1 /*
2 * Interrupt controller driver for Xilinx Virtex FPGAs
3 *
4 * Copyright (C) 2007 Secret Lab Technologies Ltd.
5 *
6 * This file is licensed under the terms of the GNU General Public License
7 * version 2. This program is licensed "as is" without any warranty of any
8 * kind, whether express or implied.
9 *
10 */
11
12 /*
13 * This is a driver for the interrupt controller typically found in
14 * Xilinx Virtex FPGA designs.
15 *
16 * The interrupt sense levels are hard coded into the FPGA design with
17 * typically a 1:1 relationship between irq lines and devices (no shared
18 * irq lines). Therefore, this driver does not attempt to handle edge
19 * and level interrupts differently.
20 */
21 #undef DEBUG
22
23 #include <linux/kernel.h>
24 #include <linux/irq.h>
25 #include <linux/of.h>
26 #include <asm/io.h>
27 #include <asm/processor.h>
28 #include <asm/irq.h>
29
30 /*
31 * INTC Registers
32 */
33 #define XINTC_ISR 0 /* Interrupt Status */
34 #define XINTC_IPR 4 /* Interrupt Pending */
35 #define XINTC_IER 8 /* Interrupt Enable */
36 #define XINTC_IAR 12 /* Interrupt Acknowledge */
37 #define XINTC_SIE 16 /* Set Interrupt Enable bits */
38 #define XINTC_CIE 20 /* Clear Interrupt Enable bits */
39 #define XINTC_IVR 24 /* Interrupt Vector */
40 #define XINTC_MER 28 /* Master Enable */
41
42 static struct irq_host *master_irqhost;
43
44 /*
45 * IRQ Chip operations
46 */
xilinx_intc_mask(unsigned int virq)47 static void xilinx_intc_mask(unsigned int virq)
48 {
49 int irq = virq_to_hw(virq);
50 void * regs = get_irq_chip_data(virq);
51 pr_debug("mask: %d\n", irq);
52 out_be32(regs + XINTC_CIE, 1 << irq);
53 }
54
xilinx_intc_unmask(unsigned int virq)55 static void xilinx_intc_unmask(unsigned int virq)
56 {
57 int irq = virq_to_hw(virq);
58 void * regs = get_irq_chip_data(virq);
59 pr_debug("unmask: %d\n", irq);
60 out_be32(regs + XINTC_SIE, 1 << irq);
61 }
62
xilinx_intc_ack(unsigned int virq)63 static void xilinx_intc_ack(unsigned int virq)
64 {
65 int irq = virq_to_hw(virq);
66 void * regs = get_irq_chip_data(virq);
67 pr_debug("ack: %d\n", irq);
68 out_be32(regs + XINTC_IAR, 1 << irq);
69 }
70
71 static struct irq_chip xilinx_intc_irqchip = {
72 .typename = "Xilinx INTC",
73 .mask = xilinx_intc_mask,
74 .unmask = xilinx_intc_unmask,
75 .ack = xilinx_intc_ack,
76 };
77
78 /*
79 * IRQ Host operations
80 */
xilinx_intc_map(struct irq_host * h,unsigned int virq,irq_hw_number_t irq)81 static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
82 irq_hw_number_t irq)
83 {
84 set_irq_chip_data(virq, h->host_data);
85 set_irq_chip_and_handler(virq, &xilinx_intc_irqchip, handle_level_irq);
86 set_irq_type(virq, IRQ_TYPE_NONE);
87 return 0;
88 }
89
90 static struct irq_host_ops xilinx_intc_ops = {
91 .map = xilinx_intc_map,
92 };
93
94 struct irq_host * __init
xilinx_intc_init(struct device_node * np)95 xilinx_intc_init(struct device_node *np)
96 {
97 struct irq_host * irq;
98 struct resource res;
99 void * regs;
100 int rc;
101
102 /* Find and map the intc registers */
103 rc = of_address_to_resource(np, 0, &res);
104 if (rc) {
105 printk(KERN_ERR __FILE__ ": of_address_to_resource() failed\n");
106 return NULL;
107 }
108 regs = ioremap(res.start, 32);
109
110 printk(KERN_INFO "Xilinx intc at 0x%08llx mapped to 0x%p\n",
111 (unsigned long long) res.start, regs);
112
113 /* Setup interrupt controller */
114 out_be32(regs + XINTC_IER, 0); /* disable all irqs */
115 out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
116 out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
117
118 /* Allocate and initialize an irq_host structure. */
119 irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 32, &xilinx_intc_ops, -1);
120 if (!irq)
121 panic(__FILE__ ": Cannot allocate IRQ host\n");
122 irq->host_data = regs;
123 return irq;
124 }
125
xilinx_intc_get_irq(void)126 int xilinx_intc_get_irq(void)
127 {
128 void * regs = master_irqhost->host_data;
129 pr_debug("get_irq:\n");
130 return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR));
131 }
132
xilinx_intc_init_tree(void)133 void __init xilinx_intc_init_tree(void)
134 {
135 struct device_node *np;
136
137 /* find top level interrupt controller */
138 for_each_compatible_node(np, NULL, "xlnx,opb-intc-1.00.c") {
139 if (!of_get_property(np, "interrupts", NULL))
140 break;
141 }
142 if (!np) {
143 for_each_compatible_node(np, NULL, "xlnx,xps-intc-1.00.a") {
144 if (!of_get_property(np, "interrupts", NULL))
145 break;
146 }
147 }
148
149 /* xilinx interrupt controller needs to be top level */
150 BUG_ON(!np);
151
152 master_irqhost = xilinx_intc_init(np);
153 BUG_ON(!master_irqhost);
154
155 irq_set_default_host(master_irqhost);
156 of_node_put(np);
157 }
158