[RFC PATCH 4/4] drm/rockchip: rgb: Add dphy connection to rgb output

[Michael Trimarchi]

Dispite the commit 1f0f015151727, the rgb output has an option
to allow to sent the output pin using the dsi/lvds/ttl logic.
The only way to do and stay on the same design is let the
rockchip_rgb block to grab the handle if it is present and
enable it. The present of this handle depends on dts configuration

I have a full working example with an hardware with mixed lines
on direct logic and using the phy, with the follow dts example:

panel: panel {
        compatible = "panel-dpi";
        ...
        panel-timing {
                clock-frequency = <30000000>;
                ...
        };

        port {
                panel_rgb_in: endpoint {
                        remote-endpoint = <&vopb_out_rgb>;
                };
        };
};

&vopb_out {
        vopb_out_rgb: endpoint@2 {
                reg = <2>;
                remote-endpoint = <&panel_rgb_in>;
        };
};

&vopb {
        status = "okay";
        pinctrl-names = "default", "sleep";
        pinctrl-0 = <&lcdc_rgb_pins>;
        pinctrl-1 = <&lcdc_sleep_pins>;

        phys = <&dsi_dphy>;
        phy-names = "dphy";
};

Signed-off-by: Michael Trimarchi <mich...@amarulasolutions.com>
---
 drivers/gpu/drm/rockchip/rockchip_rgb.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_rgb.c 
b/drivers/gpu/drm/rockchip/rockchip_rgb.c
index 75eb7cca3d82..c725774a0f40 100644
--- a/drivers/gpu/drm/rockchip/rockchip_rgb.c
+++ b/drivers/gpu/drm/rockchip/rockchip_rgb.c
@@ -8,6 +8,7 @@
 #include <linux/component.h>
 #include <linux/media-bus-format.h>
 #include <linux/of_graph.h>
+#include <linux/phy/phy.h>
 
 #include <drm/display/drm_dp_helper.h>
 #include <drm/drm_atomic_helper.h>
@@ -30,6 +31,7 @@ struct rockchip_rgb {
        struct drm_bridge *bridge;
        struct drm_encoder encoder;
        struct drm_connector connector;
+       struct phy *dphy;
        int output_mode;
 };
 
@@ -168,6 +170,22 @@ struct rockchip_rgb *rockchip_rgb_init(struct device *dev,
                goto err_free_connector;
        }
 
+       /* PHY */
+       rgb->dphy = devm_phy_get(dev, "dphy");
+       if (!IS_ERR(rgb->dphy)) {
+               ret = phy_init(rgb->dphy);
+               if (ret)
+                       return ERR_PTR(ret);
+
+               ret = phy_set_mode(rgb->dphy, PHY_MODE_TTL);
+               if (ret)
+                       return ERR_PTR(ret);
+
+               ret = phy_power_on(rgb->dphy);
+               if (ret)
+                       return ERR_PTR(ret);
+       }
+
        return rgb;
 
 err_free_connector:
-- 
2.34.1