/arch/sh/boards/mach-cayman/irq.c

  1/*
  2 * arch/sh/mach-cayman/irq.c - SH-5 Cayman Interrupt Support
  3 *
  4 * This file handles the board specific parts of the Cayman interrupt system
  5 *
  6 * Copyright (C) 2002 Stuart Menefy
  7 *
  8 * This file is subject to the terms and conditions of the GNU General Public
  9 * License.  See the file "COPYING" in the main directory of this archive
 10 * for more details.
 11 */
 12#include <linux/io.h>
 13#include <linux/irq.h>
 14#include <linux/interrupt.h>
 15#include <linux/signal.h>
 16#include <cpu/irq.h>
 17#include <asm/page.h>
 18
 19/* Setup for the SMSC FDC37C935 / LAN91C100FD */
 20#define SMSC_IRQ         IRQ_IRL1
 21
 22/* Setup for PCI Bus 2, which transmits interrupts via the EPLD */
 23#define PCI2_IRQ         IRQ_IRL3
 24
 25unsigned long epld_virt;
 26
 27#define EPLD_BASE        0x04002000
 28#define EPLD_STATUS_BASE (epld_virt + 0x10)
 29#define EPLD_MASK_BASE   (epld_virt + 0x20)
 30
 31/* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto
 32   the same SH-5 interrupt */
 33
 34static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id)
 35{
 36        printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
 37	return IRQ_NONE;
 38}
 39
 40static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id)
 41{
 42        printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq);
 43	return IRQ_NONE;
 44}
 45
 46static struct irqaction cayman_action_smsc = {
 47	.name		= "Cayman SMSC Mux",
 48	.handler	= cayman_interrupt_smsc,
 49	.flags		= IRQF_DISABLED,
 50};
 51
 52static struct irqaction cayman_action_pci2 = {
 53	.name		= "Cayman PCI2 Mux",
 54	.handler	= cayman_interrupt_pci2,
 55	.flags		= IRQF_DISABLED,
 56};
 57
 58static void enable_cayman_irq(unsigned int irq)
 59{
 60	unsigned long flags;
 61	unsigned long mask;
 62	unsigned int reg;
 63	unsigned char bit;
 64
 65	irq -= START_EXT_IRQS;
 66	reg = EPLD_MASK_BASE + ((irq / 8) << 2);
 67	bit = 1<<(irq % 8);
 68	local_irq_save(flags);
 69	mask = __raw_readl(reg);
 70	mask |= bit;
 71	__raw_writel(mask, reg);
 72	local_irq_restore(flags);
 73}
 74
 75void disable_cayman_irq(unsigned int irq)
 76{
 77	unsigned long flags;
 78	unsigned long mask;
 79	unsigned int reg;
 80	unsigned char bit;
 81
 82	irq -= START_EXT_IRQS;
 83	reg = EPLD_MASK_BASE + ((irq / 8) << 2);
 84	bit = 1<<(irq % 8);
 85	local_irq_save(flags);
 86	mask = __raw_readl(reg);
 87	mask &= ~bit;
 88	__raw_writel(mask, reg);
 89	local_irq_restore(flags);
 90}
 91
 92static void ack_cayman_irq(unsigned int irq)
 93{
 94	disable_cayman_irq(irq);
 95}
 96
 97struct irq_chip cayman_irq_type = {
 98	.name		= "Cayman-IRQ",
 99	.unmask 	= enable_cayman_irq,
100	.mask		= disable_cayman_irq,
101	.mask_ack	= ack_cayman_irq,
102};
103
104int cayman_irq_demux(int evt)
105{
106	int irq = intc_evt_to_irq[evt];
107
108	if (irq == SMSC_IRQ) {
109		unsigned long status;
110		int i;
111
112		status = __raw_readl(EPLD_STATUS_BASE) &
113			 __raw_readl(EPLD_MASK_BASE) & 0xff;
114		if (status == 0) {
115			irq = -1;
116		} else {
117			for (i=0; i<8; i++) {
118				if (status & (1<<i))
119					break;
120			}
121			irq = START_EXT_IRQS + i;
122		}
123	}
124
125	if (irq == PCI2_IRQ) {
126		unsigned long status;
127		int i;
128
129		status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
130			 __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
131		if (status == 0) {
132			irq = -1;
133		} else {
134			for (i=0; i<8; i++) {
135				if (status & (1<<i))
136					break;
137			}
138			irq = START_EXT_IRQS + (3 * 8) + i;
139		}
140	}
141
142	return irq;
143}
144
145void init_cayman_irq(void)
146{
147	int i;
148
149	epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
150	if (!epld_virt) {
151		printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
152		return;
153	}
154
155	for (i = 0; i < NR_EXT_IRQS; i++) {
156		set_irq_chip_and_handler(START_EXT_IRQS + i, &cayman_irq_type,
157					 handle_level_irq);
158	}
159
160	/* Setup the SMSC interrupt */
161	setup_irq(SMSC_IRQ, &cayman_action_smsc);
162	setup_irq(PCI2_IRQ, &cayman_action_pci2);
163}