[PATCH v3 2/7] drm: exynos: dsi: Use drm panel_bridge API

Jagan Teki jagan at amarulasolutions.com
Mon Dec 13 09:14:55 UTC 2021


Hi Andrzej,

On Mon, Dec 13, 2021 at 2:39 PM Andrzej Hajda <andrzej.hajda at intel.com> wrote:
>
>
> On 12.12.2021 19:14, Jagan Teki wrote:
> > Replace the manual panel handling code by a drm panel_bridge via
> > devm_drm_of_get_bridge().
> >
> > Adding panel_bridge handling,
> >
> > - Drops drm_connector and related operations as drm_bridge_attach
> >    creates connector during attachment.
> >
> > - Drops panel pointer and iterate the bridge, so-that it can operate
> >    the normal bridge and panel_bridge in constitutive callbacks.
> >
> > This simplifies the driver and allows all components in the display
> > pipeline to be treated as bridges.
> >
> > Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> > ---
> > Changes for v3:
> > - fix port number
> > - add print for attached device
> > Changes for v2:
> > - new patch
> >
> >   drivers/gpu/drm/exynos/exynos_drm_dsi.c | 165 ++++--------------------
> >   1 file changed, 26 insertions(+), 139 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > index 0bb44e476633..d1039628b6f2 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> > @@ -221,6 +221,11 @@ enum exynos_dsi_transfer_type {
> >       EXYNOS_DSI_RX,
> >   };
> >
> > +enum {
> > +     DSI_PORT_IN,
> > +     DSI_PORT_OUT
> > +};
> > +
> >   struct exynos_dsi_transfer {
> >       struct list_head list;
> >       struct completion completed;
> > @@ -254,8 +259,6 @@ struct exynos_dsi_driver_data {
> >   struct exynos_dsi {
> >       struct drm_encoder encoder;
> >       struct mipi_dsi_host dsi_host;
> > -     struct drm_connector connector;
> > -     struct drm_panel *panel;
> >       struct list_head bridge_chain;
> >       struct drm_bridge *out_bridge;
> >       struct device *dev;
> > @@ -285,7 +288,6 @@ struct exynos_dsi {
> >   };
> >
> >   #define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)
> > -#define connector_to_dsi(c) container_of(c, struct exynos_dsi, connector)
> >
> >   static inline struct exynos_dsi *encoder_to_dsi(struct drm_encoder *e)
> >   {
> > @@ -1391,42 +1393,21 @@ static void exynos_dsi_enable(struct drm_encoder *encoder)
> >
> >       dsi->state |= DSIM_STATE_ENABLED;
> >
> > -     if (dsi->panel) {
> > -             ret = drm_panel_prepare(dsi->panel);
> > -             if (ret < 0)
> > -                     goto err_put_sync;
> > -     } else {
> > -             list_for_each_entry_reverse(iter, &dsi->bridge_chain,
> > -                                         chain_node) {
> > -                     if (iter->funcs->pre_enable)
> > -                             iter->funcs->pre_enable(iter);
> > -             }
> > +     list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
> > +             if (iter->funcs->pre_enable)
> > +                     iter->funcs->pre_enable(iter);
> >       }
> >
> >       exynos_dsi_set_display_mode(dsi);
> >       exynos_dsi_set_display_enable(dsi, true);
> >
> > -     if (dsi->panel) {
> > -             ret = drm_panel_enable(dsi->panel);
> > -             if (ret < 0)
> > -                     goto err_display_disable;
> > -     } else {
> > -             list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
> > -                     if (iter->funcs->enable)
> > -                             iter->funcs->enable(iter);
> > -             }
> > +     list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
> > +             if (iter->funcs->enable)
> > +                     iter->funcs->enable(iter);
> >       }
> >
> >       dsi->state |= DSIM_STATE_VIDOUT_AVAILABLE;
> >       return;
> > -
> > -err_display_disable:
> > -     exynos_dsi_set_display_enable(dsi, false);
> > -     drm_panel_unprepare(dsi->panel);
> > -
> > -err_put_sync:
> > -     dsi->state &= ~DSIM_STATE_ENABLED;
> > -     pm_runtime_put(dsi->dev);
> >   }
> >
> >   static void exynos_dsi_disable(struct drm_encoder *encoder)
> > @@ -1439,17 +1420,12 @@ static void exynos_dsi_disable(struct drm_encoder *encoder)
> >
> >       dsi->state &= ~DSIM_STATE_VIDOUT_AVAILABLE;
> >
> > -     if (dsi->panel)
> > -             drm_panel_disable(dsi->panel);
> > -
> >       list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
> >               if (iter->funcs->disable)
> >                       iter->funcs->disable(iter);
> >       }
> >
> >       exynos_dsi_set_display_enable(dsi, false);
> > -     if (dsi->panel)
> > -             drm_panel_unprepare(dsi->panel);
> >
> >       list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
> >               if (iter->funcs->post_disable)
> > @@ -1460,70 +1436,6 @@ static void exynos_dsi_disable(struct drm_encoder *encoder)
> >       pm_runtime_put_sync(dsi->dev);
> >   }
> >
> > -static enum drm_connector_status
> > -exynos_dsi_detect(struct drm_connector *connector, bool force)
> > -{
> > -     return connector->status;
> > -}
> > -
> > -static void exynos_dsi_connector_destroy(struct drm_connector *connector)
> > -{
> > -     drm_connector_unregister(connector);
> > -     drm_connector_cleanup(connector);
> > -     connector->dev = NULL;
> > -}
> > -
> > -static const struct drm_connector_funcs exynos_dsi_connector_funcs = {
> > -     .detect = exynos_dsi_detect,
> > -     .fill_modes = drm_helper_probe_single_connector_modes,
> > -     .destroy = exynos_dsi_connector_destroy,
> > -     .reset = drm_atomic_helper_connector_reset,
> > -     .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > -     .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > -};
> > -
> > -static int exynos_dsi_get_modes(struct drm_connector *connector)
> > -{
> > -     struct exynos_dsi *dsi = connector_to_dsi(connector);
> > -
> > -     if (dsi->panel)
> > -             return drm_panel_get_modes(dsi->panel, connector);
> > -
> > -     return 0;
> > -}
> > -
> > -static const struct drm_connector_helper_funcs exynos_dsi_connector_helper_funcs = {
> > -     .get_modes = exynos_dsi_get_modes,
> > -};
> > -
> > -static int exynos_dsi_create_connector(struct drm_encoder *encoder)
> > -{
> > -     struct exynos_dsi *dsi = encoder_to_dsi(encoder);
> > -     struct drm_connector *connector = &dsi->connector;
> > -     struct drm_device *drm = encoder->dev;
> > -     int ret;
> > -
> > -     connector->polled = DRM_CONNECTOR_POLL_HPD;
> > -
> > -     ret = drm_connector_init(drm, connector, &exynos_dsi_connector_funcs,
> > -                              DRM_MODE_CONNECTOR_DSI);
> > -     if (ret) {
> > -             DRM_DEV_ERROR(dsi->dev,
> > -                           "Failed to initialize connector with drm\n");
> > -             return ret;
> > -     }
> > -
> > -     connector->status = connector_status_disconnected;
> > -     drm_connector_helper_add(connector, &exynos_dsi_connector_helper_funcs);
> > -     drm_connector_attach_encoder(connector, encoder);
> > -     if (!drm->registered)
> > -             return 0;
> > -
> > -     connector->funcs->reset(connector);
> > -     drm_connector_register(connector);
> > -     return 0;
> > -}
> > -
> >   static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {
> >       .enable = exynos_dsi_enable,
> >       .disable = exynos_dsi_disable,
> > @@ -1537,31 +1449,20 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
> >       struct exynos_dsi *dsi = host_to_dsi(host);
> >       struct drm_encoder *encoder = &dsi->encoder;
> >       struct drm_device *drm = encoder->dev;
> > -     struct drm_bridge *out_bridge;
> > -
> > -     out_bridge  = of_drm_find_bridge(device->dev.of_node);
> > -     if (out_bridge) {
> > -             drm_bridge_attach(encoder, out_bridge, NULL, 0);
> > -             dsi->out_bridge = out_bridge;
> > -             list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
> > -     } else {
> > -             int ret = exynos_dsi_create_connector(encoder);
> > -
> > -             if (ret) {
> > -                     DRM_DEV_ERROR(dsi->dev,
> > -                                   "failed to create connector ret = %d\n",
> > -                                   ret);
> > -                     drm_encoder_cleanup(encoder);
> > -                     return ret;
> > -             }
> > +     int ret;
> >
> > -             dsi->panel = of_drm_find_panel(device->dev.of_node);
> > -             if (IS_ERR(dsi->panel))
> > -                     dsi->panel = NULL;
> > -             else
> > -                     dsi->connector.status = connector_status_connected;
> > +     dsi->out_bridge = devm_drm_of_get_bridge(dsi->dev, dsi->dev->of_node, DSI_PORT_OUT, 0);
> > +     if (IS_ERR(dsi->out_bridge)) {
> > +             ret = PTR_ERR(dsi->out_bridge);
> > +             DRM_DEV_ERROR(dsi->dev, "failed to find the bridge: %d\n", ret);
> > +             return ret;
> >       }
> >
> > +     DRM_DEV_INFO(dsi->dev, "Attached %s device\n", device->name);
> > +
> > +     drm_bridge_attach(encoder, dsi->out_bridge, NULL, 0);
> > +     list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
> > +
> >       /*
> >        * This is a temporary solution and should be made by more generic way.
> >        *
> > @@ -1569,7 +1470,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
> >        * TE interrupt handler.
> >        */
> >       if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO)) {
> > -             int ret = exynos_dsi_register_te_irq(dsi, &device->dev);
> > +             ret = exynos_dsi_register_te_irq(dsi, &device->dev);
> >               if (ret)
> >                       return ret;
> >       }
> > @@ -1596,18 +1497,9 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
> >       struct exynos_dsi *dsi = host_to_dsi(host);
> >       struct drm_device *drm = dsi->encoder.dev;
> >
> > -     if (dsi->panel) {
> > -             mutex_lock(&drm->mode_config.mutex);
> > -             exynos_dsi_disable(&dsi->encoder);
> > -             dsi->panel = NULL;
> > -             dsi->connector.status = connector_status_disconnected;
> > -             mutex_unlock(&drm->mode_config.mutex);
> > -     } else {
> > -             if (dsi->out_bridge->funcs->detach)
> > -                     dsi->out_bridge->funcs->detach(dsi->out_bridge);
> > -             dsi->out_bridge = NULL;
> > -             INIT_LIST_HEAD(&dsi->bridge_chain);
> > -     }
> > +     if (dsi->out_bridge->funcs->detach)
> > +             dsi->out_bridge->funcs->detach(dsi->out_bridge);
> > +     INIT_LIST_HEAD(&dsi->bridge_chain);
>
>
> This is fishy. Currently the only bridge used with exynos_dsi (tc358764)
> on detach callback unregisters/puts the connector it has created.

I have a patch to drop the existing connector and add panel_bridge for
tc358764. I believe this solve the connector stuff.

>
> With this code panel_bridge on detach will call drm_connector_cleanup,
> which will WARN about unregistered connector - ie it assumes detach
> should be called at least AFTER unregistration of exynos_drm device (???).

Same will sort out if downstream bridge has panel_bridge conversation i think.

>
> Since panel/bridge unbind in general case is not handled properly maybe
> it is not an issue :)

i.e what I belive.

Jagan.


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