diff options
Diffstat (limited to 'kernel/arch/mips/lantiq/irq.c')
| -rw-r--r-- | kernel/arch/mips/lantiq/irq.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/kernel/arch/mips/lantiq/irq.c b/kernel/arch/mips/lantiq/irq.c new file mode 100644 index 000000000..6ab105734 --- /dev/null +++ b/kernel/arch/mips/lantiq/irq.c @@ -0,0 +1,483 @@ +/* + * 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) 2010 John Crispin <blogic@openwrt.org> + * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com> + */ + +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/sched.h> +#include <linux/irqdomain.h> +#include <linux/of_platform.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/bootinfo.h> +#include <asm/irq_cpu.h> + +#include <lantiq_soc.h> +#include <irq.h> + +/* register definitions - internal irqs */ +#define LTQ_ICU_IM0_ISR 0x0000 +#define LTQ_ICU_IM0_IER 0x0008 +#define LTQ_ICU_IM0_IOSR 0x0010 +#define LTQ_ICU_IM0_IRSR 0x0018 +#define LTQ_ICU_IM0_IMR 0x0020 +#define LTQ_ICU_IM1_ISR 0x0028 +#define LTQ_ICU_OFFSET (LTQ_ICU_IM1_ISR - LTQ_ICU_IM0_ISR) + +/* register definitions - external irqs */ +#define LTQ_EIU_EXIN_C 0x0000 +#define LTQ_EIU_EXIN_INIC 0x0004 +#define LTQ_EIU_EXIN_INC 0x0008 +#define LTQ_EIU_EXIN_INEN 0x000C + +/* number of external interrupts */ +#define MAX_EIU 6 + +/* the performance counter */ +#define LTQ_PERF_IRQ (INT_NUM_IM4_IRL0 + 31) + +/* + * irqs generated by devices attached to the EBU need to be acked in + * a special manner + */ +#define LTQ_ICU_EBU_IRQ 22 + +#define ltq_icu_w32(m, x, y) ltq_w32((x), ltq_icu_membase[m] + (y)) +#define ltq_icu_r32(m, x) ltq_r32(ltq_icu_membase[m] + (x)) + +#define ltq_eiu_w32(x, y) ltq_w32((x), ltq_eiu_membase + (y)) +#define ltq_eiu_r32(x) ltq_r32(ltq_eiu_membase + (x)) + +/* our 2 ipi interrupts for VSMP */ +#define MIPS_CPU_IPI_RESCHED_IRQ 0 +#define MIPS_CPU_IPI_CALL_IRQ 1 + +/* we have a cascade of 8 irqs */ +#define MIPS_CPU_IRQ_CASCADE 8 + +#ifdef CONFIG_MIPS_MT_SMP +int gic_present; +#endif + +static int exin_avail; +static struct resource ltq_eiu_irq[MAX_EIU]; +static void __iomem *ltq_icu_membase[MAX_IM]; +static void __iomem *ltq_eiu_membase; +static struct irq_domain *ltq_domain; +static int ltq_perfcount_irq; + +int ltq_eiu_get_irq(int exin) +{ + if (exin < exin_avail) + return ltq_eiu_irq[exin].start; + return -1; +} + +void ltq_disable_irq(struct irq_data *d) +{ + u32 ier = LTQ_ICU_IM0_IER; + int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; + int im = offset / INT_NUM_IM_OFFSET; + + offset %= INT_NUM_IM_OFFSET; + ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier); +} + +void ltq_mask_and_ack_irq(struct irq_data *d) +{ + u32 ier = LTQ_ICU_IM0_IER; + u32 isr = LTQ_ICU_IM0_ISR; + int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; + int im = offset / INT_NUM_IM_OFFSET; + + offset %= INT_NUM_IM_OFFSET; + ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier); + ltq_icu_w32(im, BIT(offset), isr); +} + +static void ltq_ack_irq(struct irq_data *d) +{ + u32 isr = LTQ_ICU_IM0_ISR; + int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; + int im = offset / INT_NUM_IM_OFFSET; + + offset %= INT_NUM_IM_OFFSET; + ltq_icu_w32(im, BIT(offset), isr); +} + +void ltq_enable_irq(struct irq_data *d) +{ + u32 ier = LTQ_ICU_IM0_IER; + int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; + int im = offset / INT_NUM_IM_OFFSET; + + offset %= INT_NUM_IM_OFFSET; + ltq_icu_w32(im, ltq_icu_r32(im, ier) | BIT(offset), ier); +} + +static int ltq_eiu_settype(struct irq_data *d, unsigned int type) +{ + int i; + + for (i = 0; i < MAX_EIU; i++) { + if (d->hwirq == ltq_eiu_irq[i].start) { + int val = 0; + int edge = 0; + + switch (type) { + case IRQF_TRIGGER_NONE: + break; + case IRQF_TRIGGER_RISING: + val = 1; + edge = 1; + break; + case IRQF_TRIGGER_FALLING: + val = 2; + edge = 1; + break; + case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING: + val = 3; + edge = 1; + break; + case IRQF_TRIGGER_HIGH: + val = 5; + break; + case IRQF_TRIGGER_LOW: + val = 6; + break; + default: + pr_err("invalid type %d for irq %ld\n", + type, d->hwirq); + return -EINVAL; + } + + if (edge) + irq_set_handler(d->hwirq, handle_edge_irq); + + ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) | + (val << (i * 4)), LTQ_EIU_EXIN_C); + } + } + + return 0; +} + +static unsigned int ltq_startup_eiu_irq(struct irq_data *d) +{ + int i; + + ltq_enable_irq(d); + for (i = 0; i < MAX_EIU; i++) { + if (d->hwirq == ltq_eiu_irq[i].start) { + /* by default we are low level triggered */ + ltq_eiu_settype(d, IRQF_TRIGGER_LOW); + /* clear all pending */ + ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i), + LTQ_EIU_EXIN_INC); + /* enable */ + ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i), + LTQ_EIU_EXIN_INEN); + break; + } + } + + return 0; +} + +static void ltq_shutdown_eiu_irq(struct irq_data *d) +{ + int i; + + ltq_disable_irq(d); + for (i = 0; i < MAX_EIU; i++) { + if (d->hwirq == ltq_eiu_irq[i].start) { + /* disable */ + ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i), + LTQ_EIU_EXIN_INEN); + break; + } + } +} + +static struct irq_chip ltq_irq_type = { + "icu", + .irq_enable = ltq_enable_irq, + .irq_disable = ltq_disable_irq, + .irq_unmask = ltq_enable_irq, + .irq_ack = ltq_ack_irq, + .irq_mask = ltq_disable_irq, + .irq_mask_ack = ltq_mask_and_ack_irq, +}; + +static struct irq_chip ltq_eiu_type = { + "eiu", + .irq_startup = ltq_startup_eiu_irq, + .irq_shutdown = ltq_shutdown_eiu_irq, + .irq_enable = ltq_enable_irq, + .irq_disable = ltq_disable_irq, + .irq_unmask = ltq_enable_irq, + .irq_ack = ltq_ack_irq, + .irq_mask = ltq_disable_irq, + .irq_mask_ack = ltq_mask_and_ack_irq, + .irq_set_type = ltq_eiu_settype, +}; + +static void ltq_hw_irqdispatch(int module) +{ + u32 irq; + + irq = ltq_icu_r32(module, LTQ_ICU_IM0_IOSR); + if (irq == 0) + return; + + /* + * silicon bug causes only the msb set to 1 to be valid. all + * other bits might be bogus + */ + irq = __fls(irq); + do_IRQ((int)irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module)); + + /* if this is a EBU irq, we need to ack it or get a deadlock */ + if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT) + ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10, + LTQ_EBU_PCC_ISTAT); +} + +#define DEFINE_HWx_IRQDISPATCH(x) \ + static void ltq_hw ## x ## _irqdispatch(void) \ + { \ + ltq_hw_irqdispatch(x); \ + } +DEFINE_HWx_IRQDISPATCH(0) +DEFINE_HWx_IRQDISPATCH(1) +DEFINE_HWx_IRQDISPATCH(2) +DEFINE_HWx_IRQDISPATCH(3) +DEFINE_HWx_IRQDISPATCH(4) + +#if MIPS_CPU_TIMER_IRQ == 7 +static void ltq_hw5_irqdispatch(void) +{ + do_IRQ(MIPS_CPU_TIMER_IRQ); +} +#else +DEFINE_HWx_IRQDISPATCH(5) +#endif + +#ifdef CONFIG_MIPS_MT_SMP +void __init arch_init_ipiirq(int irq, struct irqaction *action) +{ + setup_irq(irq, action); + irq_set_handler(irq, handle_percpu_irq); +} + +static void ltq_sw0_irqdispatch(void) +{ + do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ); +} + +static void ltq_sw1_irqdispatch(void) +{ + do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ); +} +static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id) +{ + scheduler_ipi(); + return IRQ_HANDLED; +} + +static irqreturn_t ipi_call_interrupt(int irq, void *dev_id) +{ + smp_call_function_interrupt(); + return IRQ_HANDLED; +} + +static struct irqaction irq_resched = { + .handler = ipi_resched_interrupt, + .flags = IRQF_PERCPU, + .name = "IPI_resched" +}; + +static struct irqaction irq_call = { + .handler = ipi_call_interrupt, + .flags = IRQF_PERCPU, + .name = "IPI_call" +}; +#endif + +asmlinkage void plat_irq_dispatch(void) +{ + unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM; + unsigned int i; + + if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) { + do_IRQ(MIPS_CPU_TIMER_IRQ); + goto out; + } else { + for (i = 0; i < MAX_IM; i++) { + if (pending & (CAUSEF_IP2 << i)) { + ltq_hw_irqdispatch(i); + goto out; + } + } + } + pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status()); + +out: + return; +} + +static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) +{ + struct irq_chip *chip = <q_irq_type; + int i; + + if (hw < MIPS_CPU_IRQ_CASCADE) + return 0; + + for (i = 0; i < exin_avail; i++) + if (hw == ltq_eiu_irq[i].start) + chip = <q_eiu_type; + + irq_set_chip_and_handler(hw, chip, handle_level_irq); + + return 0; +} + +static const struct irq_domain_ops irq_domain_ops = { + .xlate = irq_domain_xlate_onetwocell, + .map = icu_map, +}; + +static struct irqaction cascade = { + .handler = no_action, + .name = "cascade", +}; + +int __init icu_of_init(struct device_node *node, struct device_node *parent) +{ + struct device_node *eiu_node; + struct resource res; + int i, ret; + + for (i = 0; i < MAX_IM; i++) { + if (of_address_to_resource(node, i, &res)) + panic("Failed to get icu memory range"); + + if (request_mem_region(res.start, resource_size(&res), + res.name) < 0) + pr_err("Failed to request icu memory"); + + ltq_icu_membase[i] = ioremap_nocache(res.start, + resource_size(&res)); + if (!ltq_icu_membase[i]) + panic("Failed to remap icu memory"); + } + + /* turn off all irqs by default */ + for (i = 0; i < MAX_IM; i++) { + /* make sure all irqs are turned off by default */ + ltq_icu_w32(i, 0, LTQ_ICU_IM0_IER); + /* clear all possibly pending interrupts */ + ltq_icu_w32(i, ~0, LTQ_ICU_IM0_ISR); + } + + mips_cpu_irq_init(); + + for (i = 0; i < MAX_IM; i++) + setup_irq(i + 2, &cascade); + + if (cpu_has_vint) { + pr_info("Setting up vectored interrupts\n"); + set_vi_handler(2, ltq_hw0_irqdispatch); + set_vi_handler(3, ltq_hw1_irqdispatch); + set_vi_handler(4, ltq_hw2_irqdispatch); + set_vi_handler(5, ltq_hw3_irqdispatch); + set_vi_handler(6, ltq_hw4_irqdispatch); + set_vi_handler(7, ltq_hw5_irqdispatch); + } + + ltq_domain = irq_domain_add_linear(node, + (MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE, + &irq_domain_ops, 0); + +#if defined(CONFIG_MIPS_MT_SMP) + if (cpu_has_vint) { + pr_info("Setting up IPI vectored interrupts\n"); + set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ltq_sw0_irqdispatch); + set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ltq_sw1_irqdispatch); + } + arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ, + &irq_resched); + arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ, &irq_call); +#endif + +#ifndef CONFIG_MIPS_MT_SMP + set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | + IE_IRQ3 | IE_IRQ4 | IE_IRQ5); +#else + set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 | + IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5); +#endif + + /* tell oprofile which irq to use */ + ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ); + + /* + * if the timer irq is not one of the mips irqs we need to + * create a mapping + */ + if (MIPS_CPU_TIMER_IRQ != 7) + irq_create_mapping(ltq_domain, MIPS_CPU_TIMER_IRQ); + + /* the external interrupts are optional and xway only */ + eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway"); + if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) { + /* find out how many external irq sources we have */ + exin_avail = of_irq_count(eiu_node); + + if (exin_avail > MAX_EIU) + exin_avail = MAX_EIU; + + ret = of_irq_to_resource_table(eiu_node, + ltq_eiu_irq, exin_avail); + if (ret != exin_avail) + panic("failed to load external irq resources"); + + if (request_mem_region(res.start, resource_size(&res), + res.name) < 0) + pr_err("Failed to request eiu memory"); + + ltq_eiu_membase = ioremap_nocache(res.start, + resource_size(&res)); + if (!ltq_eiu_membase) + panic("Failed to remap eiu memory"); + } + + return 0; +} + +int get_c0_perfcount_int(void) +{ + return ltq_perfcount_irq; +} + +unsigned int get_c0_compare_int(void) +{ + return MIPS_CPU_TIMER_IRQ; +} + +static struct of_device_id __initdata of_irq_ids[] = { + { .compatible = "lantiq,icu", .data = icu_of_init }, + {}, +}; + +void __init arch_init_irq(void) +{ + of_irq_init(of_irq_ids); +} |