diff options
Diffstat (limited to 'kernel/arch/mips/ralink/irq.c')
| -rw-r--r-- | kernel/arch/mips/ralink/irq.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/kernel/arch/mips/ralink/irq.c b/kernel/arch/mips/ralink/irq.c new file mode 100644 index 000000000..7cf91b92e --- /dev/null +++ b/kernel/arch/mips/ralink/irq.c @@ -0,0 +1,206 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2013 John Crispin <blogic@openwrt.org> + */ + +#include <linux/io.h> +#include <linux/bitops.h> +#include <linux/of_platform.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/irqdomain.h> +#include <linux/interrupt.h> + +#include <asm/irq_cpu.h> +#include <asm/mipsregs.h> + +#include "common.h" + +#define INTC_INT_GLOBAL BIT(31) + +#define RALINK_CPU_IRQ_INTC (MIPS_CPU_IRQ_BASE + 2) +#define RALINK_CPU_IRQ_PCI (MIPS_CPU_IRQ_BASE + 4) +#define RALINK_CPU_IRQ_FE (MIPS_CPU_IRQ_BASE + 5) +#define RALINK_CPU_IRQ_WIFI (MIPS_CPU_IRQ_BASE + 6) +#define RALINK_CPU_IRQ_COUNTER (MIPS_CPU_IRQ_BASE + 7) + +/* we have a cascade of 8 irqs */ +#define RALINK_INTC_IRQ_BASE 8 + +/* we have 32 SoC irqs */ +#define RALINK_INTC_IRQ_COUNT 32 + +#define RALINK_INTC_IRQ_PERFC (RALINK_INTC_IRQ_BASE + 9) + +enum rt_intc_regs_enum { + INTC_REG_STATUS0 = 0, + INTC_REG_STATUS1, + INTC_REG_TYPE, + INTC_REG_RAW_STATUS, + INTC_REG_ENABLE, + INTC_REG_DISABLE, +}; + +static u32 rt_intc_regs[] = { + [INTC_REG_STATUS0] = 0x00, + [INTC_REG_STATUS1] = 0x04, + [INTC_REG_TYPE] = 0x20, + [INTC_REG_RAW_STATUS] = 0x30, + [INTC_REG_ENABLE] = 0x34, + [INTC_REG_DISABLE] = 0x38, +}; + +static void __iomem *rt_intc_membase; + +static int rt_perfcount_irq; + +static inline void rt_intc_w32(u32 val, unsigned reg) +{ + __raw_writel(val, rt_intc_membase + rt_intc_regs[reg]); +} + +static inline u32 rt_intc_r32(unsigned reg) +{ + return __raw_readl(rt_intc_membase + rt_intc_regs[reg]); +} + +static void ralink_intc_irq_unmask(struct irq_data *d) +{ + rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE); +} + +static void ralink_intc_irq_mask(struct irq_data *d) +{ + rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE); +} + +static struct irq_chip ralink_intc_irq_chip = { + .name = "INTC", + .irq_unmask = ralink_intc_irq_unmask, + .irq_mask = ralink_intc_irq_mask, + .irq_mask_ack = ralink_intc_irq_mask, +}; + +int get_c0_perfcount_int(void) +{ + return rt_perfcount_irq; +} + +unsigned int get_c0_compare_int(void) +{ + return CP0_LEGACY_COMPARE_IRQ; +} + +static void ralink_intc_irq_handler(unsigned int irq, struct irq_desc *desc) +{ + u32 pending = rt_intc_r32(INTC_REG_STATUS0); + + if (pending) { + struct irq_domain *domain = irq_get_handler_data(irq); + generic_handle_irq(irq_find_mapping(domain, __ffs(pending))); + } else { + spurious_interrupt(); + } +} + +asmlinkage void plat_irq_dispatch(void) +{ + unsigned long pending; + + pending = read_c0_status() & read_c0_cause() & ST0_IM; + + if (pending & STATUSF_IP7) + do_IRQ(RALINK_CPU_IRQ_COUNTER); + + else if (pending & STATUSF_IP5) + do_IRQ(RALINK_CPU_IRQ_FE); + + else if (pending & STATUSF_IP6) + do_IRQ(RALINK_CPU_IRQ_WIFI); + + else if (pending & STATUSF_IP4) + do_IRQ(RALINK_CPU_IRQ_PCI); + + else if (pending & STATUSF_IP2) + do_IRQ(RALINK_CPU_IRQ_INTC); + + else + spurious_interrupt(); +} + +static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) +{ + irq_set_chip_and_handler(irq, &ralink_intc_irq_chip, handle_level_irq); + + return 0; +} + +static const struct irq_domain_ops irq_domain_ops = { + .xlate = irq_domain_xlate_onecell, + .map = intc_map, +}; + +static int __init intc_of_init(struct device_node *node, + struct device_node *parent) +{ + struct resource res; + struct irq_domain *domain; + int irq; + + if (!of_property_read_u32_array(node, "ralink,intc-registers", + rt_intc_regs, 6)) + pr_info("intc: using register map from devicetree\n"); + + irq = irq_of_parse_and_map(node, 0); + if (!irq) + panic("Failed to get INTC IRQ"); + + if (of_address_to_resource(node, 0, &res)) + panic("Failed to get intc memory range"); + + if (request_mem_region(res.start, resource_size(&res), + res.name) < 0) + pr_err("Failed to request intc memory"); + + rt_intc_membase = ioremap_nocache(res.start, + resource_size(&res)); + if (!rt_intc_membase) + panic("Failed to remap intc memory"); + + /* disable all interrupts */ + rt_intc_w32(~0, INTC_REG_DISABLE); + + /* route all INTC interrupts to MIPS HW0 interrupt */ + rt_intc_w32(0, INTC_REG_TYPE); + + domain = irq_domain_add_legacy(node, RALINK_INTC_IRQ_COUNT, + RALINK_INTC_IRQ_BASE, 0, &irq_domain_ops, NULL); + if (!domain) + panic("Failed to add irqdomain"); + + rt_intc_w32(INTC_INT_GLOBAL, INTC_REG_ENABLE); + + irq_set_chained_handler(irq, ralink_intc_irq_handler); + irq_set_handler_data(irq, domain); + + /* tell the kernel which irq is used for performance monitoring */ + rt_perfcount_irq = irq_create_mapping(domain, 9); + + return 0; +} + +static struct of_device_id __initdata of_irq_ids[] = { + { .compatible = "mti,cpu-interrupt-controller", .data = mips_cpu_irq_of_init }, + { .compatible = "ralink,rt2880-intc", .data = intc_of_init }, + {}, +}; + +void __init arch_init_irq(void) +{ + of_irq_init(of_irq_ids); +} + |