drm/sun4i: dsi: Get the mod clock for A31

As per the user manual, look like mod clock is not mandatory
for all Allwinner MIPI DSI controllers, it is connected to
CLK_DSI_SCLK for A31 and not available in A64.

So, add compatible check for A31 and get mod clock accordingly.

Tested-by: Merlijn Wajer <merlijn@wizzup.org>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20191222132229.30276-4-jagan@amarulasolutions.com

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 4e8f634..9bb3222 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -1120,10 +1120,13 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
                return PTR_ERR(dsi->reset);
        }
 
-       dsi->mod_clk = devm_clk_get(dev, "mod");
-       if (IS_ERR(dsi->mod_clk)) {
-               dev_err(dev, "Couldn't get the DSI mod clock\n");
-               return PTR_ERR(dsi->mod_clk);
+       if (of_device_is_compatible(dev->of_node,
+                                   "allwinner,sun6i-a31-mipi-dsi")) {
+               dsi->mod_clk = devm_clk_get(dev, "mod");
+               if (IS_ERR(dsi->mod_clk)) {
+                       dev_err(dev, "Couldn't get the DSI mod clock\n");
+                       return PTR_ERR(dsi->mod_clk);
+               }
        }
 
        /*