[PATCH] drm/bridge: sii902x: add support for DRM_BRIDGE_ATTACH_NO_CONNECTOR

From: Neil Armstrong
Date: Thu Jan 13 2022 - 09:43:12 EST


This adds support for DRM_BRIDGE_ATTACH_NO_CONNECTOR by adding the
bridge get_edid() and detect() callbacks after refactoring the connector
get_modes() and connector_detect() callbacks.

In order to keep the bridge working, extra code in get_modes() has been
moved to more logical places.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/sii902x.c | 129 ++++++++++++++++++++++++-------
1 file changed, 99 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sii902x.c b/drivers/gpu/drm/bridge/sii902x.c
index 89558e581530..65549fbfdc87 100644
--- a/drivers/gpu/drm/bridge/sii902x.c
+++ b/drivers/gpu/drm/bridge/sii902x.c
@@ -166,10 +166,12 @@ struct sii902x {
struct i2c_client *i2c;
struct regmap *regmap;
struct drm_bridge bridge;
+ struct drm_bridge *next_bridge;
struct drm_connector connector;
struct gpio_desc *reset_gpio;
struct i2c_mux_core *i2cmux;
struct regulator_bulk_data supplies[2];
+ bool sink_is_hdmi;
/*
* Mutex protects audio and video functions from interfering
* each other, by keeping their i2c command sequences atomic.
@@ -245,10 +247,8 @@ static void sii902x_reset(struct sii902x *sii902x)
gpiod_set_value(sii902x->reset_gpio, 0);
}

-static enum drm_connector_status
-sii902x_connector_detect(struct drm_connector *connector, bool force)
+static enum drm_connector_status sii902x_detect(struct sii902x *sii902x)
{
- struct sii902x *sii902x = connector_to_sii902x(connector);
unsigned int status;

mutex_lock(&sii902x->mutex);
@@ -261,6 +261,14 @@ sii902x_connector_detect(struct drm_connector *connector, bool force)
connector_status_connected : connector_status_disconnected;
}

+static enum drm_connector_status
+sii902x_connector_detect(struct drm_connector *connector, bool force)
+{
+ struct sii902x *sii902x = connector_to_sii902x(connector);
+
+ return sii902x_detect(sii902x);
+}
+
static const struct drm_connector_funcs sii902x_connector_funcs = {
.detect = sii902x_connector_detect,
.fill_modes = drm_helper_probe_single_connector_modes,
@@ -270,42 +278,40 @@ static const struct drm_connector_funcs sii902x_connector_funcs = {
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

-static int sii902x_get_modes(struct drm_connector *connector)
+static struct edid *sii902x_get_edid(struct sii902x *sii902x,
+ struct drm_connector *connector)
{
- struct sii902x *sii902x = connector_to_sii902x(connector);
- u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
- u8 output_mode = SII902X_SYS_CTRL_OUTPUT_DVI;
struct edid *edid;
- int num = 0, ret;

mutex_lock(&sii902x->mutex);

edid = drm_get_edid(connector, sii902x->i2cmux->adapter[0]);
- drm_connector_update_edid_property(connector, edid);
if (edid) {
if (drm_detect_hdmi_monitor(edid))
- output_mode = SII902X_SYS_CTRL_OUTPUT_HDMI;
-
- num = drm_add_edid_modes(connector, edid);
- kfree(edid);
+ sii902x->sink_is_hdmi = true;
+ else
+ sii902x->sink_is_hdmi = false;
}

- ret = drm_display_info_set_bus_formats(&connector->display_info,
- &bus_format, 1);
- if (ret)
- goto error_out;
+ mutex_unlock(&sii902x->mutex);

- ret = regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
- SII902X_SYS_CTRL_OUTPUT_MODE, output_mode);
- if (ret)
- goto error_out;
+ return edid;
+}

- ret = num;
+static int sii902x_get_modes(struct drm_connector *connector)
+{
+ struct sii902x *sii902x = connector_to_sii902x(connector);
+ struct edid *edid;
+ int num = 0;

-error_out:
- mutex_unlock(&sii902x->mutex);
+ edid = sii902x_get_edid(sii902x, connector);
+ drm_connector_update_edid_property(connector, edid);
+ if (edid) {
+ num = drm_add_edid_modes(connector, edid);
+ kfree(edid);
+ }

- return ret;
+ return num;
}

static enum drm_mode_status sii902x_mode_valid(struct drm_connector *connector,
@@ -354,12 +360,16 @@ static void sii902x_bridge_mode_set(struct drm_bridge *bridge,
const struct drm_display_mode *adj)
{
struct sii902x *sii902x = bridge_to_sii902x(bridge);
+ u8 output_mode = SII902X_SYS_CTRL_OUTPUT_DVI;
struct regmap *regmap = sii902x->regmap;
u8 buf[HDMI_INFOFRAME_SIZE(AVI)];
struct hdmi_avi_infoframe frame;
u16 pixel_clock_10kHz = adj->clock / 10;
int ret;

+ if (sii902x->sink_is_hdmi)
+ output_mode = SII902X_SYS_CTRL_OUTPUT_HDMI;
+
buf[0] = pixel_clock_10kHz & 0xff;
buf[1] = pixel_clock_10kHz >> 8;
buf[2] = drm_mode_vrefresh(adj);
@@ -375,6 +385,11 @@ static void sii902x_bridge_mode_set(struct drm_bridge *bridge,

mutex_lock(&sii902x->mutex);

+ ret = regmap_update_bits(sii902x->regmap, SII902X_SYS_CTRL_DATA,
+ SII902X_SYS_CTRL_OUTPUT_MODE, output_mode);
+ if (ret)
+ goto out;
+
ret = regmap_bulk_write(regmap, SII902X_TPI_VIDEO_DATA, buf, 10);
if (ret)
goto out;
@@ -405,13 +420,13 @@ static int sii902x_bridge_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct sii902x *sii902x = bridge_to_sii902x(bridge);
+ u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
struct drm_device *drm = bridge->dev;
int ret;

- if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
- DRM_ERROR("Fix bridge driver to make connector optional!");
- return -EINVAL;
- }
+ if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
+ return drm_bridge_attach(bridge->encoder, sii902x->next_bridge,
+ bridge, flags);

drm_connector_helper_add(&sii902x->connector,
&sii902x_connector_helper_funcs);
@@ -433,16 +448,38 @@ static int sii902x_bridge_attach(struct drm_bridge *bridge,
else
sii902x->connector.polled = DRM_CONNECTOR_POLL_CONNECT;

+ ret = drm_display_info_set_bus_formats(&sii902x->connector.display_info,
+ &bus_format, 1);
+ if (ret)
+ return ret;
+
drm_connector_attach_encoder(&sii902x->connector, bridge->encoder);

return 0;
}

+static enum drm_connector_status sii902x_bridge_detect(struct drm_bridge *bridge)
+{
+ struct sii902x *sii902x = bridge_to_sii902x(bridge);
+
+ return sii902x_detect(sii902x);
+}
+
+static struct edid *sii902x_bridge_get_edid(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct sii902x *sii902x = bridge_to_sii902x(bridge);
+
+ return sii902x_get_edid(sii902x, connector);
+}
+
static const struct drm_bridge_funcs sii902x_bridge_funcs = {
.attach = sii902x_bridge_attach,
.mode_set = sii902x_bridge_mode_set,
.disable = sii902x_bridge_disable,
.enable = sii902x_bridge_enable,
+ .detect = sii902x_bridge_detect,
+ .get_edid = sii902x_bridge_get_edid,
};

static int sii902x_mute(struct sii902x *sii902x, bool mute)
@@ -829,8 +866,12 @@ static irqreturn_t sii902x_interrupt(int irq, void *data)

mutex_unlock(&sii902x->mutex);

- if ((status & SII902X_HOTPLUG_EVENT) && sii902x->bridge.dev)
+ if ((status & SII902X_HOTPLUG_EVENT) && sii902x->bridge.dev) {
drm_helper_hpd_irq_event(sii902x->bridge.dev);
+ drm_bridge_hpd_notify(&sii902x->bridge, (status & SII902X_PLUGGED_STATUS)
+ ? connector_status_connected
+ : connector_status_disconnected);
+ }

return IRQ_HANDLED;
}
@@ -1001,6 +1042,11 @@ static int sii902x_init(struct sii902x *sii902x)
sii902x->bridge.funcs = &sii902x_bridge_funcs;
sii902x->bridge.of_node = dev->of_node;
sii902x->bridge.timings = &default_sii902x_timings;
+ sii902x->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;
+
+ if (sii902x->i2c->irq > 0)
+ sii902x->bridge.ops |= DRM_BRIDGE_OP_HPD;
+
drm_bridge_add(&sii902x->bridge);

sii902x_audio_codec_init(sii902x, dev);
@@ -1022,6 +1068,7 @@ static int sii902x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
+ struct device_node *endpoint;
struct sii902x *sii902x;
int ret;

@@ -1049,6 +1096,28 @@ static int sii902x_probe(struct i2c_client *client,
return PTR_ERR(sii902x->reset_gpio);
}

+ endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
+ if (endpoint) {
+ struct device_node *remote = of_graph_get_remote_port_parent(endpoint);
+
+ of_node_put(endpoint);
+ if (!remote) {
+ dev_err(dev, "Endpoint in port@1 unconnected\n");
+ return -ENODEV;
+ }
+
+ if (!of_device_is_available(remote)) {
+ dev_err(dev, "port@1 remote device is disabled\n");
+ of_node_put(remote);
+ return -ENODEV;
+ }
+
+ sii902x->next_bridge = of_drm_find_bridge(remote);
+ of_node_put(remote);
+ if (!sii902x->next_bridge)
+ return -EPROBE_DEFER;
+ }
+
mutex_init(&sii902x->mutex);

sii902x->supplies[0].supply = "iovcc";
--
2.25.1