[PATCH v2 3/6] drm/sun4i: dsi: Add bridge support

Jagan Teki
2019-05-24T10:43:14Z

Some display panels would come up with a non-DSI output which
can have an option to connect DSI interface by means of bridge
converter.

This DSI to non-DSI bridge converter would require a bridge
driver that would communicate the DSI controller for bridge
functionalities.

So, add support for bridge functionalities in Allwinner DSI
controller.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 60 +++++++++++++++++++-------
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 +
2 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index ae2fe31b05b1..2b4b1355a88f 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -775,6 +775,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel))
drm_panel_prepare(dsi->panel);

+ if (!IS_ERR(dsi->bridge))
+ drm_bridge_pre_enable(dsi->bridge);
+
/*
* FIXME: This should be moved after the switch to HS mode.
*
@@ -790,6 +793,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel))
drm_panel_enable(dsi->panel);

+ if (!IS_ERR(dsi->bridge))
+ drm_bridge_enable(dsi->bridge);
+
sun6i_dsi_start(dsi, DSI_START_HSC);

udelay(1000);
@@ -806,6 +812,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel)) {
drm_panel_disable(dsi->panel);
drm_panel_unprepare(dsi->panel);
+ } else if (!IS_ERR(dsi->bridge)) {
+ drm_bridge_disable(dsi->bridge);
+ drm_bridge_post_disable(dsi->bridge);
}

phy_power_off(dsi->dphy);
@@ -969,11 +978,12 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,

dsi->device = device;
ret = drm_of_find_panel_or_bridge(host->dev->of_node, 0, 0,
- &dsi->panel, NULL);
+ &dsi->panel, &dsi->bridge);
if (ret)
return ret;

- dev_info(host->dev, "Attached device %s\n", device->name);
+ dev_info(host->dev, "Attached %s %s\n",
+ dsi->bridge ? "bridge" : "panel", device->name);

return 0;
}
@@ -983,7 +993,10 @@ static int sun6i_dsi_detach(struct mipi_dsi_host *host,
{
struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);

- dsi->panel = NULL;
+ if (dsi->panel)
+ dsi->panel = NULL;
+ else if (dsi->bridge)
+ dsi->bridge = NULL;
dsi->device = NULL;

return 0;
@@ -1055,8 +1068,10 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
struct sun4i_tcon *tcon0 = sun4i_get_tcon0(drm);
int ret;

- if (!dsi->panel)
+ if (!(dsi->panel || dsi->bridge)) {
+ dev_info(drm->dev, "No panel or bridge found... DSI output disabled\n");
return -EPROBE_DEFER;
+ }

dsi->drv = drv;

@@ -1078,19 +1093,29 @@ 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);
- if (ret) {
- dev_err(dsi->dev,
- "Couldn't initialise the DSI connector\n");
- goto err_cleanup_connector;
+ 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);
+ drm_panel_attach(dsi->panel, &dsi->connector);
}

- drm_connector_attach_encoder(&dsi->connector, &dsi->encoder);
- drm_panel_attach(dsi->panel, &dsi->connector);
+ if (dsi->bridge) {
+ ret = drm_bridge_attach(&dsi->encoder, dsi->bridge, NULL);
+ if (ret) {
+ dev_err(dsi->dev, "Couldn't attach the DSI bridge\n");
+ goto err_cleanup_connector;
+ }
+ }

return 0;

@@ -1104,7 +1129,10 @@ static void sun6i_dsi_unbind(struct device *dev, struct device *master,
{
struct sun6i_dsi *dsi = dev_get_drvdata(dev);

- drm_panel_detach(dsi->panel);
+ if (dsi->panel)
+ drm_panel_detach(dsi->panel);
+ else if (dsi->bridge->funcs->detach)
+ dsi->bridge->funcs->detach(dsi->bridge);
}

static const struct component_ops sun6i_dsi_ops = {
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
index c570f2b3868f..c76b71259d2e 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
@@ -32,6 +32,7 @@ struct sun6i_dsi {
struct sun4i_tcon *tcon;
struct mipi_dsi_device *device;
struct drm_panel *panel;
+ struct drm_bridge *bridge;
};

static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)
--
2.18.0.321.gffc6fa0e3