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(struct irq_data * data)58 static void enable_cayman_irq(struct irq_data *data)
59 {
60 unsigned int irq = data->irq;
61 unsigned long flags;
62 unsigned long mask;
63 unsigned int reg;
64 unsigned char bit;
65
66 irq -= START_EXT_IRQS;
67 reg = EPLD_MASK_BASE + ((irq / 8) << 2);
68 bit = 1<<(irq % 8);
69 local_irq_save(flags);
70 mask = __raw_readl(reg);
71 mask |= bit;
72 __raw_writel(mask, reg);
73 local_irq_restore(flags);
74 }
75
disable_cayman_irq(struct irq_data * data)76 static void disable_cayman_irq(struct irq_data *data)
77 {
78 unsigned int irq = data->irq;
79 unsigned long flags;
80 unsigned long mask;
81 unsigned int reg;
82 unsigned char bit;
83
84 irq -= START_EXT_IRQS;
85 reg = EPLD_MASK_BASE + ((irq / 8) << 2);
86 bit = 1<<(irq % 8);
87 local_irq_save(flags);
88 mask = __raw_readl(reg);
89 mask &= ~bit;
90 __raw_writel(mask, reg);
91 local_irq_restore(flags);
92 }
93
94 struct irq_chip cayman_irq_type = {
95 .name = "Cayman-IRQ",
96 .irq_unmask = enable_cayman_irq,
97 .irq_mask = disable_cayman_irq,
98 };
99
cayman_irq_demux(int evt)100 int cayman_irq_demux(int evt)
101 {
102 int irq = intc_evt_to_irq[evt];
103
104 if (irq == SMSC_IRQ) {
105 unsigned long status;
106 int i;
107
108 status = __raw_readl(EPLD_STATUS_BASE) &
109 __raw_readl(EPLD_MASK_BASE) & 0xff;
110 if (status == 0) {
111 irq = -1;
112 } else {
113 for (i=0; i<8; i++) {
114 if (status & (1<<i))
115 break;
116 }
117 irq = START_EXT_IRQS + i;
118 }
119 }
120
121 if (irq == PCI2_IRQ) {
122 unsigned long status;
123 int i;
124
125 status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
126 __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
127 if (status == 0) {
128 irq = -1;
129 } else {
130 for (i=0; i<8; i++) {
131 if (status & (1<<i))
132 break;
133 }
134 irq = START_EXT_IRQS + (3 * 8) + i;
135 }
136 }
137
138 return irq;
139 }
140
init_cayman_irq(void)141 void init_cayman_irq(void)
142 {
143 int i;
144
145 epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
146 if (!epld_virt) {
147 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
148 return;
149 }
150
151 for (i = 0; i < NR_EXT_IRQS; i++) {
152 irq_set_chip_and_handler(START_EXT_IRQS + i,
153 &cayman_irq_type, handle_level_irq);
154 }
155
156 /* Setup the SMSC interrupt */
157 setup_irq(SMSC_IRQ, &cayman_action_smsc);
158 setup_irq(PCI2_IRQ, &cayman_action_pci2);
159 }
160