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path: root/drivers/gpu/drm
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Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/bridge/ti-tfp410.c77
1 files changed, 74 insertions, 3 deletions
diff --git a/drivers/gpu/drm/bridge/ti-tfp410.c b/drivers/gpu/drm/bridge/ti-tfp410.c
index b0213d573434..285be4a0f4bd 100644
--- a/drivers/gpu/drm/bridge/ti-tfp410.c
+++ b/drivers/gpu/drm/bridge/ti-tfp410.c
@@ -34,6 +34,8 @@ struct tfp410 {
struct delayed_work hpd_work;
struct gpio_desc *powerdown;
+ struct drm_bridge_timings timings;
+
struct device *dev;
};
@@ -180,6 +182,70 @@ static irqreturn_t tfp410_hpd_irq_thread(int irq, void *arg)
return IRQ_HANDLED;
}
+static const struct drm_bridge_timings tfp410_default_timings = {
+ .input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
+ | DRM_BUS_FLAG_DE_HIGH,
+ .setup_time_ps = 1200,
+ .hold_time_ps = 1300,
+};
+
+static int tfp410_parse_timings(struct tfp410 *dvi, bool i2c)
+{
+ struct drm_bridge_timings *timings = &dvi->timings;
+ struct device_node *ep;
+ u32 pclk_sample = 0;
+ s32 deskew = 0;
+
+ /* Start with defaults. */
+ *timings = tfp410_default_timings;
+
+ if (i2c)
+ /*
+ * In I2C mode timings are configured through the I2C interface.
+ * As the driver doesn't support I2C configuration yet, we just
+ * go with the defaults (BSEL=1, DSEL=1, DKEN=0, EDGE=1).
+ */
+ return 0;
+
+ /*
+ * In non-I2C mode, timings are configured through the BSEL, DSEL, DKEN
+ * and EDGE pins. They are specified in DT through endpoint properties
+ * and vendor-specific properties.
+ */
+ ep = of_graph_get_endpoint_by_regs(dvi->dev->of_node, 0, 0);
+ if (!ep)
+ return -EINVAL;
+
+ /* Get the sampling edge from the endpoint. */
+ of_property_read_u32(ep, "pclk-sample", &pclk_sample);
+ of_node_put(ep);
+
+ timings->input_bus_flags = DRM_BUS_FLAG_DE_HIGH;
+
+ switch (pclk_sample) {
+ case 0:
+ timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE
+ | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE;
+ break;
+ case 1:
+ timings->input_bus_flags |= DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE
+ | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Get the setup and hold time from vendor-specific properties. */
+ of_property_read_u32(dvi->dev->of_node, "ti,deskew", (u32 *)&deskew);
+ if (deskew < -4 || deskew > 3)
+ return -EINVAL;
+
+ timings->setup_time_ps = min(0, 1200 - 350 * deskew);
+ timings->hold_time_ps = min(0, 1300 + 350 * deskew);
+
+ return 0;
+}
+
static int tfp410_get_connector_properties(struct tfp410 *dvi)
{
struct device_node *connector_node, *ddc_phandle;
@@ -223,7 +289,7 @@ fail:
return ret;
}
-static int tfp410_init(struct device *dev)
+static int tfp410_init(struct device *dev, bool i2c)
{
struct tfp410 *dvi;
int ret;
@@ -240,8 +306,13 @@ static int tfp410_init(struct device *dev)
dvi->bridge.funcs = &tfp410_bridge_funcs;
dvi->bridge.of_node = dev->of_node;
+ dvi->bridge.timings = &dvi->timings;
dvi->dev = dev;
+ ret = tfp410_parse_timings(dvi, i2c);
+ if (ret)
+ goto fail;
+
ret = tfp410_get_connector_properties(dvi);
if (ret)
goto fail;
@@ -294,7 +365,7 @@ static int tfp410_fini(struct device *dev)
static int tfp410_probe(struct platform_device *pdev)
{
- return tfp410_init(&pdev->dev);
+ return tfp410_init(&pdev->dev, false);
}
static int tfp410_remove(struct platform_device *pdev)
@@ -331,7 +402,7 @@ static int tfp410_i2c_probe(struct i2c_client *client,
return -ENXIO;
}
- return tfp410_init(&client->dev);
+ return tfp410_init(&client->dev, true);
}
static int tfp410_i2c_remove(struct i2c_client *client)