--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Loongson LPC Interrupt Controller support
+ *
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+
+#define pr_fmt(fmt) "lpc: " fmt
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+
+/* Registers */
+#define LPC_INT_CTL 0x00
+#define LPC_INT_ENA 0x04
+#define LPC_INT_STS 0x08
+#define LPC_INT_CLR 0x0c
+#define LPC_INT_POL 0x10
+#define LPC_COUNT 16
+
+/* LPC_INT_CTL */
+#define LPC_INT_CTL_EN BIT(31)
+
+struct pch_lpc {
+ void __iomem *base;
+ struct irq_domain *lpc_domain;
+ raw_spinlock_t lpc_lock;
+ u32 saved_reg_ctl;
+ u32 saved_reg_ena;
+ u32 saved_reg_pol;
+};
+
+struct fwnode_handle *pch_lpc_handle;
+
+static void lpc_irq_ack(struct irq_data *d)
+{
+ unsigned long flags;
+ struct pch_lpc *priv = d->domain->host_data;
+
+ raw_spin_lock_irqsave(&priv->lpc_lock, flags);
+ writel(0x1 << d->hwirq, priv->base + LPC_INT_CLR);
+ raw_spin_unlock_irqrestore(&priv->lpc_lock, flags);
+}
+
+static void lpc_irq_mask(struct irq_data *d)
+{
+ unsigned long flags;
+ struct pch_lpc *priv = d->domain->host_data;
+
+ raw_spin_lock_irqsave(&priv->lpc_lock, flags);
+ writel(readl(priv->base + LPC_INT_ENA) & (~(0x1 << (d->hwirq))),
+ priv->base + LPC_INT_ENA);
+ raw_spin_unlock_irqrestore(&priv->lpc_lock, flags);
+}
+
+static void lpc_irq_unmask(struct irq_data *d)
+{
+ unsigned long flags;
+ struct pch_lpc *priv = d->domain->host_data;
+
+ raw_spin_lock_irqsave(&priv->lpc_lock, flags);
+ writel(readl(priv->base + LPC_INT_ENA) | (0x1 << (d->hwirq)),
+ priv->base + LPC_INT_ENA);
+ raw_spin_unlock_irqrestore(&priv->lpc_lock, flags);
+}
+
+static int lpc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ u32 val;
+ u32 mask = 0x1 << (d->hwirq);
+ struct pch_lpc *priv = d->domain->host_data;
+
+ if (!(type & IRQ_TYPE_LEVEL_MASK))
+ return 0;
+
+ val = readl(priv->base + LPC_INT_POL);
+
+ if (type == IRQ_TYPE_LEVEL_HIGH)
+ val |= mask;
+ else
+ val &= ~mask;
+
+ writel(val, priv->base + LPC_INT_POL);
+
+ return 0;
+}
+
+static const struct irq_chip pch_lpc_irq_chip = {
+ .name = "PCH LPC",
+ .irq_mask = lpc_irq_mask,
+ .irq_unmask = lpc_irq_unmask,
+ .irq_ack = lpc_irq_ack,
+ .irq_set_type = lpc_irq_set_type,
+ .flags = IRQCHIP_SKIP_SET_WAKE,
+};
+
+static void lpc_irq_dispatch(struct irq_desc *desc)
+{
+ u32 pending, bit;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct pch_lpc *priv = irq_desc_get_handler_data(desc);
+
+ chained_irq_enter(chip, desc);
+
+ pending = readl(priv->base + LPC_INT_ENA);
+ pending &= readl(priv->base + LPC_INT_STS);
+ if (!pending)
+ spurious_interrupt();
+
+ while (pending) {
+ bit = __ffs(pending);
+
+ generic_handle_domain_irq(priv->lpc_domain, bit);
+ pending &= ~BIT(bit);
+ }
+ chained_irq_exit(chip, desc);
+}
+
+static int pch_lpc_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(irq, &pch_lpc_irq_chip, handle_level_irq);
+ return 0;
+}
+
+static const struct irq_domain_ops pch_lpc_domain_ops = {
+ .map = pch_lpc_map,
+ .translate = irq_domain_translate_twocell,
+};
+
+static void pch_lpc_reset(struct pch_lpc *priv)
+{
+ /* Enable the LPC interrupt, bit31: en bit30: edge */
+ writel(LPC_INT_CTL_EN, priv->base + LPC_INT_CTL);
+ writel(0, priv->base + LPC_INT_ENA);
+ /* Clear all 18-bit interrpt bit */
+ writel(GENMASK(17, 0), priv->base + LPC_INT_CLR);
+}
+
+static int pch_lpc_disabled(struct pch_lpc *priv)
+{
+ return (readl(priv->base + LPC_INT_ENA) == 0xffffffff) &&
+ (readl(priv->base + LPC_INT_STS) == 0xffffffff);
+}
+
+int __init pch_lpc_acpi_init(struct irq_domain *parent,
+ struct acpi_madt_lpc_pic *acpi_pchlpc)
+{
+ int parent_irq;
+ struct pch_lpc *priv;
+ struct irq_fwspec fwspec;
+ struct fwnode_handle *irq_handle;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ raw_spin_lock_init(&priv->lpc_lock);
+
+ priv->base = ioremap(acpi_pchlpc->address, acpi_pchlpc->size);
+ if (!priv->base)
+ goto free_priv;
+
+ if (pch_lpc_disabled(priv)) {
+ pr_err("Failed to get LPC status\n");
+ goto iounmap_base;
+ }
+
+ irq_handle = irq_domain_alloc_named_fwnode("lpcintc");
+ if (!irq_handle) {
+ pr_err("Unable to allocate domain handle\n");
+ goto iounmap_base;
+ }
+
+ priv->lpc_domain = irq_domain_create_linear(irq_handle, LPC_COUNT,
+ &pch_lpc_domain_ops, priv);
+ if (!priv->lpc_domain) {
+ pr_err("Failed to create IRQ domain\n");
+ goto free_irq_handle;
+ }
+ pch_lpc_reset(priv);
+
+ fwspec.fwnode = parent->fwnode;
+ fwspec.param[0] = acpi_pchlpc->cascade + GSI_MIN_PCH_IRQ;
+ fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
+ fwspec.param_count = 2;
+ parent_irq = irq_create_fwspec_mapping(&fwspec);
+ irq_set_chained_handler_and_data(parent_irq, lpc_irq_dispatch, priv);
+
+ pch_lpc_handle = irq_handle;
+ return 0;
+
+free_irq_handle:
+ irq_domain_free_fwnode(irq_handle);
+iounmap_base:
+ iounmap(priv->base);
+free_priv:
+ kfree(priv);
+
+ return -ENOMEM;
+}
projects / platform / kernel / linux-starfive.git / commitdiff