Maxime Ripard maxime.ripard@bootlin.com writes:
Hi!
On Mon, Mar 11, 2019 at 01:47:13PM +0000, Mans Rullgard wrote:
Sometimes it is desirabled to use a separate i2c controller for ddc access. This adds support for the ddc-i2c-bus property of the hdmi-connector node, using the specified controller if provided.
Signed-off-by: Mans Rullgard mans@mansr.com
drivers/gpu/drm/sun4i/sun4i_hdmi.h | 1 + drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 37 +++++++++++++++++++++++--- 2 files changed, 35 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi.h b/drivers/gpu/drm/sun4i/sun4i_hdmi.h index b685ee11623d..b08c4453d47c 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi.h +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi.h @@ -269,6 +269,7 @@ struct sun4i_hdmi { struct clk *tmds_clk;
struct i2c_adapter *i2c;
struct i2c_adapter *ddc_i2c;
/* Regmap fields for I2C adapter */ struct regmap_field *field_ddc_en;
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c index 061d2e0d9011..5b2fac79f5d6 100644 --- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c @@ -212,7 +212,7 @@ static int sun4i_hdmi_get_modes(struct drm_connector *connector) struct edid *edid; int ret;
- edid = drm_get_edid(connector, hdmi->i2c);
- edid = drm_get_edid(connector, hdmi->ddc_i2c ?: hdmi->i2c);
You can't test whether ddc_i2c is NULL or not...
if (!edid) return 0;
@@ -228,6 +228,28 @@ static int sun4i_hdmi_get_modes(struct drm_connector *connector) return ret; }
+static struct i2c_adapter *sun4i_hdmi_get_ddc(struct device *dev) +{
- struct device_node *phandle, *remote;
- struct i2c_adapter *ddc;
- remote = of_graph_get_remote_node(dev->of_node, 1, -1);
- if (!remote)
return ERR_PTR(-EINVAL);- phandle = of_parse_phandle(remote, "ddc-i2c-bus", 0);
- of_node_put(remote);
- if (!phandle)
return NULL;- ddc = of_get_i2c_adapter_by_node(phandle);
- of_node_put(phandle);
- if (!ddc)
return ERR_PTR(-EPROBE_DEFER);- return ddc;
... Since even in (most) error cases you're returning a !NULL pointer.
+}
static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = { .get_modes = sun4i_hdmi_get_modes, }; @@ -575,6 +597,12 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master, goto err_disable_mod_clk; }
- hdmi->ddc_i2c = sun4i_hdmi_get_ddc(dev);
- if (IS_ERR(hdmi->ddc_i2c)) {
... which is checked here.
The property is optional, so the idea was to return null in that case and use the built-in controller. If the property exists but some error occurs, we want to abort rather than proceed with the fallback which almost certainly won't work.
Maybe I got something wrong in that logic.