xref: /linux/arch/mips/rb532/irq.c (revision d608d71cd6d19792487d08333d63c7ff20294694)
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/random.h>
40 #include <linux/delay.h>
41 
42 #include <asm/bootinfo.h>
43 #include <asm/time.h>
44 #include <asm/mipsregs.h>
45 
46 #include <asm/mach-rc32434/irq.h>
47 #include <asm/mach-rc32434/gpio.h>
48 
49 struct intr_group {
50 	u32 mask;	/* mask of valid bits in pending/mask registers */
51 	volatile u32 *base_addr;
52 };
53 
54 #define RC32434_NR_IRQS	 (GROUP4_IRQ_BASE + 32)
55 
56 #if (NR_IRQS < RC32434_NR_IRQS)
57 #error Too little irqs defined. Did you override <asm/irq.h> ?
58 #endif
59 
60 static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
61 	{
62 		.mask	= 0x0000efff,
63 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
64 	{
65 		.mask	= 0x00001fff,
66 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
67 	{
68 		.mask	= 0x00000007,
69 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
70 	{
71 		.mask	= 0x0003ffff,
72 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
73 	{
74 		.mask	= 0xffffffff,
75 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
76 };
77 
78 #define READ_PEND(base) (*(base))
79 #define READ_MASK(base) (*(base + 2))
80 #define WRITE_MASK(base, val) (*(base + 2) = (val))
81 
82 static inline int irq_to_group(unsigned int irq_nr)
83 {
84 	return (irq_nr - GROUP0_IRQ_BASE) >> 5;
85 }
86 
87 static inline int group_to_ip(unsigned int group)
88 {
89 	return group + 2;
90 }
91 
92 static inline void enable_local_irq(unsigned int ip)
93 {
94 	int ipnum = 0x100 << ip;
95 
96 	set_c0_status(ipnum);
97 }
98 
99 static inline void disable_local_irq(unsigned int ip)
100 {
101 	int ipnum = 0x100 << ip;
102 
103 	clear_c0_status(ipnum);
104 }
105 
106 static inline void ack_local_irq(unsigned int ip)
107 {
108 	int ipnum = 0x100 << ip;
109 
110 	clear_c0_cause(ipnum);
111 }
112 
113 static void rb532_enable_irq(struct irq_data *d)
114 {
115 	unsigned int group, intr_bit, irq_nr = d->irq;
116 	int ip = irq_nr - GROUP0_IRQ_BASE;
117 	volatile unsigned int *addr;
118 
119 	if (ip < 0)
120 		enable_local_irq(irq_nr);
121 	else {
122 		group = ip >> 5;
123 
124 		ip &= (1 << 5) - 1;
125 		intr_bit = 1 << ip;
126 
127 		enable_local_irq(group_to_ip(group));
128 
129 		addr = intr_group[group].base_addr;
130 		WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
131 	}
132 }
133 
134 static void rb532_disable_irq(struct irq_data *d)
135 {
136 	unsigned int group, intr_bit, mask, irq_nr = d->irq;
137 	int ip = irq_nr - GROUP0_IRQ_BASE;
138 	volatile unsigned int *addr;
139 
140 	if (ip < 0) {
141 		disable_local_irq(irq_nr);
142 	} else {
143 		group = ip >> 5;
144 
145 		ip &= (1 << 5) - 1;
146 		intr_bit = 1 << ip;
147 		addr = intr_group[group].base_addr;
148 		mask = READ_MASK(addr);
149 		mask |= intr_bit;
150 		WRITE_MASK(addr, mask);
151 
152 		/* There is a maximum of 14 GPIO interrupts */
153 		if (group == GPIO_MAPPED_IRQ_GROUP && irq_nr <= (GROUP4_IRQ_BASE + 13))
154 			rb532_gpio_set_istat(0, irq_nr - GPIO_MAPPED_IRQ_BASE);
155 
156 		/*
157 		 * if there are no more interrupts enabled in this
158 		 * group, disable corresponding IP
159 		 */
160 		if (mask == intr_group[group].mask)
161 			disable_local_irq(group_to_ip(group));
162 	}
163 }
164 
165 static void rb532_mask_and_ack_irq(struct irq_data *d)
166 {
167 	rb532_disable_irq(d);
168 	ack_local_irq(group_to_ip(irq_to_group(d->irq)));
169 }
170 
171 static int rb532_set_type(struct irq_data *d,  unsigned type)
172 {
173 	int gpio = d->irq - GPIO_MAPPED_IRQ_BASE;
174 	int group = irq_to_group(d->irq);
175 
176 	if (group != GPIO_MAPPED_IRQ_GROUP || d->irq > (GROUP4_IRQ_BASE + 13))
177 		return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
178 
179 	switch (type) {
180 	case IRQ_TYPE_LEVEL_HIGH:
181 		rb532_gpio_set_ilevel(1, gpio);
182 		break;
183 	case IRQ_TYPE_LEVEL_LOW:
184 		rb532_gpio_set_ilevel(0, gpio);
185 		break;
186 	default:
187 		return -EINVAL;
188 	}
189 
190 	return 0;
191 }
192 
193 static struct irq_chip rc32434_irq_type = {
194 	.name		= "RB532",
195 	.irq_ack	= rb532_disable_irq,
196 	.irq_mask	= rb532_disable_irq,
197 	.irq_mask_ack	= rb532_mask_and_ack_irq,
198 	.irq_unmask	= rb532_enable_irq,
199 	.irq_set_type	= rb532_set_type,
200 };
201 
202 void __init arch_init_irq(void)
203 {
204 	int i;
205 
206 	pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
207 
208 	for (i = 0; i < RC32434_NR_IRQS; i++)
209 		irq_set_chip_and_handler(i, &rc32434_irq_type,
210 					 handle_level_irq);
211 }
212 
213 /* Main Interrupt dispatcher */
214 asmlinkage void plat_irq_dispatch(void)
215 {
216 	unsigned int ip, pend, group;
217 	volatile unsigned int *addr;
218 	unsigned int cp0_cause = read_c0_cause() & read_c0_status();
219 
220 	if (cp0_cause & CAUSEF_IP7) {
221 		do_IRQ(7);
222 	} else {
223 		ip = (cp0_cause & 0x7c00);
224 		if (ip) {
225 			group = 21 + (fls(ip) - 32);
226 
227 			addr = intr_group[group].base_addr;
228 
229 			pend = READ_PEND(addr);
230 			pend &= ~READ_MASK(addr);	/* only unmasked interrupts */
231 			pend = 39 + (fls(pend) - 32);
232 			do_IRQ((group << 5) + pend);
233 		}
234 	}
235 }
236