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

From: Frank Oltmanns
Date: Fri Aug 25 2023 - 01:38:04 EST


From: Icenowy Zheng <icenowy@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>
---
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