xref: /openbmc/linux/arch/m68k/coldfire/intc-5272.c (revision 4a44a19b)
1 /*
2  * intc.c  --  interrupt controller or ColdFire 5272 SoC
3  *
4  * (C) Copyright 2009, Greg Ungerer <gerg@snapgear.com>
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file COPYING in the main directory of this archive
8  * for more details.
9  */
10 
11 #include <linux/types.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/irq.h>
17 #include <linux/io.h>
18 #include <asm/coldfire.h>
19 #include <asm/mcfsim.h>
20 #include <asm/traps.h>
21 
22 /*
23  * The 5272 ColdFire interrupt controller is nothing like any other
24  * ColdFire interrupt controller - it truly is completely different.
25  * Given its age it is unlikely to be used on any other ColdFire CPU.
26  */
27 
28 /*
29  * The masking and priproty setting of interrupts on the 5272 is done
30  * via a set of 4 "Interrupt Controller Registers" (ICR). There is a
31  * loose mapping of vector number to register and internal bits, but
32  * a table is the easiest and quickest way to map them.
33  *
34  * Note that the external interrupts are edge triggered (unlike the
35  * internal interrupt sources which are level triggered). Which means
36  * they also need acknowledging via acknowledge bits.
37  */
38 struct irqmap {
39 	unsigned int	icr;
40 	unsigned char	index;
41 	unsigned char	ack;
42 };
43 
44 static struct irqmap intc_irqmap[MCFINT_VECMAX - MCFINT_VECBASE] = {
45 	/*MCF_IRQ_SPURIOUS*/	{ .icr = 0,           .index = 0,  .ack = 0, },
46 	/*MCF_IRQ_EINT1*/	{ .icr = MCFSIM_ICR1, .index = 28, .ack = 1, },
47 	/*MCF_IRQ_EINT2*/	{ .icr = MCFSIM_ICR1, .index = 24, .ack = 1, },
48 	/*MCF_IRQ_EINT3*/	{ .icr = MCFSIM_ICR1, .index = 20, .ack = 1, },
49 	/*MCF_IRQ_EINT4*/	{ .icr = MCFSIM_ICR1, .index = 16, .ack = 1, },
50 	/*MCF_IRQ_TIMER1*/	{ .icr = MCFSIM_ICR1, .index = 12, .ack = 0, },
51 	/*MCF_IRQ_TIMER2*/	{ .icr = MCFSIM_ICR1, .index = 8,  .ack = 0, },
52 	/*MCF_IRQ_TIMER3*/	{ .icr = MCFSIM_ICR1, .index = 4,  .ack = 0, },
53 	/*MCF_IRQ_TIMER4*/	{ .icr = MCFSIM_ICR1, .index = 0,  .ack = 0, },
54 	/*MCF_IRQ_UART1*/	{ .icr = MCFSIM_ICR2, .index = 28, .ack = 0, },
55 	/*MCF_IRQ_UART2*/	{ .icr = MCFSIM_ICR2, .index = 24, .ack = 0, },
56 	/*MCF_IRQ_PLIP*/	{ .icr = MCFSIM_ICR2, .index = 20, .ack = 0, },
57 	/*MCF_IRQ_PLIA*/	{ .icr = MCFSIM_ICR2, .index = 16, .ack = 0, },
58 	/*MCF_IRQ_USB0*/	{ .icr = MCFSIM_ICR2, .index = 12, .ack = 0, },
59 	/*MCF_IRQ_USB1*/	{ .icr = MCFSIM_ICR2, .index = 8,  .ack = 0, },
60 	/*MCF_IRQ_USB2*/	{ .icr = MCFSIM_ICR2, .index = 4,  .ack = 0, },
61 	/*MCF_IRQ_USB3*/	{ .icr = MCFSIM_ICR2, .index = 0,  .ack = 0, },
62 	/*MCF_IRQ_USB4*/	{ .icr = MCFSIM_ICR3, .index = 28, .ack = 0, },
63 	/*MCF_IRQ_USB5*/	{ .icr = MCFSIM_ICR3, .index = 24, .ack = 0, },
64 	/*MCF_IRQ_USB6*/	{ .icr = MCFSIM_ICR3, .index = 20, .ack = 0, },
65 	/*MCF_IRQ_USB7*/	{ .icr = MCFSIM_ICR3, .index = 16, .ack = 0, },
66 	/*MCF_IRQ_DMA*/		{ .icr = MCFSIM_ICR3, .index = 12, .ack = 0, },
67 	/*MCF_IRQ_ERX*/		{ .icr = MCFSIM_ICR3, .index = 8,  .ack = 0, },
68 	/*MCF_IRQ_ETX*/		{ .icr = MCFSIM_ICR3, .index = 4,  .ack = 0, },
69 	/*MCF_IRQ_ENTC*/	{ .icr = MCFSIM_ICR3, .index = 0,  .ack = 0, },
70 	/*MCF_IRQ_QSPI*/	{ .icr = MCFSIM_ICR4, .index = 28, .ack = 0, },
71 	/*MCF_IRQ_EINT5*/	{ .icr = MCFSIM_ICR4, .index = 24, .ack = 1, },
72 	/*MCF_IRQ_EINT6*/	{ .icr = MCFSIM_ICR4, .index = 20, .ack = 1, },
73 	/*MCF_IRQ_SWTO*/	{ .icr = MCFSIM_ICR4, .index = 16, .ack = 0, },
74 };
75 
76 /*
77  * The act of masking the interrupt also has a side effect of 'ack'ing
78  * an interrupt on this irq (for the external irqs). So this mask function
79  * is also an ack_mask function.
80  */
81 static void intc_irq_mask(struct irq_data *d)
82 {
83 	unsigned int irq = d->irq;
84 
85 	if ((irq >= MCFINT_VECBASE) && (irq <= MCFINT_VECMAX)) {
86 		u32 v;
87 		irq -= MCFINT_VECBASE;
88 		v = 0x8 << intc_irqmap[irq].index;
89 		writel(v, intc_irqmap[irq].icr);
90 	}
91 }
92 
93 static void intc_irq_unmask(struct irq_data *d)
94 {
95 	unsigned int irq = d->irq;
96 
97 	if ((irq >= MCFINT_VECBASE) && (irq <= MCFINT_VECMAX)) {
98 		u32 v;
99 		irq -= MCFINT_VECBASE;
100 		v = 0xd << intc_irqmap[irq].index;
101 		writel(v, intc_irqmap[irq].icr);
102 	}
103 }
104 
105 static void intc_irq_ack(struct irq_data *d)
106 {
107 	unsigned int irq = d->irq;
108 
109 	/* Only external interrupts are acked */
110 	if ((irq >= MCFINT_VECBASE) && (irq <= MCFINT_VECMAX)) {
111 		irq -= MCFINT_VECBASE;
112 		if (intc_irqmap[irq].ack) {
113 			u32 v;
114 			v = readl(intc_irqmap[irq].icr);
115 			v &= (0x7 << intc_irqmap[irq].index);
116 			v |= (0x8 << intc_irqmap[irq].index);
117 			writel(v, intc_irqmap[irq].icr);
118 		}
119 	}
120 }
121 
122 static int intc_irq_set_type(struct irq_data *d, unsigned int type)
123 {
124 	unsigned int irq = d->irq;
125 
126 	if ((irq >= MCFINT_VECBASE) && (irq <= MCFINT_VECMAX)) {
127 		irq -= MCFINT_VECBASE;
128 		if (intc_irqmap[irq].ack) {
129 			u32 v;
130 			v = readl(MCFSIM_PITR);
131 			if (type == IRQ_TYPE_EDGE_FALLING)
132 				v &= ~(0x1 << (32 - irq));
133 			else
134 				v |= (0x1 << (32 - irq));
135 			writel(v, MCFSIM_PITR);
136 		}
137 	}
138 	return 0;
139 }
140 
141 /*
142  * Simple flow handler to deal with the external edge triggered interrupts.
143  * We need to be careful with the masking/acking due to the side effects
144  * of masking an interrupt.
145  */
146 static void intc_external_irq(unsigned int irq, struct irq_desc *desc)
147 {
148 	irq_desc_get_chip(desc)->irq_ack(&desc->irq_data);
149 	handle_simple_irq(irq, desc);
150 }
151 
152 static struct irq_chip intc_irq_chip = {
153 	.name		= "CF-INTC",
154 	.irq_mask	= intc_irq_mask,
155 	.irq_unmask	= intc_irq_unmask,
156 	.irq_mask_ack	= intc_irq_mask,
157 	.irq_ack	= intc_irq_ack,
158 	.irq_set_type	= intc_irq_set_type,
159 };
160 
161 void __init init_IRQ(void)
162 {
163 	int irq, edge;
164 
165 	/* Mask all interrupt sources */
166 	writel(0x88888888, MCFSIM_ICR1);
167 	writel(0x88888888, MCFSIM_ICR2);
168 	writel(0x88888888, MCFSIM_ICR3);
169 	writel(0x88888888, MCFSIM_ICR4);
170 
171 	for (irq = 0; (irq < NR_IRQS); irq++) {
172 		irq_set_chip(irq, &intc_irq_chip);
173 		edge = 0;
174 		if ((irq >= MCFINT_VECBASE) && (irq <= MCFINT_VECMAX))
175 			edge = intc_irqmap[irq - MCFINT_VECBASE].ack;
176 		if (edge) {
177 			irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
178 			irq_set_handler(irq, intc_external_irq);
179 		} else {
180 			irq_set_irq_type(irq, IRQ_TYPE_LEVEL_HIGH);
181 			irq_set_handler(irq, handle_level_irq);
182 		}
183 	}
184 }
185 
186