diff options
Diffstat (limited to 'arch/openrisc/kernel')
| -rw-r--r-- | arch/openrisc/kernel/irq.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/openrisc/kernel/irq.c b/arch/openrisc/kernel/irq.c new file mode 100644 index 0000000..59b3023 --- /dev/null +++ b/arch/openrisc/kernel/irq.c @@ -0,0 +1,172 @@ +/* + * OpenRISC irq.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/ptrace.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/ftrace.h> +#include <linux/irq.h> +#include <linux/seq_file.h> +#include <linux/kernel_stat.h> + +#include <linux/irqflags.h> + +/* read interrupt enabled status */ +unsigned long arch_local_save_flags(void) +{ + return mfspr(SPR_SR) & (SPR_SR_IEE|SPR_SR_TEE); +} +EXPORT_SYMBOL(arch_local_save_flags); + +/* set interrupt enabled status */ +void arch_local_irq_restore(unsigned long flags) +{ + mtspr(SPR_SR, ((mfspr(SPR_SR) & ~(SPR_SR_IEE|SPR_SR_TEE)) | flags)); +} +EXPORT_SYMBOL(arch_local_irq_restore); + + +/* OR1K PIC implementation */ + +/* We're a couple of cycles faster than the generic implementations with + * these 'fast' versions. + */ + +static void or1k_pic_mask(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->irq)); +} + +static void or1k_pic_unmask(struct irq_data *data) +{ + mtspr(SPR_PICMR, mfspr(SPR_PICMR) | (1UL << data->irq)); +} + +static void or1k_pic_ack(struct irq_data *data) +{ + /* EDGE-triggered interrupts need to be ack'ed in order to clear + * the latch. + * LEVER-triggered interrupts do not need to be ack'ed; however, + * ack'ing the interrupt has no ill-effect and is quicker than + * trying to figure out what type it is... + */ + + /* The OpenRISC 1000 spec says to write a 1 to the bit to ack the + * interrupt, but the OR1200 does this backwards and requires a 0 + * to be written... + */ + +#ifdef CONFIG_OR1K_1200 + /* There are two oddities with the OR1200 PIC implementation: + * i) LEVEL-triggered interrupts are latched and need to be cleared + * ii) the interrupt latch is cleared by writing a 0 to the bit, + * as opposed to a 1 as mandated by the spec + */ + + mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->irq)); +#else + WARN(1, "Interrupt handling possibily broken\n"); + mtspr(SPR_PICSR, (1UL << irq)); +#endif +} + +static void or1k_pic_mask_ack(struct irq_data *data) +{ + /* Comments for pic_ack apply here, too */ + +#ifdef CONFIG_OR1K_1200 + mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->irq)); +#else + WARN(1, "Interrupt handling possibily broken\n"); + mtspr(SPR_PICSR, (1UL << irq)); +#endif +} + +static int or1k_pic_set_type(struct irq_data *data, unsigned int flow_type) +{ + /* There's nothing to do in the PIC configuration when changing + * flow type. Level and edge-triggered interrupts are both + * supported, but it's PIC-implementation specific which type + * is handled. */ + + return irq_setup_alt_chip(data, flow_type); +} + +static inline int pic_get_irq(int first) +{ + int irq; + + irq = ffs(mfspr(SPR_PICSR) >> first); + + return irq ? irq + first - 1 : NO_IRQ; +} + +static void __init or1k_irq_init(void) +{ + struct irq_chip_generic *gc; + struct irq_chip_type *ct; + + /* Disable all interrupts until explicitly requested */ + mtspr(SPR_PICMR, (0UL)); + + gc = irq_alloc_generic_chip("or1k-PIC", 1, 0, 0, handle_level_irq); + ct = gc->chip_types; + + ct->chip.irq_unmask = or1k_pic_unmask; + ct->chip.irq_mask = or1k_pic_mask; + ct->chip.irq_ack = or1k_pic_ack; + ct->chip.irq_mask_ack = or1k_pic_mask_ack; + ct->chip.irq_set_type = or1k_pic_set_type; + + /* The OR1K PIC can handle both level and edge trigged + * interrupts in roughly the same manner + */ +#if 0 + /* FIXME: chip.type??? */ + ct->chip.type = IRQ_TYPE_EDGE_BOTH | IRQ_TYPE_LEVEL_MASK; +#endif + + irq_setup_generic_chip(gc, IRQ_MSK(NR_IRQS), 0, + IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE); +} + +void __init init_IRQ(void) +{ + or1k_irq_init(); +} + +void __irq_entry do_IRQ(struct pt_regs *regs) +{ + int irq = -1; + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); + + while ((irq = pic_get_irq(irq + 1)) != NO_IRQ) + generic_handle_irq(irq); + + irq_exit(); + set_irq_regs(old_regs); +} + +unsigned int irq_create_of_mapping(struct device_node *controller, + const u32 *intspec, unsigned int intsize) +{ + return intspec[0]; +} +EXPORT_SYMBOL_GPL(irq_create_of_mapping); |
