xref: /openbmc/linux/arch/powerpc/platforms/8xx/pic.c (revision 9a29f5fc)
1 #include <linux/kernel.h>
2 #include <linux/stddef.h>
3 #include <linux/sched.h>
4 #include <linux/signal.h>
5 #include <linux/irq.h>
6 #include <linux/dma-mapping.h>
7 #include <linux/of_address.h>
8 #include <linux/of_irq.h>
9 #include <asm/irq.h>
10 #include <asm/io.h>
11 #include <asm/8xx_immap.h>
12 
13 #include "pic.h"
14 
15 
16 #define PIC_VEC_SPURRIOUS      15
17 
18 static struct irq_domain *mpc8xx_pic_host;
19 static unsigned long mpc8xx_cached_irq_mask;
20 static sysconf8xx_t __iomem *siu_reg;
21 
22 static inline unsigned long mpc8xx_irqd_to_bit(struct irq_data *d)
23 {
24 	return 0x80000000 >> irqd_to_hwirq(d);
25 }
26 
27 static void mpc8xx_unmask_irq(struct irq_data *d)
28 {
29 	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
30 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
31 }
32 
33 static void mpc8xx_mask_irq(struct irq_data *d)
34 {
35 	mpc8xx_cached_irq_mask &= ~mpc8xx_irqd_to_bit(d);
36 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
37 }
38 
39 static void mpc8xx_ack(struct irq_data *d)
40 {
41 	out_be32(&siu_reg->sc_sipend, mpc8xx_irqd_to_bit(d));
42 }
43 
44 static void mpc8xx_end_irq(struct irq_data *d)
45 {
46 	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
47 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
48 }
49 
50 static int mpc8xx_set_irq_type(struct irq_data *d, unsigned int flow_type)
51 {
52 	/* only external IRQ senses are programmable */
53 	if ((flow_type & IRQ_TYPE_EDGE_FALLING) && !(irqd_to_hwirq(d) & 1)) {
54 		unsigned int siel = in_be32(&siu_reg->sc_siel);
55 		siel |= mpc8xx_irqd_to_bit(d);
56 		out_be32(&siu_reg->sc_siel, siel);
57 		irq_set_handler_locked(d, handle_edge_irq);
58 	}
59 	return 0;
60 }
61 
62 static struct irq_chip mpc8xx_pic = {
63 	.name = "8XX SIU",
64 	.irq_unmask = mpc8xx_unmask_irq,
65 	.irq_mask = mpc8xx_mask_irq,
66 	.irq_ack = mpc8xx_ack,
67 	.irq_eoi = mpc8xx_end_irq,
68 	.irq_set_type = mpc8xx_set_irq_type,
69 };
70 
71 unsigned int mpc8xx_get_irq(void)
72 {
73 	int irq;
74 
75 	/* For MPC8xx, read the SIVEC register and shift the bits down
76 	 * to get the irq number.
77 	 */
78 	irq = in_be32(&siu_reg->sc_sivec) >> 26;
79 
80 	if (irq == PIC_VEC_SPURRIOUS)
81 		return 0;
82 
83         return irq_linear_revmap(mpc8xx_pic_host, irq);
84 
85 }
86 
87 static int mpc8xx_pic_host_map(struct irq_domain *h, unsigned int virq,
88 			  irq_hw_number_t hw)
89 {
90 	pr_debug("mpc8xx_pic_host_map(%d, 0x%lx)\n", virq, hw);
91 
92 	/* Set default irq handle */
93 	irq_set_chip_and_handler(virq, &mpc8xx_pic, handle_level_irq);
94 	return 0;
95 }
96 
97 
98 static int mpc8xx_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
99 			    const u32 *intspec, unsigned int intsize,
100 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
101 {
102 	static unsigned char map_pic_senses[4] = {
103 		IRQ_TYPE_EDGE_RISING,
104 		IRQ_TYPE_LEVEL_LOW,
105 		IRQ_TYPE_LEVEL_HIGH,
106 		IRQ_TYPE_EDGE_FALLING,
107 	};
108 
109 	if (intspec[0] > 0x1f)
110 		return 0;
111 
112 	*out_hwirq = intspec[0];
113 	if (intsize > 1 && intspec[1] < 4)
114 		*out_flags = map_pic_senses[intspec[1]];
115 	else
116 		*out_flags = IRQ_TYPE_NONE;
117 
118 	return 0;
119 }
120 
121 
122 static const struct irq_domain_ops mpc8xx_pic_host_ops = {
123 	.map = mpc8xx_pic_host_map,
124 	.xlate = mpc8xx_pic_host_xlate,
125 };
126 
127 void __init mpc8xx_pic_init(void)
128 {
129 	struct resource res;
130 	struct device_node *np;
131 	int ret;
132 
133 	np = of_find_compatible_node(NULL, NULL, "fsl,pq1-pic");
134 	if (np == NULL)
135 		np = of_find_node_by_type(NULL, "mpc8xx-pic");
136 	if (np == NULL) {
137 		printk(KERN_ERR "Could not find fsl,pq1-pic node\n");
138 		return;
139 	}
140 
141 	ret = of_address_to_resource(np, 0, &res);
142 	if (ret)
143 		goto out;
144 
145 	siu_reg = ioremap(res.start, resource_size(&res));
146 	if (!siu_reg)
147 		goto out;
148 
149 	mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops, NULL);
150 	if (!mpc8xx_pic_host)
151 		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
152 
153 out:
154 	of_node_put(np);
155 }
156