xref: /openbmc/linux/arch/mips/rb532/irq.c (revision b04b4f78)
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/irq.h>
49 #include <asm/mach-rc32434/gpio.h>
50 
51 struct intr_group {
52 	u32 mask;	/* mask of valid bits in pending/mask registers */
53 	volatile u32 *base_addr;
54 };
55 
56 #define RC32434_NR_IRQS  (GROUP4_IRQ_BASE + 32)
57 
58 #if (NR_IRQS < RC32434_NR_IRQS)
59 #error Too little irqs defined. Did you override <asm/irq.h> ?
60 #endif
61 
62 static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
63 	{
64 		.mask	= 0x0000efff,
65 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
66 	{
67 		.mask	= 0x00001fff,
68 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
69 	{
70 		.mask	= 0x00000007,
71 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
72 	{
73 		.mask	= 0x0003ffff,
74 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
75 	{
76 		.mask	= 0xffffffff,
77 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
78 };
79 
80 #define READ_PEND(base) (*(base))
81 #define READ_MASK(base) (*(base + 2))
82 #define WRITE_MASK(base, val) (*(base + 2) = (val))
83 
84 static inline int irq_to_group(unsigned int irq_nr)
85 {
86 	return (irq_nr - GROUP0_IRQ_BASE) >> 5;
87 }
88 
89 static inline int group_to_ip(unsigned int group)
90 {
91 	return group + 2;
92 }
93 
94 static inline void enable_local_irq(unsigned int ip)
95 {
96 	int ipnum = 0x100 << ip;
97 
98 	set_c0_status(ipnum);
99 }
100 
101 static inline void disable_local_irq(unsigned int ip)
102 {
103 	int ipnum = 0x100 << ip;
104 
105 	clear_c0_status(ipnum);
106 }
107 
108 static inline void ack_local_irq(unsigned int ip)
109 {
110 	int ipnum = 0x100 << ip;
111 
112 	clear_c0_cause(ipnum);
113 }
114 
115 static void rb532_enable_irq(unsigned int irq_nr)
116 {
117 	int ip = irq_nr - GROUP0_IRQ_BASE;
118 	unsigned int group, intr_bit;
119 	volatile unsigned int *addr;
120 
121 	if (ip < 0)
122 		enable_local_irq(irq_nr);
123 	else {
124 		group = ip >> 5;
125 
126 		ip &= (1 << 5) - 1;
127 		intr_bit = 1 << ip;
128 
129 		enable_local_irq(group_to_ip(group));
130 
131 		addr = intr_group[group].base_addr;
132 		WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
133 	}
134 }
135 
136 static void rb532_disable_irq(unsigned int irq_nr)
137 {
138 	int ip = irq_nr - GROUP0_IRQ_BASE;
139 	unsigned int group, intr_bit, mask;
140 	volatile unsigned int *addr;
141 
142 	if (ip < 0) {
143 		disable_local_irq(irq_nr);
144 	} else {
145 		group = ip >> 5;
146 
147 		ip &= (1 << 5) - 1;
148 		intr_bit = 1 << ip;
149 		addr = intr_group[group].base_addr;
150 		mask = READ_MASK(addr);
151 		mask |= intr_bit;
152 		WRITE_MASK(addr, mask);
153 
154 		if (group == GPIO_MAPPED_IRQ_GROUP)
155 			rb532_gpio_set_istat(0, irq_nr - GPIO_MAPPED_IRQ_BASE);
156 
157 		/*
158 		 * if there are no more interrupts enabled in this
159 		 * group, disable corresponding IP
160 		 */
161 		if (mask == intr_group[group].mask)
162 			disable_local_irq(group_to_ip(group));
163 	}
164 }
165 
166 static void rb532_mask_and_ack_irq(unsigned int irq_nr)
167 {
168 	rb532_disable_irq(irq_nr);
169 	ack_local_irq(group_to_ip(irq_to_group(irq_nr)));
170 }
171 
172 static int rb532_set_type(unsigned int irq_nr, unsigned type)
173 {
174 	int gpio = irq_nr - GPIO_MAPPED_IRQ_BASE;
175 	int group = irq_to_group(irq_nr);
176 
177 	if (group != GPIO_MAPPED_IRQ_GROUP)
178 		return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
179 
180 	switch (type) {
181 	case IRQ_TYPE_LEVEL_HIGH:
182 		rb532_gpio_set_ilevel(1, gpio);
183 		break;
184 	case IRQ_TYPE_LEVEL_LOW:
185 		rb532_gpio_set_ilevel(0, gpio);
186 		break;
187 	default:
188 		return -EINVAL;
189 	}
190 
191 	return 0;
192 }
193 
194 static struct irq_chip rc32434_irq_type = {
195 	.name		= "RB532",
196 	.ack		= rb532_disable_irq,
197 	.mask		= rb532_disable_irq,
198 	.mask_ack	= rb532_mask_and_ack_irq,
199 	.unmask		= rb532_enable_irq,
200 	.set_type	= rb532_set_type,
201 };
202 
203 void __init arch_init_irq(void)
204 {
205 	int i;
206 
207 	pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
208 
209 	for (i = 0; i < RC32434_NR_IRQS; i++)
210 		set_irq_chip_and_handler(i,  &rc32434_irq_type,
211 					handle_level_irq);
212 }
213 
214 /* Main Interrupt dispatcher */
215 asmlinkage void plat_irq_dispatch(void)
216 {
217 	unsigned int ip, pend, group;
218 	volatile unsigned int *addr;
219 	unsigned int cp0_cause = read_c0_cause() & read_c0_status();
220 
221 	if (cp0_cause & CAUSEF_IP7) {
222 		do_IRQ(7);
223 	} else {
224 		ip = (cp0_cause & 0x7c00);
225 		if (ip) {
226 			group = 21 + (fls(ip) - 32);
227 
228 			addr = intr_group[group].base_addr;
229 
230 			pend = READ_PEND(addr);
231 			pend &= ~READ_MASK(addr);	/* only unmasked interrupts */
232 			pend = 39 + (fls(pend) - 32);
233 			do_IRQ((group << 5) + pend);
234 		}
235 	}
236 }
237