On 22/11/2021 07:52, Jagan Teki wrote:
> Some display panels would come up with a non-DSI output, those
> can have an option to connect the DSI host by means of interface
> bridge converter.
>
> This DSI to non-DSI interface bridge converter would requires
> DSI Host to handle drm bridge functionalities in order to DSI
> Host to Interface bridge.
>
> This patch convert the existing to a drm bridge driver with a
> built-in encoder support for compatibility with existing
> component drivers.
>
> Signed-off-by: Jagan Teki <ja...@amarulasolutions.com>
> ---
> Changes for v5:
> - add atomic APIs
> - find host and device variant DSI devices.
> Changes for v4, v3:
> - none
>
> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 112 ++++++++++++++++++++-----
> drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 7 ++
> 2 files changed, 96 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> index 43d9c9e5198d..a6a272b55f77 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> @@ -21,6 +21,7 @@
>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
> #include <drm/drm_panel.h>
> #include <drm/drm_print.h>
> #include <drm/drm_probe_helper.h>
> @@ -713,10 +714,11 @@ static int sun6i_dsi_start(struct sun6i_dsi *dsi,
> return 0;
> }
>
> -static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
> +static void sun6i_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
> + struct drm_bridge_state
> *old_bridge_state)
> {
> - struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
> - struct sun6i_dsi *dsi = encoder_to_sun6i_dsi(encoder);
> + struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
> + struct drm_display_mode *mode =
> &bridge->encoder->crtc->state->adjusted_mode;
> struct mipi_dsi_device *device = dsi->device;
> union phy_configure_opts opts = { };
> struct phy_configure_opts_mipi_dphy *cfg = &opts.mipi_dphy;
> @@ -772,6 +774,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder
> *encoder)
> if (dsi->panel)
> drm_panel_prepare(dsi->panel);
>
> + if (dsi->next_bridge)
> + dsi->next_bridge->funcs->atomic_pre_enable(dsi->next_bridge,
> old_bridge_state);
> +
> /*
> * FIXME: This should be moved after the switch to HS mode.
> *
> @@ -787,6 +792,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder
> *encoder)
> if (dsi->panel)
> drm_panel_enable(dsi->panel);
>
> + if (dsi->next_bridge)
> + dsi->next_bridge->funcs->atomic_enable(dsi->next_bridge,
> old_bridge_state);
> +
No need to call the next bridge atomic pre_enable/enable/disable/post_disable
since they will
be called automatically on the bridge chain.
> sun6i_dsi_start(dsi, DSI_START_HSC);
>
> udelay(1000);
> @@ -794,15 +802,19 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder
> *encoder)
> sun6i_dsi_start(dsi, DSI_START_HSD);
> }
>
> -static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
> +static void sun6i_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
> + struct drm_bridge_state
> *old_bridge_state)
> {
> - struct sun6i_dsi *dsi = encoder_to_sun6i_dsi(encoder);
> + struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
>
> DRM_DEBUG_DRIVER("Disabling DSI output\n");
>
> if (dsi->panel) {
> drm_panel_disable(dsi->panel);
> drm_panel_unprepare(dsi->panel);
> + } else if (dsi->next_bridge) {
> + dsi->next_bridge->funcs->atomic_disable(dsi->next_bridge,
> old_bridge_state);
> + dsi->next_bridge->funcs->atomic_post_disable(dsi->next_bridge,
> old_bridge_state);
Ditto
> }
>
> phy_power_off(dsi->dphy);
> @@ -842,9 +854,25 @@ static const struct drm_connector_funcs
> sun6i_dsi_connector_funcs = {
> .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> };
>
> -static const struct drm_encoder_helper_funcs sun6i_dsi_enc_helper_funcs = {
> - .disable = sun6i_dsi_encoder_disable,
> - .enable = sun6i_dsi_encoder_enable,
> +static int sun6i_dsi_bridge_attach(struct drm_bridge *bridge,
> + enum drm_bridge_attach_flags flags)
> +{
> + struct sun6i_dsi *dsi = bridge_to_sun6i_dsi(bridge);
> +
> + if (dsi->next_bridge)
> + return drm_bridge_attach(bridge->encoder, dsi->next_bridge,
> + NULL, 0);
> +
> + return 0;
> +}
> +
> +static const struct drm_bridge_funcs sun6i_dsi_bridge_funcs = {
> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> + .atomic_reset = drm_atomic_helper_bridge_reset,
> + .atomic_enable = sun6i_dsi_bridge_atomic_enable,
> + .atomic_disable = sun6i_dsi_bridge_atomic_disable,
> + .attach = sun6i_dsi_bridge_attach,
> };
>
> static u32 sun6i_dsi_dcs_build_pkt_hdr(struct sun6i_dsi *dsi,
> @@ -966,8 +994,6 @@ static int sun6i_dsi_bind(struct device *dev, struct
> device *master,
> struct sun6i_dsi *dsi = dev_get_drvdata(dev);
> int ret;
>
> - drm_encoder_helper_add(&dsi->encoder,
> - &sun6i_dsi_enc_helper_funcs);
> ret = drm_simple_encoder_init(drm, &dsi->encoder,
> DRM_MODE_ENCODER_DSI);
> if (ret) {
> @@ -976,18 +1002,26 @@ static int sun6i_dsi_bind(struct device *dev, struct
> device *master,
> }
> dsi->encoder.possible_crtcs = BIT(0);
>
> - drm_connector_helper_add(&dsi->connector,
> - &sun6i_dsi_connector_helper_funcs);
> - ret = drm_connector_init(drm, &dsi->connector,
> - &sun6i_dsi_connector_funcs,
> - DRM_MODE_CONNECTOR_DSI);
> + ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> if (ret) {
> - dev_err(dsi->dev,
> - "Couldn't initialise the DSI connector\n");
> + dev_err(dsi->dev, "Couldn't attach drm bridge\n");
> goto err_cleanup_connector;
> }
>
> - drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);
> + if (dsi->panel) {
> + drm_connector_helper_add(&dsi->connector,
> + &sun6i_dsi_connector_helper_funcs);
> + ret = drm_connector_init(drm, &dsi->connector,
> + &sun6i_dsi_connector_funcs,
> + DRM_MODE_CONNECTOR_DSI);
> + if (ret) {
> + dev_err(dsi->dev,
> + "Couldn't initialise the DSI connector\n");
> + goto err_cleanup_connector;
> + }
> +
> + drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);
> + }
>
> return 0;
>
> @@ -1013,16 +1047,46 @@ static int sun6i_dsi_attach(struct mipi_dsi_host
> *host,
> struct mipi_dsi_device *device)
> {
> struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
> - struct drm_panel *panel = of_drm_find_panel(device->dev.of_node);
> + struct device_node *remote = device->dev.of_node;
> int ret;
>
> - if (IS_ERR(panel))
> - return PTR_ERR(panel);
> + if (!of_device_is_available(remote)) {
> + /**
> + * I2C interfaced DSI bridges will register DSI host on the
> + * bridge drivers instead of conventional device.
> + *
> + * Those are probed via host of_node instead of device of_node.
> + */
> + remote = of_graph_get_remote_node(host->dev->of_node, 0, 0);
> + if (!remote)
> + return -ENODEV;
> + }
> +
> + dsi->panel = of_drm_find_panel(remote);
> + if (IS_ERR(dsi->panel)) {
> + dsi->panel = NULL;
> +
> + dsi->next_bridge = of_drm_find_bridge(remote);
> + if (IS_ERR(dsi->next_bridge)) {
> + dev_err(dsi->dev, "failed to find bridge\n");
> + return PTR_ERR(dsi->next_bridge);
> + }
> + } else {
> + dsi->next_bridge = NULL;
> + }
> +
> + of_node_put(remote);
>
> - dsi->panel = panel;
> dsi->device = device;
>
> - dev_info(host->dev, "Attached device %s\n", device->name);
> + dev_info(host->dev, "Attached %s %s\n",
> + device->name, dsi->panel ? "panel" : "bridge");
> +
> + dsi->bridge.funcs = &sun6i_dsi_bridge_funcs;
> + dsi->bridge.of_node = dsi->dev->of_node;
> + dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> +
> + drm_bridge_add(&dsi->bridge);
>
> ret = component_add(dsi->dev, &sun6i_dsi_ops);
> if (ret) {
> @@ -1040,9 +1104,11 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host,
> struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
>
> dsi->panel = NULL;
> + dsi->next_bridge = NULL;
> dsi->device = NULL;
>
> component_del(dsi->dev, &sun6i_dsi_ops);
> + drm_bridge_remove(&dsi->bridge);
>
> return 0;
> }
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> index 61e88ea6044d..d269304691c9 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
> @@ -16,6 +16,7 @@
> #define SUN6I_DSI_TCON_DIV 4
>
> struct sun6i_dsi {
> + struct drm_bridge bridge;
> struct drm_connector connector;
> struct drm_encoder encoder;
> struct mipi_dsi_host host;
> @@ -30,6 +31,7 @@ struct sun6i_dsi {
> struct device *dev;
> struct mipi_dsi_device *device;
> struct drm_panel *panel;
> + struct drm_bridge *next_bridge;
> };
>
> static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)
> @@ -37,6 +39,11 @@ static inline struct sun6i_dsi *host_to_sun6i_dsi(struct
> mipi_dsi_host *host)
> return container_of(host, struct sun6i_dsi, host);
> };
>
> +static inline struct sun6i_dsi *bridge_to_sun6i_dsi(struct drm_bridge
> *bridge)
> +{
> + return container_of(bridge, struct sun6i_dsi, bridge);
> +}
> +
> static inline struct sun6i_dsi *connector_to_sun6i_dsi(struct drm_connector
> *connector)
> {
> return container_of(connector, struct sun6i_dsi, connector);
>
