diff options
Diffstat (limited to 'arch/powerpc/platforms/embedded6xx/flipper-pic.c')
| -rw-r--r-- | arch/powerpc/platforms/embedded6xx/flipper-pic.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/embedded6xx/flipper-pic.c b/arch/powerpc/platforms/embedded6xx/flipper-pic.c new file mode 100644 index 000000000..db0be007f --- /dev/null +++ b/arch/powerpc/platforms/embedded6xx/flipper-pic.c @@ -0,0 +1,248 @@ +/* + * arch/powerpc/platforms/embedded6xx/flipper-pic.c + * + * Nintendo GameCube/Wii "Flipper" interrupt controller support. + * Copyright (C) 2004-2009 The GameCube Linux Team + * Copyright (C) 2007,2008,2009 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 "flipper-pic" +#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/irq.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <asm/io.h> + +#include "flipper-pic.h" + +#define FLIPPER_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 setting/clearing + * the corresponding bit in IMR. + * Except for the RSW interrupt, all interrupts get deasserted automatically + * when the source deasserts the interrupt. + */ +#define FLIPPER_ICR 0x00 +#define FLIPPER_ICR_RSS (1<<16) /* reset switch state */ + +#define FLIPPER_IMR 0x04 + +#define FLIPPER_RESET 0x24 + + +/* + * IRQ chip hooks. + * + */ + +static void flipper_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 + FLIPPER_IMR, mask); + /* this is at least needed for RSW */ + out_be32(io_base + FLIPPER_ICR, mask); +} + +static void flipper_pic_ack(struct irq_data *d) +{ + int irq = irqd_to_hwirq(d); + void __iomem *io_base = irq_data_get_irq_chip_data(d); + + /* this is at least needed for RSW */ + out_be32(io_base + FLIPPER_ICR, 1 << irq); +} + +static void flipper_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 + FLIPPER_IMR, 1 << irq); +} + +static void flipper_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 + FLIPPER_IMR, 1 << irq); +} + + +static struct irq_chip flipper_pic = { + .name = "flipper-pic", + .irq_ack = flipper_pic_ack, + .irq_mask_ack = flipper_pic_mask_and_ack, + .irq_mask = flipper_pic_mask, + .irq_unmask = flipper_pic_unmask, +}; + +/* + * IRQ host hooks. + * + */ + +static struct irq_domain *flipper_irq_host; + +static int flipper_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, &flipper_pic, handle_level_irq); + return 0; +} + +static const struct irq_domain_ops flipper_irq_domain_ops = { + .map = flipper_pic_map, +}; + +/* + * Platform hooks. + * + */ + +static void __flipper_quiesce(void __iomem *io_base) +{ + /* mask and ack all IRQs */ + out_be32(io_base + FLIPPER_IMR, 0x00000000); + out_be32(io_base + FLIPPER_ICR, 0xffffffff); +} + +static struct irq_domain * __init flipper_pic_init(struct device_node *np) +{ + struct device_node *pi; + struct irq_domain *irq_domain = NULL; + struct resource res; + void __iomem *io_base; + int retval; + + pi = of_get_parent(np); + if (!pi) { + pr_err("no parent found\n"); + goto out; + } + if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) { + pr_err("unexpected parent compatible\n"); + goto out; + } + + retval = of_address_to_resource(pi, 0, &res); + if (retval) { + pr_err("no io memory range found\n"); + goto out; + } + io_base = ioremap(res.start, resource_size(&res)); + + pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base); + + __flipper_quiesce(io_base); + + irq_domain = irq_domain_add_linear(np, FLIPPER_NR_IRQS, + &flipper_irq_domain_ops, io_base); + if (!irq_domain) { + pr_err("failed to allocate irq_domain\n"); + return NULL; + } + +out: + return irq_domain; +} + +unsigned int flipper_pic_get_irq(void) +{ + void __iomem *io_base = flipper_irq_host->host_data; + int irq; + u32 irq_status; + + irq_status = in_be32(io_base + FLIPPER_ICR) & + in_be32(io_base + FLIPPER_IMR); + if (irq_status == 0) + return 0; /* no more IRQs pending */ + + irq = __ffs(irq_status); + return irq_linear_revmap(flipper_irq_host, irq); +} + +/* + * Probe function. + * + */ + +void __init flipper_pic_probe(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-pic"); + BUG_ON(!np); + + flipper_irq_host = flipper_pic_init(np); + BUG_ON(!flipper_irq_host); + + irq_set_default_host(flipper_irq_host); + + of_node_put(np); +} + +/* + * Misc functions related to the flipper chipset. + * + */ + +/** + * flipper_quiesce() - quiesce flipper irq controller + * + * Mask and ack all interrupt sources. + * + */ +void flipper_quiesce(void) +{ + void __iomem *io_base = flipper_irq_host->host_data; + + __flipper_quiesce(io_base); +} + +/* + * Resets the platform. + */ +void flipper_platform_reset(void) +{ + void __iomem *io_base; + + if (flipper_irq_host && flipper_irq_host->host_data) { + io_base = flipper_irq_host->host_data; + out_8(io_base + FLIPPER_RESET, 0x00); + } +} + +/* + * Returns non-zero if the reset button is pressed. + */ +int flipper_is_reset_button_pressed(void) +{ + void __iomem *io_base; + u32 icr; + + if (flipper_irq_host && flipper_irq_host->host_data) { + io_base = flipper_irq_host->host_data; + icr = in_be32(io_base + FLIPPER_ICR); + return !(icr & FLIPPER_ICR_RSS); + } + return 0; +} + |