Add linux-next specific files for 20110831
[linux-2.6/next.git] / arch / powerpc / platforms / embedded6xx / flipper-pic.c
blobf61a2dd96b9972638411b3bf1bf2e790178bb60f
1 /*
2 * arch/powerpc/platforms/embedded6xx/flipper-pic.c
4 * Nintendo GameCube/Wii "Flipper" interrupt controller support.
5 * Copyright (C) 2004-2009 The GameCube Linux Team
6 * Copyright (C) 2007,2008,2009 Albert Herranz
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
14 #define DRV_MODULE_NAME "flipper-pic"
15 #define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/irq.h>
20 #include <linux/of.h>
21 #include <asm/io.h>
23 #include "flipper-pic.h"
25 #define FLIPPER_NR_IRQS 32
28 * Each interrupt has a corresponding bit in both
29 * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
31 * Enabling/disabling an interrupt line involves setting/clearing
32 * the corresponding bit in IMR.
33 * Except for the RSW interrupt, all interrupts get deasserted automatically
34 * when the source deasserts the interrupt.
36 #define FLIPPER_ICR 0x00
37 #define FLIPPER_ICR_RSS (1<<16) /* reset switch state */
39 #define FLIPPER_IMR 0x04
41 #define FLIPPER_RESET 0x24
45 * IRQ chip hooks.
49 static void flipper_pic_mask_and_ack(struct irq_data *d)
51 int irq = irqd_to_hwirq(d);
52 void __iomem *io_base = irq_data_get_irq_chip_data(d);
53 u32 mask = 1 << irq;
55 clrbits32(io_base + FLIPPER_IMR, mask);
56 /* this is at least needed for RSW */
57 out_be32(io_base + FLIPPER_ICR, mask);
60 static void flipper_pic_ack(struct irq_data *d)
62 int irq = irqd_to_hwirq(d);
63 void __iomem *io_base = irq_data_get_irq_chip_data(d);
65 /* this is at least needed for RSW */
66 out_be32(io_base + FLIPPER_ICR, 1 << irq);
69 static void flipper_pic_mask(struct irq_data *d)
71 int irq = irqd_to_hwirq(d);
72 void __iomem *io_base = irq_data_get_irq_chip_data(d);
74 clrbits32(io_base + FLIPPER_IMR, 1 << irq);
77 static void flipper_pic_unmask(struct irq_data *d)
79 int irq = irqd_to_hwirq(d);
80 void __iomem *io_base = irq_data_get_irq_chip_data(d);
82 setbits32(io_base + FLIPPER_IMR, 1 << irq);
86 static struct irq_chip flipper_pic = {
87 .name = "flipper-pic",
88 .irq_ack = flipper_pic_ack,
89 .irq_mask_ack = flipper_pic_mask_and_ack,
90 .irq_mask = flipper_pic_mask,
91 .irq_unmask = flipper_pic_unmask,
95 * IRQ host hooks.
99 static struct irq_host *flipper_irq_host;
101 static int flipper_pic_map(struct irq_host *h, unsigned int virq,
102 irq_hw_number_t hwirq)
104 irq_set_chip_data(virq, h->host_data);
105 irq_set_status_flags(virq, IRQ_LEVEL);
106 irq_set_chip_and_handler(virq, &flipper_pic, handle_level_irq);
107 return 0;
110 static int flipper_pic_match(struct irq_host *h, struct device_node *np)
112 return 1;
116 static struct irq_host_ops flipper_irq_host_ops = {
117 .map = flipper_pic_map,
118 .match = flipper_pic_match,
122 * Platform hooks.
126 static void __flipper_quiesce(void __iomem *io_base)
128 /* mask and ack all IRQs */
129 out_be32(io_base + FLIPPER_IMR, 0x00000000);
130 out_be32(io_base + FLIPPER_ICR, 0xffffffff);
133 struct irq_host * __init flipper_pic_init(struct device_node *np)
135 struct device_node *pi;
136 struct irq_host *irq_host = NULL;
137 struct resource res;
138 void __iomem *io_base;
139 int retval;
141 pi = of_get_parent(np);
142 if (!pi) {
143 pr_err("no parent found\n");
144 goto out;
146 if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) {
147 pr_err("unexpected parent compatible\n");
148 goto out;
151 retval = of_address_to_resource(pi, 0, &res);
152 if (retval) {
153 pr_err("no io memory range found\n");
154 goto out;
156 io_base = ioremap(res.start, resource_size(&res));
158 pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
160 __flipper_quiesce(io_base);
162 irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, FLIPPER_NR_IRQS,
163 &flipper_irq_host_ops, -1);
164 if (!irq_host) {
165 pr_err("failed to allocate irq_host\n");
166 return NULL;
169 irq_host->host_data = io_base;
171 out:
172 return irq_host;
175 unsigned int flipper_pic_get_irq(void)
177 void __iomem *io_base = flipper_irq_host->host_data;
178 int irq;
179 u32 irq_status;
181 irq_status = in_be32(io_base + FLIPPER_ICR) &
182 in_be32(io_base + FLIPPER_IMR);
183 if (irq_status == 0)
184 return NO_IRQ; /* no more IRQs pending */
186 irq = __ffs(irq_status);
187 return irq_linear_revmap(flipper_irq_host, irq);
191 * Probe function.
195 void __init flipper_pic_probe(void)
197 struct device_node *np;
199 np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-pic");
200 BUG_ON(!np);
202 flipper_irq_host = flipper_pic_init(np);
203 BUG_ON(!flipper_irq_host);
205 irq_set_default_host(flipper_irq_host);
207 of_node_put(np);
211 * Misc functions related to the flipper chipset.
216 * flipper_quiesce() - quiesce flipper irq controller
218 * Mask and ack all interrupt sources.
221 void flipper_quiesce(void)
223 void __iomem *io_base = flipper_irq_host->host_data;
225 __flipper_quiesce(io_base);
229 * Resets the platform.
231 void flipper_platform_reset(void)
233 void __iomem *io_base;
235 if (flipper_irq_host && flipper_irq_host->host_data) {
236 io_base = flipper_irq_host->host_data;
237 out_8(io_base + FLIPPER_RESET, 0x00);
242 * Returns non-zero if the reset button is pressed.
244 int flipper_is_reset_button_pressed(void)
246 void __iomem *io_base;
247 u32 icr;
249 if (flipper_irq_host && flipper_irq_host->host_data) {
250 io_base = flipper_irq_host->host_data;
251 icr = in_be32(io_base + FLIPPER_ICR);
252 return !(icr & FLIPPER_ICR_RSS);
254 return 0;