[PATCH] drm/sun4i: hdmi: add support for ddc-i2c-bus property

Mans Rullgard
2019-03-28T13:02:56Z

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>
---
Changed in v2:
- Return ERR_PTR(-ENODEV) instead of NULL when property is absent
---
drivers/gpu/drm/sun4i/sun4i_hdmi.h | 1 +
drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c | 40 ++++++++++++++++++++++++--
2 files changed, 38 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 416da5376701..a99523e9651f 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -216,7 +216,7 @@ 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);
if (!edid)
return 0;

@@ -232,6 +232,28 @@ 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 ERR_PTR(-ENODEV);
+
+ ddc = of_get_i2c_adapter_by_node(phandle);
+ of_node_put(phandle);
+ if (!ddc)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return ddc;
+}
+
static const struct drm_connector_helper_funcs sun4i_hdmi_connector_helper_funcs = {
.get_modes = sun4i_hdmi_get_modes,
};
@@ -579,6 +601,15 @@ 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)) {
+ ret = PTR_ERR(hdmi->ddc_i2c);
+ if (ret == -ENODEV)
+ hdmi->ddc_i2c = NULL;
+ else
+ goto err_del_i2c_adapter;
+ }
+
drm_encoder_helper_add(&hdmi->encoder,
&sun4i_hdmi_helper_funcs);
ret = drm_encoder_init(drm,
@@ -588,14 +619,14 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
NULL);
if (ret) {
dev_err(dev, "Couldn't initialise the HDMI encoder\n");
- goto err_del_i2c_adapter;
+ goto err_put_ddc_i2c;
}

hdmi->encoder.possible_crtcs = drm_of_find_possible_crtcs(drm,
dev->of_node);
if (!hdmi->encoder.possible_crtcs) {
ret = -EPROBE_DEFER;
- goto err_del_i2c_adapter;
+ goto err_put_ddc_i2c;
}

#ifdef CONFIG_DRM_SUN4I_HDMI_CEC
@@ -634,6 +665,8 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
err_cleanup_connector:
cec_delete_adapter(hdmi->cec_adap);
drm_encoder_cleanup(&hdmi->encoder);
+err_put_ddc_i2c:
+ i2c_put_adapter(hdmi->ddc_i2c);
err_del_i2c_adapter:
i2c_del_adapter(hdmi->i2c);
err_disable_mod_clk:
@@ -654,6 +687,7 @@ static void sun4i_hdmi_unbind(struct device *dev, struct device *master,
drm_connector_cleanup(&hdmi->connector);
drm_encoder_cleanup(&hdmi->encoder);
i2c_del_adapter(hdmi->i2c);
+ i2c_put_adapter(hdmi->ddc_i2c);
clk_disable_unprepare(hdmi->mod_clk);
clk_disable_unprepare(hdmi->bus_clk);
}
--
2.21.0