diff options
Diffstat (limited to 'drivers/irqchip/irq-zevio.c')
| -rw-r--r-- | drivers/irqchip/irq-zevio.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-zevio.c b/drivers/irqchip/irq-zevio.c new file mode 100644 index 000000000000..8ed04c4a43ee --- /dev/null +++ b/drivers/irqchip/irq-zevio.c @@ -0,0 +1,127 @@ +/* + * linux/drivers/irqchip/irq-zevio.c + * + * Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au> + * + * 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. + * + */ + +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/mach/irq.h> +#include <asm/exception.h> + +#include "irqchip.h" + +#define IO_STATUS 0x000 +#define IO_RAW_STATUS 0x004 +#define IO_ENABLE 0x008 +#define IO_DISABLE 0x00C +#define IO_CURRENT 0x020 +#define IO_RESET 0x028 +#define IO_MAX_PRIOTY 0x02C + +#define IO_IRQ_BASE 0x000 +#define IO_FIQ_BASE 0x100 + +#define IO_INVERT_SEL 0x200 +#define IO_STICKY_SEL 0x204 +#define IO_PRIORITY_SEL 0x300 + +#define MAX_INTRS 32 +#define FIQ_START MAX_INTRS + +static struct irq_domain *zevio_irq_domain; +static void __iomem *zevio_irq_io; + +static void zevio_irq_ack(struct irq_data *irqd) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd); + struct irq_chip_regs *regs = + &container_of(irqd->chip, struct irq_chip_type, chip)->regs; + + readl(gc->reg_base + regs->ack); +} + +static asmlinkage void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs) +{ + int irqnr; + + while (readl(zevio_irq_io + IO_STATUS)) { + irqnr = readl(zevio_irq_io + IO_CURRENT); + irqnr = irq_find_mapping(zevio_irq_domain, irqnr); + handle_IRQ(irqnr, regs); + }; +} + +static void __init zevio_init_irq_base(void __iomem *base) +{ + /* Disable all interrupts */ + writel(~0, base + IO_DISABLE); + + /* Accept interrupts of all priorities */ + writel(0xF, base + IO_MAX_PRIOTY); + + /* Reset existing interrupts */ + readl(base + IO_RESET); +} + +static int __init zevio_of_init(struct device_node *node, + struct device_node *parent) +{ + unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; + struct irq_chip_generic *gc; + int ret; + + if (WARN_ON(zevio_irq_io || zevio_irq_domain)) + return -EBUSY; + + zevio_irq_io = of_iomap(node, 0); + BUG_ON(!zevio_irq_io); + + /* Do not invert interrupt status bits */ + writel(~0, zevio_irq_io + IO_INVERT_SEL); + + /* Disable sticky interrupts */ + writel(0, zevio_irq_io + IO_STICKY_SEL); + + /* We don't use IRQ priorities. Set each IRQ to highest priority. */ + memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32)); + + /* Init IRQ and FIQ */ + zevio_init_irq_base(zevio_irq_io + IO_IRQ_BASE); + zevio_init_irq_base(zevio_irq_io + IO_FIQ_BASE); + + zevio_irq_domain = irq_domain_add_linear(node, MAX_INTRS, + &irq_generic_chip_ops, NULL); + BUG_ON(!zevio_irq_domain); + + ret = irq_alloc_domain_generic_chips(zevio_irq_domain, MAX_INTRS, 1, + "zevio_intc", handle_level_irq, + clr, 0, IRQ_GC_INIT_MASK_CACHE); + BUG_ON(ret); + + gc = irq_get_domain_generic_chip(zevio_irq_domain, 0); + gc->reg_base = zevio_irq_io; + gc->chip_types[0].chip.irq_ack = zevio_irq_ack; + gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg; + gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg; + gc->chip_types[0].regs.mask = IO_IRQ_BASE + IO_ENABLE; + gc->chip_types[0].regs.enable = IO_IRQ_BASE + IO_ENABLE; + gc->chip_types[0].regs.disable = IO_IRQ_BASE + IO_DISABLE; + gc->chip_types[0].regs.ack = IO_IRQ_BASE + IO_RESET; + + set_handle_irq(zevio_handle_irq); + + pr_info("TI-NSPIRE classic IRQ controller\n"); + return 0; +} + +IRQCHIP_DECLARE(zevio_irq, "lsi,zevio-intc", zevio_of_init); |