linux-kernel - [PATCH] pinctrl: amd: Implement irq_set

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Date:   Thu, 29 Apr 2021 16:34:24 -0600
From:   Raul E Rangel <rrangel@...omium.org>
To:     linux-gpio@...r.kernel.org
Cc:     kramasub@...omium.org, Raul E Rangel <rrangel@...omium.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH] pinctrl: amd: Implement irq_set_wake

This allows the OS to control which devices produce wake events.

$ grep enabled /sys/kernel/irq/*/wakeup
/sys/kernel/irq/24/wakeup:enabled

Signed-off-by: Raul E Rangel <rrangel@...omium.org>
---

 drivers/pinctrl/pinctrl-amd.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index 899c16c17b6d..27ad759e5958 100644
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -399,6 +399,29 @@ static void amd_gpio_irq_unmask(struct irq_data *d)
 	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
 }
 
+static int amd_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+	u32 pin_reg;
+	unsigned long flags;
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);
+	u32 wake_mask = BIT(WAKE_CNTRL_OFF_S0I3) | BIT(WAKE_CNTRL_OFF_S3) |
+			BIT(WAKE_CNTRL_OFF_S4);
+
+	raw_spin_lock_irqsave(&gpio_dev->lock, flags);
+	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
+
+	if (on)
+		pin_reg |= wake_mask;
+	else
+		pin_reg &= ~wake_mask;
+
+	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);
+	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
+
+	return 0;
+}
+
 static void amd_gpio_irq_eoi(struct irq_data *d)
 {
 	u32 reg;
@@ -513,9 +536,16 @@ static struct irq_chip amd_gpio_irqchip = {
 	.irq_disable  = amd_gpio_irq_disable,
 	.irq_mask     = amd_gpio_irq_mask,
 	.irq_unmask   = amd_gpio_irq_unmask,
+	.irq_set_wake = amd_gpio_irq_set_wake,
 	.irq_eoi      = amd_gpio_irq_eoi,
 	.irq_set_type = amd_gpio_irq_set_type,
-	.flags        = IRQCHIP_SKIP_SET_WAKE,
+	/*
+	 * We need to set IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND so that a wake event
+	 * also generates an IRQ. We need the IRQ so the irq_handler can clear
+	 * the wake event. Otherwise the wake event will never clear and
+	 * prevent the system from suspending.
+	 */
+	.flags        = IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND,
 };
 
 #define PIN_IRQ_PENDING	(BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF))
-- 
2.31.1.527.g47e6f16901-goog