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#include <linux/bitops.h>
 21
 22#include <asm/io.h>
 23#include <asm/delay.h>
 24#include <asm/irq.h>
 25#include <asm/irc-regs.h>
 26#include <asm/mb93493-irqs.h>
 27#include <asm/mb93493-regs.h>
 28
 29#define IRQ_ROUTE_ONE(X) (X##_ROUTE << (X - IRQ_BASE_MB93493))
 30
 31#define IRQ_ROUTING					\
 32	(IRQ_ROUTE_ONE(IRQ_MB93493_VDC)		|	\
 33	 IRQ_ROUTE_ONE(IRQ_MB93493_VCC)		|	\
 34	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_OUT)	|	\
 35	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_0)	|	\
 36	 IRQ_ROUTE_ONE(IRQ_MB93493_I2C_1)	|	\
 37	 IRQ_ROUTE_ONE(IRQ_MB93493_USB)		|	\
 38	 IRQ_ROUTE_ONE(IRQ_MB93493_LOCAL_BUS)	|	\
 39	 IRQ_ROUTE_ONE(IRQ_MB93493_PCMCIA)	|	\
 40	 IRQ_ROUTE_ONE(IRQ_MB93493_GPIO)	|	\
 41	 IRQ_ROUTE_ONE(IRQ_MB93493_AUDIO_IN))
 42
 43/*
 44 * daughter board PIC operations
 45 * - there is no way to ACK interrupts in the MB93493 chip
 46 */
 47static void frv_mb93493_mask(struct irq_data *d)
 48{
 49	uint32_t iqsr;
 50	volatile void *piqsr;
 51
 52	if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
 53		piqsr = __addr_MB93493_IQSR(1);
 54	else
 55		piqsr = __addr_MB93493_IQSR(0);
 56
 57	iqsr = readl(piqsr);
 58	iqsr &= ~(1 << (d->irq - IRQ_BASE_MB93493 + 16));
 59	writel(iqsr, piqsr);
 60}
 61
 62static void frv_mb93493_ack(struct irq_data *d)
 63{
 64}
 65
 66static void frv_mb93493_unmask(struct irq_data *d)
 67{
 68	uint32_t iqsr;
 69	volatile void *piqsr;
 70
 71	if (IRQ_ROUTING & (1 << (d->irq - IRQ_BASE_MB93493)))
 72		piqsr = __addr_MB93493_IQSR(1);
 73	else
 74		piqsr = __addr_MB93493_IQSR(0);
 75
 76	iqsr = readl(piqsr);
 77	iqsr |= 1 << (d->irq - IRQ_BASE_MB93493 + 16);
 78	writel(iqsr, piqsr);
 79}
 80
 81static struct irq_chip frv_mb93493_pic = {
 82	.name		= "mb93093",
 83	.irq_ack	= frv_mb93493_ack,
 84	.irq_mask	= frv_mb93493_mask,
 85	.irq_mask_ack	= frv_mb93493_mask,
 86	.irq_unmask	= frv_mb93493_unmask,
 87};
 88
 89/*
 90 * MB93493 PIC interrupt handler
 91 */
 92static irqreturn_t mb93493_interrupt(int irq, void *_piqsr)
 93{
 94	volatile void *piqsr = _piqsr;
 95	uint32_t iqsr;
 96
 97	iqsr = readl(piqsr);
 98	iqsr = iqsr & (iqsr >> 16) & 0xffff;
 99
100	/* poll all the triggered IRQs */
101	while (iqsr) {
102		int irq;
103
104		asm("scan %1,gr0,%0" : "=r"(irq) : "r"(iqsr));
105		irq = 31 - irq;
106		iqsr &= ~(1 << irq);
107
108		generic_handle_irq(IRQ_BASE_MB93493 + irq);
109	}
110
111	return IRQ_HANDLED;
112}
113
114/*
115 * define an interrupt action for each MB93493 PIC output
116 * - use dev_id to indicate the MB93493 PIC input to output mappings
117 */
118static struct irqaction mb93493_irq[2]  = {
119	[0] = {
120		.handler	= mb93493_interrupt,
121		.flags		= IRQF_DISABLED | IRQF_SHARED,
122		.name		= "mb93493.0",
123		.dev_id		= (void *) __addr_MB93493_IQSR(0),
124	},
125	[1] = {
126		.handler	= mb93493_interrupt,
127		.flags		= IRQF_DISABLED | IRQF_SHARED,
128		.name		= "mb93493.1",
129		.dev_id		= (void *) __addr_MB93493_IQSR(1),
130	}
131};
132
133/*
134 * initialise the motherboard MB93493's PIC
135 */
136void __init mb93493_init(void)
137{
138	int irq;
139
140	for (irq = IRQ_BASE_MB93493 + 0; irq <= IRQ_BASE_MB93493 + 10; irq++)
141		irq_set_chip_and_handler(irq, &frv_mb93493_pic,
142					 handle_edge_irq);
143
144	/* the MB93493 drives external IRQ inputs on the CPU PIC */
145	setup_irq(IRQ_CPU_MB93493_0, &mb93493_irq[0]);
146	setup_irq(IRQ_CPU_MB93493_1, &mb93493_irq[1]);
147}