1/* irq-mb93493.c: MB93493 companion chip interrupt handler
2 *
3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/ptrace.h>
13#include <linux/errno.h>
14#include <linux/signal.h>
15#include <linux/sched.h>
16#include <linux/ioport.h>
17#include <linux/interrupt.h>
18#include <linux/init.h>
19#include <linux/irq.h>
20
21#include <asm/io.h>
22#include <asm/system.h>
23#include <asm/bitops.h>
24#include <asm/delay.h>
25#include <asm/irq.h>
26#include <asm/irc-regs.h>
27#include <asm/mb93493-irqs.h>
28#include <asm/mb93493-regs.h>
29
30#define IRQ_ROUTE_ONE(X) (X##_ROUTE << (X - IRQ_BASE_MB93493))
31
32#define IRQ_ROUTING					\
33	(IRQ_ROUTE_ONE(IRQ_MB93493_VDC)		|	\
34	 IRQ_ROUTE_ONE(IRQ_MB93493_VCC)		|	\
35	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_OUT)	|	\
36	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_0)	|	\
37	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_1)	|	\
38	 IRQ_ROUTE_ONE(IRQ_MB93493_USB)		|	\
39	 IRQ_ROUTE_ONE(IRQ_MB93493_LOCAL_BUS)	|	\
40	 IRQ_ROUTE_ONE(IRQ_MB93493_PCMCIA)	|	\
41	 IRQ_ROUTE_ONE(IRQ_MB93493_GPIO)	|	\
42	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_IN))
43
44/*
45 * daughter board PIC operations
46 * - there is no way to ACK interrupts in the MB93493 chip
47 */
48static void frv_mb93493_mask(unsigned int irq)
49{
50	uint32_t iqsr;
51	volatile void *piqsr;
52
53	if (IRQ_ROUTING & (1 << (irq - IRQ_BASE_MB93493)))
54		piqsr = __addr_MB93493_IQSR(1);
55	else
56		piqsr = __addr_MB93493_IQSR(0);
57
58	iqsr = readl(piqsr);
59	iqsr &= ~(1 << (irq - IRQ_BASE_MB93493 + 16));
60	writel(iqsr, piqsr);
61}
62
63static void frv_mb93493_ack(unsigned int irq)
64{
65}
66
67static void frv_mb93493_unmask(unsigned int irq)
68{
69	uint32_t iqsr;
70	volatile void *piqsr;
71
72	if (IRQ_ROUTING & (1 << (irq - IRQ_BASE_MB93493)))
73		piqsr = __addr_MB93493_IQSR(1);
74	else
75		piqsr = __addr_MB93493_IQSR(0);
76
77	iqsr = readl(piqsr);
78	iqsr |= 1 << (irq - IRQ_BASE_MB93493 + 16);
79	writel(iqsr, piqsr);
80}
81
82static struct irq_chip frv_mb93493_pic = {
83	.name		= "mb93093",
84	.ack		= frv_mb93493_ack,
85	.mask		= frv_mb93493_mask,
86	.mask_ack	= frv_mb93493_mask,
87	.unmask		= frv_mb93493_unmask,
88};
89
90/*
91 * MB93493 PIC interrupt handler
92 */
93static irqreturn_t mb93493_interrupt(int irq, void *_piqsr)
94{
95	volatile void *piqsr = _piqsr;
96	uint32_t iqsr;
97
98	iqsr = readl(piqsr);
99	iqsr = iqsr & (iqsr >> 16) & 0xffff;
100
101	/* poll all the triggered IRQs */
102	while (iqsr) {
103		int irq;
104
105		asm("scan %1,gr0,%0" : "=r"(irq) : "r"(iqsr));
106		irq = 31 - irq;
107		iqsr &= ~(1 << irq);
108
109		generic_handle_irq(IRQ_BASE_MB93493 + irq);
110	}
111
112	return IRQ_HANDLED;
113}
114
115/*
116 * define an interrupt action for each MB93493 PIC output
117 * - use dev_id to indicate the MB93493 PIC input to output mappings
118 */
119static struct irqaction mb93493_irq[2]  = {
120	[0] = {
121		.handler	= mb93493_interrupt,
122		.flags		= IRQF_DISABLED | IRQF_SHARED,
123		.mask		= CPU_MASK_NONE,
124		.name		= "mb93493.0",
125		.dev_id		= (void *) __addr_MB93493_IQSR(0),
126	},
127	[1] = {
128		.handler	= mb93493_interrupt,
129		.flags		= IRQF_DISABLED | IRQF_SHARED,
130		.mask		= CPU_MASK_NONE,
131		.name		= "mb93493.1",
132		.dev_id		= (void *) __addr_MB93493_IQSR(1),
133	}
134};
135
136/*
137 * initialise the motherboard MB93493's PIC
138 */
139void __init mb93493_init(void)
140{
141	int irq;
142
143	for (irq = IRQ_BASE_MB93493 + 0; irq <= IRQ_BASE_MB93493 + 10; irq++)
144		set_irq_chip_and_handler(irq, &frv_mb93493_pic, handle_edge_irq);
145
146	/* the MB93493 drives external IRQ inputs on the CPU PIC */
147	setup_irq(IRQ_CPU_MB93493_0, &mb93493_irq[0]);
148	setup_irq(IRQ_CPU_MB93493_1, &mb93493_irq[1]);
149}
150