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 .flags = IRQF_DISABLED,
50 };
51
52 static struct irqaction cayman_action_pci2 = {
53 .name = "Cayman PCI2 Mux",
54 .handler = cayman_interrupt_pci2,
55 .flags = IRQF_DISABLED,
56 };
57
enable_cayman_irq(unsigned int irq)58 static 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 = ctrl_inl(reg);
70 mask |= bit;
71 ctrl_outl(mask, reg);
72 local_irq_restore(flags);
73 }
74
disable_cayman_irq(unsigned int irq)75 void 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 = ctrl_inl(reg);
87 mask &= ~bit;
88 ctrl_outl(mask, reg);
89 local_irq_restore(flags);
90 }
91
ack_cayman_irq(unsigned int irq)92 static void ack_cayman_irq(unsigned int irq)
93 {
94 disable_cayman_irq(irq);
95 }
96
97 struct 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
cayman_irq_demux(int evt)104 int 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 = ctrl_inl(EPLD_STATUS_BASE) &
113 ctrl_inl(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 = ctrl_inl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
130 ctrl_inl(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
145 #if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
cayman_irq_describe(char * p,int irq)146 int cayman_irq_describe(char* p, int irq)
147 {
148 if (irq < NR_INTC_IRQS) {
149 return intc_irq_describe(p, irq);
150 } else if (irq < NR_INTC_IRQS + 8) {
151 return sprintf(p, "(SMSC %d)", irq - NR_INTC_IRQS);
152 } else if ((irq >= NR_INTC_IRQS + 24) && (irq < NR_INTC_IRQS + 32)) {
153 return sprintf(p, "(PCI2 %d)", irq - (NR_INTC_IRQS + 24));
154 }
155
156 return 0;
157 }
158 #endif
159
init_cayman_irq(void)160 void init_cayman_irq(void)
161 {
162 int i;
163
164 epld_virt = onchip_remap(EPLD_BASE, 1024, "EPLD");
165 if (!epld_virt) {
166 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
167 return;
168 }
169
170 for (i = 0; i < NR_EXT_IRQS; i++) {
171 set_irq_chip_and_handler(START_EXT_IRQS + i, &cayman_irq_type,
172 handle_level_irq);
173 }
174
175 /* Setup the SMSC interrupt */
176 setup_irq(SMSC_IRQ, &cayman_action_smsc);
177 setup_irq(PCI2_IRQ, &cayman_action_pci2);
178 }
179