diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/irqchip/irq-loongson-pch-lpc.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-loongson-pch-lpc.c b/drivers/irqchip/irq-loongson-pch-lpc.c new file mode 100644 index 000000000..bf2324910 --- /dev/null +++ b/drivers/irqchip/irq-loongson-pch-lpc.c @@ -0,0 +1,205 @@ +// 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; +} |