diff options
Diffstat (limited to 'kernel/arch/powerpc/platforms/embedded6xx/hlwd-pic.c')
| -rw-r--r-- | kernel/arch/powerpc/platforms/embedded6xx/hlwd-pic.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/platforms/embedded6xx/hlwd-pic.c b/kernel/arch/powerpc/platforms/embedded6xx/hlwd-pic.c new file mode 100644 index 000000000..c269caee5 --- /dev/null +++ b/kernel/arch/powerpc/platforms/embedded6xx/hlwd-pic.c @@ -0,0 +1,236 @@ +/* + * arch/powerpc/platforms/embedded6xx/hlwd-pic.c + * + * Nintendo Wii "Hollywood" interrupt controller support. + * Copyright (C) 2009 The GameCube Linux Team + * Copyright (C) 2009 Albert Herranz + * + * 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. + * + */ +#define DRV_MODULE_NAME "hlwd-pic" +#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt + +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <asm/io.h> + +#include "hlwd-pic.h" + +#define HLWD_NR_IRQS 32 + +/* + * Each interrupt has a corresponding bit in both + * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers. + * + * Enabling/disabling an interrupt line involves asserting/clearing + * the corresponding bit in IMR. ACK'ing a request simply involves + * asserting the corresponding bit in ICR. + */ +#define HW_BROADWAY_ICR 0x00 +#define HW_BROADWAY_IMR 0x04 + + +/* + * IRQ chip hooks. + * + */ + +static void hlwd_pic_mask_and_ack(struct irq_data *d) +{ + int irq = irqd_to_hwirq(d); + void __iomem *io_base = irq_data_get_irq_chip_data(d); + u32 mask = 1 << irq; + + clrbits32(io_base + HW_BROADWAY_IMR, mask); + out_be32(io_base + HW_BROADWAY_ICR, mask); +} + +static void hlwd_pic_ack(struct irq_data *d) +{ + int irq = irqd_to_hwirq(d); + void __iomem *io_base = irq_data_get_irq_chip_data(d); + + out_be32(io_base + HW_BROADWAY_ICR, 1 << irq); +} + +static void hlwd_pic_mask(struct irq_data *d) +{ + int irq = irqd_to_hwirq(d); + void __iomem *io_base = irq_data_get_irq_chip_data(d); + + clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq); +} + +static void hlwd_pic_unmask(struct irq_data *d) +{ + int irq = irqd_to_hwirq(d); + void __iomem *io_base = irq_data_get_irq_chip_data(d); + + setbits32(io_base + HW_BROADWAY_IMR, 1 << irq); +} + + +static struct irq_chip hlwd_pic = { + .name = "hlwd-pic", + .irq_ack = hlwd_pic_ack, + .irq_mask_ack = hlwd_pic_mask_and_ack, + .irq_mask = hlwd_pic_mask, + .irq_unmask = hlwd_pic_unmask, +}; + +/* + * IRQ host hooks. + * + */ + +static struct irq_domain *hlwd_irq_host; + +static int hlwd_pic_map(struct irq_domain *h, unsigned int virq, + irq_hw_number_t hwirq) +{ + irq_set_chip_data(virq, h->host_data); + irq_set_status_flags(virq, IRQ_LEVEL); + irq_set_chip_and_handler(virq, &hlwd_pic, handle_level_irq); + return 0; +} + +static const struct irq_domain_ops hlwd_irq_domain_ops = { + .map = hlwd_pic_map, +}; + +static unsigned int __hlwd_pic_get_irq(struct irq_domain *h) +{ + void __iomem *io_base = h->host_data; + int irq; + u32 irq_status; + + irq_status = in_be32(io_base + HW_BROADWAY_ICR) & + in_be32(io_base + HW_BROADWAY_IMR); + if (irq_status == 0) + return NO_IRQ; /* no more IRQs pending */ + + irq = __ffs(irq_status); + return irq_linear_revmap(h, irq); +} + +static void hlwd_pic_irq_cascade(unsigned int cascade_virq, + struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct irq_domain *irq_domain = irq_get_handler_data(cascade_virq); + unsigned int virq; + + raw_spin_lock(&desc->lock); + chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */ + raw_spin_unlock(&desc->lock); + + virq = __hlwd_pic_get_irq(irq_domain); + if (virq != NO_IRQ) + generic_handle_irq(virq); + else + pr_err("spurious interrupt!\n"); + + raw_spin_lock(&desc->lock); + chip->irq_ack(&desc->irq_data); /* IRQ_LEVEL */ + if (!irqd_irq_disabled(&desc->irq_data) && chip->irq_unmask) + chip->irq_unmask(&desc->irq_data); + raw_spin_unlock(&desc->lock); +} + +/* + * Platform hooks. + * + */ + +static void __hlwd_quiesce(void __iomem *io_base) +{ + /* mask and ack all IRQs */ + out_be32(io_base + HW_BROADWAY_IMR, 0); + out_be32(io_base + HW_BROADWAY_ICR, 0xffffffff); +} + +struct irq_domain *hlwd_pic_init(struct device_node *np) +{ + struct irq_domain *irq_domain; + struct resource res; + void __iomem *io_base; + int retval; + + retval = of_address_to_resource(np, 0, &res); + if (retval) { + pr_err("no io memory range found\n"); + return NULL; + } + io_base = ioremap(res.start, resource_size(&res)); + if (!io_base) { + pr_err("ioremap failed\n"); + return NULL; + } + + pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base); + + __hlwd_quiesce(io_base); + + irq_domain = irq_domain_add_linear(np, HLWD_NR_IRQS, + &hlwd_irq_domain_ops, io_base); + if (!irq_domain) { + pr_err("failed to allocate irq_domain\n"); + iounmap(io_base); + return NULL; + } + + return irq_domain; +} + +unsigned int hlwd_pic_get_irq(void) +{ + return __hlwd_pic_get_irq(hlwd_irq_host); +} + +/* + * Probe function. + * + */ + +void hlwd_pic_probe(void) +{ + struct irq_domain *host; + struct device_node *np; + const u32 *interrupts; + int cascade_virq; + + for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") { + interrupts = of_get_property(np, "interrupts", NULL); + if (interrupts) { + host = hlwd_pic_init(np); + BUG_ON(!host); + cascade_virq = irq_of_parse_and_map(np, 0); + irq_set_handler_data(cascade_virq, host); + irq_set_chained_handler(cascade_virq, + hlwd_pic_irq_cascade); + hlwd_irq_host = host; + break; + } + } +} + +/** + * hlwd_quiesce() - quiesce hollywood irq controller + * + * Mask and ack all interrupt sources. + * + */ +void hlwd_quiesce(void) +{ + void __iomem *io_base = hlwd_irq_host->host_data; + + __hlwd_quiesce(io_base); +} + |