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
25 unsigned 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
cayman_interrupt_smsc(int irq,void * dev_id)34 static 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
cayman_interrupt_pci2(int irq,void * dev_id)40 static 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
46 static struct irqaction cayman_action_smsc = {
47 .name = "Cayman SMSC Mux",
48 .handler = cayman_interrupt_smsc,
49 };
50
51 static struct irqaction cayman_action_pci2 = {
52 .name = "Cayman PCI2 Mux",
53 .handler = cayman_interrupt_pci2,
54 };
55
enable_cayman_irq(struct irq_data * data)56 static 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
disable_cayman_irq(struct irq_data * data)74 static 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
92 struct irq_chip cayman_irq_type = {
93 .name = "Cayman-IRQ",
94 .irq_unmask = enable_cayman_irq,
95 .irq_mask = disable_cayman_irq,
96 };
97
cayman_irq_demux(int evt)98 int 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
init_cayman_irq(void)139 void 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 }
158