2 * Interrupt controller driver for Xilinx Virtex FPGAs
4 * Copyright (C) 2007 Secret Lab Technologies Ltd.
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.
13 * This is a driver for the interrupt controller typically found in
14 * Xilinx Virtex FPGA designs.
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.
23 #include <linux/kernel.h>
24 #include <linux/irq.h>
26 #include <linux/of_address.h>
28 #include <asm/processor.h>
29 #include <asm/i8259.h>
35 #define XINTC_ISR 0 /* Interrupt Status */
36 #define XINTC_IPR 4 /* Interrupt Pending */
37 #define XINTC_IER 8 /* Interrupt Enable */
38 #define XINTC_IAR 12 /* Interrupt Acknowledge */
39 #define XINTC_SIE 16 /* Set Interrupt Enable bits */
40 #define XINTC_CIE 20 /* Clear Interrupt Enable bits */
41 #define XINTC_IVR 24 /* Interrupt Vector */
42 #define XINTC_MER 28 /* Master Enable */
44 static struct irq_domain *master_irqhost;
46 #define XILINX_INTC_MAXIRQS (32)
48 /* The following table allows the interrupt type, edge or level,
49 * to be cached after being read from the device tree until the interrupt
52 static int xilinx_intc_typetable[XILINX_INTC_MAXIRQS];
54 /* Map the interrupt type from the device tree to the interrupt types
55 * used by the interrupt subsystem
57 static unsigned char xilinx_intc_map_senses[] = {
59 IRQ_TYPE_EDGE_FALLING,
65 * The interrupt controller is setup such that it doesn't work well with
66 * the level interrupt handler in the kernel because the handler acks the
67 * interrupt before calling the application interrupt handler. To deal with
68 * that, we use 2 different irq chips so that different functions can be
69 * used for level and edge type interrupts.
71 * IRQ Chip common (across level and edge) operations
73 static void xilinx_intc_mask(struct irq_data *d)
75 int irq = irqd_to_hwirq(d);
76 void * regs = irq_data_get_irq_chip_data(d);
77 pr_debug("mask: %d\n", irq);
78 out_be32(regs + XINTC_CIE, 1 << irq);
81 static int xilinx_intc_set_type(struct irq_data *d, unsigned int flow_type)
87 * IRQ Chip level operations
89 static void xilinx_intc_level_unmask(struct irq_data *d)
91 int irq = irqd_to_hwirq(d);
92 void * regs = irq_data_get_irq_chip_data(d);
93 pr_debug("unmask: %d\n", irq);
94 out_be32(regs + XINTC_SIE, 1 << irq);
96 /* ack level irqs because they can't be acked during
97 * ack function since the handle_level_irq function
98 * acks the irq before calling the inerrupt handler
100 out_be32(regs + XINTC_IAR, 1 << irq);
103 static struct irq_chip xilinx_intc_level_irqchip = {
104 .name = "Xilinx Level INTC",
105 .irq_mask = xilinx_intc_mask,
106 .irq_mask_ack = xilinx_intc_mask,
107 .irq_unmask = xilinx_intc_level_unmask,
108 .irq_set_type = xilinx_intc_set_type,
112 * IRQ Chip edge operations
114 static void xilinx_intc_edge_unmask(struct irq_data *d)
116 int irq = irqd_to_hwirq(d);
117 void *regs = irq_data_get_irq_chip_data(d);
118 pr_debug("unmask: %d\n", irq);
119 out_be32(regs + XINTC_SIE, 1 << irq);
122 static void xilinx_intc_edge_ack(struct irq_data *d)
124 int irq = irqd_to_hwirq(d);
125 void * regs = irq_data_get_irq_chip_data(d);
126 pr_debug("ack: %d\n", irq);
127 out_be32(regs + XINTC_IAR, 1 << irq);
130 static struct irq_chip xilinx_intc_edge_irqchip = {
131 .name = "Xilinx Edge INTC",
132 .irq_mask = xilinx_intc_mask,
133 .irq_unmask = xilinx_intc_edge_unmask,
134 .irq_ack = xilinx_intc_edge_ack,
135 .irq_set_type = xilinx_intc_set_type,
139 * IRQ Host operations
143 * xilinx_intc_xlate - translate virq# from device tree interrupts property
145 static int xilinx_intc_xlate(struct irq_domain *h, struct device_node *ct,
146 const u32 *intspec, unsigned int intsize,
147 irq_hw_number_t *out_hwirq,
148 unsigned int *out_flags)
150 if ((intsize < 2) || (intspec[0] >= XILINX_INTC_MAXIRQS))
153 /* keep a copy of the interrupt type til the interrupt is mapped
155 xilinx_intc_typetable[intspec[0]] = xilinx_intc_map_senses[intspec[1]];
157 /* Xilinx uses 2 interrupt entries, the 1st being the h/w
158 * interrupt number, the 2nd being the interrupt type, edge or level
160 *out_hwirq = intspec[0];
161 *out_flags = xilinx_intc_map_senses[intspec[1]];
165 static int xilinx_intc_map(struct irq_domain *h, unsigned int virq,
168 irq_set_chip_data(virq, h->host_data);
170 if (xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_HIGH ||
171 xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_LOW) {
172 irq_set_chip_and_handler(virq, &xilinx_intc_level_irqchip,
175 irq_set_chip_and_handler(virq, &xilinx_intc_edge_irqchip,
181 static struct irq_domain_ops xilinx_intc_ops = {
182 .map = xilinx_intc_map,
183 .xlate = xilinx_intc_xlate,
186 struct irq_domain * __init
187 xilinx_intc_init(struct device_node *np)
189 struct irq_domain * irq;
192 /* Find and map the intc registers */
193 regs = of_iomap(np, 0);
195 pr_err("xilinx_intc: could not map registers\n");
199 /* Setup interrupt controller */
200 out_be32(regs + XINTC_IER, 0); /* disable all irqs */
201 out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
202 out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
204 /* Allocate and initialize an irq_domain structure. */
205 irq = irq_domain_add_linear(np, XILINX_INTC_MAXIRQS, &xilinx_intc_ops,
208 panic(__FILE__ ": Cannot allocate IRQ host\n");
213 int xilinx_intc_get_irq(void)
215 void * regs = master_irqhost->host_data;
216 pr_debug("get_irq:\n");
217 return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR));
220 #if defined(CONFIG_PPC_I8259)
222 * Support code for cascading to 8259 interrupt controllers
224 static void xilinx_i8259_cascade(unsigned int irq, struct irq_desc *desc)
226 struct irq_chip *chip = irq_desc_get_chip(desc);
227 unsigned int cascade_irq = i8259_irq();
230 generic_handle_irq(cascade_irq);
232 /* Let xilinx_intc end the interrupt */
233 chip->irq_unmask(&desc->irq_data);
236 static void __init xilinx_i8259_setup_cascade(void)
238 struct device_node *cascade_node;
241 /* Initialize i8259 controller */
242 cascade_node = of_find_compatible_node(NULL, NULL, "chrp,iic");
246 cascade_irq = irq_of_parse_and_map(cascade_node, 0);
248 pr_err("virtex_ml510: Failed to map cascade interrupt\n");
252 i8259_init(cascade_node, 0);
253 irq_set_chained_handler(cascade_irq, xilinx_i8259_cascade);
255 /* Program irq 7 (usb/audio), 14/15 (ide) to level sensitive */
256 /* This looks like a dirty hack to me --gcl */
261 of_node_put(cascade_node);
264 static inline void xilinx_i8259_setup_cascade(void) { return; }
265 #endif /* defined(CONFIG_PPC_I8259) */
267 static struct of_device_id xilinx_intc_match[] __initconst = {
268 { .compatible = "xlnx,opb-intc-1.00.c", },
269 { .compatible = "xlnx,xps-intc-1.00.a", },
274 * Initialize master Xilinx interrupt controller
276 void __init xilinx_intc_init_tree(void)
278 struct device_node *np;
280 /* find top level interrupt controller */
281 for_each_matching_node(np, xilinx_intc_match) {
282 if (!of_get_property(np, "interrupts", NULL))
287 master_irqhost = xilinx_intc_init(np);
288 BUG_ON(!master_irqhost);
290 irq_set_default_host(master_irqhost);
293 xilinx_i8259_setup_cascade();