tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2012-2013 Xilinx, Inc.
4 * Copyright (C) 2007-2009 PetaLogix
5 * Copyright (C) 2006 Atmark Techno, Inc.
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11
12#include <linux/irqdomain.h>
13#include <linux/irq.h>
14#include <linux/irqchip.h>
15#include <linux/of_address.h>
16#include <linux/io.h>
17#include <linux/bug.h>
18
19static void __iomem *intc_baseaddr;
20
21/* No one else should require these constants, so define them locally here. */
22#define ISR 0x00 /* Interrupt Status Register */
23#define IPR 0x04 /* Interrupt Pending Register */
24#define IER 0x08 /* Interrupt Enable Register */
25#define IAR 0x0c /* Interrupt Acknowledge Register */
26#define SIE 0x10 /* Set Interrupt Enable bits */
27#define CIE 0x14 /* Clear Interrupt Enable bits */
28#define IVR 0x18 /* Interrupt Vector Register */
29#define MER 0x1c /* Master Enable Register */
30
31#define MER_ME (1<<0)
32#define MER_HIE (1<<1)
33
34static unsigned int (*read_fn)(void __iomem *);
35static void (*write_fn)(u32, void __iomem *);
36
37static void intc_write32(u32 val, void __iomem *addr)
38{
39 iowrite32(val, addr);
40}
41
42static unsigned int intc_read32(void __iomem *addr)
43{
44 return ioread32(addr);
45}
46
47static void intc_write32_be(u32 val, void __iomem *addr)
48{
49 iowrite32be(val, addr);
50}
51
52static unsigned int intc_read32_be(void __iomem *addr)
53{
54 return ioread32be(addr);
55}
56
57static void intc_enable_or_unmask(struct irq_data *d)
58{
59 unsigned long mask = 1 << d->hwirq;
60
61 pr_debug("enable_or_unmask: %ld\n", d->hwirq);
62
63 /* ack level irqs because they can't be acked during
64 * ack function since the handle_level_irq function
65 * acks the irq before calling the interrupt handler
66 */
67 if (irqd_is_level_type(d))
68 write_fn(mask, intc_baseaddr + IAR);
69
70 write_fn(mask, intc_baseaddr + SIE);
71}
72
73static void intc_disable_or_mask(struct irq_data *d)
74{
75 pr_debug("disable: %ld\n", d->hwirq);
76 write_fn(1 << d->hwirq, intc_baseaddr + CIE);
77}
78
79static void intc_ack(struct irq_data *d)
80{
81 pr_debug("ack: %ld\n", d->hwirq);
82 write_fn(1 << d->hwirq, intc_baseaddr + IAR);
83}
84
85static void intc_mask_ack(struct irq_data *d)
86{
87 unsigned long mask = 1 << d->hwirq;
88
89 pr_debug("disable_and_ack: %ld\n", d->hwirq);
90 write_fn(mask, intc_baseaddr + CIE);
91 write_fn(mask, intc_baseaddr + IAR);
92}
93
94static struct irq_chip intc_dev = {
95 .name = "Xilinx INTC",
96 .irq_unmask = intc_enable_or_unmask,
97 .irq_mask = intc_disable_or_mask,
98 .irq_ack = intc_ack,
99 .irq_mask_ack = intc_mask_ack,
100};
101
102static struct irq_domain *root_domain;
103
104unsigned int get_irq(void)
105{
106 unsigned int hwirq, irq = -1;
107
108 hwirq = read_fn(intc_baseaddr + IVR);
109 if (hwirq != -1U)
110 irq = irq_find_mapping(root_domain, hwirq);
111
112 pr_debug("get_irq: hwirq=%d, irq=%d\n", hwirq, irq);
113
114 return irq;
115}
116
117static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
118{
119 u32 intr_mask = (u32)d->host_data;
120
121 if (intr_mask & (1 << hw)) {
122 irq_set_chip_and_handler_name(irq, &intc_dev,
123 handle_edge_irq, "edge");
124 irq_clear_status_flags(irq, IRQ_LEVEL);
125 } else {
126 irq_set_chip_and_handler_name(irq, &intc_dev,
127 handle_level_irq, "level");
128 irq_set_status_flags(irq, IRQ_LEVEL);
129 }
130 return 0;
131}
132
133static const struct irq_domain_ops xintc_irq_domain_ops = {
134 .xlate = irq_domain_xlate_onetwocell,
135 .map = xintc_map,
136};
137
138static int __init xilinx_intc_of_init(struct device_node *intc,
139 struct device_node *parent)
140{
141 u32 nr_irq, intr_mask;
142 int ret;
143
144 intc_baseaddr = of_iomap(intc, 0);
145 BUG_ON(!intc_baseaddr);
146
147 ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
148 if (ret < 0) {
149 pr_err("%s: unable to read xlnx,num-intr-inputs\n", __func__);
150 return ret;
151 }
152
153 ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &intr_mask);
154 if (ret < 0) {
155 pr_err("%s: unable to read xlnx,kind-of-intr\n", __func__);
156 return ret;
157 }
158
159 if (intr_mask >> nr_irq)
160 pr_warn("%s: mismatch in kind-of-intr param\n", __func__);
161
162 pr_info("%s: num_irq=%d, edge=0x%x\n",
163 intc->full_name, nr_irq, intr_mask);
164
165 write_fn = intc_write32;
166 read_fn = intc_read32;
167
168 /*
169 * Disable all external interrupts until they are
170 * explicity requested.
171 */
172 write_fn(0, intc_baseaddr + IER);
173
174 /* Acknowledge any pending interrupts just in case. */
175 write_fn(0xffffffff, intc_baseaddr + IAR);
176
177 /* Turn on the Master Enable. */
178 write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
179 if (!(read_fn(intc_baseaddr + MER) & (MER_HIE | MER_ME))) {
180 write_fn = intc_write32_be;
181 read_fn = intc_read32_be;
182 write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
183 }
184
185 /* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
186 * lazy and Michal can clean it up to something nicer when he tests
187 * and commits this patch. ~~gcl */
188 root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
189 (void *)intr_mask);
190
191 irq_set_default_host(root_domain);
192
193 return 0;
194}
195
196IRQCHIP_DECLARE(xilinx_intc, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);