[PATCH v4 2/5] clk: sunxi-ng: a64: Set minimum and maximum rate for PLL-MIPI

Frank Oltmanns frank at oltmanns.dev
Sun Mar 10 06:21:12 PDT 2024


When the Allwinner A64's TCON0 searches the ideal rate for the connected
panel, it may happen that it requests a rate from its parent PLL-MIPI
which PLL-MIPI does not support.

This happens for example on the Olimex TERES-I laptop where TCON0
requests PLL-MIPI to change to a rate of several GHz which causes the
panel to stay blank. It also happens on the pinephone where a rate of
less than 500 MHz is requested which causes instabilities on some
phones.

Set the minimum and maximum rate of Allwinner A64's PLL-MIPI according
to the Allwinner User Manual.

Fixes: ca1170b69968 ("clk: sunxi-ng: a64: force select PLL_MIPI in TCON0 mux")
Reported-by: Diego Roversi <diegor at tiscali.it>
Closes: https://groups.google.com/g/linux-sunxi/c/Rh-Uqqa66bw
Tested-by: Diego Roversi <diegor at tiscali.it>
Cc: stable at vger.kernel.org
Reviewed-by: Maxime Ripard <mripard at kernel.org>
Signed-off-by: Frank Oltmanns <frank at oltmanns.dev>
---
 drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
index 8951ffc14ff5..6a4b2b9ef30a 100644
--- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
+++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c
@@ -182,6 +182,8 @@ static struct ccu_nkm pll_mipi_clk = {
 					      &ccu_nkm_ops,
 					      CLK_SET_RATE_UNGATE | CLK_SET_RATE_PARENT),
 		.features	= CCU_FEATURE_CLOSEST_RATE,
+		.min_rate	= 500000000,
+		.max_rate	= 1400000000,
 	},
 };
 

-- 
2.44.0




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