drivers: clk: stm32: fix stm32mp13 clock gates initialization

Correct STM32MP13 clock gates initialization regarding the enable
reference counting. The fixed commit introduced side effect where
clock gates with a disable init state overflow the gate refcount to -1
and clock gates with a enable init state take a refcount that is never
released.

For this purpose, add stm32_gate_set_init_state() function in
stm32 clock core driver for STM32MP13 gate clocks initialization
expects to set some clock gate hardware state (enabled or disabled)
before any refcount is considered.

Fixes: 2b028a2 ("clk: implement multi-gate management at core level")
Signed-off-by: Etienne Carriere <[email protected]>

core/drivers/clk/clk-stm32-core.c

@@ -87,6 +87,14 @@ static void stm32_gate_endisable(uint16_t gate_id, bool enable)
 	}
 }
 
+void stm32_gate_set_init_state(uint16_t gate_id, bool enable)
+{
+	struct clk_stm32_priv __maybe_unused *priv = clk_stm32_get_priv();
+
+	assert(!priv->gate_cpt[gate_id]);
+	stm32_gate_endisable(gate_id, enable);
+}
+
 void stm32_gate_disable(uint16_t gate_id)
 {
 	struct clk_stm32_priv *priv = clk_stm32_get_priv();

core/drivers/clk/clk-stm32-core.h

@@ -120,6 +120,13 @@ TEE_Result stm32_gate_wait_ready(uint16_t gate_id, bool ready_on);
 TEE_Result stm32_gate_rdy_enable(uint16_t gate_id);
 TEE_Result stm32_gate_rdy_disable(uint16_t gate_id);
 
+/*
+ * Set gate to an enable or disable state without updating its
+ * refcount. This is exclusively intended to be used during initialization
+ * where refcount value are 0.
+ */
+void stm32_gate_set_init_state(uint16_t gate_id, bool enable);
+
 size_t stm32_mux_get_parent(uint32_t mux_id);
 TEE_Result stm32_mux_set_parent(uint16_t pid, uint8_t sel);
 

core/drivers/clk/clk-stm32mp13.c

@@ -964,10 +964,7 @@ static int stm32_clk_configure_clk(struct clk_stm32_priv *priv __maybe_unused,
 	if (stm32_mux_set_parent(mux, sel))
 		return -1;
 
-	if (enable)
-		stm32_gate_enable(gate);
-	else
-		stm32_gate_disable(gate);
+	stm32_gate_set_init_state(gate, enable);
 
 	return 0;
 }