[PATCH 2/2] clk: spacemit: k3: add 1.8 GHz PLL5 and PLL8 rates

Troy Mitchell <[email protected]> Tue, 04 Aug 2026 00:02:56 -0700
Newsgroups org.kernel.vger.linux-clk,dev.linux.lists.spacemit,org.infradead.lists.linux-riscv,org.kernel.vger.linux-kernel
Message-ID <20260804-k3-pll5-pll8-1800mhz-v1-2-a3a75866ce32@linux.spacemit.com>
The K3 SoC may not remain stable when its A100 CPU clusters operate
persistently at 2 GHz. Updated U-Boot firmware therefore configures
their C2 and C3 clock domains at 1.8 GHz during early initialization.
PLL5 feeds C2 and PLL8 feeds C3, but 2 GHz is currently the only entry
in both rate tables.

Add 1.8 GHz as the first entry in the PLL5 and PLL8 rate tables,
switching the driver default from 2 GHz to 1.8 GHz.

Signed-off-by: Troy Mitchell <[email protected]>
---
 drivers/clk/spacemit/ccu-k3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clk/spacemit/ccu-k3.c b/drivers/clk/spacemit/ccu-k3.c
index cb0c4277f72a..e8b7ce89c2cb 100644
--- a/drivers/clk/spacemit/ccu-k3.c
+++ b/drivers/clk/spacemit/ccu-k3.c
@@ -38,6 +38,7 @@ static const struct ccu_pll_rate_tbl pll4_rate_tbl[] = {
 };
 
 static const struct ccu_pll_rate_tbl pll5_rate_tbl[] = {
+	CCU_PLLA_RATE(1800000000UL, 0x0b4b0000, 0x00000000, 0xa0458585),
 	CCU_PLLA_RATE(2000000000UL, 0x0b292aaa, 0x0000ab00, 0xa0558686),
 };
 
@@ -50,6 +51,7 @@ static const struct ccu_pll_rate_tbl pll7_rate_tbl[] = {
 };
 
 static const struct ccu_pll_rate_tbl pll8_rate_tbl[] = {
+	CCU_PLLA_RATE(1800000000UL, 0x0b4b0000, 0x00000000, 0xa0458585),
 	CCU_PLLA_RATE(2000000000UL, 0x0b292aaa, 0x0000ab00, 0xa0558686),
 };
 

-- 
2.55.0