1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/mach-cayman/irq.c - SH-5 Cayman Interrupt Support
4 *
5 * This file handles the board specific parts of the Cayman interrupt system
6 *
7 * Copyright (C) 2002 Stuart Menefy
8 */
9 #include <linux/io.h>
10 #include <linux/irq.h>
11 #include <linux/interrupt.h>
12 #include <linux/signal.h>
13 #include <cpu/irq.h>
14 #include <asm/page.h>
15
16 /* Setup for the SMSC FDC37C935 / LAN91C100FD */
17 #define SMSC_IRQ IRQ_IRL1
18
19 /* Setup for PCI Bus 2, which transmits interrupts via the EPLD */
20 #define PCI2_IRQ IRQ_IRL3
21
22 unsigned long epld_virt;
23
24 #define EPLD_BASE 0x04002000
25 #define EPLD_STATUS_BASE (epld_virt + 0x10)
26 #define EPLD_MASK_BASE (epld_virt + 0x20)
27
28 /* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto
29 the same SH-5 interrupt */
30
cayman_interrupt_smsc(int irq,void * dev_id)31 static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id)
32 {
33 printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
34 return IRQ_NONE;
35 }
36
cayman_interrupt_pci2(int irq,void * dev_id)37 static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id)
38 {
39 printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq);
40 return IRQ_NONE;
41 }
42
43 static struct irqaction cayman_action_smsc = {
44 .name = "Cayman SMSC Mux",
45 .handler = cayman_interrupt_smsc,
46 };
47
48 static struct irqaction cayman_action_pci2 = {
49 .name = "Cayman PCI2 Mux",
50 .handler = cayman_interrupt_pci2,
51 };
52
enable_cayman_irq(struct irq_data * data)53 static void enable_cayman_irq(struct irq_data *data)
54 {
55 unsigned int irq = data->irq;
56 unsigned long flags;
57 unsigned long mask;
58 unsigned int reg;
59 unsigned char bit;
60
61 irq -= START_EXT_IRQS;
62 reg = EPLD_MASK_BASE + ((irq / 8) << 2);
63 bit = 1<<(irq % 8);
64 local_irq_save(flags);
65 mask = __raw_readl(reg);
66 mask |= bit;
67 __raw_writel(mask, reg);
68 local_irq_restore(flags);
69 }
70
disable_cayman_irq(struct irq_data * data)71 static void disable_cayman_irq(struct irq_data *data)
72 {
73 unsigned int irq = data->irq;
74 unsigned long flags;
75 unsigned long mask;
76 unsigned int reg;
77 unsigned char bit;
78
79 irq -= START_EXT_IRQS;
80 reg = EPLD_MASK_BASE + ((irq / 8) << 2);
81 bit = 1<<(irq % 8);
82 local_irq_save(flags);
83 mask = __raw_readl(reg);
84 mask &= ~bit;
85 __raw_writel(mask, reg);
86 local_irq_restore(flags);
87 }
88
89 struct irq_chip cayman_irq_type = {
90 .name = "Cayman-IRQ",
91 .irq_unmask = enable_cayman_irq,
92 .irq_mask = disable_cayman_irq,
93 };
94
cayman_irq_demux(int evt)95 int cayman_irq_demux(int evt)
96 {
97 int irq = intc_evt_to_irq[evt];
98
99 if (irq == SMSC_IRQ) {
100 unsigned long status;
101 int i;
102
103 status = __raw_readl(EPLD_STATUS_BASE) &
104 __raw_readl(EPLD_MASK_BASE) & 0xff;
105 if (status == 0) {
106 irq = -1;
107 } else {
108 for (i=0; i<8; i++) {
109 if (status & (1<<i))
110 break;
111 }
112 irq = START_EXT_IRQS + i;
113 }
114 }
115
116 if (irq == PCI2_IRQ) {
117 unsigned long status;
118 int i;
119
120 status = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
121 __raw_readl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
122 if (status == 0) {
123 irq = -1;
124 } else {
125 for (i=0; i<8; i++) {
126 if (status & (1<<i))
127 break;
128 }
129 irq = START_EXT_IRQS + (3 * 8) + i;
130 }
131 }
132
133 return irq;
134 }
135
init_cayman_irq(void)136 void init_cayman_irq(void)
137 {
138 int i;
139
140 epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
141 if (!epld_virt) {
142 printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
143 return;
144 }
145
146 for (i = 0; i < NR_EXT_IRQS; i++) {
147 irq_set_chip_and_handler(START_EXT_IRQS + i,
148 &cayman_irq_type, handle_level_irq);
149 }
150
151 /* Setup the SMSC interrupt */
152 setup_irq(SMSC_IRQ, &cayman_action_smsc);
153 setup_irq(PCI2_IRQ, &cayman_action_pci2);
154 }
155
