xref: /openbmc/linux/arch/mips/rb532/irq.c (revision 93dc544c)
1 /*
2  *  This program is free software; you can redistribute  it and/or modify it
3  *  under  the terms of  the GNU General  Public License as published by the
4  *  Free Software Foundation;  either version 2 of the  License, or (at your
5  *  option) any later version.
6  *
7  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
8  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
9  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
10  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
11  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
12  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
13  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
14  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
15  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
16  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
17  *
18  *  You should have received a copy of the  GNU General Public License along
19  *  with this program; if not, write  to the Free Software Foundation, Inc.,
20  *  675 Mass Ave, Cambridge, MA 02139, USA.
21  *
22  * Copyright 2002 MontaVista Software Inc.
23  * Author: MontaVista Software, Inc.
24  *              stevel@mvista.com or source@mvista.com
25  */
26 
27 #include <linux/bitops.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/io.h>
31 #include <linux/kernel_stat.h>
32 #include <linux/module.h>
33 #include <linux/signal.h>
34 #include <linux/sched.h>
35 #include <linux/types.h>
36 #include <linux/interrupt.h>
37 #include <linux/ioport.h>
38 #include <linux/timex.h>
39 #include <linux/slab.h>
40 #include <linux/random.h>
41 #include <linux/delay.h>
42 
43 #include <asm/bootinfo.h>
44 #include <asm/time.h>
45 #include <asm/mipsregs.h>
46 #include <asm/system.h>
47 
48 #include <asm/mach-rc32434/rc32434.h>
49 
50 struct intr_group {
51 	u32 mask;	/* mask of valid bits in pending/mask registers */
52 	volatile u32 *base_addr;
53 };
54 
55 #define RC32434_NR_IRQS  (GROUP4_IRQ_BASE + 32)
56 
57 #if (NR_IRQS < RC32434_NR_IRQS)
58 #error Too little irqs defined. Did you override <asm/irq.h> ?
59 #endif
60 
61 static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
62 	{
63 		.mask	= 0x0000efff,
64 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
65 	{
66 		.mask	= 0x00001fff,
67 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
68 	{
69 		.mask	= 0x00000007,
70 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
71 	{
72 		.mask	= 0x0003ffff,
73 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
74 	{
75 		.mask	= 0xffffffff,
76 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
77 };
78 
79 #define READ_PEND(base) (*(base))
80 #define READ_MASK(base) (*(base + 2))
81 #define WRITE_MASK(base, val) (*(base + 2) = (val))
82 
83 static inline int irq_to_group(unsigned int irq_nr)
84 {
85 	return (irq_nr - GROUP0_IRQ_BASE) >> 5;
86 }
87 
88 static inline int group_to_ip(unsigned int group)
89 {
90 	return group + 2;
91 }
92 
93 static inline void enable_local_irq(unsigned int ip)
94 {
95 	int ipnum = 0x100 << ip;
96 
97 	set_c0_status(ipnum);
98 }
99 
100 static inline void disable_local_irq(unsigned int ip)
101 {
102 	int ipnum = 0x100 << ip;
103 
104 	clear_c0_status(ipnum);
105 }
106 
107 static inline void ack_local_irq(unsigned int ip)
108 {
109 	int ipnum = 0x100 << ip;
110 
111 	clear_c0_cause(ipnum);
112 }
113 
114 static void rb532_enable_irq(unsigned int irq_nr)
115 {
116 	int ip = irq_nr - GROUP0_IRQ_BASE;
117 	unsigned int group, intr_bit;
118 	volatile unsigned int *addr;
119 
120 	if (ip < 0)
121 		enable_local_irq(irq_nr);
122 	else {
123 		group = ip >> 5;
124 
125 		ip &= (1 << 5) - 1;
126 		intr_bit = 1 << ip;
127 
128 		enable_local_irq(group_to_ip(group));
129 
130 		addr = intr_group[group].base_addr;
131 		WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
132 	}
133 }
134 
135 static void rb532_disable_irq(unsigned int irq_nr)
136 {
137 	int ip = irq_nr - GROUP0_IRQ_BASE;
138 	unsigned int group, intr_bit, mask;
139 	volatile unsigned int *addr;
140 
141 	if (ip < 0) {
142 		disable_local_irq(irq_nr);
143 	} else {
144 		group = ip >> 5;
145 
146 		ip &= (1 << 5) - 1;
147 		intr_bit = 1 << ip;
148 		addr = intr_group[group].base_addr;
149 		mask = READ_MASK(addr);
150 		mask |= intr_bit;
151 		WRITE_MASK(addr, mask);
152 
153 		/*
154 		 * if there are no more interrupts enabled in this
155 		 * group, disable corresponding IP
156 		 */
157 		if (mask == intr_group[group].mask)
158 			disable_local_irq(group_to_ip(group));
159 	}
160 }
161 
162 static void rb532_mask_and_ack_irq(unsigned int irq_nr)
163 {
164 	rb532_disable_irq(irq_nr);
165 	ack_local_irq(group_to_ip(irq_to_group(irq_nr)));
166 }
167 
168 static struct irq_chip rc32434_irq_type = {
169 	.name		= "RB532",
170 	.ack		= rb532_disable_irq,
171 	.mask		= rb532_disable_irq,
172 	.mask_ack	= rb532_mask_and_ack_irq,
173 	.unmask		= rb532_enable_irq,
174 };
175 
176 void __init arch_init_irq(void)
177 {
178 	int i;
179 
180 	pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
181 
182 	for (i = 0; i < RC32434_NR_IRQS; i++)
183 		set_irq_chip_and_handler(i,  &rc32434_irq_type,
184 					handle_level_irq);
185 }
186 
187 /* Main Interrupt dispatcher */
188 asmlinkage void plat_irq_dispatch(void)
189 {
190 	unsigned int ip, pend, group;
191 	volatile unsigned int *addr;
192 	unsigned int cp0_cause = read_c0_cause() & read_c0_status();
193 
194 	if (cp0_cause & CAUSEF_IP7) {
195 		do_IRQ(7);
196 	} else {
197 		ip = (cp0_cause & 0x7c00);
198 		if (ip) {
199 			group = 21 + (fls(ip) - 32);
200 
201 			addr = intr_group[group].base_addr;
202 
203 			pend = READ_PEND(addr);
204 			pend &= ~READ_MASK(addr);	/* only unmasked interrupts */
205 			pend = 39 + (fls(pend) - 32);
206 			do_IRQ((group << 5) + pend);
207 		}
208 	}
209 }
210