linux-kernel - [PATCH v1 2/5] pinctrl: microchip-sgpio: don't do RMW for interrupt ack register

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Date:   Thu, 24 Feb 2022 17:10:18 +0100
From:   Michael Walle <michael@...le.cc>
To:     Lars Povlsen <lars.povlsen@...rochip.com>,
        Steen Hegelund <Steen.Hegelund@...rochip.com>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     UNGLinuxDriver@...rochip.com, linux-arm-kernel@...ts.infradead.org,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Colin Foster <colin.foster@...advantage.com>,
        Michael Walle <michael@...le.cc>
Subject: [PATCH v1 2/5] pinctrl: microchip-sgpio: don't do RMW for interrupt ack register

The interrupt ack register has the usual "write one to clear" semantics.
No read-modify-write is required here.

This is also a preparation patch to change the sgpio_clrsetbits() to use
regmap_update_bits() which don't write the value if it is not changed.

Signed-off-by: Michael Walle <michael@...le.cc>
---
 drivers/pinctrl/pinctrl-microchip-sgpio.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
index b43302cc188a..31c4401f725e 100644
--- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
+++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
@@ -640,7 +640,14 @@ static void microchip_sgpio_irq_unmask(struct irq_data *data)
 
 static void microchip_sgpio_irq_ack(struct irq_data *data)
 {
-	microchip_sgpio_irq_setreg(data, REG_INT_ACK, false);
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
+	struct sgpio_bank *bank = gpiochip_get_data(chip);
+	unsigned int gpio = irqd_to_hwirq(data);
+	struct sgpio_port_addr addr;
+
+	sgpio_pin_to_addr(bank->priv, gpio, &addr);
+
+	sgpio_writel(bank->priv, BIT(addr.port), REG_INT_ACK, addr.bit);
 }
 
 static int microchip_sgpio_irq_set_type(struct irq_data *data, unsigned int type)
-- 
2.30.2