xref: /openbmc/linux/arch/powerpc/platforms/8xx/pic.c (revision d3964221)
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 <asm/prom.h>
8 #include <asm/irq.h>
9 #include <asm/io.h>
10 #include <asm/8xx_immap.h>
11 
12 #include "pic.h"
13 
14 
15 #define PIC_VEC_SPURRIOUS      15
16 
17 extern int cpm_get_irq(struct pt_regs *regs);
18 
19 static struct irq_domain *mpc8xx_pic_host;
20 static unsigned long mpc8xx_cached_irq_mask;
21 static sysconf8xx_t __iomem *siu_reg;
22 
23 static inline unsigned long mpc8xx_irqd_to_bit(struct irq_data *d)
24 {
25 	return 0x80000000 >> irqd_to_hwirq(d);
26 }
27 
28 static void mpc8xx_unmask_irq(struct irq_data *d)
29 {
30 	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
31 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
32 }
33 
34 static void mpc8xx_mask_irq(struct irq_data *d)
35 {
36 	mpc8xx_cached_irq_mask &= ~mpc8xx_irqd_to_bit(d);
37 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
38 }
39 
40 static void mpc8xx_ack(struct irq_data *d)
41 {
42 	out_be32(&siu_reg->sc_sipend, mpc8xx_irqd_to_bit(d));
43 }
44 
45 static void mpc8xx_end_irq(struct irq_data *d)
46 {
47 	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
48 	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
49 }
50 
51 static int mpc8xx_set_irq_type(struct irq_data *d, unsigned int flow_type)
52 {
53 	/* only external IRQ senses are programmable */
54 	if ((flow_type & IRQ_TYPE_EDGE_FALLING) && !(irqd_to_hwirq(d) & 1)) {
55 		unsigned int siel = in_be32(&siu_reg->sc_siel);
56 		siel |= mpc8xx_irqd_to_bit(d);
57 		out_be32(&siu_reg->sc_siel, siel);
58 		irq_set_handler_locked(d, handle_edge_irq);
59 	}
60 	return 0;
61 }
62 
63 static struct irq_chip mpc8xx_pic = {
64 	.name = "8XX SIU",
65 	.irq_unmask = mpc8xx_unmask_irq,
66 	.irq_mask = mpc8xx_mask_irq,
67 	.irq_ack = mpc8xx_ack,
68 	.irq_eoi = mpc8xx_end_irq,
69 	.irq_set_type = mpc8xx_set_irq_type,
70 };
71 
72 unsigned int mpc8xx_get_irq(void)
73 {
74 	int irq;
75 
76 	/* For MPC8xx, read the SIVEC register and shift the bits down
77 	 * to get the irq number.
78 	 */
79 	irq = in_be32(&siu_reg->sc_sivec) >> 26;
80 
81 	if (irq == PIC_VEC_SPURRIOUS)
82 		return 0;
83 
84         return irq_linear_revmap(mpc8xx_pic_host, irq);
85 
86 }
87 
88 static int mpc8xx_pic_host_map(struct irq_domain *h, unsigned int virq,
89 			  irq_hw_number_t hw)
90 {
91 	pr_debug("mpc8xx_pic_host_map(%d, 0x%lx)\n", virq, hw);
92 
93 	/* Set default irq handle */
94 	irq_set_chip_and_handler(virq, &mpc8xx_pic, handle_level_irq);
95 	return 0;
96 }
97 
98 
99 static int mpc8xx_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
100 			    const u32 *intspec, unsigned int intsize,
101 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
102 {
103 	static unsigned char map_pic_senses[4] = {
104 		IRQ_TYPE_EDGE_RISING,
105 		IRQ_TYPE_LEVEL_LOW,
106 		IRQ_TYPE_LEVEL_HIGH,
107 		IRQ_TYPE_EDGE_FALLING,
108 	};
109 
110 	if (intspec[0] > 0x1f)
111 		return 0;
112 
113 	*out_hwirq = intspec[0];
114 	if (intsize > 1 && intspec[1] < 4)
115 		*out_flags = map_pic_senses[intspec[1]];
116 	else
117 		*out_flags = IRQ_TYPE_NONE;
118 
119 	return 0;
120 }
121 
122 
123 static const struct irq_domain_ops mpc8xx_pic_host_ops = {
124 	.map = mpc8xx_pic_host_map,
125 	.xlate = mpc8xx_pic_host_xlate,
126 };
127 
128 int mpc8xx_pic_init(void)
129 {
130 	struct resource res;
131 	struct device_node *np;
132 	int ret;
133 
134 	np = of_find_compatible_node(NULL, NULL, "fsl,pq1-pic");
135 	if (np == NULL)
136 		np = of_find_node_by_type(NULL, "mpc8xx-pic");
137 	if (np == NULL) {
138 		printk(KERN_ERR "Could not find fsl,pq1-pic node\n");
139 		return -ENOMEM;
140 	}
141 
142 	ret = of_address_to_resource(np, 0, &res);
143 	if (ret)
144 		goto out;
145 
146 	siu_reg = ioremap(res.start, resource_size(&res));
147 	if (siu_reg == NULL) {
148 		ret = -EINVAL;
149 		goto out;
150 	}
151 
152 	mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops, NULL);
153 	if (mpc8xx_pic_host == NULL) {
154 		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
155 		ret = -ENOMEM;
156 		goto out;
157 	}
158 	return 0;
159 
160 out:
161 	of_node_put(np);
162 	return ret;
163 }
164