[PATCH v4 1/6] drm/bridge: dw-hdmi: allow forcing vendor phy-type

[Heiko Stuebner]

In some IP implementations the reading of the phy-type may be broken.
One example are the Rockchip rk3228 and rk3328 socs that use a separate
vendor-type phy from Innosilicon but still report the HDMI20_TX type.

So allow the glue driver to force the vendor-phy for these cases.
In the future it may be necessary to allow forcing other types, but
for now we'll keep it simply to the case actually seen in the wild.

changes in v3:
- only allow forcing vendor type, as suggested by Laurent

Signed-off-by: Heiko Stuebner <heiko at sntech.de>
Tested-by: Robin Murphy <robin.murphy at arm.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 +++-
 include/drm/bridge/dw_hdmi.h              | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 5971976284bf..ac37c50d6c4b 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -2205,7 +2205,9 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
 	unsigned int i;
 	u8 phy_type;
 
-	phy_type = hdmi_readb(hdmi, HDMI_CONFIG2_ID);
+	phy_type = hdmi->plat_data->phy_force_vendor ?
+				DW_HDMI_PHY_VENDOR_PHY :
+				hdmi_readb(hdmi, HDMI_CONFIG2_ID);
 
 	if (phy_type == DW_HDMI_PHY_VENDOR_PHY) {
 		/* Vendor PHYs require support from the glue layer. */
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index ccb5aa8468e0..6ef3236bb6dd 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -133,6 +133,7 @@ struct dw_hdmi_plat_data {
 	const struct dw_hdmi_phy_ops *phy_ops;
 	const char *phy_name;
 	void *phy_data;
+	bool phy_force_vendor;
 
 	/* Synopsys PHY support */
 	const struct dw_hdmi_mpll_config *mpll_cfg;
-- 
2.17.0