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

From: Frank Oltmanns
Date: Sun Mar 10 2024 - 09:22:48 EST


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@xxxxxxxxxx>
Closes: https://groups.google.com/g/linux-sunxi/c/Rh-Uqqa66bw
Tested-by: Diego Roversi <diegor@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Maxime Ripard <mripard@xxxxxxxxxx>
Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>
---
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