diff options
Diffstat (limited to 'drivers/irqchip/irq-loongson-htvec.c')
| -rw-r--r-- | drivers/irqchip/irq-loongson-htvec.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-loongson-htvec.c b/drivers/irqchip/irq-loongson-htvec.c new file mode 100644 index 000000000..60a335d7e --- /dev/null +++ b/drivers/irqchip/irq-loongson-htvec.c @@ -0,0 +1,218 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com> + * Loongson HyperTransport Interrupt Vector support + */ + +#define pr_fmt(fmt) "htvec: " fmt + +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> + +/* Registers */ +#define HTVEC_EN_OFF 0x20 +#define HTVEC_MAX_PARENT_IRQ 8 + +#define VEC_COUNT_PER_REG 32 +#define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG) +#define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG) + +struct htvec { + int num_parents; + void __iomem *base; + struct irq_domain *htvec_domain; + raw_spinlock_t htvec_lock; +}; + +static void htvec_irq_dispatch(struct irq_desc *desc) +{ + int i; + u32 pending; + bool handled = false; + struct irq_chip *chip = irq_desc_get_chip(desc); + struct htvec *priv = irq_desc_get_handler_data(desc); + + chained_irq_enter(chip, desc); + + for (i = 0; i < priv->num_parents; i++) { + pending = readl(priv->base + 4 * i); + while (pending) { + int bit = __ffs(pending); + + generic_handle_domain_irq(priv->htvec_domain, + bit + VEC_COUNT_PER_REG * i); + pending &= ~BIT(bit); + handled = true; + } + } + + if (!handled) + spurious_interrupt(); + + chained_irq_exit(chip, desc); +} + +static void htvec_ack_irq(struct irq_data *d) +{ + struct htvec *priv = irq_data_get_irq_chip_data(d); + + writel(BIT(VEC_REG_BIT(d->hwirq)), + priv->base + VEC_REG_IDX(d->hwirq) * 4); +} + +static void htvec_mask_irq(struct irq_data *d) +{ + u32 reg; + void __iomem *addr; + struct htvec *priv = irq_data_get_irq_chip_data(d); + + raw_spin_lock(&priv->htvec_lock); + addr = priv->base + HTVEC_EN_OFF; + addr += VEC_REG_IDX(d->hwirq) * 4; + reg = readl(addr); + reg &= ~BIT(VEC_REG_BIT(d->hwirq)); + writel(reg, addr); + raw_spin_unlock(&priv->htvec_lock); +} + +static void htvec_unmask_irq(struct irq_data *d) +{ + u32 reg; + void __iomem *addr; + struct htvec *priv = irq_data_get_irq_chip_data(d); + + raw_spin_lock(&priv->htvec_lock); + addr = priv->base + HTVEC_EN_OFF; + addr += VEC_REG_IDX(d->hwirq) * 4; + reg = readl(addr); + reg |= BIT(VEC_REG_BIT(d->hwirq)); + writel(reg, addr); + raw_spin_unlock(&priv->htvec_lock); +} + +static struct irq_chip htvec_irq_chip = { + .name = "LOONGSON_HTVEC", + .irq_mask = htvec_mask_irq, + .irq_unmask = htvec_unmask_irq, + .irq_ack = htvec_ack_irq, +}; + +static int htvec_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + int ret; + unsigned long hwirq; + unsigned int type, i; + struct htvec *priv = domain->host_data; + + ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) { + irq_domain_set_info(domain, virq + i, hwirq + i, &htvec_irq_chip, + priv, handle_edge_irq, NULL, NULL); + } + + return 0; +} + +static void htvec_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + int i; + + for (i = 0; i < nr_irqs; i++) { + struct irq_data *d = irq_domain_get_irq_data(domain, virq + i); + + irq_set_handler(virq + i, NULL); + irq_domain_reset_irq_data(d); + } +} + +static const struct irq_domain_ops htvec_domain_ops = { + .translate = irq_domain_translate_onecell, + .alloc = htvec_domain_alloc, + .free = htvec_domain_free, +}; + +static void htvec_reset(struct htvec *priv) +{ + u32 idx; + + /* Clear IRQ cause registers, mask all interrupts */ + for (idx = 0; idx < priv->num_parents; idx++) { + writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx); + writel_relaxed(0xFFFFFFFF, priv->base + 4 * idx); + } +} + +static int htvec_of_init(struct device_node *node, + struct device_node *parent) +{ + struct htvec *priv; + int err, parent_irq[8], i; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + raw_spin_lock_init(&priv->htvec_lock); + priv->base = of_iomap(node, 0); + if (!priv->base) { + err = -ENOMEM; + goto free_priv; + } + + /* Interrupt may come from any of the 8 interrupt lines */ + for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) { + parent_irq[i] = irq_of_parse_and_map(node, i); + if (parent_irq[i] <= 0) + break; + + priv->num_parents++; + } + + if (!priv->num_parents) { + pr_err("Failed to get parent irqs\n"); + err = -ENODEV; + goto iounmap_base; + } + + priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node), + (VEC_COUNT_PER_REG * priv->num_parents), + &htvec_domain_ops, priv); + if (!priv->htvec_domain) { + pr_err("Failed to create IRQ domain\n"); + err = -ENOMEM; + goto irq_dispose; + } + + htvec_reset(priv); + + for (i = 0; i < priv->num_parents; i++) + irq_set_chained_handler_and_data(parent_irq[i], + htvec_irq_dispatch, priv); + + return 0; + +irq_dispose: + for (; i > 0; i--) + irq_dispose_mapping(parent_irq[i - 1]); +iounmap_base: + iounmap(priv->base); +free_priv: + kfree(priv); + + return err; +} + +IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init); |