[PATCH 2/2] pinctrl: renesas: rzt2h: Skip PFC mode configuration if already set

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

In rzt2h_pinctrl_set_pfc_mode(), read the PMC and PFC registers upfront
and skip the pin function configuration if the pin is already in
peripheral mode with the desired function.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
 drivers/pinctrl/renesas/pinctrl-rzt2h.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rzt2h.c b/drivers/pinctrl/renesas/pinctrl-rzt2h.c
index 4b790fa72b49..3945c891248b 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzt2h.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzt2h.c
@@ -188,8 +188,18 @@ static void rzt2h_pinctrl_set_pfc_mode(struct rzt2h_pinctrl *pctrl,
 {
 	u64 reg64;
 	u16 reg16;
+	u8 pmc;
 
 	guard(raw_spinlock_irqsave)(&pctrl->lock);
+	reg64 = rzt2h_pinctrl_readq(pctrl, port, PFC(port));
+	pmc = rzt2h_pinctrl_readb(pctrl, port, PMC(port));
+	/* Check if pin is already configured to the desired function */
+	if (pmc & BIT(pin)) {
+		u8 current_func = field_get(PFC_PIN_MASK(pin), reg64);
+
+		if (current_func == func)
+			return;
+	}
 
 	/* Set pin to 'Non-use (Hi-Z input protection)'  */
 	reg16 = rzt2h_pinctrl_readw(pctrl, port, PM(port));
@@ -200,7 +210,6 @@ static void rzt2h_pinctrl_set_pfc_mode(struct rzt2h_pinctrl *pctrl,
 	rzt2h_pinctrl_set_gpio_en(pctrl, port, pin, true);
 
 	/* Select Pin function mode with PFC register */
-	reg64 = rzt2h_pinctrl_readq(pctrl, port, PFC(port));
 	reg64 &= ~PFC_PIN_MASK(pin);
 	rzt2h_pinctrl_writeq(pctrl, port, reg64 | ((u64)func << (pin * 8)), PFC(port));
 
-- 
2.54.0