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};
 50
 51static struct irqaction cayman_action_pci2 = {
 52	.name		= "Cayman PCI2 Mux",
 53	.handler	= cayman_interrupt_pci2,
 54};
 55
 56static void enable_cayman_irq(struct irq_data *data)
 57{
 58	unsigned int irq = data->irq;
 59	unsigned long flags;
 60	unsigned long mask;
 61	unsigned int reg;
 62	unsigned char bit;
 63
 64	irq -= START_EXT_IRQS;
 65	reg = EPLD_MASK_BASE + ((irq / 8) << 2);
 66	bit = 1<<(irq % 8);
 67	local_irq_save(flags);
 68	mask = __raw_readl(reg);
 69	mask |= bit;
 70	__raw_writel(mask, reg);
 71	local_irq_restore(flags);
 72}
 73
 74static void disable_cayman_irq(struct irq_data *data)
 75{
 76	unsigned int irq = data->irq;
 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
 92struct irq_chip cayman_irq_type = {
 93	.name		= "Cayman-IRQ",
 94	.irq_unmask	= enable_cayman_irq,
 95	.irq_mask	= disable_cayman_irq,
 96};
 97
 98int cayman_irq_demux(int evt)
 99{
100	int irq = intc_evt_to_irq[evt];
101
102	if (irq == SMSC_IRQ) {
103		unsigned long status;
104		int i;
105
106		status = __raw_readl(EPLD_STATUS_BASE) &
107			 __raw_readl(EPLD_MASK_BASE) & 0xff;
108		if (status == 0) {
109			irq = -1;
110		} else {
111			for (i=0; i<8; i++) {
112				if (status & (1<<i))
113					break;
114			}
115			irq = START_EXT_IRQS + i;
116		}
117	}
118
119	if (irq == PCI2_IRQ) {
120		unsigned long status;
121		int i;
122
123		status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
124			 __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
125		if (status == 0) {
126			irq = -1;
127		} else {
128			for (i=0; i<8; i++) {
129				if (status & (1<<i))
130					break;
131			}
132			irq = START_EXT_IRQS + (3 * 8) + i;
133		}
134	}
135
136	return irq;
137}
138
139void init_cayman_irq(void)
140{
141	int i;
142
143	epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
144	if (!epld_virt) {
145		printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
146		return;
147	}
148
149	for (i = 0; i < NR_EXT_IRQS; i++) {
150		irq_set_chip_and_handler(START_EXT_IRQS + i,
151					 &cayman_irq_type, handle_level_irq);
152	}
153
154	/* Setup the SMSC interrupt */
155	setup_irq(SMSC_IRQ, &cayman_action_smsc);
156	setup_irq(PCI2_IRQ, &cayman_action_pci2);
157}