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Commit 2198c2c1 authored by Jernej Skrabec's avatar Jernej Skrabec Committed by Greg Kroah-Hartman
Browse files

drm/sun4i: Initialize registers in tcon-top driver 



[ Upstream commit c96d62215fb540e2ae61de44cb7caf4db50958e3 ]

It turns out that TCON TOP registers in H6 SoC have non-zero reset
value. This may cause issues if bits are not changed during
configuration.

To prevent that, initialize registers to 0.

Signed-off-by: default avatarJernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181104182705.18047-24-jernej.skrabec@siol.net


Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 3555de57

drivers/gpu/drm/sun4i/sun8i_tcon_top.c

+7 −0
Original line number Diff line number Diff line
@@ -168,6 +168,13 @@ static int sun8i_tcon_top_bind(struct device *dev, struct device *master, 
		goto err_assert_reset;

	}



	/*

	 * At least on H6, some registers have some bits set by default

	 * which may cause issues. Clear them here.

	 */

	writel(0, regs + TCON_TOP_PORT_SEL_REG);

	writel(0, regs + TCON_TOP_GATE_SRC_REG);



	/*

	 * TCON TOP has two muxes, which select parent clock for each TCON TV

	 * channel clock. Parent could be either TCON TV or TVE clock. For now