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/irqchip/chained_irq.h>
16#include <linux/of_address.h>
17#include <linux/io.h>
18#include <linux/jump_label.h>
19#include <linux/bug.h>
20#include <linux/of_irq.h>
21
22/* No one else should require these constants, so define them locally here. */
23#define ISR 0x00 /* Interrupt Status Register */
24#define IPR 0x04 /* Interrupt Pending Register */
25#define IER 0x08 /* Interrupt Enable Register */
26#define IAR 0x0c /* Interrupt Acknowledge Register */
27#define SIE 0x10 /* Set Interrupt Enable bits */
28#define CIE 0x14 /* Clear Interrupt Enable bits */
29#define IVR 0x18 /* Interrupt Vector Register */
30#define MER 0x1c /* Master Enable Register */
31
32#define MER_ME (1<<0)
33#define MER_HIE (1<<1)
34
35#define SPURIOUS_IRQ (-1U)
36
37static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
38
39struct xintc_irq_chip {
40 void __iomem *base;
41 struct irq_domain *root_domain;
42 u32 intr_mask;
43 u32 nr_irq;
44};
45
46static struct xintc_irq_chip *primary_intc;
47
48static void xintc_write(struct xintc_irq_chip *irqc, int reg, u32 data)
49{
50 if (static_branch_unlikely(&xintc_is_be))
51 iowrite32be(data, irqc->base + reg);
52 else
53 iowrite32(data, irqc->base + reg);
54}
55
56static u32 xintc_read(struct xintc_irq_chip *irqc, int reg)
57{
58 if (static_branch_unlikely(&xintc_is_be))
59 return ioread32be(irqc->base + reg);
60 else
61 return ioread32(irqc->base + reg);
62}
63
64static void intc_enable_or_unmask(struct irq_data *d)
65{
66 struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
67 unsigned long mask = BIT(d->hwirq);
68
69 pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
70
71 /* ack level irqs because they can't be acked during
72 * ack function since the handle_level_irq function
73 * acks the irq before calling the interrupt handler
74 */
75 if (irqd_is_level_type(d))
76 xintc_write(irqc, IAR, data: mask);
77
78 xintc_write(irqc, SIE, data: mask);
79}
80
81static void intc_disable_or_mask(struct irq_data *d)
82{
83 struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
84
85 pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
86 xintc_write(irqc, CIE, BIT(d->hwirq));
87}
88
89static void intc_ack(struct irq_data *d)
90{
91 struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
92
93 pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
94 xintc_write(irqc, IAR, BIT(d->hwirq));
95}
96
97static void intc_mask_ack(struct irq_data *d)
98{
99 struct xintc_irq_chip *irqc = irq_data_get_irq_chip_data(d);
100 unsigned long mask = BIT(d->hwirq);
101
102 pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
103 xintc_write(irqc, CIE, data: mask);
104 xintc_write(irqc, IAR, data: mask);
105}
106
107static struct irq_chip intc_dev = {
108 .name = "Xilinx INTC",
109 .irq_unmask = intc_enable_or_unmask,
110 .irq_mask = intc_disable_or_mask,
111 .irq_ack = intc_ack,
112 .irq_mask_ack = intc_mask_ack,
113};
114
115static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
116{
117 struct xintc_irq_chip *irqc = d->host_data;
118
119 if (irqc->intr_mask & BIT(hw)) {
120 irq_set_chip_and_handler_name(irq, chip: &intc_dev,
121 handle: handle_edge_irq, name: "edge");
122 irq_clear_status_flags(irq, clr: IRQ_LEVEL);
123 } else {
124 irq_set_chip_and_handler_name(irq, chip: &intc_dev,
125 handle: handle_level_irq, name: "level");
126 irq_set_status_flags(irq, set: IRQ_LEVEL);
127 }
128 irq_set_chip_data(irq, data: irqc);
129 return 0;
130}
131
132static const struct irq_domain_ops xintc_irq_domain_ops = {
133 .xlate = irq_domain_xlate_onetwocell,
134 .map = xintc_map,
135};
136
137static void xil_intc_irq_handler(struct irq_desc *desc)
138{
139 struct irq_chip *chip = irq_desc_get_chip(desc);
140 struct xintc_irq_chip *irqc;
141
142 irqc = irq_data_get_irq_handler_data(d: &desc->irq_data);
143 chained_irq_enter(chip, desc);
144 do {
145 u32 hwirq = xintc_read(irqc, IVR);
146
147 if (hwirq == -1U)
148 break;
149
150 generic_handle_domain_irq(domain: irqc->root_domain, hwirq);
151 } while (true);
152 chained_irq_exit(chip, desc);
153}
154
155static void xil_intc_handle_irq(struct pt_regs *regs)
156{
157 u32 hwirq;
158
159 do {
160 hwirq = xintc_read(irqc: primary_intc, IVR);
161 if (unlikely(hwirq == SPURIOUS_IRQ))
162 break;
163
164 generic_handle_domain_irq(domain: primary_intc->root_domain, hwirq);
165 } while (true);
166}
167
168static int __init xilinx_intc_of_init(struct device_node *intc,
169 struct device_node *parent)
170{
171 struct xintc_irq_chip *irqc;
172 int ret, irq;
173
174 irqc = kzalloc(size: sizeof(*irqc), GFP_KERNEL);
175 if (!irqc)
176 return -ENOMEM;
177 irqc->base = of_iomap(node: intc, index: 0);
178 BUG_ON(!irqc->base);
179
180 ret = of_property_read_u32(np: intc, propname: "xlnx,num-intr-inputs", out_value: &irqc->nr_irq);
181 if (ret < 0) {
182 pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
183 goto error;
184 }
185
186 ret = of_property_read_u32(np: intc, propname: "xlnx,kind-of-intr", out_value: &irqc->intr_mask);
187 if (ret < 0) {
188 pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
189 irqc->intr_mask = 0;
190 }
191
192 if (irqc->intr_mask >> irqc->nr_irq)
193 pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
194
195 pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n",
196 intc, irqc->nr_irq, irqc->intr_mask);
197
198
199 /*
200 * Disable all external interrupts until they are
201 * explicitly requested.
202 */
203 xintc_write(irqc, IER, data: 0);
204
205 /* Acknowledge any pending interrupts just in case. */
206 xintc_write(irqc, IAR, data: 0xffffffff);
207
208 /* Turn on the Master Enable. */
209 xintc_write(irqc, MER, MER_HIE | MER_ME);
210 if (xintc_read(irqc, MER) != (MER_HIE | MER_ME)) {
211 static_branch_enable(&xintc_is_be);
212 xintc_write(irqc, MER, MER_HIE | MER_ME);
213 }
214
215 irqc->root_domain = irq_domain_add_linear(of_node: intc, size: irqc->nr_irq,
216 ops: &xintc_irq_domain_ops, host_data: irqc);
217 if (!irqc->root_domain) {
218 pr_err("irq-xilinx: Unable to create IRQ domain\n");
219 ret = -EINVAL;
220 goto error;
221 }
222
223 if (parent) {
224 irq = irq_of_parse_and_map(node: intc, index: 0);
225 if (irq) {
226 irq_set_chained_handler_and_data(irq,
227 handle: xil_intc_irq_handler,
228 data: irqc);
229 } else {
230 pr_err("irq-xilinx: interrupts property not in DT\n");
231 ret = -EINVAL;
232 goto error;
233 }
234 } else {
235 primary_intc = irqc;
236 irq_set_default_host(host: primary_intc->root_domain);
237 set_handle_irq(xil_intc_handle_irq);
238 }
239
240 return 0;
241
242error:
243 iounmap(addr: irqc->base);
244 kfree(objp: irqc);
245 return ret;
246
247}
248
249IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
250IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);
251

source code of linux/drivers/irqchip/irq-xilinx-intc.c