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From:   Huacai Chen <chenhuacai@loongson.cn>
To:     Thomas Gleixner <tglx@linutronix.de>, Marc Zyngier <maz@kernel.org>
Cc:     linux-kernel@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>,
        Huacai Chen <chenhuacai@gmail.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Huacai Chen <chenhuacai@loongson.cn>
Subject: [PATCH 3/4] irqchip/loongson-pch-pic: Add suspend/resume support
Date:   Mon, 17 Oct 2022 11:39:03 +0800
Message-Id: <20221017033904.2421723-4-chenhuacai@loongson.cn>
In-Reply-To: <20221017033904.2421723-1-chenhuacai@loongson.cn>
References: <20221017033904.2421723-1-chenhuacai@loongson.cn>
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Add suspend/resume support for PCH-PIC irqchip, which is needed for
upcoming suspend/hibernation.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 drivers/irqchip/irq-loongson-pch-pic.c | 47 ++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
index c01b9c257005..217513d74664 100644
--- a/drivers/irqchip/irq-loongson-pch-pic.c
+++ b/drivers/irqchip/irq-loongson-pch-pic.c
@@ -15,6 +15,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/syscore_ops.h>
 
 /* Registers */
 #define PCH_PIC_MASK		0x20
@@ -42,6 +43,9 @@ struct pch_pic {
 	raw_spinlock_t		pic_lock;
 	u32			vec_count;
 	u32			gsi_base;
+	u32			saved_vec_en[PIC_REG_COUNT];
+	u32			saved_vec_pol[PIC_REG_COUNT];
+	u32			saved_vec_edge[PIC_REG_COUNT];
 };
 
 static struct pch_pic *pch_pic_priv[MAX_IO_PICS];
@@ -145,6 +149,7 @@ static struct irq_chip pch_pic_irq_chip = {
 	.irq_ack		= pch_pic_ack_irq,
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 	.irq_set_type		= pch_pic_set_type,
+	.flags			= IRQCHIP_SKIP_SET_WAKE,
 };
 
 static int pch_pic_domain_translate(struct irq_domain *d,
@@ -228,6 +233,46 @@ static void pch_pic_reset(struct pch_pic *priv)
 	}
 }
 
+static int pch_pic_suspend(void)
+{
+	int i, j;
+
+	for (i = 0; i < nr_pics; i++) {
+		for (j = 0; j < PIC_REG_COUNT; j++) {
+			pch_pic_priv[i]->saved_vec_pol[j] =
+				readl(pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
+			pch_pic_priv[i]->saved_vec_edge[j] =
+				readl(pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
+			pch_pic_priv[i]->saved_vec_en[j] =
+				readl(pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
+		}
+	}
+
+	return 0;
+}
+
+static void pch_pic_resume(void)
+{
+	int i, j;
+
+	for (i = 0; i < nr_pics; i++) {
+		pch_pic_reset(pch_pic_priv[i]);
+		for (j = 0; j < PIC_REG_COUNT; j++) {
+			writel(pch_pic_priv[i]->saved_vec_pol[j],
+					pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
+			writel(pch_pic_priv[i]->saved_vec_edge[j],
+					pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
+			writel(pch_pic_priv[i]->saved_vec_en[j],
+					pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
+		}
+	}
+}
+
+static struct syscore_ops pch_pic_syscore_ops = {
+	.suspend =  pch_pic_suspend,
+	.resume =  pch_pic_resume,
+};
+
 static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
 			struct irq_domain *parent_domain, struct fwnode_handle *domain_handle,
 			u32 gsi_base)
@@ -260,6 +305,8 @@ static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
 	pch_pic_handle[nr_pics] = domain_handle;
 	pch_pic_priv[nr_pics++] = priv;
 
+	register_syscore_ops(&pch_pic_syscore_ops);
+
 	return 0;
 
 iounmap_base:
-- 
2.31.1