys DW MIPI DSI.
> >
> > While at it, implement a generic callback for -
> >atomic_get_input_bus_fmts(),
> > where we try to get the input bus formats through pdata-
> >get_input_bus_fmts()
> > first.  If it's unavailable, fall back to the only format -
> MEDIA_BUS_FMT_FIXED,
> > which matches the default behavior if ->atomic_get_input_bus_fmts() is
> not
> > implemented as ->atomic_get_input_bus_fmts()'s kerneldoc indicates.
> >
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > v1->v2:
> > * No change.
> >
> >  drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 30
> +++++++++++++++++++
> >  include/drm/bridge/dw_mipi_dsi.h              | 11 +++++++
> >  2 files changed, 41 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > index 57eae0fdd970..8580b8a97fb1 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> > @@ -12,6 +12,7 @@
> >  #include <linux/component.h>
> >  #include <linux/debugfs.h>
> >  #include <linux/iopoll.h>
> > +#include <linux/media-bus-format.h>
> >  #include <linux/module.h>
> >  #include <linux/of_device.h>
> >  #include <linux/pm_runtime.h>
> > @@ -536,6 +537,34 @@ static const struct mipi_dsi_host_ops
> dw_mipi_dsi_host_ops = {
> >         .transfer = dw_mipi_dsi_host_transfer,
> >  };
> >
> > +static u32 *
> > +dw_mipi_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge
> *bridge,
> > +                                            struct drm_bridge_state *bridge_state,
> > +                                            struct drm_crtc_state *crtc_state,
> > +                                            struct drm_connector_state *conn_state,
> > +                                            u32 output_fmt,
> > +                                            unsigned int *num_input_fmts)
> > +{
> > +       struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
> > +       const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
> > +       u32 *input_fmts;
> > +
> > +       if (pdata->get_input_bus_fmts)
> > +               return pdata->get_input_bus_fmts(pdata->priv_data,
> > +                                                bridge, bridge_state,
> > +                                                crtc_state, conn_state,
> > +                                                output_fmt, num_input_fmts);
> 
> Why do we need platform-controlled bus formats? The supported bridge
> formats are common across all platforms and it is specific to the list
> of formats supported by DW-MIPI DSI. isn't it?

Ideally, yes.  But, if we consider some SoC logics introduced due to
DW MIPI DSI integration(like the DISPLAY_MUX register in i.MX93
media blk-ctrl as a syscon), then pdata->get_input_bus_fmts is handy
to cover the logics. Meson's MIPI_DSI_TOP_CNTL register and stm's
DSI_WCFGR register are the similar cases for integration.  Rockchip
directly sets display controller's output bus format in ->atomic_check().

Granted those SoC logics can be a standalone DRM bridge as the previous
bridge of the DW MIPI DSI bridge.  However, the question is that are the
logics worth a separate DRM bridge driver, considering
pdata->get_input_bus_fmts is quite handy?

Implementing a separate DRM bridge driver for i.MX93 DISPLAY_MUX
to add two DRM bridges is a bit hard, because the single register controls
both external parallel display pixel format and DSI controller input pixel
format with different bit fields.  And, I've already sent a patch series[1]
to add a DRM bridge driver for the external parallel display pixel format
control.

[1] https://patchwork.freedesktop.org/series/113457/

Regards,
Liu Ying

> 
> Thanks,
> Jagan.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 57eae0fdd970..8580b8a97fb1 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -12,6 +12,7 @@ 
 #include <linux/component.h>
 #include <linux/debugfs.h>
 #include <linux/iopoll.h>
+#include <linux/media-bus-format.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
@@ -536,6 +537,34 @@  static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
 	.transfer = dw_mipi_dsi_host_transfer,
 };
 
+static u32 *
+dw_mipi_dsi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+					     struct drm_bridge_state *bridge_state,
+					     struct drm_crtc_state *crtc_state,
+					     struct drm_connector_state *conn_state,
+					     u32 output_fmt,
+					     unsigned int *num_input_fmts)
+{
+	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
+	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
+	u32 *input_fmts;
+
+	if (pdata->get_input_bus_fmts)
+		return pdata->get_input_bus_fmts(pdata->priv_data,
+						 bridge, bridge_state,
+						 crtc_state, conn_state,
+						 output_fmt, num_input_fmts);
+
+	/* Fall back to MEDIA_BUS_FMT_FIXED as the only input format. */
+	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+	input_fmts[0] = MEDIA_BUS_FMT_FIXED;
+	*num_input_fmts = 1;
+
+	return input_fmts;
+}
+
 static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
 {
 	u32 val;
@@ -1003,6 +1032,7 @@  static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge,
 static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
 	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts = dw_mipi_dsi_bridge_atomic_get_input_bus_fmts,
 	.atomic_reset		= drm_atomic_helper_bridge_reset,
 	.atomic_enable		= dw_mipi_dsi_bridge_atomic_enable,
 	.atomic_post_disable	= dw_mipi_dsi_bridge_post_atomic_disable,
diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
index f54621b17a69..246650f2814f 100644
--- a/include/drm/bridge/dw_mipi_dsi.h
+++ b/include/drm/bridge/dw_mipi_dsi.h
@@ -11,7 +11,10 @@ 
 
 #include <linux/types.h>
 
+#include <drm/drm_atomic.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc.h>
 #include <drm/drm_modes.h>
 
 struct drm_display_mode;
@@ -56,6 +59,14 @@  struct dw_mipi_dsi_plat_data {
 					   unsigned long mode_flags,
 					   u32 lanes, u32 format);
 
+	u32 *(*get_input_bus_fmts)(void *priv_data,
+				   struct drm_bridge *bridge,
+				   struct drm_bridge_state *bridge_state,
+				   struct drm_crtc_state *crtc_state,
+				   struct drm_connector_state *conn_state,
+				   u32 output_fmt,
+				   unsigned int *num_input_fmts);
+
 	const struct dw_mipi_dsi_phy_ops *phy_ops;
 	const struct dw_mipi_dsi_host_ops *host_ops;