drm/sun4i: drc: Make sure we enforce the clock rate (6fe082b0) · Commits · 戴 / test

The DRC needs to run at 300MHz to be functional. This was done so far using assigned-clocks in the device tree, but that is easy to forget, and doesn't provide any other guarantee than the rate is going to be roughly the one requested at probe time. Therefore it's pretty fragile, so let's just use the exclusive clock API to enforce it. Reviewed-by:

Chen-Yu Tsai <wens@csie.org> Signed-off-by:

Maxime Ripard <maxime@cerno.tech> Link: https://patchwork.freedesktop.org/patch/msgid/20200107165957.672435-2-maxime@cerno.tech

drivers/gpu/drm/sun4i/sun6i_drc.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,13 @@ static int sun6i_drc_bind(struct device dev, struct device master,
		ret = PTR_ERR(drc->mod_clk);
		goto err_disable_bus_clk;
		}

		ret = clk_set_rate_exclusive(drc->mod_clk, 300000000);
		if (ret) {
		dev_err(dev, "Couldn't set the module clock frequency\n");
		goto err_disable_bus_clk;
		}

		clk_prepare_enable(drc->mod_clk);

		return 0;
		@@ -72,6 +79,7 @@ static void sun6i_drc_unbind(struct device dev, struct device master,
		{
		struct sun6i_drc *drc = dev_get_drvdata(dev);

		clk_rate_exclusive_put(drc->mod_clk);
		clk_disable_unprepare(drc->mod_clk);
		clk_disable_unprepare(drc->bus_clk);
		reset_control_assert(drc->reset);

Admin message