[PATCH 3/3] drm/sun4i: tcon: parent keeps TCON0 clock stable on A64

[Frank Oltmanns]

From: Icenowy Zheng <icenowy at aosc.io>

As the clk framework keeps A64's TCON0 clock stable when HDMI changes
its parent's clock, do not protect TCON0 clock on A64 in the TCON driver
to allow PLL-Video0 to get changed by HDMI.

Signed-off-by: Icenowy Zheng <icenowy at aosc.io>
Signed-off-by: Frank Oltmanns <frank at oltmanns.dev>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 +++++++++++++--
 drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 6a52fb12cbfb..4439e62b7a34 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -108,9 +108,11 @@ static void sun4i_tcon_channel_set_status(struct sun4i_tcon *tcon, int channel,
 
 	if (enabled) {
 		clk_prepare_enable(clk);
-		clk_rate_exclusive_get(clk);
+		if (!tcon->quirks->rate_kept_by_parent)
+			clk_rate_exclusive_get(clk);
 	} else {
-		clk_rate_exclusive_put(clk);
+		if (!tcon->quirks->rate_kept_by_parent)
+			clk_rate_exclusive_put(clk);
 		clk_disable_unprepare(clk);
 	}
 }
@@ -1505,6 +1507,14 @@ static const struct sun4i_tcon_quirks sun8i_a33_quirks = {
 	.supports_lvds		= true,
 };
 
+static const struct sun4i_tcon_quirks sun50i_a64_lcd_quirks = {
+	.supports_lvds		= true,
+	.has_channel_0		= true,
+	.rate_kept_by_parent	= true,
+	.dclk_min_div		= 1,
+	.setup_lvds_phy		= sun6i_tcon_setup_lvds_phy,
+};
+
 static const struct sun4i_tcon_quirks sun8i_a83t_lcd_quirks = {
 	.supports_lvds		= true,
 	.has_channel_0		= true,
@@ -1563,6 +1573,7 @@ const struct of_device_id sun4i_tcon_of_table[] = {
 	{ .compatible = "allwinner,sun9i-a80-tcon-tv", .data = &sun9i_a80_tcon_tv_quirks },
 	{ .compatible = "allwinner,sun20i-d1-tcon-lcd", .data = &sun20i_d1_lcd_quirks },
 	{ .compatible = "allwinner,sun20i-d1-tcon-tv", .data = &sun8i_r40_tv_quirks },
+	{ .compatible = "allwinner,sun50i-a64-tcon-lcd", .data = &sun50i_a64_lcd_quirks },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sun4i_tcon_of_table);
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index fa23aa23fe4a..c4ce7c29192e 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -243,6 +243,7 @@ struct sun4i_tcon_quirks {
 	bool    needs_edp_reset; /* a80 edp reset needed for tcon0 access */
 	bool	supports_lvds;   /* Does the TCON support an LVDS output? */
 	bool	polarity_in_ch0; /* some tcon1 channels have polarity bits in tcon0 pol register */
+	bool	rate_kept_by_parent; /* Does parent keep TCON0 clock stable? */
 	u8	dclk_min_div;	/* minimum divider for TCON0 DCLK */
 
 	/* callback to handle tcon muxing options */

-- 
2.41.0