diff mbox series

[v3,2/4] clk: renesas: rcar-gen3-cpg: add spinlock

Message ID 8a630f60-c5a1-de98-f80a-40404199d8bd@cogentembedded.com (mailing list archive)
State Accepted
Delegated to: Geert Uytterhoeven
Headers show
Series Renesas R8A77980 CPG/MSSR RPC clock support | expand

Commit Message

Sergei Shtylyov Jan. 22, 2019, 7:58 p.m. UTC 
Protect the CPG register read-modify-write sequence with a spinlock.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

---
Changes in version 3:
- refreshed the patch;
- added Geert's tag.

Changes in version 2:
- new patch.

 drivers/clk/renesas/rcar-gen3-cpg.c |    8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

Index: renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.c
===================================================================
--- renesas-drivers.orig/drivers/clk/renesas/rcar-gen3-cpg.c
+++ renesas-drivers/drivers/clk/renesas/rcar-gen3-cpg.c
@@ -30,14 +30,19 @@ 
 
 #define CPG_RCKCR_CKSEL	BIT(15)	/* RCLK Clock Source Select */
 
+static spinlock_t cpg_lock;
+
 static void cpg_reg_modify(void __iomem *reg, u32 clear, u32 set)
 {
+	unsigned long flags;
 	u32 val;
 
+	spin_lock_irqsave(&cpg_lock, flags);
 	val = readl(reg);
 	val &= ~clear;
 	val |= set;
 	writel(val, reg);
+	spin_unlock_irqrestore(&cpg_lock, flags);
 };
 
 struct cpg_simple_notifier {
@@ -615,5 +620,8 @@  int __init rcar_gen3_cpg_init(const stru
 	if (attr)
 		cpg_quirks = (uintptr_t)attr->data;
 	pr_debug("%s: mode = 0x%x quirks = 0x%x\n", __func__, mode, cpg_quirks);
+
+	spin_lock_init(&cpg_lock);
+
 	return 0;
 }