[PATCH V3 03/15] clk: imx: composite-7ulp: Check the PCC present bit

[Peng Fan (OSS)]

From: Ye Li <ye.li@xxxxxxx>

When some module is disabled by fuse, its PCC PR bit is default 0 and
PCC is not operational. Any write to this PCC will cause SError.

Fixes: b40ba8065347 ("clk: imx: Update the compsite driver to support imx8ulp")
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
Signed-off-by: Ye Li <ye.li@xxxxxxx>
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
 drivers/clk/imx/clk-composite-7ulp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/clk/imx/clk-composite-7ulp.c b/drivers/clk/imx/clk-composite-7ulp.c
index e208ddc51133..db7f40b07d1a 100644
--- a/drivers/clk/imx/clk-composite-7ulp.c
+++ b/drivers/clk/imx/clk-composite-7ulp.c
@@ -14,6 +14,7 @@
 #include "../clk-fractional-divider.h"
 #include "clk.h"
 
+#define PCG_PR_MASK		BIT(31)
 #define PCG_PCS_SHIFT	24
 #define PCG_PCS_MASK	0x7
 #define PCG_CGC_SHIFT	30
@@ -78,6 +79,12 @@ static struct clk_hw *imx_ulp_clk_hw_composite(const char *name,
 	struct clk_hw *hw;
 	u32 val;
 
+	val = readl(reg);
+	if (!(val & PCG_PR_MASK)) {
+		pr_info("PCC PR is 0 for clk:%s, bypass\n", name);
+		return 0;
+	}
+
 	if (mux_present) {
 		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
 		if (!mux)
-- 
2.37.1