Support boards with a passive RGB to VGA bridge which require a low active data-enable polarity.
Signed-off-by: Stefan Agner stefan@agner.ch --- Alternatively a new dt binding could be introduced for dumb VGA bridges requiring low active data enable... However, also other polarities might need a specific polarity, hence this generic approach might be better.
drivers/gpu/drm/bridge/dumb-vga-dac.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/bridge/dumb-vga-dac.c b/drivers/gpu/drm/bridge/dumb-vga-dac.c index 7a5c24967115..2b8c3d629f2f 100644 --- a/drivers/gpu/drm/bridge/dumb-vga-dac.c +++ b/drivers/gpu/drm/bridge/dumb-vga-dac.c @@ -179,6 +179,7 @@ static struct i2c_adapter *dumb_vga_retrieve_ddc(struct device *dev) static int dumb_vga_probe(struct platform_device *pdev) { struct dumb_vga *vga; + u32 de;
vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL); if (!vga) @@ -194,6 +195,23 @@ static int dumb_vga_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "No vdd regulator found: %d\n", ret); }
+ vga->bridge.funcs = &dumb_vga_bridge_funcs; + vga->bridge.of_node = pdev->dev.of_node; + vga->bridge.timings = of_device_get_match_data(&pdev->dev); + + if (!vga->bridge.timings && + !of_property_read_u32(pdev->dev.of_node, "de-active", &de)) { + struct drm_bridge_timings *timings; + + timings = devm_kzalloc(&pdev->dev, sizeof(*timings), GFP_KERNEL); + if (!timings) + return -ENOMEM; + + timings->bus_flags = de ? DRM_BUS_FLAG_DE_HIGH : + DRM_BUS_FLAG_DE_LOW; + vga->bridge.timings = timings; + } + vga->ddc = dumb_vga_retrieve_ddc(&pdev->dev); if (IS_ERR(vga->ddc)) { if (PTR_ERR(vga->ddc) == -ENODEV) { @@ -205,10 +223,6 @@ static int dumb_vga_probe(struct platform_device *pdev) } }
- vga->bridge.funcs = &dumb_vga_bridge_funcs; - vga->bridge.of_node = pdev->dev.of_node; - vga->bridge.timings = of_device_get_match_data(&pdev->dev); - drm_bridge_add(&vga->bridge);
return 0;