xref: /openbmc/linux/arch/mips/rb532/irq.c (revision e65e175b)
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/signal.h>
33 #include <linux/sched.h>
34 #include <linux/types.h>
35 #include <linux/interrupt.h>
36 #include <linux/ioport.h>
37 #include <linux/timex.h>
38 #include <linux/random.h>
39 #include <linux/delay.h>
40 
41 #include <asm/bootinfo.h>
42 #include <asm/time.h>
43 #include <asm/mipsregs.h>
44 
45 #include <asm/mach-rc32434/irq.h>
46 #include <asm/mach-rc32434/gpio.h>
47 
48 struct intr_group {
49 	u32 mask;	/* mask of valid bits in pending/mask registers */
50 	volatile u32 *base_addr;
51 };
52 
53 #define RC32434_NR_IRQS	 (GROUP4_IRQ_BASE + 32)
54 
55 #if (NR_IRQS < RC32434_NR_IRQS)
56 #error Too little irqs defined. Did you override <asm/irq.h> ?
57 #endif
58 
59 static const struct intr_group intr_group[NUM_INTR_GROUPS] = {
60 	{
61 		.mask	= 0x0000efff,
62 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 0 * IC_GROUP_OFFSET)},
63 	{
64 		.mask	= 0x00001fff,
65 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 1 * IC_GROUP_OFFSET)},
66 	{
67 		.mask	= 0x00000007,
68 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 2 * IC_GROUP_OFFSET)},
69 	{
70 		.mask	= 0x0003ffff,
71 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 3 * IC_GROUP_OFFSET)},
72 	{
73 		.mask	= 0xffffffff,
74 		.base_addr = (u32 *) KSEG1ADDR(IC_GROUP0_PEND + 4 * IC_GROUP_OFFSET)}
75 };
76 
77 #define READ_PEND(base) (*(base))
78 #define READ_MASK(base) (*(base + 2))
79 #define WRITE_MASK(base, val) (*(base + 2) = (val))
80 
81 static inline int irq_to_group(unsigned int irq_nr)
82 {
83 	return (irq_nr - GROUP0_IRQ_BASE) >> 5;
84 }
85 
86 static inline int group_to_ip(unsigned int group)
87 {
88 	return group + 2;
89 }
90 
91 static inline void enable_local_irq(unsigned int ip)
92 {
93 	int ipnum = 0x100 << ip;
94 
95 	set_c0_status(ipnum);
96 }
97 
98 static inline void disable_local_irq(unsigned int ip)
99 {
100 	int ipnum = 0x100 << ip;
101 
102 	clear_c0_status(ipnum);
103 }
104 
105 static inline void ack_local_irq(unsigned int ip)
106 {
107 	int ipnum = 0x100 << ip;
108 
109 	clear_c0_cause(ipnum);
110 }
111 
112 static void rb532_enable_irq(struct irq_data *d)
113 {
114 	unsigned int group, intr_bit, irq_nr = d->irq;
115 	int ip = irq_nr - GROUP0_IRQ_BASE;
116 	volatile unsigned int *addr;
117 
118 	if (ip < 0)
119 		enable_local_irq(irq_nr);
120 	else {
121 		group = ip >> 5;
122 
123 		ip &= (1 << 5) - 1;
124 		intr_bit = 1 << ip;
125 
126 		enable_local_irq(group_to_ip(group));
127 
128 		addr = intr_group[group].base_addr;
129 		WRITE_MASK(addr, READ_MASK(addr) & ~intr_bit);
130 	}
131 }
132 
133 static void rb532_disable_irq(struct irq_data *d)
134 {
135 	unsigned int group, intr_bit, mask, irq_nr = d->irq;
136 	int ip = irq_nr - GROUP0_IRQ_BASE;
137 	volatile unsigned int *addr;
138 
139 	if (ip < 0) {
140 		disable_local_irq(irq_nr);
141 	} else {
142 		group = ip >> 5;
143 
144 		ip &= (1 << 5) - 1;
145 		intr_bit = 1 << ip;
146 		addr = intr_group[group].base_addr;
147 		mask = READ_MASK(addr);
148 		mask |= intr_bit;
149 		WRITE_MASK(addr, mask);
150 
151 		/* There is a maximum of 14 GPIO interrupts */
152 		if (group == GPIO_MAPPED_IRQ_GROUP && irq_nr <= (GROUP4_IRQ_BASE + 13))
153 			rb532_gpio_set_istat(0, irq_nr - GPIO_MAPPED_IRQ_BASE);
154 
155 		/*
156 		 * if there are no more interrupts enabled in this
157 		 * group, disable corresponding IP
158 		 */
159 		if (mask == intr_group[group].mask)
160 			disable_local_irq(group_to_ip(group));
161 	}
162 }
163 
164 static void rb532_mask_and_ack_irq(struct irq_data *d)
165 {
166 	rb532_disable_irq(d);
167 	ack_local_irq(group_to_ip(irq_to_group(d->irq)));
168 }
169 
170 static int rb532_set_type(struct irq_data *d,  unsigned type)
171 {
172 	int gpio = d->irq - GPIO_MAPPED_IRQ_BASE;
173 	int group = irq_to_group(d->irq);
174 
175 	if (group != GPIO_MAPPED_IRQ_GROUP || d->irq > (GROUP4_IRQ_BASE + 13))
176 		return (type == IRQ_TYPE_LEVEL_HIGH) ? 0 : -EINVAL;
177 
178 	switch (type) {
179 	case IRQ_TYPE_LEVEL_HIGH:
180 		rb532_gpio_set_ilevel(1, gpio);
181 		break;
182 	case IRQ_TYPE_LEVEL_LOW:
183 		rb532_gpio_set_ilevel(0, gpio);
184 		break;
185 	default:
186 		return -EINVAL;
187 	}
188 
189 	return 0;
190 }
191 
192 static struct irq_chip rc32434_irq_type = {
193 	.name		= "RB532",
194 	.irq_ack	= rb532_disable_irq,
195 	.irq_mask	= rb532_disable_irq,
196 	.irq_mask_ack	= rb532_mask_and_ack_irq,
197 	.irq_unmask	= rb532_enable_irq,
198 	.irq_set_type	= rb532_set_type,
199 };
200 
201 void __init arch_init_irq(void)
202 {
203 	int i;
204 
205 	pr_info("Initializing IRQ's: %d out of %d\n", RC32434_NR_IRQS, NR_IRQS);
206 
207 	for (i = 0; i < RC32434_NR_IRQS; i++)
208 		irq_set_chip_and_handler(i, &rc32434_irq_type,
209 					 handle_level_irq);
210 }
211 
212 /* Main Interrupt dispatcher */
213 asmlinkage void plat_irq_dispatch(void)
214 {
215 	unsigned int ip, pend, group;
216 	volatile unsigned int *addr;
217 	unsigned int cp0_cause = read_c0_cause() & read_c0_status();
218 
219 	if (cp0_cause & CAUSEF_IP7) {
220 		do_IRQ(7);
221 	} else {
222 		ip = (cp0_cause & 0x7c00);
223 		if (ip) {
224 			group = 21 + (fls(ip) - 32);
225 
226 			addr = intr_group[group].base_addr;
227 
228 			pend = READ_PEND(addr);
229 			pend &= ~READ_MASK(addr);	/* only unmasked interrupts */
230 			pend = 39 + (fls(pend) - 32);
231 			do_IRQ((group << 5) + pend);
232 		}
233 	}
234 }
235