drm/tegra: output: Make ->setup_clock() optional

In order to transition output drivers to using the struct tegra_output
as a helper rather than midlayer, make this callback optional. Instead
drivers should implement the equivalent as part of ->mode_fixup(). For
the conversion to atomic modesetting a new callback ->atomic_check()
should be implemented that updates the display controller's state with
the corresponding parent clock, rate and shift clock divider.

Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index d511730..e35e107 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -1067,10 +1067,18 @@ static int tegra_crtc_setup_clk(struct drm_crtc *crtc,
 		return -ENODEV;
 
 	/*
+	 * The ->setup_clock() callback is optional, but if encoders don't
+	 * implement it they most likely need to do the equivalent within the
+	 * ->mode_fixup() callback.
+	 */
+	if (!output->ops || !output->ops->setup_clock)
+		return 0;
+
+	/*
 	 * This assumes that the parent clock is pll_d_out0 or pll_d2_out
 	 * respectively, each of which divides the base pll_d by 2.
 	 */
-	err = tegra_output_setup_clock(output, dc->clk, pclk, &div);
+	err = output->ops->setup_clock(output, dc->clk, pclk, &div);
 	if (err < 0) {
 		dev_err(dc->dev, "failed to setup clock: %ld\n", err);
 		return err;