[PATCH V2 4/4] irqchip/loongson-pch-lpc: Add suspend/resume support

From: Huacai Chen
Date: Thu Oct 20 2022 - 03:39:26 EST


Add suspend/resume support for PCH-LPC irqchip, which is needed for
upcoming suspend/hibernation.

Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
drivers/irqchip/irq-loongson-pch-lpc.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/drivers/irqchip/irq-loongson-pch-lpc.c b/drivers/irqchip/irq-loongson-pch-lpc.c
index bf2324910a75..9b35492fb6be 100644
--- a/drivers/irqchip/irq-loongson-pch-lpc.c
+++ b/drivers/irqchip/irq-loongson-pch-lpc.c
@@ -13,6 +13,7 @@
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
+#include <linux/syscore_ops.h>

/* Registers */
#define LPC_INT_CTL 0x00
@@ -34,6 +35,7 @@ struct pch_lpc {
u32 saved_reg_pol;
};

+static struct pch_lpc *pch_lpc_priv;
struct fwnode_handle *pch_lpc_handle;

static void lpc_irq_ack(struct irq_data *d)
@@ -147,6 +149,26 @@ static int pch_lpc_disabled(struct pch_lpc *priv)
(readl(priv->base + LPC_INT_STS) == 0xffffffff);
}

+static int pch_lpc_suspend(void)
+{
+ pch_lpc_priv->saved_reg_ctl = readl(pch_lpc_priv->base + LPC_INT_CTL);
+ pch_lpc_priv->saved_reg_ena = readl(pch_lpc_priv->base + LPC_INT_ENA);
+ pch_lpc_priv->saved_reg_pol = readl(pch_lpc_priv->base + LPC_INT_POL);
+ return 0;
+}
+
+static void pch_lpc_resume(void)
+{
+ writel(pch_lpc_priv->saved_reg_ctl, pch_lpc_priv->base + LPC_INT_CTL);
+ writel(pch_lpc_priv->saved_reg_ena, pch_lpc_priv->base + LPC_INT_ENA);
+ writel(pch_lpc_priv->saved_reg_pol, pch_lpc_priv->base + LPC_INT_POL);
+}
+
+static struct syscore_ops pch_lpc_syscore_ops = {
+ .suspend = pch_lpc_suspend,
+ .resume = pch_lpc_resume,
+};
+
int __init pch_lpc_acpi_init(struct irq_domain *parent,
struct acpi_madt_lpc_pic *acpi_pchlpc)
{
@@ -191,7 +213,10 @@ int __init pch_lpc_acpi_init(struct irq_domain *parent,
parent_irq = irq_create_fwspec_mapping(&fwspec);
irq_set_chained_handler_and_data(parent_irq, lpc_irq_dispatch, priv);

+ pch_lpc_priv = priv;
pch_lpc_handle = irq_handle;
+ register_syscore_ops(&pch_lpc_syscore_ops);
+
return 0;

free_irq_handle:
--
2.31.1